Document 4JJw4eX94njyeaK1wmyQJznbR

INDUSTRIAL- HYGIENE FOUNDATION OF AMERICA, INC. -4400 FIFTH AVENUE PITTSBURGH. PA. REPORT OF INDUSTRIAL HYGIENE SURVEY MADE FOR Uni.ted.States. Asbestos.. Division of .......Raybastos-^anhattan,. Inc......... ...........Uanhein, Pennsylvania........... March 14,15,16 and 17, 1944 '~1/J C - ^ -- FIELD WORK BY............... Ventilation Engineer LABORATORY WORK BY Industrial Hygienist h.D...,.,, April 18,.. 1.944 Industrial Hygiene Foundation of America. Inc. MANAGING DIRECTOR / J ' / INDUSTRIAL HYGIENE ROUNDATI ON OF AMERICA. INC. Industrial Ventilation Survey of the United States Asbestos Division of Raybestos-Manhattem, Inc. Manhein, Pennsylvania March 14,15*16 and 17y 1944. STEWART This is a report of a study undertaken to locate the most impor tant sources of dust and to develop additional dust control measures at the ilanheim plant of U. S. Asbestos Division of Raybestoe-Manhattan, Inc. Sixteen dust counts were made in various departments* These samples indicate that conditions in the Picker Bouse are not satisfactory but dustiness in the Carding, Spinning and Twisting Departments is less than 5 million particles per cubic foot* Recommendations are made that can lead to a reduction of dustiness in the Picker House as well as in the Carding Department. It is believed that while the card room is under considered!* negative pressure the consequent starvation of the exhaust equipment is probably not in itself sufficient to account for any markod reduction in control of dust. The results of dust counts are iven in Table I* 00460 INDUSTRIAL HYGIENE FOUNDATION OF AMERICA. INC. Industrie! ventilation survey of the U.S. Asbestos Div. cf Raybeatos-ilenhattou, Inc., Hanheim, Pa., Jfarch 14, .15, 16, 17,1944. TABLE I Dust Counts 2 Sample No. Date Time 24 3/14/44 1:50-2:01 P 27 3/14/44 1:35-1:45 P 21 3/14/44 2:16-2*27 P 19 3/14/44 4:22-4:33 P ESP 10 3/17/44 9:5C-10:42A Location and Operation Picker House At Pan Crushers, to nearly simulate operator's exposure Floor Batching - Exposures of 2 workers outside booth - Finished about 1:42 Operation of Pan Crushers for AmositeTine represented complete cycle of operation* (l/2 hour daily) Batch feeding vertical opener. Ex posure of operator within booth 52 minute sample at contral point of room for "general air." near vertical onener Particles per cu. ft. 8,7 Million 1,7 million 38.0 million 9.9 million 5. 6 million 23 3/14/44 2:59-3:10 P 26 3/14/44 3:17-3*27 P 1 3/15/44 10:54-11:09A 2 3/15/44 11:15-11:25A Cardirs General air walking about various carding machines in Breaker Card Room Besido point of discharge from con denser to box in Breaker Card Room At roving end of 4 finish cards, ?1, 2,7,8. General air - Exposure of 2 attendants Along central aisle-way, at camel-back ends of cards 4.'0 million 3.3 million 4.3 million 4.8 million ESP 11 3/17/44 10:49-11:49A Between finisher cards, #15,16,21,22. All windows of carding and spinning room open wide to simulate summer con ditions 2.8 million 3 3/15/44 11:46-11;5SA 4 3/15/44 1:10-1:20 P 5 3/15/44 1:36-1:46 P 6 3/15/44 1:50-2:00 P 7 3/10/44 2:19-2:29 P 8 3/15/44 2:45-2:55 P Spinning and Winding At mule spinner, while following oper ator, to simulate his exposure A.t Universal winders, 2nd floor, ad joining cards - following operator f no exhaust) At Foster Hinders. Average of nil aisie-ways At Twisters. Average of all aisle-wavs At D-fr.vmes on 2nd rloor. Average alorv; aisle-wave At L-fxemos on let floor. Average along nlsle-v/ays 4.3 million 3.0 million 3. 6 million 4.0 million 3. 6 million 2.0 million Note: All samples with liidgot Inpinger except those marked I8P (Electrostatic Precipitator.) INDUSTRIAL. HYGIENE FOUNDATION OF AMERICA. INC. Industrie! ventilation survey of the U. S Asbestos Dir* of Raybcstos-llanhattan, Inc., Uanheim, Pa., Llarch 14,15,16,17, 1244. 