正做专业英语(L11)

PartⅡMineSafety

LESSON11MethodsofDustControl[教学内容]

IntroductionVentilationWaterspraysDustcollectors

LESSON11MethodsofDustControl[教学目的]

要求学生熟记专业词汇，达到英文与中文相互熟练翻译的程度aerosol['εərəsɔl]Microflora[,maikrəu'flɔ:rə]

respiratory['respərətəri]abrasion[ə'breiʒən]

boringextractionlongwallsheareraerosol浮质(气体中的悬浮微粒,如烟,雾等)microflora微植物群respiratory呼吸的abrasion磨损boring打眼；钻进；钻探extraction开采longwall长壁开采法shearer（滚筒式）采煤机

[教学目的]

深入理解Ventilation、Watersprays等内容，达到熟练阅读和正确、通顺地翻译的程度；了解Dustcollectors等内容，达到比较熟练和比较通顺翻译的程度。LESSON11MethodsofDustControl[教学重点、难点]

Ventilation[课时安排]

1.5credithour[授课方法]

讲授与讨论相结合LESSON11MethodsofDustControl复习旧课1．回忆SHT、chemisorption（化学吸附作用）专业词汇的中文含义；氧化作用（oxidation）、采空区（goaforgob）、自燃倾向性susceptibilitytospontaneouscombustion英文表达。2．Pleasedescribetheprimarydangersofconcealedfires.(theevolutionofcarbonmonoxide,theignitionofmethaneandcombustionprogressingintoairwaystoproduceopenfires)LESSON11MethodsofDustControl

Thenaturalatmospherethatwebreathecontainsnotonlyitsgaseousconstituentsbutalsolargenumbersofliquidandsolidparticles.Theseareknownbythegeneric[dʒi'nerik]name

aerosols['εərəsɔl].Theyarisefromacombinationofnaturalandindustrialsourcesincludingcondensation([,kɔnden'seiʃən]压缩；凝结；冷凝)

,smokes,volcanicactivity,soilsandsands,andmicroflora.LESSON11MethodsofDustControlgenericname通用名类属名aerosol浮质(气体中的悬浮微粒,如烟,雾)

microflora微植物群

Thenaturalatmospherethatwebreathecontainsnotonlyitsgaseousconstituentsbutalsolargenumbersofliquidandsolidparticles.Theseareknownbythegenericnameaerosols.我们呼吸的自然大气中，不仅包含气态成分，而且还包含大量的液体和固体微粒。它们统一名称为悬浮微粒。Theyarisefromacombinationofnaturalandindustrialsourcesincludingcondensation,smokes,volcanicactivity,soilsandsands,andmicroflora.悬浮微粒的产生有自然方面又有工业方面的原因，这包括：凝结、烟气、火山活动、沙土和微植物群。Mostoftheparticlesaresmallenoughtobeinvisibletothenakedeye.Dustisthetermweuseinreferencetothesolidparticles.Thephysiologiesofair-breathingcreatureshaveevolvedtobeabletodealefficientlywithmostoftheaerosolsthatoccurnaturally.LESSON11MethodsofDustControlphysiology[,fizi'ɔlədʒi]

生理学Mostoftheparticlesaresmallenoughtobeinvisibletothenakedeye.Dustisthetermweuseinreferencetothesolidparticles.大部分微粒足够小，以至于肉眼看不到。我们使用粉尘这个术语特指这种固体颗粒。Thephysiologies([,fizi'ɔlədʒi]生理学,生理机能)ofair-breathingcreatureshaveevolvedtobeabletodealefficientlywithmostoftheaerosolsthatoccurnaturally.呼吸空气的生物的生理机能已进化为能够有效地对付自然情况下产生的悬浮颗粒。However,withinclosedindustrialenvironments,concentrationsofairborneparticulatesmayreachlevelsthatexceedtheabilityofthehumanrespiratorysystemtoexpeltheminatimely['taimli]

