Document BvDLB72kk22RbZ0OvmOmakmLJ

FILE NAME: General Electric (GE) DATE: 1933 Mar 29 DOC#: GE174 DOCUMENT DESCRIPTION: Unpublished Recommendations - Protection Against Dust Hazards in Air-Pressure Abrasive Blasting Under ihe fair use provisions of the copyrightTa^/jif tMJtfeed States (17 USC 107), this single copy was % ? efeit`S3:3 lie cnlv from material m Manuscripts and Archives, Yale University Library, P.O. Box 208240, 128 Wall Street, NewHaven CT b652C-8:UC " Uornplelasscepdermmitshseiocnolilsecgtriaonntsedo,fnaeniythienrstthitiusticoonpyornionrditvhieduwaol,rds on it may be: reproduced in any form; used by an unauthorized person: PROTECT-ION AGAINST DUST HAZARDS IN AIR-PRESSURE ABRASIVE BLASTING Recent stu d ies have in dicated various methods by which air-p re ssu re abrasive b la stin g can be c a rrie d on w ithout exposing workers to danger from in h a la tio n of harm ful d u s ts , th e c h ie f of which is s i l i c a . Some of th e se methods a re ap p lic a b le in c e r ta in p ro c e sse s, some in o th e rs ; and th e re may be a d d itio n a l pro cedures not here lis te d which w ill ensure sa fe ty . 1. Choice of A brasive. The use of m e ta llic ab rasiv es in stead of sand a blorwa s ipvreosp owrthieornes f e -a ssibo leloww itlhl act unt ododwanngtehre naemedoubnet aonf tsiciilpi caate din utnhdeerd us asttistfoa cvteoryr y woforrkoiunngdecdo npdeitliloent ss ., and S" gtereitl" awb rhaicshiv ehascomroeusghin etdwgoesf.ormsIn -n&"nsyh optr"o cwe shsicehs, c hoonws iesvtesr, sHuacrhd sa t es eu lb sptiatruttiicolne sc, ancanuogt hbt e inmaadne gwleisth oouf t csaastcirnigfsic eor oof theceornwoimsey ar nedta ienfefdic,iemnacyy . dalaummaigneummaacnhdinea lltooyo lsc aisftintgh se csaansdtinagbsraasirvee tog ivbees l aat ebre tmtearchfiinneids.h anFdorwcilteha naliunmg inum i t produces a given r e s u lt in a much s h o rte r p erio d of tim e. S urfaces are sa id to hold p aints or enamels b e tte r a fte r sand treatm ent (although c e rta in companies employ m etallic ab rasiv es w ith su ccess), and d isco lo red surfaces are more e ffe c tiv e ly cleaned by hand. Hydraulic b lastin g , applying a water stream a fte r the use of silic e o u s or n o n -siliceo u s a b ra siv e s, h as, in some in stan ce s, proven p r a c tic a l. Subsequent d ry in g may be n ece ssary to avoid r u s tin g . 2. S andblast B a rre ls . B lastin g medium sized and sm all castings in properly dinesitghneedwosrakrnodobmlaasit r bsaor r elolws acsan tobeavcoonidduacnteyd s esoriaosu sto hkaezeaprd thweithd uasnt yc otynpcee notfraatiborna s iv e . Such a b a r r e l c o n s is ts of a drum made of heavy sh e e t p la te , mounted as a ru le on trunnions and capable of r o ta tio n . The ro ta tio n serves to brin g th e o b jects btrleaastteindg udnudestr tehsecapsaesn dfbrolamst thsetrebama rsr e llo cina tteod thine rtohoembaairrr eul.n less Inth ethoapppraorcaetusss iosf com pletely enclosed. Each b arrel snould therefore be tig h tly constructed and kept under exhaust pressure by special v en tilatio n during the blastin g process hanodusainlsgo wwhihcihle etnhcelobseasr r ethle isb abrer einlg wehmilpetieind aofpteerra tbiolna satinndg w. hichAiscomprpolveitdeedo uwteirth a door fo r f illin g and emptying the b a rre l is advantageous. The housing space should also be provided w ith exhaust v en tilation. B arrels andhousing should be kept tig h t and in good rep air and the doors of b arrel and housing should f i t tig h t ly . It is im portant too, th at care should be exercised in the loading and un lcoomadeinfrgomprothceessfoutondaryvoaids gc leetatinn gandd ufsrte ein tforomth esanadi r .as p o sAs ilbl lsem. all c aInstilnogasd insghoculads t ings covered w ith a d h eren t foundry sand , th e e v o lu tio n of d u st may be reduced by th e use of c h a in -h o is t lo ad in g s k ip s . The in te rfe re n c e of w orkers w ith th e ma chinery (a s, fo r example, by tam pering w ith th e abrasiv e sep arato r mechanism) should be s t r i c t l y p ro h ib ite d . B a rre ls should not be s e t above the head of th e worker so th a t sand may r a in down on him . 