PartⅡMineSafety

LESSON11MethodsofDustControl[教學(xué)內(nèi)容]

IntroductionVentilationWaterspraysDustcollectors

LESSON11MethodsofDustControl[教學(xué)目的]

要求學(xué)生熟記專(zhuān)業(yè)詞匯，達(dá)到英文與中文相互熟練翻譯的程度aerosol['ε?r?s?l]Microflora[,maikr?u'fl?:r?]

respiratory['resp?r?t?ri]abrasion[?'brei??n]

boringextractionlongwallsheareraerosol浮質(zhì)(氣體中的懸浮微粒,如煙,霧等)microflora微植物群respiratory呼吸的abrasion磨損boring打眼；鉆進(jìn)；鉆探extraction開(kāi)采longwall長(zhǎng)壁開(kāi)采法shearer（滾筒式）采煤機(jī)

[教學(xué)目的]

深入理解Ventilation、Watersprays等內(nèi)容，達(dá)到熟練閱讀和正確、通順地翻譯的程度；了解Dustcollectors等內(nèi)容，達(dá)到比較熟練和比較通順?lè)g的程度。LESSON11MethodsofDustControl[教學(xué)重點(diǎn)、難點(diǎn)]

Ventilation[課時(shí)安排]

1.5credithour[授課方法]

講授與討論相結(jié)合LESSON11MethodsofDustControl復(fù)習(xí)舊課1．回憶SHT、chemisorption（化學(xué)吸附作用）專(zhuān)業(yè)詞匯的中文含義；氧化作用（oxidation）、采空區(qū)（goaforgob）、自燃傾向性susceptibilitytospontaneouscombustion英文表達(dá)。2．Pleasedescribetheprimarydangersofconcealedfires.(theevolutionofcarbonmonoxide,theignitionofmethaneandcombustionprogressingintoairwaystoproduceopenfires)LESSON11MethodsofDustControl

Thenaturalatmospherethatwebreathecontainsnotonlyitsgaseousconstituentsbutalsolargenumbersofliquidandsolidparticles.Theseareknownbythegeneric[d?i'nerik]name

aerosols['ε?r?s?l].Theyarisefromacombinationofnaturalandindustrialsourcesincludingcondensation([,k?nden'sei??n]壓縮；凝結(jié)；冷凝)

,smokes,volcanicactivity,soilsandsands,andmicroflora.LESSON11MethodsofDustControlgenericname通用名類(lèi)屬名aerosol浮質(zhì)(氣體中的懸浮微粒,如煙,霧)

microflora微植物群

Thenaturalatmospherethatwebreathecontainsnotonlyitsgaseousconstituentsbutalsolargenumbersofliquidandsolidparticles.Theseareknownbythegenericnameaerosols.我們呼吸的自然大氣中，不僅包含氣態(tài)成分，而且還包含大量的液體和固體微粒。它們統(tǒng)一名稱(chēng)為懸浮微粒。Theyarisefromacombinationofnaturalandindustrialsourcesincludingcondensation,smokes,volcanicactivity,soilsandsands,andmicroflora.懸浮微粒的產(chǎn)生有自然方面又有工業(yè)方面的原因，這包括：凝結(jié)、煙氣、火山活動(dòng)、沙土和微植物群。Mostoftheparticlesaresmallenoughtobeinvisibletothenakedeye.Dustisthetermweuseinreferencetothesolidparticles.Thephysiologiesofair-breathingcreatureshaveevolvedtobeabletodealefficientlywithmostoftheaerosolsthatoccurnaturally.LESSON11MethodsofDustControlphysiology[,fizi'?l?d?i]

