Document g2483mGMr78EO8KMO7E8OBgdq

REPORT AxW RECOSMRHBS:XQ3S8 RELATING TO THE OPERATION IH TIE PLAST OF THE AMERXCAH CF130IBJS PRODUCTS COMPANY, LCHAX3, OHIO Inalre Out Ideally tills operation Is carried out isecliaaically in a :orally enclosed ventilated hood in vhich cas the operator has no exposure This ideal situation Is rarely entirely practical fro an operating standpoint, since# Generally# residual sand must be knocked off from the castings by band. However, since the amount of dust which will l> liberated during the shake-out dependa to a considerable extent on *he amount present , ;is next best arrangement is tiiat of a combination operation, in which th bulk of the sand !s removed mechanically in a totally enclosed ventilated hood and :h remainder removed by hand. in a lined which develops positive suction at the face of the operator* It is possible safely to carry out the entire operation by hand providing sufficient lateral air movement can be maintained away from th operator and toward the emptied flask. This requires strong down draft through the grating and a lateral air-- gatboring hood on toe far side and over the shake out* as per- sketch A. If it is necessary to lave access to the flasks item two sides, it is also necessary to have very strong downdraft through the grates and very strong updraft through an overhanging canopy hood suspended over the shake-out area. This arrangement require huge quantities of air and is none too good at best. In our opinion, the operational requirements at this plant do i not require this compromise We recommend as IfIrat choice the totally enclosed station followed by th laterally ventilated hand shake-out. station as per sketch A, or, as second choice, the labor-all ventilated station alone with acceso fro one side only. Grinding, Chipping, saving operations All grinding, chipping and saving operations should he vented in such a manner as to gather the material as soon as possible at the point of origin. In general, this requires air velocities of not less than 30 0 feet per minute at the inlet over a sufficient area to insure efficient collection of the particles. The hooding should he so located that the particles given off are dravn directly into the opening. An horizontal arrangement of the exhaust at the side on to the rear is generally most effective. Reference is made to Industrial Health Engineering (Brandt) for details of design applicable to such operations. Since ventilation requirements for this type of equipment depends on the nature of the material being handled, and since there is generally some sacrifice of flexibility of operation in order to provide adequate ventilation vhen lead or other potentially toxic materials are being handled, manufacturers in general do not provide adequate protective equipment for handling such materials. It Is then necessary to "custom design" the equip ment and by trial and error arrive at the optimum design for each machine and operation. It is vise, therefore, in estimating the ventilation requirements to overdesign in order to have sufficient capacity for the trial and error experimentation. Ducting should be designed for a particular machine or group of machines to permit proper ventilation vith all machines running. Once balanced other machines should not be tied in to the common duct vithout making sure such addltioil lias not changed the efficiency of ventilation of the original machines. A velometer should be used to check the air flov at and near the intake, and such checks should be repeated on a regular schedule to insure continued efficient operation. 5 rand Blast and Where! Abrades* operations lie sand blast room should be totally enclosed and .eatHated and, of coarse, protective equipment supplied to the operator. Discharge should bo collected in a system which is designed (and tested) so as not to leak Into the interior of the .ruilding* Ihrbauet after collection should be discharged to the outside in such manner that it cannot be returned Into the building. Wheel abraders generally are not absolutely tight and experience lias shown that more than just normal ventilation is required. We recommend, -horefore, that this equipment be located near a positive exhaust fan of sufficient capacity to keep positive air movement: from a clean area to the aoxaders Air sampling tests will be required to establish the amount of air movement necessary and to check on the tightness of the machine* Tho vent, of course, Krai.--- be discharged to :ue outside * :..-arr;o bo; e Knock'"out Down and lateral draft ventilation concentrated near the knock-out level should he adequate for this operation* The hood design can be similar to the shake-out hood with the grate at floor level and the hood structure elevated. T-oarlng. I rations Consideration should bo given to a lateral draft slotted and overhead hood at the R e m a n e n t " p o k i n g stations. The overhead general ventilation should be retained, but it Is a reasonable expec tation m a t the lateral and overhead hoods will perform more efficiently with the general overhead ventilation reduced* Pouring of the larger casting should either bo done under a hood of sufficient capacity to prevent general diffusion of : fumes, or a suitable portable flexible tube exhauster should be provided to collect the fume at Iha s o 'utc c (Cooper typo exhausters would probably be cultable.} The us of a ventilated pouring ladle (to he described below) might make it unnecessary to consider these suggestion $ in which case the general exhaust fans would be retained at present, or at reduced capacity. . Portable ?iood for Pouring Ladle . It ras been recognised for acoet line that some method is needed to reduce or control the fuses fro the molten material la -he ladle from itm time the ladle la charged until all of the material 1 poured from it. rrcbably tin most concentrated exposure to workmen occurs during tbs period during which the ladle la being transferred from the furnace rocs to the pouring station* Luring this time the fumo in also being diffused throughout the plant. The use of the portable hood reported in Bulletin Ho* 7* February 1947 of the fen::uck.;/ Lepar t , meat of J1?i-V&-Xth.re raises the hanaxd during the pour ***.