manner.Inparticular,mineraldustsareformedwheneverrockisbrokenbyimpact,abrasion,crushing,cutting,grindingorexplosives.LESSON11MethodsofDustControlHowever,withinclosedindustrialenvironments,concentrationsofairborneparticulatesmayreachlevelsthatexceedtheabilityofthehumanrespiratorysystemtoexpeltheminatimelymanner.然而，在封闭的工业环境内，悬浮空气中的微粒浓度可能超过人类呼吸系统能及时排除它们的程度。Inparticular,mineraldustsareformedwheneverrockisbrokenbyimpact,abrasion[ə'breiʒən],crushing,cutting,grinding['ɡraindiŋ]orexplosives尤其是，只要岩石受撞击、磨损、破碎、切割、研磨或者爆破碎裂时，就能形成矿尘。Thefragmentsthatareformedareusuallyirregularinshape.Thelargetotalsurfaceareaofdustparticlesmayrender(['rendə]致使)themmoreactivephysically,chemicallyandbiologicallythantheparentmaterial.Thishasanimportantbearingontheabilityofcertainduststoproducelung[lʌŋ]diseases.LESSON11MethodsofDustControlhaveabearingon[upon]关系到...,影响到...renderassistance.给予(提供)援助Thefragmentsthatareformedareusuallyirregularinshape.形成的碎片通常在形状上是不规则的。Thelargetotalsurfaceareaofdustparticlesmayrenderthemmoreactivephysically,chemicallyandbiologicallythantheparentmaterial.物质破碎后形成的尘粒总表面积增大，从而在物理、化学和生物方面活性增强。Thishasanimportantbearingontheabilityofcertainduststoproducelungdiseases.这使某些粉尘能够引起肺病。Thethreemajorcontrolmethodsusedtoreduceairbornedustintunnelsandundergroundmines:ventilation,water,anddustcollectors.LESSON11MethodsofDustControldustcollector吸尘器drycentrifugal[sen'trifjuɡəl]collector

干式离心除尘器Thethreemajorcontrolmethodsusedtoreduceairbornedustintunnelsandundergroundmines:ventilation,water,anddustcollectors.减少隧道内和地下矿山中的悬浮粉尘，有三种主要控制方法：通风、水和集尘器。VentilationVentilationairreducesdustthroughbothdilutionanddisplacement.Thedilutionmechanismoperateswhenworkersaresurroundedbyadustcloudandadditionalairservestoreducethedustconcentrationbydilutingthecloud.LESSON11MethodsofDustControlVentilationairreducesdustthroughbothdilutionanddisplacement.通风气流通过稀释和置换减少粉尘Thedilutionmechanismoperateswhenworkersaresurroundedbyadustcloudandadditionalairservestoreducethedustconcentrationbydiluting[～e：dai'lju:t]thecloud.当工人处于粉尘云的包围中，稀释过程起作用，附加的气流通过稀释尘云，减少粉尘的浓度。Thedisplacementmechanismoperateswhenworkersareupwindofdustsourcesandtheairvelocityishighenoughtoreliablykeepthedustdownwind.LESSON11MethodsofDustControlThedisplacementmechanismoperateswhenworkersareupwindofdustsourcesandtheairvelocityishighenoughtoreliablykeepthedustdownwind.当工人位于尘源的上风方向，而且气流速度足够高，使之能够可靠地保持粉尘处在下风方向时，置换过程起作用。DilutionVentilation.Thebasicprinciplebehinddilutionventilationistoprovidemoreairanddilutethedust.Mostofthetimethedustisreducedroughlyinproportiontotheincreaseinairflow,butnotalways.Thecostofandtechnicalbarriers

toincreasedairflowcanbesubstantial,particularlywhereairalreadymovesthroughventilationductworkorshaftsatvelocitiesof3,000ft/minormore.

