外文翻译--21 世纪前半叶矿井提升机在深井中的应用.doc -- 5 元

英文原文Minehoistingindeepshaftsinthe1sthalfof21stCenturyAlfredCarbogno1Keywordsdeepshaft,minehosting,Blairwinder,ropesafetyfactor,drumsizing,skipfactorIntroductionThemineraldepositsareexploitedondeeperanddeeperlevels.Inconnectionwiththis,definitionslikedeeplevelanddeepshaftbecamemoreandmorepopular.Thesedefinitionsconcernthedepthwherespecialrulesregardinganexcavationdriving,exploitation,rockpressurecontrol,liningconstruction,ventilation,undergroundandverticaltransport,workorganizationandeconomicsapply.Ithaspointedoutthatthedeeplevelisaveryrelativedefinitionandshouldbeusedonlywithareferencetoparticularhydrogeological,miningandtechnicalconditionsinamineorcoalfield.Itshouldbealsostrictlydefinedwhatareaofdeeplevelordeepshaftdefinitionsareconsidered.Itcanbeforexamplemininggeoengineering,technologyofexcavationdriving,ventilationtemperature.Itisobviousthatthedeepleveldefinedfromonepointofview,notnecessarilymeansadeeplevelinanotherarea.Accordingto5asadeepminewecantreateachmineifthedepthishigherthan2300mormineraldeposittemperatureishigherthan38ºC.ItiswellknownthatthemostofdeepminesareinSouthAfrica.Usually,theyaregoldordiamondsmines.Economicdepositsofgoldbearingoreareknowntoexistatdepthsupto5000minanumberofSouthAfricaregions.However,duetothedepthandstructureofthereefinsomeareas,previousmethodsofreachingdeeperreefsusingsubverticalshaftsystemswouldnotbeeconomicallyviable.Thus,thelocalminingindustryisactivelyinvestigatingnewtechniquesforasingleliftshaftupto3500mdeepinthenearfutureandprobablyaround5000mafterwards.Whencomparedwiththemaximumlengthofwindcurrentlyinoperationof2500m,itisapparentthatsomesignificantinnovationswillberequired.Themostimportantmatterinthedeepmineistheverticaltransportandtheminehoistingusedintheshaft.Fromtheliterature112resultsthatB.M.R.BlairMultiRopehoistispreferredtobeusedindeepminesinSouthAfrica.Fromtheeconomicpointofview,themostimportantfactorsareconstructionandparametersofwindingropessafetyfactor,mainly,minehoistingdrumscapacity,Thisarticleofinformativecharacterpresentsshortlyabovementionedproblemsbasedontheliteraturedata112.Especially,thepaperwrittenbyM.E.Greenwayisveryinteresting3.Fromtwotransportsystemsusedinthedeepshaft,subverticalandthesingleliftshaftsystems,thesecondoneiscurrentlypreferred.Fig.1.6HoistingInstallationThefrictionhoistupto2100m,singledrumandthedoubledrumclassicandBlairtypedoubledrumhoistareusedindeepshaftsinSouthAfrica.DrumwindersDrumwindersaremostwidelyusedinSouthAfricaandprobablyintheworld.ThreetypesofwindersfallintothiscategorySingledrumwinders,Doubledrumwinders,BlairmultiropewindersBMR.DoubledrumwindersTwodrumsareusedonasingleshaft,withtheropescoiledinoppositedirectionswiththeconveyancesbalancingeachother.OneorbothdrumsareclutchedtotheshaftenablingtherelativeshaftpositionoftheconveyancestobechangedandpermittingthebalancedhoistingfrommultiplelevelsTheBlairMultiRopeSystemBMRIn1957RobertBlairintroducedasystemwherebytheadvantageofthedrumwindercouldbeextendedtotwoormoreropes.Thetworopesystemdevelopedincorporatedatwocompartmentdrumwitharopepercompartmentandtworopesattachedtoasingleconveyance.Healsodevelopedaropetensioncompensatingpulleytobeattachedtotheconveyance.TheDepartmentofMinesallowedthestatutoryfactorofsafetyforhoistingmineralstobe4,275insteadof4,5providedthecapacityfactorineitherropedidnotfallbelowthestatutoryfactorof9.Thisnecessitatedtheuseofsomeformofcompensationtoensureanequitabledistributionofloadbetweenthetworopes.Becausethepulleycompensationislimited,Blairalsodevelopedadevicetodetectthemiscallingonthedrum,asthiscouldcausetheropestomoveatdifferentspeedsandsoaffecttheirloadsharingcapability.Fig.2showsthedepthpayloadcharacteristicsofdoubledrum,BMRandKoepewinders.TheB.M.R.hoistisusedalmostexclusivelyinSouthAfrica,probablybecausetheywereinventedthere,particularlyforthedeepshaftuse.ThereisoneinstallationinEngland.Becauseofthishoistsphysicalcharacteristics,andSouthAfricanminingrulesfavouringitinonerespect,theyareusedmostlyforthedeepshaftmineralhoisting.Thedrumdiametersaresmallerthanthatofanequivalentconventionalhoist,sooneadvantageisthattheyaremoreeasilytakenundergroundforsubshaftinstallations.ABlairhoistisessentiallyaconventionalhoistwithwiderdrums,eachdrumhavingacentreflangethatenablesittocoiltworopesattachedtoaskipviatwoheadsheaves.Theskipconnectionhasabalancewheel,similartoalargemultigrooveVbeltsheave,toallowmoderateropelengthchangesduringwinding.Thesheavescanraiseorlowertoequalizeropetensions.TheBlairhoistsphysicaladvantageisthatthedrumdiametercanbesmallerthanusualand,withtworopestohandletheload,eachropecanbemuchsmaller.Thegovernmentminingregulationspermita5lowersafetyfactoratthesheaveformineralhoistingwithBlairhoists.ThiscameaboutfromademonstrationbythepermitstheBlairhoiststogoalittledeeperthantheotherdo.Ontheotherhand,theminingregulationsrequireadetachinghookabovethecageformanhoisting.Thebalancewheeldoesnotsuitdetachinghooks,soaropecuttingdevicewasinventedtocuttheropesoffforasevereoverwind.ThiswastestedsuccessfullybuttheBlairisnotusedformanwindingonaregularbasis.TheB.M.R.hoisthasbeenbuiltinthreegeneralstylessimilartoconventionalhoists.ThethreestylesareFig.3and4ThegearlessB.M.R.hoistatEastDreifonteinlookssimilartoaninlinehoistexceptthatthedrumsarejoinedmechanicallyandtheyarealittleoutoflinewitheachother.Thisisbecauseeachdrumdirectlyfacesitsownsheavesforthebestfleetangle.Thetwohoistmotorsarefedviathyristorrectifier/inverterunitsfromacommon6.6KVbusbar.Themotorsarethuscoupledelectricallysothattheskipsintheshaftruninbalance,similartoaconventionaldoubledrumhoist.EachmotoralternatesitsactionasaDCgeneratororDCmotor,eitherfeedinginortakingoutenergyfromthesystem.ThegearlessBlaircanberecognizedbytheoffsetdrumsandthefourbrakeunits.Asecondbrakeisalwaysarequirement,eachdrummusthavetwobrakes,becausethetwodrumshavenomechanicalconnectiontoeachother.MostrecentlargeB.M.R.hoistsare4.27or4.57mindiameter,with44.5÷47.6mmropes1.InarrivingatadrumsizethefollowingparametershavebeenusedTheropetobecoiledinfourlayers,Theropetreadpressureatthemaximumstatictensiontobelessthan3,2MPa,ThedrumtoropediameterratioD/dtobegreaterthan127toallowforaropespeedof20m/s.Withtheaboveandaneedtolimittheaxiallengthofthedrums,aropecompartmentof8,5mdiameterby2,8mwide,waschosen.Theuseof5layersofcoiledropecouldreducetheropecompartmentwidthto2,15mbutthisoptionhasbeendiscardedatthisstagebecauseofpossibledetrimentaleffectsontheropelife.