Document ppwRnkB5551aaXX06jJLVekn6

IN THE DISTRICT COURT OF HARRIS COUNTY, TEXAS GORDON, et al., Plaintiffs, vs. BOB SCHMIDT, INC Defendants. ) i ) ) ) No. 93-42852 ) ) EXHIBIT NO.. 3 WORLDWIDE COURT REPORTERS, INC. JOINT AFFIDAVIT OF w -- . -- D. CHILDRESS AND JOSEPH A GTJTMOND Before me, the undersigned authority, on this day . personally appeared Jimmie D. Childress and Joseph A. Guimona,who oeina duly sworn, on their oath, did state as follows: 1. I, Jimmie D. Childress, am over the age of 21 and am fully competent to testify as to matters set forth in this affidavit. I am a former Corporate Safety Director of Intermet Corporation, which included nine foundries located in seven states. Before that time, I had worked at various jobs in foundries for approximately 30 years. I have received formal training regarding OSHA requirements applicable to foundries. I currently serve on the American Foundrymen's Society Safety Committee, and have served as Chairman of this Committee. I also serve on the Executive Committee of the National Safety Council's metal section. During the past several years, I have worked as a consultant to various foundries in connection with developing programs and policies to guard against recognized hazards associated with foundry work, including the recognized hazard of silicosis, and to ensure compliance with governmental regulations and standards, as well as industry standards. 2.. I, Joseph A. Guimond, am over the age of 21 and am fully competent to testify as to matters set forth in this affidavit. I hold a B.S. degree in Mechanical Engineering and have been the President of Joseph A. Guimond.& Associates, an environmental consulting organization, for more than 25 years. As par. cf my work during this line, I have provided consulting services to many foundreis. As a resulr cf chat wcr>;, I nave ceccne very fan!liar with foundry processes and procedures, as well as risks and hazards reportedly associated with these orccedures, including the reported risk cf silicosis. I am. also generally familiar with industry guidelines as well as governmental rules and regulations which apply tc foundries, oarticularly regarding the monitoring, control, and prevention cf reported hazards. I am a member of various organizations, including the American Foundry Association and the A.ir Pollution control Association. 3. Foundries typically must use large quantities cf sand in their operations. Among other things, foundries use sand to make molds into which they pour molten metals to form castings. Foundries also use sand to make cores, which they place inside of molds to form the hollow interior of castings. Sand is an essential significant component in foundry operations and has been so for many decades. 4. For many decades, foundries have been concerned; about the reported hazards of breathing sand dust, including silicosis. For example, since the early 1900s, various foundry trade organizations, such as the American Founarymen's Society "AFS", have sponsored and produced numerous conferences, seminars, and symposia specifically aimed at educating foundries acout the reported hazards of breathing sand dust and about ways to reduce or eliminate these reported hazards. True and accurate copies of AFS publications describing some of the information presented at these events are attached to this affidavit as 5. For many decades, A.F5 and other organizations also nave oistnbuted and made available to foundries various publications, including the journals entitled "AFS Transactions" anc "American Foundryman." These publications have included numerous articles which contained discussions about the reported nazard of breathing sand dust m foundries, including silicosis, anc guidelines for reducing or eliminating this hazard. AFS and otner organizations sent these types of articles and guidelines to countries as early as the 1930s. True and accurate copies of some cc tnese articles are attached to this affidavit as Appendix 2 6. Since the 1930s, foundries have been knowledgeable and sophisticated regarding the risk and means cf preventing silicosis. As a result cf this knowledge, foundries have instituted various protective measures to protect their workers against the risk of silicosis, including ventilation, dust collectors, and the use of respirators. 7. For many years, foundries have been subject to various federal and state laws and regulations that required them to be knowledgeable about the reported hazards of breathing sand dust, including silicosis. Regulations cf the Occupational Safety and Health Administration !"0SHA") required foundries, among other things, to keep respirable silica dust levels within certain limits. See 29 C.F.R. section 1910.1000 si seg. For many years, federal and state governments have enacted legislation and regulations applicable to foundries which addressed this reported hazard. 8. Where respirators were necessary to protect the health cf the employee, employers such as Central Foundry were required by federal law to establish a "respiratory program, " arrd set forth various requirements of a "minimal acceptable program," including the following: establishment of "written standard operating procedures governing the selection and use of respirators"; selection of respirators "on the basis of hazards to which the worker is exposed"; instruction and training "in the proper use cf respirators and their limitations"; routine inspection of respirators and replacement of worn or deteriorated parts; "appropriate surveillance of work area conditions and degree of employee exposure"; "regular inspection and evaluation to determine the continued effectiveness of the program"; and selection of respirators "from among those jointly approved by the Mine Safety and Health Administration and the National Institute for Occupational Safety and Health under the provisions of 30 C.F.R. part 11." .R. 1910.134 fb; . 3 Jimmie Childress SUBSCRIBED AND SWORN TO BEFORE ME on this 3^ day of1998, which_witnes^ my hand and seal of office. /8dZr /( My Commission Expires: 4 I SUBSCRIBED AND SWORN TO BEFORE ME on this day oftnP&L, 1998, wftirtr'witness -my--hand_and seal of office. My Commission Expires: i. E "1 45 `I X S'" 1 * Li" ' : ' SYMPOSIUM ON FOUNDRY DUST CONTROL (?<$ June, 1947 t TU 5 ^ 7 j i\ i. i i Published by Amniran ^omtbr^m?na Afifinriatinn Technical Development Program 222 W. Adams Street, Chicago 6, 111. \ EXHIBIT -- Table of Contents 7V,Hoods and Piping for Foundry Dust Control Systems--By E. A. Carscy........................................................................ t Centrifugal Dust Collectors--By H. C. Dohnnann...................................................................................................................... 3 Cloth Type Dust Collectors--By G. A. Boesger.............................................................................................................................. P Wet Type Dust Collectors--By A. S. Lundy..................................................................................................................................... 13 Fans and Exhausters--By *P. Cohen.................................................................................................................................................... 16 Maintenance of Foundry Dust Control Equipment--By K. M. Smith................................................................................ 20 t in INTRODUCTION By W. O. Vedder* Modern industry has substantially increased the overall dust problem with the foundry industry con tributing its share as a dust producer. The dust problem in the foundry has become more complex because of accelerated production, new methods and materials, the labor market and scarcity of materials. New methods and materials have resulted in diversification of foundry dusts so that they now include those classified as hazard ous down to those which are just plain nuisances. Generally speaking, the advantages in foundry dust control cannot be measured directly in dollars and cents but usually lie in intangible benefits, such as, elimina tion of hazards, improved working conditions and re duction of maintenance. The foundry industry does not have the advantage of some of the other dust producing industries that obtain a return from the salvage value of the collected dust which can be credited against in vestment and operating costs. Fuundrv dust control is accomplished bv sev eral meth ods 01 combination of methods: 1. General ot dilution ventilation 2. 1'ulation or segregation of hazardous operations . Substitution of non-haznrdous equipment, matc- tials or processes 4. Dust allaying media, such as wetting or oiling j. General plant housekeeping and cleaning . Personal respirators protective devices, and 7 Exhaust sv stems. P.inizljoin (oip, ] t ji'crsiO's n, Md The exhaust system is more v\ idcly and effectively applied than any other dust control method. The con ventional dust control exhaust system consists of three basic component parts: 1. Exhaust hoods and piping system 2. Dust collecting equipment, and 3. Exhauster and drive. The exhaust system functions by producing air move ment directly at the source of dust production causing the dust-bearing air to flow into the exhaust hood mouth and thence through the piping system to the dust col lector. This air movement should, if possible be in the direction of, and thus utilize any motion transmitted to the dust-bearing air as a result of the operation or process. Air flow is maintained through the system by an exhauster driven bv a motor. All of the component parts of the foundry dust col lecting system are important and if effective results are to be secured, the design of all parts must be carefully co-ordinated since poor or improper design in any one element will result in poor overall results and unsatis factory performance. An effective efficient exhaust sys tem constitutes something more than a group of sheet metal hoods and pipes connected to a fan. The design of foundry dust control exhaust systems is a field of engineering icquiring special training and experience. HOODS AND PIPING FOR FOUNDRY DUST CONTROL SYSTEMS E. A. Carsey Assistant Chief Engineer The Kirk i Blum Menufecluring Co. Cincinnati. Ohio HE first step in planning a Twell engineered foundry dust control system is selection and fitting of a proper and correctly de signed hood to the source of dust. The source of dust is located and the hood is placed at this point, to ieduce the dust concentration to that within s.ifc limits of hygienic standaid' Tiie second step deals with air voiumc. which is calculated to pro duce the desired result. This volume determines pipe sizes, actual hood openings and selection of exhaust equipment to produce the desired air flow. T he third step involves details of construction, 'in h as hood and pip ing gnugi-. proper clearances, and the s.ifcn, comfort and visibility of operator. Adherence to American Foundrvmcn's Association and State Codes is checked and finally the de tailed plan of dust control system i' ready for preparation. Hood for Shakeout Since the- crane operator requires masmumi of visibility for unhampi-ied handling of flasks, the use of an overhead hood is sometimes pre cluded For this reason the "side" or "cross draft" hood is usually con- Prcsrntcd at a Session sponsored by the S.iOts and Higicne and the Plant and Plant Equipment Committees at the Kifurtn Annual Meeting of the Amer ican Foundrv-turn's Association at C.leve- ' M > f IQ4C siderrd (Fig. 1). The cross draft hood does not have a roof or full extension over shakeout grate and. therefore, it is natural that a much greater volume of air must be han dled, resulting in excessive power costs and heat losses. It is well known that velocity con tours of controlling air decrease quite rapidly as the distance from hood intake increases. This means that the foundry operator must in crease power consumption approxi mately 100 per cent to operate the cross draft hood, in comparison to an overhead type or enclosure hood. The answer to this problem could he a compromise between the straight "cross draft" and totally enclosed hood, as illustrated in Fig. 2. Perhaps this compromise could be accomplished by means of a pneu matic finger ranopv arrangement, hal ing rather i losclv spaced inuiul A Selection and fitting of a properly and correctly de signed hood to the dust source is the first step in planning a well engineered foundry dust control system. The required air volume determines pipe sizes, actual hood openings and selection of exhaust equipment to produce the desired air flow for effective dust removal. Hood and piping gouge, proper clearances, and the safety, com fort and visibility of operator must be considered in designing the dust control system. canvas "fingers" possiblv 8 cr 10 in in diameter. They would be held in a horizontal position over the grate by means of a small supply blower mounted alongside the shakeout hood or on top. The space between tubes or fingers would af ford visibility to the crane operator and the chains would slide and work their way between the lubes, with little or no difficulti. Such a design would save FiO to 7"i jrer cent ol power costs, in cuiiipariw)ii to straight shakeout cross draft hood. This is a typical exam ple of the specialized design possible in foundry hoods, which is "step one" in dut control. Snagging and Cleaning Snag and cleaning departments in a foundry ofTcr another oppor tunity to improve hood drsign (Fig. '!). Here, it is possible to npplv pedal operated turntables, built to a < nm enient height of operator, so that smaller castings are turned and operator grinds into a fixed hood position. Of course, if the castings arc larger, the cylindrical type downdraft tabic arrangement is pre ferred (Fig. 4). If floor gratings arc used, movable vertical screens or baffles arc of as sistance in directing the light grind ing dust downward. The i onvevor transfer points, elevator hoot and head connections, shaker screens, mixers, mills, aerators, tailings hop pers. tunnels and the like can be usually handled with direct ioctangu lar to round and overhead hooded connections. Giinditin Ofmalinnr. Individual grinding stands or groups of wheels an-served In ln-.ivi dull til.ite ho,nh Hoods and Pii-inc fok Fcu-nory P -: C s ^: _.j-..ii:^iIa^;":a"ii-^-S;SKSJsSin5hr?i;ifi?iw--s;aiii"-->r;-m~;r~--a....------- fin. 1 (Top)--Side or cross draft hood in connection iL-ilh the mold shakeout operation. Fig. 2 (Right)-- Pneumatic finger canopy type of hood, a compromise better cn the straight cioss diaft and the totally enclosed hood (Patented). wme with traps built immediately below intake while others have traps in the vertical exhaust to the rear of stands (Fie. 5). Foot rests some times arc incorporated into dcsien. and sides and tops arc hinged for wheel replacement or dressing. Fig '--Pi da! operated turntable in the foundiY snagging and cleaning tie pat tmrnt Sote cross diaft hood ai langrinent. A large individual grinding wheel, either vertical or horizontal always proves an interesting problem, h is advisable to consider wheel replace ment and locating the point of ex haust as close to a perfect tangent, to material leaving the periphery of wheel, as possible. Sometimes on larger wheels the complete top half of hood is removable for wheel teplacement. The safety of these types of hoods, however, should be the paramount (oiisideralion. Accidents have been leeorded. wheie the lace opening of hood was too great and lasting' would become lodged between side ol hood and wheel itself. The horizontal grinder frequently has its own exhaust connections built in bottom. It is then onlv necessary to utilize a circular header at the bottom of grinder to collect the vari ous point' of exhaust. Figure 6 illustrates a wet grinding application utilizing heavy dul\ steel plate hoods, with provision for reads removal of the hoods and wheels, by means of an overhead chain fall. Mold Cooling Tunnels. Special consideration is given to the design of mold cooling tunnels (Fig. 7). These hoods arc built from the floor. having a semi-circular top and served by one or two vertical ex haust slacks with fans built into stacks themselves. Removable sec tions are provided for applying and removing weights, if desired. Condensation Imps. Condensa tion traps are sometimes used in the branch lines for the purpose of re ducing moisture content which is always undesirable where accom panied by solids and dust particlein the air stream. Heave black steel piping with electric welded seams and joined hv rumpon-ion angle con nections i- used wheie uinperatuies Fig. 4--Cyliiiihital type do:rn diaft table ai iniigi ineiil jui snagging and cleaning eastings. K. A (JERSEY FiC- 5--Dint tewanng arrangement lot individual ginidin* stands and : 10nt>s of grinding wheels. Air Volume and Piping Size In most instances, in foundry proper, space bring at a premium, the hood equipment and piping fiom the hood- mu<t be built into extreme!'' limited space This leads us into steps two and three, or tlv ini|)ortant phase of determining air volume and piping size. Not until relatively recent vrnrx has the problem of pipe design been given its just place of importance in modern foundry dust control sys tems. \\ c keep rediscovering peri odically that piping plays a major rolr in good foundry practice and although the design and ideas are somexvhat different and slightly more advanced in the last quarter air foimcri iron- m- : n-:.. u>. . providing three tiiick11. --. - o: . seam romplctelx around hi. cm*'' at each crimp. The mnjonix of fonndix nipiiv, installations make use oi caivamrec: iron or steel, rixcted and soldered longitudinal and cnvunifcirntial scams. Gauges of piping ranee from No. 18 gauge for small diamnei pipes through No. H catigc for larger sizes. Elbows are at least two gauges heavier. Ofien old dim control sx>trms mav be modernized hx rear ranging. balancing and replacing piping, resulting in inrreased rfhcirncy. Piping Diameter Its determination is a smdx in itself. Present day foundry piping design is customarily based on vr- iaci'i c: inn- J` l ihmi:i1 stiunural { niifiiliihi- .uc nii'Minlrri-d as itlti>tiau-d h\ no" draft fume exhaust "\ -inn I ig 8 . Cleanoui- arc ii'ii.ilh placed at in )! irinci' along Mde nl header nr main pipr for cleaning. inspection and innmtrnant c Discharge stark' iMindiii; xcrtirnllx through rnnf max hr equipped either xxith ram lap Pr'c i-llioxx. cm tapered static i ga in a rt inn Tin most efTu lent xtai k Iciminatmn h. of rntiixr. the slightlv tapeied n "am nozzle xx hit'll ion'cu- 'omi of the x-elocitv pressure hark into xtaiie The rain rap and eihoxx ofTei some protertion against " rather hut incur a slight additional hack prcxMue to ait discharge. Pattern Shop Pattern 'hop ha- its dtot control piohlem. However. ltcrc \xc have w noeixx orkincr 'havings. chips and xaxxdut rathei than foundrx abra sives. The hood' and piping ran be somewhat lighter in gauge, but nevertheless, require careful plannine and expert fitting to the xxood"oi king machines iFig. 9). Fig. 7--Mold eoohng tunnels. irnunx. the basic fundamental' are the same. Fittings mid Cornu t tiom. Fittings and connections arc used xxitll hr.mrhcs brought in at \ rrv gradual ancles and eihoxxs are provided xx ith throat radii resulting in a minimum ol friction loss to air and materia! flow. Sinre the maximum amount of xx cat in an eihoxx takes place at the heel, opposite side from throat, removable plate' are provided here which reeeixe the wear of the abra'ixr materials handled in air stream, and are replaceable making it un necessary to change elbow itself. I he heavy duty "one piece" elbow is usually seen in modern installa tions. This elboxx, by virtue of be ing formed from one piece of sheet metal, has but one throat seam and no rix ets to wear. The girth seams Fi". 8- (Above)--Cross dtaft fume exhaust system in ennneetion with a condensation trap. Fig. 9--Dust conhol system in a wood pattern shop. 4' litmus and PiriNu )ok Foi'M'ks Comkol Sx>ti.w> Fn. IQ 'l.i'!'--- 7 " c r . i i "i.uo! t .T.T; n- r. .> e ....... lit" Ci'.'.'. ( i. ' : locitics ranging from 3600 to 4300 fpm. or velocity pressures from 0.8 through 1.3 in. of HrO. It is desir able to maintain as constant a ve locity pressure a1- possible and some times cut-offs arc provided and locked in a fixed position to accom plish this means. The computation of losses in the entire piping system must be care fully worked out. and a study of hood entrance losses with cquiva- ii nt lo" m pen I'liiatT'' <>: 'rin. ir. pressure. plus iine.i! fiictio:: inv- o pipe in static, brunch and elbow losses, plus pics-ure drop across preeleaning and exhausting cipnpmcnt determine the total pressure at which the systems would operate. Round piping is usuulK preferred to oval or elliptical and <mrr the static pressures ate quite Inch, in material handling s\ stems. rretancular and square ducts, if used must necessarily have a good deal of brac ing to present vibration. Finally, ing of pipe as the smaller sizes used caution should be exerted in the sizwill incur considerable more power consumption if selected for veloci ties above 4300 fpm. Figure 10 shows the termination of dust control piping in a large combination collection unit, the size of which may hr approximated bv the men in lower right hand eorncr. CENTRIFUGAL DUST COLLECTORS H. C. Dohrmann Buell Engineering Co.. Inc. New York. N. Y. The writer discusses trap type, common cyclone type, and the volute or spiral type of centrifugal dust collectors. Centrifugal type dust collectors utilize radial acceleration of a gas stream for seperating solid particles suspended therein. The fundamental operation is separation of dust particles from the main air flow into a quiescent zone, settling out by gravity into a receiving hopper. HE ba<ic principle employed height of the particle above the bot T in centrifugal type dust col lectors is the utilization of tom and inversely proportional to the settling velocity of the particle. radial acceleration of a gas stream It is apparent from a consider for separating solid particles sus ation of practical values of the fore pended therein. Various designs arc going factors that separation of dust in use ranging from the simple trap, in which the particles arc thrown by this means usually involves units of impractical size. In the centrif out of the gas stream by virtue of a single change in direction, to the high efficiency cyclone wherein the chance in direction of the air stream is continuous throughout its passage through the cyclone. ugal collector the force imposed on the particle is a function of the radius and velocity of rotation and may be of much greater magnitude than the gravity force, so that the distance of travel required for sep In all such collectors the funda aration of the particle to the collect mental operation involved is the ing surface is reduced. separation of the dust particles from the main air flow into a quiescent 7onc. where thev can be settled out bv gravity in a receiving hopper. The maintenance of a minimum radial width of the entering gas stream will also require a minimum length of gas path. In the high ef Dust Particle Separation This requires that the particles move across the stream, but such motion is opposed bv the aerody namic resistance on the particle, the magnitude of which is a function of the particle sixe. shape and surface qualities The velocitv of the par ticle relative to the air stream will depend upon a separating force im posed on the particle against this rc-istancc. In an ordinary settling chamber Fig. 1? the separating force is the gravitational force and in the ab sence of turbulence the horizontal distance of travel required to settle out a particle is directly proportion al to both the air velocity and the ficiency cyclone type centrifugal col lector of proper design the down ward spiral flow pattern produces the maximum length of gas parts in the minimum space. An analvsis of these fundamental factors, will, in general, indicate the relative separating ability of the various types of centrifugal collec tors Actually the problem is more complicated due to velocity require ments in the region of turbulent flow and the presence of secondary flow components. However, consid eration of these factors is heyond scope of this paper but it can he stated that various designs have been developed to minimize the ef fect of these conditions. Trap Type Collector Prcsrnicd at a Session sponsorrd bv ilic Safety and Hycienc and the Plant and Plant Equipment Committees at the fiftieth Annual Mcetinc of the Amerman Foundrvinen's Association at Cleve land, Mas 6, 1D46. Simplest of centrifugal collectors is the trap (Fig. 2). It should be noted that the length of the gas path is extremely short which is a partic ular reason for its being ineffective except on particles of large mass. Modifications of this design have been developed using multiple vanes in an attempt to improve the effi ciency but the inherent disadvan tage of a single change in direction of flow would indicate a rather def inite limitation to the gain that might be attained. Common Cyclone Type Collector So-called common cyclone (Fig. 3) can be considered next in order, with reference to separating ability. These units arc of relatively large dimensions on the basis of gas vol ume handled as indicated by the large ratio of cyclone diameter to in let diameter. While the inlet veloc ity is generally of the order of 50 ft. per sec., the true cyclonic action is not in evidence because of the large gas volume within the cyclone compared to through-put volume. The large dimensions provide a long holding time but the low rota tional velocity in these units means a low separating force on the par ticles. The application of these units is therefore usually limited to rather coarse dust. Volufe or Spiral Type Collector Next design to be considered is what we might rail the volute or spiral collector (Fig. 4). This us ually takes the form of a scroll sim ilar to a fan casing except that the flow is in the opposite direction. Usually at about 270 F. from the inlet a slot or slots arc provided for passing the dust thrown to the pe riphery into a hopper or secondary collector. The gas follows a spiral path 6 Cuntkii t\; Dim Coi.t i.ctoks Fit: I-- Sl.ittl> t'l irtthn" chamber iffustralirry' ii ltJni" of Hint portiilcs. mu ard the center and leaves through a eentral opening. Vanes are sometimes provided to form a cylindrical baffle so that the gas is made to reverse its direction before leasing as a means of further im proving the separation. This design has in some eases been used to form the inlet boxes on fans thus incorporating a fan and FiC 2--Sketch of trap t\j<r cni!>:!,rpal colled u shntrtng u ltimo of <!:/! panicle.;. collector as an integral unit. It is essential that a proper withdrawal of the separated dust is attained to assure a definite flow through the slot into the collecting hopper or secondary collector. This gas flow must necessarily rejoin the main stream and the required pressure differential may be obtained by con nection to a point of low pressure or the use of a small fan capable of handlin': the shunt flow. Essentially, the length of path is limited to less than one revolution although some designs arc propor tioned to provide for recirculation (Fig. ft), in which rase the distance is increased with a corresponding in crease in efficiency. However, the comparatively large dimensions re quired means a low separating force so that here again the application is limited to the coarser dust. High Efficiency Cyclone At the present stage of the ait the high rfflnoiuv evclone fl'tg. 61 i- the most efTrctive centrifugal colIrctoi available. There are uinnv variations of this type but in general they have an inlet at or near the top with the greatest diameter at this point and taper down to a small diameter dust discharge opening at the bottom. I hr gas outlet consists of a con centric tube extending down into the evclone at various distances from the top. The flow pattern takes the form of a descending spiral at the periphery and an ascending spiral in the center. The gas rotation is achieved either by an inlet tangential to the evclone body and the outlet tube. In the latter case directing vanes are disposed in thr annular space to impart a iot.itiona! new m the en tering stream There have hern main attrmpis toward mathematical .mah-is oi > \ clone operation and esiahlishtnen: of basic equations However, the romplexitv o: the main factors in volved has prevented am great de gree of success along these lines. At best am equation' that have Ivcen evolved have hern Innitrd to units of particular design proportions. Most of the uoik done in the de velopment of high effirieiiev cvelones has therefore liecn of an em pirical nature. In the case of de signs. with which the author is con cerned. individual experiments have run into the thousands. In view of the effect of dimension al proportions on the performance of cyclonic collectors, it is under standable that various investigators have evolved different concepts as to the relative importance of the vari ous factors and have concentrated their efforts on designs in which one in particular is stressed. , Various Factors Considered However, a proper balance of these proportions is essential since extreme values of one particular fac tor. while tending to produce higher efficiency may effeei other factors to a greater extent in the direction of lower efficiency. By way of illustra- //. 0--Sketch of common cyclone type oj dust collector. H C. Doiirmavn tion let us consider some of the con ditions which promote good per formance in a cyclone. h is fundamental that at a given tangential vdocitv the separating feme on the particle is greater at the smaller radii However, this does not mean that a small diameter unit i- inherently 1 moie efficient than "in "I large diameter, although it dm - mean that a smaller diameter unit ol paitieular propoi lions is inhen nth more efficient than a large diameter unit of the same propoi lions. Tin. distinction lies in the fact that m a unit of diameter D taper ing down to a dust discharge of 12 D the separating force at the di-eh.it ge n about eight tunes that at tin inlet w Ik 11 .is m ,i milt of diaown i 21) and tlnsi disfh.nge dia meter 1 ,'2 D. the separating force at the discharge is about 64 times that at the inlet or about eight times that in a unit having a diameter only 1 /2 as large. This would indicate that a small ratio of dust outlet diameter to cyclone diameter is essential. However, it is aho necessary to haw a large ratio of overall height to i yi lone diameter. It is icadilv appateul when we consider that if tlie evi lone tapers too sharply the vertical component of the reaction of the conical wall to the centrifugal force on the particle may prevent its downward motion to the collecting hopper. The iadi.il width of the inlet is also an important factor since both tlicorv and practice indicate that with a decrease m width an ini lease 111 illnirtuv i an be expected. 1 ill I' I - " min.. .. to ti des're a si' wiiiir "'.in I i ii i. >i *1 : K- i - -mam the <amc simi it -tim- a. pronchcs the c.i'i or the oidm t eve lone having a i..ig'. rati" s': (\ t Is'nc volume to liuougii-pu: vo- nine. The position and diameter ol tin gas innls t pips' will eliect tin s'/ii- cicncv ol a given unit. The dentil to which these plus's should exts'iid below the top lor bs-st ps i lot mance cannot generally be stated Mine it is more rommonlv related to the over all design but a ricciensc m it- di ameter. will, in general, mean an in crease in rfffu ienev as well .o in crease in pressure drop. The foregoing discussion has lieen confined to the design of single ele ments. In practice, it is generallv found expedient to use multiple elements, having common inlet' and outlets and discharging to a com mon hopper. It is essential in such l:ip. C--Dio^tnin of a hih tffirinny ryi liiiir lyjit tlttil / otlri tot. fng -5--Another sl.rtrh of volute oi sjjnnl typo HuU eolleeloi provided w.lh ii'i .) dilation. 8 Ckm KiFrcrV>7 C.ct.t t m ors case.' that the individual element* equally share the load, since anv in equality will result in circulation be tween element* by way of the hop per. thu* reducing efficiency. The design of the inlet and outlet should therefore insure proper di*tribution to the elements. In the high efficiency type of col lector the action of the vortex uherein high spin velocities obtain at the dust discharge, the static pres sure in the hopper is usually lower than the static pressure in the gas outlet. This means that even with the collector on the discharge side of the fan a negative pressure can ex ist in the collecting hopper. It is therefore essential that the hopper be properly sealed at all times against any inicakagc since ad mission of air to the hopper creates an upfiow into the cyclone* which has the effect of materially reducing the efficiency. With regard to applications in the foundry the centrifugal type collec tor has a definite place on various operations. They have been success fully used on knock-out and shake out screens, on sand blast and shot blast machines, as well as grinding and polishing operations. It must be borne in mind how ever that in view of its inability to cpa rate romuieiris all the mi-: from the air stream the exh.m-t air should not be returned to the ing area but should i' exhau-ieb out*idc the buiidme In conclusion, it mat he stated that progress is still being made m improvement' in design and net fonnanre of eeittriiuga! type eoliei tors and while gam* ran he made to improve the inherent chat .ictcri'itr of decreasing cfJiciencs with de crease in particle size, it i' believed that complete collection of the ten small particle sizes of the order of five microns will have to be achieved by some other means. CLOTH TYPE DUST COLLECTORS George A. Boesger THc W. W. Sly Manufacturing Co. OcvtUnd Cloth type filters collect finely divided dry dust at economical cost. Two general de* signs are available--the tube or bag type and the screen type. Mechanical members which support the doth envelopes are connected to a rapping device for dislodging the dust pack from the cloth surfaces. Hoppers are provided below the screens into which the collected dust is deposited. LOTH-TYPE filters remove C dust from the conveying air by flowing the air through specially designed filler fabric. Sev eral variations in design are avail able. but the operating principle re mains the S3mc. The cloth-type filter is in general use primarily for the collection of finely divided, dry dusts, and accomplishes high recov ers- at economical cost. With the exception of the far more costlv electrostatic >prccipilalor. no dust collecting device can equal the doth i ollecior in efficiency. Collecting only the l.ugrr panicles sit du-t c'ises the appearance of being rllective because it due- eliminate .1 latgci part of the vi-iblc nuisance. Hossevei. there arc tince reasons for collecting the fine dust: 1. Coarse dust particles settle near the point where the diM i> created, but the finer particles llo.it in the ait and become a mii-aiue and (ic.iu damage at i onsidei able ilit.uu < 1 rom the mum re. 2. 1 It av\ dust particle's lll.iv seitlc on a piece of maihincrv. Inn onlv tiie vert fine particles work their ssa\ into bearings to cause irrepara ble damage. 3. It has been scicntificallv deter mined that larger particles of dust are stopped in the nose and throat of an exposed person and that onlv the finest particles find their wav into the lungs. The clolh-tvpe collector is most adaptable as it will handle dust of Presented at a Session sponsored by the Safets and Hscicnc and the Plant and Plant Equipment Committees at the Fiftieth Annual Meeting of the Amer ican Foutidrvmcn's Assoeiation at ClrveLnd, M.O 6. 1946. any size. No dust is loo coarse or too fine for the cloth collector. A cloth filter consists of a tight casing en closing the filter fabric, and so ar ranged that all incoming air must pass through the fabric to the col lector outlet. Dust Particles Filtered Upon entering the case of the col lector a reduction in air velocity occurs, serving to drop the coarser partis U-s of material from tin- air -iit-ain. The remaining finer diM is lomcved to the cloth surfaces where il is filleted from the air stream, the cleaned air continuing on through the t loth to the i ollecior outlet. The dust pack, or mat. thus formed on the cloth surfaces assists materially in improving the over-all recovery efficiency. T he collector rasing is provided with hoppers into which the rollei ted du-t o deposited. T he filter i- litled with a 'll.iking device de signed to dislodge pel iodii allv the (hist fioin the i loth surfaces. T his shaking operation occurs with air flow shut ofT. since the air pressure would otherwise tend to hold the dust pack against the fabric. Installation Types A connection may be made from the collector to the discharge side of the exhauster as a "blow through." or pressure-type installa tion: or to the inlet side, designated as a "draw through." or suctiontype installation. The latter ar rangement is most generally adopted because in this case the exhauster, or fan, handles only clean air and is not subject to abrasion by the dust particles. Cloth Filter Designs Two general designs of cloth filters arc available--the tube or bag tvpe, and the screen type. In the cloth tube or bag type, the filter fabric takes the form of a scries of tubes or bags, open at one end and closed at the other. These tubes, or bags. aresuspcnded vertically in (he casing with the bottom, or open end, tightly sealed to thimbles in a plate located near the bottom of tin- casing. The dustladi-n air culcis the casing below the seal, or thimble plate, and passes uim.ud through the i loth inlets { Fig. 11 Dust is precipitated on the inner surfaces of the lubes, or bags, and the cleaned air continues on to the outlet at the vide, or top of the casing. The tubes, or bags, are at tached to a shaking device, usually connected at the top of the tubes, wliiili is operated periodically to re move the dust pack f11ii11 the inner surl.nes of the fabric, from which it drops to hop]HTs which form a part of the collector casing. Cloth Screen Collector The doth screen type collector is of more recent development. In this type of filter the cloth appears in the form of comparatively flat en velopes suspended horizontally and vide by side in the metal casing, in a manner which permits installing a maximum cloth area in a mini mum size of casing. Open ends of the cloth envelopes arc sealed to each other or to the casing, definitely dividing the casing into a dust chamber and a clean air chamber. The dust-laden air enters the dti't side of the easing and must 10 Ci rv> n 1' i r>. '* C 'i i i 'toks i Ckf ** * f* Fig. 1 (Left)--T. Inca! doth type dust colleetoi installed outside oj a fvuudiy. Collected dust is teilhdiau n from the hoppers. Fig. 2 (Above)--Diaciam shows passage of air thiough a cloth type dust eolhetoi. p.is- through tilt.' cloth hum the uut'iiit- ii> lilt-- inside of tlu- envelopes. The dust is collected on (lie outside ill ilir envelopes. Me < h.iilicn) mcmbet.- w )iic!j supjr-'ii llu- i iolli envelopes are cunni-i ii d lu a "linkni" or rapping d<`\ nr fui rii-lodging tlic dust pack imm the cloth surfaces. Hopper' aie piovided lielow the screen' into which colli t ied du't is deposited. M.tnv refinements in cloth co!lertor design have resulted from e n t e n s i v e operating experience. Thcv have brought about lunger life: greater capacity per unit of space occupied; ease of access; re duced maintenance and repaiis: and more effective cloth cleaning. As the building up of the dust mat on the cloth surfaces results in a gradual increase in collector re sistance. it is neccssaiv periodically to vibrate the cloth surfaces to re duce the dust park and the resist ance to air flow. With the more common collector arrangement, known as the intermittent tvpe. the (loth is cleaned hv periodic opera tion of the shaking device, with the r\b.iii'lei 'Inn down Fiic|ucnc\ and duialion of these (leaning periods is deteimined bv specific condition'. For average problems with average dust loading, these cleaning periods of 5 to 10 min. may take place after each 4 to 3 hours' operation. The cleaning period frecjiiemh can be decreased 1'ig 2 !Left}--Diugiam of an passage in an aulomaUccontinuous du>i him. In this diagiani both fdter sec tions F and C handle the dust-laden air. Fig. 4 (Cen ter)--In this diagiam mam damper K is closed, small damper M is open for ieter.se ah-flotv thiough filler F, to assist shahet dine II in lemoral of dust fiom bags. Fig. 5 (Right)--lit this dta giant mam damper L is closed, small damper N is open for teecrsc air-flow through filler C, to assist shaker diire ] in removal of dust fiom bags. C. A. Bof.soer 1 In installing additional presenting inr.ui' .ahead of the dull) mllictor in udiuc the du*t loading on tiie I iutii. I nil i miltcnt tvpr of mill ftoi i> iioniuiiji.il in fust cost and mainii ii.mce for me null operation* anil ]iiiH t'M' when.- *hi>n shutdowns for (iolii tii.mm; aii' not deli imental. I la 'i livamng pi i iods ordinalil\ an- arranged to coincide with the iuncii period* or *hift change*. Continuous Type Collectors Cnmimioti* l\pr c lot 11 rolleetmi an mi il lor pime** application* "In H1 tin-i *lmld<>w n piimd' foi i i *111 i 11 .mine i .nmol lie | n i untied. aiiil i on11iitiiiih opoi.ilinn i* enenn.i! 1 2 ] in lull lumen* (vpi lollecioi inn*isl* of luo oi moie i iolii lilter i omp.n uncut', ot scenon*. cmli fitted with an individual *iiahmg dc\ ice and arranged with e.itci oi a.unpvi* to permit altcriiatelv j11i.11111o each compartment liom an fiou to permit cloth i IcanIlic, Tiii* control of air flow and diall ing ol the respective i ompni tinent* mav be accomphihed in regular ciclc through manual operation. or be automatic control apparatus. In `fine instances, involving the han dling of high dust concentrations, an evtra cloth filter compartment, or section, i* provided over .and above those iei|uired. with the control so an.umed that one lompailmenl i* luii'l.mtlv shut oil loi ele.mini:. Continuous i\pc lollia lots are sub stantially mole expensive fiom the standpoint ol fiisi cost, opeialum and maintenance than the intermit tent l\ pc coilei tor. T his i' paitieularh true uhen the installation i* of the automatic tvpc. necessitatin': electrical conttol and timing ap paratus. Pioperb applied and maintained, i loth fillers Mill pioiidc elTi elue mi|j|iicioii of fuck divided a* mil a* io.iisc inthisiii.il ihis|s. but si \ . ei.il f.iltol* lllll'l be given tolisiiU-i- .ilion m tiii n application T be mote important bmuuig l.n lois ,m n nipeiaturc. moislvne. and (liemie.il (jualines of hotb I lie dint and the (onvi'ving ;nr or gas. Maximum Operating Temperature T he limiting tempcinune for cot ton filter fabric is appioxiinatcb 17 i F. This limit mav be some, "hat extended through the use of "ool filter falnic. The use of as bestos. glass cloth or plastics docs not appear to be sati.sfncton- at this stage of development, bccauc proper physical qualities have not been developed to withstand the teqiiiionirnts of I hi' service. When containing moisture, the conveying air and collector tempera ture must lie maintained above the dr" point to pi event condensation within the coilei tor, winch might otherwise ii-sult in sludging the dust on the cloth surfaces. The i hemieal properties of the air. or gas. and the materials being handled, must be analyzed to determine if a deleterious reaction on the fabric or the collector parts is likely. Cloth Filter Factors Other factors governing the cloth filter lei'unmieiidation for caeli ap plication air the air volume han dled: n.uuie. i li.iiuctci istics and amount of man ual In lie lollcctcd; and range of dint particle size and spccifir gravity. The size of a cloth filter, i.c.. the filtering area, is govi ined hi consideration of these fac tors. Filtration velocity used with intermittent type collectors will vary with specific problems of average nature in the range of from one to four lineal ft. per min. This is more commonly termed ` ratio.'' meaning one to four cu. ft. of air per min. passing through each sq. ft. of filter ing area. With continuous type col lectors. the "ratio," or filtration ve locity. frequently is increased. High dust loadings are reduced In |in settling devices installed ahead 12 of the cloth filler. Tim presetting nm\ be accomplished bv a ccntrifupnl or cvclonc collector, settling or baffle chamber. or other devices effeenve for partial precipitation. Wire Mesh Spark Screen When connected to systems where there is a possibility of sparks or incandescent particles being drawn into the svstem. a wire mesh spark screen is installed in a compartment ahead of the cloth filter section for .trapping and extinguishing these panicles. This device is also useful for re movin'; or trapping nominal quanti ties of lint or fibrous material from carious classes of operation. The wire spark screen frequently is fitted with a rapping device operated front outside the casing for shaking down accumulated dirt and lint. As a fur ther protection in applications where sparks may occur, the filter fabric may be treated with a special flameproofing solution. When handling dusts of explosive oi combustible nature, doth filters should be fitted w ith vents, or stacks, arranged aulornuticalh to open and relieve pressure, should an explosion occur. Discharge of dust from collector hoppers should be given careful con sideration to prevent dispersing fine dust to the working room or the surrounding territory during the emptying operation. Standard cloth collectors arc provided with hoppers having dust-tight discharge gates fit ted with canvas tubes. By proper manipulation of the canvas tube the dust emitted during the emptying operation can be kept at a minimum. This is accomplished by twisting the tube before opening the hopper gate, then gradually untwisting it and allowing the dust to slide slowly through the tube to the receptacle or truck. The hopper gates are, in some instances, fitted with clamps for the attachment of bags to which the collected dust is discharged di rectly. Receptacles, trucks, etc., with tight covers connected to the hopper gates by removable spouts are some times used. A practice of considerable merit is to enclose entirely the space below the collector casing surrounding the hoppers. This prevents air currents from distributing dust which inav C.i.cnii Tym Di st CVl:.i ci.h-.s be'emitted ciurinc tii heppef' empmne operation Aero- to tin' hop per enclosure is liar! tin one.') a t:;i;: door in the end 01 muc A a Hirm-.-: step, the enclosure ran b' p;o\iiicci with an exhaust connection to mamtain a slight negative pies'uir therein and thus present emission of dust. When mechanical or continuous dust discharge is desirable, the col lector lioppcr- ,-jre fitted with lotarv air-lock type valves, which permit dust discharge but present air leak age, although the collector mav be in operation. The rotary valves or dinarily discharge into a tight con veyor for returning the material to the process or to a central disposal point. In some instances the dust is discharged from the hoppers into a water sluicing ststein and discharged as sludge into settling pits, lowlands or sewer. Acknowledgment The writer wishes to acknowledge assistance from Mr. Andrus, of the American Foundry Equipment Co., and from Mr. Vedder-, of the Pangborn Corp., in tiie preparation of this paper. WET TYPE DUST COLLECTORS A. S. Lundy Chief Engineer Cltudt B. SchntibU Co. Detroit A Dust particles, in wet type dust collectors, t are entrapped in a liquid, usually water, and conveyed by the liquid to a settling tank. Four general types of wet type dust collectors, namely, spray or water curtain type, dynamic precipita tor type, impingement type, and the combination types of collectors are discussed. 7 ET type dust collectors have a common basic operating principle. Dust particles are entrapped in a liquid, usually water, and conveyed by the liquid to a settlin'; tank or disposal area. General Types Tlie method of entrapping the dust particles varies with the design of the collector. The desired water patterns for collection are obtained b\ using a fresh water supply, recir culating pump, rotor, or the air stream itself. The types of wet col lectors .ue .a follows: i--Sprue or u.,tei curtain tvpe. 2 -- Dvnamie pi ccipitatoi tvpe. -- Impingement lypi. 4 -- Combination ol the above t vpcs. S/ntii oi hater nntani tyfir colhi lot In the spiav or water curtain t\pc dti-t laden an is drawn through one ot mote sialic' Tile water pat tern I- piodurid h\ nozzles, high air viloiitv. or a mini. A i onsideiable .miumi! ol Wall] is (allied upwald m tin air stir.on to the moisture i iimmator- where it is separated fiom tin air and drains downward flushing the surfaces. L'sunlh the liquid is recirculated after a settling period in an integral tank. A small amount of make-up i- requited to compensate for evapotation and sludge handling. Dynamic pici ipitator type callertut. In the wet type dvnamie prelipil.uor (Fig. 1) the collecting unit Presented at a Session sponsored b\ the Safety and Hygiene and the Plant and Plant Equipment Conimittees at the Fiftieth Annual Meeting of the Amer ican Foundrs men's Association at Cles-el.ied. Mas 6. mtG also serves as the exhaust fan for the system. Sprays arc located in a precleaner section and in the impeller unit. The entrained liquid and dust arc thrown against the impeller blades and the dust and water precipitated through a by-pass into a sludge hop per or tank. Usually the liquid is not recirculated but runs off through an overflow pipe from the' settling tank. Ordinarily a fresh water suppis is icquired. impingement Type Collector Impingement type eolleetor i Fig. 2: i- usually designed In direct air (low so ,ts to cicatc the desired water pattern and impinge the dust parti cles against wetted sm faces in one or more stages. The water is ndniilled near the top of the collectoi. just helms the moisture eliminators. It ili st ends against the air stream washing all tin suifaee and (aris ing the diisi downwaiil A -uimg lank mas he n-cil nr tin efllucnt mas he pumped or ill.mad to the disposal aica L'sua 11 s tin liquid is reciri ill.iled unless the effluent is taken directly to the disposal site. A small amount of make-up is required to compensate for evaporation and sludge han dling. Combination Types of Collectors In roinbinatiton tv|>r collectors fl'ic. A), the dust laden air is usu ally fust subjected to a sprav and then foiled through nozzles or bub ble caps so that the air passes through the liquid. Sometimes the liquid is treated with a wetting agent to form a foam bed through which thr air pa-ses. The dust then settles to a sludge tank In some designs the liquid is recirculated and in others drained off. Make-up irequired for evaporative and sludge handling losses. Foundry Applications. Most wet collectors have a relatively high effi ciency and are used for dust control of all foundry operations requiring collection including grindfng and cleaning room equipment. They are especially well adapted for handling air at a wide range of temperaturs-s and moistuie content as in the case of shakeout and sand conditioning operations. Collectors have the ad ditional opcialiug fc.ituies: 1--No file hazard present. 2-- No health hazard in handling the collected dust sjnec it is in the form of sludge. a -Constant resistance for a given system eliminating fluctuations in air volume. 4--Continuous operation is possi ble shut the t olln ted liilst is washed dow n i oust.mils to the set tling tank. Collector installations. Collector installations are varied to suit re quirements (Fig. 4 and 5). They range from a small completely selfcontained unit for an isolated opera tion to a complete foundry system involving a number of collectors. In larger projects a study should be made to determine the most econom ical arrangement consistent with flexibility of foundry operations, sat isfactory performance, and ease of maintenance. The tendency in our company has been to locate the col lectors as close to the dust pick-up points as practical and to use a cen tral dewatering system. !4 i ouurr Wit Tm: 'V - C> : : : ." OK Fiy 1 '.'Abort')--Dynamic precipitntm ixjn tuliidtn u ith scttUn" tank anti ihul'ji' ejcetoi. Ft; 2 , ZJi/(ire )--Cut atrar n'r.v of an mi pinncnit nt type milt ctor. ll'n'i) dcsctinlt iiyniinl the an jli.aiu liinhni'j till tin suifat'Cs and tuiiuirj An tin tt doteiiteaid. Fin. j' {Abort')--I'iV.-i of a com bination type toilet lor tt heie dustladen ah is subjected to a spray heated with a teettiun uncut /win. my a foam ihiounlt tehiih the ait passt j f Fatt ntt d). Fi". 5 t Aborc)--Colh rtoi outside of builditin Id aruttl loss of lout bin" spare. Fty. 4 (llelotr)--Cleaning loom collcctoi suppoilcd oriihcad to nroid loss ol teoil.in" Sparc. t 4 A. S- Li'm>y 'J'lii' ha- the advantage of saving - prci.tl attention .as. more huild-iin lecting eqiupi""::' rf'Miit! i> *ei> . ter power and reducing dun mainte iisttallv occur- there than in other that wii: give I'uuii'T : -uli- war nance Collector' should br located portions of the rollcrtor. A small minimum uuu.tl ,i:u; unk> cp co>'- 10 avoid using valuable - working amount of preventative maintenance Duc to variation' ai installations am1 'pare Thev may br located above vs ill. save a lot of time inter on present condition- r.o rvii.dui re-: the floor or those types having a (Fig. 7). intormaiion inn be given lor tom- separate ^ctiline tank may be placed Sludee Handling. In general the pletr w -tenis. outside without danger of freezing collected dust has little value and The ro-t m.iv mil 11 mu a levs provided the inlet air i< well above a freezing teinjvcraturc. can be readily transported to the disposal area. The method of han bundled dull.u- pm thousand elm of air handled m large sv'lcins to Collector operation In operating dling is influenced by sludge quan several bundled dollars per thou wet tv pc collectors care should be tity. relative location of settling tank sand for small -s-iem- For this rea takrn to follow the manufacturer's to dump, and transportation facili son dust pirk-up point- should hr instructions. Otherwise, inefficient ties available. The solids are re combined m a- large a svstem as performance and increased -wear moved from the tank by hand, grav possible without samlii mg llexihihtv i iii:iv result. There should be an ndc- ity, or conveyor or other mechanical of 'foundry operations. fpiatc supplv of water (Fig. 6). Ordmarih the water supply should be means. Equipment used for carrying the Summary interlocked with the fan motor to solids to the disposal site may range General types of wet lolleitois t prevent the collector from being operated dry. from a wheelbarrow to a railroad car. However, dump buckets arc and their application ami operation have been brieflv discussed. Their It often is advantageous to run most frequently used. It is some arc several variations from those w.nci through the collector a short times possible to eliminate most of mentioned and their installation and time after the exhaust system has the sludge handling by pumping the operation may have to be modified been shut off to flush the collector sludge from the settling tank to the accordingly. However, most wet and effluent lines vs hen used. The dump. Such a method should he type dust collecting equipment can rollcrtor should he inspected period laid out carefully to avoid plugging be installed with a minimum of in ical!',. prrhap' onrr a month. Mois the pipe. terference with foundry operations ture clmnn.Hors should he given C'- I'.quijtment St let lion. Dust col and vvill give satisfactory r*csults. w -r- _~ *- Fig. ft (Lch )-- Cnnrryot type ireiieulnliiig tank. Fie7 (Hehr.v)-- Bottom dump leeoeulntni^ tanks joi load- ing dnettly into tiuek or tailwod tat. i . r;elL : |-i k H fer h1 Prr-.ii-- .s . 1 M w \ |Wf <'*' fe r, u.-" i FANS AND EXHAUSTERS Philip Cohen District Manager B. F. Sturtev*n+ Division Wet*figKyie Elc<fic Corp. CleveUnd a The author defines tans and blowers. He dis cusses the centrifugal fan, squirrel cage type fan. radial blade or paddle wheel type fan and the non-overloading type fans. Design and selection of hoods and piping, dust collectors, and fans are interdependent. esearch .md development R w hich have brought fume and dust hoods, piping systems, dust collection and disposal, impor tant component parts of an air han dling system to their present high efficiencies involve much in the wav of time and expense. Full benefit of these developments cannot be re alized without thr use along with ihrm. of an equally efficient device which. ficuratively speaking, gives them life--just ns the heart does to the human machine with its veins nr ducts and its dust and waste col lectors. A well built human machine i> helpless without a good heart oi pump. Similailv. a well designed air handling system cannot produce it; potential benefits without it too l,a\me a rood "heart" w hirh we hair come to know in the foundry industry as a fan or blower The firsi use of a fan for collect in'.: and convrvin; dust was in )8fifi. The writer quotes from an article bv Mr F Burnham McLcars in the March 1914. issue of the U'oild U ni/: refeinne to this application as fo]losss: "Now this man Suiricvnnt was a Yankee and brimful of Winker brains. One mdustrs. it appears, did not satisfy him And so when his workmen complained that a shoe buffer he had made, stirred up a fearful rloud of dust. Mr. Sturtevant made a studv of the blower problem. I ll'- result is as a little exhaust fan which seated itself close to the buff- Piiscnnd at a Session sponsored bs ihe Safetv and H'etene and the Plant and Plant Equipment Committers at the Fifurih Annual Merlins of the Amrrlean Foundis mrn s Assoeiaiion at Cleve land. Mas 6, 1 P-t6 ing wheel and sucked away even,' particle of leather. The air was left clean as a whistle. Thus came into being the first satisfactory exhaust fan, and the father of all modern fans and blowers in use today." Fans Defined Tlie NAFM (National Associa tion of Fan Manufacturers) has rcccntlv issued Bulletin No. 105 en titled "Standards. Definitions and Terms in use by the Fan and Blower Industry." The author quotes from it as follows: "The term fans and blowns has ionic into general use by custom. Within the industry, the terms fans, blowns and rxhnnstns convey the lollowing ideas: 1 Fan' refer to the coniplctr as sembly of a machine comprising the lotor and housing and includes both blower' and exhausters. 2. Blowers arc fans used to foicr air under pressure. 3. Exhausters arc fans used to wtthdiaw air under suction. A centiifucral fan consists of a Ian rolor or wheel within a scroll i or spiral) Is pc of housin':, includin': diising mechanism supports either for belt drive nr direct connection." A eentrifucal fan is a centrifugal pump. It imparts energy to thr air passing through it hv the action of centrifugal force, drawing air in at the renter and discharging it at the periphery of the wheel into the housinc from which it passes out through the discharge opening or outlet. Despite being invisible* when clean, air has definite weight or mass; 13.33 cu. ft. of air measured at 70 F. and 29.92 in. Hg. (normal atmospheric pressure at sea levci) weigh 1 lb. This means that a fan handling 13.333 cfm. o actually working with a mass of 1000 lb. per min. or one ton even- 2 min. A mass equal to 1 ton of sand or 1 ton of iron passes through 30 times an hour in that particular size of fan. It is obvious, therefore, that n fan for use in a foundry must be a rugged piece of equipment. The measure of the total energy imparted to a quantity of air flowing through a fan. is the total-pressure which it develops. When that quan tity of air, or volume in cfm., passes through a fixed fan outlet opening, it must do so at n definite vclocitv since Velocity Quantity divid ed by Area. This vclocitv represents kinetic energy, the energy of motion, and is measured bv the velocity pressure which creates that motion. The difference between this veloc ity pressure and the total pressure generated by the fan is known as the static pressure. Velocity pressure acts only in the direction of air flow. Static pressure acts in all directions: at right angles to, and in the direc tion of. the air flow-. It is the pres sure which tends to burst or collapse a pipe or chamber. It represents jiotential energy. The writer likes to think of veloc ity and static pressures in a less technical sense. He likes to think of velocity pressure as the vehicle which speeds the air along. lie like* to think of static pressure, because it also acts in the direction of air flow, as the advance guard, the mo torcycle squad, which moves ahead of the speeding vehicle, brushing aside nil obstructions to give dear passage to the vehicle. Ftg. 1--Squirt el race or mnltibladc ly/ic fan. Imagine, if you will, that the in side surfaces of your air piping arc not smooth but instead covered with bumps and projections, bristles and obstructions. Imagine further that our invisible motorcycle squad moves ahead smoothing out these obstructions. The measure of the cncres with which this i done is the static pressure, lit short, it is the inter which overcomes resistance to the flow of air. It takes horsepower to develop nrc'smc. ObviousK. the slower the .in lias to move, the less velocitv |in"inr i- requited. The U ss resist ance there is to overcome, the less static pressure is required. Keeping these component part- of the total piessiue to a minimum, keeps the horsepower required to a minimum. Low air velocitv also means less uluasinn or erosion on elbows and ducts Lower total pressure means lower fan speeds and longer life. If tiie true tesistance of a svstcin is no moic than the static pressure lor winch a fan connected to it is selected, the cfm ratine of that fan ai that static pressure will actually flow thinu"h th' swiem piovided: 1 T hat the manufacturer's tables aie rated on NATM and ASHVE Stand.ii d' 2 'lliat restrictions or bends at the inlet or outlet, ospcciallv the former, do not chance the fan char.,et< ri-tir v% hieh is determined bv test with in diameters of straicht pipe on the inlet or outlet or both. a That additional connections from additional grindinc wheels, lumc hoods and dust collectors over and above the original .design arc not added ad infinitum without in creasing the oricmal speed and po`sibls the sire of motor. The writer 'cannot rniph.isirr too stroneh that a definitr relationship exists between the fan and the s\ -- tem to which it i' connected. Mans' engineers have the impression that when a fan is selected from the fan tables for a certain cfm. and static pressure and the fan is operated at 1 lie speed indicated, the fan will au tomatically deliver that amount of air. That is not necessarily so. A fan has an infinite numher of rapacities at a given speed. Imagine a fan in operation with no duct work on it and with merely a solid plate fastened to a short outlet extension. This is one extreme. We call this `Blocked Tight." The cfm. delivery is zero. The pressure developed is slightly less than the maximum pres- Ftit. 2--Mtillihlade forward rutted Itladr rotor for fan ill Fij. 1. sun- the fan can develop at that speed. It is railed the Static No Ilelivcn. It lias no practical value in the field. Thr oilier extreme is to remove the solid pl.itr and then we have the maximum c apacity of the fan at that speed. It is called the Wide Open Volume. Between these two extremes therr is an infinite number of capacities, and which one vou ob tain is wholly dependent upon the nature and magnitude of the re strictions placed on either the inlet side or discharge side of the fan. or both, in the form of hoods, piping, and collectors, rain caps. etc. A fan will do as much as it is permitted to do. It will operate unvuln'ir in II- cap.u it*, i.ie.e - ui," jrrt onb and (ompirinv id th" p sistanre of the -win;;, in mu": words, the actual static pic-up- io-- A fatiiiahlc mrreb sa - in r-iteci- "II tile static pre-me Ip-* >- mon titan ,v inches, then thr i.m will de liver the specified an qu.units am: only then." If the static pie--me lo-- p more, the rapacitv fall- ofi. ll it is less, the capacity increase- In me former ease vou find insufficient an movenirnt at your hoods and a -ruling of dust in the ducts due to too low a velocity. In thr second ease, in creased velocity is the re-ult and usually the horsepower increases With excessive velocity, cosion of elbows and piping is morr rapid and collector maintenance mav be in creased. Squirrel cage-type fan. There arc on the market three distinct types of centrifugal fan. One of the oldest is the multiblade forward curved blade fan. sometimes known as the squirrel cage type (Fig. 1 and 2). It usually has 60-64 blades fen single width single inlet, with or without the cup shaped depressions in the blades. It is primarily a ventilating fan for low static pressures, not a fan for dust collecting systems. It occupies a minimum of space for a given duty and runs at the slowest speed. On the other hand, it has a rap idly rising horsepower characteristic and can easily overload a motor by a reduction in static prrssuir or hv adding additional connections. The curved dished hlade- make good re ceptacles for dirt and mutk. The Ft;, it -- Radial blade nt ftaddle wheel type of fan. ;18 F W> \\n I.\ i; U Ml KS Fry. 5--Dmyi nnmtntir tkrlrh nf Inn m Fry. 3. with fnnrisinn jar roniniy shn/1. writer feels this fan has no place in a foundry with the possible excep tion of the ventilating or a it condi tioning system for the office section whete the pressure requirements arc low and the air relatively dean. Rniiml hlndr nr /inddlr nhitl ty/ir Inn. The second tvpc i' the radial Made or paddle wheel t\pe `Fit; a!. This i- the old reliable of the indtis- trs It is unis an industrial fail. Til'- wheel i- made with 6 or fi sim ple broad Hal blades with oi without side plate-, depending nit the natiiir of the niatrii.il in the air stream 'Tie I It has hi on mn-r coni- iiionls mi d fnt dust lollciime ssork handling cxhaii't horn grinding. hu /Tm:: and jioiplnn^ u I', is iib Ml w iih on! riii-t ( ollretoV'. and be- foi e and alir i riti't ( o||r( toi- . ii'ii.ilb 111 1 .IP.1I JPf ' III) IO 2 1 nil! 1 ( fm. These (ail' ai a obtainable for l.ugei ( a pat iU<" 1)111 till N !>*( niiif l>nlk\ ; iiid nil) i-u 'pit (N m.ikin'j !o 1 ( O'l Is / - Rmi iii fuh )ti!m l"i Inn te Fry dm lie.' e(|iiipincnl J ltesc fait' arc alo (oiiunotilv ii'CC in core oven ssork and heat treating for recticulauon and ex haust. handling high trnipcr.nuie air. Thev can he provided with heat radiating devices to protect the hearings without the ti'C of water cooling. i Fit:, a). Flic paddle wheel design lends it self ven well to fabrication from heat resisting alloy sheet steel or to one piece castings of heat resisting allow for thai application. The pressure characteristic is more stable llian that of thr squirrel cage type and the horsepower does not increase so rapidly with a de crease in sweiii resistance. The pad dle wheel fan can well be railed the Fig. 7 -- Rnlnt ait/i 12 Innnd I'nrlunrdly rtirhnrd hindts Ini Inn m Fig. C. "Id tellable n| the llldllstrv \ nn-n; , ihurdiny /V/', Inn. T he thud is | >> i- 'hr niiii-m reloading is pe l.m has mg a wheel ssith ahoul 12-lb binud blade- foi 'ingle width, 'ingle inlet, birkwardls inclined mas limn tlte direction of rotation i ig f>.. While thi' fan w the nrssC'l of tlu-'c thiee tvpes. the first commeii tails -ui cr"ful d> sign ol liaikwaidls nit lined blades was at- lu.ilb m.i dr )ti ion. 1 be fan Ii;i' mans desirable fea tures. ft ha- a 'teep stable pressure t h.irartiTi'tic over a wide range of t.ip.-uits It j- the clo't-st approach to a constant volume centrifugal fan. An increase m system resist ance eanses less capacity reduction than in other tvpes. Jt has a self-limiting horsepower characteristic. A decrease in ss'trm resistance will not overload the mo tor since the fan has a predeter mined maximum hniscpowrr for every speed. Of the three tsprs. this one has the highest efficiency. It runs at high rotative speed' which permit' the use of smaller diameter V-helt sheaves with a high horsepower rating per belt. It lend' In direct connection to standard A. G. motors. If the non-ns reloading f.m has a ssiieel with flat, tatltcr than curved, hackwatdlv inclined blades (Fig. 71. it can lie used 'tia ("lulls foi han dling tltt't laden air. particularly in (.i|i.i( it it-' alios c 2.1.1100 rfm w here it tan 'boss an apprrt i.ihlc savings m hoi sepower. The flat blade i' self-cleaning and the wind will remain romparalivcis fiee from ans deposit' on the blades. 1 here i' no question about its use on the leasing side of an efficient dust collector It' use without dust collector' for drs shakeout exhaust and fume exhaust cannot be given blanket approval ;i' it i' s\) oils de pendent on the possibilities present for erosion and corrosion. I lowevcr. it' favorable rharaeteristu s defmiteIs warrant first consideration. All centrifugal fails can be fur nished in NAF.M Arrangement No. 1 and No. 2 whete the wheel is over hung. with both hearing' on the drive side and ssith a clear inlet. They can also lie furnished in NAF.M Arrangement No. " ssliicli has the svhccl supported between P Coiii:n F.'C 8--Axial flow ty/ir fan. bearings with one bearing in the fan inlet on a single inlet fan GencralK speaking, ball bearings with bust seals arc best suitable for femndrs installations. More thought should be given to tin u-c of Arrangement No. 3 ex cept m the rase of heavy dust load* mg>. aim or corrosive fumes, and hot gases. In these ease' the cantili ut Aitaiigrimnt No. 1 is unavoid* .ibii but careful attention must be ;nu; to Inundations and setting of the i umpnienl. It i' not reasonable to remit that overhung wheel fans ..tie e.nert (onnected fans particu lar;'.. r.m be taken from a freight tar and placed on a foundation without further examination. This : j):; I rat in mint be (becked fur level and aiicninent bm, i tin u a!. tin a r has been a in ab il inn ri -i in 11ii' axi.iI Ikiu fan. I tin 11, e tin w . 11 -i i t M It i nl 11 mi I a in n i m 11 ni n d Im Nan i iinthai m-s. ' ' '.i tii and mi d for hull \ enlil.iII *11 . ii placing eailier design' of lioi' i;. heavier renlrifue.il fans. In addition the N.iv\ ptocuicd mam moil lor forced draft boiler applica tion- devi inpmg pressure up to 60 ui 1 lm Ian will dcfmitek find a pi.a in loumln woik It ran ca.siiv be iiuiii fm the rapacities and pres'iin sou reijuire in dint lolleitmg hoik, although at pie-ent i ommer- 1^ rinI offerings air limited largcls to l1* to 3 iit. pressme. h is most prarticnl when direet connected to tin- motor The problem of keeping bearings and V-bc!t drives out of the an stream in belt driven units n not 'crious and lias been worked out. The axial flow fan should not be ued indiscriminately, although it is suitable for certain fume exhaust work involving large volume of air. The author used the axial flow fan for that purpose for the past five years and believes it is the fan of the future. Poor maintenance, addition of more connections without changing speeds and motors, are responsible only in a small measure for unsatis factory performance of fume and dust collecting systems. By far and large, it is because of divided responsibilitv for the installation itself. The writer tried to point out how interdependent the design and selec tion of hoods and piping, dust col lectors, and fans are. The practice of purchasing these items individ ually at minimum cost, together with the unwillingness of the pur chaser to pay for an extremely im portant intangible, namely, /'tigtnriinin Responsibility, is the reason for unsatisfactory installations even when utilizing the beM equipment available. Do not think in term- of ilmt and fume collecting look m iriiii- o: do-', ami limn i on-, tine lyi/i-tin Plan lie it.nir u -oon-ibi its at one 'nunc Coiiii.ir'. io: tin enure -wnn with one m or. installed and sate factors r peratutg ba-iv Whether tin- roiui.u na hi .. l.ibrir.uoi. ciii-1 i ollermr tn.,iiulai- i ut ft oi fan in.ii'iti.ii tmei. nheilier he maiiuiartuie- I" pri mu oi P0 per cent of the rontiart m.aerial in hw own shop', e not of pumc im portance. The ntipot taut thing i> that this contractor be finanrialK re sponsible and. above all. possess an engineering staff with the engmeet- ing "know how." For evert- cu ft of air exhausted from a building another cu. ft. will leak in to replace it. No building can be made airtight. In the winter time this can create a hazardous, cold, drafty condition. Do not in stall a dust or fume exhaust system without giving equal con'idcraiion to the replacement of that air through a properly designed tem pered air supply system. Granted these investments t cap ital equipment are costly, but the day is gone when they can be avoided. State laws have seen to that. But. in addition, efficient fume and dust collecting systems contribute definitely to increasing morale and pioduction. Obviouslv, therefore, they merit your most care ful consideration. Fty b-- / In-blnrir hylit tin tv m/ni fn fan in F.q H. Fi'j. W--Multibladr liiarv duty tutor /or fun in Fiy 8. MAINTENANCE OF FOUNDRY DUST CONTROL EQUIPMENT Kenneth M. Smith Foundry Engineer Catt'piH*' Trtctor Co. Peorit, lliinoil O EQUIPMENT is better N than the care it receives. The writer says "care'' of equipment because maintenance of equipment as commonly understood is too frequently undertaken only when the equipment has failed. Routine preventive maintenance or "urc" is nra-'vin if undesirable in to ruptioi)' ol service are to be avoided. Routine lubrication, cleaning, re placement of worn parts, and gen eral vimal cheeks of all dint control equipment will forestall the major part of equipment breakdowns dur ing production operations. Preven tive maintenance pavs bv eliminat ing a larce part of the losses ini lined vs ben wothers and equipment cannot be utilised while essential tquipment i- being lepaired. Exhaust Hood mid Duel Maintetumci Fotmdrv dust control starts with the dut hood and ducts. Once a hood and duet system has been vet up properly, even effort should he made to keep it in first class con dition. Hood inlet adjustments must he maintained, and dirt accumula tions must be removed legularly to provide proper ventilation volume. Figure 1 shows a tv picul dirt ac cumulation in a hood entrance. Dirt accumulations should also be re moved to promote the good house keeping essential to the modern foundry. Not only do dirt accumulations in hood entrances and duets cut down the volume of ventilation available, but they frequently constitute a dan gerous fire hazard especially where core oil fumes condense and soak into the dust accumulations. Where such fire hazards exist, steam jets should be installed in the duct sys tem ahead of the fan for use in smothering a fire. Opposed steam jets arc necessary to prevent the jet acting as a duct inspirator as well as to fill all sec tions of duct with steam as quickly as possible. The stop button for the fan should be iiwt.illed by the steam jet valve. The steam jets should be turned on for a few seconds at regu lar intervals to insure their proper functioning in emergencies. Liquids which condense in ducts should he continuously drained out into containers which should be emptied frequently. Figure 2 shows a duct drain and collecting con tainer for eore oil residues and water ftotn a mold eooling tunnel exhaust 4 Routine preventive mainte^ nance or care of foundry dust control equipment is neces sary if undesirable interruptions of service are to be avoided. The writer goes into some de tail discussing maintenance of fans, cloth type dust collectors, rotary centrifugal collectors, wet collectors, and air filter type collectors. Proper dust control equipment maintenance consists of good routine care and inspection plus replacement of worn parts before equipment failure occurs. duel. Figure j shows the fan section of a similar duet which is badlv in need of cleaning. Also the duct en trance door needs a drip deflector on its bottom inside edge. Frequently dust control hoods are severely abused and rendered use less especially at shakeout.. Hood face parts must be rugged. Where experience shows .that hoods will be abused, construct them of heavy materials. When long horizontal ducts arc used to convey dirty air to a dust collector, they should be made in flanged sections bolted together to permit turning the duct to a new position several times in the life of the duct. Otherwise, the abrasive wear on the bottom of the duct will cause premature duct failure. Bolted flanged elbows in abrasive dust sys tems are useful for expediting quick replacement of worn nut elbows. All hood- on grinders should he kept clean and in fust-class repair for safety and dust control Fan Maintenance. Since the maintenance necessary on a fan is very frequently determined by its design, the proper fan for ihc dust and fumes to be handled must be chosen with care. For exhaust sys tems on mold pouring and cooling stations, core ovens, or unv system handling condensible fumes, radial blade centrifugal fans will give the most s.iti'factorv results sircc they are relatively self cleaning by cen trifugal force. Figure 4 shows an example of a straight radial blade centrifugal fan itnpcllor in contrast to the multiblade type of fan im peller shown in Fig. 5. If a mullihladc type of fan gives K M Smith O Fig Stimuli: ludtul hiadi I an tin t'< tlo, /-- 7 ypira! tint rit cumulation at exhaust hood inlets above mold pounng station. Fr_ ?-Ducl chant unt! coiltiliii" , i.i i ioi ilnil handlin i onilcn- >;bh lumen z- -...^.. - '^ *n v-"- ic> ~y p-yi F/;'. 7--Duel anil fan handling con(Fusible fumes ftom a mold pounng nation show.tig nrrrnitv jot petiodic eh ailing. Fig. 5--Multibladr type fan ini pellor. II fm I -] ; --I Fig. 9--Fan dm- niDSing. on. lull Fig 6--Multiblade type fan impeller on mold break apart zone exhaust bearings should be kept well lubri hood showing necessity for regular cleaning. cated especially in ducts fiom mold pouring exhaust hoods which may carry hot gases. Figure 8 also shows continual trouble from dirt build up down the blade area which can col an easily adjusted licit: tightener for ,:ud consequent vibration, it should lect dirt. Even so. they should be duct fan drives. The drives for cen In irjil.aid with a fan of the radial cleaned regularly. Convenient access trifugal fans which me multiple V- Marie npe I'i"mi- f) 'lum> a mulli- doors should be piovided in the hells are ollen abused, Ficquentlv huali t\pe fan impellor on a large duets (Fig. 8) to permit easy cloan- the individual loose or broken V-belt mold Iiii ah apart exhaust system inc and changing of fan blades. is not leplaied until the o\ erload while ueulai i leaning of the fan The belts on external diive duct on the irm.lining hells has damaged mini lloi is m ct 'sia Cleaning and fail' must be kept debt, and the them loo See Fig. d. i in ikiiie uf 'Ut_h Ians i an be done moii easii\ if a 'icuon of the Ian m loll 'heel is madr renui\ able. Suit..!iil si aline sinp. 11mst he provided Fig. S--Piojnlloi type fan with amph duet enhance dinii and eonnement belt tighteuniit a> untili "ti nt. oi. e(iei ' ol the lejnovalile sec 1:011. When \ ibini.1011 n drteeicd in a ii n: 11! nea 1 : an. :l should b. i liei bed I oi mmi ol ni-'-me unprlloi blades .ml I oi i: i.i lei la! a i i II11 n ilaml i - on I ie 111 ii j i .oi \ 1 a ti i lal at i u 11 lula- II 'ii' 'i......it! i ii iniiiiirii ant I net O'- all I t pa I I - I I la til 1 ;e III I I show s . I i I pa 11 t! I a I i I III 111' I lol . Kl I till It fail 11: ipi I ioi -bould hi I .11 el ulh bal- a:11 t cj \ ii n aiit <ii build up in a cen[ I 1t 11" .; 1 1 , i an lie ea'ih deli (ted w ill'll rile bt .inn"' are given their 1 ( uitnu I uij I K .iiinii Centrifugal fans 'i loiild no l he ,,| lerated at high '1 >rvtU uni < ' tliev aie given verv *od < .lie \ llw atii m fiom dnt\ im- 1 H llul. n *i llg at high speed tan l . lllM' ' 1 T'l i li ' d.iui.i ge. On titisi and twine ct'iilrol systems w lieu tin dust is not cnllectcd, propellor t'pe fans aic ficquentlv used. When thex arc used lo handle rondensihle fiiine-. thm should be of the n.mtni : i.i::iii:ii blade t\ pe to eut K M Smith < a^gsv:-." ' 9v. F/g. //--Dust collector bags showms ne:r has and well warn bag with dm accumulation. iI Where abrasive dusts may be en countered. t lie propcllor blades uiii-i In- checked and changed in i lodicalh to insure efficient fan performance. Figure 10 shows typ ical worn propeller blades which need chancin'.' in order to insure efficient \ entiiation. Note the main tenance man'' quick method of ob- t.ii.