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1、Batchdistillation间歇精馏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