生理學(xué)Mostoftheparticlesaresmallenoughtobeinvisibletothenakedeye.Dustisthetermweuseinreferencetothesolidparticles.大部分微粒足夠小，以至于肉眼看不到。我們使用粉塵這個(gè)術(shù)語(yǔ)特指這種固體顆粒。Thephysiologies([,fizi'?l?d?i]生理學(xué),生理機(jī)能)ofair-breathingcreatureshaveevolvedtobeabletodealefficientlywithmostoftheaerosolsthatoccurnaturally.呼吸空氣的生物的生理機(jī)能已進(jìn)化為能夠有效地對(duì)付自然情況下產(chǎn)生的懸浮顆粒。However,withinclosedindustrialenvironments,concentrationsofairborneparticulatesmayreachlevelsthatexceedtheabilityofthehumanrespiratorysystemtoexpeltheminatimely['taimli]

manner.Inparticular,mineraldustsareformedwheneverrockisbrokenbyimpact,abrasion,crushing,cutting,grindingorexplosives.LESSON11MethodsofDustControlHowever,withinclosedindustrialenvironments,concentrationsofairborneparticulatesmayreachlevelsthatexceedtheabilityofthehumanrespiratorysystemtoexpeltheminatimelymanner.然而，在封閉的工業(yè)環(huán)境內(nèi)，懸浮空氣中的微粒濃度可能超過(guò)人類(lèi)呼吸系統(tǒng)能及時(shí)排除它們的程度。Inparticular,mineraldustsareformedwheneverrockisbrokenbyimpact,abrasion[?'brei??n],crushing,cutting,grinding['ɡraindi?]orexplosives尤其是，只要巖石受撞擊、磨損、破碎、切割、研磨或者爆破碎裂時(shí)，就能形成礦塵。Thefragmentsthatareformedareusuallyirregularinshape.Thelargetotalsurfaceareaofdustparticlesmayrender(['rend?]致使)themmoreactivephysically,chemicallyandbiologicallythantheparentmaterial.Thishasanimportantbearingontheabilityofcertainduststoproducelung[l??]diseases.LESSON11MethodsofDustControlhaveabearingon[upon]關(guān)系到...,影響到...renderassistance.給予(提供)援助Thefragmentsthatareformedareusuallyirregularinshape.形成的碎片通常在形狀上是不規(guī)則的。Thelargetotalsurfaceareaofdustparticlesmayrenderthemmoreactivephysically,chemicallyandbiologicallythantheparentmaterial.物質(zhì)破碎后形成的塵?？偙砻娣e增大，從而在物理、化學(xué)和生物方面活性增強(qiáng)。Thishasanimportantbearingontheabilityofcertainduststoproducelungdiseases.這使某些粉塵能夠引起肺病。Thethreemajorcontrolmethodsusedtoreduceairbornedustintunnelsandundergroundmines:ventilation,water,anddustcollectors.LESSON11MethodsofDustControldustcollector吸塵器drycentrifugal[sen'trifjuɡ?l]collector

干式離心除塵器Thethreemajorcontrolmethodsusedtoreduceairbornedustintunnelsandundergroundmines:ventilation,water,anddustcollectors.減少隧道內(nèi)和地下礦山中的懸浮粉塵，有三種主要控制方法：通風(fēng)、水和集塵器。VentilationVentilationairreducesdustthroughbothdilutionanddisplacement.Thedilutionmechanismoperateswhenworkersaresurroundedbyadustcloudandadditionalairservestoreducethedustconcentrationbydilutingthecloud.LESSON11MethodsofDustControlVentilationairreducesdustthroughbothdilutionanddisplacement.通風(fēng)氣流通過(guò)稀釋和置換減少粉塵Thedilutionmechanismoperateswhenworkersaresurroundedbyadustcloudandadditionalairservestoreducethedustconcentrationbydiluting[～e：dai'lju:t]thecloud.當(dāng)工人處于粉塵云的包圍中，稀釋過(guò)程起作用，附加的氣流通過(guò)稀釋塵云，減少粉塵的濃度。Thedisplacementmechanismoperateswhenworkersareupwindofdustsourcesandtheairvelocityishighenoughtoreliablykeepthedustdownwind.LESSON11MethodsofDustControlThedisplacementmechanismoperateswhenworkersareupwindofdustsourcesandtheairvelocityishighenoughtoreliablykeepthedustdownwind.當(dāng)工人位于塵源的上風(fēng)方向，而且氣流速度足夠高，使之能夠可靠地保持粉塵處在下風(fēng)方向時(shí)，置換過(guò)程起作用。DilutionVentilation.Thebasicprinciplebehinddilutionventilationistoprovidemoreairanddilutethedust.Mostofthetimethedustisreducedroughlyinproportiontotheincreaseinairflow,butnotalways.Thecostofandtechnicalbarriers