-iinc an ndeijuau- door for fan Made 11-placement. doth V't/'i Collcctoi Maintr- Fig. 12--II om itnpcllor jot rotary centrifugal dust collector as crated for return to manufacturer for rebinding. Si-\et.il i\n-' ol dust rnller- tot- are awed in the foundry, cacli havint; separate maintenance prob lems. Where there arc no condensi Iho hind, - on Ian handling air containing abiasrcc dust. ble fumes, high temperatures, or gummy material' present, the cloth type collector is commonly used. Both the tube and the envelope type bag will eventually increase in resistance from the accumulation of lint in the cloth pores. This lint ohen mines from grinders' gloves .md fioin paper used to clean safety glasses. When the cloth resistance increases sharpie, the bags should be replaced. Otherw ise, ventilation vol ume drops and rapping device' neat holes in hags which in turn lets the - - - cV'.` - -r-- abrasive dust wear out the fan. - i -`l F.vcn if lint doc' not get into the cloth pores, the mechanical cleaning will wear out the hags in approxi mately two wars of twenty-four hours daily service. Figure 11 shows a worn bae m eonlia't to a new hag. Continued rapping has worn the old bag thin enough to permit dust to pass through in a few areas. Rapping devices should he kept in good order to keep the collector hags 24 oen-rr \ jeoHiJ ij ____________ iTW Bi Fty. 13--Multutape ;ret ci ntnfupa! riu'! eollectoi siiomn; points tchere deposits may build up. in full me Cloth collectors should hr shaken down nt regular intervals such ,1- lunch linin' nnd nl shift i hnnc1' with f:m nmirri nfT. The (ollrrtrd material Imppris should hr emptied rccul.u lv m prevent unnrrr",u\ dii'l rrnrrul.ilmn against ihr rlolh 'nek'. The dim .nil inlrt iiniM he kept h.nfllecl to proven' the air stream from impinging (iircctlv upon ihr rollcclnr '.nek'. 1\ n t n i Cent iiiu^al Cnlh , tin Mamit limit . I he rnl.ir\ icntiifuC.il l\pr of (dllnioi ciiinhmo col lector nnd fan function-.. lor light dii'l loud' ihr\ will npciate for lone period' with onh miilinr luhruatioii and cenrrnl ni'pei non. Foi heave ahiasivr dii'l load' the lotarn erniiifncal fan collector should he proi idrd w ith liner'. These liners should he cheeked peviodirnlh to prevent excessive danince to the main eollcctnr housinc in rase the Imrrs wear through. B\ the time a set of liners lias worn through, the fan nnpellor probable will need rcblndinc. Prompt rebind ing sen ier is piovided bv the inaimfaeuner of this rtjuipineiT*. Maintenance o>r Forsnsv ])v>: On-.r.-i . ::>!> nt Fictire 12 shows a wont inipellor crated for rrtum to ihr manufarturei for rebinding. For heavy dirt concentrations, a prerlrnner arrange- inent reriurcs the "car on the fan inipellor and housing. The dust hopper for the rotary centrifugal collector should prevent any recircu lation of the dust. Empty the hop per at frequent intervals. JFrf Collector Maintenance. There are several wet type dust col lector arrangements available for foundry use. Their basic principle of operation is to mix the dirty air with a water fog or spray in order to wash the air. Some form of mois ture elimination is then employed to separate the water and dirt mix ture from the air stream. If rotary impellors arc used, the impellors must be kept clean to prevent vibra tion. If baffles only arc used, thev should be cheeked periodically. The eliminators must be kept in good order to prevent extra carry over to the fan which may get out of balance from solids built up on the inipellor. Where a mechanical sludge conveyor is used, the con veyor will need routine checking and occasional repair and replacement. Do not put core oil fumes through a wet type rotary centrifugal rollertor. Thr fmnrs condense on the fan impellor, where llww rolled dirt, ami throw the nnpellor out of halanre. Where a serie' of vertical centrifu gal eollerio? 'ciiioi!. ,i, .we, m a wet rollertoi. ..ri'iiu.t v t "V'1 must be ]1.-I"rd linnngh lie' iniji-, to. to keep it fiusiirrl rlear. I: tlv- warn inu*t be recirculated. adeem.m- set tling tanks oi basins inn; be )!sided. Dirts' water deposit- -lndcr in the collector sections. as shown in Fig. 13 It al-o plug' thr water lines nnd the d:am. and wears out the circulating pump Dirt also tends to collect at the collet tor inict as shosvn in Fig. 13 Tim dirt must be removed at regular intcixals from both the collector sections nnd inict. Provide adequate clean water, and this cleaning problem will be re duced to the occasional cleaning of the collector inlet. Air Filtei Type Collcetoi Mainte nance. Figure 14 shosv? a grinding bench equipped with six sectional type air filters. These filters arc rcmos-cd every second dav. cleaned in oleum, sprased svith SAE 10 luhricrating oil. and reinstalled. This maintenance is done on th^ night shift when the grinding benches arc not in use. but a spare set of filters w ith the portable dipping and drain ing equipment would make it possi ble to do this work at ain time. Summary Proper dml control equipment maintenance consists of good routine care and inspection plus irplai riiienl of worn parts lirfnir equipment (ailurc os cui' HEALTH PROTECTION IN FOUNDRY PRACTICE Papers presented at a Conference on Health Protection in Foundry Practice at the Uni versity of Michigan School of Public Health, April 1 1 and 12, 1952 in Ann Arbor, Mich, in collaboration with The Michigan Depart ment of Health, Detroit City Department of Health, The Institute of Industrial Health, The Department of Production Engineering and the American Foundrymen's Society. AMERICAN FOUNDRYMEN'S SOCIETY CHICAGO '>T.1- U>4W'1ilU./ *JJ"W, 7 -1--1 mj TABLE OF CONTENTS Page The Foundry is a Good Place to Work - by A.C. Hensel....................................................... 1 Nature of Disease Caused by Dust - by O. A. Sander................................................................ Measurement of Dust in Foundries - by D. E. Van Farowe................................................... 1 Control of Dust Housekeeping - by H. J. Weber.................................................................................................................. 25 Isolation, Substitution and Wetting Agents - by Edward Meiter.......................................... 35 Resoirators - by A. J. Kaimala ................................................................................................................... 41 Ventilation Principles - by Wm. N. Withendge.......................................................................... 48 Problems of Ferrous Foundry Practice Sand Handling - by R.H. Moore.................................................................................................................. 56 Coremaking and Molding - by G. E. Tubich....................................................................................... bS Metal Melting and Pouring - by J. C. Radcliffe.............................................................................. 77 Shake-out and Core Knockout - by John Kane................................................................................... 83 Casting Cleaning - by W.W. Dodge......................................... ............................................................... 97 casting Grinding - by K. E. Robinson.................................................................................................... 119 Problems of Non-Ferrous Foundry Practice 'iture, Manifestations, and Medical Management of Lead Poisoning and Metal Fume Fever - by L. E. Hamlin........................................................... 126 ''-asurement of Lead and Zinc Exposures In Air, Blood in Urine and Porphyrins m Urine - Wm. G. Frederick....................................................................................137 n[rol of Metal Melting and Pouring Operations - by G. M. Hama............................140 tro1 Nonferrous Foundry Dust Exposures - by B. D. Bloomfield.................. 149 V< cellaneous Exposures in Foundries - by C. P. McCord...................................................165 V and Health Program Pays Dividends - by W.G. Ferrell..................................... 169 MEASUREMENT OF DUST IN FOUNDRIES by Donald E. VanFarowe* Health hazards associated with the use of silica dusts have been recog nized since shortly after the birth of Christ. In the time of Selier II a disease Known as ''knife-grinders disease" was prevalent. Today we call it silicosis. During Hero's day men working in mines often covered their faces with transparent animal bladders to protect themselves from the "pernicious dusts". You may well ask the question then, if man has known about the effects resulting from the inhalation of silica dust for this many years, why hasn't more been done to prevent silicosis lone aco1 The answer may be given in part by the change is social organization since those days long ago in Egypt, Greece, and Rome. They, of course, had the "slave". If he became ill and died, they just bought another slave. Maybe the slaves felt that death or severe illness was a relief from the burdens too heavy to be borne. Medie val Europe was little better. The Lord of the Manor cared little about ills and woes of his subjects. Since 1SOO man's attitude to man has been changing. Today we have lost the cast system, of society. Today, our fathers, our urothers, our uncles and our cousins are working in a more scientific industry. This change has become evident by laws regulating conditions of employment, including Workmen's Compensation and Health Laws. Dust is now classified as a hazard in industry for which the employer is liable. Physicians, chemists, and engineers have worked together in organiza tions such as health departments, universities and private research foundations to help the employer m dusty industries such as foundries to make a safe working place tor his employees. The definition of dust given by Webster is "a fine dry pulverized particle of earth or other matter." The vast majority of dust in the air is below 10 microns in size. Most of is even below Z microns. It has a settling rate below 1 centimeter per second, ar`-> therefore, is easily transported by the smallest air currents. In a sense it constitutes a part of the air itself and goes wherever it goes. The measurement of the dust in the foundry requires two steps: 1. Sampling the dust, which must be removed from a represen tative volume of air and concentrated so that a quantitative study is possible and Z. Analysis, which requires the determination of the amount and kind of dust in the sample. Chief Chemist, Division of Industrial Health, Michigan Department of ' 'ualth, Lansing, Michigan 11 The d eve lopme n' of silicosis in most cases is a long range process \ .1 : from 5 to 20 years. Sampling may be a matter of 8 to 10 hours. It is obvious the problem requires statistical interpretation. In order to get a reasonable rr> c a 1: ment of the dust exposure, one must sample the locations and variations o: dusty opi r ations -- so-called dust floods and also average room concentrations. No detinue pattern can be outlined since conditions and practical limitations will varv trom one problem to another. The industrial hygienist must rely on his experience and ho' s_-- sense. Instrumentation for Sampling Dust collecting instruments may be divided into two groups according to the volume of air sampled: 1. Grab samples - instruments which sample a small amount of air in a few- seconds., 2. Continuous flow rate - instruments which collect an integrated type of sample. Each type of instrument has its merits. If one wishes to locate the source of dustiness, the grab sample method is ideal. In determining a health hazard, the grab sample method should never be used alone but may be used in conjunction with an integrating type dust collector. , Dust sampling instruments may again be divided into groups according to the method of collection: Impingement, filtration, electrostatic precipitation, and thermo precipitation. Sometimes it is necessary to use one or more of the above methods for measurement of atmospheric dust. The specific purpose for which the samples are to be used will determine the method of collection. Im pi n ge r The acceptable standard technique in the United States utilizes the Greenburg-Smith Impinger (Fig. I). It is a device through which the air is drawn at a given rate. It has a small orifice winch causes the air to travel at a high velocity making the dust particles m the air stream impinge upon the small glass plate below this orifice, due to their kinetic energy. The nozzle velocity is an important factor in the efficiency of the collection of the impinger. A suitable liquid is placed in the flask so that these particles are wetted and then suspended in the liquid (Fig. 2). The air is drawn through this device by means of a suction pump. The a mount of air is determined by a calibrated device on the pump so that the amount of air which has been drawn through the impinger may be determined (Fig. 3). Fart of this liquid medium is then placed in a dust counting cell under a microscope and the number of particles counted in 1 cubic millimeter of the liquid (Fig. 4). When you look through the microscope ocular a dust count will look like this. The larpe square is 1/4 of a millimeter and each small square is 100 microns in size. These dust particles, as you can see, vary greatly in size from the largest to the smallest and also vary in transparency and shape, which can help to identify certain types of dust. 12 44' - ,u-c 5 shows another dust field and also a large dust particle. After several of ' f samples have been counted to determine the average count, a-multiplication - or can then be used to determine the number of particles in the liquid in the Since we already know the amount of air we have drawn through the impinge: niay calculate the number of particles in the air sampled. r.c-rtrostalic Precipitator The air passes into the tube between two high potential electrodes as shown Tip- 6. The particles are collected on the inside wall of the tube. Two forces ,-iuse precipitation: 1, The ionic bombardment of the electric wind created by the corona discharge, and 2. The attraction of the charged particle to an oppositely charged plate. The efficiency of this instrument is high for metal fumes and certain other -elected materials. It is used principally for total weight and chemical analysis. However, it may be used for dust counting, provided certain conditions exist which u'.ll permit the use of this type of instrument. Thermo Precipitator 1 am sure that you have seen the principle of thermo precipitation in your Tomes or in offices, where a warm air stream laden with dust particles passes near o cold surface. The particles will precipitate out and cause dirty streaks on the wails. This same principle is applied in the thermo precipitator instrument. The a: r is heated by use of a hot wire and then passes over cooled surfaces, usually glass slides upon which the dust is collected. The thermo precipitator has a high efficiency in the 0.2 to 20-micron size This instrument is used principally for dust counts and particle size. The reliability of the instrument for dust counting purposes is poor. The sample that is oliec'.ed is too small for chemical analysis; therefore, the instrument is seldom used for this purpose. Komme t e r* The Kommeter (Fig. 7) employs the impingement principle and is classi fied as a grab sample instrument, since only 5 cc of air are sampled. The dust is impinged on a disk which has been covered with mineral oil or petroleum jelly. This instrument can be used for dust counts and particle sizes only. Samples for chemi cal analysis and gravimetric analysis cannot be collected by this method. The efficiency of the kommeter is low and is selective with respect to par cte size. However, it is probably the most convenient instrument for dust count- 13 ing available. Samples can be collected with speed. The konimeter should be used as relative indication of dustiness in conjunction with the impinger. This instrument has been used largely in Canadian and South African mines, where silicosis has beer, re duced and controlled successfully through its use. Filtration Filtration has been used widely as a means of collecting dust from gases (Fig. 8). In general there are two types of filtering materials used: 1 . Insoluble, and 2. Soluble. Insoluble includes filter paper, cotton batten, earthen wares, and cloth. Soluble filters include sugar, resorcinal, anthracene, etc. When samples are collected in this manner, the results may be reported in either percentage by weight or weight per volume. A method of measuring the amount of air flow and a source of suction must be provided. The efficiency of the filtration method is largely depended upon the type of filtering material used and the particle size of the dust to be collected. Summary of Instruments In order to select the instrument suitable for the job, certain factors are taken into consideration: 1 . Portability 2. Amount of sample required for analysis. 3. Reliability 4. Reproducibility of collection 5. Cost b. Time ' Physical and chemical properties of atmospheric dust. There arc limitations in instrumentation. Failure to recognize this fact would be unwise. One goal must be kept in mind -- that is to reduce silicosis. Measurement of Dust Concentration Samples for dust measurement may be taken under three conditions: Moving particles in moving air, such as the duct system. Pa r - 14 tide size distribution may vary greatly over a c ros^-secttdnal- area of duct-work due to air turbulence. It is obvious that- sampling1 should take place in a location which is at least 7-10 diameter from the last elbow, restriction, etc., then using the traverse technique for taking a sample. 2. Still air -- general atmosphere. As mentioned earlier in the paper, the particle size of air-borne dust is 10 microns and below. This dust may be considered as part of the air itself. We know that the average man breathes about 10 cubic meters of air in an S-hour day. Our job is to get a representative sample of the air that he breathes to evaluate the amount of dust in it, and its chemi cal analysis. The standard Greeriburg-Smith Impinger, the elec trostatic precipitator, and the thermo precipitator are examples of the type of sampling apparatus for this type of measurement. 3. Material sample -- settled dust or parent material. Per centage analysis on a sample of this type does not mean that the constituents appear in the same percentage in the air-borne dust caused by the parent material. An illustration in point may be as follows: Suppose you are breaking a rock wall with a sledge hammer. This can be a dusty operation. If you are to take a sample of the rock and of the mortar in proportion as it is in the wall and do an analysis on it, you would find about 10 per cent mortar. However, if you were to analyze the dust which was raised by this operation you would find that perhaps 95 per cent of the dust was from the mortar. The same situation prevails in dust analysis in foundries, so care must be taken with interpretation of analyses of this type. Units in Measurement of Oust Concentrations The concentration of dust may be measured in terms of counts per unit volume or weight per unit volume. Each has its purpose. The gravimetric method has the advantage over the counting technique in that it is most reproducible. Count ing is subject to great variations depending on the skill, fatigue and inherent visual perceptibility. These variations can be minimized only by experience and training in industrial hygiene. The advantage of the counting technique is that the effect of the silicosis or. the lung is a chemical reaction and, therefore, the number of particles, rather than the weight is the determining factor, since the amount of chemical activi ty is the function of the surface area exposed to body fluids. Another advantage of the counting system is that low concentrations may oc- counted while it would be impossible to weigh such small amounts with any degree c: accuracy on an ordinary analytical balance. Sometimes it is advantageous to es tablish a relationship between count and weight. This relationship should be estab lished m each individual type of operation and dust. A practical figure which can be used for quartz is 1 milligram of dust equals about 300 million particles as deter mined by the light field impinger counting technique. Particle Sizf Measurement Whenever one sets about to measure something, there has to be a scale or unit. For dust measurement, we use the micron. It is about 1/25000 of ar. inch. In other words, if you take a ball about 1 in. in diameter and let that represent the dust particle which is 1 micron in size, an inch would be nearly a half mile. Example: If a piece of quartz one centimeter cubed were divided into 1 cubic micron particles, you would have 1 million million particles. As mentioned previously in this paper, the chemical activity is a function of the surface area exposed to the body fluids; it would increase in this case from 6 square centimeters to 64.6 square feet or the size of an 8 x 8 rug. Also the million million cubic micron particles of quartz would constitute the maximum allow able concentration in a room 100 ft x 100 ft with a 20 ft ceiling. When samples are collected in an impinger, particle sizes as high as 50 microns may be found. Man has been equipped by nature with a filter system in his upper respiratory tract which filters out particles larger than 10 microns. Particles usually not larger than 5 microns will get down into the lungs. We are, therefore, most interested in the dust below 5 microns. In the last several years particle size has become a target of concentrated study since many investigators feel that it is the particle size below 1 micron which is important in many of our respiratory diseases. ft Methods of Measurement The linear sizing of dust particles may be accomplished in three ways: 1. By comparison with a scale which is incorporated in the ocular of the microscope. 2. By projection in measurement of the particle on a suitable scale. 3. Size classification for dust may be accomplished by putting it into a liquid and allowing it to settle (Fig. 9). The larger parti cles will settle first and the smaller ones will remain- suspended in the liquid for a period of time. This is a good method for a rough separation of coarse dust from the respirable size. Composition of the dust in the Respirable Size The analysis of dust for free silica in the respirable range is generally accomplished in one of several ways: 1. Chemical analysis 2. X-ray diffraction 3. X-ray spectrometry 4. Petrography 16 It would be of httle value in describing these methods in detail. The -method we use at the Michigan Department of Health is the x-rav spectrometer, v. rich you see in Fig. 10. It is composed of several parts: the goniometer, the cjaler, the recorder and the x-ray source. Sample preparation for this instrument is an exacting process, depending jDon the type of sample in which we are to determine the amount of free silica. The amplcs may come in chunks of rock or loose dust which has been collected on the -ross air sampler which you saw previously. If the sample is in the form of rock, has to be ground by the grinder, as you see in Fig. 11. After this process it is .--ound even more by a power pestle and mortar until it will pass through a very fine career. (Fig. 12). The sample is then a very fine powder with a maximum size of atjout 43 microns. It is then placed into a metal lozenge as you see in Fig. 13. Here you see a closer view of the x-ray source and the goniometer. The x-rays pass through the slit optical system, strike the sample and are reflected up nrough the slit system to the Geiger Tube. The impulse from the Geiger Tube is sent to the scaler where it is counted. The number of counts are registered on the recorder. The Geiger Tube and the sample rotate so that the amount of x-ray that reflects off the sample at various angles may be recorded (Fig. 14). The results of -he quartz, sample are shown in Fig. 14. Tne ratio of the length of the quartz lines as compared to the length of the line of the internal standard is determined. With this figure, we use a chart as shown in Fig. 15 to get the percentage of quartz. This is the ans*cr to our analysis. Accuracy of Dust Determination The purpose of dust sampling is not to measure the absolute dust concen trations but it is an index of the dust concentration. The requirements are physio logical consideration. The dust concentration is adequate to measure silicosisoroduemg potentialities of dust concentration in the air provided the results are rep roducible and proportional. An idea of the accuracy of.dust measurement may be received when we think of how the standard of permissible quantitites of dust have been established. Medical examination of hundreds of men have been taken and re tards of their physical condition and mortality recorded and collection of hundreds of dust samples nave been taken to correlate with these medical findings. Maximum Allowable Concentration We have established maximum allowable concentrations of dust based on experience in dusty industries. These figures are not absolute -- that is to say, we cannot sav that just above these figures you will get silicosis and just below them yot are m the safe range. They are a guide, however, and to the best of our knowledge no one has gotten silicosis with a dust concentration below these figures. The maxi mem allowable concentration for silicon dust is as follows: Silicon above 50% -- 5M.P.P.C.F. 5-50% -- 20 0-5% -- 50 Conclusion on Analysis In conclusion then the problem of measurement of dust m foundries requir the answers to these questions: 1. How much dust is there in the air? 2. What is the particle size distribution of the dust0 3. What is the chemical composition of the dust in the respirable size range (below 5 microns)? More progress has been made to prevent silicosis in the last 30 to 40 year than has been accomplished since the world began. In those foundries where the mis counts have been reduced to the maximum allowable concentration limit, we do no: know of a single case of silicosis which resulted from the exposure within this range This does not mean that our maximum allowable concentration will always remain as it now stands, since future scientific studies may change these figures slight1 y or a different basis for a maximum allowable concentration may be established. Thev ha\ proven to be a practical figure, since it is reasonably easy for a foundry to r> ' :y dust to these concentrations. Dust counts are for two purposes: . 1. Purely as an engineering measurement to determine the success of ventilation equipment or some other dust removal equipment. 2. For medical and engineering data to establish limits in order to provide proper occupational environment for all employee s. Industrial physicians, industrial hygienists, educational institutions, re search organizations and government agencies have, therefore, taken new strides toward improving your working environm'-nt so that you.may expect to live to enjoy old age . 18 - ** s Fig. 1--Greenburg-Smith impinger for sampling dust-laden atmosphere. r. ke 'k. Fig. 2--Liquid in impinger for wetting and suspending air-borne dust in liquid. t c 4 Fig. ii--Dust counting cell as viewed under microscope. Note large dust canticle, large souare is ^ nr.: each small square is IOC microns. Fig.5--Another dust field shoving a large dust par ticle . c Fig. 6--Electrostatic precipitator type of dust-laden air sampling device. t; 20 1 Fic* 10--X-ray spectrometer for analyring dust for free silica in the respirable range. 22 Fig. 12--Power pestle and mortar for further preparation of sample. Fig. 13--Sample of fine powder in metal lozenge. Close up view of x-ray source and the goniometer. 23 Fig. lit--Record chart from the x-ray spectrometer. QUARTZ STANDARD CURVE OCTOBER 1951 r Fig. 15--Curve used in conjunction with Fig. Ill to determine percentage of quartz in a sample. 2b HOUSEKEEPING by Herbert J. Weber* It is interesting to note that under the general topic of "Control of Dus;' housekeeping has been placed first in the course material of this Conference. This is appropriate since good housekeeping is a basic and primary element in any regi men of dust-control. Even the most soundly engineered and expensive ventilating systems cannot be effective without good housekeeping-a fact that can be reduced to proof. This is so because industrial housekeeping per se embraces in its defini tion not only the concept of well swept floors, clean windows, and orderliness but also the notions of decent wash and locker rooms, adequate illumination, and good maintenance of existing ventilating systems and other protective devices. It can probably be said that the greatest reduction in the incidence of occupational disease and of accidents in the foundry will be accomplished by good housekeeping. The elements of this discipline -- and it is just that -- are not a magnani mous benefaction of mangement. They are a good investment; they arc just good * business! They constitute almost a complete answer to the question: "What can i do about industrial hygiene?" Even the smallest and least capitalized plant can afford good housekeeping and yet it is so often ignored. If a plant manager were to walk into the treasurer's office and fin! :w e nty - dolla r bills lying on the floor, in the waste basket, or on the window ledge, he would be scandalized. Yet in his own plant, equipment and material -- all of which represent dollars -- are sometimes strewn about in the same careless manner. '.' hat damage the dust and dirt is not doing to his men, is being done to his motors, machine tools, and other equipment. Aside from the moral obligation to the em ployees, poor housekeeping is bad business because of the unnecessary hidden costs. There is a foundry in the middle west whose works manager decided 10 install a new concrete floor in the core room. When the contractor arrived to level off the sand and to drive stakes for the construction forms, he found a perfectly good concrete floor about a foot below the dirt! This story -- a true one -- needs no com ment. The unsavory reputation of the foundry industry of the past is not without . usti: 1 c a tion. In this regard I should like to quote from an address given by Wm. B. C.vcr., Chairman of the Board, American Brake Shoe Co. before the American .-our. irvmen's Regional Conference in Philadelphia in May 1949. *Chief Industrial Hygienist, American Brake Shoe Company, Medical Department, Chicago. 25 "Some of you sre -too young to remember .the founines of the early days - what terrible places they were for any man to work in. Unfortunately, there are still many foundries around the country which do not compare too favorable with those 01 the Dast. During vacations while in college, 40 years ago, 1 worked two summers in a small machine shop which had, as one of its lean-tos, an iron foundry in which 1 also worked at times. It was probably worse than the average but typical of many of the old time foundries. The pay rates were about the lowest and the working condi tions'the poorest in that vicinity. It was hard work. It was extremely hazardous work. For illumination molders had a smoky kerosene torch. A hand shake-out method made it possible for them to breathe in the maximum of dust. The metal was all carried with hand ladles from the cupola to the molds over a floor as uneven as a pasture. There were no wash rooms. In the winter, a piece of hot metal was tossed into a bucket of water when it came time to wash up. Heating a foundry in winter time was unheard of. It was not unusual to build fires on heaps of sand in the morn ing, especially after a few days' shutdown before starting to mold. The toilet facili ties were the great outdoors. Part of the young man's inherent resistance to a foundry job today comes out of past history -- that record of being an awful place to work. This generation still hears of the terrible burns suffered by molders of those days. The toughness necessary to be a foundry worker was real. " In the early days, the foundry industry depended largely on immigrant labor. Because of our compulsory educational system, the sons of those immigrants nave had at least high school education. The U. S. Government, by appropriations irom taxes, has made it possible for many ex-servicemen to receive a college edu cation. These people are not going to be attracted to an industry with a reputation for sub-standard working environment because they have the mental acumen and raining to find employment elsewhere. The industry can and must alone for the sins of the past by eliminating ex posure :o occupational disease and by adopting now the basic elements of a modern industrial environment, the principal one of which is good housekeeping. Without it, the better people will not be attracted to the industry and the good men may leave in search of other employment. If wc had th money, we can replace every machine or piece of equipment in tnc foundry, but wc can not so readily replace first class molders and we can not buy first class core makers -- we can only steal them from each other. It takes years to make a good foundryman and consequently the industry has a tremendous investment in people. To protect that investment and to make it possible and profit able to invest in newcomers, requires primarily a hygienic industrial environment which is attainable only by a regimen of good housekeeping. How many have had the experience of luring 20 men today; of paying for their pre - employment physical exa minations, ana of having 18 of them quit the next day and the remaining two the next m on ! h 0 Recently 1 read some interesting inspection reports of foundries made in iQ32. I should like to quote briefly from them. 26 1. "The salient features of this foundry arc its remarkably neat and orderly aspects -- and the total absence of any w a shtng fa c i 111 ics . '' 2. "The toilet and changing facilities in this foundry are adequate -- but there are no provisions for washing. " 3. "One woman works in the core room and has for many years. There is no woman's toilet. " These errors of omission, whether they are so intended or not, reflect 1P,e disregard of management for the welfare of its employees in the minds of the latter. This engenders a correlative attitude on their part towards management. Because of poor housekeeping, there are insurance carriers who either hesitate to insure a plant even at increased premium or refuse to insure it at all. a policy is carried by an insurance company that carrier is very interested in the hygienic and safe practices of the assured. Premium rates can often be substantially reduced by doing a better job of housekeeping because obviously the risk is less. Even if there have been no cases of occupational disease to date in a given plant, if the potential is there, the carrier cannot afford to tane a chance because a series of cases may reach full bloom at once. Furthermore the carrier cannot easily defend a plant in litigation where housekeeping is poor. Unions are beginning to insert health and safety clauses in their contracts". State factory inspectors are enforcing better working conditions. Failure to inaugur ate a comprehensive program of plant hygiene is to stand in the way of progress and is a sure way to lose money. 1 know a company that operates many foundries an.' it :s r.o: bv coincidence that the plant with the poorest housekeeping record also has the lowest production record and the highest cost per ton of castings. In our own Company, we operated 58 plants most of them foundries, with average population of 150 employees. \V e recently instituted a program whereby each piant is charged or credited in dollars for their safety and occupational di sease exnense. The system works as follows: 1. To start with, an audited premium is set up for each plant as required e\ the insurance company which is regulated by the State Insurance Law. The amount o: auniu-d nremium is arrived at by multiplying the manual rale (industry wide rale) u\ each S 1 00 . 00 of payroll. 2. Regardless of accident or occupational disease experience each plant pavs a basic minimum premium of 25 per cent of its audited premium. 3 The remaining 75 per cent of the total audited premium for all plants is men a 1! oca ted amongst them as follows a. The losses incurred by each plant during the preceding year are related by ratio to the total company losses. 27 b. Multiplying this ratio by the: total\of- 75 per cent of the audited premium for all plants results in the "Indicated Premium Based on Loss Experience. " 4. Adding this Experience Premium to the basic minimum premium yields the "Plant Total Premium." 5. Comparing this prerr im with that paid by the plant originally on audit gives the "Adjustment" due. To give an example: Assume a company of ter plants. Let S10, 000. 00 be the audited plant premium and $100, 000. 00 be the audited company premium. Let $5, 000. 00 be the losses on plant A and $100, 000. 00 be the total company losses. Then $5, 000. 00/$ 10, 000. 00 equals 1/20, the ratio of plant loss to the company loss. Seventy-five per cent of the company audited premium is $75, 000. 00 and 1/20 of $75, 000. 00 equals $3, 750. 00, the indicated premium based on losses. $3, 750. 00 plus the basic plant minimum premium (25% $10, 000. 00 or $2, 500. 00} equals $6, 250. 00 or the adjusted premium. The plant audited premium (S10, 000. 00) less the adjusted premium ($6,250.00) equals $3,750. 00 in credit due the plant. If the adjusted premium exceeded the audited premium the plant would be billed for the excess. We have plants that have earned as high as $12, 300. 00 in.a year which is credited to plant profit. This system can really bring about remarkable changes in plant housekeep ing because it deals in dollars just as production does. It can also be used where a company owns only one plant by charging or crediting the various departments with real dollars as a result of their occupational disease or accident record. Money is as surely lost by bad housekeeping as by poor production -volume and scrap products. A study of 43 foundries in New York State revealed the following startling relationships between housekeeping and the incidence of silicosis. Note in Table 1 that no foundries were classified as having good housekeep ing; only five were fair, eighteen poor, but most of them bad. Housekeeping Fair Poor Bad Plants 5 18 22 TABLE 1 Silicosis Incidence (Percent) Med. Max. 00 1.9 4. 4 5. 4 15. 4 13.8 Min. 1. 0 1. 0 0. 8 28 .- The mcii.in rare is lowest in plants having fair working conditions ani _.. ,or those showing bad housekeeping, the unnecessary accumulation of waste i-.alf. and other evidences of high dust exposure. The rang'' in silicosis rates .'so much iess for the "fair1- plants than for the others. Tins classification of foundries is based only upon an evaluation resulting a study of preliminary survey sheets and is not related to dust concentration Nevertheless, the trend indicated is significant and lends additional support ji r previous statements about housekeeping. In one of our own brass foundries we had approximately 14 cases of lead .to-jnc a month. With little change in the ventilating system but by an excellent ..pp^n of good housekeeping alone, we have not had a single case in over seven We routinely analyze for lead urine samples submitted by all men working - our brass foundries. In January, 1952 our series of urinalyses for the plant ~r,owcd every man to be in the normal range. If good housekeeping can accomplish ; a: in a brass foundry, it certainly qualifies as one of the most important factors in . .,c control of founlry dust. Figure 1 shows one section of that foundry. Parts of it ,, re vacuum cleaned every Saturday, so that in a month the entire plant -- super.ructures, windows, floors, cranes, duct work -- is thoroughly cleaned. There is a foundry in the midwest which had not been cleaned for 30 years, according io Us own figures. When the job was finally done, the amount of dust aKen from three buildings amounted to over 100 tons. Another foundry in the same area removed over 60 tons of overhead dust. Accumulations of overhead dust finally reach the angle of repose and dust : r cm the superstructures and floors is constantly made air-borne by building vibra tion. Particles of physiologically significant size (below 5 microns - a micron is . 23000th of an inch) will remain suspended in still air for verv long periods thus c on: a m inn :: ng the atmosphere long after the dust producing operation has ceased. Tables may be found which give rates of settling in still air for spherical particles of r.iife rent sizes. According to Stokes' law, a spherical particle having tiie same density as quartz and 100 microns in diameter will fall in still air at the ra'e o: 160 fpm, a 30 micron panicle at 40 fpm; a 10 micron particle at 1.8 fpm, and a particle ! micron m diam-tcr at 0.016 fpm or 1 ft per hr in still air. The dusts of a particle size which is dangerous arc just the ones that linger in the breathing zone. This law emphasizes the important fact that blowing down a foundry as it is cal'en, :ry sweeping, and poor housekeeping are conducive to occupational disease because fine dust once made air-borne does not setLle rapidly. 1 have found high dust concentrations in foundries with very good ventilating systems because the floors and structural members were seldom if ever cleaned. For this reason, I have beer strongly in favor of built-in vacuum cleaning systems capable of maintaining a suc tion of 11 in. of mercury which is approximately equivalent to a negative pressure of 5 12 psi. 29 Mobile units usually have a vacuum of only 5 in to 6 in. of mercury which in most cas 'S is not enough for heavy duly foundry work. The vacuum system can be made to pay for itself. It can be used to clean out molds in preference to using expensive compressed air and blowing the dust all over the plant. Bins, shake-out pits, annealing pits, core racks, pattern storage bins, etc. , win. h a r tough on the janitor or maintenance crew, can be cleaned with the system. Silica flour, bentonite, and binders can be conveyed into the sand system a: the rate of 100 lb per min by vacuum. In non-ferrous work, metal chips and filings can be gathered from machine shop floors and conveyed to storage bins for remelt by means of the machine. Most foundries use manual methods to a large extent and satisfactory dust control need not always involve elaborate local exhaust systems. Rather it is largely a matter of housekeeping. To keep a plant clean and orderly requires only the will to do so and the application of common sense. Many foundries allow discarded material to accumulate tiiereby taking up valuable floor space and making the cleaning job more difficult. In many cases disposal or proper storage of seldom used patterns or flasks will more than pay for itself in increased usable floor space and in greater ease of regular clean up. Figure 2 shows a very good example of poor housekeeping. The picture was taken in a brass foundry where the dirt necessarily contains a high percentage of lead dust. It is quite evident that no one can work efficiently in such a cluttered area and any vibration or disturbance of the settled lead dust is certain to set it air-borne." Figure 3 shows a very good example of a ladle heater exhaust hood, the benefits of which are seriously reduced by the type of housekeeping that prevails. Figure 4 shows the rear view of sound proofed and exhausted chipping ben. hcs. The design and efficiency are excellent yet note the dirty condition behind the benches. Figure 5 furnishes a very fine example of an exhaust hood over a cupola spout. It is evident how very little clean-up has been done in the area. The picture snows clearly the dust on the building columns, ladder and other equipment. Notice the milk bottle next to the fireclay plugs. Lead dust falls in that bottle and provides a simple way of becoming intoxicated on milk. It is not the pleasant form of intoxica tion but the kind known as lead intoxication or plumbism. Figures b, 7, 8 and 9 provide examples of fair housekeeping and Figures 10, I !, 12 ar.d 13 arc models of good foundry housekeeping. The pictures impress me with one primary fact, namely; that it is foolish to spend a lot of money for expensive exhaust equipment and to ignore the clean-up phase of industrial hygiene. It is, as it were, putting the cart before the horse. A good exhaust hood may cost several thousand dollars to reduce half of the atmospheric contaminants. The other half can be removed by good housekeeping for a few dollars. Which pays the greater dividends' This is not to disparage exhaust ventilation; it is to put housekeeping in its prop-r orier of importance. 3C \ 3. \ er lie ::a . a' yt c ' ':: r We said before that prooer illumination is also a part of any program o: an- industrial hygiene. Figure 14 shows the midrib' bay of a manganese smel ... -ry w ii 're the av rag' miensiiy w as 1.6 loot - eandles. Can one expect proriii.-- high morale, or employee health in such an environment? Figure 1 5 siious the same bay after the intensity was increased to i ! ... . -anrilcs. Even this level is inadequate but it shows a vast improvement over : :C value of 1.3 foot can 11 'S. Fioure 16 shows the cast bav' of the same found rv. The illumination level a 2 s too low to register on a light meter. Figure 17 s tows the same bay after the intensity was increased to 10.3 :c r.: - candies. There isashigh as a 20 per cent loss of efficiency of a luminaire if the reflectors are noi kept clean. Her? again the importance of good housekeeping is evident ! Good maintenance is also a part of good hous keeping. In Figur- 18 is s.-iown an example of poor maintenance. The cold air ducts protruding through the all were originally designed to introduce fresh air about 1 ft from the floor. Tiie vertical sections of the ducts were so badly damaged by the chill molds pictured, tna: par: of the duct was removed. Note also the broken windows and open windows that cause air tc short circuit to th" overhead ventilators, thus defeating the design er's pvrnose. The money for the fresh air ducts in this case is wasted because of can maintenance which is synonomous for bad housekeeping. Figure 1Q shows a broken furnace hood s>.hich is not as efficient as origina 1 ncs. j".ed Fa- m a i n i c r a n c e means that wc are not getting the return on our invest - Here arc a few tilings to check which 1 have personally encountered and e n ; a n nconlc were surprised '.hat the dust and fume c on ce nt r a u ons were so high. : F-rok n or disconnected exhaust hoods. 2 hroKcr., stuffed, or disconnected exhaust ducts. We once found a ".'oilman's overall jammed in the mam header of an exhaust system . 3 Blast gates removed or jammed shut. 4. Burned out power ventilators. a. Reversed fans. A motor burned out on a certain dust collector. The maintenance man installed another and had the motor running backwards. I 31 6. Broken or open windows in the monitor which caused short circuitin': of the air to tiie power ventilator. 7. Loose fan belts causing slippage and loss of suction. 6. V rong wiring. One foundry bought an industrial vacuum cleaner which was wired for 440 volt current and was operating it on a 220 volt line. This gave them half the rpm and half the suction and they had become convinced that vacuum cleaners are no good. 9. Dirty dust collector bags so clogged that the suction on the exhaust system was reduced almost to none. 10. Torn dust collector bags, so that there was no dust collec tion at all and most of the contaminant was re-entering the foundry. 1 1. Man cooler fans directed in such a way as to neutralize the effects of an exhaust hood or so as to disperse a contaminant all over the foundry. 12. Broken or burned out lamps and dirty reflectors in the light ing system which reduced the intended intensity. 13. Broken doors on sand blast cabinets. 1-1. Fresh air intakes covered with debris so that no fresh air could enter the plant. 15. The indiscriminate use of compressed air for cleaning. 16. eather caps on certain types of power ventilators jammed shut so that the fan could discharge no air. Cnee a ventilating system is in perfect operating condition a maintenance man can very easily ciieck its performance rapidly be a simple U tube water gage. 3y taking static pressure readings on each side of the dust collector, on the main duct, and on each branch, basic normal pressures can be determined. Any serious increase or decrease m these readings indicate trouble in the system. I have purposely refrained from giving here a check list for plant house keeping because 1 believe each plant has its own specific problems and some people are better housekeepers than others. But if a start is made, cleanliness engenders further cleanliness and progress will follow. It is usually a good idea to make each man responsible for the condition of his work station and to grant awards to those who do the best job. If a shop is al ready littered with debris and covered with dirt and dust what difference does a little more make'5 V. e all hesitate however to soil a clean place. Diace. " The old adage is still true: "A place for everything, and everything in its 32 Figure 1 I Figure 2 Figure 3 *l ! f * 17 igure 8 Figure 9 FiSure 10 Figure 11 33 Figure 12 .1 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 31* CONTROL OF DUST ISOLATION, SUBSTITUTION, AND WETTING AGENTS by E. G. Mciter* The dust problem in the foundry is recognized by the larger foundries, but ,,,av no: be by the smaller ones. This lack of dust control in the smaller plants is not necessarily due to lack of interest but rather to the fact that they have not been -eached by industrial hygiene and safety engineers to explain the importance and be nefits to be derived from an adequate dust control program. Naturally, to develop an effective dust control program it must be sold to too management, then to the supervisory force, and finally to the workers them selves. This selling job cannot be done by mail distribution of bulletins, advertising circulars or the like, but must be accomplished by personal calls by competent in dustrial hygiene or safety engineers. To explain the benefits of a foundry dust control program, we must rememoer that management in general is fearful of "what's new" until it has proven itself. e can, therefore, expect at the beginning to receive some opposition to any changes in plant operations which may be suggested. Laying the proper groundwork or educating management to appreciate the benefits of a dust control program is therefore important before we can expect to receive much cooperation. It is not enough to tell an employer that tiie air in his foundry has so many million dust particles per cubic foot of air of a specified free silica content, because of which he should initiate a dust control program. What he wants to know is the practical significance of these figures. Are additional ventilating facilities neces sary' V. ill tiie proposed changes slow down production or lead to an inferior cast ing0 h,-at are his legal responsibilities with reference to occupational disease0 'tactical answers to these questions will invariably sell the foundry dust control program, to management. Having sold management on the acceptance of the program, the importance o: dust control may be brought to the attention of its employees in two ways. The medical aspects of the dust problem and the general precautionary measures to be .aken may well be discussed with the employee by the examining physician during p r e - employm en t and routine physical examinations. Additional information may be given by the industrial nurse during the employee's visit to the first aid room. The engineering aspects of the problem including the reasons for protective measures should be given through the same channels as the job instructions. ^Director, Industrial Hygiene Division, Employers Mutual Liability -nsurance Co. of Wisconsin, Milwaukee. 35 The writer feels that too little-attention is paid to job training with respect to the necessity of dust control measures. Herein lies the failure of many a well designed program. Job training in this phase of the work can very well be extended. Supervision and enforcement are important. Factors such as plant layout, type and size of castings produced, and exist ing ventilation facilities will vary greatly from plant to plant, and it will be necessary to discuss dust control measures by isolation, substitution and wetting agents in general rather than in specific terms. Nevertheless certain principles that will be mentioned are applicable to all foundries. 1. Isolating Dusty Operations Dust control by "isolation" is based on the theory to expose only those employees actually required to conduct the dust producing operations. In this way only a minimum number of employees are exposed which in most foundries is only a small percentage of the total employment. Isolation may be in space or in time, and a brief discussion of each method is: (a) Isolation in space. Dust producing operations wherever possible should be segregated in separate buildings or departments, or completely enclosed within a department. The grouping of such dust producing operations also aids materially in the effective appli cation of local exhaust or other dust control measures. In some instances, it may be more feasible to isolate the non-dusty rather than the dusty operations. For example, core making is not dusty in itself and the dust concentration in the core room is generally low provided good housekeeping is maintained. Usually the dust to which core makers are exposed comes from nearby operations net associated with their jobs. It is, therefore, highly desirable to isolate the core room from other dust pro ducing operations. (b) Isolation in time. Dust producing operations may be delayed to the night shift or at other times when only a minimum number of workers are exposed. This type of isolation has gained wide favor in foundries by limiting the shake-out to the night shift when only a small crew, preferably protected by respirators, is in the foundry. Sand conditioning is another operation which should be done on the night shift and the operators protected by respirators. Emptying dust collectors, and major cleanup operations may also be isolated in this manner. Dust control by isolation as to space or time is especially applicable to small foundries because generally speaking it is the simplest method to apply and it is the least costly to install and operate. 36 2. Substitution of Less Toxic Materials. As all dusts are not equally hazardous. t:ie principle of substituting a nonox-c or less toxi material for a toxic one is a well recognized procedure for the ,,. jncering control of occupational disease. This metnod should always receive due 'onsideration because it attacks the problem at the source and in addition it is both effective and usually inexpensive. An important constituent of foundry dust, from the health standpoint, is the ;ree silica which is present in molding sands, core sands, parting compounds, and sandblast sand. The elimination of free silica containing materials, or the use of materials containing less free silica is therefore desirable. An example of a successful substitution is the steel grit or shot for sand :n abrasive blasting. Studies made in the past by the U.S. Public Health Service and ov other official and non-official agencies have shown this substitution for sand re duces both the dust concentration and the percentage of free silica in the dust to which the blast operator is exposed. It should be borne in mind that the use of nonsilicious abrasive alone does not entirely solve the dust problem as dust control measures are still necessary. In abrasive blasting operations where sand must be used, commercial ea upment is available which if properly installed and operated, provides adequate nrotection for the operator. A further example of substitution is the use of parting compounds containmc little or no free silica. Ground silica was formerly widely used, but in past years has giver, way to other compounds which are less or non-injurious to health. As an additional control measure, the so-called nonsilica parting compounds should also oe applied without the unnecessary scattering of dust. 3. V. ettmg Agents. The application of water is probably the oldest method of dust control. In the loundry it has been used principally for sprinkling floors, gangways and aisles to prevent the dispersion of dust. It is well known, however, that water does not wet small dust particles very readily; nor does it rapidly penetrate a porous mold. It. other words, ordinary water is often "not wet enough" for many industrial applica tions. To overcome tms undesirable characteristic of water, chemists within the past 2 0 years have developed materials which, when added to water even in minute quantities, will cause a considerable reduction in its surface tension. Such materials are known as wetting agents. Wetting agents, designed for specific uses, are now commercially avail able which reduce the surface tension of water and increase the wettability of such materials as are used in foundry operations. Wet water spreads rapidly and pene trates much like a penetrating oil whica creeps into all surfaces and crevices. Dusts difticult to wet can be wetted if the proper compound is used and correctly applied. 37 I f I I l i These wetting agents are shijped in concentrated form either as a liquid or as a solid (cartridge type) and usually require dilution before use. To accomplish this, automatic proportioning equipment is now available, and it is a necessary re quirement for the successful use of wetting agents. The recommended dilution is 1 part of concentrate to 1000 parts of water by volume. The solid cartridge, which is generally equivalent to 1 gallon of liquid concentrate will treat approximately 1000 gallons of water. Wet water is usually applied by spraying through one or more nozzles at pressures' varying from 75 to 125 psi. For best results it is important to select a good type nozzle and spray pressure to create the correct size and pattern of spray droplets. Regardless of how efficient the wetting agent may be, if the nozzle and spray are not at a proper location, poor results will be obtained. The discussion of wet water as it concerns tne foundry industry will be limited to the application of dust control. Other suggested uses, such as, tempering molding sand and core sand, as well as a core wash are beyond the scope of this pa per. The applications given are suggestive and are not intended to cover all phases of dust control. foundry: Wet water may be employed in three different ways to control dust in the 1. As a means of preventing the dispersion of dust which may have accumulated on floors. 2. To suppress dust at the point of origin. 3. To remove dust from the air after it has escaped from its source. A brief discussion of each method is: 1. As a means of preventing the dispersion of dust which may have accu mulated on floors, many foundries now sprinkle floors, gangways, and aisles with water to lay the dust, and there is a definite need for an improved control method. Crdmary water wets only the surface of the floor sand, thereby causing mud, or if loo much is applied causes puddles which introduces the hazard caused by the spat tering of metal. As little penetration takes place, air currents absorb the moisture rapidly, allowing the floor to become dusty again soon after sprinkling. Wet water, however, will penetrate and disperse through the sand, clay or other materials with out forming mud or pools of water. Walking over the newly sprayed floors will not disturb the top surface and expose the dry dust underneath, but will merely pack the surface. Again it must be emphasized that correct application of the wet water is necessary to secure optimum results. 2. In suppressing dust at its point of origin, wet water has been found use ful to control du.-t arising from sand conditioning machines at the locations where sand is dumped into hoppers by bucket or conveyor. Flat spray nozzles mounted above the hoppers provide a mist blanket which settles the dust. 38 `. c ' i.itic i' *' O ' T 7 k : v. c :h> ;nc - .ch s;:c: < i 115 l : iv.oun and e :K-cor. applic less. contri t ion a  A further application is to prevent the dry binders added to sand mullcrs -om Deinc exhausted to the dust collector. The method recommended is to install at soray nozzles on the periphery of the muller casing and spray toward the center, .--rr.mg a liquid blanket over the muller. 3. To remove dust from the air after it has escaped from its source, wet ater has been used to control dust at shake-out operations which are either ventilat- or unventilated. Where ventilation is applied, it is used to supplement the ventiia'.on already provided. Methods of spraying vary. Where no ventilation is applied, 0-e method employs a cluster of solid cone atomizing nozzles mounted on vertical 2-c horizontal piping extending over the top of the shake-out. If this construction nterfere->with crane operation, a swivel pipe fitting can be installed which allows the nozzle piping to swing back against the wall or post. Some foundries use cranes to -emove large heavy castings from the flask. The flask is swung by the crane and oounced against another casting usually located in the center of the shake-out floor. o_ich operations are very dusty, and the dust is hard to control, due to the various sizes of castings and the large areas covered. Wet water can be used to control the dust at such operations by installing the spray nozzles on the crane bridge and mounting the water tank on the crane itself. Unfortunately there is a lack of published data relative to the application and efficiency of wetting agents for foundry dust control. Such data no doubt will uecome available from time to time. While the method may have only a limited application in some foundries, and should not be regarded as a cure-all, neverthe less. it should be tried and experimented with as an additional tool for foundry dust control. , Conclusion The dust hazard in the foundry industry can be controlled by proper educa tion and supervision of all concerned. 39 TRAINING COURSE OUTLINE ON FUNDAMENTALS OF FOUNDRY SAFET Basics of Foundry Safety (Organizing a Safety Program) Foremen's Safety Conferences - Committees The Foreman - The Key Man Building Safety into the Plant Plant Inspections Building Safety into the Working Force (Employee Training) Creating and Maintaining Interest in Safety Safeguarding Mechanical Equipment Electrical Hazards Handling Materials Personal Protective Equipment Accident Records and Analysis Fire Prevention and Protection Industrial Health PERSONAL PROTECTIVE EQUIPMENT A. Respiratory Equipment 1. Air supplied suits a. Used under conditions which are both immediately hazardous to life and corrosive to the skin and mucous membranes b. Air connections to both hood and body of suit - (1) Substantial harness for dragging hose lines c. No authoritative specifications available 2. Self-contained breathing apparatus a. Used under conditions dangerous to life and in accessible by means of hose lines b. To be used only by crews trained in operation c. Types available are (1) Oxygen tank (2) Chemical types which produce their own oxygen (3) Air tank types d. Oxygen tank types are approved by U. S. Bureau of Mines under American Standards Assn. Code Z2-1938 3. Hose masks a. Used under conditions immediately hazardous to life but accessible by means of a hose line b. Tight-fitting face mask and hose line through which it is possible to breathe if the air supply fails (1) Substantial harness must be worn for dragging the hose line and life line c. Air supplied by low pressure blower; may be poweroperated, but must be equipped to operate by hand d. Approval by U. S. Bureau of Mines as above 4. Air-line respirators a. Used where man can escape without respiratory protection b. Air supply preferably from high-pressure blower not in ternally lubricated, but may be from compressor c. Abrasive blasting protectors are one special type d. Approval by U. S. Bureau of Mines - 26 - -i I A. Respiratory Equipment (Continued) 5. Gas masks For conditions which may be toxic and irritating; not useful in protecting against oxygen deficiency a. Tight face-piece with separate canister of chemicals carried on harness b. Canister types are: (1) Organic vapors - black (2) Acid gases - white (3) Organic vapor and acid gas mixtures - yellow (4) Ammonia - green (5) Organic vapors, acid gases, and ammonia - brown (6) All industrial gases including carbon monoxide, smoke and fumes - red Hydrocyanic acid - white with ereen stripes Chlorine - white with yellow stripes c. Definite routine of inspection and care reauired for successful use d. Employees should be carefully trained in use under emergency conditions e. Approval by U. S. Bureau of Mines as above 6. Cartridge respirators a. Used where injury will occur only by long exposure b. Have face-piece and canister combined c. Only types approved at present are for (1) Organic vapors (2) Dust, fumes and mists in combination with Organic vapors 7. Filter respirators a. Used only for protection against dust, mist, fog, and other particulate matter b. Requirements for satisfactory filter include: (1) Sufficiently fine to filter out all of the particulate matter from the air (2) Resistance low enough not to interfere with the man's work (3) Specifications are compromise between the two c. Approvals are issued on basis of schedule of several test procedures for protection against 1) Pneumoconiosis producing dust !2) Toxic dusts 3) Fumes and mists - 27 - 8. Care of respiratory protective equipment a. Cleaning after each use b. Periodic sterilization c. Storage in clean, dry place d. Marking for the use of particular individual B. Head Protection 1. Hard hats (a) Impact resistance in both hat and cradle 2. High dielectric strength often reomred 3- U. S. Treasury Department Specification #367-A is usually quoted. There is no approving agency 4. Hair protection 5. Acid hoods C. Eye protection 1. Chemical Goggles a. Splash-proof b. Vapor-proof 2. Impact Goggles a. Eye-cup b. Spectacle type with or without side shields 3. Miscellaneous types (half and half, glass blowers, etc.) 4. Face shields for protection from mild impact 5. Babbitting masks for ptotection from molten metal 6. Welding masks and goggles for protection from ultra-violet, infra-red, and visible radiation D. Foot Protection 1. Safety toe shoes and boots a. American Standards Assn. Z-41 series codes b. External foot guards 2. Conductive shoes 3. Non-sparking shoes for explosive surroundings 4. Wooden-soled shoes for protection from heat and wet E. Hand protection: gloves, pads, metal mesh F. Body protection 1. From heat and hot metal a. Leather, asbestos, wool and other flame-proofed fabrics b. American Standards Assn. L-18 series codes on leather and asbestos garments - 28 - A'-- ' ' - -; Z'- f ?' 's * ) * ~v'-^ C'* :': yi -:-`i-:.';; \-i<~ ' ' ' 1 . -"-"'V- -' f 7i i tW . M F. Body protection (Continued) 2. From cuts and impacts - leather, padded canvas, metal clothing 3. From water and solutions - impervious clothing G. Safety belts 1. Construction: leather, fabric 2. Tail lines 3. Care and maintenance References: Safe Practices Pamphlets - No. 16 - "Protective Clothing" No. 64 - "Respiratory Pro tective Equipment" - 29 - \' References: "Symposium on Foundry Dust Control" American Foundrymen's Society "Fundamentals of Design, Control, Operation and Maintenance of Exhaust Systems" American Foundrymen's Society "Industrial Health Engineering" by Allen D. Brandt John Wiley k Sons, New York, 1947 - $6.00 "Industrial Hygiene and Toxicology" edited by Frank A. Patty, Interscience Publishers, New York, 1949 - $25. 00 - 38 - SYMPOSIUM ON FOUNDRY SAFETY HEALTH AND AIR POLLUTION Papers presented at a Conference on Safety, Health and Air Pollution at the University of Illinois, Division of University Extension, February 17, 18 and 19, 1953, at Urbana,Hl. Conducted by the American Foundrymen's Society and the Department of Mechanical Engineering, University of Illinois. AMERICAN FOUNDRYMEN'S SOCIETY TABLE OF CONTENTS Safety a Part of Production - by I. R Wagner .... This address presented by Mr. Wagner, President of American Foundrymen's Society at Conference Dinner, Wed. evening, Feb. 18, 1953. SAFETY Safety Practices- in the Production of Ductile Iron by Dr R. E. Savage .................................. ............................................................... Safety Training in the Foundry by W. N. Davis ........................................... Materials Handling in the Foundry - by G. W. Harper .......................... Safe Handling of Magnesium in Foundry Operationsby F. P. Stricter and H. A. Schertel ............................................................. Labeling Codes and the Foundry Industry by S. C. Rothmann ................................................................................................... HEALTH Foundry Facts about Sihc osis and Siderosis by Dr. L. E. Hamlin................................................................................................... The Effect of Resin and Fluorine Fumes in Shell M olding - by H. J. Weber ..................................................................... dermatitis Prevention in the Foundry Industry by Dr. F. L. Van Atta............................................................................................... An Introduction to the Noise Problem by J. O. Kraehenbuehl............................................................................................... AIR POLLUTION Methods of Dust Sampling - by Dr. L. D. Wilson....................................... Lust Sampling Apparatus - Instruments used by Federal, State and Municipal Authorities to Measure Air Pollution - by N. W. Hartz ................................................ Practical Control Methods of Foundry Air Pollution - by R. H. Moore ....................................................................................................... Pw to Maintain Foundry Ventilation and Dust Collection Systems - by K. M. Smith............................................................. Page 1 5 14 20 23 30. 43 54 60 65 76 89 99 107  - <"v- >_....... * J: ,.7 -,. -_:r.-....,r, ;~7~y ;'# ?.r.-'^-.**" . -v-^;.'tv v',., ,_.. .#3?. ENGINEERING MANUAL FOR CONTROL OF IN-PLANT ENVIRONMENT IN FOUNDRIES f AMERICAN FOUNDRYMEN'S SOCIETY Des Plaines. Illinois FOUNDRY ENVIRONMENT CONTROL ! per cubic meter of air. This limit mav easily be ex ceeded during the phosphorizing phase of melting phosphor-copper. Local exhaust ventilation usually is indicated. Resina With the advent of shell molding, more resins now are being used in foundry operations. Such resins are of the thermo-setting type: once the resin is cured, washes and spravs. This material falls in the dan gerous particle size range, and is usually 100 per cent free silica. Zircon, which is nomoxn and ha>, a specific gravity of approximately twice that of silica, has been an effective substitute for silica flour in some applications. Because of its density and tendency to flocculate, zircon dust settles very rapidly. Sand-handling and conditioning systems, shakeout. , i t ` it cannot be softened or remolded. Types now being and sometimes sand-slinging operations constitute j marketed include the phenol-formaldehyde and urea- sources of exposures to silica dust. j formaldehyde resins, some of which contain hexa- Dust sources usually are more severe in mechanized tnethvleneietramine (known as "Hex" in the trade). plants, but this is offset by the fact that such plants The phenol-formaldehyde resins give off odors of are subject to better control bv means of local exhaust phenol and formaldehyde on heating. Urea decom systems. poses to ammonia and carbon dioxide so that in shell molding a distinct odor of ammonia may be noted. Good housekeeping is one of the most important Hexamethylenetetramine is a skin irritant, and de means of controlling the hazard from silica dust. Good composes and releases formaldehyde upon exposure evidence exists that the incidence of silicosis is in to heat. versely proportional to good housekeeping. The higher All of these resins are toxic, but protection lies in the level of housekeeping, the losver the number of the^fact that in severe concentrations tuan cannot cases of occupational disease. tolerate them. Thus, in practice, fumes from the resins will at most be a nuisance and the degree of nuisance will indicate whether exhaust ventilation is justifiable. Silicones In foundries, silicones are used as mold-release Some resins in use are skin irritants and are cap agents during shell molding. Experience to date indi able of producing dermatitis in susceptible persons. cates that they are not a serious hazard to health. Resin dust suspended in air. like cereal flour or coal dust, can be highly explosive. Nonhydrolyzable silicones used as mold-release agents are of a very low order of toxicitv. From a Sea Coal Sea coal is principally carbon and is a common in practical standpoint, die hazards from handling them are minor. However, silicones are neyv chemicals and gredient of molding sand used for facing in the foundry. Carbon dust gives rise to a condition of the toxicological studies made are insufficient to deter mine that the nonhvdrolyzing types can be ignored. lungs called anthracosis. which is responsible for char acteristic shadows in a chest x-ray. Anthracosis has been considered thus far to be a relatively harmless < ondition. Silica Silica is one of the principal atmospheric contam inants in the foundry. The chemically combined sili cas. other than asliestos. are regarded as being physio logically inert. Thus silicates such as bentonites, slag uool. etc., are not known to produce disabling di sease. Free silica (SiOL.) causes the occupational disease known as silicosis, which is characterized in x-ravs principalis bv nodular shadows due to true fibrosis or scarring of the lung tissue, and clinically bv decrease Although the nonhvdrolvzing types of silicones ap pear neither toxic nor irritating, the hvdrolvzing types are highly corrosive. Tliev present practical hazards from vapor inhalation and contact with the skin and eves. In dangerous concentrations thev have adequate warning properties in that an employee could not tolerate an atmosphere (hat would be harmful to him. Care should be used in handling the hvdrolvzing types, since a small droplet splashed in the eye could cause serious damage and even loss of the eve. Direct skin contact, while likelv to cause a severe bum. is not apt to cause death unless a large portion of the bodv is exposed. Since many types of silimnes are available, safe * of pulmonary function. It is disabling in advanced practices indicate that only those of a low order of ' stages or when accompanied bv tuberculous infection. Usually three factors must be present simultaneously in order to produce silicosis: toxicity should be used as mold-release agents. These are the methyl, mixed methyl, and phenvl-polysiloxane types. { * 1) Duration of exposure. Two sears or longer arc required, depending on degree of exposure. Solvents (General) 2) Respirable particle size. Particles of free silica in excess of 5 microns in diameter are not regarded as being physiologically significant because thes are too large to reach the innermost part of the lungs where reaction occurs. Because of the large number of solvents used in' the foundry, it is impractical to treat them specifically here. However, no absolutely safe solvent exists--ex cept. perhaps, water. Some solvents are more toxic than others, but all of them can be used safely if the 3) Concentration of dust. The tolerable concentration toxic properties are known and safe handling pro depends on the percentage of free silica in dust cedures are followed. (Table I of appendix to this section). A major source of exposure is the uncontrolled use of silica flour either in molding sand or in core All containers of solvents should have warning la bels attached, giving the chemical name and stating the handling precautions to be followed. For example. VESTILATlON ^S^ HYGlENt- l^O^KM^^^^ , - CARBON TETRACHLORIDE DANCER! HAZARDOUS VAPOR AND LIQUID MAY BE FATAL IF INHALED OR SWALLOWED USE only with adequate ventilation DO NOT uaa in confined unventilated placet without protective reipiratory equipment DO NOT breathe vapor AVOID prolonfed or repeated contact with tkin DO NOT take internally Some states alreadv have labeling codes that have the force and effect of law. Sinte most solvents are flammable, they present the dancer of fire or explosion in addition to their toxic properties. Given the chemical (not trade) name of the in gredients. the characteristics and dangers of the sol vent can be ascertained. Threshold limits are of wide ranee because of varied toxicity factors, and maximum allowable concentrations range from 1 part per mil lion for nitrobenzene, to 500 parts per million for petroleum naphtha. Sulphur Dioxide Sulphur used as a deoxidant in the manufacture of magnesium castings bums down to sulphur dioxide. Breathing zone concentrations of the dioxide gas vary during the production of magnesium castings. A concentration of 10 parts pier million is common, and 50 parts pier million is rare. Maximum allowable concentration is 10 parts per million. Continued exposures in excess of the maximum alowable concentration produce inflammation of the respirators svstem, increased fatigue, excess acid in the urine, and alteration of the senses of smell and taste. Exposure to concentrations of the order of 500 parts per million are dangerous to life. In foundries this value will not be reached. Concentrations in ex cess of the maximum allowable are so intolerable to man that he will not remain in an atmosphere dan gerous to his life. The gas mav be regarded as an irritant nuisance and depending on degree present, exhaust ventila tion mas be required. Tellurium Tellurium is used in foundn practice to increase the chill-depth hardness and to improve the machinability of alloys. It is generally used in yen small amounts (5 grams to 800 lb of metal). Fumes of the element are toxic, characterized prin cipally by a garlic odor of the breath and urine, sup pression of sweat, drvness of the mouth, metallic taste, loss of appetite, salivation, and vomiting. Serious in dustrial poisonings are rare. Maximum allowable concentration is 0.1 milligrams pier cubic meter of air. If foul breath is to be avoided, this value should not be exceeded. Systemic poisoning does not occur unless the exposure is to a concentra tion of 0.8 milligrams or more per cubic meter of air. For practical purposes, the presence or absence of "tellurium breath" can be relied upon to measure the degree of exposure. If this is heeded as an indica tion of the need for control measures, injurious ex posure is not likely to occur. Tin The metal tin is commonly used in alloys and is considered nontoxic. Inhalation of tin oxide over long periods may result in a nondisabling pneumoconiosis, as demonstrated by x-rays. No cases have been re ported in the foundry industry. In practice, use of tin does not present a health problem. No maximum allowable concentration has been established. Welding (See Welding and Wood Working Section 9.) Zinc Inhalation of the fumes of zinc oxide gives rise to a malaria-like illness called brass-founders ague, zinc chills, smelter shakes, or metal fume fever. The illness rarely lasts more than a day, causes no permanent disability, and is never fatal. When brass contains zinc, fumes of the oxideare readily given of! in voluminous amount during melTing and pouring because of the low boiling point of the metal. Maximum allowable concentration is 15 milligrams per cubic meter of air. APPENDIX MAXIMUM PERMISSIBLE LIMITS OF AIR CONTAMINATION The following maximum allowable concentration tM.A.C.) values for continuous 8hr ex posure are recommended by the American Conference of Governmental Industrial Hvgienists. and are revised when toxicological data warrants. GASES AND VAPORS Substance M.A.C. (ppm*) AcnnUlehtdr . 