Substantial(相当)大的ductworkn.管道系统LESSON11MethodsofDustControl1)DilutionVentilation.Thebasicprinciplebehinddilutionventilationistoprovidemoreairanddilutethedust.1）稀释通风稀释通风的基本原理是提供更多的空气来稀释粉尘。Mostofthetimethedustisreducedroughlyinproportiontotheincreaseinairflow,butnotalways.大多数情况下，减少的粉尘与增加的风量大致成比例，但并不总是这样。Thecostofandtechnicalbarrierstoincreasedairflowcanbesubstantial,particularlywhereairalreadymovesthroughventilationductworkorshaftsatvelocitiesof3,000ft/minormore.增加风量的费用和技术障碍可能是关键，尤其是在流过通风管道或井筒的气流速度已达到3000英尺/分（914.4m/min）以上的矿井，更是如此。2)DisplacementVentilation.Thebasicprinciplebehinddisplacementventilationistousetheairflowinawaythatconfines[kən'fain]thedustsourceandkeepsitawayfromworkersbyputtingdustdownwindoftheworkers.LESSON11MethodsofDustControl2)DisplacementVentilation.2）置换通风Thebasicprinciplebehinddisplacementventilationistousetheairflowinawaythatconfinesthedustsourceandkeepsitawayfromworkersbyputtingdustdownwindoftheworkers.置换通风的基本原理是利用风流约束尘源，使粉尘处在下风位置，从而远离工人。Everytunnelorminepassagewithanairflowdirectionthatputsdustdownwindofworkersusesdisplacementventilation.Inmines,continuousminerfacesortunnelboringmachinesonexhaustventilationusedisplacementventilation.LESSON11MethodsofDustControlcontinuousminerfaces:连续采煤机工作面tunnelboringmachines:隧道掘进机Everytunnelorminepassagewithanairflowdirectionthatputsdustdownwindofworkersusesdisplacementventilation.任一隧道或矿山通道中，如风流方向使粉尘处在下风方向，使用的就是置换通风。Inmines,continuousminerfacesortunnelboringmachinesonexhaustventilationusedisplacementventilation.在矿山中，连续采煤机工作面或隧道掘进机的回风系统，使用的是置换通风Enclosureofadustsource,suchasaconveyorbelttransferpoint,alongwithextractionofdustyairfromtheenclosure,isanotherexampleofdisplacementventilation.Displacementventilationcanbehardtoimplement.LESSON11MethodsofDustControlimplementvt贯彻执行Enclosureofadustsource,suchasaconveyorbelttransferpoint,alongwithextractionofdustyairfromtheenclosure,isanotherexampleofdisplacementventilation.在尘源附近，例如运输皮带转载点，将尘源连同周围多尘空气一起抽出去，是置换通风的另一个例子。Displacementventilationcanbehardtoimplement.置换通风很难实现However,ifdonewell,itisthemosteffectivedustcontroltechniqueavailable,anditisworthconsiderableefforttogetitright.Thedifficultyisthatwhenworkersarenearadustsource,say,10to20ftfromthesource,keepingthemupwindrequiresasubstantialairvelocity,typicallybetween60and150ft/min.Thereisnotalwaysenoughairavailabletoachievethesevelocities.LESSON11MethodsofDustControlHowever,ifdonewell,itisthemosteffectivedustcontroltechniqueavailable,anditisworthconsiderableefforttogetitright.然而，如果做得好，置换通风是能利用的最有效的粉尘控制技术，值得付出大量的努力，使其运行良好。Thedifficultyisthatwhenworkersarenearadustsource,say,10to20ftfromthesource,keepingthemupwindrequiresasubstantialairvelocity,typicallybetween60and150ft/min.困难之处在于：当工人处在尘源附近时，比方说10~20英尺，使他们位于上风处需要相当大的风速（一般要60～150英尺/分）。Thereisnotalwaysenoughairavailabletoachievethesevelocities.并不总有足够的风量能达到这么大的风速。WaterspraysTheroleofwaterspraysinminingisadual['dju:əl]one:(1)wettingofthebrokenmaterialbeingtransportedand(2)airbornecapture.Ofthetwo,wettingofthebrokenmaterialisfarmoreeffective.LESSON11MethodsofDustControlTheroleofwaterspraysinminingisadualone:(1)wettingofthebrokenmaterialbeingtransportedand(2)airbornecapture.Ofthetwo,wettingofthebrokenmaterialisfarmoreeffective.开采中喷水的作用是双重的：（1）湿润正被运输的粉碎的物质；（2）空中捕获。这两个作用中，湿润粉碎物质更加有效。Adequatewettingisextremelyimportantfordustcontrol.Thevastmajorityofdustparticlescreatedduringbreakagearenotreleasedintotheair,butstayattachedtothesurfaceofthebrokenmaterial.Wettingthisbrokenmaterialensuresthatthedustparticlesstayattached.LESSON11MethodsofDustControlAdequatewettingisextremelyimportantfordustcontrol.Thevastmajorityofdustparticlescreatedduringbreakagearenotreleasedintotheair,butstayattachedtothesurfaceofthebrokenmaterial.适度的湿润对于粉尘控制非常重要。在粉碎过程中产生的粉尘颗粒大部分没有释放到空气中，而是附着在粉碎物的表面。Wettingthisbrokenmaterialensuresthatthedustparticlesstayattached.湿润破碎物能够确保粉尘颗粒保持附着状态。Asaresult,addingmorewatercanusually(butnotalways)becountedontoreducedust.Forexample,coalmineoperatorshavebeenabletoreducethedustfromhigherlongwallproductionlevelsbyraisingtheshearerwaterflowratetoanaverageof100gpm.LESSON11MethodsofDustControlAsaresult,addingmorewatercanusually(butnotalways)becountedontoreducedust.因此，通常加水越多越能降低粉尘（但并不总是如此）。Forexample,coalmineoperatorshavebeenabletoreducethedustfromhigherlongwallproductionlevelsbyraisingtheshearerwaterflowratetoanaverageof100gpm例如，煤矿经营员已能够通过提高（滚筒式）采煤机的水流速度平均达到100gpm(每分钟100加仑)，来减少生产水平较高的长壁开采工作面的粉尘。Comparedtotheamountofcoalmined,onaweightbasis,this100gpmisequivalentto1.9%addedmoisturefromthesheareralone.Unfortunately,excessivemoisturelevelscanalsoresultinahostofmaterialshandlingproblems,operationalheadaches,andproductqualityissues,soanupperlimitonwateruseissometimesreached

