新型除尘采煤机除尘系统的研制

ACARPProjectC14036DevelopmentofaNewShearerScrubberSystemforDustControlBrianPlushEnviroConTingXRenandRaoBalusuExplorationandMiningCSIROMickBurgessBroadmeadowCollieryIntroduction•Dustexposureofoperatorsonlongwallfacesremainsachallengingtaskforminemanagements.•DustcontroltechniqueshavebeendevelopedintheUSA,UKandotherwesterncountrieswheretheirapplicationsaremoreapplicabletolowtomediumcoalseamheightsupto3.0m.•Dustcontrolinthickcoalseamsappearstobemoreproblematic,particularlyduetothedifferencesonfaceairflowpatternsandpotentiallyhigherdustgenerationandpick-upinthickseams.Introduction•WiththesupportofACARP,theCSIROhasbeeninvolvedinthestudiesofventilationandrespirabledustflowpatternsaroundthelongwallshearerandtheuseofvariousengineeringdustcontrolsthroughtheapplicationofCFDmodellingtechniques.•Duringthesesimulationstudies,thelongwallshearerscrubbersystemhasshowntobecapableofcapturingandsignificantlymodifyingtheairflowpatternsaroundthemaingatecuttingdrumandreducedustroll-uptowardsthewalkwayarea.Introduction•Theobjectiveofthisprojectwasthereforetodevelopanddemonstrateaninnovativeshearerscrubbersystemtoreduceoperatorsdustexposurelevelsonlongwallfaces.•ThedesignofthenewscrubbersystemhasincorporatedtheCFDmodellingfindings,includingthedesiredscrubbercapacity,theinletlocationsandtheairflowdischargedirectionfromtheelutriator.•Theproposedfieldtrialattheselectedminesitesdidnotmaterialiseasplannedduetositeaccessandcontractualissues.Introduction•ItwaswiththesupportofBMA’sBroadmeadowMineandtheirmanagementteamthattheproposedfieldtrialswerefinallyconducted.•Afterafewfailuresduringthetrials,amodulardesignedscrubberunitwassuccessfullyinstalledtotheMGrangingarmofthelongwallshearer.•Thisallowedtheevaluationofthescrubber.•CFDmodelshavebeendevelopedtoinvestigateairandrespirabledustflowpatternsaroundthelongwallshearer.•TheseCFDmodelswerevalidatedandthenusedfordetailedparametricstudiesandtoinvestigatetheeffectivenessofvariousdustcontrolsoptions.•Figures1and2showthe3Dmodelofthelongwallandthe3Dmodeloftheshearer.CFDModellingFigure1TheCFDlongwallmodelCFDModellingFigure2TheCFDlongwallmodelCFDModellingCFDModelling•Figure3showstheCFDmodellayoutwiththedustscrubberattachedtothelongwallshearer.DustscrubberFigure3.CFDModelling•Figure4(a)&(b)showsthemodellingresultsforthedustscrubberwithinletsfacingtheshearerdrumandventilationdirection.Figure4(a)ScrubberinletfacingtheventilationdirectionFigure4(b)ScrubberinletfacingtheshearerdrumCFDModelling•Modellingstudiesshowedthatitisimportanttocorrectlypositionthescrubberoutletlocationanddischargedirectiontoimprovetheoveralldiversionofescapeddustparticlesawayfromthefacewalkway.•Figure5showstheCFDmodellingresultsofdustparticlecaptureandflowpatternsbytiltingthescrubberdischargeat10˚(degree)towardstheface.10˚Figure5.Dustparticlecaptureandflowpatterns–scrubberdischargetiltedtowardsthefaceShearerScrubberDesign•Thecompletionofthisprojectrequiredthedesignandmanufactureof3individualunitsbeforethefinaldesignwassuccessfullyfittedandtrialledatBHPBilliton’sBroadmeadowCollieryintheBowenBasinNorthQueensland.•Priortothefinalscrubberdesignseveralmajorminingoperationalissueshadtobeconsidered.Themostpressingproblemwastodesignasystemthatwouldactuallystayontheshearer.OurFailuresOurFailuresOurFailuresOurFailuresShearerScrubberDesign•Thescrubberisamodulardesignedsystemconsistingofanintakehooddirectedintotheintakeventilation,ahydraulicdrivenfansuckingtheairintoanimpactfiltrationsystemandadischargeductforcingthecleanairundertheshearerbodytowardstheface.•Aseriesofspraysareincorporatedintothesidesoftheintakehoodtocreatethefirstagglomerationimpactpointforthedust/watermixturepriortoimpactfiltrationremovalandalsotoprovideapositivepressureresistancetofirstlycreatean‘aircurtain’andsecondlytoentrainairbornedustoutofthewalkway.ShearerScrubberDesignInsummary,finaldesignincludedthefollowingkeyfeaturesasindicatedbyCFDmodelling:•Thescrubberwasdesignedasacompactmodularunittofitthelimitedspacebetweentherangingarmandtheshearerbody;•Scrubberintakeductfacingtheventilationdirection;•Finewaterspraysembeddedintotheintakeducttoincreasescrubbercollectionareaandadditionalfunctionof‘aircurtain’tosuppressandstreamlinedustparticles;•Scrubberexhaustundertherangingarmandtilted15°towardsthefaceand45°towardthetailgate.ShearerScrubberDesignFigure6.A3DviewofthefinaldesignoftheshearerscrubberFieldTrials•ThefinalfieldtrialstookplaceatBMA’sBroadmeadowMine.•ThedustscrubberwasfittedtothelongwallsheareronmaintenanceshiftinMay2009.•Figure7showstheinstallationofthefinalscrubberdesign.FieldTrialsFigure7.TheinstallationofthefinalscrubberdesignFieldTrialsFigure8.HoodSpraysFilterDischargeCurtainSpraysIntakeSpraysFanHousingIntakeHoodFieldTrials•Forthescrubbertooperateeffectively,ithadtobecapableofbeingstartedandstoppedviatheremotecontrolusedbytheshearerdriver.•Theoilwassuppliedviatheunusedcowlcircuitinthevalvebank.•Theproblemwiththisinitiallywasthatthiscircuitwasnotde-tented.FieldTrialsTheshearerscrubbercreatedseveraloperatingproblems:Problem:•Thescrubbercreatedoverheatingproblemsf