200 Acetic acids 10 Acetic anhydride . . . cetonr crolein MX) 0/. Aavlomtrile ................................... . 20 Ammonia ............ 100 ppm --pan per million. Amvl acetate ..................... .............. 200 uo-Amvl alcohol ............ .............. 100 Aniline ......................... Arsine .................... .............. 0.03 Benzene ilientoli .......... ................ S3 Bromine ................ .............. I 1. 3-Buudiene............. n-Buianol ................... ...............1.000 .............. 50 2. Butanone ....................... ............... 2.30 n. Butvl acetate................. .............. 200 Bunl "celloiolse " ............. .............. 200 Carbon dioxide ................. Carton disulfide ...................... ........ 20 Carbon monoxide.................... ........ 100 Carbon tetrachloride .............. ........ 50 "Cellosolve" .............................. ........ 200 "Cellosolve" acetate................ .... 100 Chlorine ............................................. 1 2-C.hlorobutadiene................ 25 Chloroform ................................. .... 100 l-Chioro-l-niiroprnpane .... ... 20 C.vdohexane .............................. . 400 Ciclohexanol .................... 100 Cirlohexanone ... .100 V'rX' vi;-- -~'V. -I-V. ~T; - -T SECTION 4 Molding and Coremaking Problems The operations of coremaking and shell molding involve sand preparation, and are basicallv the same in nil branches of the foimdn industry whether the operations be mechanized or not. However health hazards, if anv, arising out of such processes varv not onlv from shop to shop but from workman to work man. Some casting processes require more critical sand preparation than others: parting and facing com pounds van in degree of toxicity; some shops use core blower mat bines, others do not; the manual applica tion ol silica flom 10 a mold face may l>e done in a wile manner b\ one molder. whereas the same job mas be hazardous when performed br a careless one. It is bevond the scope of this section to consider all the differences in shop practices and conditions that might be encountered in sand preparation, core making and molding, hence recommended safe protedures herein described refer to general foundry practice. It should be borne in mind that regulators codes b\ an\ authority of jurisdiction must be com plied with regardless of the recommendations in this Manual. SAND PREPARATION For consenience. several operations mas be classi fied under the general heading of sand preparation as follows- 1; l nicMdins 2 Comcunz Sionn" receivin';1 A\ Devins and cnolm" 5i Mi\m" It should also be kept in mind that sand used in foundrs practice usually is a mixture of sand grains, silica flour, bentonite, carbon, various binders and metallic impurities Thus the tendency to regard silica as the sole potential health hazard in sand preparation should be avoided. Sand constants reused eventually becomes contaminated with metallic particles, and in the case, for example, of the manu facture of high-lead bronze or bervllium-copper cast ings. the contamination from lead or bervilium mas be a far greater health hazard than that due to pure 'ilica dust. Thus the existence of a health hazard resulting from ans of the five operations previously mentioned depends on a number of factors as follows: l> Phssical state of the sand -< Chemical composition of the sand >i Method of operation or handling !' Frequencs and duration of dusts exposure In lieu of a quantitative hygienic studs, application f these four factors to a specific situation should en able the foundrvman to approximate!' evaluate an exposure. If a health hazard is then found to exist control measures mav be applied according to the ventilating principles and methods set forth in Sec tions 2 and 3 of this Manual. Bearing in mind these four basic factors, it mav tie of benefit to consider their application to a specific operation and wherein health may be affected bs them. For example, applying these factors to the operation of sand unloading, the following analysis mav be made: Factors Physical State of Sand li New sand alrcads screened and dint free 2) New sand wet condition 3) Nev <and fine and dr\ 1) t sell sand Effect on Health No health hazard No health hazard Potential hazard Potential hazaul Chemical Composition of Sand M Olivine imixture of \o health hnrnrd silicate* and oxideM anil zirromte sands 2) Class (mixture of No health hazard silicuesi and inert hinders idexirose) Sand contaminated Potential hazard with toxic metallic particles it Pure quartz Potential hazard fSilici SiO^ Method of Operation 1) Unloaded In vacuum svstem Potential hazard L't (.nmpressed air in closed pipe svstent Potcnn.il hn/.ml Belt convevor Potential hazard 41 Clam shell Si Mechanical shovels Gi Work done outdoors Potential hazatd Potential hazard Potential hazard 7) Mann.il indoor work (sweeping, sand cutting! Potential hazard Frequency and Duration of Operation li F.i^ht hr/dav Potential hazard cvrrv dj\ 2i Eight hr/dav -- one da \ /week Potential hazard 3l One hr dav -- v daw/week Potential hazard Reason for Effect Particle* to#) I.tijjc for retention in the hmjv No dtut Dnsn Contains fine* and therefore dusts Ph\*iolo"u;H\ inert mntcnaU Phvstolociralls inert materials Poivmous metallic iIiim Sihcrous dmi Dusts unless con trolled at specific locations Dusts unless con trolled at specific locations Dusts unless con trolled at specific locations Dusts Dusts Natural ventilanon minimize* dint concentra tion Dusts sufficient expo sure U righted expo sure Weighted expo sure 49 1 t i . 1 s - e 3^Sli >. "O c . o> J * JI os u- s* a* tt I I= 5- jil r ,,* -== - s -= 1i :f Elj ijI =- i>* --? = = = il- S2 H ir? ns?* I fjlil s| = i = z BliI =" u * U S '? : - l = Z Z - -- ^ - * =i iMilii = r- 5- = : i :7 |i 7 ^ ?= u= f lllliMI lilt = N! ? C I a 7 - f 2. 11; e 4 t *=s =11i 1 -5 = c ; ; 4111 s= I 2 3i 5it^X='s---i"i|=;i^!E5== I" xc-iz" == -o Iz" = 1 e I 1 r !r - - I i=i =T ^ ? S i - w :=i I 1i =u t-- a- -r " -- a*s -i5 = =f= r 5 z = ill wSz % tf 3 3 "" t* -s 1 - -3 `3r. s v s " r *" * > - 7 .r 2 .2 S a 1 * 3 .*-g C5 =. so .r>.sa ,H ^23? _ 1.1 5 III=! 5I ==-s .IH 1 - * -- i -5 u * 6 s5 f*.2 -- %:i *cr 55 - HIs =*a || 6-5 -s 35. i=.. -r* i! - 2* a? S c * = c i .= ; = -t- SP --= c " _ 1 ill I II 5 SST **< 1 E- 5 = ? --* *sar = = -If 3- = = 5- = .2 -- 3 3 r- c r[rc~- ~= i .1111 a? fc.' .2 i: s -II 5'3-s g w0- -e2x 6-0 * 11 1= s s -r -c sI 2 u-j ; S '.= 2 5 M SC = *1 r.Wi-`1i *. = J'li_n- s al i__ - tc = - 'IK - Cl ~ r i- = 5 5 1Jf --O =1^; cr,, 1 ^ s II i -- VZ -_ v -- -- 2.. t --' -S 3 c - V e *?- | ^ i - -r -- ^ - - ;= C*? i '-1 *" .- "II Ci ---= "I -- =-- ~ = ?..= .= ^ f ! t -r -- w 4 b |i| > i. - -= s *f I- >: =. >= size and perecnlaRcs of the various sizes o f particles, (b) Speeifie K rovity. (c) Am ount of clay nr o ilie r slirl<y substances tained. , (d ) Moisture. 1 , prevent variation in the velocity of (he air. These branch lines should eider the sides of the main. D ust pipes whieh in clin e d o w n w a rd in the direction of flow usually give trouble by clogging. 11. A system should contain as few elbows as possible and they should be o f the longest radius permissible and never less than - - s S a z 6Va .fZl] t 47 4; ^ -- a , a > ^a 6 5 *3 d t. c C *5 -2 a *a a | 47 e d "" -3 d 3 a m 5s^ a --5 0a7 o*- <- 0a40) d4) S 53 2mS C3 E 3 3 | >- * > ** o _S 5, "o..j2M-> S' 2 m -s 6c -- =3 3" U J3 S 5 .-2 5 ** o 1 - 5 - S = c 4l7. .2 :i5r -e S- *5 = e .= c a 93 47 ~. ^w 4: -2 C.I w -_2>>* 4d7 >> == *5 3 "5 2 So " **" a > = -- .a2 a-- --C d' O --55.2 " -- 5 >* a a ---=* c -3 c c t_ - CC 4--7 60 d .3 715 cc a E =e dm W C ad d -Dd a d w .jc V. d . md ma~ e1. -3 2. a -3 aa wS47r cc. m mo a __ 2. -m *3" Ta? T. s a T- w d 2 4C7 2. --2> d c4:) 4. C 2. 9: K > 60 O >v ftt a v- = -=r m2 c mc 5 m4> 6r - -- C -- .J j: . a = - Z -- * *r 2. d a a d _r ZZ*> ad I *Wd _"_3 o ^47 .923 2 07 d Ja2S. *3 a r -c * ^ ^ o > -? U .C5 3 ? O .2 47 _ a O i a & l. dU -- 07 +* K e a ci a2 a d 2 .= 2 E a d cs d tx. X ea .--2 > ** a 1 2 _r -- T ^ aa b * d cs C d " > 2 *a ^ a w a *3 C *u C a c 2 c fs 4L7. 4) -2 d 4m O a O au d -a: e X u 4m a 5 <3 a d c. ao da .B u a M> au 2- d d 2. -3 O a-- e. s 3a ooei OOO'l i>: 60 OOO'OI onon i;? oo ol 3->r.n UOO'l iYvr. 000` U0?'C non'r noo`1 o?: i ij? 60 Ol iiOO i)0ti 3j80 Ol 5j?6 ijgo ol i)S6 i)0fi ij?S ij?8 nu *1 `*0 3O0 : 000 ?! Antiy JO ? .<3u*i34T.d an put 110 ?ro Ol ?n ?0 Ol ?0 0? 01 Ol ST 01 Ol ?r 0? c; SI >1*T JO ? cp0 uou&nvaoooo sc auv or. 01 nsi Xuy a .. .............a,, < ~q. JO wowwop' . iTM0 i 1 p - ' ' c i--------------------------- -------- - uunmou no pinoq )0 imoj Zoinog 01-J OUO\ OUO^ ^aioj ampog JU\- lUIOdMOQ oAoqy ,o?r ioo.m e(V> ,nor. uqiv'D lUlOdAVOQ jAoqy aOu luiod.aQ J .ooc .! n?: 0I-? iptJJCd lapuodsnc AUV ot-? ot-? o?-?r j.j C Id 1J nD 8-9 >0 01 1J 'O . JD ? U "D JO 01 VJ nO c lUIOQ.MSQ d .0081 o-?5: uoncini'J-'Jd 3UU 410i3 uj.uoj: mioq ,xi,\J_ ud loanjumoj Auy lUiod.woQ j .nos n-? sjii13.>||<>3 [rjinjuiuj^ iuy___ iuiod.uoa Auy luiodaQ Auy lutod.wja J 0?8___ jJ aOOS J .008 ?:-o:_ *'J *D WO WI uotinuM uoo ia antaiTVK miarj n maoip; ' uimjo 'K qo \1 -Os MJ J'V lA SOUSialUVUVM^ BOJjmOQ JS-1Q r. a; houvio^ Mtoij - X OmV INBotna^ II-- "HI M ( **.* I 'U4 5 *M ) nrcrrr 6e 13 ***prjiOiH jp, HOUVlijQiog **,3Oi3aT; ff *.*** W, 3>a-- temv agw*. %i* ''C r<a4C*ei aav *A* nc 1 ibc^--r--,) .A.f.r.o-* 7j] 1 ": a DC 73 U= SS" *w2a5 rs" ^c20:3; idr i ( iT rpr. c. j!i~u<= :-?2 :i:g t,:sf <Al/ oC Z Z >*g OBw'JtS l*M "*5 >*'VN fi=c*<;*< o - - o c d o 0,0 Ir; *** Q G t-;AeH C - J,,i8: * *'*'*igi i n81'.'i i / K" fcX; *u ci i r-- H2- 5 It T ciiiponitiiro im p in g e r method. The eflieiem ies were then calculated based on the abo\e conditions. The values given in Table 1 fo r the rem ain- mg collectors were obtained from reported tests made elsewhere and irom such in fo rm a tio n as was available. In s ta lla tio n costs arc asei on axerage conditions. Hue to the wide variations in fo u n d ry purposes. 20. K xam inatiou of the chnractcrislicH of ce n trifu g a l col- lectors A and It o f Table 1 w ill re a d ily show th a t these styles arc ' only suited to coarse m aterial, and are not aide to collect, w ith ' any high degree of eflieieney, fine fo u n d ry dust T heir usual up .n > .. ' liiiviun Ilia'll spi'. ilic K iiiv ily such ;is |n iic silica Kami, lliis ty p o o f i* Is -- = > = = .Z s I =X ~ir* h. S ^r x r u 5? H i II 2 c s III i- fsi :s :?i n- <-h ^ c 1l .S t= * *> E- ~ cS -= . - E =1 = j:! * . .2 e! " 2 S fc 1 si; I c s r =5 6. in = 'Z n I J .5* IS g II c* & S S 51* 1~tt = ' "' : s --~ ^.25 ct r tc. s rr z z CS ' - j *i si-s? rt " * -- i*i-*g| E1 n J*r|.5 - Sr ^ = "- *-J C. S X- = >- -i 1 a- = = if = ~ " w. o -.5- .2 im - t- *r u S lit z1 _ IT =E I.= : = -s C ^ -- TtI Hi 11= !:! 1 i * i-r w i.; jj - Jill 1**2X> ' HI: m i i~ f= I** iZ " - .-~ =-r 55-- === a=s .r- = -- g c u-'-B- g -* c =.-=- -5 I i, HI . s 1' c *- ac S= t: : g = - * z *<r -- i =3 s.s; > r c I T_ E --U >. x tr- 1b e ! j| ?. | 11 = I L" = =-" 0; z 8 !-- i?5~ _ -s = K c -s r 4. i 5 ?= = * <- cc m-f cr -J 'i t -J I V -S Lin.i it s i ii : p !i I . ^_ 8 ^= = ! sj = r* *- _ 8 8 ,|5H -=_ -= 6C 8 C S W w s = M = sP. 1 = 1 - -= c *- d s>4> Sv Eb <y c; fcfl 09 c *" |lC (3 O tc j eo "w3V* (9 ^ 3 -C -- c; W 3 Oa> c. oz < C> e: g X V oo "P a> ^ J3 u .H s 2t> r*>z r cj <o 2HOu Mo 3O .= Z C3 c. C- *a3> <s C5 -- '. aC -- G _Z ^ G. - 15 fc y z a- Z '-- c fee cH f V C^ J^ --. cr - or *- U "2 u > -- -= t. -- . . L. *U *_ 'C w eS W 0} * TZ Z _ CS.t * C t) 4, ^ C. en ~ *" C -- fee 5 ~ .2 5 Ji'sS C -E * J 2 3_ O &* |r = " ;c ez ** w^ ^e" fZt? t s or rr- r* " " - V. . c- *- u 4. cr c J: >-- c -S ^ ^ - ^ i* im *3 G ^ :s = * c C tt K * G -- fe > = r -- J* .5 ^e CJ t - cr e3 H a W .2 U V VV C.3 _g --- fuee 2 t = g J > s 3 5* 'g - fe j; = a> V gh. i-1 |525 -K -r3z CC tft 4; - V .5 w *-- 0> fee *5 C or a e -O c i *^2 =? 3 *2 * c a Cx S .= I **--- --g jwr oo? &3 cr -- sc, fe o -- c ." taa ^ ^ Ca s 5 ^w *c C c ,, Jo -- S Wm0L3. -3 O e^ - C-o ^- o *9*a3 >^5 IM *5 cr W o; 3 C. ^_ 93 2 3 C -- c- > -3 &> r W v | .5 2 S 9,ti =e cC 3 C J5 cr -- i o5 fee T < CA T- t = 5C c--/3 -- 4, -- cCf ---- tcr. - -- ^ < ao-* --c -- O" *- tL --- --*V 3 c e 5 u -3-3 fee fLe.e r -- a2 * S C- 1 J= ou c . .5 o 95 --* 0-- or ^ r: ts cr GG E- 2g __ **" S&S .-~ Z < , & 5 s z a H Z -Gw.2 C "Z E= L- ^ G. 5u O Z O t* ^ --v --5 *- cy; '" *" r* t. a? r c- T *_ - * t G. -- z^ /; cr " C5 ^ ; .- =. t c * 's O .3s >" 3 ^ ^ C. Z ~ ~ s ^ ze JZ M " ` s 1 i;!u. + ^z .2 c ^ ?3 S JZ -"3 4> w .5 .5 = *5 " u! ^ 5a B c ^ ^ J_ er -- --G G tC 0 - L. **- s ~ .2 *" s, " B ~ - a 2 <` Z -G t Ec cr w cr cr --S Gt o*- **= e -G u 2? a. w = * ^^ 5 'C o 0. i .> log s: X ? "g j* < G tr y. M fc H. - '^2 - G 1 c. U *--- It cr >. Z -- *-- cr s --i S 3 c ^>. ^ 4 w- w> C c- G Z G fee 3 > w & = & ^2 -- g S !I- 2 -s "im gfee, -- .S' c c cE 2 s g B w G "3 * * * ^ zi tc 2 < -- G. o T sOD - m c-- .cr. r ^ 3 'C *-- G (O ntario iM 'j.orlnirnt of Ih-nllh. NOTT * Coilea at t l*o This I!t1 prt|*rr v im Con Trot Ion |*r r'len of A K A fit n m >n 11ti In l"r<>ot<i. t *n m h . Control no it H a frtf thinly jiopulAtcri arms. Under Mieli eim dilinns a nilieli higher dust concentration can In: discharged lio m the npi-ialiuns w ith o u t undue pollution of the surrounding atmosphere 43. W eight eflieieneies of dust eolleeim s aio of little value 'Unless considered along w ith n complete analysis o f the dust to he At Power and M aintenance 38. The power requirements o f tlie various dust collecting equipments w ill depend altogether on the particular installation. In ce n trifu g a l collectors of the low efficiency type it may be as low as 1 I I I , per 1000 cu. ft. o f a ir per min. and as high as 3 H P. in' r -- _ x. -- "5 c. u* -- -f ^ ^ e = - r -C = c7 S > 1 ? *" =-' = - c = j: 5= ** i J cr C. s *" J: r '" c c. X-- X (A "C J3 o wft? ? ~-- ar.j C--Z f"t t: "5 > .S: *> <c e Si 5 & v *c ^ "5 w * x$ - c- OC " - e-- be = X >% c C *c=* *s~ .2 i C ~X __ & e be -- 2 BE -- -- 2. C X = g -cj <r * g .s I S -- ._ cr * g ~- tr ^ x ^ ~"* r. ' -- ^"i ZL -- _ - r " -- =c 2- 5 V J| > _ E- ^ 5.H 43 5 * -= X e: = ^ = ce c l C tC ~ -- t -b *5 -- *c- *=" "e 5Kcc. xT s -- S cr . -cu. --c cr ZWcr ---- -c . i. = = c =-C e = _ t* X 5 III c -- a* og . c2 * 7t ^ - X v x x 3 5 --a I 1i2 l!fe llC 53 5 - m= `C s -- 1 -- c C -- t t; 4< * c J- V' = w = 5 . - cr .5 K 2 o 5 t - " rs u C c. cr C e u c c w O 4) C cr (H --v 'E w o g ^j g o-- X r ft cr 3 T. cr > .2 c 1 u v X o 0U3 C5 ** * cr cr CM > U C X cr E cr &j < ^j.. 3 eO Xtfi **->> ~s 2 *ar o 13 03 7 *3 2 2" or * c iz Cm W v O5 be " *o^* --C *4 c 9 tn 9 > fc. a o *J u --CCJ ---S .3-- tcr. - r5 - x c * 'C bC ^ w 09 X -- r = * O s; ,5P 2 e:s cn 9 - S<B Xxx'Sx^ ~ - c^ v; X -Si t2r. z= --r ^2 wcr tbe C. c X1 H a u u *- .t: s = -I - 2& x^ te c Jt ^ fc .rr "c = ri c < ~ -- cr .3 X X 4, X u c. _ r c 7 ^ u = x , ^- ^5v S. tr W ^ H -z a c V - t- = s h wX O =M = 5=2 --c .i u. e 9. 5C. ii E . c be s j? ^ s CL Xbe 3: ^ cr s o ww '"`S -- .!'* x " bo o be-e cc 7 < > -- - g .2 g *a Jr 5 = (/n ln rlo l c|to rln irn t o f Ih n llh N o t i: : T M * p n |* * r v o w p r r H r n h - 'l o t n m -Won <.n fln v . C o n tr o l *n<1 f l o f f l y C o llin a t flu* 1!l n C o iiT riiilm i o f A K A In 2 J. - >> -"E s >> t c be c 3 a ^ bC c s .= -s c a -o be tlt>c s ji CP < *r p cc be ^ e cr ~ C c; ca .2 ^ w .2 K U2 c 2, ce <e s 'o ^ BMH bo a +t-* Cr- m-'2 OiVs *w* *C3VP m2 C -n 232 <ar W JZ C. i6) . D rvz) acr --was o S . 2 z s a -- be -- "o u c- ? 05* ? " 6 o o == S hs 5 ^z CP ca co E-o = zz > VS ~ * . I to < o fs C I s '!!t .2 _* 0J - -- is *" o M o> be 1 IZ j _ 5 *5 be es i jc ct -- c _ C. & ' -- C5 .2 u 2 - j - > " r ^ w cr " C*O ^ CP c CP I .1 1 J *1tfj c r o , r-- .osr -cz J be r 5 cr. C cr -- = C. " - -c"r *--------------- cc cc '.=Z SZ: * c. c C= 2 z c ~ Z ~ q. z" c *" o oc a5 " ) t; - > - 3 o u a a o = S CP 05 u L. g -- "** s t-z .c: ? * c Ce g i- - u 2 C O cr C ^ ec ccrr e"_ - ^ ^ S " fee Cl c -- S c ,c ^ is *cr > _- zT.m CPp ---= & ----' f^e s> * -s = 5=5 5 11!Z U *Z .Z u-- L. w =-- c- -* --~Z tLr CJ 2" ?- = ? tO U -- '" C5 c Z- -z c -s -- C< j ^ - =- E be t"cr -- 'c"r >> cr .3 5 C ^ .Z jf - 2 -- be T rz c jc J 'I 2 5 2z c z; - _ c c. - -- cr > be -- t z -Z ir 2 c > a. : " c -Z v c> -Z *g 4 | | . M J2 -r c - rr g iT c. I r- - c r c? -* ti - C a- -= ^ ^ -- e c r ; ; A- ^ 1 - ~ c -- --C cr- ^CO cr o cp ^ Cj C- > c; - = . c; ^ "3 "O cr u be O u r- be --` > ~ =S . c. CP C feO = ^ cr J 5 = = Z. Z^ "Z -- .-z/ -- Z c.- xff_) "- cCrJ. "3 ~e ,ITr. z: t- _ i *. -- ec -cZr ^cp; / -- -- r. * u~ _Z T (A Cv y -c 1!). I f static pressure is to bn n measure of the i-lfont iveness of a dust fo ile d ini; system, it is necessary im m ediately to specify exactly the shape and size of tbe hood in every p a rtic u la r a p p li- c a tio n ; a procedure which is of course out o f the (piestion. I t would be fa r better to say that the velocity in the duct must be -- SI 'fia -S -S - ' c e= c speed. The iiu llm r Inis seen a num ber o f fuolisli ions;11 |>I i<-;11 of fans and does not. blame tbe fan ninuul ad un r fo r tbese, as very often lie is not consulted, the Tan merely bein;; pnieliased llito u ^ h a puiebasinn aoenl aeenidinjr to a ie<pii^ilion with inadecpiale specifications supplied by sum....... eebanie. Tbe o rd in a ry prnpellor -- * wz i-- c u c. xr. 'Jr. tr C? ^ vc r t - % k. 4>- <s o >% .i Ci M- 1 r ! I I I cj ^cf =.cs ^oS - O 6--0 3sS Bo.>w 5 *"* X S = ^ - C . |.J ^ t'l'J =f " "* " W .z 7 u . *= *^ L - --* .Z 5 -Xw: v s a; -- tc * - t ? ^ T T = r >u1 js t2r - oC * oCs <"f*l -- =e o* z .5 : 2 = i | -v5S . , t i g s g. ~ eoa? ~~-- 2-- s- ~>fee ".eji J S '_ c CP - t - - jr o " - w ^ i> " 5 -i s P fe UVH o O 3*C/-3 Q ,. j r ~ * SB cs os a> . ? -- -g cs) c o V. >, . C3 I I I I ft r**a**ii*>^V^ - *- > ii. 5 _ ^'-= :r - r> c, 5~ u :: y > tc ^ ? -i .c r > 2 aoc. OB e 0> 3 JZ "T * T r i ^ tt 3 :C */ "- sr v: - c: > ~ c c. cr cKr prrrT''''r^* T No source o f dust is too insignificant for attention. ** 9 > ft. >> 3 .I ar < = < i = u --2 .** > -- *. CR O ^ 3 *-- 5 c .ts < 3 s *? -- t- 5SN*aSS s -- *> -3 . "5. *ff = J} 'S I e a = - `5 e -2 " H 3. eg GC 09 3W; VMM cr t -33 C ^ u. -- tr. - fi - a i- u o z a z 3 a I .2 ~ S w c =a _ --^ w3 ~ "3 P > c - 3S. .; x "T > a 3 - ** Co I9 >> .E 4J = w -o %C(ft. S3 "2 -- uaf ._a -= t: 5 aa u O *5 S "3 a * S3 JS u c "* SK v- 5 a o a .3 - '^m j: *c3 ^ _ = - S _ 2 5 u - 3 r c H 3 a +* S- >* c u > j,; c *^- 5 2 > -- 2 m 3 J8 c=r -- . ** _ * fc 3 .-- a flj -c c 2 z:._a t =-25S-_t2: i= '? 5 f "3 ~ x .2 . ~ 5 * ^ 3 -- E- a -T -a w. 3 - Mr 3a ; * <r u V-- _* -- a "c i;' ^ " - a z tc W j= " < > v 3 -- a --a >> .3 ^2 s S 2 ? _ sw .-: = -r 3 C > a = 3 _* 0 5 --"-- - o3 a 4a. J2 t-fl " asOU > * c. 65 . = V i : t X - E SCO la 93 -- ^ 5R a 3 "3 3 CR " " *= -a a >> -- e. i* 3 - >, "Z -O f6-.s-S> _ ^> * 3 u --, - to= ^Ss a: ^ > "5 -a - W a ^ cr -- _o Sr a _ - a E5;"r-S-il-si-? i : = a.0 5r=-- >-o.3 c o au C tc > t C a ^ .2 ^ *<7> 4< v. *w*. > * - - 1 H- i- =r l- = = nl I-H ;in si:f m 7ii i: = :! tH II = Iz Iz I-- r j: w ?! 1 z O Ctoo 3 to Q O a: Z O to 3 a Se=5C95^'. v - - " ~.*- - -- i. 1: -- Z. |I r= s I/ ii i: 3~ 5;c 1 = . r = i S3! ill IN Il = = ~ IN =i ! = * 5 ii:= * 1 ;f i > " * O= 2 I - " s z / = I U : Mf H i " ^ jfi* 3 r r s .= 2 = = '7 -r = - = --= i- ~'i i* : *r 4 lssi ; "- -z. -- -- f zis-l* Mill 1 - i J r. i -= i = h: = ; l_ = r -rs ; l =Z =1 -fii IJ i =1 -iM ~ r = -: -- i i=_ ?35 =t = ! : j- * - -3 = si I H z z. - ~ ;C: i=i i H- == : 5 \\U M. ?5 iil ` ii 5 * . << 17. ?i = = = : I {fit ill! II;i Ui*u :l!i i !ili! I illtup3 -- ? = H.ii f = fillm = = i li ^ 11 'e*uh* I r * ll- ' ! =5 ii3 3 u i = . .> := z X A >. I: = : 1; -1 = -sf hi ^ z I - = -J iif ^nli f = 5 ti UP m i = 1s" Hi till= - i> -- r" ={= "T- -5= -a= == f i i Hi l- _ = - : iJ- liMi li|: mn T S 1-- z > ^ 5 5 -r njj ~i, r- r ; - i, ; - 5 : _I i 3- i- = = ' ! s s lit; ; . - 1= - - i1!1 ii !i: ! I^ Iti; - : : =~2-3= =;]Li 1= 77 -1 == .77 M- ^-- T : I] 1 =--t hi =r =1 = !i = f I 5 = = i=-"i 5 Iff 4 1r i i= i;n- i / i*4Ji i >= r : fI =!= HIM 5-7. Jtii f5nh =is=I= i'Hi iIHi J = i ' 3 :f : HH 3 = j; : ; 2T 3_ .:- - w i Jill I li- ! U!5 3 .4- - ; - ; i T s - - ii f f = - i X 1 :3 lil I ix * = = hi i 1 ii-lit =' = liUU II S $ I 5 i. = 3-3 t - >. ui H|! = -= 1. s " > ? j si^I"\1r- itii I il III i 7. I ;un s u rr M r. la llt h . in h is iI im nsslm i o f Mm> h iI'Ji s I, w iis r c fr iT in u In ^ iik s rx p o v im * In iln s l. In a tfro iil m any liiM m u rs u l i n r iliis t Is i\Mh|> l l i r r r Is Mm* 1iisl iiN n. I !< ii'H Ih in k llia l aiivnm * fa m ilia r \v ||It flit s iiI |i * ( u o iilil n ii'liT fn k r in say llia l llirn * u ;n no li*;illIt h tm m l lu ran^i* Ho y * o iiM tm l sr<> any *ltM . p a r lli n la i ly I f ilir y know llia l (lie ' \ American jjfounbcpmen'* association Tentative Recommended Good Practice Code and Handbook on the Fundamentals of Design, Construction, Operation, and Maintenance of Exhaust Systems m Developed by A. F. A. Industrial Hygiene Codes Committee and Approved by the Board of Directors cv as a Tentative Code of Recommended Practices for the Foundry Industry Price per Copy $4.00 AMERICAN fOUNDBYMEN'S FOREWORD In 1935, *4ien the Safety and Hygiene Section of the A.r.A. was instituted, the Board of Directors, realizing that there was urgent need of having the Industry develop foundry process codes as promptly as possible In order to have recommended uniform practical information available for the industry, authorized the formation of an Industrial Hygiene Codes Committee. The Board of Directors In listing the various fields of activities for this connlttee, presented the following objectives: (a) "To assist In the standardization of dust eliminating equipment and Improvement of shop operation conditions in the foundry Industry." (b) "To promote standards for dust elimination and control equipment in cooperation with agencies of manufacturers of such equipment." The industrial Hygiene Codes coannlttee was then formed, and made a su-vey of the needs of the Industry. The Connlttee decided upon the following fields for first consideration In preparation of recommended practices. Additional fields will be undertaken as codes for this group are completed. 1. Grinding, Polishing and Buffing Equipment Sanitation. (Tentative Code published as A.F.A. Preprint 36-2B - 2nd Edition) 2. Testing and Measuring Air Flow In Exhaust Systems, (Tentative Code published as A.F.A. Preprint 36-27 - 2nd Edition) 3. Fundamentals of Design, Operation, Construction and Maintenance of Exhaust Systems. (Tentative Code published by A.F.A. 4. Metal Cleaning. 5. Non-Ferrous Melting. 6. Foundry Industry Code. 7. Foundry Partings. e. wood Working Machinery Exhausts. The Committee, In presenting Its recommended practices. Is Interested In-serving the needs of the foundry Industry, particularly the smaller foundries *iere they do not regularly erploy an engineering staff. Furthermore, the Committee has as one of Its objectives the obtain ing of 'uniformity In the safe guarding of processes and operations. It Is believed the engineering data Included In these tentative codes of minimum re quirements will enable the foundry Industry to solve their ventilating problems at minimum cost, consistent with good engineering practice. 11 INTRODUCTION This tentative code of recommended good practice covering the fundamentals of design, construction, operation and nalntenance of exhaust systems has been developed by a coralttee of the American Foundrymen's Association to cover the necessary engineering data required for design lng and installing exhaust systems In the gray Iron, malleable, steel, and non-ferrous branches o the foundry Industry, and has been approved for publication by the Board of Directors. Many foundries have, m addition to casting cleaning departments, pattern, machine, and maintenance departments which are considered integral parts of the foundry operation. Also In many Instances, there are additional departments wherein further operations are carried on In the processing of materials where this code may be applied. The purpose of this code Is to provide the Industry with sufficient engineering and construction information so that exhaust systems may be properly designed and installed, and is therefore recommended as a guide In furthering good practice. The Technical Committee, which prepared this code, known as the American Foundrymen's Association Industrial Hygiene Codes Committee, is as follows: Chairman, J. R. Allan, International Harvester Co., Chicago, 111. R. J. Aldrich, Sloan Valve Co., Chicago, 111. F. H. Amos, international Harvester Co., Chicago, 111. C. P. Culon, W. W. Sly Manufacturing Co., Chicago, 111. . E. Blrkland, Crane Co., Chicago, 111. Carl F. Larsson, American Air Filter Co.f Inc., Chicago, 111. S. McMullan, Western Electric Co,, Cicero, 111. J. G. Llskow, Claude B. Schnelble Co., Chicago, 111. Nathan Lesser, Deere & Co., Moline, 111. R. W. McCandllsh, Research Corporation, Chicago, 111. John F. Tobin, American Blower Corporation, Chicago, 111. Secretary, E. 0. Jones, American Foundrymen's Association, Chicago, 111. * Conferees: G. A. Kluge, Central Blow Pipe Co., Chicago, 111. J. M. DallaValle, united States Public Health Service, Washington, D. C. L. C. Stokes, Department of Labor, State of Illinois, Chicago, 111. C. S. Anderson, Belle City Malleable Iron Co., Racine,' Wls. L. S. Peregoy, Slvyer Steel Casting Co., Milwaukee, Wls. J. 0. Houze, National Malleable k Steel Castings Co., Cicero, 111. 12 l j I I 1 | 1 , f 3 ^ 3 . .--v-:/v- - . -'; v ........... LiSL'^L .. . Section V: Application of Exhaust Systems (A) Functions of an Exhaust System. Exhaust systems shall be Installed for the removal or all matter such as dust, dirt, reruse, runes, vapors, gases, and mists, that, constitute a health, sarety, rire, or explosion hazard or nuisance, and such exhaust systems shall catch such dust, dirt, reluse, rumes, vapors, gas.es, and mists, at the point or origin and berore they become dirrused into the general atmosphere or the work place or room. The exhaust systems shall convey such matter collected to some saTe place Tor disposal and rurther provide Tor the discharge or the exhausted air In the manner provided Tor in any or the recommended good practice codes or the American Foundrymen's Association or by lav*. NOTE: An exhaust system shall not be conrused with a ventilating system, which type or system has to do with the general atmospheric control and ventilation or a work place or room. The primary consideration in designing an erflclent exhaust system shall be that or pro viding hoods or enclosures or other devices that efroctlvely catch the matter In question and prevent Its dirruslon into the work place or room. When detailed engineering Information is given In any or the American Foundrymen's Association recommended practice codes, or in requirements specified by law, as to the exact de sign features for hoods, enclosures, and devices, such designs shall be followed, but In the absence of definite design Instructions, the following factors shall be considered and used In developing hoods, enclosures, and devices for catching matter. (.B) Characteristics of Matter to be Exhausted. U) General: The characteristics of matter to be exhausted vary with types of operation, process, or equipment used. Such matter, whether In the form of solids, liquids, or gases which, due to their shape, density, or through kinetic energy Imparted to them by some force may remain In suspension In the atmosphere for a relatively long period of time before settling to a resting place by the force of gravity. (2) Size of Particle Matter: The length of time that particles of matter remain In suspension In the atmosphere depends upon the particle size, shape and Its specific gravity. The smaller and the more microscopic the particle, the slower the rate of settling In air by gravity due to the relatively large surface area compared to weight. The chart of "Size and Characteristics of Air Borne Solids* on Figure 2 shows the rate oT settling In FPM for various sizes of spherical particles with a density of 1, the laws or settling, comparison of particle size, surface area of particles, and the like. As a general rule, the particle size of hygienic Interest are those under 10 microns In size (1 micron - 0.00003937"). Particles over 10 microns in size may not be of hygienic interest but shall be exhausted because they may cause some other form of hazard and at the least, they are a nuisance. (3) Action of Oases. Gases including vapors when liberated Into atmosphere are acted upon oy gravity. Such matter having a density greater than air will descend, whereas with a density less than air, It will ascend. Gases and vapors escaping Into atmosphere at high temperatures, may have a density greater than air at atmospheric temperatures, but because of expansion of volume due to heat, are lighter than air until cooled to the surrounding air tem perature, by which time the gases and vapors will have permeated to a considerable extent into the atmosphere. Heavier than air gases and vapors, particularly If released near atmospheric temperature, will fall by gravity and concentrate in more or less concentrated pockets in relative ly still air. When dealing with gases and vapors it shall be necessary to determine their density ln order to estimate their probable direction of travel when released to atmosphere. 17 (4) Diffusion of Matter In Atmosphere, When natter in the fora of solid or liquid particles, or In a gaseous state, is released by some force or cause, the tendency is for such matter to diffuse and permeate into the atmosphere. The condition of air not being In motion is rarely encountered. Air Is usuallyIn motion and Is motivated by drafts from the outside wind pressures, heat radiating surfaces, ventilating equipment, moving parts of equipment, occupants moving about, transporting of materials, and many other Influencing factors. The degree and speed of diffusion of matter Into atonosphere Increases with the magnitude of air movement. Matter that is released to atmosphere under pressure, or by dynamic forces, will diffuse to a greater distance at an Initially higher speed, depending on size, shape, and density of the particle matter, but the microscopicsizes will lose their Initial velocity In a very few inches of travel. Oases and vapors alsodiffuse at a slow rate. Theoretical specifications for the diffusion and permeation of matter In atmosphere In work places or rooms, are of little practical value beyond a knowledge of the tendencies, fthen solid, liquid, or gaseous matter Is visible to the eye, a study of the diffusion tendencies shall be observed to determine their direction and speed. When the matter has little or no visi bility, smoke bomb tests should be resorted to rtilch will give some Idea of the directional tendency. It should be borne In mind that the smoke particles may be of different size and density than the matter being studied. (5) Prevention of Diffusion of Matter. Whenever practicable, the area of generation or cause of matter escaping to the atmosphere, should be surrounded by an exhaust hood, enclosure, or device that will prevent the diffusion of the matter Into the atmosphere of the work place or room. When such exhaust applications are not possible, exhaust hoods shall be located as close as possible to the point of origin of the matter escaping so that the air flowing towards th* hood opening will have Its maximum effect In directing the matter Into the hood. If the nature of the operation or forces Involved give the matter decided directional tendencies, the hood opening shall be located as near In the path of travel as possible to take full advantage of these ten dencies. The Influence of alp movement from surrounding forces when such air movement pre vents the proper functioning of the exhaust, hood, enclosure, or device catcrflng the matter to be exhausted, shall be properly shielded or baffled from the operation to permit the proper functioning of the exhaust equipment. tC) Enclosed Processes. Enclosed processes such as tumbling barrels for milling cast ings, abrasive cleaning rooms, cabinets and barrels, sand mullers and mixers, and the like, are relatively easy to exhaust and the dust is prevented from escaping and diffusing Into the general atmosphere by keeping such enclosures under negative pressure. Due cbnslderatlon shall be given to providing for the necessary Inlet of air Into the equipment, and such air Inlet shall not be less in cross section than the area of the exhaust pipe serving the equipment. (D) Codified Hoods. Hoods which are code prescribed as to the shape and size, and minimum branch pipe air velocities such as grinding, polishing, and buffing hoods, catch the particles of matter of hygienic Interest but may not always carry heavy particle sizes with the flow of air Into the hoods because of the high inertial effect imparted to them by rotating wheels and belts. Such hoods have been developed to their present standard from years of experience and adaptability to the Job. Such hoods shall be made to not less than the minimum requirements as prescribed by the recommended good practice codes of the American Foundrymen's Association or by law. (E) Partial Enclosures. Such operations as are conducted Inside a partial enclosure, diere the work Is between the point of exhaust and the operator, and the operator 16 positioned at the face or Just outside of the one opening Into the enclosure, are readily exhausted. It Is only necessary to maintain a flow of air Into the enclosure openlrlg as may be prescribed for the particular kind of matter to be exhausted; but In no event shall the average face velocity be less than 100 F.P.M. and shall be greater, depending on specific requirements or If there is a code requirement specifying the velocity for the particular operation. 18 3 1 ) I hi For large and complicated enclosures such as are used In connection with continuous conveyor systems and the like, Where the product being worked on passes through one side and out on the other side of the enclosure, more'study ie required to determine the amount or quantity of air flowing Into the various openings of the enclosure to prevent the escape of matter Into the general atmosphere. If the enclosure Is exceptionally long and more tunnel-like In shape, and ttie operator works along one side of the enclosure, It is usually advisable to admit air fr openings through the side and If possible about the breathing level so that the operator always has fresh air flowing past his head towards the work and the exhaust. In these more complicated enclosures, the average velocity of air shall be Increased to compensate for the unequal exhaust distribution, and shall not be less than 150 ft. per minute for the aggregate of all openings depending upon the specific requirements. (F) Operations Outside the Exhaust Hood. Every attempt shall be made to perform the operations within an exhausted hood or enclosure to prevent the diffusion of matter Into the gen eral atmosphere; but If, because of the size, type or nature of the work or operation, It Is physically or economically Impracticable to provide such safeguards. It Bhall be necessary to provide exhaust hoods as close as practical to the operation. Some of the more Important elements that shall be considered In designing such hoods are: 1. Effective Range of Air Velocity altering an Exhaust System. i.lr tends to flow towards an exhaust hood from all directions and the Immediate effect on the general atmosphere is that a local zone of air somewhat resembling a spheroid In shape, moves constantly into the exhaust hood opening. The Inflowing velocity of the air Into the hood rapidly decreases away from the face of the hood, hence, it Is essential that the exhaust hoods shall he placed as close as possible to the point to be exhausted. The shape of the face of the hood shall conform to the general shape of the area to be exhausted and shall be large enough in area to catch any matter liberated by the operation that would contaminate the atmosphere. Smaller size objects to be exhausted In front of ahood do not divert to any extent or Influence the air flow into the hood but large objects, such as tanks, and the like, distort the air flow and allowances shall be made for such distortion so that the required air velocity Is provided at the proper place. The contour lines of velocity In front of any round exhaust pipe, with no large ob struction In front of It, shall be determined graphically from the charts on Figure 3, for either pipe with or without flange. NOTE: The graphs Illustrate the Improvement In higher velocities In front of a round exhaust pipe by using a flange. The contour lines of velocity in front of exhaust hoods with no large obstructions In front of them, shall be based on the velocities at the hood center line or axis by the formula: 9 V = 10X2 A Where V - Velocity FPT1 at X Q = CFH flowing Into hood X = Any point X distance in terms of feet on the centerline or*axlB of hood A Area of hood face In square feet The velocities to the side of the hood centerline or axle may be approximately de termined graphically by plotting contour lines of equal velocities, using constants in terms of hood axial dimensions patterned after the contour lines shown on Figure 3. The volume of air entering the hood shall be determined by the formula: Q * 10VX2 AV If one or more sides of a hood are extended as for a hood set on a bench or floor, or located against a wall, the volume Q may be reduced 2056, as compared with a hood that is open 19 99 m mams* w ifsa&smssmm all around the periphery; and the velocity at any point Z under these conditions vrili be appro ximately the same as Tor the velocity calculated for the hood open on all its sides. The contour lines of velocity In front of exhaust hoods, with large obstructions in the path of the inflowing air, shall be studied graphically by making sketches to scale of the hood and obstructions and approximating the velocity contours beyond the hood according to the following figures most nearly approximating the condition: Figure 4, showing a hood located on a table, bench, floor or acalnct c wall or the like. Figure 5, showing a hood and obstruction with approximate end to side ratio of 1:2. Figure 6, showing a hood and obstruction In which the length is great compared with the side. 2. Velocity Required for Catching Matter. Matter liberated beyond an exhaust hood is difficult to catch. If the matter particles are produced so that they are thrown dynamically in one general direction, as from a wheel or belt, the hood shall be located In the direction of the path of the particles, otherwise excessive velocities are required to overcome the kinetic force of the particles of matter, or they are not diverted from their path of travel at all. The neces sary velocity required at the point of liberation to catch the particles of matter shall be care fully determined. For economical and practical results In the final Installation, small testing hoods should be tried out to determine the actual velocities required to accomplish the desired results. (Q) Ventilation of Heated Masses and Equipment. (1) General - Heated surfaces whether of masses of hot material or furnaces under temperature cause definite movement of air vertically and If vents In such heated surface^ emit products of combustion, as from furnaces. In addition to the heat caused by radiation from the surfaces, the air movement Is accelerated. Such heated surfaces need not be equipped with exhaust systems provided there are no toxic or Irritating dust, fumes, vapors, gases, or harmful concentration of carbon monoxide present. Exhaust systems shall be Installed to exhaust all heated surfaces causing a toxic or Irritating concentration of matter In the room atmosphere. The removal of excessive heat or non-toxic fumes and gases may be accomplished by general ventilation or natural draft hoods, or stacks, vtfilchever method suits the general condi tion. (2) General Ventilation Applied to Heated Surfaces. The vertical movement of air Induced by heated surfaces affords a natural means of ventilating a work place or room provided provisions are made In the architectural design of the building for the escape of the heated air, or non-toxic or Irritating fumes and gases through roof ventilators, monitors, skylights and sash, or by mechanical ventilators and shall be not less than 2 cu. ft. of air per minute for each square foot of floor area. The floor area Involved shall be considered the gross area of the floor embracing all of the heated surfaces. In the case of isolated heated surfaces, the floor area to be assumed shall not be less than ten times the projected floor area of the heated sur faces. (3) Natural Ventilation Applied to Heated Surfaces. Natural draft hoods and stacks when applied to heated surfaces shall have the hood fit as closely to sides of the heated surfaces as possible; but If the hoods are used as canopies over the heated surfaces, the edges of the hood shall project out beyond the heated surfaces 1* for each 2* distance from the face of the hood to the top of the heated surfaces. The stacks shall have an area of not less than 10* of the projected floor area of the hood and the total bends In the stack from ltB connection to the hood to the outlet shall not exceed lBO; and no single bend shall be more than 90. When total bends approach 100 In the stack, stack height should be increased to obtain greater chimney effect to offset resistance caused by the bends. 20 (4)achaust Systems Applied to Heated surfaces. Where exhaust systems are necessary in connection with heated surfaces or hot objects, to carry excessive heat, toxic or irri tating matter, the hoods or enclosures shall fit as closely around the heated surfaces or objects as practical. Wherever required or possible, the sides of the hood or enclosure should extend downwards to cover the sides of the heated surfaces, allowing a space between the heated sides and the sides of the hood to provide a space for the flow of air. Air shall be admitted to the hoods or enclosures by means of openings. The velocity of the air flow into these openings must be sufficient to prevent the escape of hazardous matter. For calculating the volume of air to be exhausted from the heated surfaces. It Is first necessary to determine the rate of maximum heat Input Into the object to be exhausted - If It is a furnace, heated tank or vat, In terms of BTU per hour. This can be ascertained from the amount of fuel used, whether It is solid, liquid or gaseous fuel, electricity or steam. Next, the final temperatures of the discharged air shall be considered, taking Into account the effect of the heat on the fan and fan bearings. If the hooded parts and pipe ducts are In close proximity to people working, the effect of radiant heat from the hoods and piping shall be considered and reduced final temperatures of air discharged should be selected so that radiant heat will not cause unbearable conditions. Air movement will not remove radiant heat and the objectionable radiant heat can only be reduced by cooler surfaces involving the handling of the larger volumes of air. When the heat input In BTU per hour Is known and the final temperature of the air discharge selected, the volume of air to be handled per minute by the exhaust system shall be determined from the curve on Fig. 7. From the side of the chart or ordinate, find the BTU Input per hour and read crosswise to the Intersection of the curve of desired final temperature and then down to the abscissa to find the volume of air to be exhausted. The volume of air to be exhausted is In terms of standard air and shall be corrected for final temperature In determining the fan and pipe sizes. If It is necessary to exhaust a heated mass that has been removed from Its source of heat supply, each .Individual Job shall be calculated Independently, taking Into account the kind of material, final temperature of material, specific heat of material, surface area, character of surface, volume of air moving around material, desired cooling rate and final exhausted air tem perature. If the products of combustion of any furnace are exhausted by an independent stack, the heat contained in the products of combustion should be deducted from the heat Input Into the fur nace when ventilation of furnace proper Is being computed. (H) Removal of Hot Gases and Fumes. When any type of furnace or oven equipment emits toxic or Irritating fumes and gases, hoqds shall be provided where such gases or fumes are discharged for the removal of such matter from the general room atmosphere. In the case of Irritating, but not necessarily toxic gasesand fumes, natural draft hoods and stacks may be employed. Where toxic material Is present,exhaust systems shall beInstalled. 11) Natural DraftHoods. When draft hoods are Installed for the removal of gases and fumes, the hoods shall enclose or cover all of the area at the point where such gases and fumes are liberated from the equipment producing them. The area of the natural draft stack shall not be less . than 10S of the projected floor area of the hood; and the total bends In the stack, from hood to the outlet, shall not exceed 180 and no single bend shall be more than 90. When total bends approach 180 m the stack, stack height should be Increased to obtain greater chimney effect to offset resistance caused by the bends. If gases and fumes are liberated from the equipment under considerable pressure so that natural draft will not overcome their directional tendencies, then exhaust systems shall be Installed to positively remove such matter. (2) Exhaust Systems for the Removal of Oases and Fumes. Whenever any piece of eaulpment emits toxic or harmful Irritating gases and fumes, such matter shall be removed by ex haust systems. The directional tendencies of the gases and fumes escaping from ttie equipment shall 21 m tzrw 11 i hhp**'.! ro. i;usa ujwi'lii ju nfD B--n--n ^-- be carefully studied and Oie volume of such matter flowing out of the equipment shall be deter mined. The hoods shall be designed to receive all of such matter and the minimum volume of air to be exhausted shall.not be less than twelve times the volume of gases and fumes emitted from the equipment. (I) Removal of Oases. Fumes and Vapors Heavier than Air, Many gases are heavier than air with a result, due to their greater specific gravity, will fall rather than rise and wfien diffusing Into the general atmosphere, will concentrate In the air near the floor or breathing zone. The character, specific gravity and the tendency of these gases to fall or to accumulate In pockets, shall be determined. In exhausting fumes and gases heavier than air, the exhaust hood shall be located at or near the floor In order to remove the gases with the least amount of travel. The volume of fumes or gases produced shall be determined and the amount of exhaust provided for their removal shall not be less than four times the volume of such heavler-than-alr fumes or gases. (J) Air Curtains. Certain operations may produce dust, gases, fumes, or vapors taich cannot be exhausted by any type of hood or enclosure and In some such Instances, the air curtain principle of catching hazardous matter may be adaptable. A relatively thin continuous sheet of high pressure air forming a curtain which is blown out of a pressure box, shall surround the opera tion on the open sides to be exhausted and directed toward a receiving hood having sufficient ex haust to remove the air discharged from the pressure box plus such air as Is Induced Into the pressure stream. The distance from any point of origin of dust, gases, fumes or vapors to the inner sides of air curtain should not be less than eight Inches and If the object producing the dust, gases, fumes or vapors Is very hot or If there is considerable steam or other fumes tending to cause considerable agitation of air within the air curtain, the distance from any point of ori gin to the Inner sides of the air curtain shall not be less than twelve Inches. The air required for the air curtain may be recirculated by obtaining the required volume of air from the air exhausted from the receiving hood. Figure 8 shows a diagrammatic outline as to how the*air curtain functions and designing Information is given for the proper functioning of air curtains. (K) Exhausting Dissimilar Matter. No dissimilar matter shall be handled through one exhaust when the intermingling or contact of one type of matter with another type of matter will cause a fire or explosion hazard either In the piping system, collection unit, or air flow pro ducing equipment. Operations generating sparks such as from hot materials or from grinding wheels, shall not be consolidated In the same exhaust system that also handles Inflammable or explosive matter. (L.) Dlaslmllar Velocity Requirements. No exhaust syBtem should be designed with the Intent to handle a number of branches which may have a wide variation In velocity requirements be cause the system will require sufficient power to handle the highest velocity branch pipes which is far greater than required for the lower velocity branches. * E E E E 22 Code of Recommended Good Practices for -* * k V''.\ >. "S" ' r iV. f?k A-J->rrt>. iTV |RT. ?.* ' s, - ';. " ^':+r^}Sllp3t /* ' ; .- -1-,;y ...;. . v:2f ... .* - r: r'-v. .' ; V.,'AV5>';' \ ` > s '..* .* . T- ' *' Hist. TS 236 . A67 1939 C. 2 ! i ' 'i ' y- " " >( w* AMERICAN FOUNDRYMEN'S ' -" r ' .. SOCIETY + -w .m ' AlMERICAN FOUNDRYMEN'S- . . ... SOCIETY ;i * KJ; St * * ` INTRODUCTION Thia coda of recommended good practice for mtal cleaning sanitation baa bean developed by a committee of the American Foundrymen'a Association to cover the neces- aary engineering data in the dealgn and operation of metal cleaning units and prooeaaea aa well aa apeciflcationa for personal protection of workera engaged in metal cloaning wherever auch operationa may be carried on in the gray iron, malleable, ateel and non- ferrous branehea of the foundry industry, and has been approved for publication by the Board of Directors of that Association. Many foundries have, in addition to casting cleaning departments, pattern, machine and maintenance departments which are considered Integral parts of the foundry operation. Also, in many instances there are additional departments wherein further operationa are carried on in the processing of materials where thia oode may be applied. The purpose of this code is to provide the industry with sufficient engineer ing, construction and operating information ao that safe practices may be followed and exhaust systems may be properly designed and installed and the proper personal protec tion equipment provided, and is therefore recommended aa a guide in furthering good practice. The technical committee which prepared this code, known aa the American . Foundrymen'a Association Industrial Hygiene Codes Conmlttee, is as follows: Chairman, * J. R. Allan, International Harvester Co., Chicago, 111. R. J. Aldrich, Sloan Valve Co., Chicago, 111. F. H. Amos, International Harvester Co., Chloago, 111. C. F. Qulon, W. W. Sly Manufacturlng Co., Chicago, 111. E. E. Blrkland, Crane Co., Chicago, 111. Carl F. Larsson, American Air Filter Co. Inc., Chicago, 111. S. McMullan, Western Electric Co., Cicero, 111. J. 0. Liskow, Claude B. Schnelble Co., Chicago, 111. Nathan Lesser, Deere A Co., Moline, 111. R. W. McCandllsh, Research Corporation, Chloago, 111. John F. Tobin, American Blower Corporation, Chloago, 111. Secretary,E. 0. Jones, American Foundrymen'a Association, Chicago, 111. Conferees,C. S. Anderson, Belle City Malleable Iron Co., Racine, Wls. George Boesger, W. W. Sly Mfg. Co., Cleveland, Ohio W. E. Clayton, Central Chemical Dlv. of Wilson & Co. Calumet City, 111. 0. L. Coffey, Whiting Corporation, Harvey, 111. John W. Dammers, 0. S. Blakealee k Co., Cloero, 111. J. 0. House, National Malleable it Steel Castings Co., Cloero, 111. Qeo. M. Howard, N. Ransohoff, Inc., Cincinnati, Ohio M. Marean, E. I. du Pont de Nemours it Co., Wilmington, Del. Deceased 6 Section IV: Cleaning Procea** (A)-OENERAL: There are numerous methods or processes for the cleaning of metal parts In use today. This code prescribes engineering recommendations for the operation of such equip ment, control of health hazards involved, and makes definite recomnendatlons in connec tion with some of the more pertinent accident hazards. The hazards Involving health aai safety with any type or process of cleaning must be recognized and thoroughly ualerstood in order to provide the proper kind of installa tion and for iafe operation. (B)-METHODS OF CIAHINO: The cleaning of metal parts is accomplished by one of the following five methods! 1. Mechanical cleaning which Includes such equipment and methods as tumb ling mills, abrasive blasting units,hydraulic pressure methods, grinding, brushing, soraplng and chipping. 2. Burning, which consists of the removal of surface matter by the applica tion of heat or flames; 3. Solvent oleaning, which consists of the removal of matter from the surfaoes of product by putting such matter in suspension, solution or dissolving the substanoe which holds such matter to the surfaces; 4. Chemloal cleaning, whloh consists of the removal of matter from the sur faces of the produot by saponification, omulsifioation or chemical reaotlon between the chemical oleaner ami the matter to be removed; and 5. Electrolitlo cleaning, either by the anodic or cathodic methods which oonslsts of accelerating the aotion of alkaline or add cleaners by the use of electrlo current. (C)-SELECTION OF PROPER CLEARIN0 METHODS: Every type of product to be cleaned should be studied to determine the best method to clean the matter from the surfaces, depending on the kind of matter to be re moved and the degree or standard of oleaning desired. Matter to be oleaned from the surfaoes of a product is divided into the follow, ing four classifications: 1. Inorganic insolubles, which includes oxides, sanls, sulfides, dirt, dust, chips and abrasives. 2. Oils, which include oils that have not been changed chemically such as untreated animal, vegetable and mineral oils. 3. Treated oils, waxes, greases and soaps which include sulphonated and chlorinated oils and waxes, treated animal, vegetable and mineral waxes and fats, metal salts of fatty acids and greases. 4. Miscellaneous chemical compounds which includes fatty acids, inorganic acids and other chemicals and matter encountered in metal treatment. Moat metal cleaning operations present health or accident hazards, varying in degree and intensity with the type of cleaning methods employed. These hazards depend upon the toxicity of the cleaning medium or matter removed, the effect of the cleaning medium on the akin and eyes or through inhalation, the ability to protect the operators nd others from direct oontaot with the prooess, the isolation or enclosing of the process and the like. 9 In addition to possible hazards from the cleaning operations, other hazards may prevail, particularly in solvent cleaning because of the evaporation of the solvents them selves from the surfaces of the product during cleaning or in the handling of the product after cleaning. (D)-KNOWLEDGE OF HAZARDS: 1. GENERAL: A complete study of the health and accident hazards shall be made to determine all the direct or indirect hazardous exposures or effects for whatever cleaning practice may be employed. The toxic properties of the cleaning medium or the matter to be removed from the product shall be definitely determined. 2. DUST HAZARDS: The mechanical cleaning processes usually produce dust, much of which may be comprised of minute particles which, unless controlled by exhaust systems, may contaminate the general atmosphere and if of a toxic nature, may cause an occupational health hazard through inhalation, or may consti tute a fire or explosion hazard. Such hazards exist if there are silica, certain oxides and the like, present. Dust hazards may not only exist in the actual cleaning operations but may also be present in the disposal of the refuse. 3. CHEMICAL HAZARDS: The cleaning of product in solutions, solvents or acids, presents in many Instances a very definite occupational, health, accident, fire or explosion hazard. Not only do some solutions and acids employed constitute a definite hazard in the raw state but some may through decomposition through the action of metals, water, heat and the like, cause secondary substances that are hazardous and even deadly in their effect. Due to the many possible compositions, solutions, solvents and acids available for good results in metal cleaning, a close analysis shall be made of the solutions or acids to be used and the effects of their decomposition. The health hazard due to the use of same cleaning solutions, solvents and acids varies tremendously. Some only produce skin irritations resulting because of the removal of the natural oils from the skin while others cause irritation due to direct contact. Other solutions and acids cause burns on the akin or may poison those coming in contact with them due to their toxic properties, by absorption into the skin. Some solutions, solvents and acids cause occupational diseases through inhalation. In certain types of cleaners the fumes, mist or resulting gases are very toxic. Certain persons are hypersensitive to some cleaning solutions, solvents and acids, and therefore operators should be carefully selected for such cleaning operations by a proper medical examination and observation. 4. SELECTION OF CIEANING EQUIPMENT: A thorough study of every cleaning operation shall be made and only such equipment or practices shall be installed or inaugurated consistent with the quality of cleaning desired that can be operated and maintained in a safe manner from all hazards. 10 5. INSTRUCTIONS FOR OPERATING CLEANING OPERATIONS: All cleaning equipment shall be operated and maintained to minimize hazardous exposure. Whenever any hazard of any kind exists, operators and others having to do with the process shall be Instructed in their duties and in the care of the operation. Instructions shall include the dangers in volved and in the use of whatever personal protective equipment and first aid practices that are to be followed. In the absence of better Information and instructions, the recommend ations of the equipment or cleaning medium vendors shall be followed. 6. REPAIRS AND MAINTENANCE: Close supervision and maintenance of cleaning equipment shall be in effect. Such supervision not only is an economic problem but will minimize exposure to health and accident hazards. Some person or department shall be made responsible for the strict supervision over the carrying out of instructions for the safe operation and for the repair and maintenance of all such equipment. 7. ACCIDENT, FIRE AND EXPLOSION HAZARDS : Only a few accident, fire and explosion hazard recommendations are enumerated in this code. Information 1s available on this subject from a number of recognized sources and use should be made of all such information. 8. PERSONAL PROTECTION : Whenever any cleaning process requires the operators and others to wear personal protection equipment or clothing, auch equipment and clothing shall be provided and worn during exposure to hazards. Instructions shall be given to those required to wear such equipment and clothing and supervision shall be maintained to see that such equipment and clothing are properly used and kept in a clean, hygienic and safe manner. Section V: Alkaline Cleaning Processes (A)-GENERAL DESCRIPTION OF PROCESSES: Alkaline cleaners are used for the removal of oil and grease by either emulsi fication of the oils or saponification of the fatty acids in the oils or greases and for stripping off of paint by attacking the oil in the paint or Japan, which will re lease the pigments on the surfaces and as neutralizers after some pickling operations. There are many alkaline solutions, either straight or compounded, used to accomplish specific results and these vary with the kinds of metal to be cleaned and the nature and standard of cleaning required. The cleaning aolutlons are heated and in some cases combine either the anodic or cathodic electrolitic processes for certain characteristic results. (B)-HAZARDS INVOLVED: The accident hazard is quite involved in the use of alkaline cleaning solutions because of the danger from burns to the eyes and the skin of operators. These solutions remove the natural oils from the skin and dermatitis may result. The health hazard is not particularly involved otherwise, except at the time when compounds are added to the hot solutions and if added too rapidly, excessive effervescence takes place. This gas should not come in contact with the skin or eyes and should not be Inhaled. 11 Minimum Velocity of Air In (FPM) Required In Pipe 3,600 ft. 4.000 ft. 6.000 ft. 6,000 ft. Minimum Center Pip (VP) In Inches W.O. 0.97 in. 1.21 In. 1.86 In. 2.70 in. All teats for air velocity shall be made with all branch pipes of the exhaust ayatoni fulXy oponod ot tfao saiso tlmo# NOTE: See American Foundrymen1s Association Code of Recommended Oood Practices for Testing and Measuring Air Flow In Exhaust Systems. Section X: Abrasive Blasting Processes (A)-OENERAL DESCRIPTION OF PROCESSES; The abrasive blasting of metal parts embraces varied types of equipment, pur poses, and methods of projecting the abrasives, as well as kinds of abrasive material employed. The personal element is extremely involved, particularly in those types of operations where the operator must be within, or adjacent to the compartment when in operation. The abrasive blasting process is used for the removal of rust, scale, paint, sand and other surface cleaning operations, also core knockouts, and to produce certain characteristic finishes. (B)-DUST EXPOSURES INVOLVED: The abrasive blasting process cleans the product rapidly and therefore may pro duce large quantities of dust. The amount of dust is dependent upon the condition of the surfaces of the product, the' amount of abrasives used per unit of time, the method of abrasive propulsion, and the kind of abrasive material used. Additional dust may be generated in the pneumatic and mechanical handling of the abrasives and in cleaning the abrasives for re-use and disposal of refuse. Due to the dust created in such operations, all types of equipment and auxiliary appurtenances shall be substantially built and so constructed that there is no outward leakage of dust to the general atmosphere when in operation and the exhaust equipment is operating. When leakage outwardly occurs, the operators are not only affected but all other occupants in the immediate vicinity of the equipment are exposed. When the type of equipment is such that the operator must be within the blasting chamber in the direct presence of the dust created, the operator shall be protected by wearing suitable fresh, uncontaminated air-supplied respiratory equipment. (C) -GENERAL CONSTRUCTION SPECIFICATIONS: 1. GENERAL: There are several different types of abrasive blasting equipment and many adaptations of the various types to meet specific abrasive blasting problems. Many of the fundamentals of exhaust requirements are more or less common for the various types as well as the uniformity of requirements for auxiliary appurten ances. 2. AIR INTAKE OPENINOS: Openings shall be provided in all units of the abrasive blasting equipment 35 and its appurtenances for the admission of ventilating air, so that there will be a definite flow of air of sufficient volume through the parts of tae equipment to the exhaust system to continuously remove the dust created. Such openings pro vided shall be so located as to afford a uniform distribution of air flow through the parts to be exhausted and the openings within range of the abrasives used shall be so baffled or protected that abrasives will not ricochet through the openInga to the outside of the equipment to cause a accident hazard or dust emitted to cause a health hazard. 3. ENTRANCE, PRODUCT AND INSPECTION OPENINGS: All entrance, product and inspection openings, manholes and doer.-.ays into the blasting chamber of the abrasive blasting equipment or to the pits, hoppers, con veyor housings and other enclosures in the auxiliary appurtenances snail be com pletely closed and sealed when the equipment la in operation and the door or opening Jointa ahall be so designed or provided with gaaketa ao that dust and abrasives will not escape into the general atmosphere. Suitable fasteners or locking devices shall be provided to keep the doors or oovers in a closed and tight position when the equipment ia in operation. All door openings or turntable openings into abraaive cleaning rooms shall be close fitting and door Joints properly baffled or sealed to prevent duat leak age or the escape of abrasives into the general atmosphere, particularly when there la chance of the abrasive stream being directed at auoh openings. One method of sealing the Jointa tight to prevent duat leakage outward and the eaoape of abraalvea is shown on Fig. 4, which consists of a rubber tube held in place In the Joint which la inflated when the doors or turntables are in closed position. Mechanical or electrical interlocks are provided ao that the blasting operation cannot be started until the doors and turntables are in closed position and the tubes inflated. 4. FOUNDATION JOINTS: Any sections of the abrasive cleaning equipment or ita auxiliary appurten ances that are fastened directly to the floor or foundation and in which section there is dust produced, shall be sealed to the floor or foundation to prevent out ward leakage of dust or abrasives into the general atmosphere. 5. PITS AND HOPPERS: When pita and hoppers are required below the abraaive oleanlng equipment, such pita or hoppers are not an Integral part of and sealed to the abrasive blast ing equipment, they ahall be tightly oovered around the outside edges of the equip ment, except for such air intake openings provided for the admission of air for ventilating purposes to prevent the escape of duat into the general atmosphere, and such pita or hoppera ahall be exhausted into the exhaust equipment provided for the abraaive bleating equipment. 6. GENERAL CONSTRUCTION: All abraaive blasting equipment and auxiliary appurtenanoea ahall be sub stantially conatruoted. All jointa and connections ahall be made duat-tight. All exposed parts subjected to exceaalve abrasion ahall be protected by lining with replaceable abraaive resisting rubber covered duok or other suitable material to further resist the erosion and prevent deterioration of the equipment that would otherwise permit duat leakage to the general atmosphere. 36 r tf~" f'r-. 7~:: ' FLOHT ELEVATION OF A6U.ASIVE &LA6TING LOOM OB. COMPAB.TMINT 4MWINa APPLICATION OP TUOt CiALA TO OOOA. OPOWINOO coamu fiaia c.j. Tf CANTO* OHIO* C.I. CINTIH FliLSR OtOLIO SECTION 5-5 i> f TUB! IMflATIO _ -AOUWOIO COOMtOS IN UAL POSITION iR; JTAMPARI " PIPA S*T*Uf NiNMO Ltftl HUASI ICALI BI r*o* NOT*: tMTtttLOCVIMO mTIM MAY & CITMtO ILICTOICAL Ol PNEUMATIC. patented PNLUMATIC 5LAL5 FOB. SEALING DOOB. AND TUB.NTAbLL OPEN1NG5 FIGURE 4. 37 (D)-EXHAUSTDO ABRASIVE BLASTINO EQUIPMENT: XU abrasive ..blasting equipment end auxiliary appurtenanoea creating or conveying duit and dirt shall be connected to exhaust ayatema that ahall be operated during any time the equipment ia in operation to remove the dust and prevent lta escape into the general atmosphere from the equipment. (B)-EQUIPMENT EXHAUST REQUIREMENTS: 1. OENERAL: All parts sections of abraaive blasting equipment and the auxiliary appur tenances producing dust or handling abrasives ahall be exhausted and the volume of air exhausted and the flow of air into air Intake openings shall not be less than the following minimum requirements. 2. AIR INTAXE OPENINQS : Air intake openings provided for the purpose of admitting air into the equip ment or appurtenances to remove the dust therin to the exhaust system shall be of sufficient area to admit the required volume of air and the average entrance velocity of the air into such openings shall be sufficient to prevent outward leakage of dust and shall not be less than 300 F.F.M. unless otherwise specified. 3. ABRASIVE AIR WASHING UNITS Whenever an abrasive blasting equipment is `provided with an abrasive air washing unit to wash and remove the dust and refuse from the abrasives by air before re-using, it shall return the abrasives that are suitable for blasting. 4. PNEUMATIC CONVEYORS FOR ABRASIVES Whenever pneumatic conveyors are used for conveying the used abrasive^, dust and refuse to the abrasive washing unit, the air transport velocity shall not be less than 6500 F.F.M. and the air volume shall not be less than 100 cu.ft. per pound of abrasives and refuse handled. 5. MECHANICAL CONVEYORS FOR ABRASIVES The casings enclosing mechanical conveyors for handling abrasives, dust and refuse shall be operated under negative pressure and shall have an air flow sufficient to prevent the leakage of dust to the general atmosphere. 6. DISCHARGE OPENINGS Whenever there are chute or conveyor discharge openings discharging into the general atmosphere, the average velocity of air entering into the equipment at such opening shall not be less than 300 F.P.M. 7. SPECIFIC REQUIREMENTS FOR VARIOUS TYPES OF EQUIPMENT la) ABRASIVE BLASTING ROOMS Abrasive blasting rooms In which the operator is working within the room shall be provided with down-draft ventilation of not less than an average of 80 F.P.M. velocity over the entire projected floor area of the room and the air shall be exhausted from the room downward through the floor or on at least two sides of the room at the floor line, except that in special Instances cross ventilation may be used providing the average velocity shall not be less than 80 F.P.M. over the vertical cross section of the room. (b) ABRASIVE BUSTING TUNNELS Abrasive blasting tunnels are equipment in which the product to be cleaned passes Into the cleaning room or chamber through an entrance opening by some means of conveyance and passes out of the room through an exit open ing. Such equipment may be equipped for automatic blasting or operators may 38 be within the tunnel to perform the blasting operation. Entrance and exit openings shall be provided with vestibules of sufficient length or number of turns so that the baffling over the cross-sectional area of the vestibule openings provided for the prevention of the ricocheting of abrasives will be effective. The baffling In each vestibule may consist of at least two sets of doors or three sets of flexible curtains made of abrasive resisting material. The spacing of the doors or curtains shall be such that at least one set of either remains In closed position when the product is passing through the vestibule, unless the product Is so large that the blasting oper ation may be stopped during the time the product la being transferred into or out of the tunnel and In which event tightly sealed doors may be used at the entrance and exit openings. An average air velocity of at least 300 F.F.M. shall be drawn Into the vestibules through the net open area of the doors or curtains. The abrasive blasting portion of the tunnel, excluding the vestibules only, wherein operators are stationed for performing the rbraslve blasting operations, shall be provided with downdraft ventilation of not less than an average of 80 F.F.M. velocity over the entire projected floor area of the blasting portion and the air shall be exhausted from the chamber downward through the floor or on at least two sides of the chamber at the floor line, except that In special Instances cross-ventilation may be used providing the . average air velocity shall not be less than 80 F.P.M. over the vertical cross-section of the chamber, except In cases where large bulky product Is regularly passed through the tunnel, such as rolling stock, the amount of ventilating air may be reduced by providing for not less than 100 F.F.M. average air velocity over the net effective horizontal or cross-sectional area. Vhen abrasive blasting tunnels are operated automatically, or the blast ing Is directed by operators stationed outside of the tunnel, the same air velocity shall be used, but the air may be exhausted from the blasting por tion of the tunnel at any plaoe suitable for the Installation. <c) ROTARY ABRASIVE BLASTIN0 TABIBS : Rotary abrasive blasting tables are equipment In which product Is loaded on to a horizontal rotating table and passes into an enclosed chamber for abrasive cleaning. The exposed portion of the loading and unloading zone of the table shall be as small as possible so as to obtain as great a distance as possible between the entrance and exit openings In the chamber the abrasive projecting units. %ie entrance and exit openings shall be made as small as possible and shall be completely curtained with at least three seta of abrasion resisting rubber covered duck or other suitable material, spaced not less 4" apart. Additional curtains shall be looated within the chamber adjacent to the blasting units to minimize the escape of abrasives toward the entrance and exit openings. The volume of air exhausted from the chamber shall not be less than the equivalent of 200 C.F.M. per aq. ft. of gross area of the inlet and outlet openings without the protective curtains In place. 39 (d) ABRASIVE BLASTISO MILLS: Abraslva blaating whether of the barrel or oonveyor type, ahall be wentlleted at least equivalent to twenty air changes per minute, based on the Mq)ty oubloal contents of the work chamber. <e) ABRASIVE uTianm HAND CABINETS: Abrasive blasting eablneta are small enclosures In which the parts are olesaed either by the manipulation of the prodnet or abrasive stream by the operator from the outside who views the operation through a glass window. Wherever possible, prodnet openings or openings through vhlch the hands are extended, hniiid be eloeed dust-tight during operations, but In no event shall the average velocity of air entering all openings in the cabinet be leaa than 500 F.P.M. The amount of air exhausted from the cabinet shall be equivalent to at least twenty times the volume of the cubical oontents of the cabinet per minute. (f) HYDRAULIC BLASTING OR CLEANING UNITS Hydraulic blasting or cleaning units employing water as a means for cleaning with or without abrasives shall be confined within enclosures that will effectively prevent water and/or abraalvea from splashing or ricocheting outside the enclosure. Suoh enclosures need not be totally tight unless there Is evidence of dust escaping from the oleanlng operation that would con taminate the general atmosphere of the work plaoe or room. When there Is contamination of the general atmosphere because of suoh blasting operations, exhaust ventilation shall be applied to the enclosure that will exhaust the cubical contents of the enclosure not less than ten times per minute. The tendency to generate dust In hydraulic blasting or cleaning opera tions Is increased on types of units employing large volumes of water at low water pressures In the neighborhood of 100 lb. Installations requiring more than one operator within an enclosure shall employ baffling in the form of curtains or partitions that shall prevent the operators from being struok from the other blasting Jets. 8. LOSS OF ABRASIVES In order that usable abrasives may not be carried Into the main exhaust system to the dust collection equipment and thereby be lost, the outlets from the blasting cdepartment shall be of sufficient area to prevent usable abrasives from being en trained in the exhausted sir and such outlet openings should not have a velocity greater than 500 F.P.H. unless suitable abraelve traps are provided to return the abrasives and the neoeaaary allowances for resistance to air flow caused by the trap shall be Included in the resistance losses In the exhauat system. 9. ALLOWANCES FOR COMPRESSED AIR When compressed air Is used for the propulsion of the abrasives, the amount of compressed air discharged within the mill, room or cabinet shall be determined and added to the required amount of air for exhausting the abraelve cleaning equipment and auxiliary appurtenances. The amount of compressed air discharged Increases as the blasting nozzles wear and 50 per cent shall be added to the.discharged capacities of the total normal areas of all blasting nozzle areas when new. The amount of compressed air 40 discharged for a given area and total nozzle area nay be determined fron the following table. AIR DISCHARGE WITH ABRASIVES FOR VARIOUS BLASTING-NOZZLE SIZES AKD PRESSURES Nozzle Dla.Inches 3/16 1 ^4 5/l6 3/8 7/l 6 l/2 9/16 5/8 ll/l 6 3/4 Area of Nozzle Sq.In. .02761 .04909 .07670 .1104 .1503 .1963 .2485 .3068 .3712 .4418 50 lb. 27.9 49.5 77.1 111 151 197 250 309 373 444 CFM FREE AIR DISCHARGED 60 lb. 31.9 57 89.3 129 175 228 289 357 432 514 70 lb. 36.5 64.6 101 145 198 258 327 405 489 582 80 lb. 40.4 72.3 113 162 221 289 366 452 547 650 90 lb. 44.7 80 124 179 243 320 402 499 600 717 100 lb. 49.2 88 137 197 268 350 443 547 661 786 (F)-DESION OF EXHAUST SYSTEMS: All abrasive blasting equipment and their auxiliary appurtenances shall be con nected to exhaust systems and the minimum air velocity in any branch pipe or header pipe shall not be less than 3600 F.P.M. Such exhaust systems shall be designed in accordance with the rules and engin eering data prescribed in the American Foundrymen'a Association Recommended Oood Practice Code and Handbook on the Fundamentals of Design, Construction, Operation and Maintenance of Exhaust Systems. The resistance of abrasive cleaning equipment to the flow of air varies great- ly with the various types of equipment and the vendors of equipment shall be consulted arf to the resistance loss to be expected and such Information shall be given in terms of velocity pressure corresponding to the velocity in the connecting branch pipe exhaust ing the equipment. (0)-TESTINO EXHAUST SYSTEMS: A pitot tube shall be used to measure the velocity pressure of the air flow in the branch pipes and headers of the exhaust system and such measurements shall be taken in the center of a straight portion of a pipe that is not less than ten pipe diameters downstream from an elbow or bend or as near this location as the pipe Installation will permit and the velocity pressure as indicated by a manometer gauge shall not be less than 0.97 in. ff.Q. for 3600 feet minimum velocity. ROTE: See American Foundrymen's Code of Recommended Oood Practices for Testing and Measuring Air Flow in Exhaust Systems. (H)-COLLECTION OF DUST AND DIRT: All exhaust systems shall be provided with dust collection equipment to remove the dust or dirt from the exhausted air from the abrasive blasting equipment aid their auxiliary appurtenances and all such air shall be discharged out of doors except that ex haust systems connected to hydraulic blasting and cleaning units will not require dust collection equipment and such air exhausted -shall be discharged out of doors. (1)-RESPIRATORY PROTECTION: All operators who must work in the direct presence and in oontaot with the dust and dirt created by the abrasive or hydraulic blasting and cleaning operations shall be provided with, and shall wear, fresh air supplied airline helmets or masks. The airline supplying fresh air to the helmets or masks shall not be less than l/2 in. inside diameter. The helmets or masks shall be provided with a supply of fresh, filtered air awl 41 If such air la cold due to climatic conditions, the air shall he heated to at least 65 F. before entering the helmet or mask. Compressed air shall not be used as a fresh air supply for any helmet, or mask unless an adequate air filter is provided to remove all dust and carbon monoxide. The amount of air to be supplied to any helmet or mask shall not be less than 14 cu. ft. of air per minute so that there will always be a sufficient volume of air present to thoroughly purge the helmet or mask equipment and prevent dust and dirt from entering the helmet or mask openings. No valves for controlling the air supply to the helmets or masks shall be per mitted in order to prevent operators from reducing the required volume of air. In all other respects, helmets and masks shall meet the minimum requirements for airline helmets and masks as specified by the U. S. Bureau of Hines. (J)-BQDY PROTECTION: All operators who must work in the direct presenoe of the abrasive blasting or cleaning operations or water shall wear suitable protective clothing. In abrasive blasting operations all portions of the body shall be protected from abrasives. In hydraulic blasting or cleaning operations water-proof and ventilated clothing shall be worn to protect the operator from becoming wet. (K)-DUSTINO AND REMOVINO ABRASIVES FROM PRODUCT: Wherever it is necessary to remove loose dust or abrasives from cavities in a product that has been blasted and such removal is accomplished with an air blast, "such dusting operation shall be performed within the abrasive blasting equipment with the exhaust system operating and shall not be done outside in the general atmosphere so that the dust will contaminate the general atmosphere. If it is necessary to perform the dusting operation outside of the abrasive blasting equipment, such dusting operations shall be performed in a special cabinet or booth that is properly ventilated to prevent contaminating the general atmosphere. (L) -SUPERVISION AND MAINTENANCE: 1. SUPERVISION Due to the hazards from dust exposure with the use of abrasive blasting equljv ment and Its auxiliary appurtenances, the operators of such equipment shall be thoroughly Instructed in their duties so that the equipment shall be used in the manner intended and shall be operated in accordance with the instruction given by the manufacturer. 