3. Sand B last T ables. The ro ta tin g sand b la s t tab le can be used w ith c e r statriun c ktiionnds, coifr cwuolrakr wiinth shsaimpeilaanr d suocrcdeinssa.rily 6Thoesre 7tafbe elets oarremooref hineavdyiamm eettaelr. conT he> are o rd in arily set about 3 fe e t above the flo o r and ro ta te slowly a t a speed of perhaps 1 -1 /2 re v o lu tio n s p er m inute, The ta b le is d iv id e d in to halves by a s e r ie s of f le x i b le , s p l i t ru b b er c u r ta in s . One sid e of th e ap p aratu s is com plete ly enclosed (by housing and by these cu rtain s) and is provided with nozzles for Under the fair use provisions of the copyright law of the United States (17 USC 107), this single copy was produced for reference use only i ,, j from material m Manuscripts and Archives, Yale University Library, P.O, Box 208240, 128 Wall Street, New Haven CT 0( 52C-8240, (C jj Unless permission is granted, neither this copy nor the words on it may be: reproduced in any form; used by an unauthori; ed person; 1 or placed m the collections of any institution or individual. Under tne fair use provisions of the copyright law of the United States {17 USC 107), this single copy was produced lor reference use only . from material m Manuscripts and Archives, Yale University Library, P.O. Box 208240, 128 Wall Street, New Haven CT C652C-824C " '{ Unless permission is granted, neither this copy nor the words on it may be:_r<jgroduced in any form; used by an unauthorized person; di or placed in the collections of any institution or individual. d isch arg in g the a b ra siv e on to the work which lie s on the ro ta tin g ta b le below. A worker statio n ed a t the opposite side removes fin ish ed ob jects, turns over those which re q u ire tre a tm e n t on th e o th e r sid e and feed s in new m a te ria l. The c h ie f ceus srteanintisa l upinon thwehousese e offfictiheinsc yd evi tiscewihsoleth esu cpcroespserddepeseingdns. and Ihuepkceleopseodf sthidee s pofl i tth e apparatus should be provided w ith e ffic ie n t exhaust. Where larg e p arts a re dtrietiaotne sd , pdrou tset c itsio nli kies lyin atod eqesucaatpee. when th e c u rta in s a re l i f t e d and under such con p re ssu^r`e S(6a0n dpboluansdts Coarb imnoertes). thWehesraensdmb laallst ocbajebcintse ta, reo ftteon bec acllleedanethde w"ihthyghieignhic a ir cab in et w ill meet a ll h ealth needs. Such a cabinet is of s te e l pLate construc tio n , usually 5 fe e t wide, 3 feet deep and 7 feet in height. It is ordinarily provided w ith a s in g le p re ssu re n o z z le . The fro n t of th e c a b in e t is provided w ith two hand holes through which the w orker's hands and arms pass in order to m anipulate the o b jects tre a te d and w ith a window of heavy p la te g lass through which he may view th e p ro g re ss of th e work. The m a te ria l to be clean ed is placed in soipdeerattboer cthaebninteutrnthsroounghth ea ahbinrgaesdiv edoojer t abt ythmeeafnrso notf aor fosiodte troefa dthlee , c apbasisneest. h is The arms through the hand holes and exposes a ll surfaces of the object to the action ooff tthh ee bfilnaes td. u s t Tprhoeduced icna btihneept roiscpersosviodfedb lwa sitthinagn. exhaustsystem fo r th e removal handhTohlees eafnfidc ioenn ctyh eoeffftihc iies ndceyv ic eof otbhveioiunstleyr ndaepl eenxdhs auonst.th eWhtiegreh tnthe ses haonf ddhooolsrss foanrd the operator are toolarge, the apparatus w ill obviously fa il to give protection. Handholes should be sm all and provided w ith g au n tlets and a separate opening a t back or sid e should be provided for introducing the work. p o s s i5b .le Aunudteormcaetirctaalilny cFoedn dBitliaosntsin gto Reomomplso. y Fcloorsetdr e asatinndgb llaasrtg eroocmass titnhgrosugiht wishich pthlaecemd a toenriaa l s utoitabbe letr ecaotnevdeyoisr bcoynaveyloeda dbeyr, authtoemcaotnicvemyoarchcianrerriye.s i tThethroobujgehc