3. DUST C0I7TP.QL IK THE PICKIR EDUSE Operation of the pan crushers results in excessively high concen trations of dust as shown by Sample 24 (8.7 million). It is recommended that the system originally designed, which contemplated keeping the doors of the enclosure closed most of the time, be supplanted by the following arrange ment: Exhaust from each pan crusher hood a sufficient volume of air to create a velocity of 200 feet per minute through one of the two working openings whose dimensions should be reduced to 2& feet wide by 2-k feet high, it is suggested that inasauch as the two openings would never be necessary at any ono time, doorway covers be provided that are interconnected so that when one is opened the other Till close. The covers might be hinged and their closure motions connected by cable and pulley or they could be slidable vertically and similarly interconnected. In any case a snug fit is unnecessary and should be avoided for ease in manipulation. This plan vrf.ll call for a total exhaust capacity of 5000 c.f.m. for the four crushers. Patching J- The dust count8 of Samples 27 and 19 indicate that the two workers stationed outside the booth are not exposed to important dust concentrations but that the nan who feeds the vertical opener within ths booth is exposed to concentrations of about 10 million particles during the actual batching by the two non outside. Uio average exposure, of course, is less than this because of the inteimittent nature of the operation. 004605 IfNCUSTRIAL HYGIENS POUNOATION OF AMERICA. INC. Industrial ventilation survey of the U. S. Asbestos Div. cf Raybestos-Manhattan, Inc., Manheim, Pa., March 14,15,16,17, 1944. 4. It is recommended that consideration be given to the erection of a "batching bed" comprising a long narrow bin, located in the position where the pile is now cade on the floor. This bin would be enclosed end exhausted and have as an important element, a sid6 facing the opener that may be removed or shifted by raising when the batched material is ready for feeding to the machine. Further study will be given to this at the time of the next visit. The arrangement i3 illustrated diagranmatically in Figuro 1. Tandem Vertical Ononer This unit was not in regular operation at the time of the study but it was apparent from a brief, specially arranged operation that con siderable dust leaks from the cast iron cover located adjacent to the con denser. It should be possible to correct this without the application of exhaust, either by replacing the cover or by providing an adequate gasket. The giant cutter, Johnson's grader, waste machine and willow were not in operation at the time of our studies. 00r\ 4.* C* oO :': INDUSTRIAL. HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of* the U. S. Asbestos Div. of Raybestos-Mahhattan, Inc. Manholm, Pa., March 14,15,16,17, 1244. 5 DOST C0I7TK0L IN CARDIES Studies of uncontrolled dust sourcas around the carding machines disclosed the following; Peed Bolls An appreciable amount of dust originates at the feed roll of many of the finishar cards, which can best be observed with an intense light beam. Some machines are equipped with curved trays or bsfflos under this roll which are effective in minimizing dust at this point. Observations on this point, made on somewhat less than half of the machines, are as follows: Card 176. Observation 1 OK 2 Pair (but needs front to complete enclosure) 3 OK 4 Dusty 5 OK 8 Dusty 11 Dusty 12 OK 19 Dusty 20 OK 21 OK 22 OK It is recommended that such baffles be installed on all finisher cards not now equipped. This point was discussed particularly with the card room foreman. 0C4o87 INDUSTRIAL. HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the TX. S. Asbestos Dir. of Raybestoe-Maahattaa, Inc*, Uanhoizn, Pa*, liarch 14,15,16,17, 1944* 6. Wiper Roll and Rub Apron Another dust source is at the junction of the wiper roll and the doffer. A partial check of machines was made with ths conclusion that an appreciable eaount of dust occurs at this point in the case of the following finisher cards: Numbers 3, 4, 9, 10, 17, 18, 3, 24* It was noted also that some dust originates from the rub aprons and since these are adjacent to the wipor rolls it may, for purposes of control, bo considered, the same source of dust* It is recommended for the top set of rolls that a removable cover be provided clear over the upper set of rub aprons thus, in effect, extend ing the present exhausted enclosure and rendering this dust source subject