2. MAINTENANCE: The very nature of abrasive blasting operations is destructive to equipment and auxiliary appurtenances and a careful inspection shall be made periodically to make sure that the equipment Is functioning properly and that It is in good state of repair. Defects shall be corrected in order to protect the operator or those In the Immediate vicinity and to prevent dust and dirt from getting into the general atmosphere. Close inspection and supervision shall be maintained over the use and care of all respiratory equipment to make sure that it is in perfect working and sani tary condition at all times. Respiratory equipment shall not be interchanged between operators. Means shall be provided for s -rilizing respiratory equipment. 42 ADEQUATE DUST CONTROL KEEPS FOUNDRY CLEAN Allen D. Brandt industrial Hygiene Engineer Bethlehem Steel Co. Bethlehem, Penn. Di Ri.vc the past decadf. or two much thought, lime and money have been expended on "cleaning up the foundry.'' This has been done not only by plant operating and engineering personnel but also by dust control equipment manufacturers, consulting engi neers and institutions, and industrial hygiene per sonnel in insurance companies and official agencies, such as City, State and Federal Health and Labor Departments. As a result of these combined efforts the foundry industry a> a whole has come a long way, and the foumhs no longer can be considered as a dark, dirty, dusts, dangerous place of employment. There are ex ceptions. of course, and the job of cleaning up is far from complete, but the industry and the American Foundi\men's Society deserve credit for the tremen dous strides made in improving working conditions. before discussing the subject of this paper, let us recall some of the more important reasons which piumptcd clust elimination, since if we have clearly in mind the reasons why a job should be done we knou better how to proceed than if we are groping in the dark Piobably the most compelling reason was :he incidence of silicosis among foundn workers. Theic is hide agicement among the rates reported by different insesiigators (references 1. 2, 3, -f. 5. 6. 7, 8). making the schitmn of a good average value out of the question. The Iruk of agreement may be attributed to the different i\pcs of foumbies studied, number and tvpc ol luimdiv woikcis included in the group, anil prodilute lullowid b' the in'esiigaiors. Veiv high in<iih net s ,ne tepoiled b\ some investigators, but their 'indies coined selected employees rathet than all i mplovccs m one or mote loumbies. The findings fiom all studies which covered all foundn workers and different foundiies indicate silicosis to be present in less than 10 pet cent of the workers. For 80 foun dries m New folk State, for example, the incidence was 2.7 per cent: an additional 4.5 per cent showing hbiosisA These data show that while the silicosis rate in the foundry industry as a whole was not high enough to be alarming, it was high enough to justify immediate and concerted action. The second compelling reason was the high rate of Jabot turnover and the difficulty, especially in times This paper u.n presented at the Alt-Canadian Foundry Con ference. Montreal. Quebec, Canada. Sept. SO-Oct. 1. 1948. of prosperity, of keeping men on the job. This relation ship existed to a certain extent between the foundn industry as a whole and other industry generally; more so from one foundry to another: and most of all from certain types of jobs to others in a foundry. Instances are known, for example, where the foun dries found it necessary to clean up in order to oper ate at all; thev could not hire men fast enough nor keep them long enough to maintain an effective work ing force. To these reasons must be added the desire of most management to improve the working condi tions in the plants under their jurisdiction. Without the cooperation and backing of foundry management, much of the effort of those actively engaged* in this work would be wasted. The subject of dust control is much too big to be covered in one paper. There are large and small foun dries; iron, steel, brass, magnesium and other similar tyjjcs of foundries; there arc jobbing foundries and production or assembly line foundries; there are mech anized foundries and others that are operated almost entirely by hand; and many other classifications which indicate unique differences requiring special control equipment, if not. indeed, wholly different approaches to the (Iust control problem. This discussion, there fore, will be confined to those operations common to a number of foundries regardless of type. The meth ods. equipment, or principles outlined are applicable to the control of the dust at the multitude of opera tions or dust sources not common to many foundries. Foundry processes may be divided into the follow ing fnc groups which afford a convenient pattern to follow in discussing the dust problems and their control: 1. Preparation of molds and cores. 2. Melting and pouring of the metal. 3. Breaking out castings from the molds and re moving core sand. 4. Cleaning the castings. 5. Reconditioning the molding sand. Preparing Molds and Cores Little dust is dispersed in making molds by hand from damp sand. Even if sandslingers are used for throwing the molding sand into the flasks, not much dust is dispersed if the sand is moist. Most of the dust found in hand-molding areas is chargeable to poor housekeeping which allows the accumulation of dry Reprinted from December, 1948 AMERICAN FOUNDRYMAN dcteimined that the median nmtenti atiot: of tin median sallies for all 12 loumhic' is 1 >.P mppet This figure docs not compute too uutasoiubls wuh the 10.3 mppcf given cailiet lot the molding anas Core knockouts mas produce esen gin.iter sana lions in iltisi ness than shakeouts. lh caking out soli coie sand bs hand with a bat and hsdiuuhr blasting, of course, disperse sers little dust, whili pneumatic chipping oil large, inegulails shaped castings dis peises enormous amounts. Ottb six measuicmeim of dust concentrations at ion knockout opeiations wcie Fi;. 2--Ptn tiall\-enclosing hoods have hern filled to the tilting fiininccs shown at the left of photograph. will sullicc for furnaces which would otherwise mptitc two to ten times ns much air flow' to accomplish ;t s.msfactori job of control. Proper exhaust rates can not be iceommcmlcd for melting furnaces because they ;ik governed so complete]v by the fit of the hood, the M/e and type of the furnace, and the nature of the materials melted. Two miscellaneous operations associated with melt ing anil pouring produce dust exposures that merit mention. These are abrasive cutting wheels for shap ing or sizing refractors btick to be used in foundry furnaces. o\ens and ladies, and ladle cleaning, repair ing and telining. Dust at the abrasive saw should be i mm oiled as described fot similar saw s used for cut ting cores. Dm: ptoduced in connection with ladle mainten ance can be cnnnollcd b\ exhausting air fiom the ladies thinugh a llextblc hose, which terminates inside and neai the bottom, whenever the woikman is inside the ladle. The amount of an that should be exhausted d: pi nils upon the size ol die ladle, but should be about '-Mu'1 din pit sipi.iu looi of opening at the top ol tin I a 11 i i I! wmk of diis natuie i' mfiripicnt and of 'liuii dmaliun. thi man doing it can be pioieiled In i.i nine a miih.mii.il filtei respiiator of a is pc a pi n oi i d In i In liu i r.i n ut M mes. Shakeout and Core Knockout Xli.ikmg out Castings and lemming cmi sand aic iinpiniaii; soinces of diisi dispel moii. 1 hi amount of cliisi dispiised will \aii 11 eniendoiisli. depending upon a miiiibei oi factois. \mong thesi ate. (Ii m!: pi I a l U Ic ol ilu casting. (2) ilnnessol the mold ing sand. ; i - tatio ol metal to sand: fli shakeout and con sand iemm.il methods emplosed, and (5> i ale taken in handling castings, dusts Masks and bot tom llll.lt l Is From Table 1 it mas be seen that of the 33 dust icincmti.niou me.isuiements made at shakeout opera tions in the New 5 m k State sill ies , 13. or 39 pet cent, wetc found to be less than 13 mppcf; four, or 12 per lent, side found to be between 15 and 30 mppcf: and the lemaining In, or -19 per cent, exceeded 30 mppcl Fiom the data shossn in the teport it mas be Fig. 5--Positive dust control is effected at a sjmkcout by means ol an exhaust-ventilated enclosing hood. made in the New York State studs. From Table 1 it mas be seen that two ol these concentrations, or 33 per cent, were below 15 mppcf: three, or 30 per cent, sieie between 15 and .30 mppcf: and the icmaming one. w hich constituted 17 per cent of the total, ex ceeded 30 mppcf. Shakeout and cote knockout opeiations in particu lar should be segregated from less dusts opeiations such as molding, coremaking, pouting and melting in oilier that the dust created bs them be ptevcnicd horn making those other opeiations hu/uidoits to health, liven il the shakeout is updated on an ollshift, much unsuspected dust mas be added inudvcrtenlls in the adjacent molding ana dining the sunking shill bs jailing loose some ol the dust that had aii tunulaicd on the tafleis and olliei suil.ues ol the molding area dining the shakeout pet toil Dust coniml measuies lot shakeout operations differ wuh the shakeout procedure, depending upon whcihct the work is done by hand oi mechanical means, and whether oi not il is done at centtal ot loiali/eil loca tions. In the jobbing, anil possibls esen the semipioduction foundrv. the molds aie sioml use) a large Moot area until tlicv are poured in a group. Shakeout under these ciicumsi.litres does not per mit the application of local exhaust setitilation. Dust control can be accomplished bs (I) allowing the cast ings to cool as much as possible before shakeout: (2) wetting down the floor and molds befoic shakeout and the mold sand immediately afterward: and (3) handling castings, bottom boards and flasks carefully. In addition, if this work is done (luting an ofl-shift, fewer men will be exposed to the dust dispersed. !  C.ood eilKT.ii ventilation is necessarv in ihc shake out aica, not mil' u> keep the ihisi at a minimum btu .ilbo 10 dilute tile initanng gases and smoke to an unobjectionable level. Large roof fans which arc operated onl\ dining the shakeout pet tod arc of great help m lilts respect. Even if the lotegoing measures an taken, it is sometimes necessary lor the men en gaged in shakeout o|>crations to weai appropiinic lespiiniors. In contrast to general or sea tiered shakeout opera tions. dust contiol in the mechanized or production foimdrs can be accomplished very effectively as a rule In local exhaust ventilation. A thorough discussion hI ventilating shakeout operations would lccpiirc more tune and space than is permissible here. Therefore, the subject will be covered oniy briefly; reference should be made to other articles for details1". The cenii.il shakeout table is in common use in mech anized loutidi tes. Whether the molds reach the shake out table In conveyor, crane, or other means is not impoitant except as it allects hood design. To keep the required exhaust rate at a m mi mum and still accomplish good control, the shakeout table should be enclosed as completely as possible. Typical installations arc shovvii in Figs. a, 4 and 5. The com mon tvpes ol hoods in use are termed overhead hoods and side hoods. Downdraft and complete enclosures have been attempted without much success. Down draft fails latgelv because the air llow is least when it is needed most because the sand and the casting cover some of the grille just as the mold breaks, and complete cncloMiics are tret|nciitlv impract.cable be cause of changes in mold and casting si/es anil shapes. Although the dust Irom huge shakeout tables can be i aptuied diet lively bv the use ol simple side hoods, suit shields attached to the hoods retime suhstaniiallv the tci|uirctl ventilation iatc foi adequate dust con nol. The time and cflort sjH iit l>\ tin hood di signet and tile fonndrv operating heads on deviiopme an operating ptocedme that "ill permit tlit ii'C of 'id-, shields will he repaid man' times over in Imm opei.n ing cost and improved dust contiol. I he usual e\ hnusi tales for hoods at shakeout tables i.tnge It out L'(H) to 4(H) cfm per siptate foot of shakeout guilt, di pending oil how ucarlv the hood encloses the table. As with shakeout operations, removing cote sand presents dust control problems which van tteinendouslv ftoni fonndrv to tumuliv. Tin pmbiems ns well as the control measures ate not unlike those associated with the shakeout. II the iemov.il ol cote sand is mu difficult anti is accomplished hv hand, such as the use of tin iron bar or knocking the castings togethei. dust control can be cHecied bv doing tins work in a centra! exhaust ventilated booth similar to a spr.iv-pnmt booth. An exhaust rate of about 130 cfm per sipiate loot of booth opening will be adequate. For cores which are difficult to remove, pneumatic chipping, blowing with compressed air. or blasting with water or a mixture of water and sand is required. These operations (with the exception of lmlraulic blasting) should be done in an exhaust ventilated chamber or room similar to sandblasting rooms. Ait at the rale of about SO elm pet squaic foot of hori zontal cross-scciional area should be moved through the loom, which should be kept under a smnlj nega tive pressure at all times to prevent the escape of dust. These conditions merely prevent the escape of dust from the chamber or room: they do not protect the worker in the room. Such workers require suppliedair respirators or helmets lot adequate protection. Cleaning castings by chipping, blasting, grinding, tumbling, blushing, and burning produces much dust. Most of these operations, however, lend themselves \civ well to dust connol bv local exhaust ventilation. In fact, dust control in the cleaning room of most foundiics is much more common and effective than in oilier departments of the foundn. Consequenth. dust concentrations at casting cleaning operations in the run of-mme foundry are usually low, notwith standing the fact that these operations are potent sources of dust production and dispersion. This is evidenced, for example, by the results repoitcd in Table 1. Of the Mi dust concentrations determined in ten different foundries, 17, or 65 per cent, were less than 15 mppcf; eight, or 31 per cent, ueie between 15 and 30 mppcf; and only one, or 4 per cent, was .those 30 mppcf. Further analysis of the data given in the report ol the New York State study shows the median dust concentration of the median \alucs for all plants to be 13.3 mppcf. This is lower than the similar sallies gisen earlier for the shakeout and molding operations. Details on hood or enclosure design and on re quired exhaust rates for stationary grinding wheels, tumbling barrels, and blast cleaning equipment such as rotating tables, cabinets and rooms have been pre sented several times elsewhere11-1-, and svill not be icpcatcd heic. Dust from portable grinders and blushes should be controlled by downdraft or sidedraft. pieforabls in booths or partial enclosures, as shown m Figs, li and 7. The required ventilation rates ran with the nature of the hood but, in general, ik Mich as to pioducc a capture vclocitv of not less than 350 1pm in the grinding area. (.ood eemial ventilation is adequate if onh a few pot table gimileis are used and if the castings arc free / 'e- -- gmuhnz booths provide dust , 'Oil in1. 1 in hnnil IS till I n/cgl(l/ p/ll/ of the Collector. from sand. Swing-frame grimlcis should b. pmvided with booth-tvpc hoods which pain.db inclose the frames of the grinding equipment 1 he mpnied rate of air flow depends on several ciicumstanccs. but foi an arrangement such as shown m Fig S an inward air flow of 150 to 300 fpm into the hood opening directlv behind the growling wheel pioduccs good ventilation results. Probable the most difficult problem of dust con trol in certain foundries is that associated with pneu matic chipping of sand which adheres to the castings, cspcciallv large and irregularis shaped steel castings. Local exhaust bv means of movable hoods has not proven practicable. Hydraulic blasting with sand and water is being used with some success foi such clean ing jobs (Fig. U) . Even shot blasting can teplacc some of the pneumatic chipping being done. While these procedures do not eliminate the dust problem per se, they must of necessity be done in chambers or rooms which prevent escape of the tlust. The workers who operate the blasting equipment must be protected by suitable respiratory protective devices if stationed inside the cleaning room. Burning off excess metal from castings seldom is done to such an extent as to introduce a dust, smoke or gas control problem except for the burner. Gooil general ventilation' will solve this problem as a rule, but if it is a continuous operation it should be done in an exhaust hood similar to a sprav booth which is ventilated at a rate of about 100 rfm pc* square foot of opening into the booth. Careless handling of castings while charging the tumblers or while grinding will produce considerable unnecessary dtisi. A word is in older regarding gen eral ventilation in the casting cleaning room. Since most of the operations arc usually provided with local exhausi ventilation and the exhausted ait is not rc- C oVcVd.ucd. ilu 1i!ii;i'c'it'ah adequate i.o( ;k (good Validation in cleaning operations. Di'ii ibuiion uf lilt make-up :m may not he sans- Luii'i' 1io\m\u. ami if the make-up an is drawn iiuni adjoining foundry dcpai tmcnts. die mi cnici- iii" die cleaning room iimv be contaminated cxcc>- M\eh befoie u enters. This condition can be atoided In enclosing [lie cleaning loom and drawing die air Iioiii some loom or shop ulicit- there is little atmos pheric contamination, or by supplying outside air, which must be tempered in cold weather. Sand Conditioning Dust produced be sand conditioning in foundries sane' from almost none in the small foundry, where die used sand is moistened and cut over by hand, to l.uec amounts in those foundries where sand condi tioning is almost wholly mechanized and the used sand must be handled considerably before its mois ture content can be increased. Even with mechanized handling little dust is produced if the sand is damp. Sand conditioning equipment that must be considered m the dust control program includes screens, con\c\ors, mnllcrs, riddles, elevators, magnetic separators. Fig. S-.-t battery of exhaust-ventilated booths contiols the dust produced in su-uig-fiame grinding opt unions. Fig. 9--Hydraulic blasting method of denning huge castings ol adheung sand prevents escape of much dust. I ig. 7-- liuulh-type exhaust enclosures for controlling, the that nvated bx bclt-sandtng of propdlor blades.1 1 lie amount of dust produced by sand conditioning equipment is influenced largely by whether the sand is handled drv or moist, and whether or not control meastiies arc in use. From Table 1 it will be seen that the concentrations found in the New York studv "ere quite high. Of the 12 measurements made, three concent]ations, or 25 per cent, were found to be less than 15 mppcf; five, or 42 per cent, were between 15 and 30 mppcf; and the other four concentrations, or 33 per cent, exceeded 30 mppcf. The data in the re port shotv that the median concentratiton of the me- dinn values for the seven plants in which sand con ditioning operations wcic investigated was 27.2 mppcf. The comparable concentrations loi die molding aiea, shakeout and cleaning loom weie mils 10.5, IS O and 13.3, respectively. Dust control ai sand conditioning is a lel.nivcly simple and straightfoi ward procedure. Electric rid dles, except when used only infrcquentlv, should be housed in booths similar to spray-paint booths which are ventilated at about 100 cfm per stpiarc foot of opening into the booth. If other unit or portable conditioning equipment is used, the sand should be moistened properly before it is processed, and in some instances respirators are needed In the men who operate this equipment. Mullers, screens, transfer points at belt conveyors, elevators and magnetic separators should be hooded or enclosed and ventilated at rates summarized in Table 2. Figure 10 shows a diagram of a complete sand conditioning system with hoods as required. The foregoing related almost entirely to specific conditions and control measures. There are a few import.tm Imul.imcntal considerations which apply .ilmobi cquallv io all foundries. These are (1) buildin" construction and plant layout, (2) general ven tilation, and f.'i) housekeeping. building construction, especially the la\out oi ati.mgemcm of departments and equipment, is of pri nt.u\ concent m tlust control. Gencrallv. little can Im_ accomplished in this direction in existing loundi it s. New foundries, on the other hand, should be mi laid out that there is a smooth or natural flow of niatet ials. Mechanization is important not onlv luraiisc it nit teases efficients in production, but because it also makes possible more specific and positive dust temm.il In one case an existing small brass fotindrv u.is teat tanged and mechanized at what management fil: uas te:i ilie cost. New cases of lead poisoning did not occm, ssheteas the\ had not been uncommon belote the thangemer. In addition, and to the pleas ant suipusc ol management, production pel man moie than doubled and the percentage ol ie|ects (hopped almost one hall. \\ alls should be smooth and painted in light colois. l'io|irnons exjiosed beams etc., should be kept to a minimum so that then an lenel plans foi dust to (ollei: and hum 'ninth n must In Kiinoid ion limb its; r In j.iiied loose, f.ood 111 mm i i.u i oi i aids J'mili 2 -- Minimi m NYxiii.uiox Rills ink vi bvxu Coxunioxixc. Em irvii \i lloons 1 11 u i i tint, n 1 F.Miami Rcipnmmiu 1 i.invfir Points. . . . 3*i(i <fni pci foul of belt width hut not less (ii.in ).'0 fpm mdi.ift. bucket Llc\aiois . . I.n li.uixi from elcvaiot head !(>u (fm per s<| ft of rasing rioss section Viml Screens . . . ... 1 1 at (Ink --'U cfm pet sq ft of srieen area l>ut not less titan 290 fpni nuhaft Cs limlncal-- IU0 cfm per s<j ft of snecu nose section. Volume mas he doubled to pro\idc reipmcd fines removal Sand Mullers......... .130 fpm liirougli openings m dust hood Sand Hms ........... . 130 fpm indraft Imt not less than 0 5 cfm per cu ft of Inn cnpaniN. in speeding production and in Iiuiih In nmc The size of the foundis in relation to its niodurtmn rate has a profound influence on die dustiness bu.insc the atmospheric (Inst concentiations decie.i'i >' the crowding decreases. Good general \emilation is impottant because all lotmdries have manv minor and scattered dust soun.es Even if the main tlust sources ate conn oiled dice us cb In means of local exhaust and other specific measures, good general ventilation is needed to prevent the general dust level from rising to undesirable levels. A rule of thumb method for deciding upon mini mum general ventilation teqtmccl is 20 an changes per hour for mechanized foundries, and 12 air changes per hour for plants that are not mechanized. When applying this rule, it must be icmembcred that the general ventilation required varies considciablv from plant to plant. In some instances these suggested rates will be inadequate, espccialh if the other and more specific control measures are lacking I cl ore the dust measurements had been made, all foundries studied were classified into thiee groups as regards the housekeeping in evidence. For the purpose of this classification housekeeping oitiv was considered. The approximate average dust (oiucmrations for the molding areas, the shakeout opeiations, and the cleaning departments (the three departments for which dust concentrations are reported in each housekeeping class) were 7 mppcf for the good house keeping group: 25 mppcf for the average group: and .`12 mppei for the group classified as poor. Acknowledgments The autluu wishes to acknowledge the courtcsv of Amei ican Air Filter Co.. Inc.. Louisv ille. L . Y Rubber C.o., New York, artel Pangborn Corp., Hagerstown, Md.. in furnishing the photographs used in the paper. References 1. M . Lanitaii. Tulmonan Disease Among Cleancis of Catlings Due io Dust," Arch. f. Grnethjtath. . Gear?lnh\g.. 112. 1032. Uj'ir liuti //vg. 20. 1933. 2 W. Landau. "Silicosis Among Catling Cleaners." Airh f. Gcu ci befxith. u. CtJii -rbrh\g.. V. *ilj, 1933. Ahsn Hull. H\g. S. 727. 1933. '' 3 W. J McConnell and J. U\ Vcbncl. "Healih Ha/.mis in llie 1 ouiidn. lndmiiN,*' }. hut. Mvg. Jo. 227. 1934. 4. F M. W aiheld. Results of \-i.in ( licsi L\nmm.mons \inong 2.M*0 Workers in a He.iw Indieurv Plant," hid. Med., V. 392, 193a. \i>'*11- j. hui. //\g.. ioi. i93j j. | 1'. Kells and R. C. Hall, "Silicosis in Modem Tmindi ics." Vc ;r )mh Stmc J. of Med., '7. 1. 1937. o L. H Osmond, "Dim Ha/aul Among Fottiulrxmen." .Jm. / Unrut . }S. 122. 1937. 7 () A. Sander, I lie Lung Findings in Foimdrv Workers. \ Four Vcai Siirvcv." Paper read before 1 ml. H\g. Section \ 1*. H. A. at fifith Annual Mccimg. New ^nk. On. 7, 1937. 6 "Silicosis m the Foundry Indu&trv," New \<uk State DcpA. cf Labor. Sftectal Bulletin Xu. 1^7. Slate Oflice building. AlhaiiN, 193R, 9 1 Hatch. C F. Williams and 11 0. Holm. Hum Concen trations in Foundries,*' The Industrial Bulletin, JS, 89. (Feb.) 1939. Issued br Nc\ York State Laboi Dep t., Alham, \. V. 10 |. M. Kane. "FoundiA Ventilation," The Foundry, Feb. and Mar.. 1910. It. "Silicosis PrcNcmion--Dim Control in Foundries." Limed States Dep t, of Labor. Div. of Labor Stnndauls, 1910 (for sale b\ SupA. of Documents, Washington, D. C.). 12. Allen D. llramlt. "Industrial Health Lugmccung." John Wilc\ and Sons. Inc., Non York. 1947. TRANSACTIONS of the American Foundrymen's Society Proceedings of the International Foundry Congress Atlantic City, N. J. May 1 - 7,1952 VOLUME 60 Published by the American Foundrymen's Society Chicago, Illinois 1952 \ l THE FOUNDRYMAN LOOKS AT AIR POLLUTION By N. H. Keyser* and H. P. Munger* ABSTRACT The air-borne contaminants from a foundry are classified as dust, fumes, and noxious gases. They originate at many points in the foundry. Particle size u the mast important property of solid contaminants. Each foundry finds itself in a different situation because the nature of the operation differs from foundry to foundly and because location of the foundry is of great importance. The foundryman and the local air-pollution control authorities should cooperate in working out an individ ual program for collecting dusts and fumes, employing the knowledge and research methods at hand. The technical methods for controlling air pollution are fairly well developed. These include dry inertial collectors, and wet scrubbers which have a wide range of efficiencies and also a wide range of costs. Filtering methods and electrostatic pre cipitators an among the most efficient dust collectors. Several newer methods are going through the production development stages. In spue ol a number of factors which partially offset the cost of air-pollution control, cleaning air rarely yields a net profit. The actual cost will depend largely on the amount of cleaning required by the local conditions. The public will eventually pay this cost. The Problem The (oundtvnian has a definite interest and a re sponsibility in preventing excessive discharge of waste into the atmosphere. But how much waste can be discharged into the air before we say the discharge is excessive or that the air is "polluted'''' A few de cades ago, dense clouds of smoke coming from the stacks of our industrial plants were regarded as a sign of prosperity, and nothing short of a dense cloud ol noxious lumes would have been described as air pollution. On the other hand, refreshing cotmtn air contains wind-borne dust, pollen, and gasses from decaying vegetation. The present trend is to define some concentration of contaminants between these two extremes as ex cessive. Air is regarded as polluted when the concen tration ol contaminants exceeds that which is in jurious to propelty, to health, or to human comfort. For the most part, thetelore, air pollution is of great est concern in large centers ol industrial activity. Overloading ol the air with dirt ma\ result from 'Batielle Memorial Institute, Columbus. Ohio. St-103 numerous small sources of contaminants over a large area, or a single concentrated source, or any combina tion of these two conditions. Smoke and fly ash from industrial stacks, railroad locomotives, or the chim neys of homes and schools are the most obvious sources of contaminants. Burning trash and leaves in metropolitan areas, gob piles in coal-mining areas, and the exhaust from Diesel locomotives and trucks or even passenger automobiles also contribute their share of contaminants. It can be seen that the found ry, in most cases, is just one of the many sources of air pollution in a community. ( Aside from the contribution of the" foundry to the over-all burden of contaminants in an industrial area, the foundry, as an individual industrial plant, has a problem of community relations. When the neigh bors see nothing but smoke pouring from the foun dry, they get the impression that the foundry is a smoky, dirty place. They are inclined to blame their dirty washing on the smoke that they can see, even though the actual source of the dirt may be some dis tance away or perhaps just the general condition of that particular area. One of the problems facing the foundry is that of attracting young men to work in that industry. Cer tainly a reputation for smoke and dirt does not help the foundry solve this problem. Each Foundry is an Individual Control Problem To those who have studied air-pollution problems, it is evident that each plant presents an individual problem. The methods for reducing contaminants must be tailored to fit this individual situation. The municipal and county programs, in each case, form the backbone of air-pollution control. Each com pany within a local air-pollution control district should work out its own program in cooperation with the local air-pollution control engineer. Any program of air-pollution control should make the widest use of the knowledge that is available. The first information required in setting up an individual program for the control of air pollution is a knowledge of the physical and chemical nature of the contaminants emitted into the air, especially 364 il. i V. ' w their particle-size distribution. The concentration of the contaminants and the points at which they leave the plant also need to be known. Other important factors are the natural surroundings of the plant and locations of population centers and farms. Of equal importance are the atmospheric conditions under which the contaminants are found objectionable. In the dispersion of air-borne contaminants, the nature of the country and the atmospheric condi tions play major roles. Flat country, especially near the Great Lakes where strong winds are frequent, favors the rapid dispersal of dust, fumes, and nox ious gases. Narrow, deep valleys furnish pockets in which contaminants may collect to form relatively high concentrations. Temperature inversions which form over pockets in the land stabilize the air and prevent the normal vertical dispersion of contamin ants. A temperature inversion is a condition in which the air at ground level is colder than the air above it. Los Angeles county is an outstanding example of the influence of the nature of the land surface and atmospheric conditions on the buildup of contami nants over an industrial area. In Los Angeles counts, a large concentration of industry is situated in a basin surrounded on three sides by mountains. Tem perature inversions, in effect, put a lid on this basin. Because they cannot get out of the basin, smoke and fumes and noxious gases frequently build up for several days. Fogs, rolling in from the ocean, com bine with the concentration of man-made contami nants to create a powerful eye-irritating smog. It is be cause of this set of conditions, which are abnormal for most of the rest of the country, that the air-pollution standards for Los Angeles must be so rigid. Devices for Analyzing Air-Borne Contaminants There are well-established technical methods for determining what are the air-pollution problems of any individual industrial plant. These methods util ize devices for collecting and analysing, the air-borne contaminants. Analysis of an individual foundry's contribution to air pollution can be made right at the source. For example, the amount and nature of emissions from a cupola can be determined. Measure ments of dirt falling on the surrounding community also can be made. A new device, developed at Battelle, not only determines the amount of dirt fall but also establishes the direction from which dirt is com ing.1 A knowledge of the direction from which the dirt is coming is of special interest in determining whether the contaminants are of local origin or have been blown in from another area or community. Devices for measuring the influence of the surface of the land and the atmospheric conditions on the dispersion of contaminants are also in use. For stud ies just above ground level, instruments have been attached to fixed structures. A new technique uses a kite balloon to carry weather instruments and air sampling devices up to altitudes of 500 ft or higher.l-s-3 in highly industrialized areas, these methods provide the tools for securing a three-dimensional picture of contamination of the air. The 'Nature of Air-Borne Contaminants An effective program fot controlling air pollution from the ioundrv must be based on a knowledge of the origin and nature of the contaminants that are emitted into the air. It is customarv to divide the contaminants into four principal classes: (1) smoke, (2) dusts, (3) tumea, and (4) noxious gases. Smoke is defined as the solid or liquid particles resulting from incomplete combustion of organic materials. Soot is an example. Dusts are solid particles of anv nature which have been produced bv mechanical pro cesses and released into the air. Particles of iron and abrasive lrom the grinding of castings are typical dusts found in the foundry. Fumes are solid or liquid particles in the air, commonly generated by sublima tion, vaporization, or chemical reactions. The white fumes liberated during the baking of cores, and the brownish fumes which arise from hot iron or steel are typical examples of fumes in the foundry. Sul phur dioxide and carbon monoxide are typical nox ious gases with which the foundryman is familiar. Probably the most important property of contam inants is their particle size.4 Particle size coupled with density and shape determines the distance contami nants will travel in air before they settle to the ground. Visibility of contaminants is determined by the number and size of the particles in the air and by the degree to which moisture condenses on the par ticles to form fog. Finally, the particle size of the con taminants determines what methods of sampling and analysis can be used for studying the air and'what type of equipment can be used for separating the con taminants from air, and for their subsequent disposal. In view of the importance of particle size in airpollution control, the foundryman should have an idea of the size of particles involved. The size of smoke, dust, and fume particles is commonly expressed in terms of the average diameter of the particles mea sured in microns. A micron is 1/1000 of a millimeter, or 1/25,400 of an inch. The size of particles in the air may range from over 1000 microns for raindrops to considerably less than 0.01 micron for sulphur di oxide and other gases. Several other examples which are useful in visualizing the size of the particles are: (I) a 50-mesh sand has an average diameter of 295 microns, (2) a 325-mesh silt has a diameter of 44 microns. (3) the smallest particle visible to the naked eye is 10 microns in diameter, and (4) the particles in tobacco smoke have an average of about 0.3 mic ron. Particles below 1 micron in diameter tend to stay suspended in quiet out-door air almost indefinitely, whereas those larger than 1 micron tend to settle at a more or less rapid rate. In agitated air, such as found in foundries and other industrial plants, par ticles 10 microns or larger in diameter may stay sus pended in the air for a considerable length of time. The range of particle size for a number of indus trial dusts and fumes is shown by means of bars in Fig. 1. Foundry dusts include such coarse particles as the cinders and other debris blown out the stack of a cupola and the finer dusts from the foundry  ' " jf 366 ' The Foundryman Looks at Air Pollution INDUSTRIAL aerosols GROUND LIME!STONE HjS04 COSICENTRATOR MIST S03 MIST PIGMENTS ROSIN 5M0KE CARSON BLACK 1 1 1 I : PULVEIRIZED COAL --------- I ..................... STOKER FLY ASH PULVERIZED COAL FLY ASH OIL SMOKE 1 i DIAMETERS OF .6AS MOLECULES. FOUNDRY DUSTS ---------------------------------1 CEMENT DUST ALKALI FUMES ZINC OXIDE FUME ... METALLURGICAL DUSTS ! MAGNESl UM OXIDE SMOKE ! metallurgical1 fumes gas cleaning equipment settling chambei * gAs washers ---------------------------------- !----------------------------------!----------------------CENTRIFUGAL dust separators SPECIAL GAS WASHERS BAG-HOUSE FILTERS________________ 1 SONIC A<5QljDMERATQR TYLER SCREEN ' 1___________ ELECTROSTATIC PRECIPITAT1 QSS MESH 35 " too 200 225 ___1___ - ^ 1; 1 ! --J__ 111 -1-111I 1000 100 10 1.0 01 PARTICLE SIZE-MICRONS J___ L. 0.01 Fig. 1 --Particle Site of Industrial Aerosols and Equipment lor Cleaning Cases 0.001 shake-outs and cleaning room. Metallurgical fumes comprise such contaminants as the brownish fumes coming off the electric or open hearth, and that part of the cupola and the non-ferrous-melting furnace emissions resulting from volatilization and oxidation of the metallic constituents of the charge. It is apparent that the foundryman must con tend with the entire range of particle sizes considered to be air contaminants. For the sake of economy in controlling the air contaminants, the foundryman should use the type of collection equipment that will do each job at the lowest cosl The particle-size ranges for which broad classes of collecting equipment arc effective are shown in the lower half of Fig. 1. Additional details on collect ing equipment are given in a later section. Source of Contaminants Air-bome contaminants come from many points in the foundry. In many cases, the melting department is a major source. In fact, the melting department has been the first to attract the attention of air-pol lution control authorities in many cities. The electric furnace and open hearth for steel and iron melting emit clouds of reddish-brown fumes, especially during melt-down when the charge is not protected by the metal is at its maximum temperature. The advent of the oxygen boil in steelmaking has aggravated the fume problem. The open-top cupola belches forth a stream of hot gases clouded with solid particles. The coarsest par ticles are the size of coarse sand. The finest particles must be viewed with an electron microscope to distin guish them. Coarse particles settle on the foundry roofs, yards, and on the foundry's immediate neigh bors. The finer particles drift away to settle at some distance from the foundry. Sulphur dioxide, formed from sulphur in the coke, and unburned fumes from oily scrap add their characteristic unpleasant odors. A typical sample of the cupola stack-gas emissions will contain on the order of 35 per cent of its par ticles in the zero to 5-micron range and about 50 per cent of the particles will be over 44 microns (325 mesh). The remaining 15 per cent will be spread out over the range of 5 to 44 microns. The concentration of particles above 44 microns (325 mesh) is chiefly dust and debris consisting of broken coke, fine metal chips, rust, sand, and dirt, which are picked up by the rising gas stream and carried out the suck. The particles in the 0 to 5-micron range are chiefly fumes from the volatilization and oxidation of iron, silicon, manganese, and certain tramp elements by the in- largely responsible for the opacity , or color-of the suck, gases, primarily because there are so many par ticles in a given weight of fume as compared to a given weight of the coarse particles. It ukes 1000 particles, 1 micron in diameter, to weigh as much as one particle 10 microns in diameter. The core room also is a major contributor of fumes in the atmosphere in and around a foundry. Fumes given off from core oil and cereal binders during the baking of cores are pungent and irritating. A host of obnoxious compounds have been identified in the fumes given off by linseed oil dur ing drying. These include acrolein, formic acid, ac etic acid, acrylic acid, butyric acid, carbon monoxide, and a number of other volatile products.* Presum ably, many of these same compounds are generated during the baking of cores and also during casting and shake-out of molds containing cores. No entirely satisfactory substitute for core oil has been developed which does not give off fumes and odors. In some cases, the odors of the substitutes were more obnoxious to many foundrymen than the odors from core oil. The shake-out and cleaning room are also sources of large quantities of fumes, dusts, and noxious gases. In the shake-out, large quantities of hot sand are suddenly exposed to air. Particularly where many cores are used, large quantities of fumes and noxious gases are generated by the incomplete combustion of organic materials in the mold. Added to this burden are fine sand and binder materials thrown in the air by mechanical agitation used to shake the molding material off the casting. In the cleaning room, the problem is mostly one of dust generated by such op erations as chipping, blasting, and grinding, although metal and other fumes do arise from welding opera tions. Miscellaneous sources of air contamination in the foundry are open fires, handling of dry sand before it is tempered, parting agents, metal fumes from the ladle during transfer and pouring, and mold gases. The foundry pattern shop also has its dust-control problem. In this case, however, the materials involved are woodworking shavings, chips, sawdust, and, if metal patterns are used, there is the possibility of metal and abrasive dust. Methods for Control The industrial hygienists have developed excellent methods for reducing the concentration of contami nants in the air within the foundry. They have ap proached the problem from several angles, among which are (1) to prevent or to reduce the production of dust, fumes, or noxious gases, (2) to reduce the use of materials which give rise to dust, fumes, and noxious gases, (3) to provide personal safety equip ment to prevent inhalation of dust, fumes, or noxious gases, and (4) to extract the dust and fumes from the various points in the plant where the contaminants are generated. The extracted dust- and fume-laden air may be exhausted directly into the atmosphere outside the . foundry. If the burden of dust and fumes of this air is great, the air must be passed through an air cleaner to avoid air-pollution problems. The foundryman is then faced with making a decision as to what type of dust collector to use. Control of air pollution starts with the dust hood and ducts to convey the dirt-laden air to the collec tors. Much good engineering has gone into dust hoods and ducts. Since the principles are well known, the subject will not be discussed here except to men tion one of the problems encountered in the foun dries that have applied dust control to existing plants. In most instances, space is at a premium, and dustcontrol equipment must be built into extremely lim ited space. This leads to a temptation to use hoods, piping, and collectors of inadequate size. Available Types ol Dust Collectors The technical methods for cleaning dirty air and gases discharged into the atmosphere are fairly well developed. The proper selection and application of cleaning equipment depends on a knowledge of the types of collectors available and their performance. Dry inertial collection methods are the most econom ical but have definite limitations. These methods de pend on gravity or the momentum of a particle to carry it out of the gas stream. In its simplest form, the dry collector is merely a settling chamber or an enlargement in the duct carrying the dust-laden gas. Practical limitations on the size of such chambers do , not permit designs with low enough gas velocities to extract fine particles. The minimum particle size normally collectible in a settling chamber is on the order of 40 to 80 microns, depending on the design. The cyclone collector is a widely used collector of the inertia] type. By introducing the dust-laden gas tangentially into a circular chamber, a centrifugal motion is created which throws the dust particles to the side where they deposit, or drop to the cleanout in the bottom. Decreasing the diameter of the cyclone makes the gas travel in a tighter circle and increases the centri fugal force for throwing the dust out of suspension. The small-diameter cyclones, therefore, are more ef ficient where particles in the smaller size range are encountered. On the other hand, because of rebound of coarse particles, the collector may not be as effi cient for removing particles of large size. Multiple units of small-diameter cyclones are required to handle a large volume of gas. A large variety of makes and configurations of cy clone collectors is commercially available. In gen eral, however, the collecting efficiency drops off rap idly for particles below about 20 microns in diam eter for the large-diameter cyclone and below 10 mi crons in diameter for the small-diameter multiple cyclones. In addition, the collecting efficiency is prac tically nil for particles below 5 microns for simple cyclones and 2 microns for multiple cyclones. This, of course, limits the type of dust that may be col lected. Efficiencies in the neighborhood of 97 per cent have been reported on coarse material, such as saw dust from planing mills.* In contrast, they may 368 collect only between 10 and 25 per cent of the solid material in stack gases from a boiler.7 In many cases, where it is necessary to install addi tional exhaust fans, or where space is limited, a mech anical centrifugal collector will be found practical. This type of collector uses a high-speed impeller to provide the centrifugal force for throwing the dust out of suspension. The impeller also acts as a fan for drawing the dust-laden gas through the cleaner. At the point of greatest concentration of dust, part of the air is skimmed off and carried to a settling chamber. After depositing the entrained dust, the air is recirculated in the system. Louver and dry skimmer collectors also depend on inertia for throwing the dust out of suspension. Inertia concentrates the particles of dust in the small end of a slotted metal cone. About 90 per cent of the air passes through these slots to the blower and stack, while the concentrated suspension passes into a small cyclone. The exhaust from the cyclone is recycled in the concentrator. Centrifugal Separators and Louver Collectors Both mechanical centrifugal separators and louver collectors have application for collecting particles in the size range collected by cyclone separators. Dry inertial collectors, as a class, are not suitable for collecting fine dust (particularly particles below 10 microns in diameter). They are satisfactory, how ever, as rough cleaning devices for reducing the load on high-efficiency final collectors with which they are frequently used. On the other hand, as final clean ers for coarse, non-toxic materials, such as wood or metal chips, they do an excellent job and are simple and inexpensive. These collectors can be built to handle relatively hot gases which makes them eminenilv suited for such applications in cupolas where merely the removal of the coarses particles from the stack gas is sufficient to satisfy local conditions. When dry inertial collectors are inadequate, it is advisable frequently to go to one of the wet collect ing methods. Wet collecting methods depend on a simple process of washing or scrubbing die dirt out of the gas and wetting the particles to increase their effective diameter so they may be removed bv simple lollectors. such as a cvclone. In addition to removing dust, wet collectors also can remove sulphur gases which may sometimes be important. Static Spray Washers The simplest form of wet cleaner i> the static sprav washer which may be seen mounted on the top of mans cupolas. This equipment can remove 50 to 75 per cent of the solid matter and a portion of the SOin the cupola effluents. However, a Jarge portion of very fine solid particles escape. Wet scrubbers are more efficient in removing the smaller size particles than are the simple spray wash ers. Wet scrubbers depend on mechanical means of admixing a spray of water with the dust-laden gas. Thev emplov the cyclone, rotarx centrifutril collector . ... ' ...i .............. ...............................................i. The Foundryman Looxs at Air Pollution Roughh speaking, the efficiency of these scrubbers is related to the work applied to admixing the water and gas. Scrubbers can be very efficient and give very clean gas. Because of the high power require ments for the highly efficient scrubbers, it is customarv where verv clean gas is required, to use a scrub ber of moderate efficiency, followed bv other types of final cleaners which require less power. The we cleaner reduces the load and, at the same time, coo; the gas. Cloth filters or bag houses are becoming a more familiar sight around the foundry. They operate on the same principle as the vacuum cleaner in the home. They have been applied to cleaning the ex haust from the shake-out and cleaning rooms. In similar applications, they have been found to oper ate with dust-collecting efficiencies of over 99 per cent. It has been only recently, with the develop ment of the glass-cloth bag which will withstand temperatures up to about 500 F, that bag houses have been utilized for the difficult job of cleaning the hot gases from the. cupola. They have been found to satisfy the difficult requirements of the Los Angeles County Air Pollution Control District.* All material passing through the cloth filter is below 5 microns. Efficiencies are good on particles down go a fraction of a micron. Bag houses are limited, however, to applications where there are no condensable fumes or gummy materials presenL Electrostatic Precipitators Electrostatic precipitators are probably the most efficient of all collectors. Collecting efficiencies are very high on particles down to a fraction of a micron. Although electrostatic methods do not remove gases, there seems to be no lower limit to the size of solid particles that they will remove. Electrostatic precipitators employ up to 75,000 volts to induce a negative electrostatic charge on the sur face of the dust particles. The dust particles are then repelled to the positive electrode, which is con structed to serve as a dust catcher. Among the newer methods for collecting dust and smoke are the sonic agglomerators.-10 Sound waves cause the small particles of dust to vibrate, thereby increasing the number of collisions between particles. Upon collision, surface forces on the particles of cer tain types of materials cause them to adhere to one another. Through a series of collisions and adhe sions. small particles agglomerate to such size that they can be removed from the gas with a cyclone separator. The method is limited to very small par ticles, as are found in smoke, and it does not work on all materials. Further developmental work is required before its possibilities in the foundry are known. One of the latest improvements in wet collecting equipment is the Venturi scrubber.11 In this scrub ber, water is broken up into a very fine mist. The mist and gas pass through the venturi portion of the collector where the very small droplets wet and ab sorb the very small particles of dust. A cyclone sep arator then collects the wetted particles and drops N. H. kEYSER AND H. P. MUNCER Control.of Combustible fumes: v. ; Combustible fumes can be destroyed by oxidation or combustion. Where the ratio of combustible ma terial to air is high enough, as in the cupola stack gases, combustion will be self-sustaintng_once it has been started. An ignitor is sometimes used for ignit ing the gases during periods when they do noc ignite freely. Lean mixtures, which will not maintain com bustion, must be heated to temperatures on the order of 1200 to MOO F, to complete the oxidation. In some instances, fumes from the baiting of cores have been reduced by recirculating the air in the oven through the burners. One of the newer methods for oxidizing combus tible fumes is the catalytic combustion process. Very dilute mixtures of combustible vapor or gas will oxi dize at temperatures as low as 350 F, or less, in the presence of a catalyst. This principle has been ap plied commercially to the oxidation of a number of fumes and gases, including the fumes from the bak ing of cores. Of special interest is the fact that the heat obtained from the oxidation of these fumes is returned to the oven to reduce the amount of out side fuel required to keep the oven hot. The Cost The purchase cost of dust-collecting equipment ranges from something less than $100 per 1000 cu ft per min treated for simple cyclone separators, to SI000 or even more for certain of the very high effi ciency collectors, such as bag houses, electrostatic, or disintegrator-type washers.15-13 Power consumption may be as low as 0.1 kw per 1,000 cu ft per min for simple gravity settling chambers, to as high as 10 kws per 1,000 cu ft per min for high-efficiency scrubbers. These figures are for total power, including electrical energy, water-pumping power, power for necessary auxiliary equipment, and pressure drop through the apparatus. One thing that must not be overlooked in estimat ing the cost of dust-control equipment is the actual volume of gas handled. The more gas handled, of course, the larger the size of collecting equipment required. In the design of dust hoods, for example, sufficient excess air must be drawn through the equip ment to flush all the dust-laden air from the source. The equipment must clean all this air plus any excess that is taken in. Cupola stack gases are another ex ample where the volume of gases emitted is greater than may seem at first. The volume of gases gener ated by a cupola may be 2 to 4 times the volume of air blown into the tuyeres. Burning of the gases in the stack and aspiration of air in the charging door may increase this volume to 5 to 7 times that of the tuvere air. Cooling of these gases before thev are passed through the dust collectors, of course, re duces considerably the volume of gas that must be handled. Nevertheless, the volume that must be handled is more than the volume of air blown into the tuyeres. Who pays the cost of clean air? The answer to this is simple and one which everybody should know. Jhe. cost of dean air is eventually paid by the publie. The degree that atf' polluuon is controlled in the future will depend largely upon the amount the pub lic is willing to pay for controls in terms of increase of cost of products. The materials recovered in the air-cleaning opera tion seldom have much value. There have been fig ures published on the large savings in nonferrous smelting operation by collection of the dust from the Hue gases. For example, it has been estimated that S27.000.000 worth of metals have been recovered in the copper industry alone.u Unfortunately, in the foundry industry, in general, the products recovered in the dust collectors are not nearly so valuable. For the most part, they may be classified merely as dirt which has to be hauled off to the dump. Fly ash collected from the cupolas may have some value as a filler for concrete. However, it probably must sell for considerably less than concrete itself. It must be used close to the source and must be avail able in quantities large enough to be worth handling. Recently it has been found that fly ash makes a cap able pipe eliminator of the non-exothermic or insul ating type to apply to the surface of feeders on cast ings.15 This would permit the foundry to consume its own fly ash to some advantage. For the most part, the small quantities of salvagable material involved make the cost of handling more than the products might be worth. It seems hardly worthwhile to develop a useful market for them. Other opportunities to realize some return on the investment in dust collectors are difficult to evaluate in dollars and cents until the equipment is installed. The factors which may partially offset the cost of clean air are: (1) reduced maintenance, for example, less frequent cleaning of the roof, (2) better working conditions and workers' morale, and (3) better rela tions with the neighbors. The last two factors should help attract better workers into the foundry and re duce labor turnover. The by products and other benefits derived from gas cleaning rarely yield a net profit on the entire cost of the gas cleaning operation, but thev may help materially to reduce the expense. Bibliography 1. H. P. Munger, "The Engineering Approach to Air Pollu tion." presented at The American Public Health Association, San Francisco, California. November 2. 1951. 2. H. P. Munger, "Present Status of Air-Pollution Research," Mechanical Engineering, vol. 73, no. 5, pp. 405-411, May, 1951. 3. H. P. Munger, "Meterological Methods for Studying Air Pollution." presented at the XII International CongTess of Pure and Applied Chemistry, New York. September 10-13, 1951. 4. H. P. Munger, "The Spectrum of Particle Size and Its Re lation to Air Pollution," presented at The First U.S. Technical Conference on Air Pollution, Washington. D.C., May 3, 1950. 5. W. M. Lord. "Foundry Cores and Moulds: Vapours and Fumes Evolved From Organic Bonding Materials," Iron and Sled fLondon), vol. 23, January, 1950, pp. 21-25. 6. R. Dennis, C. A. Johnson. M. \V. First, and L. Silverman, "How Dust Collectors Perform," Chemical Engineering, vol. 59. no. 2. pp. 196-197. February. 1952. 7. A. J. Grindie. "Dust, Fume and Smoke Supression." presented to Iron and Steel Engineers, Cleveland. Ohio. September 370 26. 1950. and reprint by Whiting Corporation. g. P. Siechcrt and H. B. Menardi. "Glass Bags Clean Cali fornia's Air." The Iron Age, vol. 169, no. 4. pp. 78-80. January 24. 1952. 9. H. W. St. Clair. M. J. Sendlove. and E. V. Potter, "Agglo meration of Smoke. Fog. or Dust Particles by Sonic Waves." Industrial and Engineering Chemistry, vol. 41. pp. 24)4-2438 (1949). U.S. Bureau of Mines. R. I. 4214. 10. H. W. Danser and E. P. Neuman, "Industrial Sonic Ag glomeration and Collection Systems." Industrial and Engineer ing Chemistry, vol. 41, pp. 2439-2442 (1949). 11. H. F. Johnstone and M. H. Roberts, "Deposition of Aerosal Particles From Moving Gas Streams." Industrial and En gineering Chemistry, vol. 41, pp. 2417-242) (1949). 12. C E. Lapple. "Processes Use Many Collector Types." Chemical Engineering, vol. 58. no. 5. May, 1951, pp. 144-151 . 1). O. T. Zimmerman and I. Lavine, "Chemical Engineering Costs." Chapter 12, Dust Collecting Equipment, p. 209, Pub lished by Industrial Research Service, Dover, N. H. (1950). 14. H. V. Welch. "Fume and Dust Problems in Industry," Transactions, A1ME, vol. 185, p. 9)4 (1949). 15. "New Foundry Techniques; Part 2," Canadian Metals, vol. 15, no. 2, February, 1952,' p. 27. The Foundsyman Looks at Are Pollution DISCUSSION Chairman: F. W. Shiplev. Caterpillar Tractor Co.. Peoria. Ill Co-Chairman; J. R- Allan, Internationa! Harvester Co., Chicago. Recorder; H. F. Scoatr, American Foundnmans Society. Chicago. Orville Laabs1; Which type of dust and fume collector is preferable, the dry or the wet type? Mb. Keyser: Foundry men should use whichever type dust and fume collector is necessary to meet local air pollution ordinances Use the dry type if possible because of its lower maintenance costs. K. M. Morse*: What data can you give us on the size spec trura of cupola emissions. Mr. Keyser? Mb. Keyser; About 50 per cent of the particulate matter emitted is dust larger than 44 microns. Approximately S5 per cent is metal oxides 5 microns and smaller. Very little matter between 5 and 44 microns is emitted. SDircclor of Personnel. Uoiverssl Foundry Co.. Oshkosh, Wa rindmmol Hygienist, U. S. Steel Co., Pittsburgh. < M* _ . . Imtrtirnm fttHmdrymnm _-------,,I*> Svpti'tnhvr 19i2 j Volume 22 Number 3 Official Publication of the American Foundrtnnen's Society 33 Toward higher productivity 4 V 4 Qfl . > e, iik t rge nt ^ lely* *,!. t robthe M Wit *, I 1 Setting an externa) core for a 50.000lb 4-M3ge centrifugal blower cast ing at Chiiinbcrsburg Engineering Co Chambersburg. Pa The finished mold--entirely cement-bonded sand --consists of a bed. a semi-cyhndrical core with n separate nozzle core .ii each end. and four external cores. Aheady in place is one of the nozzle cores i dark colored i. At the start. bed of cement sand is levelled in . frame containing core prints. The st-Mn-c> Jmdncal core is rammed in puce tn a box assembled on the bed Cores are aligned using gage lines on the bed and a level. All compound surfaces arc carefully gaged during assi-moly to insure specified wall thicKnesses. Publications Committee H. M. Si. John. Chairman C Co.. ChicafO C. H. Long Ijlifitf Memorial Institute W 0 McMillon tnjtionji Harrrstei Co . Cntcafo H J Rowe iiun'iRu* Co o< America. PiMifevifti F J. Wolli international Nickrf Co Crtfrl A.F.S. Headquarters OiC S. Michujnu Chicago 5 Wm W. Moloney Xccrcinry-Treasurer S C Motion, Trrhinrol L>>rrcinr American Foundryman H. F Stobie, Editor Powl Fountain, Eriilor terry Koeller, AdvcrtiSimi Mnnnycr Helen Owdek. Advertisiwj Proilwrfion LoVerne lohn, Crroilrrlioti Advertising representatives Cenlrol 6 E E. Cleary. Conrnirrcinf 4 Sormaj Bank Bldg . Berea Ohio Berea 1-7719 Midwe.tern H__Thorpe Covngion Co . i'1 h. Miehman Aee . Chicago Superior 7-SOU loUern T.oben B Weston 550 Fifth i re . .Vote York, ,V V PUtea 7-C1U 34 The job record card, a valuable tool for the jobbing foundry ft. W. Griswold 37 Small foundry, small castings 44 The non-ferrous cleaning room Martin G. Dietl 59 Causes of hot tears in steel 65 Design-production teamwork in the steel foundrv J. O. Fell 40 Foundry crucible service life R. A. Hemdl 53 The truth about disease caused by foundry dusts 0. A. Sander 56 Are technical graduates getting adequate training in college? Hmmi flroiou 50 1953 A.F.S. Convention 55 Directors set financial policies 63 S & H & AP progress report 68 Regional conference programs 71 Z953 European foundry tours 104 News of technical committees 27 Foundrymen m the news 90 A.F.S introduces 95 Chttptt*r officers mid directors 17 Products and processes 18 Free foundry information 87 Abstracts 92 Book reviews 72 Directory of A.F.S. chapters 75 Chapter-news 97 Rnmmed up and poured 106 Foundry tradeneuis 112 Coming events 114 Advertisers' index 115 Classified advertising Published monthly by the Ameri can Koundrymens Society. Jnc., 616 S. Michigan Ave . Chicago 5 Subscription price in the U S . Can ada. and Mexico $3.00 per year; elsewhere. SC 00. Single copies 50c Entered as Second Class Matter. July 22. 1938. under Act of March 3. 1879. at the Post Office. Chicago. September 1952 ' 3 Technolog/ WT-t"rrV" Tho truth uboutdisease vausod by foundry dusts This paper--by the man credited with hoving done most to separate fact from fiction in the field of dust-caused dis eases in the foundry--was given at the Foundry Health Conference held at Ann Arbor, Mich., on April 11-12, 1952. It and all others presented at that time have been compiled into a 200-page publication, Health Protection in Found ry Practice, published by A.F.S. o. a. sandei: / Industrial Medical Consultant. Milwaukee, Wis Although others may soon replace it at the top of the list, silicosis has for almost a century been the prin cipal occupational disease caused by foundry operations. There are still far too many foundries producing this entirely preventable disease. On the other hand, more and more foundries have developed dust con trol to such a degree that it has not caused any silicosis in their employ ees for many years This is the goal toward which all of us are working. Terminology Silicosis is readily defined as a "fibrosis of the lungs resulting from the inhalation of dust containing free silica"; it offers little grounds for misunderstanding Pneumoconiosis, on the other hand, has caused more definition trouble than all the others Put together, yet genencaily it is the simplest to define. It simply means, dust irt the lungs". There is no im plication of what the dust is or sstiether or not it causes reaction. h is a shortenin': of Zenker's ong- mai term, "pncumonoconiosis" which proposed in 18311 Therefore there sttould be no implication of fibrosis m tne term, because ue now know las Zenker did not) that there are umerous dusts which are entirely n,'rt when deposited in the lungs, 'rt'en do not cause irritation or ir,,sis. and which do not predispose ''tuberculosis These have been `net] the "benign pneumoconioses'' different iate 'bi theemm from the tic pneumoconioses Beccause pneumoconiosis is a gen '''d term and covers all dusts * bother harmful or not, it should a^e no place in occupational disease `JSvs There the terminology should Oust exposure at shake-out and other dust-producing operations can be readily minimized by appropriate hoods, forced exhausts, and other devices, whether the operation is manual or powered. Establishing healthy conditions is only the first step in combatting the industrial silicosis problem as it exists today. be specific and only those pneumo conioses which may result in impair ment of lung function should be in cluded--silicosis and asbestosis. Pathological aspects Foundryman's silicosis is a modi fied silicosis. The fibrous nodules seldom are the classical whorlcd spheres resulting from pure quartz exposure The old sandblasters had those before they used positive pres sure helmets. Today's foundrymen are exposed to far less quartz (or free silica) dust than they are to iron and carbon dust. Dust in typical foundry atmospheres seldom con tains more than 20 per cent free sil ica. with iron dust running from 60 to 70 per cent and carbon dust from 10 to 20 per cent. With such atmospheres and with the total dust counts sufficiently high, a modified silicosis may result in which the fibrous nodules develop more slowly, if at all; they always are more irregular than with free silica alone, and secondary emphy sema does not occur around them. There also appears to be less suscep tibility to tuberculosis than with the classical quartz fibrosis. It is because of these modifying dusts already present in foundry at mospheres that the author does not recommend the use of aluminum dusting. Workers are already getting the maximal benefit from modifying dusts without adding another modi fier. The goal is to continually reduce the silica percentage along with total dust dissemination, not to add other dusts to the air. Functionally, silicosis becomes a disease only when it is advanced or when it is complicated with tubercu losis. With early discrete nodular fibrosis, there is no interference with the exchange of gases across the al veolar membrane, and no loss of elasticity of the lungs. Only when September 1952 53 fibrotic nodules become confluent end massive, fibresis and secondary emphysema result is there a measur able impairment of lung ventilation. Witnesses for this are the thou sands of foundry workers with min imal silicosis who daily'"'do thenheavy pinsical work without diffiultv and who show entirely normal ventilatory values with function tests. Exceptions are the occasional individuals with very little silicosis and high-grade obstructive emphy sema. These usually are the older workers who have a naturally de creasing elasticity of the lungs com bined with long-standing chronic bronchitis, bronchiolitis, or asthma, the bronchial irritation often having been caused bv excessive smoking plus chronic sinus infection. These cases cause the most med too often arc being advised by their doctors to leave their trades, The fear caused by such well-meant but ill-considered advice has caused more disability than has silicosis it self, in the opinion of the author. Think of iron first The author also believes that the time has come to think first of iron when evaluating the nodular x-ray patterns of foundry workers, even when there is no doubt about there being some silicosis present as well. The first question should be. "Hew much of this nodulation is due to iron collections?" While the answer is not always easy or possible, it makes for far less pessimism in the prognosis when one can say that a considerable part of the nodulation ducers Foundries that arc safe for any worker must change their em ployment practices and aliow almost anyone to work m them There must be less concern about potential future liability cases, and less rejection of workers with min imal lung changes The aaneer of tuberculosis developing m a silicotic lung later in life has diminished al most to the vanishing point as the opportunities for contact with active cases of tuberculosis decrease. Moreover, workers with minimal changes acquired over a period of years will not progress to a more advanced stage of silicosis if properlv placed and protected. It seems much sounder to take a chance with work ers having a minimal amount of sili cosis than to make them unemploy able and semi-invalids. icolegal difficulties because they have is probably due to iron. t I real ventilatory disability which most The industrial hygienist has the Few offending foundries doctors truly believe is entirely due very important job of making to silicosis. Statistical studies on the foundry atmosphere increasingly Even though relatively few found- ( incidence of emphysema in the gen safe for the continued employment of ries today are still producing new j eral population at various age levels the workers. Industrial physicians, cases of silicosis, a considerable will help solve some of these diffi on the other hand, have the equally number have old employees with culties. Such studies are currently important job of making these work varying degrees of silicosis who had being made. However, still more ers feel secure in their chosen trade. their significant dust exposures necessary is the constant realization Workers must be assured that many years ago. It is from this group that minimal silicosis never is dis their lung changes will not progress of older workers that most of our abling except when associated with to a dangerous stage with the im disabled advanced cases afise. tuberculosis, with a continuing pro proved dust control. New employees Unfortunately, however, from time gram to educate the medical profes with minimal and uncomplicated to time real cases develop in younger sion to these facts. silicosis or siderosilicosis must be ac workers, and these special hazards cepted without hesitation and so need special attention. Large steel Iron dust in the lungs placed that their minimal changes foundries, for example, make large will not increase materially. Where and complicated castings with diffi Another factor in foundrymen's this has been done it has been a cult cleaning problems. Cores fre silicosis which bears constant repe major factor in helping solve the quently cannot be blasted or washed tition is the iron dust which all silicosis problem. out, but must be dug out with pneu foundry workers have deposited in Industrial commissions, no matter matic hammers. These operations their lungs. That these iron collec who the personnel, cannot be ex have been the mam silicosis pro tions contribute to the x-ray pattern pected to consider minimal silicosis ducers, but have been largely solved of the silicosis is seldom considered as non-disabling as long as foundries by the development of larger and in evaluating the dcciee of develop consider such workers unemploy more forceful hydraulic blasters. ment of a case. able. The unhesitating hiring of af While the first step is to so control The amount of iron in the lungs fected workers would be a major dusty operations that silicosis cases may var\ all the way from the mini step in the light direction. There is no longer will develop in anyone, mal and probably negligible traces no reason why minimal silicotic that is not enough to solve the prob in moldcrs and corcmakcrs to the workers cannot stay on their jobs lem. Those who already have some gioss collections in welders, burners, and new workers .with minimal silicosis must be allowed to continue and grinders Some of the latter may changes cannot be hired in foundries their chosen work, not only for their have nodular x-ray patterns due to where dust control has improved to former employers but for new em the iron alone which are radiologi- such a degree that new cases of sili ployers as well. rally indistinguishable from silicosis. cosis can no longer develop. They must be reassured by indus For this non pigmentation. Zenker's trial physicians that they are not as term "siderosis" is perfectly proper, Reassurance, optimism provided there is no implication of suming undue risks by continuing their trades, which makes medical fibrosis in the term. The time has come for reassurance control of equal importance with Siderosis is as benign a form of and optimism in dealing with this engineering control. In fact, it must pneumoconiosis as could be desired. problem, and the medical profession be a joint program with mutual co It causes neither fibrosis, irritation, must be the first to recognize this. operation between the engineer and I nor progressive tuberculosis. Yet it Such optimism is only impossible in the doctor. With such a team, any is being misdiagnosed as silicosis foundries which are still producing silicosis hazard can be adequately every day. and workers so affected, silicosis cases: their first step must controlled provided the will to do with or without minimal silicosis, all be to correct the offending dust pro the job is there. 54 Americrn Foundryman Practical Aspects of Dust Suppression I'UtT I Bv V. B. LAWRl| M.Sc.. K.R.M.5.. A.l M INCIDENTAL generation of large quantities of dust is a feature of many industrial proc esses. In some, the tlust is danger ous to health: in others, although perhaps innocuous, it appears in objectionable quantities. Higher output often increases the density of the dust cloud generated, so the modern factory may aggravate the du-l problem. The term "dust supression" in cludes all methods bv which at mospheric dust concentrations are reduced. These methods fall into two main groups. One approach aims at prevention of dust genera tion. The other is directed to the control of dust cloud which have been allowed to form. The former, which mav be de scribed as iluil elimination, is alwavs the better and often the more dilficult method. The latter, referred to as r/u.s/ iniilrnl. i<- never so good, although it mav be the unlv practical ex pedient. It is. however, of great ptai heal importance to keep in mind lliC'C fundamental difTcri in - iit tei hmque. I )u-I -upres-ion ran be applied III three wav-. I' ll-t and br-l Ielinunal mu of the dii-lv pnu c~-. I be set ond i~ alteration of the prore<' giving rise to the dust, so that less dust is produced. This is not so good as complete elimina tion. but it reduces the amount of dust to be controlled, and so facil itates application of control meth ods. Finallv. the dust cloud mav be controlled after it has been al lowed to form in the atmosphere. Where no alternative is avail able. control methods will have to be applied. In the over-all design of a dust supression svslem. however, they should aluavs be considered last. Success often depends on the thoroughness with which the first two methods have been used, and the degree to which the actual for mation of the dust cloud has been restricted before the control meth ods were applied. Although local exhaust ventila tion is often ncccssarv. it is onlv one wav of controlling dust, and m certain cases mav not even rep resent the major feature of a good dti'l-suppn s-mn ..v stem. Local exhaust ventilation is not alwavs successful. It commmilv fails to achieve its end because it has been regarded as the onlv method, instead of being used in conjunction with other methods of dust suppression. One other general observation must be made. Local exhaust ven tilation is emploved to remove dust--not air. This requires some know ledge of the properties of the dust to be removed.