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SpecializedEnglishforchemistryUnitOperationMassTransferandItsApplication•Agroupofoperationsforseparatingthecomponentsofmixturesarebasedonthetranferofmaterialfromonehomogenousphasetoanother.•homogenousadj.同性质的,同类的;•Unlikepurelymechanicalseparations,thesemethodsutilizedifferencesinvaporpressure,solubility,ordiffusivity,notdensityorparticlesize.•mechanical.adj.机械的,机械学的;呆板的;体力的;手工操作的•utilize.vt.利用,使用solubility.n.溶解度;可解决性;溶度•diffusivity.n.扩散能力,扩散率;扩散性•density.n.密度;稠密,浓厚;[物]浓度,比重;愚钝•Thedrivingforceformasstranferisaconcentrationdifferenceoradifferenceinactivity,muchasatemperaturedifferenceoratemperaturegradientprovidesthedrivingforceforheattranfer.•gradient.n.[物]梯度,陡度;(温度、气压等)变化率,梯度变化曲线;英(道路...•adj.倾斜的;[动]步行的,能步行的•••Thesemethods,coveredbythetermmass-tranferoperations,includesuchtechniquesasdistillation,gasabsorption,dehumidification,liquidextraction,leaching,crystallization,membraneseparation,andanumberofothers.•dehumidification.n.除去湿气;除湿•crystallization.n.结晶化•Thefunctionofdistillationistoseparate,byvaporization,aliquidmixtureofmiscibleandvolatilesubstancesintoindividualcomponentsor,insomecases,intogroupsofcomponents.•vaporization.n.蒸发;汽化•miscible.adj.易混合的•volatileadj.易变的,不稳定的;(液体或油)易挥发的;爆炸性的;快活的,轻快的•Theseparationofamixtureofalcoholandwaterintoitscomponents;thatofliquidairintonitrogen,oxygenandargon;andthatofcrudepetroleumintogasoline,kerosene,fueloilandlubricatingstockareexamplesofdistillation.•alcohol.n.乙醇,酒精;含酒精的饮料•argonn.氩•petroleum.n.石油•kerosenen.煤油,火油;灯油;洋油•lubricatingvt.加油润滑;使润滑•vi.润滑•Inpractice,distillationmaybecarriedoutbyeitheroftwoprincipalmethods.•Thefirstmethodisbasedonthereturntothestillincontractwiththevapors.•Thesecondmethodisbasedonthereturnofpartofthecondensatetothestillundersuchconditionsthatthisreturningliquidisbroughtintointimatecontractwiththevaporsontheirwaytothecondenser.•condensaten.冷凝物•intimateadj.亲密的,亲近的;私人的,个人的;内部的;直接的•Eitherofthesemethodsmaybeconductedasacontinuousorasabatchprocess.•Inchemicalengineering,differentialdistillation,steamdistillation,single-stagepartialvaporizationwithoutreflux(flashdistillation)andcontinuousdistillationwithreflux(rectification)areoftenused.•refluxn.逆流,退潮•Ingasabsorptionasolutegasisabsorbedfromaninertgasintoaliquidinwhichthesoluteismoreorlesssoluble.•soluten.溶解物,溶质•Thewashingofammoniafromamixtureofammoniaandairbymeansofliquidwaterisatypicalexample.•ammonia氨;氨水;氨气•Thesoluteissubsequentlyrecoveredfromtheliquidbydistillation,andtheabsorbingliquidcanbeeitherdiscardedorreused.•subsequentlyadv.其后,随后,接着•Whenasoluteistransferredfromthesolventliquidtothegasphase,theoperationisknownasdesorptionorstripping.•Indehumidification,apureliquidispartiallyremovedfromaninertorcarriergasbycondensation.•dehumidification•Usually,thecarriergasisvirtuallyinsolubleintheliquid.•virtuallyadv.实际上,实质上,事实上,几乎;无形中;无形•insolubleadj.不能解决的,不溶的•Removalofwatervaporfromairbycondensationonacoldsurfaceandthecondensationofanorganicvaporsuchascarbontetrachlorideoutofastreamofnitrogenareexamplesofdehumidification.•carbontetrachloride四氯化碳•dehumidification•Inhumidificationoperationsthedirectionoftransferisfromtheliquidtothegasphase.•Inthedryingofsolids,aliquid,usuallywater,isseparatedbytheuseofhot,drygas(usuallyair)andsoiscoupledwiththehumidificationofthegasphase.•Inmembraneseparation,includinggasseparations,reverseosmosis,andultrafiltration,onecomponentofaliquidorgaseousmixturepassesthroughaselectivemembranemorereadilythantheothercomponents.•membrane•reverseosmosis逆渗透;反渗;反渗透;反渗析•ultrafiltration•n.超滤(作用);超过滤•Thefundamentaldrivingforceisthedifferenceinthermodynamicactivity,butinmanycasesthedrivingforcecanbeexpressedasadifferenceinconcentrationorpartialpressure.•partialpressure局部压力;气体分压;分压力;部分压力•Inadsorptionasoluteisremovedfromeitheraliquidoragasthroughcontactwithasolidadsorbent,thesurfaceofwhichhasaspecialaffinityforthesolute.•affinityn.密切关系,姻亲关系;(男女之间的)吸引力,吸引人的异性;类同;类•Ingeneral,dryingasolidmeanstheremovalofarelativelysmallamountofawaterorotherliquidfromthesolidmaterial,toreducethecontentofresidualliquidtoanacceptablelowvalue.•residualliquid•Dryingisusuallythefinalstepinaseriesofoperations,andtheproductfromadryerisoftenreadyforfinalpackaging.•Waterorotherliquidsmayberemovedfromsolidsmechanicallybypressesorcentrifugesorthermallybyvaporization.•mechanicallyadv.机械方面地;机械地;物理上地;呆板地•centrifugesn.离心机(centrifuge的名词复数)••Itisgenerallycheapertoremovewatermechanicallythanthermally,andthusitisadvisabletoreducethemoisturecontentasmuchaspracticablebeforefeedingthematerialtoaheateddryer.•Themoisturecontentofadriedsubstancevariesfromproducttoaproduct.•Dryingisarelativetermandmeansmerelythatthereisreductioninmoisturecontentfromaninitialvaluetosomeacceptablefinalvalue.•relativeadj.相关的;相对的;相互有关的;比较而言的•n.亲属,亲戚;相关物;亲缘植物(或动物);[语法学]关系词•Inliquidextraction,sometimescalledsolventextraction,amixtureoftwocomponentsistreatedbyasolventthatpreferentiallydissolvesoneormoreofthecomponentsinthemixture.•solventextraction溶剂提取•preferentially优先地•Themixturesotreatediscalledtheraffinate,andthesolvent-richphaseiscalledtheextract.•raffinaten.
本文标题:化工专业英语课件四
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