toincreasedairflowcanbesubstantial,particularlywhereairalreadymovesthroughventilationductworkorshaftsatvelocitiesof3,000ft/minormore.

Substantial(相當(dāng))大的ductworkn.管道系統(tǒng)LESSON11MethodsofDustControl1)DilutionVentilation.Thebasicprinciplebehinddilutionventilationistoprovidemoreairanddilutethedust.1）稀釋通風(fēng)稀釋通風(fēng)的基本原理是提供更多的空氣來(lái)稀釋粉塵。Mostofthetimethedustisreducedroughlyinproportiontotheincreaseinairflow,butnotalways.大多數(shù)情況下，減少的粉塵與增加的風(fēng)量大致成比例，但并不總是這樣。Thecostofandtechnicalbarrierstoincreasedairflowcanbesubstantial,particularlywhereairalreadymovesthroughventilationductworkorshaftsatvelocitiesof3,000ft/minormore.增加風(fēng)量的費(fèi)用和技術(shù)障礙可能是關(guān)鍵，尤其是在流過(guò)通風(fēng)管道或井筒的氣流速度已達(dá)到3000英尺/分（914.4m/min）以上的礦井，更是如此。2)DisplacementVentilation.Thebasicprinciplebehinddisplacementventilationistousetheairflowinawaythatconfines[k?n'fain]thedustsourceandkeepsitawayfromworkersbyputtingdustdownwindoftheworkers.LESSON11MethodsofDustControl2)DisplacementVentilation.2）置換通風(fēng)Thebasicprinciplebehinddisplacementventilationistousetheairflowinawaythatconfinesthedustsourceandkeepsitawayfromworkersbyputtingdustdownwindoftheworkers.置換通風(fēng)的基本原理是利用風(fēng)流約束塵源，使粉塵處在下風(fēng)位置，從而遠(yuǎn)離工人。Everytunnelorminepassagewithanairflowdirectionthatputsdustdownwindofworkersusesdisplacementventilation.Inmines,continuousminerfacesortunnelboringmachinesonexhaustventilationusedisplacementventilation.LESSON11MethodsofDustControlcontinuousminerfaces:連續(xù)采煤機(jī)工作面tunnelboringmachines:隧道掘進(jìn)機(jī)Everytunnelorminepassagewithanairflowdirectionthatputsdustdownwindofworkersusesdisplacementventilation.任一隧道或礦山通道中，如風(fēng)流方向使粉塵處在下風(fēng)方向，使用的就是置換通風(fēng)。Inmines,continuousminerfacesortunnelboringmachinesonexhaustventilationusedisplacementventilation.在礦山中，連續(xù)采煤機(jī)工作面或隧道掘進(jìn)機(jī)的回風(fēng)系統(tǒng)，使用的是置換通風(fēng)Enclosureofadustsource,suchasaconveyorbelttransferpoint,alongwithextractionofdustyairfromtheenclosure,isanotherexampleofdisplacementventilation.Displacementventilationcanbehardtoimplement.LESSON11MethodsofDustControlimplementvt貫徹執(zhí)行Enclosureofadustsource,suchasaconveyorbelttransferpoint,alongwithextractionofdustyairfromtheenclosure,isanotherexampleofdisplacementventilation.在塵源附近，例如運(yùn)輸皮帶轉(zhuǎn)載點(diǎn)，將塵源連同周?chē)鄩m空氣一起抽出去，是置換通風(fēng)的另一個(gè)例子。Displacementventilationcanbehardtoimplement.置換通風(fēng)很難實(shí)現(xiàn)However,ifdonewell,itisthemosteffectivedustcontroltechniqueavailable,anditisworthconsiderableefforttogetitright.Thedifficultyisthatwhenworkersarenearadustsource,say,10to20ftfromthesource,keepingthemupwindrequiresasubstantialairvelocity,typicallybetween60and150ft/min.Thereisnotalwaysenoughairavailabletoachievethesevelocities.LESSON11MethodsofDustControlHowever,ifdonewell,itisthemosteffectivedustcontroltechniqueavailable,anditisworthconsiderableefforttogetitright.