* and also of the manner in which it might he expected to behave. It also means that the normal method of estimating the requirements of the ventilating svstem. with reference to the volume of air extracted, mav give an inadequate impres sion of the amount of dust it will rt-ninv e. / ha artnic. u h/i h uppvtifvtl uncum! I\ in liic Hnti'li luitnul of I M.t t '*.tft1\. i' prt \cnicti in anil dm <1 hi rm ilirottch lonrtcw tin A%i\nl Ni>ni\ ha flic Prri rnlmn of it>iticnl\ l.nmlnn. t llt/\ftahnn\ arc hum i iit/n ' 11 ml fiiani* in the f . V I Pan II i>i thu arm it n fm h nutrr \pct/fit all t uilh hn nl n/i//fW iitiitlnhtin. uill appear in an i ill I \ I > M/c Dull and smoke collector hocdi behind shakeouts have a capacity of 18,000 cubic feat of air per minute. (Allis-Chalmers Manufacturing Co.) U Notional Safety News, febrvory, 1952 M. ] I! "eui-ra:. I!'1' 1 ;: i .i tin- -imple-l iMCtiloil m <m-! mio pri-i,ni. 1 'ill 11 .ii".i'' H" i -l hcrau-e il provide- ,i i ..!ii|lirii and final .i it - w it i.. tit. i. t.. I >i. i *. Fm llu-vni"i c. U atom- tin mi'-- nil i for i o-l l\ i on! r. 'i .ij 'i n mu' i'- wliitli uni' oiiuju ,in i-iiiii.irr.i -- i ii" |\ Ur iv .imi>imi i f *iiji f diu! makr .inti t -nimuoii' <i<- ijkiimK on thr i l; i nirliiiL' >*ldlT ]! a ri^i'on.il'U' 'l.ti' <'! viii inn \ )- to lo lihimlnitvi1;. Dov'H-draH ventilation through grille-topped tables is effective in removing dust generated in the process of sanding and grinding castings. Thi- should not he overlooked tt lien testing an installation. 1 lie fai I tit.il n unit extracts a sufficient volume of air per minute mat not nerejrih inrlieatc that it is cxt rail in" dust satisfac lurih . Iiceenl ttork implies that theie i- -till ample snipe for cither f u in laiueiital or empirical ilcteli 'I'liiciil t. based mi obserted piuiiomriin. am! that careful .irri'dt Minnie studies mat t ield fiuilful re-ulls. and the produetion engineers of the indusln eoneerned should ap preciate each other s methods, and the difficulties and limitations in herent in these methods. Elimination of Dust The hest nay of dealing ttilh mot anted dust is to slop making Prohaiils tin- rainr.-i u.i\ nf drnlin" uith mi*: \\u- t-- \w! u. TIima\ oflrr Oil!' lllt'l III 'I I i f 1 ll|-l elimination if it proto po-ihlc t.. wet the raw matninl before prm ess work fomntciH e-. No ilu-i ttill be rui-ei! a- lout; a- tin- ma terial remain? ttet. While ttaler ttill not ttet fvnclv divided materials, thet can often lie welted if the -urfatc tension of the ttaler is lowered In the ad dition of wetting agent-, git ing what is tailed "wet water.'' A further advantage of wet water is that it penetrate- large mas*c? of material much more ipinklt . There are. however, other wavs of eliminating du-l. although the -7 o puce Tin- nvlfnul nf a|>prn;i(/)i <kni.iinl' .i 111 ui ) i 113 i I * * r rotijuralinn ill.in i' often r\nirn( irtv\r('n thr srnlddJih'j ni^iniTr* tin- ninth.init .i i i' n L' 111 it i - win. (li*-iLr n 1 he ] > I an l. iitwl tin inrn in ' harp'* of 11 r m 1 ur h.i.i If ll.f f.,,t. >r\ i- a nett one. 1 i 11 - i " ii ier ......... -I ii mill unhide I i n a n ii i In I -* i tli.it a ,-u it.il do Imililiii" itiii he erei ted. In these in mii-lani e- 11n tariou- methods if 11 ii -1 -uppri-.--nm can lie applied, iitlier -mglt or in ennj unel inn t> il Ii eai h iil her. Il i- important In realize, howe'er, that sin h a result 'till he .ilneted milt tt lien the various iiu-I innlrol method- are seen in piooer jier-peelne and usn! in suitable eoordmatnm. if teulilatme eipiipmenl i- u-eil. as it often it ill be. l lie t iiit ilal iii" engineer Well designed hoods remove dust from grinding without drawing it past the worker's breathing rone. Exhausted air is filtered before it is recirculated through the workroom (American Air Filter Co.) Notional Solvty Mews, februory, 1953 37 Oust suppression : ' ' , V < from i po-^r-iljiiilv of 51 * doing can he dclermincd onlv bv experts in the process concerned. It demands a " idc knowledge of the technical or scientific principles involved in the indu'trv. coupled with great ficxibililv of mind and the faculty of devising new. and perhaps uncon ventional working methods. A good deal of dust may result from dressing or cleaning steel castings after they have been re moved from the mou Id. This dressing is necessary because some of the moulding material adheres to the casting, and must be removed by pneumatic chisels. If it were possible to make cast ings in such a fashion that none of the moulding material adhered to the steel, this dusty cleaning process could be avoided. This opens up a wide field of investiga tion which the British Steel Founders' Association is vigor ously exploring. This particular work is regarded a; long-term policy, and in con sequence other methods of elim inating the dust arc being tried in the treatment of castings. One successful development lias re sulted from changing the method of cleaning. A flux injected oxvacetylene burner is now being used to clean the casting in place of the pneumatic chisel. This has not eliminated the cleaning proc ess. but it has ofTerpd a method of cleaning w hicli. in certain cases, mav eliminate the dust cloud. These example- indicate a wav of dealing with the dust problem which i- tar ton often ignored, and cmplin'-ize the need for a clo-c examination of all (lu^tv processes with a view to eliminating the dust. Even where there appears to he little chance of immediate suc cess. the ideal should never be forgotten, and the installation of a dust-control system should not be allowed to stifle efforts to attain a dust-free process. The second object in dust elim ination is. perhaps, less ambitious than the first. This is a change in the process to reduce the amount of dust generated. It is always important to reduce, as far as pos sible, the dust which is generated, because' the smaller the residual dust cloud can be made, the easier it becomes to control it. One example of this approach occurs in the efforts that founders are making to reduce the amount of core binder used in moulds. The atmospheric impurity pro duced by the core binder is in the form of fumes, not dust, but the principle remains the same. Once again no general suggestions can be made, because each industrial process must be treated by a spe cialist who understands all the factors involved. This discussion lias been con cerned only with the reduction of tlie total amount of dust which must be dealt with by control methods. But there may be an other very important factor. Some dusts are dangerous to health, and the total dust cloud may contain a dangerous fraction. In this case, the outstanding reason for elim inating part of tlie dust lies in the fact that the health risk can be removed if the dangerous fraction of the cloud can be eliminated. A w ell-known dangerous dust is free silica (SiOp). It is known that in many industrial processes where free silica dust is likely to lie produced, it will be accom panied bv other dusts w hicli may not be dangerous. Efforts are be ing made, therefore, to eliminate the free silica fraction of the air borne dust cloud. One example of this i* discontinuing the use of silica flour as a parting powder. Other powders arc used which may produce just as much dust, but the dust is innocuous. Control of Dust When tlie limit of practicable du=t suppression has been reached !> me molt I'l'.'iim- imUiuds ol eliminating dust at source, there will'`till remain ample scope for the application."( control methods in cases where it is impossible to prevent the formation of the duM cloud. The common method of du-i control is bv ventilation, and tinmav be eniploved .is local exhan-t ventilation or as general ventila tion. or more probable as a duplex svstem using both. It is of some practical impor tance to appreciate tli.il loeal ex haust ventilation and general ven tilation form tvvo complementary parts of on? ventilating system. They should therefore he designed together in new buildings, and when loeal exhaust ventilation must be fitted into an existing room tlie whole system should be integrated wherever possible. Local Exhaust Ventilation When the evolution of dust has been prevented as far as possible, the next logical step is to design local exhaust ventilation. This should prevent the dust cloud from spreading into the general atmos phere of the room. * Two advantages accrue when this is done. In the first place, the dust can be removed more effec tively and more cheaply if it can be contained in a small space and exhausted as a concentrated cloud. In the second place, general ven tilation can he designed on the as sumption that very small amounts of dust will be present in the general atmosphere. This implies that a relatively small volume of air will have to be handled. Capi tal costs will fall, and equallv im portant. heating costs will he re duced al-o. Dust-producing processes should always be housed in buildings designed to facilitate ventilation. More emphasis should he laid on tiie simple fact that ventilation is cheaper and better in a properly designed building. Ventilation of a dusty process often means that large volumes of air will be ex tracted from the building. This in turn means that heat loss in the 66 Nofionof Softly News, februory, 1953 7/ J_J\inq Ui'oncj an WU,, 'll^hitcy Say*: VtV Wijx' off those dim. greaw. dippen tools with ' .in mdu'iri.i! shop joss cl Kent them irom vour local member ol rite INSTITUTE OF INDUSTRIAL LAUNDERERS >627 K Strett, N. W. Washington. D. C. M tested as lhr\ .irr turni'i! in or before bring i--noil f'.T u-e If j tool ]ir.ni'r di'ffiii'1' it I' lmmrdiali'h lapsed ami turned m llu- rli-i-trn-.il depart men! fot i. |iair. Since a tool can be rmoplrlciv levied m icton 'ccmi.l- tinaildilional unit, pi.we- no huidri: mi tilt' tool Cl ill. \\ riL'limi' ir-~ than six pounds. it ni.iv nU" hr U'fil a< a portable iii'tinment I. let tool' at the )>mnl of opei.i lion. Most t in trival department:, hair arrrplrd tin- new IrMine deuce lircaur n aid? them in 'pollin': the hazard. It mean, that after a I tool crib attendant has found that 1 the equipment ground i' broken or that there is a power ground, j the tool is then tagged and sent to the elccfrieal department and gives the electrician a clue a to | what to look for rather than to J spend time tearing doim the entire equipment. | Dust Suppression j --From pnze 6f> , wear a DUPOR No. 40 the Respirator that is U.S.B. ol M. Approved lor Type A Dusts More then 40 sq. In. twin filler oreo. Sanitary foce doth. Soft rubber face mosk. Controlled breothing . . . check valves guard against re*breothing stale oir... exhalation volve exhausts breathed oir. Greater visibility ... no blind spots! Does not interfere with goggles or glasses. Scunfilt $ ZPOO cent--------------- & H. S. Cover Fog-Proof, Gai-Tight Goggln for use with obove respirator. . . . 52.00 pp H. S. COVER, South Bend, Ind. i signed ventilating _s\>tcm merelv serves to pollute the whole room, rendering conditions worse bv dissipating impurities which would otherwise have polluted onlv the air ahoie their point of origin. Flat roofs oflcr the worst condi tions for upward \culilatiou. The rising air does not romerge to the point at which I lie fan is placed, hut spreads linrimutaliv on inert ing the ceiling. The best wa\ of dealing with such a state of affairs is to insert a false roiling. The false ceiling is perforated all oier its -airfare and the rxtractiiin fails are installed in tile ceil ing ahme it. There is. therefore, an r\cn extraction rale over the i whole area of the ceiling and the , rising air will lie extracted at the point it meets the reding. The ( method is more efficient if hang ing partitions are placed over areas where large volumes ol fumes are generated. Downward Ventilation Rooms which do not contain hot processes may he i rutilated downward, from roof to floor. | This method is not so common in j Critisli industry, hut there seems 108 Notional Soltty News, February, 1933 111jm.m11u><i. .\ili*i|uaii' facilities b'r '.i'll tv i" - !'f 'm.iinlcn.iiicc and" fc|i.in rk arc .t\ailiilitc tu a group ...mi- ..f the mo~t Inglilv skilled tm i ham' - c\ci as-rmbleil in one |.a-i. I>ut ict least, in its contri bution in a grind safety record, ha- Iiccm tin- program intituled In tlic inntractur lf` have the mil kmen utilize their leisure hours .......rucli\ el\. Available for the use of all concerned arc free nnnic-. a vorv complete library, a imbbv simp, a recreation room, a niii-ie rnum. the local radio sta* 1 mu which broadcasts 2-1 hours a ila\. ami the local daily paper. Onl\ through the active com bined efforts of the top manage ment nf The Corps of Engineers, the i nntrar lor. and the insurance minpanv has it been possible, under such rigorous conditions, to .main a safetv record which is five limes as good as the average i.on-trui lion, of this type. in the ( nut mental L nited Stales. Check It - / / tun ftnut' 3 ) ami engineered, being made of In*.i\ i gauge sheet metal, fully a i * ni ndi-d. protected In a fused - irrmi. npcraled at a safe voltage .-( (< M.lt-. and contains heavy duty - .mi.n t-. telavs and good wiring in-nlc. lui'lhcr. tin- u-c of the instru ment i- nut confined to power iiai d tool-. It mar he used to test i-\ti ri-inn lord-, extension lights, eleilrii (an-, vending machines, ('i-di-lal grindei-. olhee mnehines. -it-k lamp-. Ili.iu scrubbing and ji~ 11111l: in.n lime-, ami. in fad. am - 111 g 1 e -1 ili.i-i- ririlrii.il dev ice "huh in rive- it- |niwer from a 11 - <-jil.il le. I in idenlallv. the in-11 im lent . iinl.im- receptacles that "ill .n i I'uunoilatr anv tvpc of i h ill n.d i ap. All that is ncccs-ai v i- to operate the three push I 11111111- in proper -equcncc. testing all i ii< mis and watching for the -afe i green light i and unsafe 'red light 1 i imdiliuii-. 1-oealion for l sc The most logical location for u-c o! this equipment is in the tool crib and the test can be performed bv a tool crib attendant. Tools are Naiiono/ Safely News, February, 1953 No. S04.S Wear a Reece "Strong Toe." Ccmfcrtabie leather uppers. High, roomy steel toe pro tector, heat-resistant wooden sole. Have comfort-safe feet at work in oil foundries, steel mills, factories. No. ]00 The Reece "Hot Foot" sandals. Protect your feet in furnace and coke oven rooms. Straps on over your own shoes. Heat resistant wooden soie. strong oalvanized iron counter, flexible hinge toe. Cannot slip. BE SAFE THE REECE WAY WITH A REECE "HOT FOOT' SANDAU REECE WOODEN'SOLE ^SHOECO Dept. NSN 2 Columbus. Nebraska The complete line of aluminum maintenance and con struction equipment . . . built with Louisville patented rung assembly . . . reinforcing and locking the rung to the side rail. In plant after plant Louisville equipment is writing new chapters in SAFETY -- DURABILITY -- ECONOMY. CHECK WITH YOUR INDUSTRIAL SUPPLIER-or WRITE `LOUIS VILLELADDERCOMPANY.su!;<^w\' 1.101 W.OAK ST--DEPT.15 --IQUISVim 10. Kt.' 107 important Innihimcntal considerations which apply almost equally to all fonnclrics. These are (1) buildin" construction and plant layout, (2) general veili iIntion. and (3) housekeeping. building const! uction, especially the Ins out 01 nri.mgcmcnt of departments and equipment, is of priniars conceit) in dust control. Generally, little can lie accomplished in this direction in existing loun111 tcs. Ness foundries, on the other hand, should be so laid out that there is a smooth or natural floss of matci nils. Mechani/niion is important not mils because it mi leases clfiriencs in production, but because it also makes possible mote specific and positive dust temosul. In one case an existing small btass foundts sens teai ranged and mechanised at what management filt ss as tenilic cost. Ness- cases of lead poisoning did not occui, sshcicas thes hail not been uncommon iiefote the tltangeoser. In addition, anil to the pleas ant suipttse ol management, production pet man mote than doubled and the peicemage ol ie]ccis dtopped almost otu hall. \\ alls should be smooth and painted in light colots. I'l o|efl tons exposed beams etc., should be kept to a minimum so that then an lesset plans foi dust to mill it and liimi sshuli it must bi teniosid ton muls h si ii be putt'd loose, f.ooil illumination toils 1 snli 112--Minimi \t Mini n v i ion R s s ton si !s \\n Coxnn toMxr. hot ii-mi \ t I limns 1 t|in|munl K\hmM Ri'(|iiiH'innii 1 i.nufcr Points. . .. . a'iO i fim pci bm of belt \\nlih bin not less ill.in ) Mi fpm nuh.ih. Hkkt[ Elc\ mors. . . IaIuium from cla.iini be.nl ion (fin per s<| fi of cions Nccunn. Vim! Screens . . . , .ll.it ilctk --'U cfm pa *<| fi of Nficcn :iren but im( lews ih.in `Jon fjmi imh.ift C\luulric.il--100 c(m per st| fi of mutii nos* NCdion \olmnc nn\ be doubled 10 pro vide rccjiiiicd fines removal. S.iiul Mullers.......... .130 fpm liirougti openings in dusi hood Smut Bins............... .l.'0 fpm indraft bin noc less limn 0.5 cfm per cu ft of bin capmitv. in speeiling production anil in house kei pine The size of the foimdrs in relation to it' piniiuinon rate has a profound influence on the dnstmess In cause the atmospheric dust concentrations dectcasi a, tlu cross'd mg decreases. Good general, ventilation is important beeau.se all joimdnes have many minor and scattered dust soutees Even if the main dust sources are controlled elli ttneis b\ means of local exhaust anil other specific mcaxuris. good general ventilation is needed, to present the general dust level from rising to undesirable levels. A rule of thumb method for deciding upon mini mum general ventilation requited is 20 an ih.mgcs per hour for mechanized foundries, and 12 an changes per hour for plants that are not mcihnm/cd. When applying this rule, it must be remembered that the general ventilation required varies considciablv from plant to plant. In some instances tlicsc suggested rates will be inadequate. es]>criall\ if the other and more specific control measures are lacking. Relore the dust measurements had been made, all foundries studied were classified nuo three groups as regards the housekeeping in evidence. For the purpose of this classification housekeeping onlv was considered. The approximate average dust lonceiuralions for the molding areas, the shakeout operations, and the cleaning departments (the three departments for which dust concentrations arc reported in each housekeeping class) were 7 mppcf for the good house keeping group: 25 mppcl for the average group: and 152 mppcl for the group classified as poor. Acknowledgments The aiithin wishes to acknowledge the emirtesv of American Air Filter Co.. Inc.. Louisville. l\ Y Rubber Co., New York, and Pangborn Cor))., Hagerstown, Mil., in furnishing the photographs used in the pa|>cr. References I. W. Landau. "Puhnonais Disease Among Cli'.mcis n( Castings Due lo Dust." .Irrii. f. Genet h/mlh. it. Gr:crt bcli\g., i, 112. 1932. Ab'tr. Hull. //vg. i\ 2(1. 1033. 2 \V. Landau, ''Silicosis Among Casting Cleaners." Atrb. f. Gc:eci befttitb. it. Gneerbeb\y,.. -t. .`>13, 1933 Vbsn /lu/!. //sg X. 727. 1933. 3 \V. J McConnell .mil J. W. Fcbncl. "Health Ha/.nils in ilie l omnln Inrtiislis." ]. hut. //yg. lo. 227. 1931 -t. F. M. Waiheld. "Results of Vias Chest txanim.iimns Huong 2.300 Workers in a Hears lmlnstts Plain." hut Med.. /. 302, 1933. vb'ii. j hid. //\g.. ini. 1933 3 |. F. Kells and R. C. Halt, "SilirO'i' in Minlem ronndnes." A t ;r ) 01 k State J. of Med.. 17. 1. 1937. 0 L. H- Osmnnil. "Diisl Ha/aul Among Fonmlrsmcn," Ant. J l/nenl.. iS. 122. 1937. 7. O A. Sander. I lie l.nng Findings m Fnnndrs Workers. A Four Year Survey." Paper read before lnd. Hsg. Section V P. H A. at Gfiili Annual .Meeting. Ness Vmk On. 7, 19.37. S. "Silicosis in tire Foimdrs Industry," Ness' Vmk Stale Dcp'l. of Lalior. Sjtrctal Hn/Utiit ,\n. In7. Stale Ollice Iliiilding. Vlhans. I93K. 9 1 . Hairh. C. F.. Williams and h C. Holm, Diisi Conrcnnaiions in Foundries." The httUtilnnl Diiltctin, IS, 89. (Feb.) 1939. Issued bs Ncsi York State Laboi Dep'i.. Albans. N. Y. 10 |. M. Kane, "Foimdrs Viniilaiion," T/ir Foundry, Fcl). and Mar.. 19IG. II. "Silicosis Prevention--Dust Cimirol in Fmimliics." Cnited Siaics Dept, of Labor. Div. of Labor Siandaiils, 1910 (for sale bs Sup't. of Documents, Washington. D. C.). 12. Allen L). llramll. "Industrial Health Lngmceimg." John Wiles and Sons. Inc.. Neiv York. 19-17. R TRANSACTIONS of the American Foundrymen's Society Proceedings of the International Foundry Congress Atlantic City, N. J. May -1 7,1952 VOLUME 60 Published by the American Foundrymen's Society Chicago, Illinois N 1952 \ m si THE FOUNDRYMAN LOOKS AT AIR POLLUTION By N. H. Keyser* and H. P. Munger* ABSTRACT The air-borne contaminants from a foundry are classified as dust, fumes, and noxious gases. They originate at many points m the foundry. Particle size ts the most important property of solid contaminants. Each foundry finds itself in a different situation because llic nature of the operation differs from foundry to foundry and because location of the foundry is of great importance. The foundryman and the local air-pollution control authorities should cooperate in working out an individ ual program for collecting dusts and fumes, employing the knowledge and research methods at hand. The technical methods for controlling air pollution are fairly well developed. These include dry inertial collectors, and wet scrubbers which have a wide range of efficiencies and also a wide range of costs. Filtering methods and electrostatic pre cipitators an among the most efficient dust collectors. Several newer methods are going through the production development stages. In spite of a number of factors which partially offset the cost of air-pollution control, cleaning air rarely yields a net profit. The actual cost will depend largely on the amount of cleaning required by the local conditions. The public will eventually pay this cost. The Problem The foundryman ha* a definite interest and a re sponsibility in preventing excessive discharge of waste into the atmosphere. But how much waste can be discharged into the air before we say the discharge is excessive or that the air is "polluted"' A few de cades ago, dense clouds of smoke coming from the stacks of our industrial plants were regarded as a sign of prosperity, and nothing short of a dense cloud ol noxious lumes would have been described as air pollution. On the other hand, refreshing cotmtrv air contains wind-borne dust, pollen, and gasses from decaying vegetation. The present trend is to define some concentration of contaminants between these two extremes as ex cessive. Air is regarded as polluted when the concen tration ol contaminants exceeds that which is in jurious to propel ty, to health, or to human comfort. For the most part, theiclore, air pollution is of great est concern in large centers ol industrial activity. Overloading of the ail with tlirt ma\ result from *Battelle Memorial Institute, Columbus. Ohio. 5M0J numerous small sources of contaminants over a large area, or a single concentrated source, or any combina tion of these two conditions. Smoke and fly ash from industrial stacks, railroad locomotives, or the chim neys of homes and schools are the most obvious sources of contaminants. Burning trash and leaves in metropolitan areas, gob piles in coal-mining areas, and the exhaust from Diesel locomotives and trucks or even passenger automobiles also contribute their share of contaminants. It can be seen that the found ry, in most cases, is just one of the many sources of air pollution in a community. Aside from the contribution of the' foundry to the over-all burden of contaminants in an industrial area, the foundry, as an individual industrial plant, has a problem of community relations. When the neigh bors see nothing but smoke pouring from the foun dry, they get the impression that the foundry is a smoky, dirty place. They are inclined to blame their dirty washing on the smoke that they can see, even though the actual source of the dirt may be some dis tance away or perhaps just the general condition of that particular area. One of the problems facing the foundry is that of attracting young men to work in that industry. Cer tainly a reputation for smoke and dirt does not help the foundry solve this problem. Each Foundry is an Individual Control Problem To those who have studied air-pollution problems, it is evident that each plant presents an individual problem. The methods for reducing contaminants must be tailored to fit this individual situation. The municipal and county programs, in each case, form the backbone of air-pollution control. Each com pany within a local air-pollution control district should work out its own program in cooperation with the local air-pollution control engineer. Any program of air-pollution control should make the widest use of the knowledge that is available. The first information required in setting up an individual program for the control of air pollution is a knowledge of the physical and chemical nature of the contaminants emitted into the air, especially 364 ; their particle-size distribution. The concentration of the contaminants and the points at which they leave the plant also need to be known. Other important factors are the natural surroundings of the plant and locauons of population centers and farms. Of equal importance are the atmospheric conditions under which the contaminants are found objectionable. in the dispersion of air-borne contaminants, the nature of the country and the atmospheric condi tions play major roles. Flat country, especially near the Great Lakes where strong winds are frequent, favors the rapid dispersal of dust, fumes, and nox ious gases. Narrow, deep valleys furnish pockets in which contaminants may collect to form relatively high concentrations. Temperature inversions which form over pockets in the land stabilize the air and prevent the normal vertical dispersion of contamin ants. A temperature inversion is a condition in which the air at ground level is colder than the air above it. Los Angeles county is an outstanding example of the influence of the nature of the land surface and atmospheric conditions on the buildup of contami nants over an industrial area. In Los Angeles county, a large concentration of industry is situated in a basin surrounded on three sides by mountains. Tem perature inversions, in effect, put a lid on this basin. Because they cannot get out of the basin, smoke and fumes and noxious gases frequently build up for several days. Fogs, rolling in from the ocean, com bine with the concentration of man-made contami nants to create a powerful eye-irritating smog. It is be cause of this set of conditions, which are abnormal for most of the rest' of the country, that the air-pollu tion standards for Los Angeles must be so rigid. Devices tor Analyzing Air-Borne Contaminants There are well-established technical methods for determining what are the air-pollution problems of any individual industrial plant. These methods util ize devices for collecting and analysing, the air-borne contaminants. Analysis of an individual foundry's contribution to air pollution can be made right at the source. For example, the amount and nature of emissions from a cupola can be determined. Measure ments of dirt falling on the surrounding community also can be made. A new device, developed at Battelle, not only determines the amount of dirt fall but also establishes the direction from which dirt is com ing! a knowledge of the direction from which the dirt is coming is of special interest in determining whether the contaminants are of local origin or have been blown in from another area or community. Devices for measuring the influence of the surface of the land and the atmospheric conditions on the dispersion of contaminants are also in use. For stud' just above ground level, instruments have been attached to fixed structures. A new technique uses a kite balloon to carry weather instruments and air sampling devices up to altitudes of 500 ft or higher 1,5,1 In highly industrialized areas, these methods provide the tools for securing a three-dimensional picture of contamination of the air. The 'Nature oi Air-Borne Contaminants An effective program fof controlling air pollution from the foundry must be based on a knowledge of the origin and nature of the contaminants that are emitted into the air. It is customary to divide the contaminants into four principal classes: (I) smoke. (2) dusts, (5) fumes, and (4) noxious gases. Smoke is defined as the solid or liquid particles resulting from incomplete combustion of organic materials. Soot is an example. Dusts are solid particles of anv nature which have been produced bv mechanical pro cesses and released into the air. Particles oi iron and abrasive from the grinding of castings are typical dusts found in the foundry. Fumes are solid or liquid particles in die air, commonly generated by sublima tion, vaporization, or chemical reactions. The white fumes liberated during the baking of cores, and the brownish fumes which arise from hot iron or steel are typical examples of fumes in the foundry. Sul phur dioxide and carbon monoxide are typical nox ious gases with which the foundryman is familiar. Probably the most important property of contam inants is their particle size 4 Particle size coupled with density and shape determines the distance contami nants will travel in air before they settle to the ground. Visibility of contaminants is determined by the number and size of the particles in the air and by the degree to which moisture condenses on the par ticles to form fog. Finally, the particle size of the con taminants determines what methods of sampling and analysis can be used for studying the air and7 what type of equipment can be used for separating the con taminants from air, and for their subsequent disposal. In view of the importance of particle size in airpollution control, the foundryman should have an idea of the size of particles involved. The size of smoke, dust, and fume particles is commonly expressed in terms of the average diameter of the particles mea sured in microns. A micron is 1/1000 of a millimeter, or 1/25,400 of an inch. The size of particles in the air may range from over 1000 microns for raindrops to considerably less than 0.01 micron for sulphur di oxide and other gases. Several other examples which are useful in visualizing the size of the particles arc: (I) a 30-mesh sand has an average diameter of 295 microns, (2) a 325-mesh silt has a diameter of 44 microns, (3) the smallest particle visible to the naked eye is 10 microns in diameter, and (4) the particles in tobacco smoke have an average of about 0.3 mic ron. Particles below 1 micron in diameter tend to stay suspended in quiet out-door air almost indefinitely, whereas those larger than 1 micron tend to settle at a more or less rapid rate. In agitated air, such as found in foundries and other industrial plants, par ticles 10 microns or larger in diameter may stay sus pended in the air for a considerable length of time. The range of particle size for a number of indus trial dusts and fumes is shown by means of bars in Fig. 1. Foundry dusts include such coarse particles as the cinders and other debris blown out the stack of a cupola and the finer dusts from the foundry I 366 The Foundryman Loors at Air Pollution PARTICLE SIZE-MICRONS Fig. 1 --Particle Size of Industrial Aerosols and Equipment for Cleaning Gases shake-outs and cleaning room. Metallurgical fumes comprise such contaminants as the brownish fumes coming off the electric or open hearth, and that part of the cupola and the non-ferrous-melting furnace emissions resulting from volatilization and oxidation of the metallic constituents of the charge. It is apparent that the foundryman must con tend with the entire range of particle sizes considered to be air contaminants. For the sake of economy in controlling the air contaminants, the foundryman should use the type of collection equipment that will do each job at the lowest cose The particle-size ranges for which broad classes of collecting equipment are effective are shown in the lower half of Fig. 1. Additional details on collect ing equipment are given in a later section. Source of Contaminants Air borne contaminants come from many points in the foundry. In many cases, the melting department is a major source. In fact, the melting department has been the first to attract the attention of air-pol lution control authorities in many cities. The electric furnace and open hearth for steel and iron melting emit clouds of reddish-brown fumes, especially during melt-down when the charge is not protected by the metal is at its maximum temperature. The advent of the oxygen boil in steelmaking has aggravated the fume problem. The open-top cupola belches forth a stream of hot gases clouded with solid particles. The coarsest par ticles are the size of coarse sand. The finest particles must be viewed with an electron microscope to distin guish them. Coarse particles settle on the foundry roofs, yards, and on the foundry's immediate neigh bors. The finer particles drift away to settle at some distance from the foundry. Sulphur dioxide, formed from sulphur in the coke, and unburned fumes from oily scrap add their characteristic unpleasant odors. A typical sample of the cupola stack-gas emissions will contain on the order of 35 per cent of its par ticles in the zero to 5-micron range and about 50 per cent of the particles will be over 44 microns (325 mesh). The remaining 15 per cent will be spread out over the range of 5 to 44 microns. The concentration of particles above 44 microns (325 mesh) is chiefly dust and debris consisting of broken coke, fine metal chips, rust, sand, and dirt, which are picked up by the rising gas stream and carried out the suck. The particles in the 0 to 5-micron range are chiefly fumes from the volatilization and oxidation of iron, silicon, manganese, and certain tramp elements by the in- N. n. tijc.rn.ii. AfiU n. r. -------------- ;' . - largely responsible for the opacity or color .of the suck gases, primarily because there are so many par ticles in a given weight of fume as compared to a given weight of the coarse particles. It takes 1000 Darticles, 1 micron in diameter, to weigh as much as one particle 10 microns in diameter. The core room also is a major contributor of fumes in the atmosphere in and around a foundry. Fumes given off from core oil and cereal binders during the baking of cores are pungent and irritat ing. A host of obnoxious compounds have been identified in the fumes given off by linseed oil dur ing drying. These include acrolein, formic acid, ac. etic acid, acrylic acid, butyric acid, carbon monoxide, and a number of other volatile products.* Presum ably, many of these same compounds are generated during the baking of cores and also during casting and shake-out of molds containing cores. No entirely satisfactory substitute for core oil has been developed which does not give off fumes and odors. In some cases, the odors of the substitutes were more obnoxious to many foundrymen than the odors from core oil. The shake-out and cleaning room are also sources of large quantities of fumes, dusts, and noxious gases. In the shake-out, large quantities of hot sand are suddenly exposed to air. Particularly where many cores are used, large quantities of fumes and noxious gases are generated by the incomplete combustion of organic materials in the mold. Added to this burden are fine sand and binder materials thrown in the air by mechanical agitation used to shake the molding material off the casting. In the cleaning room, the problem is mostly one of dust generated by such op erations as chipping, blasting, and grinding, although metal and other fumes do arise from welding opera tions. Miscellaneous sources of air contamination in the foundry are open fires, handling of dry sand before it is tempered, parting agents, metal fumes from the ladle during transfer and pouring, and mold gases. The foundry pattern shop also has its dust-control problem. In this case, however, the materials involved are woodworking shavings, chips, sawdust, and, if metal patterns are used, there is the possibility of metal and abrasive dust. Methods for Control The industrial hygienists have developed excellent methods for reducing the concentration of contami nants in the air within the foundry. They have ap proached the problem from several angles, among which are (1) to prevent or to reduce the production of dust, fumes, or noxious gases, (2) to reduce the use of materials which give rise to dust, fumes, and noxious gases, (3) to provide personal safety equip ment to prevent inhalation of dust, fumes, or noxious gases, and (4) to extract the dust and fumes from the various points in the plant where the contaminants are generated. The extracted dust- and fume-laden air may be exhausted directly into the atmosphere outside the foundry. If the burden of dust and fumes of this air is great, the air must be passed through an air cleaner to avoid air-pollution problems. The foundryman is then faced with making a decision as to what type of dust collector to use. Control of air pollution starts with the dust hood and ducts to convey the dirt-laden air to the collec tors. Much good engineering has gone into dust hoods and ducts. Since the principles are well known, the subject will not be discussed here except to men tion one of the problems encountered in the foun dries that have applied dust control to existing plants. In most instances, space is at a premium, and dustcontrol equipment must be built into extremely lim ited space. This leads to a temptation to use hoods, piping, and collectors of inadequate size. Available Types ot Dust Collectors The technical methods for cleaning dirty air and gases discharged into the atmosphere are fairly well developed. The proper selection and application of cleaning equipment depends on a knowledge of the types of collectors available and their performance. Dry inertial collection methods are the most econom ical but have definite limitations. These methods de pend on gravity or the momentum of a particle to carry it out of the gas stream. In its simplest form, the dry collector is merely a settling chamber or an enlargement in the duct carrying the dust-laden gas. Practical limitations on the size of such chambers do a not permit designs with low enough gas velocities to extract fine particles. The minimum particle size normally collectible in a settling chamber is on the order of 40 to 80 microns, depending on the design. The cyclone collector is a widely used collector of the inertial type. By introducing the dust-laden gas tangentially into a circular chamber, a centrifugal motion is created which throws the dust particles to the side where they deposit, or drop to the cleanout in the bottom. Decreasing the diameter of the cyclone makes the gas travel in a tighter circle and increases the centri fugal force for throwing the dust out of suspension. The small-diameter cyclones, therefore, are more ef ficient where particles in the smaller size range are encountered. On the other hand, because of rebound of coarse particles, the collector may not be as effi cient for removing particles of large size. Multiple units of small-diameter cyclones are required to handle a large volume of gas. A large variety of makes and configurations of cy clone collectors is commercially available. In gen eral, however, the collecting efficiency drops off rap idly for particles below about 20 microns in diam eter for the large-diameter cyclone and below 10 mi crons in diameter for the small-diameter multiple cyclones. In addition, the collecting efficiency is prac tically nil for particles below 5 microns for simple cyclones and 2 microns for multiple cyclones. This, of course, limits the type of dust that may be col lected. Efficiencies in the neighborhood of 97 per cent have been reported on coarse material, such as saw dust from planing mills.' In contrast, they may 368 collect only between 10 and 25 per cent of the solid material in stack gases from a boiler.7 In many cases, where it is necessary to install addi tional exhaust fans, or where space is limited, a mech anical centrifugal collector will be found practical. This type of collector uses a high-speed impeller to provide the centrifugal force for throwing the dust out of suspension. The impeller also acts as a fan for drawing the dust-laden gas through the cleaner. At the point of greatest concentration of dust, part of the air is skimmed off and carried to a settling chamber. After depositing the entrained dust, the air is recirculated in the system. Louver and dry skimmer collectors also depend on inertia for throwing the dust out of suspension. Inertia concentrates the particles of dust in the small end of a slotted metal cone. About 90 per cent of the air passes through these slots to the blower and stack, while the concentrated suspension passes into a small cyclone. The exhaust from the cyclone is recycled in the concentrator. Centrifugal Separators and Louver Collectors Both mechanical centrifugal separators and louver collectors have application for collecting particles in the size range collected by cyclone separators. Dry inertial collectors, as a class, are not suitable for collecting fine dust (particularly particles below 10 microns in diameter). They are satisfactory, however, as rough cleaning devices for reducing the load on high-efficiency final collectors with which they are frequently used. On the other hand, as final clean ers for coarse, non-toxic materials, such as wood or metal chips, they do an excellent job and are simple and inexpensive. These collectors can be built to handle relatively hot gases which makes them emin ently suited for such applications in cupolas where merely the removal of the coarses particles from the stack gas is sufficient to satisfy local conditions. When dry inertial collectors are inadequate, it is advisable frequently to go to one of the wet collect ing methods. Wet collecting methods depend on a simple process of washing or scrubbing die dirt out of the gas and wetting the particles to" increase their effective diameter so they mav be untuned bv simple loliectors, such as a cyclone. In addition to remov ing dust, wet collectors also can returnsulphur gases which may sometimes be important. Static Spray Washers The simplest form of wet cleaner is the static sprav washer which may be seen mounted on the top of manv cupolas. This equipment can remove 50 to 75 per cent of the solid matter and a portion of the SO- in the cupola effluents. However, a Jarg^ portion of very fine solid particles escape. Wet scrubbers are more efficient in removing the smaller size particles than are the simple spray wash ers. Wet scrubbers depend on mechanical means of admixing a spray .of water with the dust-laden gas. They empiov the cyclone, rotarv centrifugal collector .............. '.... ..................... ................................ i. '' The Foundryman Looks at Air Pollution Roughly speaking, the efficiency of these scrubbers is related to the work applied to admixing the water and gas. Scrubbers can be very efficient and give very clean gas. Because of the high power require ments for the highly efficient scrubbers, it is custom ary where very clean gas is required, to use a scrub ber of moderate efficiency, followed by other types of final cleaners which require less power. The wet cleaner reduces the load and, at the same time, cools the gas. Cloth filters or bag houses are becoming a more familiar sight around the foundry. They operate on the same principle as the vacuum cleaner in the home. They have been applied to cleaning the ex haust from the shake-out and cleaning rooms. In similar applications, they have been found to oper ate with dust-collecting efficiencies of over 99 per cent. It has been only recently, with the develop ment of the glass-cloth bag which will withstand temperatures up to about 500 F, that bag houses have been utilized for the difficult job of cleaning the hot gases from the. cupola. They have been found to satisfy the difficult requirements of the Los Angeles County Air Pollution Control District.1 All material passing through the cloth filter is below 5 microns. Efficiencies are good on particles down fo a fraction of a micron. Bag houses are limited, however, to applications where there are no condensable fumes or gummy materials presenL Electrostatic Precipitators Electrostatic precipitators are probably the most efficient of all collectors. Collecting efficiencies are very high on particles down to a fraction of a micron. Although electrostatic methods do not remove gases, there seems to be no lower limit to the size of solid particles that they will remove. Electrostatic precipitators employ up to 75,000 volts to induce a negative electrostatic charge on the sur face of the dust particles. The dust particles are then repelled to the positive electrode, which is con structed to serve as a dust catcher. Among the newer methods for collecting dust and smoke are the sonic agglomerators.*-10 Sound waves cause the small particles of dust to vibrate, thereby increasing the number of collisions between particles. Upon collision, surface forces on the particles of cer tain types of materials cause them to adhere to one another. Through a series of collisions and adhe sions, small particles agglomerate to such size that they can be removed from the gas with a cyclone separator. The method is limited to very small par ticles, as are lound in smoke, and it does not work on all materials. Further developmental work is required before its possibilities in the foundry are known. One of the latest improvements in wet collecting equipment is the Venturi scrubber.11 In this scrub ber, water is broken up into a very fine misL The mist and gas pass through the venturi portion of the collector where the very small droplets wet and ab sorb the very small particles of dust. A cyclone sep arator then collects the wetted particles and drops i t t . i N. H. KEYSR AND H. t. MONGER Control of Combustible fumes . Combustible fumes can be destroyed by oxidation or combustion. Where the ratio of combustible ma terial to air is high^enough, as. in the cupola stac^ gases, combustion will be selftbstaining once it lias been started. An ignitor is sometimes used for ignit ing the gases during periods when they do not ignite freely. Lean mixtures, which will not maintain com bustion, must be heated to temperatures on the order of 1200 to MOO F, to complete the oxidation. In some instances, fumes from the baking of cores have been reduced by recirculating the air in the oven through the burners. One of the newer methods for oxidizing combus tible fumes is the catalytic combustion process. Very dilute mixtures of combustible vapor or gas will oxi dize at temperatures as low as 350 F, or less, in the presence of a catalyst. This principle has been ap plied commercially to the oxidation of a number of fumes and gases, including the fumes from the bak ing of cores. Of special interest is the fact that the heat obtained from the oxidation of these fumes is returned to the oven to reduce the amount of out side fuel required to keep the oven hot. The Cost The purchase cost of dust-collecting equipment ranges from something less than |100 per 1000 cu ft per min treated for simple cyclone separators, to 51000 or even more for certain of the very high effi ciency collectors, such as bag houses, electrostatic, or disintegrator-type washers.12-13 Power consumption may be as low as 0.1 kw per 1,000 cu ft per min for simple gravity settling chambers, to as high as 10 kws per 1,000 cu ft per min for high-efficiency scrubbers. These figures are for total power, including electrical energy, water-pumping power, power for necessary auxiliary equipment, and pressure drop through the apparatus. One thing that must not be overlooked in estimat ing the cost of dust-control equipment is the actual volume of gas handled. The more gas handled, of course, the larger the size of collecting equipment required. In the design of dust hoods, for example, sufficient excess air must be drawn through the equip ment to flush all the dust-laden air from the source. The equipment must clean all this air plus any excess that is taken in. Cupola stack gases are another ex ample where the volume of gases emitted is greater than may seem at first. The volume of gases gener ated by a cupola may be 2 to 4 times the volume of air blown into the tuyeres. Burning of the gases in the stack and aspiration of air in the charging door may increase this volume to 5 to 7 times that of the tuyere air. Cooling of these gases before thev are passed through the dust collectors, of course, re duces considerably the volume of gas that must be handled. Nevertheless, the volume that must be handled is more than the volume of air blow-n into the tuyeres. Who pays the cost of clean air? The answer to this is simple and one which everybody should know. The cost of clean air is eventually paid by the publid This degree that air pollution is controlled in the future will depend largely upon the amount the pub lic is willing, to pay for controls in terms of increase of cost of products. .. Thematerials recovered in the air-cleaning opera tion seldom have much value. There have been fig ures published on the large savings in nonferrous smelting operation by collection of the dust from the Hue gases. For example, it has been estimated that S27,000.000 worth of metals have been recovered in the copper industry- alone.'-* Unfortunately, in the foundry industry, in general, the products recovered in the dust collectors are not nearly so valuable. For the most part, they may be classified merely as dirt which has to be hauled off to the dump. Fly ash collected from the cupolas may have some value as a filler for concrete. However, it probably must sell for considerably less than concrete itself. It must be used close to the source and must be avail able in quantities large enough to be worth handling. Recently it has been found that fly ash makes a cap able pipe eliminator of the non-exothermic or insul ating type to apply to the surface ol feeders on cast ings.15 This would permit the foundry to consume its own fly ash to some advantage. For the most part, the small quantities of salvagable material involved make the cost of handling more than the products might be worth. It seems. hardly worthwhile to develop a useful market for them. Other opportunities to realize some return on the investment in dust collectors are difficult to evaluate in dollars and cents until the equipment is installed. The factors which may partially offset the cost of clean air are: (1) reduced maintenance, for example, less frequent cleaning of the roof, (2) better working conditions and workers' morale, and (3) better rela tions with the neighbors. The last two factors should help attract better workers into the foundry and re duce labor turnover. The by-products and other benefits derived from gas cleaning rarely yield a net profit on the entire cost of the gas cleaning operation, but they may help materially to reduce the expense. Bibliography 1. H. P. Munger. "The Engineering Approach to Air Pollu tion,- presented at The American Public Health Association, San Francisco. California, November 2. 1951. 2. H. P. Munger. "Present Sutus of Air-Pollution Research." Mechanical Engineering, vol. 73, no. 5, pp. 405-411, May, 1951. 3. H. P. Munger. "Meterological Methods for Studying Air Pollution." presented at the XII International Congress of Pure and Applied Chemistry, New York, September 10-13. 1951. 4. H. P. Munger. "The Spectrum of Particle Size and Its Re lation to Air Pollution," presented at The First U.S. Technical Conference on Air Pollution. Washington, D.C., May 3. 1950. 5. W. M. Lord, "Foundry Cores and Moulds: Vapours and Fumes Evolved From Organic Bonding Materials." Iron and Heel (London), vol. 23. January. 1950, pp. 21-25. 6. R. Dennis, C. A. Johnson, M. \V. First, and L. Silverman, "How Dust Collectors Perform." Chemical Engineering, vol. 59, no. 2. pp. 196-197. February, 1952. 7. A. J. Crindle, "Dust, Fume and Smoke Supression." pre sented to Iron and Steel Engineers, Cleveland, Ohio. September 370 26. 1950, and reprint by Whiting Corporation. g. p. Siechcrt and H. B. Menardi, "Clast Bags Clean Cali fornia's Air," The Iron Age, vol. 169. no. 4. pp. 78-80. January 24. 1952. 9. H. W. St. Clair. M. J. Sendlove, and E. V. Potter, "Agglo meration of Smoke. Fog, or Dust Particles by Sonic Waves." Industrial and Engineering Chemistry, vol. 41. pp. 2434-2438 (1949) . US. Bureau of Mines. R. 1. 4214. 10. H. W. Danser and E. P. Neuman, "Industrial Sonic Ag glomeration and Collection Systems." Industrial end Engineer ing Chemistry, vol. 41, pp. 2439-2442 (1949). 11. H. F. Johnstone and M. H. Robenj, "Deposition of Aerosal Particles From Moving Gas Streams," Industrial and En gineering Chemistry, vol. 41, pp. 2417-2423 (1949). 12. C. E. Uapple. "Processes Use Many Collector Types," Chemical Engineering, vol. 58, no. 5. May, 1951, pp. 144-151 . 13. O. T. Zimmerman and I. Lavine. "Chemical Engineering Costs." Chapter 12, Dust Collecting Equipment, p. 209, Pub lished by Industrial Research Service, Dover, N. H. (1950). 14. H. V. Welch. "Fume and Dust Problems in Industry," Transactions, AIME, vol. 185, p. 934 (1949). 15. "New Foundry Techniques: Pan 2," Canadian Metals, vol. 15. no. 2, February. 1952,' p. 27. The Foundryman Looks at Am Pollution DISCUSSION Chairman: F. W. Shipley, Caterpillar Tractor Co.. Peoria. III. Co-Chairman: J. R. Allas, International Harvester Co.. Chicago. Recorder: H. F. Scoetr, American Foundry man's Society. Chicago. Orville Laais1: Which type of dust and fume collector is preferable, the dry or the wet type? Ma. Keysek: Foundry men should use whichever type dust and fume collector is necessary to meet local air pollution ordinances. Use the dry type if possible because of its lower maintenance costs. K. M. Morse*: What data can you give us on the site spectrura of cupola emissions. Mr. Keyser? Ma. Keyser: About 50 per cent of the particulate matter emitted is dust larger than 44 microns. Approximated 35 per cent is metal oxides 5. microns and smaller. Very little matter between 5 and 44 microns is emitted. sDiractor of Personnel, Universal Foundry Co., Oshkosh, Win. 'Industrial Hyficoist, U. S. Steel Co., Pituburxh. * v - -- m . tmmrmrn fetumdrymaetm Svptvinhvr 10X2 j Volume 22 * Number 3 Official Publication oj the American Foundrumen s Society A JC..T 4 6. A t V t elyi i f Soiling an external core for a 50.000lb 4-j;ope centrifugal blower casimg at Ch.unbcrsburg Engineering Co Chambersburg. Pa The finished mold--entirely cement-bonded sand --ccnsi^u of a bed. a semi-cyhndric.i! core with a separate nozzle core ru each end. and four external cores Alieady m place is one of the nozzle vores tdark colored). At the start. - bed of cement sand is levelled in frame containing core prints The sLim-o Imdncal core is rammed in piace in h box assembled on the bed. Cores are aligned using gage lines on the bed and a level. All compound surfaces arc carefully gaged during assi-maly to insure specified wall thicknesses. Publications Committee H M Si. John, Oifliminn C ane Co.. Oucaf# C. H. Coftg laittiie Ktmoujl iMlitirle W. 0 McMtlion iMMnii-cflii Niirntcr Co.. Cfticac* H J. Rowe i.grmnu'n Co ol Amcnc* Mtsbur(fc F J Well* murnjlioral Mtchrl Co . Ootfiil A.F.S. Headquarters G 1C S. Mn'kuja n, Chicago J Wm W Moloney Secret cry-Treasurer S C Mouori, 7rr>iu>rol !>>rcclnr American Foundryman H f. Scobie, Editor Paul Fountain, ^itislnnf F.diior *eriy Koeller, /tdrcrfisuuj Afnunurr Helen Owdek, Adrrrls;iif< Production loVerne lohn, CirruIrtNou Advertising representatives Centrol K E Clparv Conimcrcint d Sarinpr Bank- Bldg , Berea. Ohio Berea J-77J9 Midw.uern H Thorpe Covneton Co . (-<* X Mir)nnon Ave . Chicago Superior 7-&054 Eastern r.oocrt B Weston. 550 Fijlh See , Xeir York, X V. P'-aea 7-0454 33 Toward higher productivity 3-1 The job record card, a valuable tool lor the jobbing foundry R. IV. Griswold 37 Small foundry, small castings 44 The non-ferrous cleaning room Alurtm G. Oifti 59 Causes of hot tears in steel 65 Design-production teamwork in the steel foundrv J. O. Fell 40 Foundry crucible service life R. A. Hetndl 53 The truth about disease caused by foundry dusts O. A. Sander 56 Are technical graduates getting adequate training in college? Hirnvi Brown 50 1953 A.F.S. Convention 55 Directors set financial policies 63 S &: H &. AP progress report 6S Regional conference programs 71 1953 European foundry tours 104 News of technical committees 27 Foundrijmcn in (lie neuis 90 A.F.S introduces 95 Chapter officers and directors 17 Products and processes 18 Free foundry information 87 Abstrncts 92 Book reviews 72 Directory of A.F.S. chapters 75 Chapterncws 97 Rammed up and poured 106 Foundry tradenews 112 Coming events 114 Advertisers' index 115 Classified advertising Published monthly by the Ameri can Koundrymens Society. Inc.. 616 S Michigan Ave.. Chicago S Subscription price in the U.S . Can ada. and Mexico S3.00 per year, elsewhere. SC OO. Single copies 50c. Entered as Second Class Matter. July 22. 1938. under Act of March 3. 1879. at the Post Office. Chicago. September 1952 3 Technology : "K.V.'U-- . The truth about disease caused by foundry dusts This paper--by the man credited with having done most to separate fact from fiction in the field of dust-caused dis eases in the foundry---was given at the foundry Health Conference held at Ann Arbor, Mich., on April 11-12, 1952. It and all others presented at that time have been compiled into a 200-page publication. Health Protection in Found ry Practice, published by A.F.S. o. a. sandei: / Industrial Medical Consultant. Milwaukee, Wis Although others may soon replace it at the top of the list, silicosis has tor almost a century been the prin cipal occupational disease caused by foundry operations. There are still tar too many foundries producing this entirely preventable disease. On the other hand, more and more foundries have developed dust con trol to such a decree that it has not caused any silicosis in their employ ees for many years. This is the goal toward which all of us are working. Terminology Silicosis is readily defined as a tibrosis of the lungs resulting from '-he inhalation of dust containing free s`hca it offers little grounds for misunderstanding Pneumoconiosis, or. tne other hand, has caused more deimition tioublc than all the others out together, yet gcnencally it is the amplest to define It simply means, dust m the lungs". There is no lin- `'ication of what tiie dust is or Apetner or not it causes reaction h is a snorteninc of Zenker's ong- ;na- term, "pneumonoconiosis" which '*'t` proposed in 183(1. Therefore there mould be no implication of fibrosis tne term because we now know Zer.Ker did not) that there are umcrous dusts which are entirely "',-rt 'vr|en aeposited in the lungs, , m1 cn a0 not Cause irritation or ' ' sis and which do not predispose 1 tuoeieuiosis These have been "vu !n,, "benign pneumoconioses" fterentiate them from the Jy otic pneumoconioses , |.L',i'causc pneumoconiosis is a gen- ' uv ' C: and coveis all dusts ov not. 't should ; n place in occupational disease s Theie the terminology should Dust exposure at shake-out and other dust-producing operations can be readily minimized by appropriate hoods, forced exhausts, and other devices, whether the operation is manual or powered. Establishing healthy conditions is only the first step in combatting the industrial silicosis problem as it exists today. be specific and only those pneumo conioses which may result in impair ment of lung function should be in cluded--silicosis and asbestosis. Pathological aspects Foundrvman's silicosis is a modi fied silicosis. The fibrous nodules seldom are the classical whorlcd spheres resulting from pure quartz exposure The old sandblasters had those bcfoie they used positive pres sure helmets Today's foundrymen are exposed to far less quartz (or free silica) dust than they are to iron and carbon dust. Dust in typical foundry atmospheres seldom con tains more than 20 per cent free sil ica. with iron dust running from 60 to 70 per cent and carbon dust from 10 to 20 per cent. With such atmospheres and with the total dust counts sufficiently high, a modified silicosis may result m which the fibrous nodules develop more slowly, if at all; they always are more irregular than with free silica alone, and secondary emphy sema does not occur around them. There also appears to be less suscep tibility to tuberculosis than with the classical quartz fibrosis. It is because of these modifying dusts already present in foundry at mospheres that the author docs not recommend the use of aluminum dusting. Workers are already getting the maximal benefit from modifying dusts without adding another modi fier. The goal is to continually reduce the silica percentage along with total dust dissemination, not to add other dusts to the air. Functionally, silicosis becomes a disease only when it is advanced or when it is complicated with tubercu losis. W'lth early discrete nodular fibrosis, there is no interference with the exchange of gases across the al veolar membrane, and no loss of elasticity of the lungs. Only when September 1952 53 t i i i fibrotic nodules become confluent and massive fibrosis and secondary emphysema result is there a measur able impairment of lung ventilation. Witnesses for this are the thou sands of foundry workers with min imal silicosis who daily do their hcavv physical work without diffiultv and who show entirely normal ventilatory values with function tests. Exceptions are the occasional individuals with very little silicosis and high-grade obstructive emphy sema. These usually are the older workers who have a naturally de creasing elasticity of the lungs com bined with long-standing chronic bronchitis, bronchiolitis, or asthma, the bronchial irritation often having been caused by excessive smoking plus chronic sinus infection. These cases cause the most med icolegal difficulties because they have real ventilatory disability which most doctors truly believe is entirely due to silicosis. Statistical studies on the incidence of emphysema in the gen eral population at various age levels will help solve some of these diffi culties. Such studies are currently being made. However, still more necessary is the constant realization that minimal silicosis never is dis abling except when associated with tuberculosis, with a continuing pro gram to educate the medical profes sion to these facts. Iron dust in the lungs Another factor in loundrymen's silicosis which bears constant repe tition is the non dust which all foundry workers have deposited in their lungs That these iron collec tions contribute to the x-ray pattern of the silicosis is seldom considered in evaluating the decree of develop ment of a case. The amount of non in the lungs min vnrv all the way from the mini mal and probably negligible traces m moldcrs and coremakcrs to the moss collections in weldors, burners, and grinders. Some of the latter may have nodular x-ray patterns due to the non alone which are radiologi cal ly indistinguishable from silicosis. For this non pigmentation, Zenker's term "sidcrosts" is perfectly proper, provided there is no implication of fibrosis in the term. Sidcrosts is as benign a form of pneumoconiosis as could be desired. It causes neither fibrosis, irritation, nor progressive tuberculosis. Yet it is being misdiagnosed as silicosis every day. and workers so affected, with or without minimal silicosis, all too oTfcn' arc being advised by their doctors trf leave their trades. The fear caused by such well-meant but ill-considered advice has caused more disability than has silicosis it self, in the opinion of the author. Think of iron first The author also believes that the time has come to think first of iron when evaluating the nodular x-ray patterns of foundry workers, even when there is no doubt about there being some silicosis present as well. The first question should be, ``Hew much of this nodulation is due to iron collections?" While the answer is not always easy or possible, it makes for far less pessimism in the prognosis when one can say that a considerable part of the nodulation is probably due to iron. The industrial hygienist has the very important job of making foundry' atmosphere increasingly safe for the continued employment of the workers. Industrial physicians, on the other hand, have the equally important job of making these work ers feel secure in their chosen trade. Workers must be assured that their lung changes will not progress to a dangerous stage with the im proved dust control. New employees with minimal and uncomplicated silicosis or siderosilicosis must be ac cepted without hesitation and so placed that their minimal changes will not increase materially. Where this has been done it has been a major factor in helping solve the silicosis problem. Industrial commissions, no matter who the personnel, cannot be ex pected to consider minimal silicosis as non-disabling as long as foundries consider such workeis unemploy able. The unhesitating hiring of af fected workers would be a major step in the light direction. There is no reason why minimal silicotic workers cannot stay on their jobs and new workers with minimal changes cannot be hired in foundries where dust control has improved to such a degree that new eases of sili cosis can no longer develop. Reassurance, optimism The time has come for reassurance and optimism in dealing with this problem, and the medical profession must be the first to recognize this. Such optimism is only impossible in foundries which are still producing silicosis cases; their first step must be to correct the offending dust pro ducers. Foundries that arc safe for any worker must change their em ployment practices and allow almost anyone to work m them There must be less concern about potential future liability cases, and less rejection of workers with min imal lung changes The daneer of tuberculosis developing in a silicotic lung later in life has diminished al most to the vanishing point as the opportunities for contact with active cases of tuberculosis decrease. Moreover, workers with minimal changes acquired over a period of years will not progress to a more advanced stage of silicosis it properly placed and protected. It seems much sounder to take a chance with work ers having a minimal amount of sili cosis than to make them unemploy able and semi-invalids. Few offending foundries Even though relatively few found ries today are still producing new cases of silicosis, a considerable number have old employees with varying degrees of silicosis who had their significant dust exposures many years ago. It is from this group of older workers that most of our disabled advanced cases arise. Unfortunately, however, from time to time real cases develop in younger workers, and these special hazards need special attention. Large steel foundries, for example, make large and complicated castings with diffi cult cleaning problems. Cores fre quently cannot be blasted or washed out, but must be dug out with pneu matic hammers. These operations have been the main silicosis pro ducers. but have been largely solved by the development of larger and more forceful hydraulic blasters. While the first step is to so control dusty operations that silicosis cases no longer will develop in anyone, that is not enough to solve the prob lem. Those who already have some silicosis must be allowed to continue their chosen work, not only for their former employers but for new em ployers as well. They must be reassured by indus trial physicians that they are not as suming undue risks by continuing their trades, which makes medical control of equal importance with engineering control. In fact, it must be a joint program with mutual co operation between the engineer and the doctor. With such a team, any silicosis hazard can be adequately controlled provided the will to do the job is there. 54 Amcriccn Foundrymon Sk-Ss ,* - <r---, r - ,* k -:. . J ss-.tA;,Aiw;**V;*-*-*h*:r* Practical Aspects of Dust Suppression I'AHT I Bv W. B. LAWRIE M.Sr.. K.R.M.5.. A.I.M. TNCIMKYfAL generation of -*- large quantities of dust is a feature of many industrial proc esses. In some, the dust is danger ous to health: in others, although perhaps innocuous, it appears in objectionable quantities. Higher output often increases the density of the dust cloud generated, so the modern factory may aggravate the <lu-l problem. The term "dust supression" in cludes all methods by which at mospheric dust concentrations are reduced. These methods fall into two main groups. One approach aims at prevention of dust genera tion. The other is directed to the control of dust clouds which have been allowed to form. The former, which mav be ilem ribrd as thisl elimination, is alwavs the better and often the more ,liliii ult method. The latter, referred to a- thul itniirnl. is never so good, although it mav be the onlv practical ex|o .ii< 11. It i. however, of great prailieal importance to keep in n 11 ml these fund.imental differ. in e- m te< himpie. I>||-1 -upri '-'ion i an be applied in I liree n .ivI iist and be-l )- el i ii on.it ion of the dti-lv priue--. T11e 'ci olid i- alleialion of the jiroi-e- giving rise to the dust, so that less dust is produced. This is not so good a* complete elimina tion. but it reduces the amount of dust to be controlled, and so facil itates application of control meth ods. Finally, the dust cloud may be controlled after it has been al lowed to form in the atmosphere. inhere no alternative is avail able. control methods will have to be applied. In the over-all design of a dust supression svstem. however, they should alwavs be considered last. Success often depends on the thoroughness with which the first two methods have been used, and the degree to which the actual for mation of the dust cloud has been restricted before the control meth ods were applied. Although local exhaust ventila tion is often neccssarv. it is onlv one wav of controlling dust, anil m certain cases mav not even rep resent the major fealuic of a good dust-suppression sv stem. Local exhaust ventilation is not alwavs successful. It commotilv fails to achieve its end because it has been regarded as the onlv method, instead of being used in conjunction with other methods of dust suppression. One other general observation must be made. Local exhaust ven tilation is emploved to remove dust--not air. This requires some knowledge of the properties of the dust to he removed.`and also nf the manner in which it might he expected tn behave. It also means that the normal method of estimating the requirements of the ventilating svstem. with reference to the volume of air extracted, mav give an inadequate impres sion of the amount of dust it will remove. I hn nrtn It u hit h ttp/n'tifctl atisimil /; tn tin Ikiiiiij] of I mitr*i t i.tl "".tfi l\. i\ fift \cntcii in i mitlt n\t il hint! fhmush t niirtrw ot the /tow#/ s>" ni\ ha the Prrt rnlmn nl f < it/ent s l,ami an IHii\trutn\ii\ arr Itmn imin\ti mi plants /n the I . V I. Part If ,if thn nrtnit. K Ith h /ti#/' mow sjtn itu ali\ uuh haul `than\t t i ntilatiiih nil! appear m an ati\ / w#r Dust and smoke collector hoods behind shakeout* have a capacity of 18,000 cubic feet of air per minute. (Allis-Chalmers Manufacturing Co.) 26 Notional Safety News, februory, 1953 It. In gi-ncr.i.. tin- m n i n.. :::i.ui' tile simplc'1 metimo o! .iii'I 'in*)irx--mo. I*til it I* aixx ax * lie h *1 heeause it prox nil's a < oniplele and filial answer n. ii>. -inolamn Fill ihoriimi e. it axoid' the in-n-silx for eosllx i onlrol appn.im exxhixh max mi up an emiurra"high large .urn-nnl of 'j>.i< e ami make hea> X and ohiIiiiiihii- <i< liiand' oil tile engmeel iiic 'tail i! a rea'onahie 't.ilr of r-tin n-m x i' to he maintained. Down-draft ventilation through grille-topped tables is effective in removing dust generated in the process of sanding and grinding castings. Thin should not he overlooked u lion tc-liug an iii~taliatis.ni. 1 lie fai I dial a unit extract# a sufficient imIuimo of air per minute innv not necessarih indicate dial it is exlrax ling dust sntisf;u torilv. KciTill work implies dial there i- -till ample scope for either fundamental or empirical devel opments. lused on observed pln-iniineiia. ami that careful acrodx nantic studies max sichl f- uilful results. and tlie production engineers of the industrv concerned should ap preciate each other's methods, and die difficulties and limitations in herent in these methods. Elimination of Dust The host wav of dealing with now anted dust is to stop making I'lohaldv tin- eariiesl xxax of dealing with ihi't was to we! it. This max offer one method of dii-i elimination if it proves po-sihle to wet the raw material before pnn ess work commence'. No dii'l will he raised ;n long a- the ma terial remains xxel. M hile water xx ill not net finch divided materials, thex can often hi- wetted if the surface tension of the xxater is hoxered In the ad dition of wetting agents, gix ing what is called "xxet water.'' A further advantage of xxx-t water is that it penetrate' large imb-i-s of material much more quickie. There are. however, other wavs of eliminating dii'l. although the -/ o prrge (t6 I In- oicdioi| nf approach dcin.mil' a much full'-r cooperation di.m i' oflcii c\ ulciit hetneen the ventilating cii;miTr'. the mechaiiii .d i'iuiiutI' u ho dx-'ign the plant, ami the urn m i harg<- of prothicI o a i If I lc f.o I or x i' a new one. dll' .......| MT ,ll loll 'llntlltl till hills' I lie areluli-i 1 ><t ili.it a sintahle Imildmg i an he creeled. In these e111 ...................... the \ .irioU' methods o| ilij'l -oppression can he applied, eilhcr smglx or in ennjunetion w ith each other. It t- important to realize, Ih'Xv ex rr. that sin h a result w ill he aihien-d mi|x when the various < hi -1 lontrol method' are seen in pinper perspective and used m smtahlc eoordmatioii. If ventilat ing eipiipiuenl i- ii-eil. as it often xv 11 i he. the x mil il.il me eng'inccr WTfcll dengned txoodl remove dust from grinding without drawing it pest the worker*! breathing lone. Eihauited air is Tillered before it is recirculated through the workroom (American Air Filter Co.( Notionol 5o/cfy Nvwi, februory, 1953 77 jjust suppression (From mgc 27) possibiiitv of so doing can he de termined onlv bv experts in the process concerned. It demands a wide knowledge of the technical or scientific principles involved in the indu'trv. coupled with great flexihilitv of mind and the faculty of devising new. and perhaps uncon ventional working methods. A good deal of dust may result from dressing or cleaning steel castings after they have been re moved from the mould. This dressing is necessary because some of the moulding material adheres to the casting, and must be removed by pneumatic chisels. If it vvere possible to make cast ings in such a fashion that none of the moulding material adhered to the steel, this dusty cleaning process could be avoided. This opens up a w ide field of investiga tion which the British Steel Founders' Association is vigor ously exploring. This particular work is regarded a? long-term poliev. and in con sequence other methods of elim inating the dust arc being tried in the treatment of castings. One successful development has re sulted from changing the method of cleaning. A flux injected oxyacetylene burner is now being used if' clean the casting in place of the pneumatic chisel. This has not eliminated the cleaning proc ess. but it has offered a method of cleaning which, in certain cases, max eliminate the dust cloud. These examples indicate a wav of dealing with the dust problem which i- iar too often ignored, and emphasize tlie- need for a closeexamination <>f all dutv processes "ith a view to eliminating the du-t Even where there appears to be little chance of immediate suc res;. the ideal should never be forgotten, and the installation of a dust-control svstcin should not be jllowcd to stifle efforts to attain a dust-free process. The second object in dust elim ination is, perhaps, less ambition than the first. This is a change in the process to reduce the amount of dust generated. It is always important to reduce, as far as pos sible, the dust which is generated, because the smaller the residual dust cloud can be made, the easier it becomes to control it. One example of this approach occurs in the efforts that founders are making to reduce the amount of core binder used in moulds. The atmospheric impurity pro duced by the core binder is in the form of fumes, not dust, but the principle remains the same. Once again no general suggestions can be made, because each industrial process must be treated by a spe cialist who understands all the factors involved. This discussion lias been con cerned only with the reduction of the total amount of dust which must be dealt with by control methods. But there may be an other very important factor. Some dusts are dangerous to health, and the total dust cloud may contain a dangerous fraction. In this case, the outstanding reason for elim inating part of the dust lies in the fact that the health risk can be removed if the dangerous fraction of the cloud can be eliminated. A well-known dangerous dust is free silica (SiCEl. h is known that in many industrial processes where free silica dust is likely to lie produced, it will be accom panied by other dusts which may no! be dangerous. Efforts are be ing made, therefore, to eliminate the free silica fraction of the air borne dust cloud. One example of this i= discontinuing the use of silica flour as a parting powder. Other powders arc used which may produce just as much dust, but the dust is innocuous. Control of Dust ^ lien the limit of practicable du=t suppression has been readied o. nie inoiL po.-n.i i- imuious ol eliminating dust at source, there "ill still remain ample, scope for the application of control mctluwfs in cases where it is impossible to prevent the formation of the <1 list cloud. The common method of du^t control is by ventilation, and tinmav be employed as d cxhan-l ventilation or as general ventila tion. or more probable ,w a duplex svstcin using both. It is of sonic practical impor tance to appreciate that local ex haust ventilation and general ven tilation form tv\o complementary parts of on? ventilating system. They should therefore be designed together in new buildings, and when local exhaust ventilation must be fitted into an existing room the whole system should be integrated wherever possible. Local Exhaust Ventilation When the evolution of dust has been prevented as far as possible, the next logical step is to design local exhaust ventilation. This should prevent the dust cloud from spreading into the general atmos phere of the room. * Two advantages accrue when this is done. In the first place, the dust can be removed more effec tively and more cheaply if it can be contained in a small space and exhausted as a concentrated cloud. In the second place, genera) ven tilation can be designed on the as sumption that very small amounts of dust will be present in the general atmosphere. This implies that a relatively small volume of air will have to be handled. Capi tal costs will full, and equally im portant. healing costs w ill he re duced aho. Dust-producing processes should always be housed in building? designed to facilitate ventilation. More emphasis should he laid on tlie simple fact that ventilation is cheaper and better in a properly designed building. Ventilation of a dusty process often means that large volumes of air will be ex tracted from the building. This in turn means that heat loss in the 66 Nalionol Safety Newt, february, 1953 ,, J\in^ l throng cut J WL'/m Wipe ofi those dim. rcas\. \lippcrv tools v>irh .in indusiri.il shop ro"cl Kent them from vour loci] member o( the. INSTITUTE OF INDUSTRIAL LAUNDERERS 1627 K Street, H. W. Washington, D. C. wear a DUPOR No. 40 the Respirator that is U.S.8. of M. Approved lor Type A Dusts More then 40 sq. in. twin filter oreo. Somtofy foce cloth. Soft rubber face mask. Controlled breothing . . . check volves guard against re*breothing stale or . .. exhalation valve exhausts breathed air. Greater visibility ... no blind spots! Does not interfere with goggles or glasses. Sample auti $00 A* H. S. Cover Fog-Proof, Gas-Tight Gogp/et for use w/Vh above respirator. , .. $2.00 pp H. S. COVER, South Bend, Ind. t os tesltd as tiar>- turned in or before being i-uni (it u*c li a Inol prove- dcl'rilixr il i- mum dialclx lagged ami turned m to tin' electrical department I'1: i< pair. Si not* a tool ran In complriclx tested in seven *ocnmk tinadditional xxoik pi.iiv- iif imiiii't on tin' tool nili. \\ eiphmc ir-than six pound*. it max al-o It um'iI a* a portable m*triiincnt 1" le-t took at tbr pom! of opci.i lion. Mu>! i ll-' inral departments liaxr accepted tin- new tr'lin; device because it aid* them in spotting the Inuard. It mean' that after a tool crib attendant ha* found that the equipment giound i* broken or that there is a power ground, llie tool is tlien tagged and sent to the electrical department and give* the electrician a clue as to what to look for rather than to spend time tearing doun the entire equipment. Dust Suppression -- From page 68 signed ventilating sxslcm mrrolv serves to pollute the whole room, rendering conditions worse bv dissipating impurities which would otherwise have polluted onlv the air above their point of origin. Flat roofs offer the worst roiiditions for upward ventilation. The rising air doe> not nnnerge to the point at w Ineli the fan is placed, hut spread* horiroiilallv on meet ing the ceiling. The best wax of dealing with such a stale of affairs i* to insert a false ceiling. The false ceiling is perforated all oxer it* surface and the extraclion fan* are in*tallei! in the ceil ing ahoxe it. There is. therefore, an even extraction rale oxer the xxhole area of the ceiling anil the rising air will he extracted at the point it meets the reiling. The method is more efficient if hang ing partitions are placed over areas where large volumes of fumes arc generated. Downward Ventilation Rooms which do not contain hot processes may he ventilated downward, from roof to floor. This method is not so common in Crilish industry, but there seems Notional Safety News, febrvary, 1953 minimum. \dijuale facililics. fr <(11 f maintenance and re|,,m work are n\ailuhle tu a group .min' "f ill'' most Inglili skilled I,1 h.iim - i 'i i J--rmbh*d in one I.a-i. I>ni n<il least, in its contri1 ailnm to a "nod safety record. Iia- been tin- program irislituted J. \ 1 he inntrnclur to have the mil kmen utilize their leisure hours < mi-trui lively. Available for the u-e of all concerned arc free iiiioii-. a \rrv complete library, a lui|i)i\ slinp. a recreation room, a mu-ir room, the local radio sta tion which broadcasts 2-1 hours a da\. ami the local daili paper. <)nl\ through the active com bined efforts of the lop manage ment of The Corps of Engineers, tin i outrar lot. and the insurance omipjin has it been possible, timlet such rigorous conditions, to attain a safetv record which is fur linies as good as the average i.oii-ti ut lion, of this t\pe. in the Continental L ilited Mates. Check II -- ! 