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MineralsEngineeringVolume14,Issue11,November2001,Pages1459–1468英文原文COMMINUTIONINANON-CYLINDRICALROLLCRUSHER*P.VELLETRI~andD.M.WEEDON~~[Dept.ofMechanical&MaterialsEngineering,UniversityofWesternAustralia,35StirlingHwv,Crawley6009,Australia.E-mailpiero@mech.uwa.edu.au§FacultyofEngineeringandPhysicalSystems,CentralQueenslandUniversity,POBox1!:;19,Gladstone,Qld.4680,Australia(Received3May2001;accepted4September2001)ABSTRACTLowreductionratiosandhighwearratesarethetwocharacteristicsmostcommonlyassociatedwithconventionalrollcrushers.Becauseofthis,rollcrushersarenotoftenconsideredforuseinmineralprocessingcircuits,andmanyoftheiradvantagesarebeinglargelyoverlooked.Thispaperdescribesanovelrollcrusherthathasbeendevelopedinordertoaddresstheseissues.ReferredtoastheNCRC(Non-CylindricalRollCrusher),thenewcrusherincorporatestworollscomprisedofanalternatingarrangementofplaneandconvexorconcavesurfaces.Theseuniquerollprofilesimprovetheangleofnip,enablingtheNCRCtoachievehigherreductionratiosthanconventionalrollcrushers.Testswithamodelprototypehaveindicatedthat,evenforveryhardores,reductionratiosexceeding10:1canbeattained.Inaddition,sincethecomminutionprocessintheNCRCcombinestheactionsofrollandjawcrushersthereisapossibilitythatthenewprofilesmayleadtoreducedrollwearrates.Keywords:Comminution;crushingINTRODUCTIONConventionalrollcrusherssufferfromseveraldisadvantagesthathavelcdtotheirlackofpopularityinmineralprocessingapplications.Inparticular,theirlowreductionratios(typicallylimitedtoabout3:1)andhighwearratesmakethemunattractivewhencomparedtoothertypesofcomminutionequipment,suchasconecrushers.Thereare,however,somecharacteristicsofrollcrushersthatareverydesirablefromamineralprocessingpointofview.Therelativelyconstantoperatinggapinarollcrushergivesgoodcontroloverproductsize.Theuseofspring-loadedrollsmakethesemachinestoleranttouncrushablematerial(suchastrampmetal).Inaddition,rollcrushersworkbydrawingmaterialintothecompressionregionbetweentherollsanddonotrelyongravitationalfeeci~likeconeandjawcrushers.Thisgeneratesacontinuouscrushingcycle,whichyieldshighthroughputratesandalsomakesthecrushercapableofprocessingwetandstickyore.TheNCRCisanovelrollcrusherthathasbeendcvelopedattheUniversityofWesternAustraliainordcrtoaddresssomeoftheproblemsassociatedwithconventionalrollcrushers.Thenewcrusherincorporatestworollscomprisedofanalternatingarrangementofplaneandconvexorconcave:Icanbeattained(VellelriandWeedon,2000).Theseinitialfindingswereobtainedforsingleparticlefeed.wherethereisnosignificantinteractionbetweenparticlesduringcomminution.Thecurrentworkextendstheexistingresultsbvexamininginulti-particlecomminutionintheNCRC.Italsolooksatvariousothcrfactorsthatinfluencctheperli~rmanceoftheNCRCandexplorestheeffectivenessofusingtheNCRCfortheprocessingofmillscats.PRINCIPLEOFOPERATIONTheangleofnipisoneofthemainlectorseffcctingtheperformanceofarollcrusher.Smallernipanglesarebeneficialsincetheyincreasetl~elikelihoodofparlictesbcinggrabbedandcrushedbylherolls.Foragivenfeedsizeandrollgap,thenipangleinaconventionalrtHlcrusherislimitedbythesizeofthcrolls.TheNCRCattemptstoovercomethislimitationthroughtheuseofprofiledrolls,whichimprovetheangleofnipatvariouspointsduringonecycle(orrevolution)oftherolls.Inadditiontothenipangle,anumberofotherfactorsincludingvariationmrollgapandmodeofcommmutionwereconsideredwhenselectingIllerollprofiles.ThefinalshapesoftheNCRCrollsareshowninFigureI.Oneoftherollsconsists{sIanalternatingarrangementofplaneandconvexsurfaces,whiletheotherisformedfromanalternatingarrangementofphmeandconcavesurlaccs.TheshapeoftherollsontheNCRCresultinseveraluniquecharacteristics.Tilemostimportantisthat,lk)ragivenparticlesizeandrollgap,thenipanglegeneratedmtheNCRCwillnotremainconstantastherolls°.Thus,thecylindricalrollcrusherwouldnevernipthisparticle,sincetheactualnipangleremainsconstantatapproximately52°.ThenipanglegeneratedbytheNCRC,however,tidlsbelow25°onceastherollsrotateby(~0degrees.Thismeansthatthenon-cylindricalrollshaveapossibilityofnippingtheparticlc6timesduringonerollrewHution.EXPERIMENTALPROCEDUREThelaboratoryscaleprototypeoftheNCRC(Figure3)consistsoftworollunits,eachcomprisingamotor,gearboxandprofile