然而，如果做得好，置換通風(fēng)是能利用的最有效的粉塵控制技術(shù)，值得付出大量的努力，使其運(yùn)行良好。Thedifficultyisthatwhenworkersarenearadustsource,say,10to20ftfromthesource,keepingthemupwindrequiresasubstantialairvelocity,typicallybetween60and150ft/min.困難之處在于：當(dāng)工人處在塵源附近時(shí)，比方說(shuō)10~20英尺，使他們位于上風(fēng)處需要相當(dāng)大的風(fēng)速（一般要60～150英尺/分）。Thereisnotalwaysenoughairavailabletoachievethesevelocities.并不總有足夠的風(fēng)量能達(dá)到這么大的風(fēng)速。WaterspraysTheroleofwaterspraysinminingisadual['dju:?l]one:(1)wettingofthebrokenmaterialbeingtransportedand(2)airbornecapture.Ofthetwo,wettingofthebrokenmaterialisfarmoreeffective.LESSON11MethodsofDustControlTheroleofwaterspraysinminingisadualone:(1)wettingofthebrokenmaterialbeingtransportedand(2)airbornecapture.Ofthetwo,wettingofthebrokenmaterialisfarmoreeffective.開(kāi)采中噴水的作用是雙重的：（1）濕潤(rùn)正被運(yùn)輸?shù)姆鬯榈奈镔|(zhì)；（2）空中捕獲。這兩個(gè)作用中，濕潤(rùn)粉碎物質(zhì)更加有效。Adequatewettingisextremelyimportantfordustcontrol.Thevastmajorityofdustparticlescreatedduringbreakagearenotreleasedintotheair,butstayattachedtothesurfaceofthebrokenmaterial.Wettingthisbrokenmaterialensuresthatthedustparticlesstayattached.LESSON11MethodsofDustControlAdequatewettingisextremelyimportantfordustcontrol.Thevastmajorityofdustparticlescreatedduringbreakagearenotreleasedintotheair,butstayattachedtothesurfaceofthebrokenmaterial.適度的濕潤(rùn)對(duì)于粉塵控制非常重要。在粉碎過(guò)程中產(chǎn)生的粉塵顆粒大部分沒(méi)有釋放到空氣中，而是附著在粉碎物的表面。Wettingthisbrokenmaterialensuresthatthedustparticlesstayattached.濕潤(rùn)破碎物能夠確保粉塵顆粒保持附著狀態(tài)。Asaresult,addingmorewatercanusually(butnotalways)becountedontoreducedust.Forexample,coalmineoperatorshavebeenabletoreducethedustfromhigherlongwallproductionlevelsbyraisingtheshearerwaterflowratetoanaverageof100gpm.LESSON11MethodsofDustControlAsaresult,addingmorewatercanusually(butnotalways)becountedontoreducedust.因此，通常加水越多越能降低粉塵（但并不總是如此）。Forexample,coalmineoperatorshavebeenabletoreducethedustfromhigherlongwallproductionlevelsbyraisingtheshearerwaterflowratetoanaverageof100gpm例如，煤礦經(jīng)營(yíng)員已能夠通過(guò)提高（滾筒式）采煤機(jī)的水流速度平均達(dá)到100gpm(每分鐘100加侖)，來(lái)減少生產(chǎn)水平較高的長(zhǎng)壁開(kāi)采工作面的粉塵。Comparedtotheamountofcoalmined,onaweightbasis,this100gpmisequivalentto1.9%addedmoisturefromthesheareralone.Unfortunately,excessivemoisturelevelscanalsoresultinahostofmaterialshandlingproblems,operationalheadaches,andproductqualityissues,soanupperlimitonwateruseissometimesreached

