《专业英语阅读》PPT课件.ppt

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1、Unit1UnitOperationsArp26th，2011Ying,Xiaoguanglesson1ClassificationofUnitOperationsFluidflowThisconcernstheprinciplesthatdeterminetheflowortransportationofanyfluidfromonepointtoanother.HeattransferThisunitoperationdealswiththeprinciplesthatgovernaccumula

2、tionandtransferofheatandenergyfromoneplacetoanother.EvaporationThisisaspecialcaseofheattransfer,whichdealswiththeevaporationofavolatilesolventsuchaswaterfromanonvolatilesolutesuchassaltoranyothermaterialinsolution.DryingInthisoperationvolatileliquids,usu

3、allywater,areremovedfromsolidmaterialsDistillationThisisanoperationwherebycomponentsofaliquidmixtureareseparatedbyboilingbecauseoftheirdifferencesinvaporpressure.AbsorptionInthisprocessacomponentisremovedfromagasstreambytreatmentwithaliquid.Membranesepar

4、ationThisprocessinvolvesthediffusionofasolutefromaliquidorgasthroughasemipermeablemembranebarriertoanotherfluid.Liquid-liquidextractionInthiscaseasoluteinaliquidsolutionisremovedbycontactingwithanotherliquidsolventwhichisrelativelyimmiscible(不混溶的)withthe

5、solution.Liquid-solidleaching(浸提)Thisinvolvestreatingafinelydividedsolidwithaliquidthatdissolvesoutandremovesasolutecontainedinthesolid.CrystallizationThisconcernstheremovalofasolutesuchasasaltfromasolutionbyprecipitating(沉淀)thesolutefromthesolution.Mech

6、anicalphysicalseparationTheseinvolvesseparationofsolids,liquids,orgasesbymechanicalmeans,suchasfiltration,settling,andsizereduction,whichareoftenclassifiedasseparateunitoperations.Lesson2FractionaldistillationFractionaldistillationistheseparationofamixtu

7、reofcompoundsbytheirboilingpoint,byheatingtohighenoughtemperatures.FractionalDistillationinaLaboratoryApparatusconicalflask1.Theapparatusisassembledasinthediagram.Themixtureisputintotheroundbottomedflaskalongwithafewantibumpinggranules(沸石),andthefraction

8、atingcolumnisfittedintothetop.2.Asthemixtureboils,vaporrisesupthecolumn.Thevaporcondensesontheglassplatformsinsidethecolumn,andrunsbackdownintotheliquidbelow,refluxingdistillate.3.Onlythemostvolatileofthevaporsstaysingaseo