to the influence of the present exhaust* It may also be advisable to re move one stave at the lower end of the existing enclosure immediately over the doffer roll to facilitate air flow through the supplementary enclosure. For the lower rub apron and wipor it is recommended that some experimental work bedoae on a hood as suggested below* We illustrate in Figure 2 an exhaust hood or slot which is designed to be placed immediately adjacent to the wiper roll at the point where It joins the rub apron* In the design illustrated an attempt has been made to reduce the width of the hood to the smallest possible dimension in order to avoid interference with proper functioning of tho machine. In this preliminary design we provide for: C04680 INDUSTRIAL HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the U. S. Asbestos Div. of Raybestos-Mafchattan, Inc*, iianheim, Pa*, March 14,15,16,17, 1944* (a) an air flow of 75 c.f.n. per foot of length, (b). a face Telocity of 2000 foot per minute (to aid in effecting good distribution along the length of each slot section, and (c) elimination of excessive cross sectional area in the transition section in order to maintain adequate velocities for the transport of material* A partial compromise has boen incorporated in the design to avoid a too complicated hood but it is believed that the lower velocities at the largest section of the transition vail not seriously interfere T.ith its proper function* Not shown on the diagram are necessary pieces at the ends which will extend to the side frenes and serve to support the unit in position* It would be advisable to have a quichly detachable connection with the branch duct that will lead to the exhaust main overhead* Reserve Exhaust Capacity The following observations indicate that there is adequate exhaust capacity for the supplementary exhaust hoods described above* The capacity of the exhaust system indicates an average of TOO-SOO c*f.m. per oylinder* Some individual measurements of air flows in difforent branches were made by means of static suction measurements-and with the dampers in the position that had been set by the operators of the carding department* They indicate what was considered adequate by the operating personnel as judged visually. As may be seen from the results in the follow ing table they vary quite widely* 004S80 INDUSTRIAL. HYGIENE FOUNDATION OF AMERICA. INC. Industrial Ventilation Surrey of ths U. S. Asbestos Dir. of Raybostoa-^enhattan, Inc., Uanheim, Pa., March 14,15,16,17, 1944. 8. Air Flows Through Individual Cord Eood3 (Taking Damper Adjustment as Found) Unit Static suction Air Flow #1 Finisher #2 Finisher #2 Breaker #3 Breaker #3 Finisher #4 Breaker #5 Breaker #5 Finisher #31 Breaker 1.9 inches 1.0 it 0.6 it 0.8 n 0.4 n 0.2 n 0.6 n 1.6 tt 1.4 n 920 c.f.m. 670 it 515 it 590 420 n 210 it 510 tt 840 tt 790 tt It is particularly significant that even in the case of #3 Finisher and #4 Breaker no escaping dust could be detected at any point* This indicates that there is considerable reserve capacity. CC4Su0 INDUSTRIAL. HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the U. S. Asbestos Div. of Raybestos-Manhattan, Inc#, Manheim, Pa., March 14,15,16,17, 1944. g AIR EXHAUST AHD SUPPLY IN VARIOUS DIPARSUNTS Picker House Kith all doors and windows closed, as is the case in winter, the Picker House v.-as found to be under a negative pressure of 1/2" water column. While this is likely to starve at least some of the exhaust equipment we believe the dust sources enumerated above are of much greater importance than this factor and should receive prior attention. A tabulation of exist ing exhaust capacity from this department is given in the table below and is based principally on the measurements made by Hr* Bertelot and Mr. Gilpin. Exhaust Capacity in Picker House Unit Capacity Old Shaker Screen Cotton Machine Willow and Tandem Vertical Opener New P. & S. Grader, through condenser over shaker screen New shaker screen, through condenser in card room C.O.B. 15 Pipe to Breaker card systea, from pan crushers, etc. (estimated) 2500 c.f.m. 2900 C.f.m. 6000 c f.m. 3400 c.f.m. 2900 c.f.m. 2400 c.f.m. 2500 c.f.m. Total 