1 tint price J > and engineered, being made of be.i\\ L'a.uee sheet metal, fullv j 1' .il 1 nleil. protected In a fused in ml. operated at a safe voltage .I b Milt-, ami contains heavv dutv "I'l.iil- 1 ela \ - and good wiring 1:1 -111 e. I ut iher. the u-e of the instru ment i- not confined to power ii.in.l tool-. It nu\ be used to test i \11 11 ~n. 11 i.ird-, extension lights. ' iei tin fan-, lending machines, oede-tal grmdei-. oliirc maelimes. I' -k lamp-, i I *-11 r scrubbing and poli-luna mat lime-, and. in fact. 1. n \ -MiL'ie-plia-i' eleitrii.ll device w 11 n 11 11 1 en e- it- pi hi er from a n . i'oI .a ir. 1111 iilenlalli. 1 lie III-iiti!i" iu i ''iit.iin-- receptacles that will ai I ' annioilale am' tvpc of 'lriiiii.il i.ip. All that is neccs-m' 1- I" operate the three push button- in proper sequence, testing all 1 in inis and watching fur the -afr 1 green light' and unsale 'red light 1 1 01 id it ion-. Location for I'm* I he most logical location for u-e ot this equipment is in the tool crib and the test can be performed In a tool crib attendant. Tools are National Safety Newt, February, 1953 No. S04-S Wear a Reece "Strong Toe." Comfortable leather uppers. High, roomy steel toe pro tector, heat-resistant wooden sole. Have comfort-safe feet at work in oil refineries, foundries, steel mills, factories. The Reece "Hot Foot" sandals. Protect your feet in furnace and coke oven rooms. Straps on over your own shoes. Heat resistant woeoen soie, strong gal vanized iron counter, flexible hinae toe. Cannot slip. BE SAFE THE REECE WAY WITH A REECE "HOI FOOT" SANDAU REECE WOODEN'SOLE grSHOECO^;^.. Dept. NSN 2 Columbus. Nebraska The complete line of aluminum maintenance and con struction equipment . . . built with Louisville patented rung assembly . . . reinforcing and locking the rung to the side roil. In plant after plant Louisville equipment is writing new chapters in SAFETY -- DURABILITY - ECONOMY. CHECK WITH YOUR INDUSTRIAL SUPPLIER-or WRITE 107 I. be a grow inf triidriicv. to use it in .wwerlcm Ilf advantage* arc pbvinu- and i! extract* <lu-l and fume? without lifting them ]ia*l breathing level in the pmee**. The general method i- to blow in suitnhlv healed air at r>>n{ |e\cl. The ini (inline air ntav be blown through di-tributnr* nr through a IH i fnraled false mof. In the latter method a >cemd. perforated, ceiling i> placed lielow the ceiling and air i- introduced under pressure between the ceiling and the false ceiling, so that it , enters the room through the per- fixations in the false ceiling. The air i# extracted below breathing In el. and if the processes in the loom are provided witli local ex- ; haust ventilation this may serve to extract all or part of the air. i The whole *v*tem needs careful balancing. Supply of Outside Air | All the air extracted from a building must be replaced by fresh air from outside, and this i incoming air should be under con- ; trol. This is because the uncoil- ; trolled ingress of air may short i iK iiit the general ventilation sys- ; inn and give rise to drafts. In | hot proccsc thev mav he strong i noun'll to vitiate the whole ven- I ila l mg sv stem. ] 1 lie incoming air should lie ic.ui. ami great care should lie i.ilo-n 1.. avoid contaminating this nr before it inter' the building. \ i r intake:- should he arranged so liiat lliev lunnot dravv du-lv air f i mu outlet (lint' vi hull are dis- barging from nthei parl of the hinliling or from particular proc- 1 hie im llmil of picvciilinL' this i- l" i hat c out let dui I- high up ail the building-. I Ik-sc outlet mu l- should be designed to dis barge at high vclncitv. so that the u-eil air will be carried avvav fi "in the far ton . Outlet duels should never be filled with covers. These covers le-trut the discharge vciocitv and b.dlle the air stream, so that the -pent air is turned down over the bn ton roof, instead of being de luded high up into the outside atmosphere. Ideally, incoming air should be delivered to the place at which it ' Notionof Safety News, February, fPS3 o SNAKE BITE KIT t when the snoke strikes...you have 10 minutes! ... this requires dependable, controlled suction to prevenr the poison from spreading. In the New Improved Saunders* Kit, all components ate packed for quick, easy use. Only the Saunders* pump catties a per formance gvjrantrr. Easy to operate by the victim alone if necessary. FITS ALL STANDARD UNIT TYPE FIRST AID KITS. When advisable can be carried on the person in belt pouch. Write fot details. Patented 'V* Accepted lor advertising in Publication* of lb* American Medical Association. Medical Supply Company "It poy% to buy--from Medicot Sitppfy" ROCKFORD, ILLINOIS IN CANADA, IT'S SAFETY SUPPLY CO. S<W 10-WAY l X I of better eye protection f| f | at lower cost... EYEGARBS THE GOGGLES WITH THE VENTILATION BEST THING NEXT TO YOUR EYES When you ask fot EYEGARDS you assure your workers Ihe very finest rn eye protection ond comfort -- and you do if with lubitontiol saving*. EYEGARD goggles have buill*in comfort because the super-light plostic "form-fits" the foce hove greater protection because goggles ore impoct resisting . . . hove extra venhlotion through three large venti ot side of cup ond seven additional vents oround the lenses Cool ond fog-free. Prices will surprise you . . . get the information todoy Write for tree colaiog. Illustrated it th# No 335 Wld,*s Cwertpfc Goggles. A wide range ef other types are available at savings. 7 Vents Around loch Lem AMERICAN INDUSTRIAL SAFETY EQUIPMENT COMPANY 3501 LAKESIDE AVENUE CLEVELAND 14, OHIO DIVISION Of THE U*DfTT OXTGtN COMPANY, C/.l.d. Oki. I 109 sft)iEC>ps;S|jDitiBr t IDENTIFY YOUR CONTAINERS WITH BRADY CONTAINER MARKERS Protect your people and your property. Comply with your state safety tcgulations. Mark all your containers, drums, carboys, bottles, barrels, etc., con* taining hazardous chemicals and solvents with safety approved Brady Container Markers. Mounted on handy Dispenser Cards -- quick to apply -- quick to identify. Bold black letters on caution yellow back ground provide instant visibility. Strong and durable, made of sturdy cotton cloth with Silicone Plastic coating. Self-adhesive, stick to any dean, dry surface. Send for FREE samples today. ----------rrJ Wt imiu HFiWt l>llWl 4545 4 imO* MiNuricruioi oi stu sneimc noeven 11 LL3W.H. 1 I i COMPANY Hlfl Itl COM 780 W. GCENDAli AVENUE MICWAUKfl U. WIS. ?A OJU IPMI N T0 Jt VA tl ^NDII ST* I .l IIPCO MandM RAIL CLAMPSl ^ For car stops, on loading platforms, temporary sidings,^ 0 cars on grades, and traveling cranes . . . Used and rccom- 0 0 mended hv leading Steel Companies, Manufacturing Plants, % 0 Mines, Crain Eicsators, Cement Plants and Quarries. l iPtl IWRITE FOR BULLETIN NO. 44 'Sa^eh] Equipment fmaiL^nduAbuet. inousTRini products coniranv J 2850 N. FOURTH STREET PHILADELPHIA 33. PA. t to i* nt ( (ire!, i>i' .11:-1 it it i- intii<Si*<-<V1 at M'lttr 111~.i:i,, it,mu tinpoint It "ill mix "III: tumc- troll: other source- a- it p.i--i - liuough the building. It dl. in .tin o.Im . lose it- xrlorilx if it li.t- to travel long distances. If xcloritx can i>e inaintained. a smaller xoimne ''ill In' needed. On tin other liantl. drafts must be avoided so that incoming air should tml be <!>i.xored in the form of a ji t. "hicli might impinge on the oct upanlof tin* room. \T hen tin- air has lost its velocity in transit il max still be controlled bx reason of temperature. In plenum sx stems. il ha- hern found in Sweden that the incom ing air can be introduced al a loxvcr temperature than that of the air in the room. A- the air :blown in at a bright of about 7 feci, this rool air fall- to the floor. The angle at which il falls can be controlled bx regulating the inlet temperature ami the xvhole system gives a sxx roping cfTcrl as the rool fresh air falls to the floor before warming up and rising to the roof extractors. Tins kind of control offers real possibilities, although further information is -till needetl to obtain the eorreel air moxement bx judicious use id xelocilv and temperature. One final point might be noticed in general xenlilalion technique. Certain industries produce large xolumes of dust and fume- al particular stage- in the prorc*s. In these cases it max represent a considerable saxine tn beating costs if the general xenlilalion s\ -- lent is designed so that the ex traction x nlumc can be increa-cd to meet the -hort period- at which tlie maximum ilusl or fume pro. duct ion oc curs. Tact is gixing a per.-on a shot in the arm "itlnmi letting him feel the needle. "Smilhers.'' said the boss to a meek employee. `1 understand you vr been going over inv head. ' "Not that 1 knoxv of. sir." re plied the employee. "Well, isn't it true that you've been praying for a raise?" Notional Sofety Newt, February, 1953 - / f Grinding booths equipped with iocel downdraft exhaust. Fact pro* teetion is also provided. PART II Practical Aspects of Dust Suppression By W. B. LAU RIE M. S<-.. K.K.M.S.. A l.M. T OCAL exhaust ventilation sys- sv>tcis normally consist o( a hnod. duct and a dust collector. Theoretical considerations arc u*ualh concerned with hood Hesnips, duct designs. and fan char acterisin'?. But the major problem 15 to pet the dust into the dint. Once the dusty air is safely through the hnod and into the duet it can ensilv !>,- conveyed to a dust collector. It is quite another Till' article. Part II of one which icpcared originally in the British Journal oI Industrial Safety. i? pre'tilted in condensed form through courtesy of the Royal Society (or the Pretention of Accident?. London. Part I. which appeared in the February is 'lie. dealt with the more general aspecis of dust suppression. T11 n=i rations are from industrial plants in the L. S. A. matter to capture the dust cloud. Far too little is known about the mode of dust formation, and propagation from its point of origin. Tl ic aerodynamics at this end of the local exhaust system have unfortunately received noth ing like the attention given to the somewhat easier problems of dust conveying and theoretical fan de sign. The first necessity in any looal exhaust ventilation system is to capture and contain the dust. It is probably true that this has been achieved only where it has proved possible to enclose completely the point of origin of the dust. It is certainly true to say that total enclosure represents the most effi cient and the cheapest method. Here again there is an urgent need for. better cooperation betvyecn process men, machine de signers and ventilating engineers. Every dust-producing process should be carcfullv studied with a view to devising working methods which allow total enclosure. This should be done before open hoods are considered. In many cases total enclosure has not yet been achieved, but the point at which the dust is generated should still be enclosed so far as this is prac ticable, and the partial enclosure should be designed so that the. volume of air inside it is as small as possible. This implies a close fitting hood with a small opening. Where it can be arranged such a design has advantages over the big 31 Notionol 5ofery Newt. Moy, )?53  -. * * ' ' V i- - ::;: gi- ..pen fume cupboard type of cn(I os u re which lias a large area across which air has to he ex tracted. These large open faces need large \olunies of extraction air and give a correspondingly large heat loss. Exen the high air xolumes U'cd provide onlv low local t-vhiusrVcnltlation need onlv be applied to a small area. If the ladle is moxed along the eonxeyor. fumes are generated along its full length so that the local exhaust xenlilation must be applied oxer a much bigger area. When large numbers of ma velocities oxer the face of the opening, and may not gix e efficient control of the dust. chines or processes operating in a single room have to be fitted with local exhaust ventilation, it is al More thought should be devoted most certain that there will be a lo the use of high velocity air high rate of air extraction from curtains which operate on small the room. This involves a corre air volumes. These xxould result spondingly high heat loss. in much smaller heat losses, and Efforts are being made to sup there is reason to beliexc that they ply cold air to the local exhaust provide more efficient dust con ventilation system. If this could trol. High velocity air curtains be done, unheated air from out may be obtained from suction side would feed the local exhaust fans, or they may be provided by units and be extracted and re jets. The jet.may. of course, dis turned to outside atmosphere sipate dust, if a dusty object is xvithout being heated, and xvithout loxxered into it. but it can be em affecting the heat balance in the ployed in conjunction xxith an room. Much more thought needs exhaust hood, xxhen the positive, to be given to this idea, xxhich high-velocity, low-volume air cur xxould offer great savings in fuel tain it gives is used to direct the costs. dust into the exhaust hood. Local exhaust ventilation is A careful study of the process sometimes applied to enclosures of generating the dust max suggest the funic cupboard type in small adaptations xxhich w ill facilitate rooms. The reason for the small application of local exhaust ven room is that the dusty process is tilation. A good example appears thereby separated from other m the modern mechanized foundry xxork. In these cases great care xi here moulds are placed on a must be taken xxith the supply of convex or belt. Molten metal is air from outside. poured into each mould from a ladle xxhich is supported on a block and tackle running on an oxerbead rail. The system can be operated in txxo xxays. Either the moulds can nioxe past the ladle xxliich remains stationary, or the ladle can be moxed along the convex nr belt from mould to mould. Fumes are exolxcd as the metal is poured into the mould and local exhaust xen- Illation is applied lo control them. If the ladle remains stationarx. and the moulds are brought to it. : the area of the pouring operation is limited to this one position, so If the faii oil the fmiie'ciiphoard i> large, the rate of air extraction through ihc bond max be so high that a negatixe pressure is set un in a small room. In consequence, the opening of a door max' alloxx sucli a rush of air into the room that tine direction of air fioxx across the hood face is rexersed. and the dust bloxxn all oxer the room bx the erratic eddv currents xxhich result. This effect is not so appar ent in large rooms. Recent Developments Much exploralorx- and dexclop- ment work has been undertaken recently in one industry and the results have been published. In 1948 a rapid dust estimation technique xxas dexised to permit rough comparisons between condi tions in different foundries and to facilitate collection of dust sam ples. This method shows the resid ual dust concentration in the air and permits an estimate of the efficiency of various dust-suppres sion measures. In half a dozen buildings se lected at random, it xxas nuticed that the dust concentration in the roof exceeded that at the breathing level, which suggests that general ventilation might be defective. It xvas also noticed that sxxing- --To page 142 Thix man is filing magnesium cast ings in a booth aquipped with eihaust vantiiation. E- Notional Safety Newt, Moy, 1953 29 POISON IVY O I NT ME NT proved jn the field with eight years' case history Give your held workers tins proved protection against poison ivy, oak, and sumac. Use < Jiretentire or cure. Packaged by MSco under tlie Unit System to lit all standard unit type lirst aid kits. Accepted today by numerous held operative industries as a "must" in all lirst aid kits to combat the ,2. poisonous plant hazard. Write for complete details. Medical Supply Company "/l fMiyi i buy -- fronti VrifiVn/ ROCKFORD, ILLINOIS IN CANADA, IT'S SAFfTY SUPPLY CO. ", make <flovestet BEFORE leather RUBBER OR COTTON THIS IS WHAT "WASH* RITE" DOES... Irvow oil yovt ditty, worn leother. rubber or conon gloves in our steel drum $hp to us We correctly cleon. sienWze. COMPLETELY1 REPAIR, sort reshape, potr ond ship them bock to you os serv. ceoble os new. Depending upon the gloves ond their usage, gioves ore oemg re-cloimed by us 3 to 5 times. We speciolize only n laooratory controlled r*cloimmg of rubber, leother ond cotton gloves, oprons ond clothing. Wrrte for httroUjrt. 10 Ytors of Proven Service YOUR GOODS FULLY INSURED ... WORK GUARANTEED i 2*dh i , size jui>in I 'Li in i i nc>. Steel' ( nMi" -!iit. iu,l I'. iw (Til ` steel towel - `r 11..i. ~ .ire Ire.iuenl tv Used to prole! inch V'dl.l'.1' electrical fciiiipincnt. in l.n-. .d most all ver\ Iml'Ii voltage Iran-- mission |mi' have in' nr ecrgrounded < nmlui inr- hn aied ahov,the phase wire? i winch urn "en trails carried mi suspension m sulators i In pmtcc l the \'lem against a -11 *>ki-. The same m stem is sometime1' u-e<l fur nil lank' nr other structure?. Wire feme?. particnlarlv when mounted on wnud post-. mas earrv a lightning stioke a lone dis tance and trec|uenll\ kill cattle grazing along such a fence line. W ire fenc ing should he grounded at intervals of about ISO feet to present the transmission of this hazard to persons or animals at a distance from the point orig inally struck. With present engineering knowl edge. almost anv structure can he made rcasonahls safe from light ning damage. Steel-frame build ings are inherentls yioleetrd 'f the foundations are rcasonahls deep, but occasional)s damage i done to brick, stone, or terra cot ta copings when lightning makes its was through such material to the steel frame henealh it. This can he taken care of hs a flat strip or small angle of metal placed along the outer edge of the iipsours and enmieeled at inters al? to the hilihlins steel. The basic principle' of li"hlning protect bin should he under stood bs even 'afets eug'iieer since it is both an occupational and ail nIT-thc-jnh hazard. Dust Suppression --From j>nt:c 20 frame grinders without local ev haust ventilation gave dust con centrations similar to those at swing frames fitted with remote hoods and extraction fans. This suggested that remote hoods were inadequate. An average of samples taken at pedestal grinders was then assessed because these machines are normallv fitted with local exhaust ven tilation through the wheel guard. The average dust concentration obtained was compared with that Nolionol Softly New, Moy, I?53 uliitli hrr liKMtctf within fix feet f .i ilun ' tiiuiuclor arr penrrallx lii'il i 111 I In- lightning system In ax mil i ill- flashes to Mich grounded nwlallir masses. Tin* i m 11 i | <i(' ground system also (urhi-Iii'- a morr dirorl path to ground (or a flash striking al tlir -tilt- of a building. The grounding is generally aci omplishrd hx clamping each down oonduclor l<> a pipe or rod which has been driven deep enough to u-acb a ln\er of permanently moist ground. In most locations, this will be al a depth of six to eight feet. Where the soil is very dry. or where there is rock within two or three feet of the surface, a ground loop of heavy stranded topper or galvanized wire is placed in a trench 15 to 18 inches deep and all down conductors attached to it. >uch loops are frequently used a- part of the protective svstem for old and valuable trees. All of the old trees at Ml. Vernon fsomc of them |>1 nnled bv George TS ashiiiuloni are so protected. In such rases, the dow n conductors are led radially outward in shallow I rent he- to the loop which is of "rent eunuch diameter to he out-ir!e of tlie root aica. If rod* were drnen i lose to the trunk the eurrent from a stroke might serimpdx ilamaL'i' the roots. \ till, "rounded metallic ohjeel will "i\r almost perfect protection I" .111\ ohiret located uilh'n a 1.5 di'erre .mule of its ton. and am ohteit within a nine nr'k'n" a all rec ancle with tlm eroitnd re- ii'IM's < oti-ulrr.'ililc iirolri|ion. fix tt'inc a sitts of "rounded yrrl'ri! -Ice! \rr\ stood iisolert'on in o he -mired for structures within a lone Minkins a 15 degree ancle with the ground. If the lops of such poles are connected with he.-u \ -stranded eahle the \nlumr (irolreleil hecomes ''lent shaped.' >uch sx stems are widely used in industry, particularly for ex- plnsiw- ioailiug units and similar plants where it i- desired to keep the discharge well nxvav from the structure hut arc seldom used for residence' herau-e of llteir more or lc.~- ungainly appearance. How- exer. ornamental bronze flag pole- coohl he designed and located so ps to afford protection to moderate Notional Solely N.wi, Moy. I9S3 IN ANY SIZE SPACE Available in wniti to ttot 4 to 24 people, For Recreation Rooms Factory Work Tables "CHF" Sectional Tablet may bo pufchoted in varying lengrh* !o meet your exact re* quiremenfi. Seats swing completely under table out of tkt way to give you full oitfe space. Your choice of seots . . . with or without bocks . . . cost iron frame construction in a variety of colors. "CHF" Sectionol tables ore standard equipment for schools, factories, dubs, churches ond ell types of institutions. WHITE FOR ILLUSTRATED CATALOG AND MICE LiSTf THE CHICAGO HARDWARE FOUNDRY CO. "Dependable Since T897" 1053 COMMONWEALTH AVE. NORTH CHICAGO. ILLINOIS, wear Cover's FOG-PROOF x/' GOGGLES Famous "Nod & Shake" Type Used by thousands, for years, to protect eyes against gases, dusts, fumes, smoke, paint spray. Con be worn with any make respirator. Frames ore of soft, pliable rubber that give air-tight fit on any shape face. A few drops of water placed in patented groove keeps fog from forming on inside of single lenses. An easy nod and shake of the head keeps lenses dear indefinitely. Scuaftle *2Q0, &e*tt H. S. COVER, South Bend, Ind. 141 given l.v portable grinders. pucumat iff; h'rhhi*l: ianri'~w i Ti'g^jfr a me gVito Irr-. a 1 i< > f w Jiirl i: wv ru * '] icrltl-iug'vv illuuil ixlum-l. Il w;i- auliri-" j>al<<l I lint iIhtc unulil l' a i oniilcrablc, difference between these tun averages. lint this, did not. prove tn In.* 11it* case. This result inav lie due In the fact that the exhaust svslems arc Hrauing aver age dustv air from all over the unikroom. or il may indicate that the local exhaust ventilation wa not so good as cx)iecled. While this exploratory work uas proceeding, the engineers engaged in neu designs for dust control apparatus asked for a method by uhich the (lust movements in the air could he seen. They did not particular^ uant the method to he quantitative, because dust concen trations could already he deter mined when necessary. They did. however, want to see the locus of the moving dust clouds, particu lar when local exhaust ventila tion uas applied. This demand was met by the development of means In which the dust could be seen and photo graphed with a cine camera. The lieu tcclmnpie has been used for empirical development work, and in .in attempt to determine the n.iiiir.il flow of du-t from its point of origin, mi (crtain iiM.iniT*. The ohji-i I u.i- lo Use the dust to ohrne tin .icrodv namies of the svstern. I irsl re-ulu have shown that an . 111 r .t-1 v i- wheel running without local oxli.iu-t v enl il.il 1011 and in l.ilmratorv < miilil ions, inav give a du-t i loud v\ Inch appears to circu late in a vortex above and behind tie- wliril u-rlf. It was seen that tin' line du-t from a pneumatic i hi-rl might How up iIn- arm of the operator, and was not projected along tin- path of tin- metal (hip-. t Mi-itv at loie were al-o made on floor -land guilders fitted with lo cal exhaust ventilation, when il wa- noticed that the fan effect of the wheel il-clf might he so great that the dust was projected from the front of the guard, and not cxtrai ted In the fail. In one in-lance, two dust -tream- were seen on a pedestal grinder lilted with extraction ven tilation. One stream was obviouslv caused In the fan effect of the NaUonal Safety News, May, 1953 Wear a Reece "Strong Toe." Comfortable leather uppers. High, roomy steel toe pro tector, heat-resistant wooden sole. Have comfort-safe feet at work in oii refineries, foundries, steel mills, factories. The Reece "Hot Foot" sandals. F-oteci your reet in vu'nece and coke oven rooms. Straos on ever your own shoes. Heat resistant wooden sole, strono aalvanized iron counter, flexible hinge toe. Sizes--SmallMedium--Large WRITE FOR CATALOG REECE WOODEN SOLE vHsHOE^Cfe Dept. MSN 5 Columbus, Nebraska E-X-P-A-N-D-E-D COTTON SWEATBAN DS ONLY 2'/s$ Sa inexpensive, they con be usedandthrawnowoy... So strong, they can be rinsed and used repeatedly! FEATHER-UGHT-You feel only soft cool, comfort! * E-X-P-A-N-D-E-D COTTON --Cottonbacked gauze expended to 8 times nor mal thickness! FOUR-LAYER FOLD --Extra absorbent (opacity I NO METAL -- Only pure cotton ond cot ton-covered elastic. No rusting, chafing,no discomfort. Here's the answer to perspiration... supersoft, super-absorbent E-X-P-A-N-D-E-D COTTON SWEATBANDS. Real com fort for those hot-spot jobs ... a better band at a lower price. Perfectly designed. No metal parts to rust or chafe, cotton-covered elastic holds band firmly but you can't even feel it. Get E-X-P-A-N-D-E-D COTTONSWEATBANDS from your regular dealer in safety or first aid supplies. Write us jor jree sample today. GENERAL BANDAGES, INC., Chicago 5 gV jMakers of GAUZTEX--ThejaandageJthafsticks toyttself.dr. 143 a new high Safet Doylon Safety ladders, with c> "safely level working platform, rr.c jobs "ground safe". Check the features that moke Dayton your is- -we gh 6" .uy: 1. lail-guordfd "Safety level" plot12. lochs in place automatically, 3. ftubbtr safety shots, 4. light wtighv--great strength. 5. Economically priced. 6. Complete siie range 3' to 16' in height (to platform). )MAIL TODAY safety tedder co. Doyten Sofety Ladder C*.. Dept. 0 2339 Gilbert A**., Cincinnati, O. Gentlemen: Fleece tend tree (Mere* Ivre, prices, etc. en yavr Made! A Sofety Ladder. Naim Company. Address__ c..r___ -State. 2339 Gilbert Ave., Cincinnati, Ohio In Canada--Saftty Supply Co.--Toronto presents a sturdy truck to carry the KENT SUCTION CLEANER and extra dirt receptacle! Large Capacity for DIRT and LIQUIDS! KENT Suction Cleaner and 27-gallon tank tor extra capacity are installed on truck in a jiffy--and as easily removed -- without tools of any kind' Auto matic shut-off valve in cleaner operates when BOTH tanks arc full of liquid ... no water can enter fans or motor. Ten sion spring holds adjust able handle in position shown when not in use. THE KENT SUCTION CLEANER for wet and dry pick -up is quickly avail able for separate use when less dirt or Liquid capacity is required . . . and suction unit can be used as a blower! The priceless ingredient of quality is built in every KENT Machine--including the famous KENT Floor Machines. All are built to last.' 144 wlierl. because jui-i above llir wlwd tli'- dust Mrcam rut- limp out Iir guard tou.iri! tiir operator. The other du-t stream was muv mg into the cuard ii'inn diatclv ah"\r the firsl one. 1 tu second stream wa- due to the du-I extraction -isiem fitted 1" the wheel, but it did not appear t< contain as much dn~l as the out going stream. The implication i- that a local exhaust system might extract air but fail to control duct. Swedish engineers ba\c been successful in a \ oiding use of hoods over small ingh-frequenev furnaces. because of the strong upward convection currents over a furnace it has been normal in tin- past to fit a hood and fan over the top to collect the rising fumes. These hoods arc often a nuisance, especially if cranes are necessary. The high-frequency furnace is of small diameter, and so it was found possible to avoid the . ood by applying a very high ve ily air curtain immediately ovc- the furnace. In this instance the ^curtan is not a jet, as used ov the dress ug- bench, but is prov -ed by suction fans. The e.xhaus' optionees are below floor level i offer ik re striction to the pn '?# v\m- amount of air h;ii.. ed ha reduced so that the tval loss ;. the building is smaller and ti fumes have been controlled. Conveyor belts dealing with fuming moulds arc often passed through an exhausted tunnel, which mav he of considerable length. Large volumes of air mav lie needed to exhaust those tunnels, so efforts have been made in Swe den to supply some of this air direct from outside in order to reduce heat loss in the room. These efforts have been so success ful that in certain instances more than half the ventilating air is never heated. Conelusion It is impossible, in a general survey, to discuss in detail any single feature of the diverse and complicated devices used to sup press dust. If dust suppression is rightly approached, it is not easy to discuss more than one industry, although it is obvious that if dust were completely controlled in one Nelioiml Softty Ntwi, Mey, 1953 > industry. a^rpperuridcrMaiulipg_, ,, j;i Hp,';ychrr&r w huld iesffer many SggcstWiktto'blhcf iiwlustri'es-. For these rr.vsim-i jomo features of dust suppression !ia\c been ob served with a view touggesti.np im practical aspects essential tn ul timate success. Examination -of many plants leads to tlie conclusion that the j first neressilv is a more liberal aj>- proach to the whole matter. It is . essential that all available methods -j should be examined, and that the final scheme should represent an j integration of every available re- | source. I In particular, a practical out- j look demands that local exhaust ! ventilation should not be regarded ! as the only way of dust suppres- J siun. It will doubtless have to be applied in many cases, and it will continue to serve over a wide field. Nevertheless, greater efficiency will be obtained, as it is progressively embodied in plans which incorpo rate other ideas. So far as local exhaust ventila tion is concerned, there is still a great need for careful studv of the | aerodvnamic conditions at the en trance to hoods, and the manner in winch the mechanics of dust gen eration influences these conditions. Instances of recent practical work have been given to illustrate the value of empirical development, because it appears, that calcula tions of air llow mav not neerssar11v indicate the cllicicncv of dust ((uitrol. ; Industrial Health -- from pngc 6U it" imt lade in the v\ inter. and area- of dilated capillaries in the -km ~urface. The thing which is "I most ilimeal importance, of 1 "ur-e. i- the tar wart since this i- \er\ < lo'i-lv related to the tar i .nicer. Of these 211 men. 66 had laid one or more tar warts. The earliest wart developed after II months of exposure and the long est exposure before the develop ment of a tar wart was II vears. 1 wentv-six of the men hail had nnlv one wart and the others had bail \arvmg numbers up to 6.1 warts on one individual with 26 vears' exposure. Seventy per cent of the tar National Safety Mews, May, f9S3 4N CORPORATION * A high performance volatile, liquid-phase, non-toxic, non-flammable solvent, a spccuic -- replacement for carbon tetrachloride. A self-emulsifying di-phase safety solvent for cleaning and scouring; non-hurnable, non-toxic . . . docs not tend to de-fat * the skin. A high-performance safety degreaser of the aromatic type -- excellent for metal dry cleaning. For use in continuous-flow liquidphase solvent recirculation degreasing tanks where solvent is automatically reflltercd for reuse. Non-toxic, non-flammable and rel atively odorless -- minimum de-fatnng of the skin. I !L l Ihe worV"r, the p'n' |0,word b.0 ` eP lof Coolers ond mochinev ^ H(J\4eir Y in>ure 0 the '"i,0"^VoP loco*'"* lhe Holvey , slroe9,e * 0( cool wO<e with ,eni.lo"uPpycomplee i topv. ">'e , loY'or l`n* ;0 or v-o-nle^ ^eolefl ond V'*remod*l4- fl'Ce 1"--., t. .->oki" COOLERS US merican' Foundryman Wc<.uni:li.(r.ili'iinn tii> >unl |>m into rK.nl* lompkird p.tiu-ni lot |.irt of pi.mi 'U.mi untune tU.it ml! help IXmmi nn> .1 hjmiic fiiiTB' ;>i.mi When hnuluil. hii.t uiMMlrn tinin mil In uvil (o imuliiii mimI ninltl limit mo hi util fonii tuii.m of Lhiij vuOL" steam luiinm nun ii>m mm oni ul M\rul null M (I In I lif t >hn* \ .lllo Eld U u (nip ui si111|>iv |imi lor not .ilnniif mi'll!' I>i.mi in ii 1`nii'iiMMilh Ohio Publications Committee H J Rowe. Chntnnan Aluminum Co of America, Pittsburgh Harry W. Oieicrt Harry W. Dictrrt Co., Detroit C. H. Lorlg. Batiolli* Memorial /nartiufe D. McMillan rnntional Harvester Co.. cnyo H. M. St. John Crane Co.. Chicago F. J. Walls fnternntiOMnl .Yickel Co.. Detroit A.F.S. Headquarters 6iG S. Mu.-higan. Chicago 5 VVni. \V. Maloney Secretary-T reasurer H J Heine Assurant Technical Director American Foundryman 'Vir. \V Maloney. Editor H F. Scoluc. Technical Editor H. J Wheelock. Managing Editor C J Mmogue. Production W N. Davis. Safety 4 Hymene 4 Air Pollution Editor r E Fostei. Transactions Editor Teii > Kocilei Advertising Mnmioe* Advertising Representatives Midm cstcr.n--Dwight Early 4: Sons 00 .\. EaSullc Sc., Chicago ."Entml 6-2U4 -cntral--R E. Cleary. Commercial & Savings Bank Bldg., Berea, Dhu Herea 4-7719 Eastern--Robert B. Weston 6 E. J9th St.. .Xew York lurrnv Hilt 5-9450 Volume 24 October 1953 Xumber t Published by American Poundrymen's Society In This Issue . . . . Editorial ........................................................................ ** Side-Blow Converter Refractories........................................................ Ralph A. Clark 31 New AFS Headquarters...................................................................................... 40 Evaluating Molding Methods--Part II.......................................................... 42 West Coast's Largest Pump Casing............................................................ 47 AFS By-Laws Revisions.................................................................................... 40 Incentive System and the Foreman............................................................. 50 John Taylor 1954 AFS Convention......................................................................................... 52 Dust and Ventilation Control........................................................................... 54- Fire in the Foundry............................................................................................. Cl Basic Foundry Cost System............................................................................. 62 Earl Paltenghi AFS Nominating Committee Meets ............................................................. 67 Fracture Test for Red Brass............................................................................. 68 Determination of Tungsten in Titanium.................................................... 72 Maurice Codell Northwest, Purdue and New England Regionals................................. 76 Departments . . . . Here's How............................ Talk of the Industry............... Products and Processes ....... Free Foundry Information .. . Foundrymen in the News .... Future Meetings and Exhibits The Foundry Quizmaster .... Chapter News.......................... News of Technical Committees Foundry Trade News ............. Advertisers Index................... Classified Advertising............. a 10 18 22 51 75 78 82 85 114 115 I'uMishcJ tinmh. t>* (Ih Aniritc^n !ouiuirynicn Soviet). Inc., oil* S MicIiii.mii \vc.. t-hicj^o j. MVjKiiption ptui in ihc L.S.. Canada and Mexico $3.00 per year; elsewhere. $6.00. simile copies 50c. Inietrd i >mul Class Manet. lul* 2-. 1936. under Act o( March 3. .* the I'o't Odvcc. Chicago. October 1953 3 A heavy spr~\ oi \< ,llt preci'iiia'cs dust ,7 r grinding wheel Good sai, M practice interconnect power ior w heel and 11 Mr. supply so w heel canno; b operated without water Foundry Safety Practices This article is condensed from the introduction to the new dust and ventilation control manual, which is being prepared for early publication by the Oust & Ventilation Control Committee of AFS. 1 lit \111c1u.1n loimtli \ mu it s .Soticii. irtngm/mg die 1 nor ill d.i\ cnii'cik ics ol the industry 11 icpi esc ills, c'instituted die lonmiutce nil S.iletv ll\givnv. .mil A11 l'nlItitioii in !scpicmbci 1 lie tniiimuiec was 1 lunged with the |()h nl formulating .1 code of good piat tues 111 these time lel.iied fields The ohjettise is in 111.Ac the louiitliv ;i heller plate m iuiiL; to en.ihlc the industry to be heller neigltbois in the tointuuuii\. The .Sot iet\ rciugni/ctl licit the industn Icis .1 mm .d nhliy.it it in to pres cm tit 1 iilents and to el imin.ne 1 u t uji.ition.il disease: lien it must tin 11s pan in ton- nulling air pollution h\ taking stith steps as ate piatrtical attending to fin.mri.il means. 1 01 las. management know s that 11 must pi o\ itle sale ami healthful winking conditions it u is to sue teed: and that it is betict lor an industn to establish its own standauls of safe practices than 10 wait and 54 American Fourrdrymon have them imposed b\ niheis who ate not as familiar null its spec ilit piohlenis. Atlheiente to a pioytam designed to eliminate atiitlenis anti 011 iip.uional tlisease is not merely a ties 11 a hie 11111 hut is just good In is mess. Whether one is sell instii etl 01 not. at t itlents and 011 up.uional disease aie c\pcnsi\c in medital. 1 ompensaiion. and produc tion insts. These, at times, ate hidden, but careful anahsis will show them to he stirpi isinglv high. rurthcrmorc. it is in the interest ol the Foundry Industry lo improve working conditions in ordet to olnain a tompciitive advantage. The hetter work men will not he amatied to the Intimity, or if dies ate. thes will not star unless ihcic is some assttraiue ol Irccdom lvoin mpir\ and sickness. Mil'll employ ment inrn-oxer is tosily. There is a great investment in snpetvisors and skilled workmen anti it is good business to keep them on the joh. If the money wcu ay.ulahlc every machine anti piece ol equipment in the foundry could be re placed but not so, good production people. Law suits for injury and damage t.iuscd by air pol- | (| tl,jglu lie more expensive than control. l'ol!"l'11i, sin I' .i' berv llijuy.. l(;.ul.; !.du>tji)ioi it'.. tton |,jn-m<I in 111mr'liJiiid-iVo))(i-ili'm' (-in <|iiiu- ' iPi i.ni-c ncighboi liiiml damage .mil nni pci'octal "j,, h.isiiii "l ilie (otc-going. liit- umk ol ihc (mu ha> lmi'i' dure ted tow.ncl* lorniulaling till' l( ,,i | ih1'cm ion .ind council. Tt.c members thercol 31 "attr u |,,i.|ilt who ate cither winking in the loumirv I,,,ii' oi arcilosclv ii'vk i;itt(l with il as eipiipmctu a' the (,1,1k i' C .onsvtptentlv they me lamiltai with ilic Good z&je. , ' (jin |)iul)lcni' ol producing castings. connect, ' nc? Ha;er ! cannot b* I he tec ommcnchd Rood ]>v;iciice-, developed here 1...,((! mi present d:i' knowledge ol ttic print ij>let> ,,lti\. h'gienc. mill :iiv pollution, li is subject to ,u! water. 1.,n ii lien ;ind if new d:ii:i or conditions indicate. I |h u, uiniiifiuLaions ol this code must he practical i .lie io Ik- adopted and effective if they are to ,,l Ik-iu-Iii. Thcie are many potential hazards to . ,1,1, jn Iniiiidrr practice t>ut only the more common j pi iniip.il ones are treated here. \[,,,i foundries are not equipped to make environ- iicni-d measurenieius. Imt tlircshold limits enable ,|lf munch v man to ascertain the relative loxiciiv ol 1 die pi nu ip.d rontaminanis in his plant. For instance. ,, Kill be seen later that (id times as ninth iron oxide , ni lie lolciated in the atmosphere as lead. Medical Protection In icgu id io tlie medical phase of worker protection, ..nod ;>i.ic ticc suggests as minimum: II i I'rr-plac ement phvsjcal examinaiion and i host Ni,n l lu-. enahles mmia^ctncm to pi.tie an employ ment applii.mt on a job suitable lor him without i ml.mgi't ing, lellow emplmees. Foi example, a man u 111 h 11 depth pineption liaidb cpiulifcs as a (lane -,iid a nn . I1 - lmiu.il plnsicd ex.nninalion and < best x-ra\. llu, pi ai i k c ki-eps I lie ( oil i pain s | >ln su i.m iiilomicd - I. n 111 i i a r .a ilic state ol a man's health so tli.it iik ipienl disease , m In. misled calls; let lassilu at ion ol einplm mem i .m lx made, oi otlici ailion i.m be taken as militated in die exam mat ion. I Im leiiomuls in the benefit ol imili llu einploiet and emplosee. 1 ,\ilei|u.ile lit'l aid l.udiues in else ol inpuv inmate -a illness 1 he benefits ol fist aid should be obvious. ieh n The lollonmg sei lions mdii.ue when icuicdi.il 'hi i me i) mcasi 11 is aie leipnieil and liou ihev cm lie ai ; Incase - i il 111 11 I s 111 (I. <1 odltc- . . .11 i-ful j Casting Industry Health Hazards '-'ll much' Acrolein t.uivlii .ddclivclc) oulei 1 lie ga, hums m lomidrv opei.Uioin limn the ill W Ol k :lici m.d ilei oiiiposition ol i oi e oil. It is veiv poisonous il the' mu lets uliipi.iie M.iiumi; piupcnies h n so mil.unit; 11.1 tit e ( i i llu eves that man cannot lolciatc a i om cmiaiinii mplov j dial vioulil peim.mcmh injtnc him or cnise death. It m.n lie ilassilictl as a nuis.mie gas lathet than a HIS .111(1 t'lsu m.ueiial beemse in praituc ex)iosme ol five - them mnuui-s to one pail pet million p.nts ol an is in- lime 11 Hiia 1 ile | lu- m.iMimmi allow.dile i om enu aiion is re- l!-> put per million parts ol an. Ilvgienn. cuiunil consists prelerahlv ol loetl cxltaust ;r pol- '(nidation or air dilution by genet al veiuilation. Aluminum h - -: V. Sluter and Riddell i| lud H'g 1 n\ 'J11 I I'> <|U;i7i ft.ive teported n immbci ol i.ih-s nl lung chsc-u'C oc i in nng in the mantilaiiuic ol alumin.i .dnuMvcs. \' l.u a> tbc casting and gt Milling ol aliimmmn. .dims is tonicrncd. die metal mat be iniisuieicd non [Xlisollolls. I lie principal il.mgci is liom foes and dust e\ plosions in diist (olleitmg svstems. Antimony Cases ol industrial poisoning (loin amimonv me rare. It is difficult to obtain n (le.u pu tme ol svnteiomulologv and in founding opci.ilions u probable is an unimportant contaminant. Men exposed to ami monv fumes and dust have developed dcim.uitis and ulceration ol the nasal septum. The maximal allowable ronccmi.uion is 0.f> milli gram ol amimonv per cubic meter ol air. a value not likely to lie encountered with the percentages ol anti mony used in lounding today. Beryllium It is only in reicnt years that this metal was rec ognized as an industrial hazard. In 10lf>, 170 cases of illness occurred in certain Ohio bervllimn plants. Five ol these people died. Mans cases have been reported Irom other areas which have been stilluiemlv authenticated. One can conclude that beryllium is very toxic even though the National institute of Health bulletin No. 181 published in 111 la ittdicaied that there is no specific toxic act ion attributable to the bervllimn ion. There are two manilesiatious ol berv Ilium poison ing: tlte acute pulmonarv disease similar to pneu monia and a ilelaved < liemii al pneumonitis now usualIv (ailed pulmonary granulomatosis. Most ol the <ases repot ted in the literature occurred in the lluorcsceut lamp mamil.u ttiring industrv where tlie exposiite was to tiers Ilium phosphois; but six lases ol typical pidntoiiatv disease due to the inetal were teported liom one plant engaged in tasting a V', berv Ilium topper. Four of these six cises died, llcivllium mppei i listing, manuiai lured lod.iv loiitam about ll..'!0' (1 bet \ Ilium' and to date no hazard to lie.dill will] thi'i alios has been demonstrated. Finn) the data presently available, it appeals that mils a lew petsous ate susceptible to (bionic beryl liosis and that mete traces ol the metal in tbc altnosplieie can pioduce svmploins in iliem. A susceptible pci son mas slum svmptoms when exposed to the exirnnels low s.dtie ol out microgijin per cubic meter ol air. Authentic aied "ncighboi hood c ases"-- people who live neat tlte lien Ilium plant--seem to subst.mtiaie ibis, since dies were exposed to cxtremelv low concentrations ol dust. There are no Millie ictii data available upon which to base a maximal allowable fomenitaiion but some investigators believe that in-plant atmospheric tonmutations should not exceed L' mic rogr.cnts per cubit meter ol air as an average lot an eight liom clav, and no one should be exposed to a lomentiaiion in excess ol If j micrograins per c ulm meter ol ait lot ans pci iod however short. These arc extremely minute values and to maintain an environment so free of con- October 1953 55 Building ventilation balance is ol \ r importance in air pollution conrrc This modern ioundry has mu/n-uu%. dust collector uith discharge siac' mold conveyor ventilating hood 0., charge slacks, compensating air su ply units tor efficient operation lamination requires exceptionally good dust control, housekeeping. and personal hygiene. When compounds <>l beryllium come in contact uitli cuts or abraded surlaccs of the skin, deep ulcers .ire formed which arc scry slow in healing and treat ment sometimes requires complete surgical excision iu ellect a <urc. An interesting leature ol berv Ilium poisoning is the delated elfett which sometimes occurs. The onset iitas be delated lot mans months or scars alter the filial exposure ol the patient. Mortality is high. Uciasc of the intsterious nature ol the client ol this metal on man. loundries engaged in the pro duction ol hei t Ilium-Kipper castings--il dies do not hate an indiistnal hsgicilc stall--would do seel I to use an indusiiial htgiene consulting sort ice or their Maic unit ol the 1'. .S. Public Health Settice. st hi; h is liee. in establishing a icgimcn ol atmospheric 11 a it i ol. \s lai as medical pioceduies are cnnciinecl the bil low iiig a i e suggcsied. i l l Pieplac einem examinations. il'.i Periodic ex.mima l mils a Wceklt lot einplotees tc line at me intoxica tion is possible, monihlt lot those wlieie ihiiiiiu poisoning might net in. b X Rat ol chest ctcrt six moiulis. c Special examinations upon piesentation ol complaints hi mi pci sons ulm lute nucleigone sin giial c ipei atimis i I, i I ci mm,11icai examinations. Ihe pi i iodic examination should include tteighl. i ita I c apac lit. In eaill holding test, exannna l ion ol skill, examination ol nose and lluoat. It has been recommended that applicants with the lolloumg abiioim.diiies be rc|cited lor cmplosment tt Itcie a bet t Ilium exposure is possible: c hronic c ough: iluonic tespiiatoit inlet lion: i In unit malaria; disease of litei. kidnets. oi heart: abnormal blood ptcxsiirc. Great stress seems to be placed upon the immediate investigation ol ant stmkci in whom tlieie detelops tough, pain or tightness ol the chest, anorexia, loss of weight, or shortness of breath. 56 Americon Foundrymon Chromium Air contaminated with chtomic acid mist or with chromates or die In timates is the principal exposim to chromium in industry. In this lorm it causes chronic niters and dermatitis. In founding, particnlarlt in the manufacture ol stainless steel castings, chromium is ptesent in the an as the element or as a chromic salt (chromic oxide Cty.O:1). Exposures occur from melting, gate and head burning, and grinding. Elemental thrommm or chro mic oxide have not been conclusively demonstrated in lie toxic. There is some c'identc that this oxide tan be irritating to the nose and throat and both the element and the oxide can pi inline dcnnaiitis. Ssstemic diseases dtTmitcb iiaicd to chromium compounds ate rare. Some imestig.itots have noted a high incidence ol pulmouurs t.ucinnma amongst workers who weic exposed to clnomates rather than to elemental chromium m cluomii oxide. Little dillii tilts Inim chromium has been ex pel tented In the m.tntilac tine ol len o-t hronie cast ings except mild itiitaiiiin ol the nose and throat in susceptible persons winking as burners. The maximal allowable c one etui ation for chromic oxide is II. I milligram pet cubic mciei ol air. This \.due is c-axils exceeded in the case ol unexhausted burning and grinding opei.itions involving ferro till nine castings. Cobalt \o proven cases of indusiiial intoxication have been repented and no threshold limit has been estab lished lot tltis metal. Radioactive cobalt, hciwevei. is now used in the lotmdiv indiixirv in pl.ue ol radium to radiograph tastings. Radiation ha/artls ate the same as those ol radium and the Atomic Energy (.ommission yiH not release radio-active cobalt to i nt I list rv unless the A.E.Cl. saleguatds ate complied with. The set inns elletts ol exposure to excessive radia tion arc well known and the established tolerance close is 200 milliioenigeiis pet week based on a forts hour week. In practice, fouiulrymen using radio-active isotopes s of vital in control multi-wash :,.ire stack, ig hood dts- ig air sup. oeration. i 01 with exposure uses iIn(imt i< ime ot i :n the air imin oxide .mil head i in rhro unM! aicd ihtb oxide uli ihe >>. In omirnn have noted amongst bet than Ik. in ex niic cast (I iliroa: i (In omit in This \ 11.1 usted 111 st terro ........ hair . n csub ad m the . 11111 1 aph .0 thosf .mu wil! '.inks' ihe l l.nlia k-1.1 n | fort; j isoiopfc ,,ill tu- lay- the pmtccriyc rcculaiiom'of the \itiiiii* linngv Commission and other agencies. . _ fluorides } luoiiilc'. sometimes ill the ini in nl irvohtc (sodiiini ,|mu 11111111 lltimiilc) arc used in the ni.nnifaruirc ol (1,,, 11J1 iinn anil magnesium lasting'- Tlicv arc clas.nu ll a- |)l ntuplasmii poisons. \.11 uni' dcgiccs of rcspir.unrv iiiitatinn ma\ result 1.... 11 iJit; inhalation of liiiniiilcs in the form of iluxl. I In. i. ait ninj)a 11 ietl alter a fc"' minutes by a iliv ,li.ni;e limn the nose or nnse bleed. No such effects arc n.ui il when the coin entiaiimi does not exceed 2.5 milligrams per cuhir meter ol air which is the thicsh,,1,1 adopted in tlie I'nitcd States. Dental lliiorosis--mottling and disioloration of the m ih-omns also when the maximal allowable conuniration is exicciled for a long period of time. ( isnlitc i' nituli less soluble in botlv H it ids than 1. .odium fluoride and consequently, the danger of ph'siological cileits is less with cnolite than with the nunc soluble fluorides. In the manufacture of ductile iron or magnesium casting', the threshold limit is casilv far exceeded winch is hazardous. Exhaust ventilation is usually indilated at the station where inoculation occurs. Iron Oxide Fumes and dust of iron oxide occur during melting, limning, pouring, grinding, welding, anil machining operations connected with the manufacture of all fmoti' castings. Exposure is particularly high when manganese steel tastings ate imolvcd. lion oxide is plnsiologii alb inert but it produces a pulmonan londition (tilled sidemsis which is 110111 ir.aiding. 1'ai lit les ol iioti oxide arc radio-opaque and Dinduie nodid.it shadows in a i best roentgenogram tiiat K'scmblc the disirete fibioiii nodidaiiou oT silicosis. As a result cases of sidernsjs arc frequently (oiUiised m radiographic diagnosis with silicosis, a disabling disease, and compensation awards have been made on the basis of x-r.iv cvnlcnic alone when aitual|\ no disabilili was sustained. 1 he undid.11 shadows ol sideiosj. mas be compared I" a latno mail, an the arm. 1 lies aie pcunancni but then, is no loss u| Inin lion. In scserc exposures--Sll mi!!i'_'i .1111s of non oxide per 1111> 11 meter ol nil -- sid.iosi. can he pioduietl 111 as slioit a time as one seal In iounding. the job exposines are in the billowing (inlet of sesents: 1 : r.111 mug. (2.) (.rinding. (.1) Welding (I.) Mu lone gt lulling. (5.| homing. (h.) Melting. I lie 1 ci oinmended maximal allowable i on< cult.10011 ol non oxide cxpiessed as l-c..O is Id milligrams on ( nine meter of air per 8 hour das. In till of the job exposures listed, the threshold limit will usualls be gieatls exi ceded unless adcipiate exhaust xcntilanon i. pros ided. In the itisc ol machine gt hiding "pci alums, exposures (tin sometimes be loiuiollcd b' adding a wetting agent to the coolant. Lead hi non-ferrous founding, this metal presents the ..neatest hazard to health. All compounds of lead tire poisonous hut in saisiug liegiccs aumding to ilieit solubilits ui tissue fluid' 1 In iow lUvidcnic ol had intoxication among niineis <>l galena t lead sulphide) is probabb due to the sen low solubilits of lead, sulphide in the tissue fluid of the lungs. In lotuiili'y pioccsses. it is e\ohec! as lead oxide in melting, pom ing." and welding operations. This is a ten soluble form. Jn 1 leaning ami ni.ulunmg opeta lions, it occurs in the dust lonncd as elemental lead which is not as soluble as the oxide. If atmosphciu concent rations were of the same order of magnitude, the incidence of lead poisoning will he greater whctc the oxide is the contaminant. Lead Concentration The maximal allowable concentration for lead adopted in the I'nited States is 0.15 milligrams pel cubic meter of air. This standard does not take into consideration the degree of solubility of the various lead compounds. In foundry work, if the average atmospheric concentration of the oxide is kept to 0.15 milligrams per cubic meter of air, men can work in that exposure for a life time without experiencing symptoms of lead intoxication. At 3.0 milligrams per cubic meter, poisoning may occur in suspeciible per sons. At 5.0 milligrams per cubic meter, most workers will experience symptoms more or less serious. In practice these values arc sometimes difficult to meet without adequate exhaust ventilation. Even in the manufacture of "pure" copper castings theje is often sufficient lead present as impurity to produce atmos pheric concentrations of lead of the order named. The literature is replete with data on the etiology, diagnosis, control, anti treatment of lead intoxica tion. It is sufficient to state here that in the production of alloy castings containing lead, there is always a serious potential hazard to health especially in the melting, pouring, cleaning, and machining opera- These hooded core sand mixers require only sufficient air volume to convey the dust and maintain adequate ve locity to prevent escape ol dust into the room. October 1953 57 Compensating unilorm flow pouring hood (above) afleets path ol flaming hot gases. Open-side smoke-ofl exhaust hood (below) is made possible by compensating air. High velocity air prevents tumes from spreading. liunv III ,lll\ null III) III!' lasting WOlk. wIll'IC lend is present i s .1 "ii.kc" mcialhngic alls. theie max lie a 11.i/:i111 in he.dill. I c .id i .in ciilci die bndx l>\ ingestion ni l>\ iiihalalinn mi ill,ii even in llie case ul mind dust iniltrol, i;iM' nl 11 .ul 11un\II ;nII111 i .1 n i i III. il hind lv pernulled In lie e.iten in die loundrx in liepudx ditink limn open i niu.imci v. viuli ,iv milk hutllcv. Foods and liquids max .ih'uib lend dnv| and I nine m 'iiliu icilt .mihi111 m piodurc j)<11v<niuiu. lndiivui.il e\peiieiue li.iv show n lh.it vi ii It piactice iv unw.in anted. Magnesium \p.ui 11 nil l 11 v iiill.nnin.ililc ii.iline. m.ignesi mu li.iv nut been shown in be piiivniiniiv ;iv mill, d hi in.iviiii.il .dlnu.ible i uni cii i i ;i t it >n iv )j mdligi.nns pel i nlm melei nl .iii. Ii i c mil explosion iv ;m om-vinnilitiii lin/aul. Manganese Acute intoxication i' .ilmnvt unknown mill iliinnir poisoning. a Mix disabling and venntiv (undition. lx lather i ii 11 ecj ueu t indusii\-w ide. Well eviablivlicd e.ivev l.ul in levpuiid in ueatnieiil. In 1 o1111111n<4. manganese u uvii.dlx awmi.ncd xxiili die produeiion of manganese steel tastings and manga nese bronze. The maximal alloxvable lonienivation 58 Amcricon Foundryman is li.O milligrams pea i ulm nine! nf u, -p| is seldom exieeded m die l"innln uiduvux I Ihe rase wht ere no l 'nnii.ttmn is " *" |i Phosphorus Thisclcment is used in die m.mni.u tun- nl ph<,jlt (upper. Anne poisoning limn ph..vph,,i ,lv |,.|x ' ' been deninnstraied. C.hniuic poisoning n(illh x| lollowing inhalation ol I tunes h iv liehixed q necrosis of die jaw occurs xvlicn phovphm ih cnuiv lf system bv wax of rarimix teeth. Pathologx ,|H. |)( is eharacicrisiii ol poisoning In phosphorus Chronic eases in industrx aie not mitoninion berausc carious icedi alloid a suitable 1 ia( kr-,,,,,, , for the beginning ol the diseasi. pinvunv u,(p dental hygiene should not be exposed tn die ("' lor prolonged periods. Phosphorus ignites sponianennvlx in ,m (() phosphorus pcnto.xide (P..O.) and must be m<1Uii under water. Rcrnuse ol the ignition i hat.icterisd, J burns frequently occur in industrx xs hit h me olten complicated by chronic poisoning bciause the sub stance is absorbed from the binned area. The maximal allowable lonrciut.uinn is D.l niilh gram per cubic meter ol air. This limn max casilx be exceeded during the phosphoi i/ing phase of melt ing phos-copper. Local exhaust xeinilatiun is usuallx indicated. Resins With the advent ol shell molding. morercsins are used. They are ol the thertmiM-tting type. That is, once the resin is c ured. it lannot be sol tenet! or re molded. There are various types on die market such as the phcnol lormalilehvilc and tnea formaldehvilc resins. Some contain hexamethx Icncieti amine. The phcnol-lormaldchxdc resins on heating give ofl odors ol phenol and lormaldehxdc. I'rea decomposes io ammonia anil carbon dioxide so that in shell mold ing one ol ten notic cs a (list iuc t odoi ol ammonia. Hexametlix lcneteti amine icleaxex loi maldehxde. All of these are poisonous, but in si-xcio concentrations. man cannot loleiatc diem. In practice then, lumev (torn the resins will be at most a nuisance lather than a ha/attl and the degree ol nuisance "ill indicate whether exhaust xeniilaiion is juxiiliable. All resins are piiin.ux skill iiritanis and arc capable ol produc ing deim.nitis in siiscepiible pet sons. Sea Coal This is a common lacing used in the loundrv and usuallx contains less than 1",. lice silica. It is prin cipalis c ,n bon. C.aibon dust gixt-s i is( io a pulmonarv condition called aiitluacosis which is lesponsible for c harac tet istic shadows jn a chest r.itliugiaph. It has been consideied as a lelatixelx li.u inless condition. Rcient tcseatch. however, has indicated that it may be a true disease. When carbon dust is associated xxith silica dust as an atmospheric contamin.ml--and it usuallx is in foundry prauicc--an exposure texulix that is capable ol producing a tine disease cniiix known as siiicoaiithrac osis. Permissible dustiness for sea coal and loi mixtures of sea coal and silica depends on the pet tentage ol i . ! \ .due " II) I n nil'll. ir lot i< IU |\ lllJI hi ' the I miles mu] _ i < >tincl | poor miles Imm med 'tics, 'I ten : sub- n ini s'. isily mch i! 1 v - -ire ' is, m re- -h e is i- of! ii ncs mill- i U'\.l .H of m.in i the ! i. m n Ik ntc * 1 ilc . .i nd pnn 11.11 v for r. has : i hin. m;i\ imt ns i' in able ...es e of 11ci >i 1 k :i picM iit. Safety (actors me variable. \ i,,i mill,i commonly ii'Ctl lor determining live iii,in.iiii.i1 allow.ible inmcmviniiiii Im a mixed dust i. a I(i! hiu v nlii'1 < mini louiiil) fiee silica) S limir dav j u million panic lex i u. fi. ol nil S Imm vlav liii'iiH'i. even though liv illi> formula, a supposed ,alc ainins])hi*ie (iiiilil lexull vviili a dust (mini ol l(N> niillmn panicles pel cubit loot ol an. lor pood in,hi'ii i.d h'pieiie ami an acceptable en\iionnieiu. a (hm i oiim should nc\Cl exceed `>0 million panicles 1,11 iiiim Idol ol air pel S lioui dav. II il dues. diN dim i ol i' in.idi (jiiaie. Silica Siiii.i i' one ol die piimipal aimosplici it com.uninaiil' in die lmmdiv. I lie ilieniK.dh iiniibiiieil silicas, oih'.i di.ui asbestos. me leg.oiled ax being plivMolog nail' men I Ini' 'i i k mci mic Ii as ben tom lev slap wool, im . me noi known io piodiue disabling disease. Till mIk.i i Nil) i di ies ( a use die oi i upa I iim.i 1 d ixi use known a' sduosis uliuli is i hai .u lei i/eil l .uhogi aplinail', pi mi ip.dl\ b\ nodiil.il shadows due to Hue filnosis ol die limp ipssue and (hull.ills l)\ dei lease of |)iiimonai\ I uni i ii hi. It < mi he disabling h i- cspc ii. ilb sei urns when m (ompamed l>\ luheiiuloiis in 1 tl I loll. I mi.ilb diiec Im tors mnsi he piCsent simullaneoush in pi odui i die disease: il i Dm.iiimi ol exposuie. Two lo twcim \eais me ieqhm ill depending on degree of exposure. i-.l Respirable pmliile size. Partidcs of free silica in exuss ol ."> mirroiis in diamcicr are not regmded as ticmp plnsmlopu alls sipnifuaiH because dies me loo ;upe io le.uli die abeoli ol die lungs wheie chemical tent lion ixi ms. in ) (.oiiieniiadon ol dust. The tolerable conccniration de]iends on die percentage of free silica in the dust. The formula used under "Sea Coal" ma\ be ap plied here. In non-ferrous founding, the lva/aid from silica dust is usually not severe except in the case where silica washes arc sprayed on molds and coies or sand con ditioning practice is uncontrolled widi respert to ven tilation. The low incidence of silicosis in non-ferrous work is due to the facts that: live sand is ustiall\f in a tempered state during shakeout; there is seldom nnv burn-in; castings are often shot or sand blasted bclore gi inding ami c hipping. In let runs founding, one of the gicatest sources of exposure is the uncontrolled use ol siiira Hour. This material falls in the dangerous panicle si/e range and is usually 100*/,". free si I im. /in unite, which is non-toxic and has a specific gravity ol approxim.uelv twice that of silica, has been an effective substitute lor silica Hour in some applications. Keen use ol its densitv and tendcncv to Maculate, /iiccnntc dust settles ven i.ipidlv. Sand handling and c oiuliiionmg svsirms. shakeout, and sometimes sand slinging open alums ccmslilinc the j> iiic ip;iI exposuies lo silica dust. Dust sources ate usuallv more scveic in mechanized plants Imt this is offset In the Imt that then me mole adapted lo local exhaust svstetlis. C.ood housekeeping is one ol the most important wavs cil c emu oiling the hazard limn silica dust. There is good evidence in the litcratuic that the incidence ol silicosis is inveisely pi open tiona I to good house keeping. T lie higher the level ol housekeeping, the lower the mmiliei ol cases ol occupational disease. Silicones In founding, silicones arc used as mold release agents during shell molding, lixpcricmc to date indicates that thev are not a sciious hazard to health. Nun hvdiolv/ablc silicones used as mold release agents are ol ;i very low older of toxiiitv. From a practical view point, the hazards Irani handling them are exceedingly minor. However, silicones are new October 1953 59 chemicals mui sufTicicnt toxicological 'indies li:ivc not I iff ii made to enable us to state that the non-hytlrolyziuj ivpcs can lie ignou-d. A11 Jiontjli the non livdiolizing ivpcs of silicones apjic.ii ncithci toxic nor u i hating, the h'lholvzing ty|>cs ,ne higlilv tunosne. Fiom n pi.it tic.'il view point, they I)icseut hazards liom \ajioi inhalation and contact with the skin and cvc-s. In dangerous contentrntions nif\ have adequate warninq jnopcitics so that a man i on Id not tolerate an atmosphcic that would be harmIn! to him. Gate should be used in handling the hydrolyzing t\ [ics sintc a small drujilet splashed in the eye could taiise sci ions damage and e\cn the loss of the eve. Ducrt skin contact while likelv to cause a severe burn is not ajn to cause death unless a large portion of the bodv is exposed. Because there are many kinds ol silicones available, sale jjiactices indicate that those of a low order of toxititv be used as mold release agents. These are the inethvi, mixed methyl, and pheny lpolysiloxancs. Solvents (General) Since there are so many solvents used in the foundry , it is impractical to treat them specifically here. There is no such tiling ns a sale solvent, excejn perhaps, w.uci. Some ate more toxic than others but all ol them tan be used safely if the poisonous properties are known and safe handling procedures are followed. All containers of solvents should have labels at tached. giving the chemical name and stating the han dling precautions. For example: M \\ CARBON TETRACHLORIDE DANGER! Hazardous vapor and liquid BE FATAL IF INHALED OR SWALLOWED Use onlv with adequate ventilation. Do not use in confined unveutilated places without protective rcspiraton equipment. Do not lit e.ulie vapor. Avoid piolongetl or repeated loniatt with skin. Do not take miernallv. Fire and Explosion Most solvents are flammable so that in addition to then toxic projiei ties, they present the tl.mget ol file 01 explosion. Coven the ihemital (not tiadei name of llic ingle tinaits, the < hai.ictci isties anil d.mgci.v of the solvent tan be asiei tamed. There is a wale range ol threshold limits because ol varied loxicitv lactois and maximal allowable concentrations range liom 3 pans per mil lion lot nutobcn/cnc to 300 pans per million for petroleum naphtha. Sulphur Dioxide Sulphur which is used as a tleoxidant in the manuf.Kturc of magnesium castings bums to sulphur di oxide. Bicabling zone concentrations of the dioxide dm mg the production of magnesium castings varv. A concentration of 10 parts per million is common and of 50 pans per million rare The M.A.C. is 10 parts per million. 60 American Foundryman ( uimnuetl cxposiuc m t xtC's <,| ihc \| \ (p j>ro,|u inll.nnaiion ut the i cspnuim v sv in. m* rcascd excess acid 111 the m me and ahn.itmn ol the seiist ol smell and taste. Exjronnes to i out en 11 a i ions , ,| i |K m de i ol 3Uli |,,n . per million aie tl.mgeimis n, hie In loundmg. u. value will not be leacheil and uinu'iiii.iiiniis m cxu. ol the M.A.C. are imoleiable to man so that he v not temain in an atmnspliete d.mgeioiis to hie. The gas nt.nv lie rcg.ittied as an n mam ntus.ui,. and dcjrcnding on degree, exhaust ventilation nt.iv p. indicated. Tellurium Tellurium is used in found t v pi .n me to me tease thcliill tlepth hardness of chilled cai wheels, and tc ],M jjt'ovc the machincabilitv of allovs. It is usually used in very small amounts (3 grams m 800 lbs. ol metal The fumes of the element tattse poisoning chai.u terized principally by the garlic odor of the breath and urine, stijqrression of sweat, divness of the mouth metallic taste, loss of ajqictite, salivation, and vomumg. Serious industrial jroisonings ate late. Systemic Poisoning The maximal allowable concentration is 0.01 milli gram j)cr cubic meter of air. It loul bieath is to be avoided, this value should not be exceeded. Svstemic poisoning does not occur unless the exjiosure is to a concentration of 0.S milligrams or mote per cubic meter of air. . For practical purposes then, the |>icscnce or absence ol tellurium breath can he relied-upon to measure degree of exjzostiie. If this is heeded as an indication of the need ol control measures, in jut ions exposures arc not likely to occur. according to l'attv. This is con firmed by the cx|>erience of otlteis. Tin This metal is communis used in allovs. It is consideted non-toxic. The inhalation ol tin oxide over long |)eriods may resit in a lu-nigu non-disabling pneumoconiosis known as stannosis. No cases have been rcjrorted in the lomulrv imlusttv. In |)iaciitc, it docs not jnescni a health jnoblem. No maximal allowable t out eniratiou has been estab lished. Zinc The inhalation ol the lumes ol zinc oxide .gives rise to a malaria-like illness called In ass lmmdets ague, zinc thills, smeller shakes, or meial fume fever. Recent reseatch has now shown that itnelv divided oxides of other metals, such as magnesium, can also jwoduce metal lume fever. The illness rarclv lasts more than a day, causes no permanent tlisabilitv. and is never fatal. Immunity is olteit :i<cjuircil alter rcjrealcd ex posures. When brass contains zinc, fumes of the oxide are readily given off during melting and pouring in vo luminous amounts because of the low boiling jroint of the metal. The maximal allowable concentration is 13 milli grams jer cubic meter of air. TRANSACTIONS of the AMERICAN FOUNDRYMEN'S SOCIETY .a Proceedings of the Seventy-Eighth Annual Meeting, May 6-10, 1974 'm & "***. ft ' VOLUME 82 1974 AMERICAN FOUNDRYMEN'S SOCIETY GOLF AND WOLF ROADS, DES PLAINES, IL 60016 sj: Silica Content of Foundry Dust based on the quantity of crystalline silica or quartz in the breathed dust. OSH A has established the following limits for mineral dust in foundries: by George Krafcisin, Environmental Consultant, National Loss Control Service Corporation, Long Grove, Illinois Quartz (respirable) Limit = [0 mg M' rt respirable quartz -t- 2 ABSTRACT This paper gives a general introduction to the importance of owing the silica content of foundry dust, the methods used to ermine it, and some of the problems associated with the determination. Characteristics and Health Hazards of Silica Silica is SiO:, a mineral which, when inhaled over a period of many years m the form of microscopic dust particles, can cause a disease known as silicosis. Most foundrymen are somewhat familiar with this fact. The silica which causes this disease is known try many other names: quartz, crystalline silica, or many commonly used foundry terms, such as bank sand, beach sand, core sand, dune sand, quartzite, sandstone, sharp sand, silica flour, silica sand There is also a form of silica called amorphous silica, which does not have a crystal structure and does not have the property of producing silicosis. There are two slightly different crystalline forms of silica called tridymtie and cnstobalite. which are formed from quartz upon heating. Quartz turns into mdymite at approximately 1600 F (861 C). and indvmiie into cnstobalite at about 2700 F (1470 Cl. Tridvmitc and cnstobalite are both considered to have a much greater tendency towards production of silicosis than Joes quartz. Related to silica are the silicates. These are generally considered non-toxic dusts However, asbestos is a silicate sometimes used in foundries which is capable of causing serious Jisease Also present in foundry dusts are many other minerals and other types ol dusts, which are called nuisance dusts, and have little or no physiological effect on the body, Examples are ilundum (Al-Oi). Portland cement, graphite, gypsum, etc. he health hazard presented by dusts suspended in air in a .dry can be esaluated by knowing the amount of quartz in 'ne dust. For this purpose, the amount of inert or nuisance dust >resent can almost be ignored, and health evaluations can be Quartz, (total) Limit = 30________ ' i total quartz f 2 mg M' Tridymite and Cristobalite Limit = one-half quartz limit Nuisance Dust (respirable) Limit = 5 mg M' Inert (total) Limit = IS mg M' These limits represent the amount of dust in air to which a worker may be exposed without running the risk of adverse health effects. Of the five limits given above, the one most commonly used is the one for respirable quartz. A sample of the air a worker breathes is taken using sampling equipment which separates out the panicles too large to reach the lungs, giving the concentra tion of dust to which he is exposed (Figs I and 2). The silica content of that dust is then determined, plugged into the formula to give the limit lor that dust, and the limit and the air sample are compared. The limit for total (respirable + non-respirable particle sizes) dust is used less frequently, because it does not reflect as accurately the health hazard of the dust being evaluated. The limits for tridymite and cnstobalite are not used frequently because of the difficulty of analysis for these two forms of silica. More about this later. The inert or nuisance dust limit is not used frequently in foundries because almost all foundry sand contains more than IQ crystalline silica, which necessitates the/usc of the silica limits. I he nuisance dust fraction ol the total dust may then be ignored, since it contributes practically nothing to the overall health exposure. Distribution ot Silica in Foundries Unfortunately, there is almost no rule of thumb which can be applied to give an idea of how much silica is present in the dust associated with a given foundry operation. From the results of 55 settled dust samples obtained Irom 13 foundries over the past AFS Transactions 74-81 145 Deposition Fraction Deposition in Respiratory Compartments 0.01 0.05 0.1 0.5 1.0 5 10 50 100 Mass Median Diameter - Microns Fig. 1. Araa ol lha lunga where different particle stzea are deposited. (Copyright 1973 United Stales Steel Corporation). PENETRATION OR DEPOSITION, PERCENT Fig. 4. Cassella cascade Impactor lor size separation of dust. Fig. 2. Comparison ol size-selective air sampling criteria and pulmonary deposition. The BMRC and AEC curves are the percent of particles of a given size which pass through a sampling device, such as a cyclone, to be collected on a filter. (Copyright 1973 United States Steel Corporation). Fig. 3. MSA Model G pump with 10 mm nylon cyclone and filter assembly for breathing zone sampling of respirable dust. 146 5 years which were analyzed for crystalline silica, we have foui that the silica content of foundry dust is highly variable ai must be evaluated on an individual basis for separate foundri and operations. The range for all 13 foundries and S3 samples from 0.4% to 75% crystalline silica. However, over a period time, the analysis of a number of samples will give a reasonab good idea of the silica content of dust in a given foundry. There are many reasons for this wide range and high variati< in silica content of foundry dust. The major reason is that the are different formulations of foundry sand for specific types jobs. Some foundries find it possible to conduct their busme without using any.silica sand at ail; olivine, a magnesium in silicate, is an example of a substitute for silica in non-ferro operations. Chromite is beginning to be used in steel foundru and aluminum silicate, zircon and carbon sand have been trie hut are not widely used. Another reason for the variation is that the dust frt different foundry operations mixes in air. Very few foundr have their molding, shake-out. cleaning, and sand mixi operations completely isolated, so that airborne dust from o operation will drift into other areas of the foundry. A third reason is that dust particles have different sizes, a the large-sized particles settle out of air much more rapidly tb very small ones. If the large particles have a higher silica conti than the small ones, after the big particles settle out. theairboi dust will have less silica than the total dust in the foundry. 1 variation of silica content with particle size depends on i characteristics of the silica, how it has been used, whether it I been fractured into small pieces cr does not fracture as easils the other minerals used in the foundry sand, and a host of ot characteristics. Another large variable in the process is the exact methoc collecting and analyzing the dust. The next section gi information on these methods. AFS Transact!! Fig. S. Unlco Model 30 high volume pump lortotal dust sampling. Tridymite and cnstobalite are known to be present in some foundry sands, but there is little data available. An AFS committee is developing a paper on the subject of silica conversion. They are not thought to be a significant problem in other than ferrous foundries, because it takesa good deal of heat for a long period of time to convert quartz into tridymue and cnstobalite. This time and temperature criterion is commonly assumed to be filled only in ferrous foundries because of the higher temperature of the metal, and then only in castings weighing on the order of 1 ton or more. The quartz present at the interface between molten steel and the mold may be convened over a period of many hours to ridymite and cnstobalite and stick to the mold. It then produces very significant hazard of silicosis to workers involved in the .eaning operation, because of the difficulty of ventilating a cleaning operation on a casting weighing several tons. It will also contaminate the recycled sand, exposing other foundry workers. Evaluation of Silica Content of Dusts Obviously, the best way to determine the amount of silica dust to which a worker is exposed would be toanaivze the dust which he breathes. This could theoretically be achieved by taking a long term air sample at the breathing zone of the worker throughout several hours or periiaps several days of exposure, weighing the dust collected to determine the extent of his exposure and then analyzing the dust for silica to determine the appropriate limit. The sampling equipment necessary for collecting the dust is available and is very commonly used for evaluating dust exposures. (Figs. 3 and 4). It is difficult to collect enough dust on a filter to make an analysis of the amount of silica contained in the dust. This is because in order to be portable enough to sample the worker's breathing zone, it must be of a small size, which limits the capability of the equipment to sample large volumes of air. The problem has been skirted by two methods: one is to use a stationary sampler powered by line current which is capable of taking a very high volume sample of air. and collecting a large quantity of dust; the other is to find a location in the foundry where dust has settled out of the air and has remained undisturbed. A few grams of this settled dust may be collected and analyzed. Under ideal circumstances, the dust collected for silica analysis should represent the particle sizes which are capable of SIZE SELECTIVE CHARACTERISTICS OF NYLON stageFraction retained -first (10 MM) CYCLONE 1.0 0.8 Fig. 7. Size selective characteristics ol 10 mm nylon cyclone. (Copyright 1973 United States Steel Corporation.) 