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1、Batchdistillation間歇精餾FromWikipedia,thefreeencyclopediaJumpto:navigation,?searchBatchdistillation[1]?referstotheuseof?distillation?inbatches,meaningthatamixtureisdistilledtoseparateitintoitscomponentfractionsbeforethedistillationstillisagainchargedwithmoremixtureandth
2、eprocessisrepeated.Thisisincontrastwith?continuousdistillation?wherethefeedstockisaddedandthedistillatedrawnoffwithoutinterruption.Batchdistillationhasalwaysbeenanimportantpartoftheproductionofseasonal,orlowcapacityandhigh-purity?chemicals.Itisaveryfrequent?separatio
3、nprocess?inthe?pharmaceuticalindustry?andin?wastewater?treatmentunits.Batchrectifier[edit]DiagramofaBatchRectifierThesimplestandmostfrequentlyusedbatchdistillationconfigurationisthe?batchrectifier,includingthe?alembic?and?potstill.Thebatchrectifierconsistsofapot(or?r
4、eboiler),rectifyingcolumn,a?condenser,somemeansofsplittingoffaportionofthe?condensed?vapour(distillate)as?reflux,andoneormorereceivers.Thepotisfilledwithliquidmixtureandheated.Vapourflowsupwardsintherectifyingcolumnandcondensesatthetop.Usually,theentirecondensateisin
5、itiallyreturnedtothecolumnas?reflux.Thiscontactingofvapourandliquidconsiderablyimprovestheseparation.Generally,thisstepisnamedstart-up.Thefirstcondensateisthe?head,anditcontainsundesirablecomponents.Thelastcondensateisthe?feints?anditisalsoundesirable,althoughitaddsf
6、lavor.Inbetweenisthe?heart?andthisformsthedesiredproduct.Theheadandfeintsmaybethrownout,refluxed,oraddedtothenextbatchofmash/juice,accordingtothepracticeofthedistiller.Aftersometime,apartoftheoverheadcondensateiswithdrawncontinuouslyasdistillateanditisaccumulatedinth
7、ereceivers,andtheotherpartisrecycledintothecolumnasreflux.Owingtothedifferingvapourpressuresofthedistillate,therewillbeachangeintheoverheaddistillationwithtime,asearlyoninthebatchdistillation,thedistillatewillcontainahighconcentrationofthecomponentwiththehigherrelati
8、vevolatility.Asthesupplyofthematerialislimitedandlightercomponentsareremoved,therelativefractionofheaviercomponentswillincreaseasth