22600 o.f.m. Unbalance in Card and Spinning Department The measurement of air flow from the carding exhaust systems together with other data obtained from Mr. Bertelet is tabulated below to indicate the total volume of air exhausted from the room. 0 0 4 S 91 INDUSTRIAL HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation surrey of the U. S. Asbestos Dir*, of Raybestos-Hanhattan, Inc., Hanheim, Pa., Harch 14,15,16,17, 1944* 10 Cards 1-12 Cards 13-24 L-franes (older system) L-frames (newer system - estimated) 18,000 c.f.m. 17,000 c.f.m. 13,000 c.f.m. 13,000 c.f.m. Total 58,000 c.f.m. The available data for the breakercard room are as follows: Right half (double fan) Left half (double fan) Prom Picker House (estimated) 6.500 c.f.m. 7,900 c.f.m. 14,500 c.f.m. 2.500 c.f.m. Net from breaker room 12,000 c.f.m. . Some air is supplied to this floor from the first floor Carrier system but there is a deficit for the carding and spinning department of about 32,000 c.f.m. There is, however, an air supply unit in this department with a capacitycf 36,000 c.f.m. which is operating at present as a heater only and requires modification (brought out by Hr. Bertelet) to penalt it to handle outdoor air directly. The necessary changes should be effected. The same is true of the breaker room where a unit with a capacity of 18,000 c.f.a. requires modification to penait it to supply properly tempered-tJvtdooi* air to the room. Effect on Dust Control Pitot tube measurements were made on one of the main pipes with the windows open and with windows closed. In the former case the velocity was 3100 feet per minute and in the latter case 2970 feet per minuto, a ratio of 1.05 indicating a 5# increase in air flow. These measurements are not considered exact* 004092 INDUSTRIAL HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the U. S. Asbestos Dlv. of Raybestoo-Manhattaa, Inc*, Llanheim, Pa*, March 14,15,16,17, 1944. Tho characteristic curve of the fan (American Blower Company, steel plate fen, #30, at 662 r.p.m*) is shown as Figure 3 and as may be seen from the analysis indicated thereon, an increase in air flow of 10 to 15# may be expected by reducing the resistance by 0*4 inche3. One would hardly expect material difference in the operation of the exhaust system with such a snail percentage increase in air flow* Du3t sample ESP 11 shows a concentration, with all windows wide open, of 2*8 million particles, ss against concentrations of over 4 million (for example, sample #1) taken two days earlier. If this comparison is to be considered representative it must be due to the additional general venti lation caused by natural air currents through the open windows* That is, in warm weather, with all windows open, a volume of general ventilation in addition to that caused by operation of the exhaust system will be obtained and must affect th9 dust situation favorably* This would not, however, indi cate marked improvement in winter by providing just the proper volume of make up air* Such unbalanced conditions are always likely to cause discomfort because oftdrafts that occur in the peripheral areas of the room, so it is reconawaded that correction be made* G04893 INDUSTRIAL. HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the TJ. S. Asbestos Dir. of Raybestos-Manhattan, Inc*, Vt&nhaim. Pa., fiarch 14,15,16,17, 1944* 12. TWISTING BSPARM3HT No conclusions were reached with regard to improved dust control in thi3 department but data on the exhaust capacity and volume of air supplied by the Carrier systea is reported below* With the assistance of Hr. Bertelet and Hr. Gilpin v;o made 64 readings of linear velocity at the face of the pre-hcater, whose area is 61 sq,.ft., and concluded that under conditions then prevailing the system was delivering 0,000 c.f.m. A capacity of the various exhaust systems has been estinatod by Hr* Bertelet as follows; Poster Winders East Fan West Pan Twisting Hechinea North Fen South Fan Con Winders Total 3300 c.f.m* 33.30 c.f.m* 11000 c.f.m. 11000 c.f.m. 5000 c.f.m. 3300 c.f.m. INDUSTRIAL HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the U. S. Asbestos Div. of Raybestos-Uanhattan, Inc,, Hanheim, Pa., March 14,15,16117, 1944. 