0.6 0.4 0.2 0 *FS Transactions 147 entering and being retained in the lung. Obviously, collecting settled dust would only be an approximation of this. Collecting all airborne dust by a stationary sampler would also be only an approximation, since some of the dust would be in the processor settling out. and some of the dust would be airborne but still have particle sizes too large to enter the lung (Fig. 5). Devices have been developed which automatically screen out panicles that are too big. and pass only those which would enter the lung. Several devices have been developed with are called size selective samplers, including the half-inch steel cyclone for high volume size selective sampling, the ten millimeter nylon cyclone for personnel monitoring. (Figs. 6 and 7) and a number of other devices such as elutriators. cascade impactors. etc. (Figs 8 and 9). Analytical methods for silica content of dusts range from the Talvitu methods, which are basically chemical methods depen ding on t he different solubilities of crystalline and other forms of silica and other minerals: x-ray diffraction, which uses an x-ray beam to measure the amount of a certain crystalline structure in the sample: differential thermal analysis, which depends on the amount of heat absorbed by different minerals at different temperatures, petrographic, which is a microscopic technique which counts particles of different mineral species: and infrared, which depends on the absorption of different wavelengths of light by dillercnt minerals. Of these, the Talvitu methods have been the most commonly used. Their primary disadvantage is that with mixtures of different minerals, the crystalline silica content determined may vary considerably from just a slight change in the amount of lime taken in some of the steps, or theexact temperature utilized during some of the steps. 1 he Talvitu methods also take a large amount ol lime per sample. X-ray diffraction seems to be the wave of the future in silica analysis It has been used quite successfully for analyzing bulk samples, such as settled dust samples, and is very accurate in determining crystalline silica. It can determine not only quartz, hut also cristohalitc and tridymite. and can be used for distinguishing many other types of species in this manner The question ol accuracy of x-ray diffraction for very small quantities, such as those collected on a breathing zone sample from a foundry worker, has been raised, but many workers in the field believe that this has been solved, and that x-ray diffraction is the method of choice for this purpose. X-ray diffraction equipment is very expensive, but it is much more rapid than chemical methods and thus less expensive for large sample numbers over a period of time. The other methods mentioned above all suffer from some large disadvantages, primarily problems arising from in- 148 SCHEMATIC DIAGRAM 1 Fig. 9. Schematic of horizontal elutrlator. Large particle* aettle out In the horizontal portion of the device. (Copyright 1973 United State* Steel Corporation.) terferences from other types of minerals present in the sample. Conclusion The silica content of dust is an essential piece of information in the evaluation of health hazards in foundries. It cannot be guessed at. but must be determined by competent people who have the facilities for performing an analysis and the ability to recognize the limitations of various methods of sampling and analysis and take these into account in their evaluations. References 1 I* Drinker and I. Hatch. "Industrial Dust" McGraw-Hill. 2nd Edition (19541. 2 Aerosol technology Committee. American Industrial Hygiene Association. "Guide for Respirable Mass Sampling.- AIHA jour nal. Vol. 31. p. 1.13-137 (Mar.-Apr.. 1970) 3 M. Lippman. "Respirable Mass Sampling-. AIHA Journal. Vol. 31. p. 138-159 (Mar.-Apr. 1970). 4 G. knight A K. Licht. "Comparison of Cyclone and Horizontal Elutriator Size Selectors.- AIHA Journal. Vol. 31. p. 437-445 (July- Aug. 1970). 5 H Bumsicad. "Determination of A.pha Quartz in the Respirable Portions ol Airborne Particulates by x-ray Diffracuon.-AIHA . Journal. Vol. 34. p. ISO-138 (Apr. 1973). i- 6. S I alvitit. "Determination of Quartz in Presence of Silicates taint Phosphoric Acid.- Analytical Chemistry. Vol. 23. p. 6231 Apr. 1951)., AFS Transactioos. TRANSACTIONS of the AMERICAN FOUNDRYMEN'S SOCIETY Proceedings of the Eightieth Annual Meeting, April 26-30,1976 VOLUME 84 1976 AMERICAN FOUNDRYMEN'S SOCIETY GOLF AND WOLF ROADS, DES PLAINES, IL 60016 Determining Crystaliine Silica Compliance Using Respirable Mass R. . Zimmerman. Occupational Health Chemist and J. M. Barry. Industrial Hygienist Division of Health. State of Wisconsin ABSTRACT This study examined approximately 1275 samples of respirable mass and crystalline silica collected under Wisconsin OSHA compliance sampling. Information was developed to estimate compliance with OSHA crystalline silica standards using respirable mass without crystalline silica determination. This is a much less expensive method of determining the probability of compliance with the need for a minimum amount of actual crystalline silica determinations. Average free silica concen trations are presented for the various foundry areas and job descriptions as well as percentages of samples that were not in compliance indicating common problem areas. Introduction Free silica determinations using x-ray diffraction. colorimetric or infrared methods need trained operators and expensive equipment not available in many small Wisconsin foundries. Commercial availability of membrane filters, battery' operated pumps, cyclones, and relatively inexpensive accurate microbalances have changed the evaluation of dusty at mospheres from total impinger dust counting*' to weighing membrane filter respirable mass which can be performed rapidly and with much greater reproducibility between operators in different laboratories than impinger dust counting. NIOSH* has proposed changing the current free silica standard (standard = 10/% free silica + 2) to 50 micrograms for, alpha quartz. This would necessitate the free silica determina tion of every sample collected and call for routine air sampling and medical examinations for all employees exposed to more than 25 micrograms of quartz or 12.5 micrograms of crystobalite and tridymite. The idea of respirable mass as a single indicator would be much less expensive than free silica determinations and may be performed in even the smallest foundry with little operator training or time. With this in mind the authors decided to review compliance samples collected in the State of Wisconsin. Respirable silica samples were collected over approximately a 1-1/2 year period by field industrial hygiene compliance officers under a Wisconsin-OSHA* 7(c)(1) compliance program. A 7(c) (I) compliance program is essentially an agreement between the participating state and the U.S. Department of Labor whereby inspections are conducted under the federal program with the state personnel being "on loan" to the Department of Labor. Funding in this case was 50-50 by the parties incolved. Inspectors were supplied by the Section of Occupational Health of the Wisconsin Division of Health; the Wisconsin Department of Industry. Labor and Human Relations; and the Wisconsin Area Office of the Occupational Safety and Health Administra tion. Sampling Methods The OSHA target health hazard program10 includes silica as one of the substances having proven widespread potential for disabling lung disease, so during the course of the programthere was considerable emphasis placed on silica sampling. Com panies inspected consisted of 65 Wisconsin foundries employing the majority of the State's foundry workers, and 20 other manufacturing facilities that used silica in various processes or operations. AFS Transactions 76-12 15 Table 1. Breakdown of Data Into Job and Area 100 OLTItt AREA fwroae* 10*4104 eweui* ogmwf * ifcirtc ere fureaee agtnur iMueuoo NP*w apeeator i*4 M red f\ree eparator lr* 1*41* ltnt*4 Mil ladle U**d cr*M operator 35 t 1 1 1 1 15 *7 7 rcjxiie mu 47 naed pourla* eriM egtnur eeatrifoa*! eeetio* U 19 70 1 3 ajq rrrrex 7 ullor operator frit Mr ifttMOvi operator payioadcr (boacat) frl9* ttlliftl ard earner (aylloarrwz) t>o*exer 107 47 lit ?3 a 3 rCADUXlRC AALA 93 owLlor operator ei. e*M core a**r Mil eora aiiar no MM eon blowr operator helper eor* riaiahia# *ad aaeeoel? 39 15 15 5 10 1 13 M0LS!IC AREA 704 *4floor aoidiot Itrn core Mttl rldia< *ao4 alioter eras* operator eU autooatic as141*4 oper. core ttia4 taaall} SK> aoldiac eope/Ar*4 nUtr ljr|e MlsMtlc aoldlt# over. *ue#Mr aolder Mil ao14104 no Me* 0014104 M44 sperater ait#er ope** helper tooldio4> general aoltia* 9 4 17 17 15 7 3 il 3 5? ? ? 12 15 75 :UA4DC oor woeeloorotor tan4 4rlo4er no4 cnipper-crtader tneueui operator hooaovt oao4 inaoer o*4d cbipper aaterial naadler. Hot itepeetor-sorter iOf fraoc prioder enn off cr*oe operator *ora*ie 0i04tl04 belt *M*a*r \Mll04 barrel operator flar cut-off m14104 crf104 ** bo 57 79 e 72 65 a 7C U It lb U 0 a ; 3 jrcruAous 75 n*oO avorpt04 power sweeper helper tgenerti) laborer le> ? PC !*R.T?*T CTKE7 TKAP K}jn*l 8J at aer eruenrr or gnn4w^ aaen.oper. ino4;o4 alllea eontetnin* aaer material atita* 4 euttih* baa* Mtertal nsndisei powaers ' 17 l." 1* 4 tapMi kiMiiai 119 96 17 100 0 100 *0 96 100 19 6 21 25 0 33 *7 50 7? 04 9 7* 75 100 r 94 20 20 60 0 0 JB 30 72 90 75 75 c 29 33 It 6e 15 0 96 33 66 46 33 75 59 4* 3 25 56 l *5 56 33 50 67 100 100 40 90 - * i* s. 7* 33 3i awe cape ^ Pm Stiles 7.|6 7.96 0.66 1.63 10.73 6.6o 6.96 2.76 3.78 6.00 3.61 6.69 5.93 9.99 6.10 6.95 9-99 a. 6 9.06 11.31 6.61 6.59 13.20 3-96 7.64 e.73 6.66 5.27 4.21 a. 3" e.70 2.36 5.77 9.64 3.6C 5,09 9.65 0.60 12.96 5.76 3.96 5.76 b.97 6.)6 :.?l 13-33 ".76 7-lb 5.7C 7.2, . .t 2.50 15.76 IC.'? l.OC .67 22.16 12.61 b.i* 0.a l-.U About 1275 sample*, excluding blanks, were taken for a determination of respirable mass and percent alpha-quartz. Locutions selected were not representative of particular operations, but were sampled because they appeared to have the greatest dust exposure and consequent potential of being the greatest health hazard. Statistical methods were not applied because the samples were not random. The sampling was conducted with nvloncyclones and holders using two-part 37-mm cassettes with 37-mm thick absorbent filter pads and 37-mm 5 micron pore size polyvinyl chloride W SO 70 60 SO 40 oypuu. ALL KDU5TFT s0 CUT 1*0* FWtORlC I STIXL FWRMtES 0 mauxable pouiorxes MAT*. SAORZE ro.'WDfflE* All*IPL* FOUTOIT!? POURIJC AREA -. . -r - - i - . kr- u'** * ' i rn . n* It*' tv r . t - ' The MMrri abMe am coIsam Indicate tnr total nwaMr'of Mpltl . Fig. 1. Pouring area. filters. The air sampling pumps had been modified to include a pulsation dampener and a larger battery pack. Pumps were periodically calibrated. The sampling devices were placed on individual employees, with the cyclone attached in the approximate breathing zone -- usually clamped on the worker's collar. The individual workers were instructed to work in a normal manner, and to keep the sampler in place during operation, rest periods and lunch break. The inspector removed the device, usually at the end of the workshift. Close observation was made of the sampling device to ensure the continued proper flow rate of t.S liters per minute, and reduce the possibility of tampering. Most of the inspections were made using a team approach, where 2. 3 or up to 5 inspectors would he sampling in adjacent areas, so overlapping observations were possible. The number of inspectors on the team was dependent on the size of the company and number of sampling sues. The team approach was complimented by several ot t he larger foundries inspected because management and labor felt this method of inspection was less disruptive than having one inspector in the plant for weeks on end. Sample volumes ranged from 50 to 950 liters, the majority falling between 550 and 900 liters (as shown in Table 2) or 5 to 8I 2 hr. Inspection-typesamplingisdoneforextendedperiods -- the whole workshift. if possible--to obtain representative samples because the larger sample size increases the accuracy of the analytical procedures. The niters were weighed on three different balances one of which had weights to the nearest one-hundredth of a milligram 16 AFS Transactions Fig. 2. Melting departments. Fig. 3. Sand ayatem. and the others weights to the nearest microgram. Initial and final weights were made on the same balance. Comparisons between two of the balances showed no difference. In all weighings static bars were used to remove static electricity. The samples analyzed in the Wisconsin State Hygiene Laboratory were by the Talvitie4 method or by x-ray diffraction, with x-ray diffraction being the method of choice. Some of the samples taken during the program were submitted to the OSH A Laboratories at Salt Lake City. Both laboratories have par ticipated in the Proficiency Analytical Testing Program by the National Institute of Occupational Safety and Health with comparable satisfactory results. Both laboratories use both procedures and there was no attempt to separate samples by laboratory or by method or any combination of these variables Results Sample results were tabulated and fed into a computer at the Wisconsin State Laboratory of Hygiene. Information included was: company, date of sample, sample identification number, volume sampled, respirable mass on filter, respirable mass per cubic meter, percent free silica, shift during which sample was taken. Standard Industrial Classicifation (SIC) number of the company, general work area of worker sampled, primaryworkstation. and secondary workstation. The allowable respirable dust was calculated for each sample according to the Occupational Safety and Health Standards." section 1910.93. using the formula 10-mg' M1 divided by percent free silica plus 2 A comparison of the actual respirable dust to the allowable AFS Transactions was then made and computed as a percentage of the standard. For example. 70% would indicate that the sample was within allowable limits or 0.7 of the threshold limit value (TLV), and 150% would indicate an overexposure to silica dust or 1.3 times the TLV. Various sort routines were programmed to arrive at some trend indicators. The results were separated into SICcode. area, and workstation. The more common workstations and general work areas, according to type of foundry, are depicted in Figs. I6 according to the ratio of samples taken that exceeded 120% of the allowable respirable dust concentration for the particular samples. 120% was chosen as the upper tolerance limit to take sampling and analytical tolerances into account--that is. a result exceeding 120%: of the allowable is a violation of the OSH A standard even with maximum random errors. Figures I 6 can be looked upon as the odds of receiving an OSH A citation in a particular area or at a particular job. Many of the seventysome job classifications are not given individual treatment due to an inadequate number of samples taken. They are included in the overall percentages for each area. Table 1 in the appendix shows the breakdown of jobs into areas. Figures 1-6 show that several jobs are generally hazardous and should be looked at in all foundries. These include ladle lining, muiler operations, working in pits below shakeouts and shakeout operators. The cleaning room is generally dusty, but a lower percent quartz permits more respirable dust. It is interesting to notice that hand-chipper-grinders have a 68%> OSH A Standard violation rate, but the hand grinders that do not chip have a 479c violation 17 ICC *5 mi ^UL--- ' MOB-a--OC 3 i i \ i/ s/ si !- |j Fig. 4. Coremaking. /s /V * /V rate This may be because chipper-grinders have to work on dirtier castings, and the exhaust from air powered chisels may help to blow the dust out of casting cavities and into the breathing /one. whereas grinders usually have peripheral exhausts that have less of a tendency to kick up additional dust. Apparently steel foundries as a class have the highest overall risk Steel is generally poured the hottest of the primary metals. This converts some quartz to crystobolite which has a TLV half that ol quartz In addition the higher temperatures cause a larger percentage of the respirable fractionto be alpha-quartz possibly due to temperature fracturing of the quartz crystals, con tributing to higher free silica content of the respirable mass Steel foundries generally make larger castings, reuse sand indefinitely and have to employ more and heavier risers and gating systems Steel castings are also hard toclean. and thejob shop nature of the industry keeps automation or standardiza tion of products out of the picture. Collection Efficiency The data was examined to see if the length of sample time had any effect on the collection efficiency, which presumably would show up as increased respirable mass per cubic meter with increased sample time. The data was sorted into 50-ltter steps by number per step and average respirable mass. Table 2 indicates no trend that is significantly valid. The three groups from 250 to 400 liters appeared to be abnormally high, but there were not enough samples in the particular groups to draw a conclusion. e Hazard Classification Guesstimation (HCG) Somewhere between "I can't breathe for the dust." and "This is like a garden." lies "I wonder if that dust is bad news." As with most airborne contaminants, nasal analysis leaves much to be desired by way of accuracy. Table 2. Average Respirable Mass Concentrations by Collection Volume Liters !Collected l.d ;L.lters/Mln. Number of Camples Avenge Respirable M. m*/>r 50 100 100 150 150 - 200 200 - 250 250 - 30C 300 350 350 uoo kOO U50 t*50 - 500 500 - 550 550 - 600 600 - 650 650 700 *'00 .750 750 . 800 900 850 850 900 900 950 1 2 1 3 u 5 11 Is 12 12 2C 66 152 267 369 196 116 15 1.93 1.55 1.0k 1.1*9 5.16 It .6k 10.20 2.92 1.53 2.25 1.7k 2.0b 1.85 2.k2 2.20 2.21 2.11 1.6k T~C T, imifioi. ui.jjit -jK ianjci IOC QC ajc r'nfrrt cursor* ryan CRirao Fig. 6. Cleaning. Accuracy in hazard determination can be expensive--for instance, a determination of free silica content by a commercial laboratory is about $50. The authors felt that it could be economically beneficial for a company to use respirable mass to determine the likelihood of having a health hazard without having to analyze each sample for free' silica content The major areas and workstations were split into three categories, using respirable mass meansand ranges If the actual respirable dust concentration was less than 809b of the allowable for the particular sample, the sample was put in the safe category, those greater than 1209b in the hazardous category, with the remainder put into the marginal category. Samples with more than 10-mg'M' were rejected, as they are a hazard For each area and job. a mean and range (with I Of? of the "out hers" eliminated) were determined for the three categories, using only the amount of respirable dust, and not the percent quartz The three categories were consolidated into the bar graphs (Figs. 7. 8) for use in plotting a known respirable mass with an unknown percent quartz and coming to a reasonably accurate conclusion with respect to the health hazard. The cross-hatched portions indicate that within that range, dust concentrations could be in one of two. or perhaps even three, categories, actual hazard classification depending on the percentage of free silica. If. as an example, a cleaning room sample was 1.5-mg M'. thejobcould be marginally safe, as the safe range runs from 0.00- to 1.90mg M . and the marginal range runs from 0.95- to 3.70-mg M\ The sample could also be marginally hazardous, as that range is 1.35-mg M' and above, so a strict classification would not be possible. However, if the respirable dust level in the cleaning room is less than 0.95-mg V.`. we would not anticipate a problem, and would anticipate a problem at greater than 3.70mg MJ. Further explanation of this method of determining hazard class may be by another example. Suppose a respirable mass sample was collected on a small pouring ladle reliner operator in the melting department for 7 hr or 756 liters and the filter gained 1.588 mg. From Fig. 2 one would expect about a 559o chance of having a problem in the melting department of all foundries. Looking further, a steel foundry would expect an 839b chance of a problem in this operation. The respirable mass (1.588 mg x 1000-L.' M' 756L = 2.10 mg M3) of 2.10 mg' M1 can be used with Figs. 7 and 8 to confirm the existence of a problem. Using Fig. 7 for the melting department shows 2.10 mg in the marginally hazardous area well above the safe and marginal means. Using Fig. 8 for small ladle lining shows the sample in the marginal area well above the marginal means. Without a free silica determination this sample would be considered hazardous. Fig. 7. Hazard classification guesslimation chart tor general work area. AFS Transactions 19 SlAU. U9U LIM* tt.m% A.r.i.) filtrp ) jw , 'si i. r.:. C^m> 'MO MLU* Cfnu-^H fS.w* A.r.z.) rrr mji *.r.:.) 'HAirre.r cr-"*r--i i .: ot *.r.r.: :: d r* oft*. r iclsp .ciU'a*rc (c.s?4 4rTAJC CRUDES '..jh *.r.j.> ywc cruder IAS3 CB! 'C 3RL7 -. ^ i.rj 1* ' F353JK 1 l *___ V/77S///M ES I- E2 B V7XMSmA Lsfa l> ^S-WSI 4/*' hull CiMliriNtlM CwtltlMtlW Ctaun far Sat Spcifie tori Station Fig. 8. Hazard classification guesstlmatlon chart tor toma specific workstations. If the filter had weighed 0.529 mgthe respirable mass of 0.70 mg M1 would from Figs. 7 and 8 be considered safe. To test our theory of guesstimating the hazard class, it was tried on 69 'virgin' samples - those not included in the original data About 85rr was established accuracy in getting the samples into the correct category, so the method works with a good degree of accuracy The samples the authors missed on. in general, had an unusual percentage of quartz This shows that a free silica determination is required for absolute certainty in hazard classification. As a rule of thumb, the authors feel that respirable silica dust concentrations below I mg M' would not constitute a health hazard, and concentrations above 2 mg M! are likely to be hazardous The cost of setting up a lab to do x-ray diffraction analysis is substantial (S40.000 for the x-ray alone). It should be more economical, without too much sacrifice in accuracs. for a company or group of smaller companies to purchase two sampling pumps and chargers, a few cyclones, tubing, filters, etc. (S 1.000); an accurate balance (S2.000): and proceed to sample and use the Hazard Classification Guesstimationi HCC) ^presented in this paper. The HCC' would have to be supplemented by an initial determination of quartz percentages to see if they fall within the ranges found in our data, and then an occasional silica analysis to see if any change is noted due to change of type of sand, new molding or casting procedures or other process changes. It should be borne in mind that sand composition will vary in different localities, and the type ol foundry and particular process will also have a bearing on the respirable portion and free silica content ol the sample The sampling equipment, balance and related equipment cost translates into about 60 samples run for quartz. The HCG is a closely approximate way of checking ievets to detect changes, at an expense that is not overwhelming. Acknowledgements We wish to express our appreciation to Milan Racic for supplying data from samples run at the Salt Lake OSHA laboratory. Also to B. Chepil for establishing the computer data bank and typing the manuscript. References 1. N. A. Talvitie and L W. Brewer. `X-Ray Diffraction Analysis of Industrial Dusl~. American Industrial Hygiene Association Jour nal. Vol. 23. p. 214-221 (May-June. 1962). 2. J. Leroux. A.B.C. Davey and A. Paillard. "Proposed Standard Methodology for the Evaluation of Silicosis Hazards*. American Industrial Hygiene Association Journal. Vol. 34. p. 409-417 (Sepi. 1973). 3. N. A. Talvitie. `Determination of Free Silica: Gravimetric and Spectrophotometric Procedures. Applicable to Air-Borne and Settled Dust'. American industrial Hygiene Association Journal. Vol. 25. p. 169-178. (March-April. 1964). 4. N A. Talvme and F. Hyslop. "Colormetric Determination of Siliceous Atmospheric Contaminants*. American Industrial Hygiene Association Journal. Vol. 23. p. 214-221 (May-June. 1962). 5. D. G. Taylor. M. Nenadic and J. V. Crable. "Infrared Spectra for Mineral Identification'. American Industrial Hygiene Association Journal. Vol. 31. p. 100-108 (Jan-Feb 1970). 6 H. E. Ayer. "The Proposed ACG1H Respirable Mass Limit For Quartz: Review and Evaluation*. American Industrial Hygiene Association Journal. Vol. 30. p. 117-125 (March-April. 1969). 7 C J. Williams and R. E. Hawley. "An Industrial Hazard: Silica Dust". American Laboratory. Vol. 7. No. 7. p. 17-27 (July. 19751. K Criteria (or a Recommended Standard: Occupational Exposure to Crystalline Silica: U.S. Department of Health. Education and Welfare. Public Health Service. Center for Disease Control. National Institute for Occupational Safety and Health. HEW Publication No. (NIOSH) 75-120. 9 B N A. (July 12. 1972) 10 The Target Health Hazards. United States Depanment of Labor. Occupational Safety and Health Administration (1972). 11 Federal Register. (Thursdav-June 27, 1974). Vol. 39. No. 125.. Part II. Washington D C.. Department of Labor. Occupational Safety and Health Administration. Occupational Safety and Health Standards 20 AFS Transactions TRANSACTIONS of the AMERICAN FOUNDRYMEN'S SOCIETY Proceedings of the Eighty-first Annual Meeting, April 25-29,1977 VOLUME 85 1977 AMERICAN FOUNDRYMEN'S SOCIETY GOLF AND WOLF ROADS, DES PLAINES, IL 60016 A New Method for Monitoring Silicosis AFS RESEARCH K. A. Siegesmund, Dept of Anatomy Medical College of Wisconsin A. Funahashi Pulmonary Disease Sec. Medical Service Wood Veterans Administration Center and Dept of Medicine Medical College of Wisconsin K. Pintar. Laboratory Service Wood Veterans Administration Center and Dept of Pathology Medical College of Wisconsin Milwaukee. Wisconsin ABSTRACT Current methods for monitoring the development of silicosis after high levels of exposure to silica-containing dusts are unsatisfactory for the following reasons: 1) They do not detect silicosis until late in the course of the disease. 2) They are not always reliable, as for example, when there is a discrepancy between x-ray and pulmonary function tests. 3) Subjective judgements often are involved in the in terpretation of x-rays with differences of opinion between radiologists. 4) Current methods are expensive, time-consuming and, in the case of x-ray, potentially dangerous. The studies presented in this report describe a simple and accurate technique for determining the amount of silicon a worker has been exposed to presently or in the past. The technique is based on the use of one of the newest tools of * medical science -- scanning electron microscopy and energydispersive x-ray analysis. Introduction Energy-dispersive x-ray analysis (EDXA) (Fig. 1 and 2) is an analytical technique which permits simultaneous multielemental analysis of all elements above atomic number 8 while the object is being examined in the scanning electron microscope (SEM). The authors have used this technique to study lung tissue from a case of interstitial Fibrosis in which numerous electron-dense materials, observed by conventional transmission electron microscopy, were identified by EDXA and SEM as containing iron (Fe). nickel (Ni). chromium (Cr) and cobalt (Co).1 The authors have also studied silicosis with this technique and established the levels of silicon (Si) in lung tissue, both in normal and silocotics.2 3T4he usefulness of this method was also demonstrated on lung tissue where con ventional diagnostic criteria failed to establish a diagnosis of silocosis.' Conventional methods of detecting Si usually employ ashing techniques which not only require a relatively large amount of tissue but also can only be used to evaluate one element at a time. The technique which we are developing for the evaluation of silica exposure involves SEM and EDXA examination of 2-3 drops of blood. The technique is based on the fact that Si has been found in organs other than lung in silicotics. It was the authors' speculation that this was only possible if it arrived at these sites via the vascular system. Equipment and Procedures The authors' plan was to examine a group of control rats and a group which was given intratracheal injections of crystalline AFS Transactions 77-128 349 Fig. 1. A scanning electron microscope with s computer-based energy-dispersive i-ray analyzer. silica powder (Fig. 3). Samples of the rat blood were examined by placing a few drops on the surface of a carbon planchet (Fig. 4). After air drying the dried blood was placed in an SEM and examined for areas of thickest clotting. Three areas were then analyzed at 500X magnification for 200 sec each. The analyses were done using an Ortec l65eV resolution Si (Li) detector and a Tracor Northern NS-880 computer-based data handling system. All spectra were stored on magnetic tape for future reference. Spectral data were computer matched to reference spectra and elemental concentration ratios calculated. These con centration ratios were corrected for absorption, fluorescence and atomic number effects, assuming carbon as the background. Due to the inherent difficulties in determining the exact amount of material examined, the data was presented as a silicon to sulfur (Si/S) ratio. The concept of EDXA is based on the fact that x-rays are generated by the collision of the primary electron beam with the specimen. The wavelength, energy and the number of x-rays will be dependent on the elements present in the specimen and their abundance. Using a solid-state Si semiconductor detector, xrays emitted from the sample are collected and used to generate a small electrical signal whose charge is proportional to the energy of the incoming x-ray photon. This signal is electronically processed and displayed on a cathode ray screen (CRS). The x-axis of this spectrum represents x-ra&energy and the y-axis represents the abundance of every element above atomic number 8 in the area of the specimen being examined. These spectra can be stored on magnetic tapes. Fig. S shows a spectrum of a typical 200-sec analysis. Each peak seen on the CRS represents an element found in the tissue. The vertical dotted line (KL marker) is placed over the peak to be identified and the element symbol read at the lower left of the screen. The peak identified in Fig. 3 is Si of atomic number 14. Such an analysis can then reveal more than 80 elements simultaneously and in a matter of minutes. Fig. 2. Close-up view of computer-based analyzer with magnetic tape for spectra storage. AFS Transactions 5 Fig. 3. Scanning electron micrograph of the eillca duet used In the animal experiments. (X1000) Fig. 4. A one-inch stub of spectroscopically pure carbon con taining a thin section of lung tissue. The stub containing either a section of lung tissue or a tew drops of dried blood cen then be analyzed by energy-dispersive x-ray analysis. Fig. 5. View of screen of cathode ray tube showing peaks of Individual elements In lung tissue subjected to EOXA. The peak on the left shows the silicon level. Results The results of our animal studies reveal that after one injection the blood Si levels gradually increased and reached a peak after one week (Fig. 6). The blood Si level in these animals was three times that of the control (p <0.05). The Si level remained elevated for at least three weeks after the injection. When multiple injections of the same dose were given, at oneweek intervals, there was a progressive rise in the Si level (Fig. 7), reaching a maximum point after four injections. The total Si count after four injections was 10 times that of the control (P <0.01) The observations suggest that silica introduced transtracheallv into the lung reaches the bloodstream within a week and remains in the vascular system more than three weeks Studies are now in progress to determine the length of time that Si levels remain elevated after initial exposure. An attempt will also be made to establish the level of Si in blood which AFS Transactions Fig. 6. Blood silicon levels In rats after one Injection of silica dusts. 351 t 1 't i i/; NUMBER Of INJECTIONS Fig. 7. Blood silicon levels In rat* after multiple Injection* of silica dusts. would be considered to be toxic. In other words what level of Si would be considered as follows: 1) Normal 2) Elevated 3) Dangerous but not likely to cause disability 4) Toxic and coexistant with silicosis. To evaluate the results, the final phase of the study will be to determine Si levels in anonymous workers who have been exposed to silica dust. The importance of a simple blood test to industry would be its value in monitoring silica exposure. An employee or a future employee could be monitored for Si levels, the values reflecting not simple silica exposure, but actual silica levels in the lung Any worker with dangerous levels of Si in the blood could be removed from subsequent exposure before the levels become toxic. Such a test, unlike conventional methods now in use. would be simple, reliable and safe. References 1. K. A. Kiegesmund. A. Funahashi. K. Pintar. Identification of Metals in Lung from a Patient with Interstitial Pneumonia. Arch Environ Health 28, p 345-349 (1974). 2. A. Funahashi, 1C. Pintar, K. A. Siegesmund. Identification of Foreign Material in Lung by EDXA. Arch Environ Health 30, p 285-289 (1975). 3. K. Pintar, A. Funahashi. K. A. Siegesmund, A Diffuse Form of Pulmonary Silicosis in Foundry Workers. Arch of Path and Lab Med 100, p 537-538 (1976). 352 AFS Transactions 1 1 i r TRANSACTIONS of the AMERICAN FOUNDRYMEN'S SOCIETY Proceedings of the Eighty-third Annual Meeting, April 30-May 4, 1979 VOLUME 87 1979 AMERICAN FOUNDRYMEN'S SOCIETY GOLF AND WOLF ROADS, DES PLAINES, IL 60016 Description of a New Study of Occupational Health Hazard Control Technology for the Foundry Industry R. C. Scholz. Manager of Industrial Hygiene Programs Environmental Research Center Rexnord Incorporated Milwaukee, Wisconsin Introduction For years foundrvmen have been reducing or. in some cases, eliminating workplace hazards using their own ingenuity as well as approaches described in the industrial ventilation manual of the American Conference of Governmental Industrial Hygienists, and the Foundry Environmental Control series of the American Foundrymen's Society.10 Very little documenta tion exists, however, concerning the effectiveness with which these methods protect foundrymen from exposure. A lack of documentation limns the use of available methods and tends to hide problems for which adequate solutions have not been found and which should be the subject of research and development programs. It was to fill these information gaps as well as to provide a ready source of information concerning foundry environmental control technology that the National Institute for Occupational Safety and Health (NIOSH) under took. in 1976. a comprehensive study of the foundry industry using the Environmental Research Center of Rexnord Inc. (then the Environmental Sciences Division of Envirex Inc.) as their representative. The study was performed primarily through studies of the effectiveness of existing control measures and was conducted in twenty-four iron, steel, copper-base and aluminum foundries around the country. The report of this study is now available from NIOSH.1 Priorities for Study It was apparent at the outset that a study conducted in twentyfour foundries would not be able to evaluate solutions to all foundry hazards, thus criteria were established to assure that available solutions for the most pressing problems facing the foundry industry were investigated. The principal factors used to set priorities were the severity of the hazard, the potential for overexposure, the number of workers affected, and the use of control methods in existing foundry operations. Highest priori ty was placed on methods to control air contaminants, since these posed a severe potential health hazard. Many air contaminant control measures were known to exist although overexposure of workers still continues. Less attention was paid to noise control, because noise is less of a hazard than air contaminants and control technology for noise has only been applied to a limited extent in foundries. Heat stress control in foundries is achieved for the most part through acclimttizauon programs for workers and through ventilation of hot processes and so this area became an adjunct of the air contaminant control study. Methods This study was performed on a completely voluntary basis and recommendations for candidate foundries were elicited from a foundry trade association, foundry professionals, and the literature. The foundries selected included captive and job shops involving large and small production of very small to very large castings, and -a wide variety of molding and coremaking processes. Contrary to what one might suspect, effective control technology was not found to be limited to high production, captive foundries or to foundries with the greatest available resources. The principal resource which distinguished foundries with good health hazard control programs from those without, was an awareness and desire on the part of management and labor to provide a safe and healthy work environment. Foundries who eliminated hazards were those who had the determination to explore various alternatives, to work patiently toward reducing worker objections to new practices, to minimize process disruptions, and to maintain levels of system performance through careful operation and maintenance It was desired to use as much of the foundry's own data as possible to verify the effective performance of a particular control method. Unfortunately, very little data has been taken after control systems were installed. The majority of foundry sampling data involved measurements taken to identify problem areas. Consequently, the great majority of the sampling data presented in the NIOSH report was taken by the study team Foundry Hazards The following are hazards that current literature indicates to be of high hazard potential, as well as some of their major sources in foundries. Free Crystalline Silica This hazard, primarily associated with Tine respirable quartz particles, is ubiquitous in sand cast foundries and is found particularly in operations which transport or process dry sand after shakeout. In ferrous foundries the burn-on of sand into the casting caused by molten metal penetration into mold and core materials creates another substantial problem during manual abrasive cleaning operations. At high temperatures, quartz transforms to cristobalite which is more hazardous still. Cristobalite is present as a significant hazard during furnace and ladle relining. Metal Dust and Fume Common alloy metals of hygienic significance found in casting operations include lead, copper, nickel, chrome, zinc, magnesium, manganese, iron and aluminum. Lead stands out as a severe acute hazard and nickel has recently become suspect as a carcinogen. The fume hazard of each metal during melting and pouring operations as well as welding and arc-air gouging depends upon its relative toxicity, percentage used in the alloy, and alloy melting and boiling temperatures. Metal dust is usually associated with abrasive grinding operations. Coal Tar Pitch Volatiles Organic mold and core materials undergo destructive distilla tion after molds are poured producing various compounds, including benzo-(a)-pyrene. a known carcinogen. The question has ansen as to whether these compounds are the cause for the elevated lung cancer incidence in foundry workers. Research is needed to establish the potential hazard during the casting process. Cases and Vapors Many of the gaseous hazards are the result of thermal transformations and breakdown of binders and additives during the process of producing molds and cores using hot methods, and during thermal decomposition during casting. Examples are: I) Carbon monoxide from thermal decomposition of any AFS Transactions 79-78 601 organic material, including combustion of coke used as a fuel in cupolas 2) Acrolein from thermal decomposition of glycerin in many core oils during core baking and casting. 3) Methylene biphenyl di-isocya nates fMDI) dunng ther mal decomposition during casting of urethane polymers used in nobake cores and molds. 4) Ammonia from thermal breakdown when intense heat is used to accelerate the curing of resinous binders con taining nitrogen compounds and during mold decom position of furan and phenolic hot box (shell) molds and cores. 5) Formaldehyde, found in all furan resin mixtures; phenol, from phenolic resins; and furfuryl alcohol, used in the production of furan resins and in some modified phenolic resins, are emitted from hot box coremaking as well as dunng casting. Other gaseous hazards include amines (catalysts for organic binder systems), hydrogen sulfide (water quenching of sulfurous slag materials at cupola slag spouts) and sulfur dioxide (burning of high sulfur coke in cupolas). Noise Noise is hazardous because it can cause hearing damage and pose a threat to life and limb by the worker not being able to hear a warning signal. Noise within foundries has been increasing steadily over the years as a result of mechanization and high production. Principal noise sources include loud furnaces (gas fired crucible, electric arc), shakeout, casting transport, han dling and manual cleaning with abrasive tools. Conclusions of the Study The following are a few of the major conclusions of the study. Green Sand Systems Control of green sand systems requires a combined program of effective ventilation and effective housekeeping. Many sand system ventilation methods, in use in foundries for many years, were found to be effective in controlling dust exposure. An alternative to conventional dry sand transporting and process ing. the Schumacher process, effectively limited dust emissions from return sand by mixing prepared sand with it. thus reducing me amount of ventilation required. Substitute molding sands did not eliminate silica from dust when silica sand was used for cores, or clay was used as a binder. The problem with shakeout hoods, particularly the sidedraft variety in use on shakeouts loaded by overhead crane, was that they were gradually demolished by the operation, permitting the flask handlers to be overexposed to respirable silica. When a large flask was unloaded onto the shakeout table by overhead crane, not all of the contents of the fiask always fell out; some mold materials were hung up in the fiask. The crane operator removed these materials bv ramming the flask against the shakeout hood. One foundry, realizing that work practices such as this will likely continue, but also fed up with annual replacement of hoods, constructed a structure mounted on the shakeout table itself which solved the problem. The modified shakeout with a shakeout hood behind it are shown in Fig. I from the NIOSH report The structure did not upset the vibration of the shakeout, but special retaining plates were needed to prevent the shakeout table from being displaced off of its springs when the structures were rammed. After one year the shakeout hood had still encountered no abuse. Melting and Casting Charge bucket filling was found to be a dusty operation. Much of the dust produced was induced in strong drafts of air toward the melting area because of a high volume of exhaust and lack of 602 Fig. 1. Structure mounted on shakeout to protect aidedratt hood from damage (reprinted from NIOSH Technology Assess ment). Fig. 2. Complete tume capture during tapping ol an induction furnace through the use of furnace and ladle mounted capture hoods (reprinted from NIOSH Technology Assessment). makeup air in most foundries. Ventilation methods and isolation of workers in booths controlled exposure to metal fume, heat stress and. in some cases, noise, during melting, hot metal transfer, and pouring operations, as well as during ductile metal treatment. Lead fume is receiving a considerable amount of attention at present because OSHA has lowered the permissible exposure level (PEL) for lead from 200 Mg/m' down to fifty. The results obtained during studies in two copper-base foundries alloying with lead have shown that with careful design of localized ventilation in conjunction with administrative control of work practices, it was possible to reduce the exposure level of workers below the 200 ug m' level. Efforts to further reduce exposure levels will require resolving certain problems which limit the effectiveness of ventilation methods. The furnaces evaluated during the two case histories of nonferrous operations were tilting induction furnaces, used extensively for copper-base alloy melting. These furnaces were amenable to control using commercially available ventilation hoods. Such hoods have been found to provide adequate control during the charging and meltdown cycles, but were not effective by themselves in capturing fume during tapping into ladles because of interferences from ladle support mechanisms. In the presence of interferences, fume control was still achievable if a ladle ventilation hood were used in conjunction with the furnace hood. Such an arrangement is shown in Fig. 2 from the NIOSH AFS Transactions Fig. 3. Fume control during metal pouring using a mobile ladle mounted capture hood (reprinted from NIOSH Technology Assessment). report. This particular ladle hood was a commercially available mobile hood which can provide exhaust above the iadle during the entire ladle filling, slagging, hot metal transfer, and pouring operation (Fig. 3). Unfortunately, the transfer paths from furnaces to pouring lines in many nonferrous foundries are not direct and the use of this commercially available close-capture method, although still possible, is not at all straightforward. Use of the method in those cases could slow down the operation to the point of causing chilling of the metal, resulting in excessive scrap. The strong dependency of ventilation methods on foundry' layout is so critical that no nonferrous foundry should consider renovations or new foundry layout without providing proper provisions for ventilation control during hot metal transfer and mold pouring. Another cntical variable in the use of mobile ladle hoods is the need for quiescent air patterns in the foundry. Many foundries, because of high negative pressure, are beset by strong air drafts through doorways. The above mobile ladle hood does not function properly in the presence of strong drafts. Ventilation of mechanized pouring iines in ferrous foundries was accomplished with commercially available, as well as custom designed, sidedraft hoods. Control of mold decomposi tion products during mold cooling was simplified in such systems. On the other hand, effective smoke and fume control during open floor pouring operations, such as pallet lines, was much more difficult. One foundry developed its own powered conveyor system for rapidly moving molds from the pouring area to an isolated cooling area immediately after mold pouring. Ferrous Cleaning and Finishing Control of respirabie dust and fume in the breathing zones of all workers manually cleaning ferrous castings was not found during the study Two sources of dust posed special hazards for cleaning and finishing operations: dust created by grinding casting surfaces having imbedded sand, and loose dust in internal casting cavities remaining after precleaning. Besides manual cleaning and finishing operations, another silica dust hazard occurred during removal of sprues, gates, and risers using hammers. Control of silica dust is hampered because this is one of the hottest operations in the foundry, due to the fact that castings are often processed immediately after shakeout. Mancooler fans and high velocity fresh air ducts were used to prevent excessive heat stress on workers, and these methods disrupted the ability of ventilation hoods to capture dust before it entered the breathing zone. Because no methods were available to provide adequate ventilation for this process, engineering personnel from one AFS Transactions Fig.4. Cross section of wire mesh belt conveyor (reprinted from NIOSH Technology Assessment). foundry took it upon themselves to develop their own ventila tion technique, a downdraft mesh belt conveyor. An end view, cross-sectional sketch of the method is shown in Fig. 4. Sand and dust were drawn together through the conveyor: the dust was exhausted to a fabric collector and the sand fell onto a conveyor which transported it back into the sand system. This method prevented overexposure of foundry workers to Jree silica. The conveyor system, all custom designed, has the obvious look of ruggedness which one would expect from a system designed by individuals cognizant to the severe service imposed by the foundry environment. Molding and Coremaking Using Chemically Bonded Sand New chemical binding systems are becoming rapidly popular and the need exists to scrutinize these methods to ascertain proper ventilation requirements. One such coremakmg process which was evaluated during the study was phenolic urethane coremaking. The gassing of the cores with tnethytamme (TEA) ordimethylethylamine (DMEA) occurs in a sealed corebox and after the setting process the gases are purged from the core and exhausted through a sealed duct system. Two potential problems were found with this method which required the use of auxiliary ventilation to provide effective control. The first resulted because the gas purging cycle was established on the basis of removing sufficient gas to terminate the chemical setting process, not on the basis of removing all of the residual gas. Removing all of the gas would probably have required an excessively long purge cycle, detracting from the high produc tion capabilities of the core machine. Thus core machine operators and core finishers were subject to exposure from residual gases during core handling and processing. The second problem is related to the operation and maintenance of the core machine itself. Effective containment of gases requires proper sealing from parting line gaskets, blow seals, and stripper pm O-rings. Gas blow-by was also caused by excessive backpressure on these seals from excessive sand fines and moisture in the sand orfrom the air compressor. To prevent exposure to the catalytic gases from seal failures and also to reduce exposure to residual gases from completed cores, one foundry has employed a capture hood adjacent to the corebox. and another one above the core retrieval rack (Fig. 5). Distributed fresh air is utilized throughout the coremaking area to dilute escaping, residual gases. 603 Summary This description of the NlOiSH Toundry health hazard technology assessment study was presented to create an awareness of some of the ways that foundrymen are using to resolve worker hazards. The NIOSH report contains many case histories of methods which could have a broad base of application in foundries, in addition, there are a number of problems which were investigated for which effective solutions were not found. Manual chipping and grinding of ferrous castings was found to be incompletely controlled with existing methods. The conditions under which ventilation systems on floorstand grinders are capable of controlling dust are not well defined. Ladle relining creates hazards from quartz and cnstobalite which have defined control using available ventila tion methods. Metal fume control during the arc-air process is very worker-dependent, but exactly which operational procedures are critical has not been established. Noise solutions have been iimited to the use of enclosures in certain restricted cases and substitution of quiet components for noisy ones. Much research and development into health hazard control technology for foundries remains to be done. However, each time a foundry takes it upon itself to attempt a solution and then makes the results of that attempt, either positive or negative, available in the literature, the environmental control effort to provide a healthful work environment for all foundrymen comes closer and closer to fruition. References 1. Committee on Industrial Ventilation. "Industrial Ventilation: A Manual of Recommended Practices" (Lansing. Michigan: 1976). 2. Foundry Environmental Control, Volume I (Des Plaines. Illinois: American Foundrymen's Society. 1972). 3. NIOSH Contract No. 210-77-0009. "An Evaluation of Occupational Health Hazard Control Technology for the Foundry Industry." Fig. 5. Exhaust of cold box coremaking (reprinted frtyn NIOSH Technology Aaaessment). 604 AFS Transactions AFS RESEARCH An Examination of the Potential Free Silica Formation During the Grinding of Gray Iron W. B. Huelsen Vice-President, Environmental Affairs G. E. Mosher Industrial Hygienist G. L. Carter Manager, Frank S. Ryan Laboratory American Foundrvmen's Society Des Plaines, Illinois ABSTRACT Historically, quartz exposures in ferrous foundry cleaning rooms were not thought to be a problem. Recently, though, high levels of dust containing quartz have been found in these cleaning rooms despite many process changes aimed at lowering them. As a result, questions have been raised concerning the source of the quartz in the dust. There are potentially a number of sources for the quartz. The purpose of this investigation was to examine one potential source: the formation of quartz from oxidation of silicon (Si) in the casting or from the grinding wheel at the point of grinding. The contribution of the grinding wheels themselves to quartz levels was also determined. Two types of bar stock, a gray iron (2.54% Si) and an ingot iron (total impurities including Si 0.14%), were each ground using a silicon carbide wheel and an aluminum oxide wheel individually. Grinding was done in an unventilated enclosure designed to contain the dust generated. Respirable dust samples were taken in the enclosure while grinding. Analysis of the samples by x-ray diffraction showed that the amount of quartz in the respirable dust samples did not exceed the background levels found on blank filters that were analyzed by the same method. An additional test was performed using two gray iron gear blanks. One gear blank was cleaned in an airless abrasive blast, the other was in the as-cast condition taken directly from the shakeout. Analysis of the respirable dust samples taken indicated no presence of crystalline quartz above background levels in the collected dust. It is therefore concluded that the Si in the metal did not react with the oxygen in the atmosphere to a measurable extent. The absence of quartz above background levels on the filters also indicated that the grinding wheels did not contribute to quartz in the analyzed dust. Introduction in July. 1976 an ad hoc committee was formed by the American Foundrymen's Society to investigate the sources of quartz exposures in ferrous foundry cleaning rooms. Excessive exposures to free silica (its three principal mineral forms being alpha quartz, cristobalue and iridymue) can. if left unabated or untreated, cause an employee to develop the pneumoconiosis called silicosis. The development of this disease is a function of the duration of exposure, level of exposure to the dust, concentration of crystalline free silica in the dust, particle size of the dust and existing physiological conditions. Recent reports' as well as personal observations had indicated that quartz exposures in cleaning rooms were excessive despite many process changes meant to lower exposure. Such process changes as the application of nonsilica washes, nonsilica factng sands, airless abrasive blasting of castings prior to band chipping and grinding, and the increased use of local exhaust ventilation had limited effect on exposures. Gilliland2 in 1973 showed that sand grains were adhering to the surface of castings despite airless abrasive blasting. Later, private research comparing the quartz contents of dust generated from the grinding of castings which had been treated with an electrically charged 204C (400F) caustic soda bath to that of nontreated castings indicated that the quartz may be bound chemically, as well as mechanically, to the surface of the casting. When metal penetration was studied in 1977' it appeared that sand grain adherence to the casting surface was due to some type of physiochemical reaction. The effect of the reaction produces a senes of casting surface defects which are progressively harder to remove. These defects, in ascending order of difficulty of removal, are "rough surface." "sand burn-on." "sand burn-in" and "metal penetration " Each degree of severity involves some type and quantity of sand grain adherence to the casting surface. The presence of these sand grains indicated a potential source for the quartz found in ferrous foundry cleaning room dust samples. Airless abrasive blasting of castings both before and after rough grinding has been increasingly used in the industry for both cosmetic and functional purposes. The possibility was explored whether castings could be airless abrasive blasted in such a way that adherent and embedded sand grains could be completely removed before rough grinding. If this could be accomplished, it was felt that a major source of silica in cleaning room airborne dusts would be eliminated. To test this theory, two batches of identical castings were blasted for 3 min and 15 min. respectively, to simulate short and very long duration cycles. Each batch of castings was then hand ground in a "clean" room and airborne dust samples taken. Before each test, the "clean" room was vacuumed out and purged with clean air to remove any residual dust from previous AFS Transactions 79-93 707 Res,< i f ul> 1c Hus i (RHj Tot-il Imsi (TD) RD TD TD Tabl1y -Weight Percent fOuarti as a Function of Bliutlng Time Local ion IS :| himv Blast inn 3 Minute Blast me Concvini r u ion wt : ConcenTLV<*' t rat ion ui : TLV( ` - j^L . Ouirti ' Ouart z wc iirciihnv Zone (B4) SJ Are* Sample (A5)([; 5.P' 24.0 5.1 - 4.-3 1.1 2.0 1.59 7.3 2.5 9.5 4 m.O 8.6 3.: 1.92 7.3 * *5 1.92 As U; 21.0 <1.0 10.0 35.0 1.0 7.5 AS dll 20.0 <1.0 10.0 31.0 2.1 5.88 ^ TIV (Respirable Dusli * (10 mg/n^i -r (Ui I Quartz * 2l TI.V (Total Dust) - (30 mg/ia3> -r (Wi I Quartz 3; tests. The airflow in the room was also controlled to ap proximate conditions in a foundry (50 fpm). The dust samples were analyzed by x-ray diffraction for quartz and weight gain. The weight percent quartz in the dust was low to begin with in all cases, yet did not seem to be a function of the blasting time. The concentration of dust in the air. however, was less for castings blasted 15 min than for those with the 3 min cycle. This is probably due to the more complete removal of quartzcontaining material adhering to the casting surface which otherwise would have had to be removed by grinding. Unfor tunately. no data was recorded to determine this parameter. In all cases the calculated theoretical Threshold Limit Value (TLV) was violated (see Table 1). These results indicated that possibly some baseline level of quartz was being generated which could not be controlled through conventional production techniques. To explore this possibility and its source, the tests reported here were initiated. Silicon is a very reactive metal' and a constituent, to some extent, in most ferrous castings. The presence of Si raises the possibility that at the point of grinding the Si was reacting with the oxygen in the atmosphere to form free silica.4 Test Condition and Materials The experimental procedure was designed to specifically deter mine if the origin of respirable free silica was from the grinding wheel and or the ferrous metals being ground. To investigate these two possible sources, four sets of closely controlled grinding conditions were evaluated using: 11 a low Si content grinding wheel and low Si content metal: 2) a high Si content grinding wheel and a low- Si content metal; 3) a low Si content grinding wheel and a high Si content metal: and 4) a high Si content wheel and a high Si content metal. In an attempt to isolate the source of quartz, multiple respirable dust samples were taken during each grinding condition. Since respirable dust (that dust which has a panicle diameter less than 10 micrometers but greater than 0.1 micrometers) is of primary concern from a physiological standpoint (it can reach the lung), sampling equipment capable of removing the coarser fraction of panicles present (those greater than 10 micrometers in diameter) and collecting the respirable fraction was used. 708 Fig. 1. Air sampling train. A dust sample which does not size fractionate the particulate collected is called a total dust sample. The air sampling train (Fig. 1) consisted of a 10 mm Dorr Oliver cyclone as a prefilter to remove the nonrespirable paniculate, followed by a 5 micron pore size PVC filter 37 mm in diameter. A battery operated diaphragm pump with pulsation dampener was used to draw the air through the sampling train at a rate of 1.8 lit /min. This is the designed flow rate for this particular size selective prefilter to maintain optimum separa tion of the respirable from the nonrespirable paniculate. An aluminum oxide wheel was used as the low Si content grinding wheel. A silicon carbide wheel was used to represent a high Si content wheel. Complete analyses of these two wheels is provided inTable2. Both wheels used were I4x2-l/2x 1-1/4 in. with a grit size of 16. The grinding machine was a 3 horsepower double wheel stand grinder with a spindle speed of 1.800 revolutions per minute (RPM). A grinding wheel speed of 6.795 surface feet per minute (SFPM) was obtained using these wheels. A higher wheel speed would have increased the metal removal rate and the amount of dust generated but would not have affected the chemical composition of the dust. To satisfy the low Si metal condition of the test, ingot iron was chosen. The ingot iron was in the form of rough sheared stock AFS Transactions Table X Chemical Anelyila el Gf*dti*g Wheels, *?ro,,,d#dhv ManutKturvra _ Silicon Carbide Grinding Wheel Material Content Silicon Carbide (SiC) Free Silicon (Si) Free Silica (SiO^l Free Carbon (C) 98.06 0.63 0.57 0.25 Iron (Fe) Aluminum (Al) 0.16 0.23 Calcium (Ca) Magnesia (Mg) 0.05 0.05 100.OZ Aluminum Oxide Grinding Wheel Aluminum Oxide (AljOj) Titania (TiOj) Silica Zirconia (ZrO^; iron Oxide (FcjOj) Manganese Oxide (MnO,) Calcium Oxide (CaO) Magnesia (MgO) Alkalis (Soda + Potash) 95.27 2.67 1.05 * 0.35 0.15 0.11 0.05 0.31 0.04 100.oz ; TableX Chemical Analysis of, Bat Stock , Iron Stock Iron All Other Elements 99.86Z 0.14Z Continuous Cast Grav Iron Iron Carbon (Cl Silicon (Si) Manganese (Mn) Sulfur (Si 93.4Z 3.24 2.54 0.759 0.048 Gear Blank Iron (Fel Carbon (C) Silicon (Si) Manganese (Mn) Sulfur (S) Phosphorus (P) 94.07Z 3.20 1.86 0.70 0.12 0.05 *This value is for silica present in a chemically combined form, not free silica. It is in the form of a glassy slag within the grains of the fused alumina. approximated 2-1 2 x 2-1 2 x 3/8 in. in size. A continuous cast gray iron bar of 2-1 2 in diameter was used as the high Si metal (Fig. 2). This gray iron casting was chosen because of the absence of silica-containing materials used in the continuous casting process Chemical analysis of these two metais is provided in Table 3. All grinding and air sampling for these tests was conducted in an enclosure with a volume of 28.5 cubic feet (Fig. 3). This enclosure contained the grinder, a pneumatically operated device for forcing the metal coupons against the wheel at a uniform pressure, and the air sampling train. Access doors were provided for cleaning, wheel changes, servicing of air samples, etc. Air samples were collected during all previously enumerated test conditions. The flowrate was set using a Brooks precision rotometer which had been calibrated with a soap film flowmeter before and after the tests. The flowrate was checked after the first 7 min of each test then at 15 min intervals. The cyclones were dis assembled after every test and cleaned in an ultrasonic bath containing a cleaning detergent. They were then rinsed with AFS Transactions Fig. 2. Rough sheared Ingot ttock flow SI) and continuous cast bar stock (high SI) tor test specimens. isopropyl alcohol and allowed to air dry. All of the air samples were analyzed by x-ray diffraction for quartz and cnsiobalite content. Two sampling trains were placed near the rear of the enclosure approximately 12 in. from the exhaust port of the grinder. A grinding time of 45 min was determined to be adequate to collect an air sample with a sufficient quantity of dust to be analyzed accurately by x-ray diffraction. During each grinding condition test, metal was fed into the grinding wheel by pressure applied with a pneumatic pressure feed device (Fig. 4). Air pressure to the 2 in. pneumaticcylinder on the pressure feed device was supplied by a I horsepower portable compressor. The low Si metal was fed into the wheel at a pressure of 20 psi, the high Si metal at a pressure of 45 psi. The 709 Table 4. T*> Pinnwlm 7s i Numt>6 r Type Wheel Type Metal Ground Air Pressure to feed cylinder (PSl; Grinding Time (minutes; Loss of metal weight during test (oz; Loss of wheel weight during test (oz; Ambient Temperature (outside enclosure)(F; Temoerature rise in enclosure (F; 2 Cross section of metal area against area (in ) 1 Al 11 20 45 2 5 66 35 2.18 2 SIC II 20 45 2 2 64 32 2.18 3 Al Cl 45 45 7 3 70 70 4.91 4 SIC Ci 45 45 57 33 69 72 4.91 Gear Blank Gear Blank (as cast; (shot bias SIC SIC Cl Cl 40 40 15,30 15,30 26 21 -. 73 39 2 73 44 -- Al - Aluminum Oxide SIC - Silicon Carbide II - Ingot Iron Cl - Continuous Cast Cl - Cray Iron Iron Fig. 3. Enclosed cabinet (or grinding and air sampling tests. 710 difference in pressure was to compensate for the difference in cross sectional area of the low and high Si metals against the grinding wheel. These pressures were also chosen because they were the minimum amounts needed to create a continuous stream of glowing swarf. This is a condition commonly created when castings are ground in a ferrous foundry cleaning room. For a detailed listing of the testing parameters, consult Table 4. Before the test began, all the bar stock used was cleaned with a degreasing solvent to remove any surface coatings which might be present and thus affect air sampling results. The bar stock was also airless abrasive blasted to remove any oxides. The enclosure was brushed and vacuumed to remove any residual materials between tests. Both the grinding wheel and the metal to be ground were weighed before and after each test to determine material loss. Grinding wheels were dressed before the start of each test and at 15 min intervals thereafter. During the dressing operation, the doors of the enclosure were opened and the sampling pumps turned off. The temperature inside the enclosure was monitored during the test in order to determine if it might prove a factor in any reactions that might occur. The parameters of the tests taken using the gear blanks (Fig. 5) is also listed in Tables 3-S. Three air samples were taken to determine background levels of dust for comparison purposes. During these tests the grinder was off and all equipment surrounding the test enclosure was turned off. Background samples were taken both outside and inside the grinding enclosure at the same location as the air samples taken during the grinding test. Results Table 5 presents the analytical results from these tests. The amount of dust collected on the filters was anywhere from 38 to' 350 times the amount needed for accurate analysis by x-ray diffraction. The amount of quartz collected on the filters was within the range of quartz present on the blank filters. As a result, it was determined that no measurable amount of quartz is being generated by a chemical reaction between the Si in the metal and atmosphere during grinding. In addition, the wheels AFS Transactions Type of **et*l Feed Stock WHEEL TYPE" Aluninum Oxide Sanple 1 Sample 2 Silicon Carbide Sample 1 Sample 2 Sample 3 T*bl 5. Quantities ol Dust Collected (mm) -------- ---------- ` Ingot Iron ~ Cont inuous Cist Cray .Iron 3.80 3.75 4.40 4.94 34.56 35.18 34.08 32.02 30.68 Background Levels Within enclosure 40.010 ng Outside enclosure 0.010 mg Coir Bl"k Gnv Iron Shot Blast Gear Blink Crav Iron Not Snot Blast 10.36 * 25.1 3 ** 10.55 * 20.74** Each of the samples were analyzed for quartz content. In all cases the quartz content did not exceed the amount found on the blank filters submitted for analysis. 16 tillers were submitted for analysis (including three background samples! along with 6 blank filters. * 15 minute air sample. **30 minute air sample. themselves did not generate any measurable amount of free silica. Discussion The results of these tests indicate that further investigation should be conducted to determine the source of high silica dust levels commonly found in ferrous foundry cleaning room air samples. If indeed the casting surface is the source of the free silica, then tests similar to these m concept should be performed. A logical next step would be to conduct other tests using a cast plate instead of bar stock and a surface grinder instead of a stand grinder. Shallow cuts with a surface grinder in an enclosure on plates cast under varying conditions would demonstrate wnether the generation of silica dust is a surface phenomenon. The tests herein reported were not designed to investigate this theory. Different molding media and mold coatings should also be used. Another theory is that there are chemical and physical reactions occurring at the mold-metal interface at which various forms of iron silica-silicate materials are formed. Some of these materials may create or generate free silica when mechanical energy is applied. Visual examination and subjective judgments are normally applied to determine when a casting surface is clean. Examina tion of casting surfaces both by low power magnification and copper plating techniques reveals the gradual diminishing of embedded silica with increased blast cleaning time. Unfor tunately. these methods have not evolved to the point of quantifying the amount of embedded silica on the surface to determine if. upon being ground or chipped, the resulting exposure would be within permissible limits. These techniques, at this time, do not lend themselves to production use efficiently. A measurement technique which lends itself to production use. giving both accurate results and a correlation with expected AFS Transactions Fig. 5. Gear blank test specimens. exposure, should be developed. A problem to be overcome with the use of this type of measurement would be the nonuniform distribution of embedded silica in the casting surface. Since there appears to be little published information on the surface of castings specifically concerning the physical and chemical state of any silica present, a microscopic examination of surface defects pertaining to metal penetration should be done. Such a study could also determine the thickness of metal penetration. With such information, judgments regarding the ability of airless abrasive shot blasting to remove them could be made. Examination of the surface of "new" versus "used" shot to see if silica is adhering to the shot surface may be of some value. This silica may redeposit on the casting surface by electrostatic attraction during airless abrasive shot blasting only to be removed during subsequent mechanical surface treatment, i.e.. 711 grinding, chipping, etc. A related theory would be that during abrasive blasting some sand grains are being blasted on and mechanically bonded to the surface of the casting due to the impaction of the shot. As the surface is ground, these particles of sand are liberated, causing -exposure. An analysis of grinding dust itself by scanning electron microscopy or some other appropriate analytical method or device would give an insight into the source of the silica. Since it was the tests conducted some years ago on castings which were treated to a hot. electrically charged caustic soda bath which seemed to indicate some chemical (versus mechanical) adherence, perhaps these tests should be repeated under more closely controlled conditions, particularly since these tests were of unknown reliability with no hard data available. There are a number of theories regarding the formation of silica on the surface of the casting with ensuing free silica exposures when those surfaces are ground. The theory that was tested during these experiments was that the Si in the metal or in the abrasive media was reacting with the atmosphere to form free silica. Conclusion .. The results of these tests indicate that the reaction of the Si in the metal and oxygen in the atmosphere at the point of grinding does not occur to any measurable extent. Acknowledgments We would like to thank the Norton Company. Worcester. M A for the grinding wheels used in this studs: Wells Manufacturing. Skokie. IL for the bar stock: and Wagner Castings. Decatur. IL for the chemical analysis of the bar stock. References 1. R. E. Zimmerman and J. M. Barry. "Determining Crystalline Silica Compliance Using Respirable Mass." AFS Transactions, vol 84, p 15 (1976). 2. R. C. Gilliland. "Silica Sand Transformation at the Mold-Metal Interface Dunng and After Solidification-A Preliminary Report," AFS Transactions," vol 82. p 301 (1974). 3. A. B. Draper and J. L. Gamdhar. "Metal Penetration - A Critical Literature Review." AFS Research Reports, p 163 (1977) 4. T. D. Murphy. "Silica and Silicon." Industrial Minerals and Rocks. S. J. Lefond. ed. (4th ed.: American Institute of Mining. Metallurgical and Petroleum Engineers. Inc.. 197}), p 1043-1060. 712 AFS Transactions * Foundry Health Ik Safety Guide Series 1. Procedures of Occupational Safety and Health Review Commission 2. Silica 3. Carbon Monoxide 4. Noise 5. Foundry Medical Program 6. Makeup Air 7. Beryllium 8. Iron Oxide Fume 9. Urea-Formaldehyde Resins 10. Hot Box Resins 11. Nobake Resins 12. Phenolic Resins 13. Epoxy Resins 14. Inert Nuisance Particulates 15. Tellurium 16. Aluminum and Aluminum Oxide 17. Magnesium and Magnesium Oxide 18. Nickel 19. Sulfur Dioxide 20. Acrolein 21. Zinc Oxide 22. Urethane Resins 23. Lead 24. Copper 25. Chromium and its Compounds 26. Calcium Carbide (carbide) A Senes Published by the American Foundrymen s Society NUMBER 2 Foundry Health & Safety % ** iOCf" SILICA Free silica or quartz (SiO:) is a major constituent of foundry sand and can be presented in high concentrations in silica flour and in some silica mold or core washes. Tridymite and cristohahtc are also crystalline forms of silica; these can be generated at the mold metal interface as a result of the high temperature transformation of quartz. Mans foundry operations result in employe exposure to fine dust generated as a result of mechanical or thermal fracture of sand particles. The main sources of foundry exposure involve (I) the handling or mulling of new sand or dry sand from shakeout. (2) use of silica-containim: parting compounds or mold washes, (3) shakeout and (4) casting cleaning. Other sources of silica dust exposure include general maintenance and cleaning and furnace and ladle repair operations. OSHA EXPOSURE LIMITS are calculated from the following formulas Substance mppcf mg/m3 crystalline quartz (respirable) crystalline quartz (total dust) (in mppcf) 250 * SiO: + 5 (in mg/m') (in mg/m3) 10 mg m' ** '7 SiO: -F 2 30 mu m3 rl SiO.. + 2 cristobalite, tridymite and silica flour (intended) -- use I 2 the value calculated from the count or mass formulas for quartz. mppcf mg m' * ** = millions ofpanicles per cubic fool ofair, based on im/nnger samp/e\ counted In light-field techniques = milligrams per cubic meter of air percentage of crystalline silica in the formula is the amount determined from airborne samples except in those instances in which other methods have been shown to the applicable. both concentration and percent quart: for the application of thr limit are to he determined from the fraction passing a size selector having, in brief the ahilti v to retain all particles greater than 10 microns andpassing 90 percent <: the particles 2 microns or less in diameter. HAZARD I he degree of hazard depends on silica content, concentration and si/e of the a v>rne dust, as 'sell as the length of exposure. Silicosis (occasionally complicated by tub-.. Josis) is the occupational disease associated with excessive exposure. Heavy exposure' produced symptoms in less than one year after initial exposure; many years, howevv ;re generally ieqHired to produce symptons. CONTROL PROCEDURES Process -- Substitution of other materials, such as nonsilica mold pariingcompounds. molding aggregates and abrasive grits, should be considered first. All sources of dust exposure should be enclosed as much as possible and exhaust ventilated to a suitable collector. Some dust sources, such as abrasive blasting operations, mullers. screens and some shakeouts, can be complete^ enclosed. Only partial enclosures, however, are possible at other operations, such as chipping and grinding operations and most shakeouts. The poorer the enclosure, the greater the exhaust capacity required to provide positive control. Local exhaust ventilation systems should be designed by an experienced ventilation engineer in accordance with design cntria presented in, industrial Ventilation - a Manual of Recommended Practice, available from the Committee on Industrial Ventilation, P. O. Box 453, Lansing, MI 48902: American National Standard Z9.21971. Fundamentals Governing the Design and Operation of Local Exhaust Systems available from the American National Standards institute, Inc., 1430 Broadway. New York. NY 100IX and the A FS Foundry Environmental Control Manual. Volume l. Housekeeping -- Settled silica-containing dust is an important source of exposures in most foundries. Settled dust is easily reentrained by slight vibration or air currents. Settled dust should be periodically removed, using vacuum methods, from all overhead struct tires, equipment and floors. Vacuum cleaning will be required at infrequent intervals if all major sources of dust are properly controlled, using local exhaust ventilation. Personal Protection -- Respiratory protection should be selected from those approved by the National Institute for Occupational Safety and Health for protection against pneumoconiosisproducing dusts. Medical Program -- Employes who have been or who are exposed to.silica dust should he under medical supervision. This is discussed in more detail in Foundry Health & Safely Guide- No. 5 entitled "Foundry Medical Program". 