ratherquickly.LESSON11MethodsofDustControlComparedtotheamountofcoalmined,onaweightbasis,this100gpmisequivalentto1.9%addedmoisturefromthesheareralone.与开采煤的数量相比，以重量为基础，由采煤机每分钟单独加入的100加仑水分等于开采煤量的1.9%。Unfortunately,excessivemoisturelevelscanalsoresultinahostofmaterialshandlingproblems,operationalheadaches,andproductqualityissues,soanupperlimitonwateruseissometimesreachedratherquickly.可惜的是，过高的水分也能导致许多材料的处理问题、操作上的不便和产品质量问题，所以，用水的上限有时能很快达到。Asaresult,analternativetosimplyaddingmorewateristoensurethatthebrokenmaterialisbeingwetteduniformly.LESSON11MethodsofDustControlAsaresult,analternativetosimplyaddingmorewateristoensurethatthebrokenmaterialisbeingwetteduniformly.因而，确保粉碎的物质能够得到均匀加湿是替代仅靠增加水量降尘的另一种方法。Underactualminingconditions,thetypicalwatersprayoperatingat100psiand1-2gpmgivesnomorethan30%airbornecaptureofrespirabledust.Thisisnotasgoodaslabtestswouldleadonetobelieve.Inlabtests,sprayswereusuallyconfinedinaduct,andallofthedustwasforcedtopassthroughthespray.LESSON11MethodsofDustControlpsi:PoundsperSquareInch.磅/平方英尺gpm:GallonsPerMinuteUnderactualminingconditions,thetypicalwatersprayoperatingat100psi（poundspersquareinch）and1-2gpmgivesnomorethan30%airbornecaptureofrespirabledust.Thisisnotasgoodaslabtestswouldleadonetobelieve.Inlabtests,sprayswereusuallyconfinedinaduct,andallofthedustwasforcedtopassthroughthespray.这并不与实验室试验的结果完全一样。在实际开采条件下，以100psi和1-2gpm实施典型的水喷雾，最多能捕获30%的风载可吸入粉尘。在实验室的试验中，水喷雾通常限定在管道中，所有的粉尘被迫穿过水喷雾。However,underactualminingconditions,dustcloudsareunconfined.Inallsprays,themovingdropletsexert[iɡ'zə:t]drag[dræɡ]ontheadjacent([ə'dʒeisənt]邻近的)air;thus,spraysacttomovetheair.Becauseofthisairentrainmenteffect,ifasprayisaimedatanunconfineddustcloud,itwillcarryinairthatspreadsthecloud,thusmakingcapturebythespraylessefficient.

LESSON11MethodsofDustControlEntrainmentn.带走,夹带However,underactualminingconditions,dustcloudsareunconfined.Inallsprays,themovingdropletsexertdragontheadjacentair;thus,spraysacttomovetheair.Becauseofthisairentrainmenteffect,ifasprayisaimedatanunconfineddustcloud,itwillcarry(被携带)

inairthatspreadsthecloud,thusmakingcapturebythespraylessefficient.Attemptstoimprovetheairbornecaptureefficiencyofsprayshavenotmetwithpracticalsuccess.Oneapproachhasbeentoreducedropletsize,basedonthenotionthatcapturebysmallerdropletsismoreefficient.LESSON11MethodsofDustControlNotion['nəuʃən]

n.概念,观念,想法,意见,打算,Attemptstoimprovetheairbornecaptureefficiencyofsprayshavenotmetwithpracticalsuccess.Oneapproachhasbeentoreducedropletsize,basedonthenotionthatcapturebysmallerdropletsismoreefficient.DustcollectorsDustcollectorscanplayavaluableroleindustreduction—ifspaceisavailabletolocatethecollectorandifthecollectorefficiencyishigh.Dustcollectorsrangefromlow-volumefiltration[fil'treiʃən]systemsusedinthecabs

[kæb]ofminingequipmenttohigh-volumewetcollectorsusedoncontinuousminersincoalmines.LESSON11MethodsofDustControlDustcollectorscanplayavaluableroleindustreduction—ifspaceisavailabletolocatethecollectorandifthecollectorefficiencyishigh.Dustcollectorsrangefromlow-volumefiltrationsystemsusedinthecabsofminingequipmenttohigh-volumewetcollectorsusedoncontinuousminersincoalmines.Itisimportanttorecognizethattheefficiencyofadustcollectoristhefiltrationefficiencyoftheunittimesthecaptureefficiencyofitsinlet['inlet].Forcollectorsproperlydesignedtotraprespirabledust,thefiltrationefficiencyisusuallyquitehigh,inthe90%-95%range.LESSON11MethodsofDustControlItisimportanttorecognizethattheefficiencyofadustcollectoristhefiltrationefficiencyoftheunittimesthecaptureefficiencyofitsinlet.Forcollectorsproperlydesignedtotraprespirabledust,thefiltration