13 RECAPITULATION -- AIR EXHAUST AND SUPPLY Total Exhaust O.f .51. Potential Sunnly e.f.m. Source Picker Hcuce Breaker Card Room Carding and Spinning Room 22,600 12,000 58,000 Twisting Department 33,600 {17,800 Existing Carrier Unit, modified Existing Carrier Unit, 36,000 r modified c26,400 Overflew from Twisting Department f33,600 Required portion from, avail able supply of 60,000 from main Carrier system It appears from the tabulation above that there are available means for supplying all requirements except that for the Picker House. It is believed that this may be cared for by air cleaning units to peimit recircu lation from some of the systems handling small amounts of dust. (See following section.) .004695 INDUSTRIAL. HVGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the U. S. Asbestos Div. of Raybestos-Jianhattan, Inc., ilanheim, Pa., Uarch 14,15,16,17, 1944. 14. -**58 AIR FILTRATION An effective dust collector which v/ill produce clean air i.e., one with a dust content of less than 1/4 million particles per cubic foot, would have valuable applications. It could serve to reduce the unbalance between air exhaust and air supply by drav/ing air from the dust house for recircula tion and also would permit direct recirculation from some of the exhaust sys tems that handle relatively small amounts of dust such as those for the L-frames and for the winders and twisters; We have in mind particularly the indicated deficit of about 25,000 c.f.ra. for the Picicer House. Recirculation of air from dust collector systems where the dust is inherently hazardous to health is generally frowned on and we are among those who usually discourage the practice. This i3 because of the difficulty of maintaining such equipment so as to assure the purity of the air returned. However, it is not often that there are economic incentives as great as in the present case. We believe an exception is warranted here and recommend certain preliminary experimentation which will lead to an adequate system that wiltLvercoma the objections usually encountered. I* is recoesnended for this purpose that a small unit be constructed for connection to the dust house or to a system serving Foster winders or L-fraaes so that tests including dust counts in the effluent air can be con ducted. The unit illustrated has bogs 6** in diameter and about 7s* long providing a cloth area of approximately 10 eq. ft. per tube. This unit can CQ4S9Q INDUSTRIAL. HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the U. S. Asbestos Div. of Rayb03tos~Manhattan, Inc., Manheim, Pa., March, 1-4,15,16,17, 1944. 15 be made v/ith as many tubes as desired. Y/e show six for a total of 60 sq. ft., and whoso capacity nay be anywhere from 100 c.f.n. to 600 c.f.m. depending upon the application. It is contemplated that the cloth will bo plugged with some inert dust preliminary to actual use, for example limestone dust, until its preliminary resistance is 0.1 to 0.8 inches at a filtration velocity of 1 f.p.m. This will probably require about 1/2 ounce of dust per sq. ft. of cloth area. The design is illustrative only. It may bo advisable to increase the size to fit an available blower. Further, to avoid the inconvenience of finding a source of supply for the inn'll quantities of filter cloth required it is suggested that bags be ordered from a manufacturer of such collectors, in which case the metal collars and other pertinent dimensions of the housing would be changed to accommodate the bags. Either of the following is suggested: 0. F. Berg Company East Pedham Street Boston, Mass. Parsons Engineering Company 3589 East 82nd Street Cleveland, Ohio. INDUSTRIAL HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation survey of the ff. S. Asbestos Div. of Raybestos-Hanhattan, Inc., Llsnheim, Pa., March 14,15,16,17, 1944. 16, SUMMARY OP RECOJ&OTDATIONS Picker House 1. Modify exhaust for pan crusher hoods, providing 1250 c.f.m. per hood and interconnected hinged doors. 2. Repair cast iron cover on Saco-Lowell vertical opener where dust leakage occurs, J 3. Consider the installation of a batching bed enclosure, with movable side and air exhaust in volume to create face velocity of 100 f.p.m. j (See page 4 and figure 1.) Carding Machines 4. Install curved trays under the feed rolls of the finisher cards requiring them. (See page 5.) 