tsthea re room where i t is exposed to the b la s t and d e liv e rs i t cleaned on the opposite sid e of th e b la s t chamber. The tig h t housing of th e rooms and th e ir in le t and o u tle t tunnels, the upkeep of the curtains guarding the ex it and entrance to these tunnels danidtiotnhse wd ehgicrhee deotferemxihnaeusstuvc ceenstsil.a tio n m ain tain ed w ith in th e chamber a re th e con have Fpororvetrde ahtiignngly sms aatlils fcaacsttoinr yg.s , com p letely autom atic machines a re a v a ila b le which 6 Use of P o sitiv e P ressure H elm ets. Where none of the foregoing measures can be used , th a t i s , wher"- any a b ra siv e ' must be used in the open in a sa n d b la st proroomp eorlcycudpeiesdignbejrd thaned wooprekreart,edadpeqousaittiev ep-rporteescstiuorne chaenlmbeet. assureTdhebyheltmh eet umseusotf, haow ever, have glass and not screen eye sh ield s alone and must be provided w ith a clean fre s h a ir supply of 6 cubic fe e t per m inute. The co n d itio n of helm ets must be su b ject to reg u lar in spection to m aintain high e ffic ie n c y . The worker should continue to wear his helmet while in the sand blast room even a fte r the b la st is ttuhren efdin eo fdf ussitn. c e even th e b e s t system of v e n tila tio n w ill tak e some tim e to remove ' th a t wI torskheorsulda t bae dnjaocteedn t thoapte raa tlilo nsasnds hballal snt ortoobmes esnhdoaunlgderbede . kept d u s t- tig h t so Under the fair use provisions of the copyright law of the United States (17 USC 107), this single copy was produced for reUrence use only from material m Manuscripts and Archives, Yale University Library, P.O. Box 208240, 128 Wall Street, New Haven CT C1,520-8240. Unless permission is granted, neither this copy nor the words on it may be: reproduced in any form; used by an unauthor: .ed person, or placed in the collections of any institution or individual. Under the fair use provisions of the copyright law of the United States (17 USC 107), this single copy was produced for re erence use only from material in Manuscripts and Archives, Yale University Library, P.O. Box 208240, 128 Wall Street, New Haven CT 16520-8240 " Unless permission is granted, neither this copy nor the words on it may be: reproduced in any form; used by an unauthorized person, or placed m the collections of any institution or individual. -3- t on can e aossu red only throuWghhat cevoenrstsapn et cciaarle daenvdicessu pme rayv isbieo ne.mployTedhe, fporoll-o w ing elements m factory housekeeping deserve special emphasis: workroao.m. A ccum ulations of a b ra siv e should be removed each n ig h t from the b. Floors, tables, etc., should be thoroughly cleaned and swept each evening after the regular working staff has left and with proper protection of the cleaner by an efficient mask or respirator. Unless vacuum methods of clean ing are employed the dust should be thoroughly wet down before sweeping. c. Oiling of floors with ordinary fuel oil (one gallon to 100 square feet) has been found useful in certain foundry cleaning rooms. d. Care in loading and unloading castings is essential in order to avoid unnecessary dust. e. Dust co llectin g screens should be kept thoroughly clean. f . I t should be th r du ty of some one in d iv id u a l in each fa c to ry to make mre goutlhaer r preersiop de iccts .in sp e c tio n s of a l l ap p aratu s to ensure tig h tn e s s and good upkeep ana reg.g u laInr pinatretrivc ua llsa r byexshoamuests va teins ftialcattoiorny ampepanasr*a tu s should be te s te d a t fre q u e n t Under the fair use provisions of the copyright law of the United States (17 USC 107), this single copy was produced for reierence use only from material in Manuscripts and Archives, Yale University Library, P.O Box 208240, 128 Wall Street, New Haven CT C652C-8240. Unless permission is granted, neither this copy nor the words on it may be: reproduced in any form; used by an unauthorized person; or placed in the collections of any institution or individual