ratherquickly.LESSON11MethodsofDustControlComparedtotheamountofcoalmined,onaweightbasis,this100gpmisequivalentto1.9%addedmoisturefromthesheareralone.與開(kāi)采煤的數(shù)量相比，以重量為基礎(chǔ)，由采煤機(jī)每分鐘單獨(dú)加入的100加侖水分等于開(kāi)采煤量的1.9%。Unfortunately,excessivemoisturelevelscanalsoresultinahostofmaterialshandlingproblems,operationalheadaches,andproductqualityissues,soanupperlimitonwateruseissometimesreachedratherquickly.可惜的是，過(guò)高的水分也能導(dǎo)致許多材料的處理問(wèn)題、操作上的不便和產(chǎn)品質(zhì)量問(wèn)題，所以，用水的上限有時(shí)能很快達(dá)到。Asaresult,analternativetosimplyaddingmorewateristoensurethatthebrokenmaterialisbeingwetteduniformly.LESSON11MethodsofDustControlAsaresult,analternativetosimplyaddingmorewateristoensurethatthebrokenmaterialisbeingwetteduniformly.因而，確保粉碎的物質(zhì)能夠得到均勻加濕是替代僅靠增加水量降塵的另一種方法。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.這并不與實(shí)驗(yàn)室試驗(yàn)的結(jié)果完全一樣。在實(shí)際開(kāi)采條件下，以100psi和1-2gpm實(shí)施典型的水噴霧，最多能捕獲30%的風(fēng)載可吸入粉塵。在實(shí)驗(yàn)室的試驗(yàn)中，水噴霧通常限定在管道中，所有的粉塵被迫穿過(guò)水噴霧。However,underactualminingconditions,dustcloudsareunconfined.Inallsprays,themovingdropletsexert[iɡ'z?:t]drag[dr?ɡ]ontheadjacent([?'d?eis?nt]鄰近的)air;thus,spraysacttomovetheair.Becauseofthisairentrainmenteffect,ifasprayisaimedatanunconfineddustcloud,itwillcarryinairthatspreadsthecloud,thusmakingcapturebythespraylessefficient.

LESSON11MethodsofDustControlEntrainmentn.帶走,夾帶However,underactualminingconditions,dustcloudsareunconfined.Inallsprays,themovingdropletsexertdragontheadjacentair;thus,spraysacttomovetheair.Becauseofthisairentrainmenteffect,ifasprayisaimedatanunconfineddustcloud,itwillcarry(被攜帶)

inairthatspreadsthecloud,thusmakingcapturebythespraylessefficient.Attemptstoimprovetheairbornecaptureefficiencyofsprayshavenotmetwithpracticalsuccess.Oneapproachhasbeentoreducedropletsize,basedonthenotionthatcapturebysmallerdropletsismoreefficient.LESSON11MethodsofDustControlNotion['n?u??n]

n.概念,觀念,想法,意見(jiàn),打算,Attemptstoimprovetheairbornecaptureefficiencyofsprayshavenotmetwithpracticalsuccess.Oneapproachhasbeentoreducedropletsize,basedonthenotionthatcapturebysmallerdropletsismoreefficient.DustcollectorsDustcollectorscanplayavaluableroleindustreduction—ifspaceisavailabletolocatethecollectorandifthecollectorefficiencyishigh.Dustcollectorsrangefromlow-volumefiltration[fil'trei??n]systemsusedinthecabs

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