< j . < *r > operar ion* but f A- to not :lear hoy the fuses are carried away duri f** *ranspor tation uniess wiring station .is adjacent to he furnacee fc.LwaOi*eh 0 11 Ins lf*^* '2 W 4Uos ; ladle carrier with ladle ventilation and fume filter . In principle 1 fulfills the requirements, but it covi cuciy will require do 1Shv`43 vo*pet; : under actual operating conditions.. Pith -hi arrangement a trolly will be necessary to run the blower. he sketch shows a hydraulic lift system* Probably a mechanical worm gear control would be more acceptable theperiaentation will be necessary to de*temine the best type of filter# and this may be a problem because of the ligi* temperature to which such equipment will probably be exposed. Vie offer this idea for consideration for development and *rial It is quite possible that this could be done in cooperation with other industrial organisations that are presented with tifi, as -et* unsolved problem. jt cieilI. that equipment which would meet bis situation properly would reduce materially the specific and general lead exposure and would diminish greatly the general ventilafien otherwise required. Oener aI tentH a t ion -and Heat:lap; la general , various operations vnich are not referred to specifically do not require separate ventilation hut. should have 20 2*e than general comfort ventilation. It must be remembered that the molding sand cortalas particulate lead, and that excessive dust !.n association with the handling of the cana can produce an elevated load, concentration in the atmosphere. ":ve overall air flow must be directed from clean areas to these of potentially high concentration and thence to the outeide. Pines whatever air is removed must be replaced with clean tempered air (in the winter) the inlet and outlet olumca must be reasonably balanced in order to attain the desired air flow as above described. for economic reasons short circuits which dc not resje?* e contaminants must be avoided. the overall problem of ventilation of this plant is complicated by the low roof construe'ion which, interferes greatly with the rapid dissipation of fumes. ::be heater exhaust must be more carefully considered in relation to the workmen and to general work areas because of the possibility of excess local hot air drafts near the exhaust and cold air nearby. This would not be true if the heater outlets could be high above floor levels. The installation of the proposed heaters should, however, make it possible to maintain more comfortable conditions and at r.he same-time materially reduce the overall and local lead concentration during :he winter months * f-ince a largo amount of heat la liberated in the. a vii'-aace roost, a minimum amount of tempered air will bo required for this rocl banco the cold air intake in the design. The advisability of employing a velometer to measure air flow and to check on the airflow at different seasons of tns ear cannot be overemphasised* All openings not normally Intended as part of tm ventilating system should be studied to determine if they are aiding or hindering, tbs ventilation pattern* If they hinder, they must be kept, closed and made difficult of opening. Cooling blowers of the type now la use on the floor in the iurnaee room, which generally chara up the air, should not be used unless testa show that their use in any particular situation doe not interfere with the general desired ventilation pattern. A slowly and steadily moving mass of air is often more effective in carrying away contaminants than a faster moving gusty *urtuleat mass or air. The total existing fan capacity la many times the projected tempered air inlet capacity. If hooding as suggested accomplishes the ends intended, it is possible that much or the general ventilation can be reduced, thereby promoting a more comfortable working environment during the winter period. .Dust;;- foerat ions and itoasekeeriag ,?1h foundry is &emevMt overcrowded, and it. is realized ib&t under such conditions meticulous housekeeping is difficult ireverthtle&s, because the stirring up of dust m y be an important factor In the baxard,every reasonable effort.should be mad to keep the plant clean and, by the use of water and sweeping compound, to reduce dust to a minimum. Raf ter dust should be removed periodically, not only to prevent its dissemination but to promote general interest in good housekeeping. Cenex-al Health , The recommeadat ions made by root or Kobos dated May 19, 19^5 should be reviewed and to the extent that they are not being followed they should be put into effect. Ingestion of load by eating a sandwich 7 based on tue installation of elaborato ventilation equipment. sforeover tbi& ia an wholly unnecessary type of liasard which can be eliminated by educational and disciplinary' means without costly equipisent fonerai :e rcccssacndatlorn contained herein# which are in substantial agreement tilth tiro made by the Ohio State Jiealia Itepartment indicate the nature of the p^ohi.r and the general means of correcting the existing situation. The axiom cf g&tiierinp; the contaminant at its ou*,et* d supplying general ventilation to carry sway spillage should, :.r properly implemented# reduce the lead level tbrougt.oot. to accosta ,.-ie l e v . Y;-*? details of design and construction arc not within t}iG scope of this report# ilovover* it is hoped that sufficient advice I'*3 been given to enable operating personnel and a competent contractor o install the equipment required. Any further assistance that can bo provided i;; clicking prints and specifications as are developed, or by other means within the province cf 'this Laboratory will be available on request. I-row the lettering laboratory in vhs Department of Preventive H a l a l m and Industrial health in tii College of Medicine, Baiveririty of Cincinnati, Cincinnati, Ohio ' report and drawings hjt bester 5 ftobert*, Consulting engineer dune lb', l^iX E 1rsctor 0021665