Document dDNZ3Ykzoa7Yxq0BvvOrDKo39

BBfQKT AHD EECOaMEBBASIOItS KELATI*!G TO THE CFEPATIGHS h i t :e FLAST OF Tifflt AMERICAH CfmQXBJJS PEOCOCTS COHPAMY, LCBAIH , OHIO r- hake Out Ideally tala operation Is carried out mechanically in a totally enclosed ventilated hood la which case 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 be liberated during ih shake-out depend to a considerable extent on `he amount present, tha next best arrangement is that of a combination operation, in which the bulk of the sand !s removed mechanically In a totally enclosed ventilated hood and the remainder removed by hand in a hoed which develops positive suction at t he 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 the operator and toward the emptied flask. This requires strong down draft through the grating and a lateral alr-gstboring hood on too 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 i also necessary to have very strong downdraft through the grates and very strong updraft through an overhanging canopy hood suspended over the bafce-out area. This airangoaont require hug quantities of air and is none too good at best. In our opinion, the operational requirement at this plant do i not require this compromise We recommend as 'first choice the totally enclosed station followed by the laterally ventilated hand shake-out. station as per sketch A, or, as second choice, the laferall ventilated station alone with access 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 300 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 without making sure such addltioB lias net changed the efficiency of ventilation of the original machines. A velometer should be used to check the air flow at and near the intake, and such checks should be repeated on a regular schedule to insure continued efficient operation. 0021660 5 and Blast and Wheel Abrades* operations \ hs sand blast room should be totally enclosed and .eatHated and, of course, 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. Inhaust 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 Isas shown what 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 aorader. Air sampling tests will be required to establish the amount of air movement necessary and to check on the tightness of the machine* The vent, of course, b*s discharged to : ue outside * barfo ho:e Knock-out Down and lateral draft ventilation concentrated near- the knock-out level should be adequate for this operation* The hood design can be similar to the shake-out hood with the grata at floor level and the hood structure elevated* rom-inf!. I- rations consideration should bo given to a lateral draft slotted and overhead hood at the ''permanent ** pouring stations The overhead general ventilation should be retained, bus it is a reasonable expec tation ihat the lateral and overhead hoods will perform more efficiently with the general overhead ventilation reduced* Pouring of the larger easting should either bo done under a hood of efficient capacity to prevent general diffusion of ! fumes, or a suitable portable flexible tube exhauster should bo KE 0021661 provided to collect the faa at i-hts source (Cooper typo exhausters would probably be suitable} The us of a ventilated pouring ladle (to he described below) might make it unnecessary to consider these uggestions $ in which case the general exhaust fane would be retained at present, or at reduced capacity * Portable Hood for Pouring, Ladle It has been recognised for sea time that sea method is needed to reduce or control the fuses from the molten material la -he ladle from th time the ladle is charged until all of the material is poured from iv. Probably the most concentrated exposure to workmen occurs during - the period during which the ladle la being transferred from ihQ i'umace room to the pouring station. During this time the fuse in also being diffused throughout the plant:. The use of the portable hood reported in Bulletin Ho* 7* February 1947 of the Kentucky Department of Health recognises the h&saxd during the pouring, operat.ion* but it la not clear ocw the iunsss are carried away during transportation unless the pouring station .is adjacent to r.e furnaces. Sketch C illustrates a ladle? carrier with ladle ventilation and fuse filter. In principle It fulfills the requirements , Put it obviously will, require development, under actual operating conditions.. Pl`.:h '.'te 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 sore acceptable Experimentalion. will be necessary to determine the best; type of filter* and this may bo a problem because cf `.he high temperature to which such equipment will probably be exposed. We offer this idea for consideration for development and * rial It is quite possible that this could be dene in cooperation with other industrial organisations that are presented with this, as yet* unsolved problem. ' *?* ? n loar that equipment which would meet ^ 0021662 z> bis situation properly would reduce materially the specific and general lead exposure and vould diminish flatly the general ventila"ten otherwise required. Peno' aI lent Hat ion and Heat lap; In general, various operations which are not referred to specifically do not require separate ventilation but. should have so2*c loan general ecssfort ventilation. It must be remembered that, the molding sand cor tains particulate lead, and that excessive dust In association with the handling of the sana can produce an elevated lead concentration in the atmosphere. '-.Ye overall air flow must be directed from clean areas to these of potentially high concentration and thence to the outside. Hines whatever air is removed must be replaced with clean tempered air (in the winter) the inlet and outlet olumos must be reasonably balanced in order to attain the desired air flew as above described. Per economic reasons short circuits which do not roxacie con- atsinants must bo avoided. The overall problem of ventilation of this plant is complicated by the low roof construc tion which, interferes greatly with the rapid dissipation of fumes. :: he heater exhaust must bo 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 trie heater outlets could he high above floor levels. Tii installation of the proposed heaters should, however, make it possible to maintain more comfortable conditions and at the came time materially reduce the overall and local lead concentration during :he winter months, fine a large amount of heat la liberated in the. i ovnace room, a minimum amount of tempered air will be required for this rocI banco the cold air intake .in the design. The advisability of employing a velomotor to measure air flow and to check on the airflow 0021663 at different seasons of tm year cannot be overemphasised* All openings not normally Intended as part of the ventilating system should be studied to determine if they are aiding or hindering, the 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 tb furnace room, which generally churn 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 offeetiv in carrying away contaminants than a faster moving gusty *urtulsnt mass or air. The total existing fan capacity is many times the projected tempered air inlet capacity. If hooding as suggested accomplishes the ends intended, li is possible that much or the general ventilation can be reduced, thereby promoting a more comfortable working envir-oninont during the winter period. "'`bIIl Operations and *&>usekeeriag ,?1h foundry is somewhat overcrowded, and it. is realized that- under such conditions meticulous housekeeping is difficult i:e>ertholess, becau 1 Ij&i* stirring up of dust my be an important factor In the hazard, very reasonable effort.should be mad to keep the plant clean and, by the use of water and sweeping compound, to reduce dust to a minisua. R&f.ter dust should be removed periodically, not only to prevent its dissemination but to promote general interest in good housekeeping. Oeneral HealtIt The recommendations made cy footer &onoo ducod May i.:, should be reviewed and to the extent that they arc not being followed they should b put into effect. Ingestion of lead by eating a sandwich K? 0021664 7 cased on tne .Instaliat;Ion of elaborate ventilation equipment* Moreover .bio is an wholly unnecessary type of tosard vfcCoh can be eltoinated by odueational and disciplinary' means it tout costly equipment Cnnetal ;e rsccssmendatlojfte contained herein, which are in substantial agreement with those made by the Otoo State 'ii&alth Department indicate the nature of the problem and the general means cf correcting the existing situation. The axtesa cf gathering the contaminant at its ;;ouv!t? and supplying gfca&rai ventilation to carry away apt Xlag* *>tould, :.r properly Implicated * reduce i.'m lead l@ve.\ ihrougt.otit. to accept a* ..!<= levels. -Yto details of design and construction arc not vithin tto scope of this report , Oovover* it ia hoped that sufficient advice Ida been given to enable operating personnel and a competent contractor o install the equipaent required* toy furttor assistance that can bo c: ovided iy chocking prints and e peoif i eat ions as `toy are developed, or by ortor means vithin the province cf tola Laboratory will be available on request # irem the ferine l^toraiory in '.to Department of Preventive Medlain and Industrial Health in tt College of* Medicine, University of Cincinnati, Cincinnati, Ohio Report and drawings by* bester is* Viobs-rts?, Consulting Engineer aojs py, Xy{jX r-irsetor KZ 0021665