4 7b t. A Series Published by the American Foundrymen s Society NUMBER 37 Foundry Health & Safety *>l<t soo'* VENTILATION CONTROL IN THE FOUNDRY INTRODUCTION The American Fouridrymen's Society's Foundry Health and Safety Guide Series refer to specific substances to which foundry workers may be exposed. The presence and concentration of certain airborne contaminants depends primarily upon the type of foundry (ferrous or nonferrous), the molding and coremaking process (green sand, nobake, hot-box, etc.) method of melting, pouring, shakeout and casting cleaning as well as other variations in the production of the casting. When employee exposure exceeds the OSHA 8-hour Exposure Limit, or ceiling limit, control procedures are required. The AFS Foundry Health & Safety Guides usually refer to local exhaust ventilation at the source as the most effective approach when it is necessary to develop feasible engineering control procedures, where other basic principles of control including change of material or operation, isolation, improved housekeeping are impractical or would have little effect. The intent of this guide is to present a few concepts of ventilation from the standpoint of effectiveness, economics and energy conservation in an effort to result in a control system that satisfies the employer when investing in a control measure intended to provide a healthy place of employment. Some excellent sources of reference on ventilation control are listed in the back of this guide and include basic concepts of ventilation as well as design of hoods and systems for specific foundry operations and processes. LOCATIONS OF LIKELY NEED FOR CONTROL MEASURES There are certain basic locations in a foundry where excessive exposure to airborne contaminants are most frequently encountered, particularly when ventilation controls are ineffective or non-existent. The principal locations or processes where ventilation control is almost a must in every case because of inherent problems are, in order of decreasing probability: 1) cleaning operations -- free silica dust and metal dust 2) sand preparation -- free silica dust, miscellaneous binder dusts 3) shakeout -- free silica dust, carbon monoxide, smoke 4) conveyor systems -- free silica dust 5) melting and pouring operations -- metal fumes, carbon monoxide, smoke, vapors 6) coremaking -- vapors and gases dependent on process used 7) molding -- free silica dust, parting compounds TYPES OF VENTILATION There are two basic types of mechanical exhaust ventilation. Local Exhaust -- Local exhaust ventilation does as its name implies: removes the contaminant at the source. It is far more desirable than general or dilution ventilation, mainly because it is more effective for contaminant control as well as being more economical. Less exhaust air volume is required to control the emission of contaminants with a corresponding saving in loss of tempered air exhausted to the outside. An outside supply of fresh-tempered makeup air, necessary to replace the air being exhausted, is therefore also held to a minimum. Fig. 1. Pouring station. (Courtesy ofthe American Conference of Governmental Industrial Hygienists) Another desirable feature is that the air contaminant is not allowed to drift from the source of generation and contaminate other work sites. Figure 1 is an example of local exhaust ventilation control of metal fumes during pouring. . General Ventilation -- This method of ventilation is an attempt at moving large enough quantities of air in the hope that air contaminants will be diluted to a concentration which is not injurious to the worker. This method of contaminant control is usually ineffective. General \ entilation is usually considered quite wasteful in power to move the air, as well as fuel required to temper (heat) the large quantities of makeup air required to replace the volume being exhau>ted. DESIGN OF SYSTEMS A local exhaust ventilation system consists of l)a hood to enclose as much as possible the source of contamination. 2) a duct system to convey the contaminant, 3) a collector if required, 4) a fan to create a negative pressure within the hood causing room air to flow into it and 5) an exhaust slack to convey the air to the outside. A good workable ventilation system follows certain basic design principles. Air resists the movement of any object moving through it. Conversely, air can experience considerable resistance in its performance in a local exhaust ventilation system, beginning at the hood inlet and ending at the stack discharge. Hood entrance losses, friction losses, turbulence and other factors contribute to excess energy being expended in many cases without a corresponding return for this investment in terms of performance or desired control. Some basic concepts to consider for each principal segment of the system are as follows: Hood -- The success of any system depends on the ability of the hood to capture the contaminant. Known as control or capture velocity, this criteria is given in terms of the air velocity that is considered adequate to convey the contaminant from its source to the hood inlet. When the contaminant is being released within an enclosure, then the control velocity of concern is the velocity at which the air enters the available openings. For example, a minimum air velocity of 150 lineal feet per minute entering the front opening or face of a swing grinder booth containing the grinder is generally sufficient to contain contaminants within the booth. If this opening is 3 feet wide and 4 feet high (12 ft2) then the exhaust volume required would be 150 fpm x 12 ft' or 1800 cubic feet per minute (cfm). J OCCUPATIONAL HEALTH REGULATIONS MAXIMUM PERMISSIBLE CONCENTRATIONS OF ATMOSPHERIC CONTAMINANTS IN PLACES OF EMPLOYMENT Eff<tu July 1, 195S CONSULT LOCAL HEALTH DEPARTMENTS AND PHYSICIANS FOR INFORMATION AND ADYICE ON METHODS OF CONTROL OYER HEALTH HAZARDS TO ALL WORKERS AND INDUSTRIAL DISEASES AND INJURIES ON-IJ-T WmuU, \WoH) -n-i TEXAS STATE DEPARTMENT OF HEALTH OlYtSlON OF OCCUPATIONAL HEALTH Austin, Tusat 00103 2G3 Thaae atandarda vara mended and adopted by Tha Taxaa Scaca Board of Haalth on Juna 9, 1958 In aeeordanea vlth tha authority grantad in Artiela 4418 \ of tha Raviaad Civil Statutea, Stata of Taxaa, and ara promulgated alao in aeeordanea with Artiela 4477, Saetion 19. CONTENTS 1. Seopa; Furpoae; Availability of Partinant Rafarancea........................................................ .................................. ZI. Applicability of Figuraa Liatad Herein .......................... III. Raviaion................................................................................................ IV. Deflnitiona ....................................................................................... V. Maxima Parmiaaibla Cone ant rat iona During One Working Day............................................................................. A. Caaaa and Vapora ...... B. Toxie Duata, Pubaa and Miata C. Mineral Duata ........................... 1 1 1 1 2 0 9 O t KB 00104 2G4 MAXIMUM PERMISSIBLE CONCENTRATIONS OP ATMOSPHERIC CONTAMINANTS IN PLACES 07 EMPLOYMENT ^ Purpoie; Availability of Pertinent References Scooe: This regulation. applies to all placaa of employment In Texaa. it doa not cover maximum permissible doae of radiation or the minimum environmental aanitation requirementa, nor in* elude meaaurea required for control of community external air pollution or air pollution nuiaancea. p-jrpoae: '* The purpoae of thla regulation la to preacrlbe to employers the maximum average ataoapherlc concentration of contaminanta to which they are permitted to expoae employeea during an eight-hour working day in their placea of employment, in cluding lnduaerial eaeabliahmenta. Pertinent Referencaa; Copiaa of related laws, regulatlona, opinlona of the Attorney General of Texaa, and Advlaory Standarda currently applicable will be provided to any citizen of Texaa upon request. 1. Applicability of Figures Llated Herein Individual people react differently after exeeaaive expoeurea to tmoapharlc concentratlona of contamlnanta in placea of employment. Llated herein are weighted average concentratlona generally aafe in placea of employment during an eight-hour working expoaure. Thaae are not maximum valuea which cannot be exceeded momentarily depending upon, but not limited to, aueh faetora aa nature of contaminant; frequency of occurrence of high concentration; variable duratlona of xpoaure; probability of acute poiaonlng from high concentration for ven abort perioda; emulative effecta. Employera ahall conalder ebeae faetora prior to exceeding valuea llated herein. Revlalon Valuea llated herein are baaed upon information obtained from recent xperience, experimental atudy reporta, or a combination of the two. **gular review will reault in revlaion aa juatlfled. The State Boerd f Health aollelta and will conalder pertinent data baaed upon facta *Qd experlencea received from lndividuala, lnduetriea, governmental *l*nclea, or othera. * fiilinitiona i Industrial Establishment la defined to mean an inetituclon, a building or location related to manufacturea or to the product of induetry or labor. --f Employment la defined to mean any plaea where two or Bote peraona are directly or Indirectly mmployed by another for direct or indirect gain or profit. 00105 2G5 MAXIMUM PSPKI5SI3LS COKCSyCPATIONS DURING OKE WORKIKG DAY A. Gaaea and Vanora P.P.M.* Acetaldehyde ............................................................................. Acetic acid ............................................................................. Acetic anhydride .................................................................... Acetone ...................................................................................... (t)Acetylene tetrabroaide ...................................................... Acrolein............................................................... ...................... Acrylonitrile ..... .................................................. Allyl alcohol ............................................................................ Allyl chloride ........................................................................ (t)Allyl gly'cidrl ether (AGE)............................................. ... Allyl propyl diaulfide .......................................................... Ammonia .......................................................................................... Aayl acetate ................................................................................. Amyl alcohol (laoaayl alcohol) ........................................ Aniline .......................................................................................... Aralne........................................ ..................................................... Benzene (benzol) ........................................................................ Benzyl chloride ........................................................................ (t)Boron trifluoride .................................................................... Bromine .......................................................................................... Butadiene (l,3~tou**dle)................................ . . . . Butanone (aethyl ethyl ketone) ........................................ Butyl acetate (n-butyl acetate) .................................... Butyl alcohol (n-butanol) .................................................. (t)Butyl glyeldyl ether(BGE)(n-butyl glyeldyl ether). Butylaalns............................................. ....................................... Butyl celloaolre (2-butoxyethanol) ............................... (t)Butyl mercaptan .................................................................... . Carbon dioxide ............................................................................. Carbon diaulfide ......................................... . ....................... Carbon aonoxlde . . ............................................................... Carbon tetrachloride ............................................................... Celloaolre (2-ethoxyethanol) ............................................. Celloaolre acetate (2-etboxyethyl acetate) . . . . Chlorine............................................................... .... ...................... (a)(t)Chlorlne dioxide ........................................................................ Chlorine trifluorida ............................................................... (t)Chloroaeetaldehyde .................................................................... Chlorobenzene (aonochlorobenzene) ............................... (t)Chlorobroaoaethane (ClBrCHg) ............................................. Chloroform (trlchloronethane) ........................................ 1-Chloro-l-nitropropane ...................................................... Chloropicrin ................................................................................. 200 10 5 1,000 1 0.5 20 5 5 10 2 100 200 100 5 0.05 25 1 1 1 1,000 250 200 100 50 5 50 10 5,000 20 100 25 200 100 1 0.1 0.1 1 75 i00 100 20 1 36c 25 2C 2,1* CO 1 \ ** 5 12 15 *-5 12 1,050 36C 19 0C 5 3 7 2,200 7<*0 950* -300 270 15 21*0 35 9,000 110 160 71*0 51*0 3 0 0.' 3 350 2,100 1*90 100 7 ^arta"of"rapor or gaa per Billion parta of air by roluae. /Approximate allligraae per cubic meter of air. (t)Toxicological information or injury reporta on theae lteaa la of recent origin and aost probably will require rerieion at an early date. (a)Hev - Added 195ff. 0010G ..... -2G6 -3 - and V&pora (Cent.) -ioroprene (2-eiloro-l,3-^t4dln) ...................... -reol (>11 l*omer).......................................................... Cyclohexane ................................................................................. -yclob**8,001............................................................................ IyClobBOae............................................................................ ;yclobexeae....................... ..................................................... ;ycloprop*ne ............................................................................ Oecaboraae................... * *......................... Olacetone alcohol (4-hydroxy-4-methyl- 2-pentanone) .... ...................................................... Olborane....................... ............................................................. o-Diehlorobenzene ................................................................... 3icblorodifluoromethane . . ............................................. 111-Diehloroethane............................................................... l'2-Diehloroethane (ethylene dlchlorlde) . . . . :*2-Dlchloroethyleae ........................................................... Dichloroethyl ether . ........................................................... Dichloromonofluoromethane.................................................. l,l-Dlchloro-l-nltroethane ............................................. Dlchlorotetrafluoroethane ............................................. . nethylamiae ............................................................................. Dlfluorodibromomethane ...................................................... ) Diglycidyl ether (DOE) ...................................................... Dileobutyl ketoae................................................................... Dtsetbylaniline (n-diaathylaniline) ........................... , Dimethyl fornamide ...... .................................... - 1*1 Dloethylhydrozlae.......................................................... Olmethylaulfate ........................................................................ Oloxane (diethylene dioxide) ........................................ Otpropyleaeglycoloethylether ........................................ .`pichlorohydrin................................ .... ................................... >.hyl acetate....................... .... ................................................. Sibyl acrylate ........... ...................... Sibyl alcohol (ethanol) ....................... . ...................... ithyl mercaptan.................. .'................................................. l*-byi amine.................................................. ............................... Stbylbeazene............................................................................. S-byl bromide........................................................... .... Sibyl chloride ........................................................................ ilbyl ether ................................................................................. Sibyl foroate ............................................................................. Sibyl ellicate............................................................... .... . itbyleae cblorohydrin ... ............................................. P.P.M. 25 5 400 100 100 400 400 0.05 50 0.1 50 1,000 100 100 200 15 1,000 10 1,000 25 100 10 50 5 20 0.5 1 100 100 25 400 25 1,000 250 25 - 200 200 1,000 400 100 100 5 Approx. per Cu. I 90 22 i,4C0 410 400 1,350 690 0. 240 0, 300 4,950 400 400 790 90 4,200 60 7,000 75 660 55 290 25 60- 1 5 360 600 90 1,400 100 1,900 6U0 45 870 890 2,600 1,200 300' 850 16 #p*rte of vapor or gaa per Billion parte of air by volume. Approximate milligram* per cubic meter of air. ^ t^*lclo6ical information or injury report* on theee item* is of recent rl8la and most probably will require reYiaion at an early date. ^)Nev . Added 195Q< 00107 -4 - A. Gaaea and Vanara (Cone.) Ethylenedlamlne ...................................................... Ethylene dibromide (1,2-dibromoethane) . Ethylene imlne ...................................................... Echylenc oxide ...................................................... Fluorine.................................................. .... Fluorocrichloromechane . . ........................... Formaldehyde ........................................................... Furfural . ..................................... .......................... (t) Furfuryl alcohol ..... ........................... Caaoline .................................................................... (t) Clycidol .................................................................... Heptane (n-heptane) ............................................. Hexane (n-hexane) ................................................. Hexanone (methyl butyl ketone) .................. Hexone (methyl iaobutyl ketone) .................. (a)(t) tec-Hexyl acetate ................................................. Hydrazine....................... .... .................................... Hydrogen bromide .................................................. Hydrogen chloride .................................................. Hydrogen cyanide ....................... ...... Hydrogen fluoride .................................................. Hydrogen peroxide, 90Z .................................... Hydrogen aelenlde .................................................. Hydrogen aulfide ................................................. Iodine ........................................................................ Iaophorone......................................... .... (t) Iaopropyl glycidyl ether (ICE) .................. Iaopropylamine ...................................................... , (n) Haaltyi oxide .............................................................. Methyl acetate ...................................................... , Methyl acetylene .................................................. , Methyl acrylate .......................................................... Methyl alcohol (methanol) ................................... Methyl bromide .......................................................... Methyl celloaolve (2-methoxyethanol) . . , Methyl celloaolve acetate (ethylene glycol monomethyl ether acetate) ........ Methyl chloride . ...................................................... Methylal (dimethoxymethane) ............................... Methyl chloroform (1,1,1-trlchloroethane) . Machjicyclohexane . .................................... .... . , Hathylcyclohexanol........................... .... . . . . Methyleyclohaxanone ..... ........................... P.P.K.* 10 25 5 50 0.1 1,000 5 5 50 500 50 500 500 100 100 100 1 5 5 10 3 1 0.05 20 0.1 25 50 5 25 200 1,000 10 200 20 25 25 100 1,000 500 500 100 100 9C > 140 240 i: 200 610 1,650 35 260 80 80 p I; !r r. - * l 120 21C 3,ioo 2,100 2,000 170 V 9 C 9 m *?arta of vapor or gaa per million parta of air by volume. /Approximate milligram* per cubic meter of air. (t)Toxlcologieal Information or injury report* on theae item* ia of rec*oc origin and moat proLebly will require revlaion at an early date. (n)Nev value, 19581 (a)Hew - Added 1958'. ooio a 2C8 and Vapor* (Coot.) -5- Approx. Mg. per Cu. M. 1 -fmta........................................................................ ^tbyl l*obu^yl earblnol (methylamyl alcohol) 2yi ............................................................................................. M^tayl ............................................................. ............................... Ethylene chloride (dichlorometbane)....................... Hoooaethyl anlllae ............................................................... u lupbtba (coal t*r)........................................................... naphtha (petroleum) ............................................................... nickel carbonyl........................................................................ nitric acid . .............................................................................. .............................................................................................. ...................................... jfitrobenxene............................................................................. ..................................................................................................................................... nitrogea dioxide .................................................................... nitroglycerin............................................................................. nitromethaae...................................................... ............................................................................................................ nitrotolueae............................................. Octaae........................................................................................... Orone ........................................................................................... Pentane........................................................................................... Pentanone (methyl propyl ketone) ................................ Perehloroethylene (tetraehloroetbylene) ................... (O Perchloromethyl mercaptaa.................................................. Fteaol ........................................................................................... ftenyl glyeldyl ether (FGE) ............................................. ftenylhydrmtine........................................................................ ntoegeae (carbonyl chloride) ......................................... Pboaphiae ........................... ftoapborua trichloride...................................................... Propyl acetate ......................................................................... Propyl alcohol (leopropyl alcohol) ........................... Propyl ether (laoprcpyl ether) .................................... o-Propyl nitrate . . . ............................... Propylene dichlorlde Cl,2-4i?hioyopropene). ... Propylene xmine ......................................................................... ft) Propylene oxide ........................................................................ Pyridine................................................................ ................... Qulnone........................................................................................... dtlbine........................................................................................... Stoddard aolTent.......................................................... pyrene monomer (pbenylethylene) Sulfur dioxide ............................................................................... 100 25 ioo 500 ^ n ooi J-001 ' " * L0 5 0.5 100 50 5 500 0.1 1,000 200 200 0.1 5 50 5 1 0.05 0.5 200 400 500 25 75 25 100 10 0.1 0.1 500 100 5 250 100 100 U SO 1,750 9 8oo 2,000 0.007 25 6 5 310 9 5 250 ISO 30 2.350 0.2 2,950 700 1.350 0.8 19 * 310- 22 4 0.07 3 84o 980 2,100 110 350 6o 240 30 0.4 0.5 2,900 420 13 irta vapor or gaa per million part* of air by volume approximate milligram* per cubic meter of air. iclical information or injury reporta on theae item* la of recent ^l^in and moat probably will require reviaion at an early date. (`)Hev - Added 1956. 001Q3 2 GO" -6 - A. Gaaea and Vapor* (Coat.) Sulfur hexafluoride ..... Sulfur monoeblorlde . . . . . Sulfur pentafluoride . . . . -Tertiary butyl toluene . . . (t) Tertiary butyl alcohol . . . . 1,1,2,2-Tetrachloroathane . . . Tetrahydrofuran ................................ Tetranitromathane ....... Toluene (toluol) ............................ o-Toluidine................ ........................ (t) Toiylena-2,4-diiaocyanate . . . Trichloroethylene ............................ (a)(t) Trichloropropana ....... (t) Triethyl eaine........................... . Trlfluoromonobromomethan* . . . Turpentine ......................................... Vinyl chloride (ehloroethylene) (e) Vinyl toluene .................................... Xylene (xylol) ................................ (t) Xylidlne ............................................. (#)(t) Teflon deeoBpoaition product* , (#)(t) Pentaborane (8585) ....................... Appro*. per Cvi. 1,000 1 0.025 10 100 5 200 1 200 5 0.1 200 50 25 1,000 100 500 100 200 5 0 0 '6.00C i C 60 300 13 Stt 1 710 n o.- 1,010 30c 100 6.10c 56C 1.30C use 870 | 1 I 1 1 I V. * C B. Toxic Duata. Puma*. and Mlati Aldrin (l,2,3,4,10,10-hexachloro-i,4,4e,5,8,Bahexahydro-l,4,3,8-dlmeChanonaphchalena) . . . . Aamate (ammonium aulfaaate).................. .... Aatlaony . ........................................... ...................................... AKTU (alpha naphthyl thiourea) .................................... Araenie....................... ............................................................... Barium (eoluble compounda) .... ........................... (t) Beryllium........................... .... ..................................................... Cedaiua oxide fume ....................... .... ................................... Calcium eraanata.............................................................. . Chlordane (1,2,4,5,6,7,8,8-octaehloro-3a,4,7,7ateerahydro-4,7-mathanoindanc) ......... Chlorinated eaaphene, 601 ........................... .................. Chlorinated diphenyl oxide ............................................. Hg. fw: Cu. H.* n C.' c.: c.- C.' c.a C.: C.- r. 0. *Parta of vapor or gaa per million pert* of alr-by volume. /Approximate milligram* per cubic meter of air. (t)Toxieological information or Injury report* on theae item* ia of rec*nt origin end moat probably vlll require ravlalon at an early date. (a)Nev - Added 1958. (#)Until more date era forthcoming, it. ia* important that atmoapheric cnC|. trationa of theae meterlala to which worker* ere expoaed ouat be kepc aa near 0 ea poaalble. /Milligram* of duat, fume, or miat per cubic meter of air, 0011 270 7 T,*<g Dusts. Tunes and Mists (Cone.) Chlorodiphenyl (421 chlorine) ............................................................... chlorodiphenyi (541 chlorine) ............................................................... rhroic *nd chrooates (ee CrOO . . . . A............................ Crg herbicide (aodita 2-n,4-dlchlorophenox]r/ eehenol hydrogen sulfate) ...................................................................................... Cyenlde ( CN)............................................................ .............................. 2 4-0(2,4-dlchlorophenoxyeceeic eeld) ............................................. 00T (2,2-blaZp-chlorophenyi7 -1,1,1-trlehloroethene) .... Dleldrtn (l,2,3,4,10,i0-hexechioro-6,7-epcxy-l,4,4a,5,6.7,8, 8e-octahydro-1,4,5,8-diaethanonaphthalene) ................................ Dlnicrobenzeoe ................................................................................................... Dlnitrotoluene ................................................................................................... Dlnicro-o-creeol........................................ .... ................................................. EPN (O-ethyl 0--nlcrophenyl thlonobanzencphosphonaee) ... Ferbaa (ferric dimethyl dlthiocarbaaate) ......................................... Ferrovanadiua duet .......................................................................................... Fluoride................................................................................................................. Hydroquinone ....................................................................................................... Iron oxide fuse.............................................................................................. Lead..................................................................................................................... .... Lead arsenate .................................................. ........... Lindane (bexachloroeyelohaxane, gamma iaoaer) ....... (t) Llchlua hydride............................................. .... . . ................................ Magneslua oxide fuse .................................... Malachlon (0,0-dlaeehyl dlthlophoaphate of diethyl Bercaptoauecinata)............................................ Manganese ................................ ........ ..................................... Mercury . . . ................................................................................................... Mercury (organic compounds).................................................................... Mechoxychlor (2,2-di--aaehoxypheoyl-l,l,l-trichloroethana). Molybdenua (soluble compounds) ............................................................... (Insoluble compounds) ........................... Nicotine........................................................................ .... ................................ (c) Paradiehlorobenxsne .............. ....................... Parathlon (0,0-dlethyl 0--nltrophenylthlophoophate) .... Pencachloronaphthalene................................................................................. Pentachlorophenol .......................................................................................... Phosphoric Acid.............................................................................................. ftosphorua (yellow) ...................................................................................... Phosphorus pentachlorlda .................................................. ...... Phosphorus pentasulflde ... ................................................................ Picric acid ........................................................................................................ Mg. per Cu. M. r 1 0.5 0.1 15 5 10 1 0.25 1 1.5 0.2 0.5 15 1 2.5 2 IS 0.2 0.15 0,5 0.025 15 IS 6 0.1 0.01 15 5 15 0,5 450 0.1 0.5 0.5 *1 0.1 1 1 0.1 (llligraas of dust, fuse, or aiat per cubic meter of air. (*)Toxicological information or Injury reports on these learns la of recent origin and moat probably will require revision at an early date. ()New - Added 1958. 00111 271 -8* B. Toxic Quite, Ptaaaa and Mlata (Cone.) *** Pr Cu. h. *, Pyrethrum............................... .... ................................................................... Rotenone .................. ..... ............................................................... Selenium conpoundi (aa S)................................................. Sodiua hydroxide .................. ..... .................................... Sodiuo fluoroacatate (1080) ..... ......................................... Strychnine . . . ......................................................... Sulfuric acid.............................................................................................. TEDP1(Tetraethyl dithiooopyrophoephata)... ............................. 2 5 c.l 2 q,1 c.ij 2 0.2 TSP? (Tacraathyl pyTophoaphata)...................................................... Tellurium................................................. ....................................... .... Tecryl (2,4,6-trinitrophenylmathylnitramina)....... Thiraa (tetraaethyl thiuraa diaulfida) ......................................... Thalliuo (aolubla conpoundi) ............................................................... Titanium dioxida........................... .... ......................................................... Trichloroaaphchalaaa ................................................................................. Trinitrotoluene ......... .................................................. (a)Triorthocraayl phoaphata ......... ................................ 0.05 0t. 1 1'.5 5 qj 15 $ 1.5 0.1 Uranlta (aolubla compoundi) ......................................... ..... (inaolubla compoundi) . ............................................. . Vaaadiua 0.05 0.25 (V2O5 duct)........................................................................ O.S (V2O5 funa)_ ................................................. .......................... _0.1 Warfarin (3-a-aeetonylbenxyl^ -4-hydroxycoumarin) .... 0.5 c (t) Yttrium and inorganic coapouada ........................... .... 5 Zinc oxide fuaea..................................................................................... . IS Zireoaiua coapouada (aa Zr)............................................ 5 C. Mineral Quae a Aluminum oxide................................................................... .... ...................... Aabaatoa....................... '............................ .......................... .......................... taae (nuiaanca, no fraa ailiea) . .................................... Mica (balow 31 fraa ailiea) ............................................. .... Portland cement.......................... Talc..................................................................................................................... Silica Sigh (above 301 fraa SiOj)........................................ ".................... Madiiaa (5 to 501 fraa SIO2).......................................................... Low (balow 51 free Si02).................................................................... Silicon carbide ...................................................................................... Soapatooe (below51 fraaSi02) ................................................................ M.p.p.c.y, 30 3 50 20 30 20 3 20 '30 30 20 JMllllgrasa of duat, fuaa, or aiat per cubic oeeer of air. (t)Toxicological information or injury raporta on thaae iteaa ia of rac*^ origin and moat probably will require ravlaioo at an early data. *"Mllilone of partielaa par cubic foot of air. 00112 272 K FURTHER AFFIANT SAITK NAUGH: c<k--\/-Qa Darin V. Osmond SUBSCRIBED AND SWORN TO BEFORE ME on this 8th day of April, 1998, which witness my hand and seal of office. t- OFFICIAL SEAL JACQUELINE A WRZESINSKI NOTARY PU81,r STATE OF ILLINOIS J MY COMMISSION EXPIRES:08106100 ......................... 2  : .:cmvi. >, - NO. 93-042852 AUGUST GORDON. ET AL. VS BOB SCHMIDT, INC., ET AL. IN THE DISTRICT COURT OF HARRIS COUNTY. TEXAS 80TH JUDICIAL DISTRICT AFFIDAVIT OF BARBARA J. BARRON Before me, the undersigned authority, on this day personally appeared Barbara J. Barron, who being duly sworn, on his oath, did state as follows: 1. Iam over the age of 21 and am fully competent to testify as to matters set forth in this affidavit. 2. The following documents, which are attached as exhibits to Borden. Inc.'s Motion for Summary Judgment, are true and correct copies: "Exhibit C": Central Foundry Plaintiffs' Answers to Interrogatory No. 6: "Exhibit D": Excerpts from Deposition of Wightman M. Cannon, Jr.; "Exhibit E": Excerpts from Deposition of Robert Yaw; "Exhibit F": Excerpts from Deposition of Billy Don Kizziah; "Exhibit G": Excerpts from Deposition of John Paul Singleton; "Exhibit J'*: Texas Occupational health Regulations, OH-13-2 (1958); "Exhibit K": OSHA citations and records related to Central Foundry (identified in Deposition of Billy Don Kizziah at 192-200 [Exhibit F]). FURTHER AFFIANT SAITH NAUGHT. Barbara J. Barron MW/117194 Ootober 25, 1978 OSHA - BEAM 2-Year Initial Noise Abatement Period Central Foundry - Tusoalooaa, AL Anting ABA for Federal/State Operations A full soale foundry inspection was reaently completed at Central Foundry in Tuscaloosa by the NEP team. Thirty-two (32) serious violations nil fifteen (15) other violations both with multiple instances have been proposed for oitations by the team. Further, a probable Berious violation with multiple instances for overexposure to free silica is likely. One of the grouped serious violations is for multiple violations of 1910.95(b)(1), failure to determine and implement feasible engineering and/or administrative controls for noise. This item oitee twelve (12) different areas. The areas are: #6 Foundry, #6 Kill, #3 Foundry Core Room, #3 Foundry, Llnh Belt Dept., #4 Hill, #4 Foundry (including hot metal crane operators), Semi-continuous Dept., Industrial Castings Dept., Five (5) foot Millroom, Ten (10) foot Millroom and the Ten (10) foot Kill Abrasive Saw Operator. The company asked for a minimum abate ment period of 24 months for this item. The industrial hygienist who participated in the inspection, Charles Cashio, has expressed the opinion that the time requested is reasonable in consideration of the task at hand. Due to the large number of items oited and the substantial amount of engineering controls which must be simultaneously determined and implemented, in addition to noise reduction, including: extensive electrioil corrections, extensive machine guarding/ and repairs to craneB, I think the 24 months abatement period requested for the noise Item is not ezoesaiva. With the aompany having their eoonomio and technio&l resources occupied in several areas ooncomittantly, the effort to correot the oited noise problem will likely take the full abatement time requested. I would therefore like to recommend the approval of a 23-month abatement date which would take into consider ation the tume required for processing of the citations and still Aotlng AHA for Federal/State Oper. 2 afford the aonpany the full 2^ months desired. Your consideration in this matter is appreciated. October 25, 1978 EON 13. EIKEE Acting Supervisor, IH EDE/lp f :CUfATIOMAL SAFETY iD HEALTH ADMINISTRATION NARRATIVE 1. CShG no 2. Raoort No. PVLtV 1 V7S \. Data Ii Tima of Entry: slight 9 #/* a. EVALUATION OF SAFETY ANO HEALTH PROGRAM; ComprrunMinin ol Salatv A Hltn Program Wriiunl y ICodai: Copy EncJoaad? Y Cam/nuruaiionof Propram io Empioyaaa How? rtplLfov [\i <- ful-rrt Sataty Matttnga Fraquancyf /)p i 1By Wnom -Par* r% t- Ctfjarfr utnr- i nlorcarrnt XL_ i*^*<lLK.t 1Ya -p**a iiik#4 r> -iIaH cr it? ptr>. f i 1* Salaiy Training Program Haalilr Training Program Salaiy Stall Haaitn Stall Q ^ Accldtni/ln|wry InvaaUgatlont Parformtd Pravtniativa Abtlon Tafcan (2) 0 12 3 0 12 3 N D' 7.C C*9+* 16. FOLLi W ENPD Haaitn Monitoring Program Haiard? d/*'tc tuly--A.J-, l> V aJ* MadleaI Program* Fr.qo.ncv? pp. Am^l /.ijiw.jf________ A*"'? --V-C._Cmi'u I__--JK.rir~ p i bfi_________________ Contant? Haiard Control -- Enginaarlng A Admmiitration - Panonal Protaciiv* Equlpmant -- Ragulatad Araai -- Emargancy ProcMurai Racorda: (Too) -- (jOl) -- ft02) -- Suppiamanaary Haaith II SH, ipaciiy_____________ Notica to Employaaa IPoatar) Add'l Commantt: _____________ 0 N FvFTHLAAL/ARttLi: 16. Accompantad By. . -----PlAfty kerr;/f -A mwaiII Rmun Obi4/Sinadi All*dlv Vlouiil 2) EncAm*9 Comouinci g 10. ADDITIONAL COMMENTS T'Ars. Jlea- *-> I I'ln^pl___ fiJ3------11 tt-C---- ti_L i a > *> rein Li ,_aL An__JLS1I Ify-'* ra !.'.^4__Tie a -fj> /'>/ A a > <f C .'At------a-------f -- A / If/ **/ J ff-Li'** p r * j r A f*-,. -P*' P1 Tl KW/r f--- "`V rr t w fek'jL/eJ Air ----- /.<>"// 4 ^L II nlmCt.---- ^ L jtymt tit--------------------ksLO. cent jo. 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COJL. ./a r c-A*6 tir*___ m f T / * j- rAt9J/iDiJ^t.__4TUhMnTi T/ <-1, f<<y^ialr*41 __ T4Pi__ rMr) -Tij e S 14 J * r X.4*> *-4__ 4l< SaA-is /.D 4^ A !//'OAi , />^r SA.*Jte afirer+.J___ -Pm 1/ Da p/A/.`tfiZ a//<< hir Stl*J CouiJ ir V-Lt 1ii4*4/ J2kit iui gANrf < -g^qgiJ /y__4Sa/rN ,MeJ 4-ka-h j y ^y<y*iy fAXfr 4|, -tkr gN,WAm'<( re ~4/a4 ^// Af**l 4AJ/I ___Sj-adte **>J GdJ1 Aj -fA ^fz^rHivij /$*/ J* A>7 / 1' 1 Aa^a>/ -L__0/ r & *6 ./HiiNA^fnr /'/ mm* u** yy ruitf iia7^" .g*c / j 4. T4atJQ 1C./E < S t-l > K) *< jSeP gr *4'**a. ^<*4/ il.g m -fl n 1.pj-ttif.* t <___ a m*/ ------- oleAcaA--A-vd >-e. i a L, e Jt xnAt A d*C; e,- ~J*r V -2--Lixxji------ tiHI-e--A.Pftr4____4j____it a *\ji a -P f wt i'p m * .*4 ------f - * * * * * rt i i r f ---------------- --------- A W 5T --tf'eAr* U)o |/<N A|/4||/ 4frfin/4 .'>J gA^g ^ ^^ 1 an4 t^i r.'/,"4y ---- x.fiatt-------ZZdX----- /___________________ dj> ^4 fArgucJ to /+ e b aj e owai-i//< gooN ----------^/'j') ^jz.----- r-c4x~^ __~p* ^roir*""*^ 1 --f ,, jj 7 - -*- - jftt i rmI* n -- -- " -*a r --r <-* - 9 g-f PPE .______________ ______________ ------------ --&lA-L.y______ ^/ant >~f~A*r} MS AifieJ o tJ 'j'A.r A/f^e/e*/ / Rul _______ -^` rv-j---- _^a-i----- ALC-----Qti *jifo S+1 i-a J 4~la1/ /a-t 4'f /. --------- ^~~yB------- a~ ^^^ ' i1^'1--------<3t------ SAr-te 4j--*'***'- /??* ft*.*/** Art^ -----/4lC-t-- --4 -- __ ^Aliil-tj----- ---o- -t--^-j--f--u-- -r--r------- -7------------ P~et '!------k----c------- A---r-+----i----- ^/* rs--------J---'-A---e---?--.--------------------- i_|' m < -----SL^ r g 4n--JAjLs.--_jUi4--- A-__ rhttfi Fuq AaJtcs ma ,4- , g^ggffe^i.i PIq^T-. 6 *0 It Rvw ruiarc* Gwrd/&i*na*,ai ; - . additional comments f; r 3^T-A L.---- * \ tNj V^<~ O \ 'Ct -''vA-;'. AY '"'V* w f" fVvn 4r^V'i.u~>.\ ___ Li?**--" <a\-L\-7,\-1Ci -naA s C lWx AcV N\`Va a-- C~c' A7 '.' vv^.^vV' --------- X_ rr^c.-cy. C-. ' -X ew r- ,--A.-- ' \-W- r\ ITl* UL'ivt \\\ ,\ \V - r. --.: f. A -c >:-A ^r> Iir..rM l., \--------------------A-- ;--: I ' A. V-A'-A - A-A'.J~W ^ ___ f ------- --------------- ~v-----------------T---------------- -AoW_*A V- .a A-\k < yL.vt^ 'v^cA t g---c- A a^.(-x 4A C TT c\ka:< aAt -------------------- rQ---~---~--i-v--~-\'-v--\------~-------N-------A--y*-- A^us>i- 7 4vw- ' v-^c :y AT" u. ^ \-tW' y wOnCNVC (\ IN \ '- >\>'"`\ > 1. ^^vv-,.~)^f- 4 ..V>\ M '\ Vi Cj ca^a-a ~n. v4,.\-x. Vt/>-"\ > r*v\ _\ _Al ;>. W-Vx^-r "- "V I r.v.\ \ ^TA.V-i-wim^'' A.iTT --- - \ >' ' V:.^ :_ ________ r-t \ I r.v.l'i - '. -r-\^vr.i. -----------, - L' - ------------^---- TvA l^-AuAr^,. A `w,A \ ' AVVlA A.-> Ny-vvrv^ f o 4 -U i, 'jy---------y ----^---- - r ... c rr-txCC * f A ~\Ao7^ iv...--.---'--c^"\1<>V N.1Xr yIcn^vrv.1'<*Xi vi vvA ---- ,\hi~XT>vn*\.vV Va.^> i.x- ----v . ? i C. ^. .^ I'.^-. \rr .- ^ C -\.A V~t\^\Qo.w__2_TyA t t rrrrvv^-ww^^.'.UltCiuLL wNi:w-______ g c k----------1----. 1 --: \Y\V'C: XVv__-- Kc'w wa>A XAl C ' o^ jvt - ;A' (>."-.'. i---A X'^Tf ~ ^vxCA/.V^,A.d^>Trr>---.' <tii~-., Xs~v\^W- cc.,c^--^rrss'Vt^___rVc ^ VW^cl rv\\ T^T-rrvC 1"-XLtAi o'vA\ D~T~v Au-^--<'\> Cc^C -vAi u-vHryI 'x 'Vt. -- y .--^ \i*v ^ c*"KCuc'C.vcl..-\ T c\- 4- ' -T v \.>v CJTUU C.Xi.-^. ^ >>-*->VVaLoT ^'Cv^X.-N rd'iTs^ \^jp \oxJ * V<'rv wv\f fk 44k,Cl ( -Vw^40-7i^-.t u^jri- v-nrf --' -- ' --. V t .,\j^\ ~4 OVJ- \>.- ' ^3*v>r-T\-g 9 i>^ w\---Ay- a '-- ' -I 'i- ~V^-- \>j>u^,ia.fr ps %AsV.^ /> Co ^ 0,^-4-- c fA<\ C~^ ^y\ \N^S .Ox ~rv^ ^ V- yvt/^ X/NA/'. V v ^^ \ \x.Ar \ v4 __________ V ww.' -^T'Xiu.lA M--gXiXo> ^ tv^rsf, ^ j v.u^rs^___ ^\yncr\ .!c. f V c ~Tac-\jrtX V- 4V. 'v-- ~Vx.<7 \ l-' ^a). itw \t^n '^ c r~--*x L^--^ > ^ ^fO\^yO ___________________________ \^icrvV(\ \i Vt 4 vvu.vve ______-uV\A Vj(.^pk. ' v-A. c Ci' -A C C~\ \, A VJ- } fjw--. A c.rr V. f <.^i-^-- Cov>>4 /w- V ~ V \^ .UlYou-eX v\-ia U.^ \i.>V\f . rXro^-T'-c.^ f i~~Vr , \,o. ^i-.-' C~-> E^X-O -l--r ^ ^^ | 1~ Vy `Vv, <-*\ W VV.'---- L\ ^C, t\i i'VL^vl\ ~Vl'-^ K,<. AJLX> 4* -u- . | v, L 1~ --- ^ ~ ~- . \ --ri C rwr n______ V>vyr\xc.\ -->->.\V-C'.\uO.>~X___________________________V____________ 4t-**CVr--% ------- Vx' ~lc<rv\ \'iC\c^-y~^ i xv^u^i-1 ^'.,7 ~J (4?Toa^.vJ c^\ l UC.-U3A^ C^X \H,T- )4' , X ,\ I A.-W l\^ ^ViTj C.\, --i; \\\\~~IS O^. f\ ^-L~' \f*`{.\-. (\, ) p\ V~A\ ,\a'~i. C'^'-Na' c., \. ''. . * \ \ E V>"Vt (i *' ~7 <* V~ Lk >. A .A'x -V(<~n ~^<T An *?>ft'.-^C. -. ^ -------' L^.1-^'. -> ^v*-- \ c mo & 30 AODITIONAL COMMENTS ciu< -P^h / eg__ w;-jl--U m r..fcA> npj,tthl M.1 hi /7 p _Z_ --AU-^.l.J l:A ai. --La-- XSHa Ps. ti r * C L ' t>---, ><* *> / L/- rr* c * < , V/ -c. mp/tjifr-- I rn. inlay*.*-----------gg.*V-/g, l Ji^c muter----/r^a/, u- /*a/ c. ifc II \ *C.gA>-4fgA<g f_<_ ( -Aj rr C/ ;+ uls* S _allmJL i-Ia>\j< J___ 2^ t-gM-f A V 7 rr< tr Pa /a g r p"*^ g------ jJt r* c T fj g vC>h g- ~.>>-/> cto < /g><--ggiv/rIr^g^f ^x--J f AMp (eyf tx A1 . i'/-' />/*__ rv/jvg- u * ~ ^ >> 'P?t?r*r**t>v g -* f r** ____ ft/sc pJimP -Mr* /J +~C^<3 SaLtPP _A*-. ^ O^Jt-rD PP~' yL- &o-w P- -a. -P- - -, i r u. 0:~'JiP .___ / .L~-*P - o-oegif vr -7QztjLr-OrP^-t-l.o^.^p Tf\j\jzr-^r-ZjJllL^H^U1ZzJL^a-Li GJJL JLr r Ai^LP -4-0-!-- yu-j^j. jp+- ^ JL JLP^Aa^ Jo JL^l y/^, ,^ a^?l. /? -- go^/i_ ^7?_iv.^ 7^f, 'l r Tt / ^ ^7. " ?4g<l^A>*^ h/hrt^t------ ------ .g W7> so//*/?# CXft^L =-=j ____ ^2. ^7 a-- - g ^ gi ' * Q- r xt-rPtA iTM m g---- Jj-a-a-$Pask~. Toae ^ - >g>^ o ^ ^.g- - 7!V i.__ "@0 Ph--.^ At^c^_^tP c.<M-e> fr-u>4A*i a:--f " n^' rrt'T~~ ^ --/^L/^^^rrw^T ^rcu* r/i tfg^lATrVf-i~-r__ _ ^ ' -0" 2.0 0 -fz. h f?Ph zPPj-tP - - iy' ^ Jt-'zrf.L 'Ttu. ^22iOtsabP___ lg6^.A_ EL, g, J=srulA P*.____ JL^rJP- \ - 0 -tP--' ^PZA ff lit* ^ P 7p=. r~ r -^r ,7g--tZ-P-/-?t- jQM~. J-/- si ff Pn PrPP/)_~_Z_ Z^^a*L ___ 77 A ^ `' * SLUP- _h) Jj a 0 r3Z^%~hPZ Q~ rPJPL------^j~a~JLP PP. j2__ ^^-J2____ ^2_____ y&g**.... CUtT' <- 7f ^ J ^ ?Ag< yrtL C.S/+C 7h */? ^ ^PoL___ <., jpLP AOm- rd-e< ",-f,^g. &A70,.A00IT*ON<kL COMMENTS TT r-o--r-*--7 - - V-f -L-- 22m*-------- Lll/zS/n ? rr-A--7--; 0 S'* -rQ f ^ ~r-- 11 f 11 * * -. *--a .^sfefefo ^vU - o< Izi/Lt. . .*t--r/tiTt^r,-- 1-i-ni a_/_i__ ~ 0 .Kzt aJO /O-v <L-<f . a ~ffi< A .**r P^XJ. e^ <i P ------- --- f *--/ *----*-- ' --/- --r/^2 *-rj-^.*P -- ~^s4 0.~ ** - /3^ vi/' -ZT-~. _ ^7 -^IL*. --<^L. r- - P 1 - - -zr __ _______ -^L _222a ___ <i-a-c+ A _______________ ^u^e. er^e. --. -. 1 " -- 3^. so- -ucd*-* ^__tr^ur'-i----- gy~>i .r am */-.--f7ee/s 4grv___r~?*r 7 flfl 1 ---- ^ C.f=Z. 4"^7^2*727 2Swt f*WY------idao. `T-C -7 CITATION ino N0T.IF1CA .j OF PENALTY Area" Office 2047 Hmyaa F>oad r'i i---i Alabana 35216 Serious 13 to The Central Foundry Ccepany P. 0. 5ar 188 , Holt, Alabana 35401 I a. ; MCio /73.-PZ6: \AMA n;i. mss. Pf NAlTlES ARt 0U . WiT MIS \< - OArS Of INSPECTION OATE 8/23/73 - 10/18/7S INSPECTION SITE. Liolt Hoad TH LAW REQUIRES coov oi mu Citation Or OOtted immtOitKiv m piomi nem place at o near in* location 01 the vio- lanonUl ciiao b*io* The Cuidoa mutt ramam oottro until inr **o#i.onj curd de- R C iPT Of THIS NOT I F ! : A' UNIESS CONT ST (Str mnow 6ookii) . TK.l SkIiO" 8* Ofutore B*u> Potii low hac Orm courciro or if 3 xoitm] oavi traciudm) MMktnoi ano Frorrai hotidayt) vwhicntwci * longer. ...non O.KMB.. vioJxtOAl Ol Ih. OauplUMlI Salary " Health ACT ol 1970. Th. Peniltvl.ee> l*ile '* *<> O" me.. ''eliom , (ouki me moteuom lento to m m.e eno" by the aeiei luted below tnd ety the peiteineioioooied. unitit ~.m.n IS woitm, oevi weeteodi end Feoeiel hoi.o.yi) lion you. itceioi ol mu citation and penally you mail a nonce ol Cornell 10 me U S. Deoe.imrm ol Aiee Ollite ei the eddreu mown aoove. ISee the encloted booklet wtilch oull.net your teiooniibilitiet and courtei ol action ana mould De n coniwnction with Urn lotm.i NUMBER JQAHO. PECULATION OH SECTION OF THE ACT VIOLATED: OESCRIRTION ________________ i I' OATE BY WHICH M 1 viOLATiONMUST BECORRECTEO ' PINA;' CFR 1910.94(a)(5)(ii)(b): Abrasive blasting respirator(s) were = vsm by all abrasive blasting operator^) using silica sand in nual blasting operations where the nozzle and blast were not pliysi- lly separated frau the operator in ad exhaust ventilated enclosure: ] 12/13/7S <//r J630 Abrasive blasting operation located in area adjoining the iaiustrial castings department (respirator progran in coor-- pliancc with 1910.134 Bust be instituted in connection with use of an abrasive blasting respirator), on or about 8/29/78. y ja ) CFR 1910.95(a): Protection against the effects of noise vaa jt provided for cuployrse(s) exposed to sound levels itiiich ex-- jedod those listed in Table C--16 of subpart C of 29 CFR part HO: Hearing protection was not vorn by all exposed employees in the: t-fir ninh'i 10/15/30 : tl,C i<l tl : eP O* w' a) j6 Foundry. -b) #6 Hill. e-c) r/3 Foundry Core Foon. i/d) ^3 Foundry. -- e) i.inW Belt Depaxmeat. l/ f) #4 Kill. g) $4 Foundry, inglttri-tTi^ hot crane operators. ~^h) Sffii continuous depajtamt. ~^L) Industrial Castings. - j) 5' HiUrooo. -^k) 10' IK 11 roan. ' 1) Kill abrasive sav operator. On or about 10/18/73. 16b 29 Cm 1910.95(b)(1): E2:plc7yee(s) were subjected to sound lereLs exceeding those listed in Table C--16 of subpart C of 29 CFR part 1910 and feasible administrative or engineering controls were not utilized to reduce sound levels: 19/1S/P9-.' r. AREA DIRECTOR "~0q "I fi, .U lfratt_________________________________ i__ F_St OTtCE TO EMPLOYEES -- The liw gtvei an employee or hif EMPLOYER DISCRIMINATION UNLAWFUL - The la.v pro : T OT AL pi -omtniauvv the opportunity to object to <ny abatement Pete hibiu discrimination by in employer 1911011 an employee lor et lo a violation < he believes the date to be unreasonable, filing a complaint or lor exercising any rights under ihu Act. (OR CIT_J "he conieu muii be mailed to the U.S. Department of Labor An employee who believei that he his been ducrimmaied : r*> *<rj Odicc at the eddreu shown above within 15 working days againK may file a complain! no liter than 30 days alter tht "OOl_( .aduding *feaends and Federal holidays) of the receipt by e emoioye*r ol this citation and penairy. ditciiminetion with the U.S. Department of Laboi Aici Office ` Imttifj if C at the addreti mown above. km fswr nnrj^imi IT1 rS AND COURSES OF ACTION -- The enclosed bookletoutl.net employer letpont.b.l.ne. and ShO No. VHLyr ^ j 2. Rfoo/i No ^ <-ns~ 6j Iniunc. jAV6 fO Coot /-yjy U.S. DEPARTMENT OF LABOR WORKSHEET i 3. 0**/Tut v : \</l 0/79' I : Sl.nOArO AliwtOlv ViaulKi [4a. Tv ' 40 Nurnot* ^ l/ 8j . AJMUmtm Ptnoa ! b ,cfij vOC'if M./'Tno ( TjO No b. AV^/Viniuit mio^monon. \ 9. No. pi mil \ C fit* ___ ^f-rrU" ('/'rt'rtff /.r/nVrf7 <h rfrc-r Sk/tZirr-nj j-U.J^du i /L\ ------- ,----------------a^r,<y/r,,, /`(fO MV mwn-/ /y , P*` -----r`^s^Uf-nL ^ Corn o jSTAnCE DESCRIPTION la Hmriii-OHi ,;CortU-ACC.: D Efluio.:c. locmon: tna d Inixiy/lll.l. /O f^/JA/n Si *>*<77*/^ ^ a /n, ______________ Ahrzt.u* Luz<.J-P~<.n ______________ ------------------------------ -------------------------------------------------------------------------------------- ^ f. /Vn rrli2?~------------------------------------------------------------------------------------------------------------------------- -O___*>-" 2nnn*_r?gi/f Oi'^ r^7-1 .. ,,f/,, ;.y,ryi rfi~l I ^ J,.< h-,1*? b. f-*- .Luk nrr<.iurc--iyr>/n $U\ - trA**/) *v)('>r */= rgy (/'-/JCtr) s --WZ/<- - -- . A//i/t-TBjy ~2/OLi nfcS7SSC Ss-A m?s /Q-^T^A^ ~J-l .-? yl/(7 JLk/\7' sVfrr.Vt-trD' S /c/7 D*-!-/ < -riSHE S->'-srry jt yi^-j Aif+~ Corn'd 13. PHOTO MPLOYER KNOWLEDGE. <---/i-j *{u.nJash >uftl ^opi.tn R~r~ /y-r w>^n> 3MMENTS (Emotovar. Emoiovae. Cioimo Coni.) ^^7/ r----ZjO^OJ--taaruu'.^j^r i-n^u-r, F>a-~- ch,<.to -K,>.**/,/ ''fr'S ttnea R'r*~ dm -fri /l.atH: . S k.m.i ^'f^ti'4---- lltt-r -Hin A ii -i^iy L, .h ---- ________________________________________ ___________________ ____________ ______________________________ ________ _ '7C/7/' Spcf* c kj pit IH6R EMPLOYER INFQRM*4 ^T__nJb_ --**J y i Um 4b w^ c n_____ y L2Z 0 !/ I/W b Pfou. o' lA|urv/HI jOl : 0 Gr4viiv-6ito 4 No. Cl. Ofvi Uncorr P*n*tiv c. Ttmci Rcoasiod/ j 09' 01 Willlui XJ lT' ' "7 A r,W -- 1 | 1 ) Sl4* 1 nr d. Adiuttmani Factori 21 Good FMh nr 31 History , yA, 4) Total , *+ *n Prooosad AdiuttaO Panaity &^=!--------------- 7*----- o Nu i ir>w * >- s v 'ta #ffice V v d ^Anmn 35216 ^QZEBEMl <11 r Citation issued on 2/23/79 is Attended: The Corral Foundry Company l*o31 Office Box 18jSi Holt, Alabama 35401 * REGION penalties ABE OUE WITHIN U INSPECTION DATE. 8/23 - 10/1S/7S INSPECTION SITE .......Halt Hoad Holt, Alabama THE LAW REQUIRES mat s coov oi hi Citation cm ponad immaaiaiaiv n a ororm nant piece at or naar tna location ot tna violeuonts) citad below. Tna Citation mult ramam potted until tna vioiauont euad be low nava CMan coriactad. Or lor 3 working DAYS 0? RECEIPT OF THIS NOTIFICATION UNLESS CONTESTED : (See incioico : Booklet) ' Thu Section Mi 8* Deteeneo Bator* Potting dayl taicluding waaninat and Feaerei noh- daytl whichever a longar. * viol.iioni o. m. Occu0*iionl S.l.iy .nd M..I.I. Ac. ol 1970. Th. P*"vlil lin'd 0.io~ -- ,' v.oi.i.on, T.u.1 couki Iiw wioiaiioni i.l.n.a to in inn cu.uon Ov sum luiaa Balov, and pay tha Panamai ptpppaad. uni... vnimn IS wo.a.nj oavt ,umg waakandi and F aoa/al npiuMy.) irom your tacaipi ol ii cuaiion and panaliy you man a noiica ol coman to na U.S. Oapanmam oi A.aa Ollica al lha add.ai. mon aoova. ISaa iha aneloaad BooUal -men oull.naa you. faipon.iOH.ua. and cour.a. ol acuon and mould oa n coniunciion with this lorm.l __________________________ -- \ number 40AAO. REGULATION OR SECTION Of THE ACT VIOLATED: DESCRIPTION DATE BY WHICH VIOLATION MUST BE CORRECTED (Lerlxed shown belov) cm 1910.1000(c): idjpioyrsets) vere exposed to material^) in -c33 of the E-hour h weighted average limit(a) listed for that ccriol(s) in table 2-3 of subpart 2 of 29 CFH part 1910: Free *''*>*=> containing dust at the following areas -- ^ 'Z (a) iinkbelt holwnan. 2/25/80 `'I'h 1900 1 (b) 'i jfc) No. 6 foundry permanent mold - core and iron p .^.u- pouring areas. fijl". 5-foot uill - oillers, ponders, clippers. ^ * . .. A\ iky tf (d) ,.r<M (e) / (f) 10-foot nill - millers and grinders. 5-foot centrifugal casting department -- operators, J^i valvcuem, craniwn, and core pinners. ^j iinkbelt Duller. W "U-Aai. -``'`.ft /Cr,: di A m J (g) No. 6 foundry permanent mold shakeout. 2*'"^ - 4gg (6) 10-foot centrifugal casting department -- pipe 9 T roller. --d *j 3 /* u (Revised as shown below) 9 CFR 1910.1000(e): Feasible administrative or engineering controls ere not determined and implemented to reduce raiployee expo sure (a): (a) No. 6 foundry permanent mold - core and Iron pouring areas, shakeout. (b) 5-foot oill - millers, grinders, clippers. (c) 10-food ml n -- olllers and grinders. (d) 5-foot centrifugal casting department -- operators, /alvemec, cranemen, pipe rollers, and care pinners, 1 in belt miller. kREA DIRECTOR C. L. Wvatt NOTICE TO EMPLOYEES -- The law .-iv^s an employee or his epretentaiive the opoonunuv 10 object to any abatement One iei tor a violation if he believes the Oate to be unreasonable. rne contest must be mailed to the U.S. Deoartment ot Labor ea Office at the aOdress shown aoove within 15 working days "lading weekends and Federal holidays) of the receipt by 'mpioyer of this citation and penalty. EMPLOYER DISCRIMINATION UNLAWFUL - The law pro TOTAL PENA hibits discrimination by an employer against an employee tor FOR THI CITATIQI filing a complaint or tor exercising any rights under this Act. Makeciteckotfc An employee who believes that he has been discriminated ' Ord*< K*y*Ul against may file a complaint no later tnan 30 days alter me "POL OSH discrimination with the U.5. Department of Labor Area Office (Atflfgl# OSH on Aemm* at the address shown above. OYER RESPONSIBILITIES AND COURSES OF ACTION -- The enclosed booklet outlines employer responsibilities and ot action and should be read in coniunciion with mis notification. CITATION ANO NOTIFICATION OF PENALTY OSHA 7 REV S/7G fATJON and NOTIFlC. <r r ralirlnr*,* Araa Office c*njh Bo*d 35=16 , g/2d/7Q : P468C- 17' |> IlSOlOk, ' inn I , . 0.150 INSPECTION OATS 8/23 - 10/1S/7S V ^UfinB jjmiexi on 2/23/79 is AlQ^Oia *' Hit Caitxml Foundry Company fare Office Dax 186 Bolt, Uihaaa 35401 inspection site. Holt flood Halt, Alahama THE LAW REQUIRES inn cooy oi in Citation o posted immaoiataiy m 4 oom>nant piaca at or naar tna location ot in# vtolaitonls) cited Deiow. Tn# Citation must ramam ooitad until in# wioiationi citad oalo* he#e been corraetad. or tor 3 working oav> ItfcCtudmg waoaanot and Faoarai noi<Oayit wnicnavar it longer. j nrrffrti I ina Occupauonal SUIV and Him Aci ol 1970 The oanairyliai) luted oaiow ara desea on tnati vioianoni r.i.rrad 10 m mu c.non by m, b.i.i i.n.d Oaiow and pay ma panamas psopo.ad, urn... wiinin t5 working oayi ' N!HCndi and Pada.al nolidayil Irons your racaipl ol mil cnanon and panallv you mail a none. ol coman io ma U.S. Oaoanmani ol 1 oTlLTai ma adoraii mown aoova. ISaa ma aneioiad bookl.t whicn outlinai your raiconsibiimai and counas ol action ano mould oa penalties ARE DUE WITHIN IS DAYS OF RECEIPT OF THIS . NOTIFICATION, UNLESS CONTESTEC (Sac anoutaUOOkl(t) Th.i Sacuon May Ba Oaicn#o Bator# Polling p|#rctiofl wiin tnn lorm l_____________ ________ Ya4pBfRREGULATION OR SECTION OF THE ACT VIOLATED: DESCRIPTION OATE 8V WHICH VIOLATION MUST BE CORRECTEO () 10-foot centrifugal easting departsesit - pipe roller. Step 1 - Effective respiratory protection shall be provided and used by enployeeis) as an r interim protective measure. * Step 2 - A written detailed plan of abateaent leading to the cooplete abatement of this item shall be subedited to the Irea Director. Such a plan shall: a) employ the use of qualified engineering personnel; b) Include detailed engineering studies and their results; c) outline the ordering of equpnent and materials and completion of the design phase; and d) outline dates for 'die anticipated ^ mpT rm q/ the rrr>. Step 3 -- Feasible engineering controls and/or admini strative controls be determined. Step 4 -- ibatmsit whan Be rwimpT .fwl By Hnpl wriiwwraf^fin of feasible r\----r-tng and/or riwTrii wnurtT. controls and Its effeccLvaoess at achieving compliance verified. 90-day progress letters are requested during the abatement period. (Berrlaed as shown below) uFB 1910.134(a)(2): Hie employer did not establish and main-- n a respiratory protection ptpgnin rh included Thn ri- ta outlined in paragraph (b) of this aectian: Xc the fallowing work areas -- (a) Linkbelt holenan. (b) No. 6 foimdry peraansit mnlH -- iron pmaiT-ing snA f core areas, shakeout. (t) 5-foot cri 11 -- millers, chlppers and gxindera. 3/13/79 --y <5>c? S / ' 5/23/79- 4/30/79 TO EMPLOYEES -- Th, law gives an employee or rm lenunve ine opportunity io op|ect to any aoatement date or a violation it he believes the date to be unreasonable, contest must be mailed to the U.S. Oeoartmeni ol Labor Olfice at the address shown above within 15 working days l0 ' `-nfls and Federal holidays) ol the receipt by .1 this citation and penalty. EMPLOYER DISCRIMINATION UNLAWFUL - Th. law pro hibus discrimination by an employer against an employee lor tiling a complaint or lor exercising any rights under this Act. An employee who believes that he has been discriminated against may file a complaint no later man 30 days alter me discrimination with the U.S. Department of Labor Area Office at the address shown above. total PENALTY FOR THIS CITATION M#heCh#CfcoMon- Ofdtf Piyibti To *`OQL OSHA" latficiii OSHA No on Remittent# _rt RESPONSIBILITIES ANO COURSES OF ACTION -- The enclosed booklet outlines employer responsibilities and >es ol action and should be read in coniunct.u-, -tn mis notification. CITl "'t,HCATI0N Of PENALTY nsnA ? nr v f./7i, CITATION and NOTIFICA '** JF PENAlTV mrcinshon Area Office r; ' 2047 Canyon' Rood '' / mjaingham,- A Inbam 35216 I3 1 TYRE OF VIOIATUWW r Isamus f3 ! Citation issued an 2/23/79 is Amended: TO. The Central Foundry Company Post Office Dox 186 Ualt, Alabama 35401 i ?/24/7Q; Pift&b- 47^ 1 REfilOft _ | ARIA 11 ^ACi A' ^ 0133___2--1 INSPECTION OATE 8/23 - 10/1S/7S INSPECTION SITE. Halt toad Holt, AT nKamo THE LAW REQUIRES thtt coov ol thit CitAiien D ooittd immot*(iy m orom>ntni pic At or ncr tn location ot iim y<olauon(t) cud btiow Tn# Cuauon muit ramam poiiad until trt# violations citad o*low have Oatn corraciao. or tor 3 wotting days (iciuding wminoi and faoarai nondaytl wfuenavat it longer. PENALTIES ARE DUE WITHIN n DAYS OF RECEIPT OF THIS N0T1FICATI0' UNLESS CONTESTED (Set tncioktL. Bookici) Thit Sactton Ma Be Deiecneo Belore dotting cimion unriMi viol.non. cl ih. Occup.uon.1 Salaly .fid HmIW Ail ol 1970. Th. panallviias) lutao o.iow a<a oauo on in... y.oiauoni. moll co.raci in. .lolanon. i.l.r.ao to in mu enaiion by in. data. Imad balow and pay ina panama, propoaad. unla.. iin IS ~or,ns o.y. .od.ng Maa.and. and FaUaral holiday.) Irom your iaea.pi ol tm. elta.lpn and panaliy you m.oa none, ol com... to in. U.S. O.panmam ol ji Aiu Ollic. al in. addra.i Ponn aoova. IS., iha anclo.ad Dooklai which ouum.l your >oipon.ibillii.i and cour.a. ol action .no mould 0. . m coniunction with this term.) ivl NUMBER NOARD. regulation on SECTION op THE ACT VIOLATED: DESCRIPTION OATE BY WHICH VIOLATION MUST BE CORRFCTEQ PENALT Y (d) 10-foot rrtn - grinders and millers. (e) 5-foot cmtrlfugsl casting departamt -- operators, alTenen, cranemen, pipe roller, and core pinners. (f) Linkbelt miller. (g) 10-foot cartrlfagal canting deportment - pipe roller. I DIRECTOR . uyatr : TO EMPLOYEES -- The law gives an amployat or rm iianve the opportunity to obiect to any abatement Pate a violation it he believes the date to be unreasonable, uesi must be mailed to the U.S. Department ot Labor lice at the address shown above within 15 working days EMPLOYER DISCRIMINATION UNLAWFUL - The lew pro TOTAL PENAL hibits discrimination by an employer against an employee lor filing a complaint or for exercising any rights under mis Act. An employee who believes that he has been discriminated FOR THIS CITATION M.h.cnicb.iMe Ord.r Payable t ageinst may file a complaint no later than 30 days alter the QOL OSHA mg weekends and Federal holidays) ol the receipt by discrimination with the U.S. Department ol Labor Area Ollice tntficai. OSha r iloyer ol this citation and penally. at the address shown above. on B.miil.nci IYER RESPONSIBILITIES AND COURSES OF ACTION - The enclosed booklet outlines employer responsibilities and *s ol action and should be read in coniunction with this notification. CITATION AND NOTIFICATION OF PENALTY nsiiA ? nrv sirr. p mrpuj Area Office .. 20..7 Canyon Hnad A1 nhara 35-*6- Serious iUia. The Central Foundxy Company FO Box 186 Holt, 11 3,51*01 orcio* ut* ' 4 I 0350 or INSPECTION date 8/23/78 - 10/1B/7S INSPECTION site Holt Hood THE LAW REQUIRES in*i copy of mu C<i4i<xi M 0eu*a trnmacitiair a oem nent piaco ai or naar ifta location 01 m* ioiaiioaUI ento btiow. Tha Citation mutt iimaifl potiao until in vioianont citco Do le* hava Man cortactao. or lor 3 working oayl including wtaaanot ana f tatr*t hole oayil whicnavtr u longer. PEN Al l ItS ARE DUE WITNIN IS DAYS OF RECEIPT ' OF THIS NOTIFICATION. UNLESS .CONTESTED (So tnciotca Booaifii T hit SicukA Mi B* Omenta Daloia Polling non u.icr.D.. ..OI...OK. ol Ih. Occupational S.l.ry .nd H..IU. Ac. el 1970. Th O.n.lryU.I im.d Below >. o.uo on m>. .oi.,,om. M comet in. 01.1.0m ..I....0 io in mu c.i.iion or in. d.i.i mud Below end pay in. e.nun.i e/opoi.d. uni... ~..n.n 15 ~o...ne o.yi ivMb.noi .nd P.d.r.i nol.u.yil Irom you. > ol mu eii.uon and pnHv you mail t none, ol com.11 10 in. U.S. O.o.nm.m ol ... Ollic. .1 in. .OOI.I. OOM .oov.. IS., in. ancloi.d Doou.l ~nien oullm.l your ...oomio.1.1... .nd court., ol tenon .no moulo Oc aniwnciton with inn lorm.l UMBER ano. REGULATION OR SECTION OF THE ACT VIOLATED: DESCRIPTION 77 OATE ev WHICH VIOLATION MUST BE CORRECTED PENALTY violations described in yM q citation are alleged to have occurred >r about the day the ~iwop<' i i nn was made unless othervise indicated in the description given below. :m 1910.1030(c)1 Employee(s) were exposed to aaterial(s) in ;ss of the 8-hour i-Enm weighted average limit(s) listed for that jrial(s) in table Z--3 of subpart Z of 29 CFR part 1910: 25/80 5900 Free containing dust at the following areas: a) Linkbclt ' Uoleua b) 6 foundry permanent mold -- core and iron pouring areas c) Fire foot pin - millers, grinders, chippcrs d) Ten foot nill -- millers and grinders 1TI 1910.1000(e): .Feasdllc administrative or e^incering controls not determined nnR iopleaenved Co reduce employee exposure(s): ^^X^-efouniry permanent mold -- core and iron pouring areai: fivc^foot mill -- millers, grinders, chippcrs; <S^t foot trill*-- millers and grinders. Step 1 -- Effective respiratory protection tHjIT be provided and i.'jed by employee(s) as on interim protective measure. 3/19/75 Step 2 -- A written detailed plan of abatement leading to the complete abatement of this item shall be submitted to the 5/28/79 Area Director. Such a plan shall: a) Sap!try the use of qualified engineering personnel; b) Include detailed engi neering studies and their results; c) Outline the ordering of equipment and materials and campledon of the design phase; and d) Outline dates for the anticipated inplaicntatian of the plan. , Step 3 - Feasible engineering controls and/or administrative controls shall be determined. 8/23/79 Step 4 -- Abatement Khali be completed by implementation of feasible engineering and/or adrhnistxative controls nm* its effectiveness at achieving compliance verified. 90wiay progress letters are requested during the abatement period. 2/25/80 n. t.- vt-et-t _./v L<rT7 : On Uat . TO EMPLOYEES -- The l.w givts n employ., or hit EMPLOYER DISCRIMINATION UNLAWFUL - The law pro 7T?wpPES7rr nuuve in. oppoiiunny 10 obicet 10 .ny abatement O.ie 1 violation il h. believe! me due 10 be unre.ioneble. inieu mull be m.iled 10 me U.S. Depenmcnt ol Lebor hibit! diicriminaiion by an employer agaimi an employee tor FOR THIS liling a complaint or for tierciting any righu under thu Act. CITATION Miktc An employee who believes that he has been discriminated 0*d< fAvkttt To ll.ee ti me addreu mown above wiinm IS working diyi against may lile a complaint no later than 30 days alter the 'not osha** Umg weekends and Federal holidayil ol the teceipi by ibloyer ol mu ciianon and penally. discrimination with the U.S. Department ol Labor Area Ollice at the address shown above. Ind.Ciie OSHA No 0*1 npmiiUAcr OYER RESPONSIBILITIES AND COURSES OF ACTION -- The enclosed booklet outlines employer responsibilities and v 01 tenon *nd should be read in coniuncuon with this notification. CITATION AND NOTIFICATION OF PINAITY OSha ? nf v c - area Office 2047 Canyon Acad Qiiminghaa, Alabama 35216 ' mcio* ;4 u nci 0350 2 0. 3 1 TYPE OF VIOLATIONCSl iOTATIMU | 1 Serious r 3i INSPECTION DATE 8/23/78 - 10 AS/78 inspection site Eolt Eoad Tha Central Foundry Company FO Bor 186 Holt, 11 35W31 THE LAW REQUIRES inti toov o> Citation o# poiito immioiliiiy m * piom< n*m piece at ot r*agr me location 01 me voiaitoniil cit#0 bttOM Tn# Citation mwii umiiA ooitaa unt<t m# w<ateiom c*ia oeiom neve oeen coriectao. or lor 3 woramo oey tasciuOing v*##a#nai and Feoarei non OayiJ MAicAivtr 11 longer Thu citation oeicnpei violation* of me Occupational Safety and Health Act of 1970. Tha p#n*Myl.il luted oaiow are oetau on male vioieuoni You mu*t correct the violation! related 10 in thu citation oy tha datai luted batow and pay iha panamas proootad. umaii wiimn lb won109 day* (excluding waaaandi and Faaaral holidays! from your receipt oi this cuauon ana penally you mm a none# o> contcu 10 in# u S. Ooertmni oi uaoor Art* Qllvca at tha aoorau mown aoova. ISaa in# anciosad booklet wftten outlines your responsibilities no couri#i ol tenon ana mouiO D read in coniuncnon wnn mu lormJ ITEM NUMBER STANDARD REGULATION OR SECTION OF THE ACT VIOLATED: DESCRIPTION 1 DATE BY Which VIOLATION MUST BE CORRECTED - lc b/30/79 Z9 CTR 1910.134(a) (2) t The asployer did not establish and o&ls- -tain * respiratory protection progran which included the requirecents outlined in paragraph (b) of this MCtUe: j ! j SC) In the following work areaat i CS> linkhelt _ . . Holman i __ ^ #6 foundry permanent maid, inn pouring and core areas ^c^uerS7 C Tire foot bLU -- Billers, chippers and grinders _p Tea foot mill, grinders and niilera. Id 29 CFR 1910.134(b)(1)! Written standard operating procedures governing the selection and use of respirators were not established: (See Iteu lx(a) above). le 29 CTO 1910.134(b)(2)t Resplratoris) were not selected on the basis of hazards to which the worker was exposed: (See Item lx (a) above). If 29 CTO 1910.134(b)(3): The users of respirators were not instruct ed and trained in the proper use of respirators and their limita tions: (See Item lc(a) above). lg 29 CTO 1910.134(b)(4): Where practicable, the respirators were not assisted to individual workers lor their exclusive use: (See Item lc(a) above). lb 29 CFn 1910.134(b)(5): Respirators were not regularly cleaned and disinfected: (Sec Iteu lc(a) above) li 29 CFR 1910.134(b)(6): Respirators were not stored In a conve nient, clean and sanitary location: (See Item lc(a) above) lj 29 CFR 1910.134(h)(7): Respirators used routinely were not inspec ted during cleaning and worn or deteriorated parts replaced: (See Iteu lc(a) above). " AREA OIRECTOR ---- ------------------------------------------------------------------------------------------------------------------- C. 1. UTATT ---------------- .On U NOTICE TO EMPLOYEES -- The law gives an employee or his fepresentativ* the opportunity to ohiect to any abatement date set for a violation if he believes the date to be unreesonable. The contest must be mailed to the U.S. Department of Labor Area Office at the address snown above within IS working days (excluding weekends and Federal holidays) of the receipt by the employer of this citation and penalty. EMPLOYER DISCRIMINATION UNLAWFUL - Tha law pro hibits discrimination by an employer against an employee lor filing a complaint or lor exercising any rights under this Act. An employe# who believes that he hes been discriminated 9nit may file e complaint no later than 30 days afier the discrimination with the U.S. Department of Labor Area Office at the address shown above. EMPLOYER RESPONSIBILITIES AND COURSES OF ACTION -- The enclosed booklet Outlines employer responsibilities and courses o! action and should be read in coniuncnon wnn this notification. TOTACTfc FOR T CITAT Order rvi Doia. Aeicm OS on Ramu CITATION ANO NOTIFICATION OF PENALTY CASE FILE COPY OSha 2 RE w - pi Arta Office 2347 CjUTDR Road rs win. npnii[ M n*^31"^ 35216 1 TYPE Of VIOLATION! 1 citatum sa. | r !3 1______ Sit* niu_____ ! .2/23/79 ynttiOk .4 i Picao- 175 1* AM A * MCI 0350 3 c 3 8/23/73 7SINSPECTION OATE.q/iO / INSPECTION SITE liolt Road ro The Central Foundry Company PO Box 1B6 Iiolt, AL 35401 THE LAW REQUIRES tnai a coov 01 mu Citation Pa pouad immaoiataiy 10 a orom> nant piaca at or naar in# location 01 tna viotationUI cuaO Paiow Tna Cnauon muii tamatn pouad untu tna vioiauom cuto oclOw ftava Oaan corractao O' to' 3 womng days iaaciuOmg wraaaanoi and f aoarai hoirdayil **fnchaar 11 iongar ............. a.*,*.. ,,.oi.,.oo. or in. Occup.uon.l S.r.'y .no Hr.h Ac. or 1970. Th. P.n.i.yl...l .....a Miow ... -o.-c.ocx. ,, muII cor.:i m...or.non. ..t.rr.o 10 .n ihn c.i.iton by !>. a.ilud Mlow.no or/ in.p.n.m.i propoud. uni.u w.imn 1 s wo/.m8 o.v. ttuOtng W....nc?.nd F.0...1 nol.o.yil Iron. you. >P < e>on .no P.nWiy you m. . not.c. or con.,., .o m. U S. O.o...m.m of JO, a... Ollic. .. .h. .adr.u down .uo... IS.. <n. .nc.o..d book!.. wmcA ouU.n.. your ,,,pon..b.ll.... .no cour... ol .con .no mould o. PENALTIES ARE OUl- WITHIN'^' DAYS Of RECEIPT Qf THIS KOTIf (CAT UNLESS CONTESTEC {Sa cnciatiBooaki Thu Sacnon t 0* Datacnao Batata oiun. VJ.S.OEFARTMENT OF LABOR WORKSHEET CSHO NO 02. R* Ort NO. A"^.V l -> U/ > IMS Him No. 1 T* e-w\ PiAVE ,oio,,7 1 Ne^o ^ 3. Oilt/Timt 2l|s|-^ ^ 4# TyP 1 40. Nu'rt*>*` ' *gt r*. -=S 1 3 o p 7. Siinoi^i Aii*f#otv Violated \ . iCftOfcft fl. Atoattmant Panod > ` Paou-vOxGLa-n V-aoLT C- 1 9 No.oMnsi i 1C Rt P? To R*(. No. Kj_r ---------------- -- -- L. AVD/V.,,.1. .n.,m.,..n. . ------------------------------------------------------------------------------------------ -V<-> caiemiNib t oc.A--noiMS_ J3rd--f.myQP-ki ^ ' A ^ ."^T^T ~--g&g-.lCiLri-S )--, p> lLV ' \,M WlA w IVvA. VTV.oVfl t&Au.aJ ^,T-..,' fv\_rrNA iJsO n r____ e ^fPCT ~) - \\ rg v~'-n(X ,,.l^ UkcA\a.'>^'1^ C\ ~L.lC'\t : T \ lu.i *ht' \n^_ lVj^C Ox r~~r~ .?ri^U-- V _Z1__1AJ2_ j^yH.\ ft. f \ ) Corn ^NG-k -G-l-C-C \\\ M_M***- 3C, ,\,X v <\rT\u \ ^LckF-* -4ttn ,/.'lr Gm<-, V\ l Ci<i<2_ Miiiurifflimi. in - vXe.-^- (9v>^VZm> <, .f f tn iV-Ou,> U- x. 'VV^ \U ^ PV^ ---At*-*'< 'U> >< ___ x~filA' 13. PHOTO VQ, t^P) Icarwv CUPy> ] On r&^Tt cV nCxirj-iTrv. o-^ -K/ A-AtA 1 - 1 a OccuoatlPn l& Emolovtr) 1 b. No. c. Total Duration 1 >4 d. Fraouancv '.vvT..nMy.Uu, ITP nr- 1-11 I'JTrU | I a. Esoosad Employ#* -- Nim*. AdOran A Phont 3r> "i <oA^Sac\ pnSt: ~'=U<5k -- ^C;\ \\ o Ui -- - -- -- -- ------------ j Coni'. LMFLOVFRKNOWLEOCE-pju:^^, uT^X V- ^M'COn COMMENT:S (Emo<ovir. Emoiovt*. Closing Coni.I <^0. x-U^-l OTHER EMPLOYER INFORMATION CLASSIF.. jk O'| ! ; t a. Proto. o lniwry/|li. . Qr to. GraviiV'Gatad z . No. C*l. 0l Uncorr. Ui o. P,B,,, c. Tlmoi Raoaatod/ Dagrit 01 WHIM d. Adluitmant Facton 11 Slit ! 2) Good Faith i 3) History CI -------------- ---________________ :___________________________ :___________________________ (_ /_!; 1 'I A-T ---------------------------------------------- 41 Total |t. Proooiad Adiuitpd Ptnaii 1 form OSM A \Zj!. -Ol_VX \ v'A'A >X.\. .AH. TOP t \V N-lLr/^-.V. V-- A-S CJ^ "AA'i. t' ^y.\ Uw (<*.\. <0.1X'>' V" IrlH 7( 7'>. IQ- A'ao^a-Ha... --../.,...>3A_ Aj .S.JC Aw.Ll.| . A_\V-o_. vx>.,v. xA\**sv\ A\L_vvyA\\___vy.AAjix \, J-Av "Jy^^rA.vOV w. Oj n.'-_---a----A\?---.---C----W-----.--I-----_-\A.\.s*;%' ,..J.^r.t,' Lr\GlI--___ <-d.'-. - - V 7A\\&\7*<> ) 'P'IlA.uI<Acrvv_.._\/:fj_i A Q-.^v^ -r-.`\.lTr>V' --~r\- A?--.,VJuc..`l_. A l-ii. A --v. > < U.> ^-Ca. ^ -vA A . \ \. V :. \0- i ' ^ A\ _>'\vAa* '_H 1 ---- ~St~ A ____ -- ' ' \\ " - ' _ i,,\ A V \. / a o-y ""s "A- y .1,. \ . A^AcAoL'ii AAAaLc . a> Att A* ?v'rNu^ A__TM A -Cow~~Av Sr- I:tt'\~L)_.^c~ vl Hqj ^ \ U*"V 1\ ' LZyLo\ .-^c>(Lo.__ ALc A - H-A I/wws.'lPV i-Av \r\ -\"'0<.~>\l__ C't Jjatoi-A.___1 A-'--^\- sA^lA)_----------------------------------------,:_. u. ______?^)~pg 'V. <A > > -V.\ t c - A. puiAv^xA-^. ^V-1 lA-itlJk.. c^g.___________c Cv.I^.-vIcjA;. -V^ ,j <i^-\ Atvt'ow---cgp- a-- ------------------------- -D~)V \ 0- V./I.fl'l -A*. cH.\ '7. G-vf C. cA Li x \ f 11 TrN \it\hi_, A-'H ^&Wr\r . jL.ula -- ^ uSiskA-Hr yC<? siUv^-^iW Cl-nkV t AA-U-yw IrO-jk^iM___ o(aa\uV lAv-I-V AA, tw, > A/W A-viHI____ AxAiIl- UtfvA_(gjggajj)____ ~^rA_T ?.V-14^____ AlALx i - " .r72.x\A *Jouw" ZfLiiS-,.47/j. V IAS~ . -V2_ ...________ _Vi*iWtLu^_______ 72? tC" ^:n _22? -2'P ^"3^2. A oTS~ - 1 iiS! .fl/ y_ lJ:J- ,,;.9kJ __________ HI A__ _________ 13HH. \ -2 (^3 -- tx.,;UOt-*' *'- _IHO i 'uUo^ . -- _H__oo LX;^w 73 23 3<^ q > i A\" ...Jiil_. .Tl ___ ____v .'.lAv- ? 3^ 2 A7^-1^__ 3SS n ( 2\ .^IL- v___\ .2s (gCJ>/\ i_AL' .1.12:______ ________5v\ \j I t) Luo> \ . ___O"l0 kt,,. cT TH.IV.A C-)- 1 \ --* IV It? ii-n i i-io 23-^| 7 V13 'AiOSJ.!' V/.J ->-X(g "Ix^lT______ 3 ctTvifti-. A/v-U ..H'is. (. 03 ,2A2- . ,n"> . "1 GjA ,^ ,3^3 .31 b 713 * ,~)\ .737___JUlUt u. -_,U021_ .HU / '/V : l .3^^ jf *7 S - 1 OW .7$ .211 * .7 S' :^:l_ .(73 \.ois n H's ,7Al . 7115 V 7 S' .loTl ^ u o WT A V'O 'O.Vi^'i'.' ri c.j in fiWHiN- 'V.r U"t nl/5. iaIi ^>' V"Volc ti.-I' A\ mT o\aA7i )rv\ srin^oTtl 0-id Lx. AoAaV '(Aa^V. ^.WST- . cA\?.\ il-i A cAv, y < L*: c'}^\ vO.'.S . WORKSHEET CSHO No. auAftA- \ > 2- . R--#--o-o--m--N"o 3. iOmi/|Tim A 4--7 S ^li^hq--i!-" 'V 6. liuiinu -- I 7 Sionbon* All*9*OIV Viomoo I \DOO(e.i 14a. Tyoa | 4D. Numor | I 8. Aoaitmam Panod '"T -3 .N..c. oi mi; 1 ^ . SAVE tO Coot ^ cr-*\ Li T0 Rtl. No. 0. AVO/varioWa taiormanon. An I CW*riP <=rv-v 'U ^_ C J-jTi- '`i^ ----- <* \ r> iprXyTT *v> e^v~Y -- mri; ...... .rv<n s . '^v^n \ ^rA^rjZLw^s^ynry\Qrv A -L0^ ^ :. XviA^XJlC^. \,ro< y^~ **> | -t'|l~'^ - *4^. X,, <nn \ JLI ----'.-Xk-rrv'fT' i- IT VCV Cc^^ tv.,->,rl-; ca \j Coni w INSTANCE DESCRIPTION la. HiMiCiOwi./Cona.-Aec.; B. EouiO.JC. Loeotion; nO d. Iniuiv/W.l 4^\ &s^-^.Actva,-(^oo cx.vc- nr/~-*v\ Ac*-* Xri-ex> *S>.-Lfr, X-cr~\ .A vX -;aa^VjAC " A. H\ f o-- Lai*:. IT-v-C CJ*~^ O A u>n^i.-nJ- \r`g-G- v--__ 'wvw-^AVMj, L^r....r7rTeek^V Co~>s iaq W ^A .X -eE) t^A a :Q a,'ES rr^~ _irm \____ Aa c a?* '---> fcA AolVc/v Ao~QarV~. X<r~i \r^~ A-c.C. V irV XC\ O^'bcx-'.' CV* >vA!?X*v ^\ EM^OY.RKN^EDGE: \Xvr7\ ,A^C^r\ VX 5 COMMENTS lEmotovtr. Emotovaa. Doling Conf.l ilcAn^ t1^ ^ X cr. vT-uVA-C/vy' j'"" Corn'd 1 OTHER EMPLOYER INFORMATION Com d B CLA,,F.. r-- --- "7-- r"^,TN? , I a. Prod. Ol Iniury/lll. j\ or i lb. Gfivuv<&aitC i ., No. C.I.O.V. uncoil.! P,n,U* I * c. Timti Rapaatad/ I O^r,. 01 Willlul _!--^9lVMmnl factor. _ia. PlODOItO "" Adiuiud Ptnaiiy 11 Silt I 7) Good Faith I 3) Hmory i 41 Total \ my-- i.T.n. ,L v.> ( o.^ <*,, .v, ^c,r,\ Poim OSh A-U: Ot^A^TMfcNT Of LASOn WORKSHEET C5MO N. aun?,4 7 fi.BOfl NO anq ; 3. D*it/, Ttfn ' -^'1Q |. U )4*. Type It ' 40 Numo' .3 r nam No. \C SAVE tO Coo* ,* 6 imtanca fs/ CT^\ U-> o. 3 A- oMO1 I 7* *Siiii/filooairrod Ail~9j ^fO.Wiv vVtiooltamtefdl.. vI <n \ \ . Ao*|m*n^Pftoa . \aAj-\gv.igW' T0* ft** No rv C~r\ tS o. AVO/Van*o*e miormauen. 9 No o > > m t. i 1C RE S C\ . occa^at-wnC fcx~v vcxw<v ^ S' C Uc V w^e^C'I~ -- D~^>C^oA. C~'t to A l/W uXit* rp=-gw^?g 4) \vS> 03* -T3--3C*"J_------iCEaaC* NSTANCE DESCRIPTION I*. HuorOl-Ooor./Cona.-Afl.. B. eouie.ie. _l_o_c__a_t_i_o_n__:-A.n-!^--a. iI_n.i.u.^P\y^ItIiiUi , ---------TC'-^l ' M \L-H-1 io.t,,ZXig~ti,t--r*y' ------l-.--*--)-------N- ---o --;--e ^ iA A i. -tt 'Ac--;1 -Vc. IvfrssV - At i V_Ps ( s x ------------ -------------------------------------- . <r'\\Aik. CV3^a-. ocV^eX-pi f Ay,C jAurrsl. ~`30v~.-hWlV \ 3Fv^^riv ^ t -W~\ \aW o-- A OTHER EMPLOYER INFORMATION I Coma CLASSlF.. T ------ ---------------------------- w_< l 7 IMBM N ['^JaS0'"i^"Mi* i\WJ'Jl| z. * Proo. ol tniury/lU. Or l>. Grevnv8aied z * "No, Cal. D*vt Uncorr. Penalty \ c. T'mt FUotatad/ 1 Deqrte 01 WiUlul j 1 1 11 Silt a. Adiutifncm Factor* ' ?) Good Fnh i 3) Hmorv 4) Total i Prooottd AJiwittd Ptnaliv V ..' . . -JO . i r ,. i May 23, 1979 Th<. Central Foundry Company P. 0. Box 188 . H$lt, AL 35401 Per your request, I am listing the silica sample results we obtained during our inspection at Central Foundry: DATE JOB SILICA MAX. PERMISSIBLE ACTUAL LEVEL PERCENTAGE LEVEL PER mg/m3 MEAS. PER mg/n3 10/11/78 Sprayman Machine Operator Sprayman Craneman Pipeloader Valveman Shakeout Muller 10/10/78 Muller. GolecurhHoleman Shakeout 10/6/78 Core Machine Opr. Core Machine Opr. Weight Changer Ueight Changer Molder Miller Machine Operator Bench Molder Core Machine Oper. 10/5/78 Shakeout Holeman Shakeout 10/4/78 Molder Core Mach. Opr. 14 56 22 24 24 21 16 29 18 25 9 20 4 5 5 2 12 5 2 7 6 13 8 29 1 2 .625 .172 ' .417 .385 .385 .435 .55$ .323 .500 ,nD .909 .455 1.667 1.429 1.429 2.5 .714 1.429' 2.5 1.111 1.25 ,, .666 1.0 .323 3.33 2.5 .536 .221 .286 .550 .506 .400 .158 .255 .674 .700 .567 .124 .825 .811 .494 1.494 .204 1.239 .737 1.013 .395 .463 .973 .511 .123 1.491 1901 J Hr. Joe Sledge - 2- Hay 23, 1979 DATE 10/3/78 9/27/78 9/20/7S 9/7/79 3/31/78 2/15/79 2/16/79 SILICA MAX. PERMISSIBLE ACTUAL LEVEL JOB PERCENTAGE LEVEL PER mg/m3 MEAS. PER mg/m3 Grinder Sprayman Pipe Loader Set-up Surface grinder Core Machine Oper. Machine Operator Iron Pourer 13 17 33 19 15 14 33 15 .666 .526 .286 .48 .59 .63 .29 .59 .332 .286 .627 .297 .194 1.115 .777 1.36 Miller Miller Miller Wheelabrator Oper. Grinder Chipper Chipper Grinder 23 38 37 24 18 42 25 21 Grinder Grinder Grinder Miller Inspector Grinder 22 35 32 36 21 30 Operator Shakeout Valveman Core Pinner Sprayman Operator 9.2 11 16 19 14 17 Pern. Mold Shakeout Linkbelt Muller 15 9.4 .29 .25 .26 .38 .50 .23 .37 .43 .42 .27 .29 .26 .43 .31 .892 .769 .555 .476 .625 .526 t .588 .877 .407 .489 .397 .260 .277 .499 .532 .296 .604 .316 .462 .412 .238 .245 .316 1.263 1.015 .807 .728 .876 .071 1.399 If we can help interpret these results or be of any other service to you. please let us know. Sincerely, C. L. UYATT Area Director CS/lp IN THE DISTRICT COURT OF HARRIS COUNTY, TEXAS AUGUST GORDON, et al., Plaintiffs, 30B SCHMIDT, INC., et al., Defendants. ) ) ) ) No. 93-42852 ) AFFIDAVIT OF DARIN V. OSMOND Before me, the undersigned authority, on this day personally appeared Darin V. Osmond, who being duly sworn, on hxs oath, did state as follows: 1. I am over the age of 21 and am fully competent to testify as to matters set forth in this affidavit. 2. The following documents, which are attached as exhibits to Borden, Inc.'s Motion for Summary Judgment, are true and correct copies: "Exhibit C": Central Foundry Plaintiffs' Answers to Interrogatory No. 6; "Exhibit D" Excerpts from Deposition of Wightman M. Cannon, Jr., "Exhibit E" Excerpts from Deposition of Robert Yaw; "Exhibit F" Excerpts from Deposition of Billy Don Kizziah; "Exhibit G": Excerpts from Deposition of John Paul Singleton; "Exhibit J": Texas Occupational Health Regulations, OH-13-2 (1958); "Exhibit K": OSHA citations and records related to Central Foundry (identified in Deposition of Billy Don Kizziah at 192-20: (Exhibit F) SUBSCRIBED AND SWORN TO BEFORE ME. the undersiened authority, on this the Q_.. day of April. 1998. to certify which witness my hand and seal of.office. LISA FIORENZA Notary Public sun op nxAi My Comm. I*p. Nov. II, IW NOTARY PUBLIC fcFAND FOR THE STATE OF TEXAS ~ --LlI____ l____ L My Commission Expires: MW/l 17194 -2-