5. Construct experimental removable cover for one or two finish cards for dust from upper wiper roll and rub apron. (See page 6.) 6. Construct experimental slot-hood for lower wiper roll and rub apron* Provide connection to exhaust system at a convenient location for testing. and another for attachment to one or two selected machines. (See pagefc ft and 7 and figure 2.) Air Filtration 7* Construct a modal filtor dust cclleotor for effioioney tests with arrangements for connection to dust house for ono test and to spinning and tvdsting exhaust system for another. (See page 14 and figure 4.) It would be advisable to complete most of the above prior to our next visit, especially Noe. 1, 4, 5, 6. CC4G90 INDUSTRIAL. HYGIENE FOUNDATION OF AMERICA. INC. Industrial ventilation surrey of the tf. S. Asbestos Div. of Raybestos-Manhattan, Inc., Wunhaim, Pa., March 14,15,16,17, 1944. 17 ELECTRON LECCROSCOPE BCAlgi-IATIOlT OF DUST It was felt that an examination of the air-borne dust by the electron microscope would throw some additional light on the fundamental problem of asbestosis even though we draw no definite conclusions therefrom* One scliool of thought maintains that the pulmonary condition results from a mechanical action of asbestos fibers on lung tissue, yet the dust seen in counting is almost all non-fibrous. Through the courtesy of the research laboratories of the Aluminum Company of America, which is a member of Industrial Hygiene Foundation, electron microphotographs of air-borna duet have been obtained and are appended hereto. The dust was collected with the electric preoipitator in the carding loom. Two questions were propounded by us to the laboratory, as follows: 1. Are the cubical (non-fibrous) particles that are seen in the light microscope used for counting actually composed of unbroken bundles of fiber as in the parent rock? (Particles of this shape comprise over 95$ of those seen and counted.) ;>vSir Is there a large quantity of fibers whose length is several microns but which are invisible by the light field set-up because their diameter is below the limit of resolution? The report included the followings 004G99 INDUSTRIAL HYGIENE FOUNDATION OF AM ERICA. INC. Industrial ventilation survey of tbs U. S. Asbestos Div. of Raybestos-Uanhattan, lac*, tfaahoim, Pa., March 14,15,16,17, 1944. 18 "Tbs dust was found to contain many fibrous particles as we11 as aon-fibrous particles as shown in Pig. 1# At the magnification used for this micrograph (5000X), however, the non-fibrous particles may appear to predominate. This is not the case and no doubt results from the small size of the fibers as examination at high magnification shows that much of the material is present as small fibers as shown in Fig. 2. The fibers were found to range in length from a fraction of a micron up to a few microns with an average length of about 1 micron. The thickness of the small fibers ranged from 0.01 micron to 0.05 micron (100-500 Angstrom units) with the average closer to the lower limit. "The nature of the non-fibrous particles probably is as suspected that is, they consist of bundles of fibers which have not been broken apart. This is evident from a few of the particles in Fig, 1 and particularly from the particle in Fig. 3* Several fibers protruding from the end of the large bundle are shown in the latter micrograph." *r OG47uO ^ v >:*/ * ^ Vf`:' ^:,\:fV'-^'^-.- ^'^--; -; *0' ',*'> V'-^Vvi'V .'*'. :. f ; ' 4j ^", `0 . v\< <k* >'"'' '*>'** 'r:- fejr';? f V%' *' '*' '* .* \ *v*.*^_ 0 *** / * . y\fl , * \ ' W 1 * h* * ' -;. .>..' * _.. v *>.- X;> < : ,ow **> .-\.,/* ' f^ .., ^ <. . <f vm a. - v '> *;; ..t ?>:! v AW * .. fc ' ; ;*'*: ,, ' * ; * . , V . _ . ., < !. * V^ ^\ v\ J,. \ v;^ah '' /^"Y : - /, v.-..-\ -. * *' '-1 * - " ` x- * ' ?._**>! / ; ,V I y. . tv v */V% ;V h /`V' -4 * . v... ,,. ^v:"A',v,,v .; , '. l*. >u_-- ...> ^ ~ t# * ^ 1 I i .jl-. 1- :.*P /<' *. * W.-V 1 J.` I'.v 1 .LOV. the '.rtr> : .-v,r.,-, ; s> - V 004701 T* X ':<K 004702 \% G047Q3