海水淡化MED简介

《海水淡化MED简介》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、MultipleEffectDistillationProcessesforSeaWaterDesalinationThetechnologyIDEM/ENTROPIEistheworldleaderinseawaterdesalinationthroughlowtemperatureSdistillationprocessessuchas:•MultipleEffectDistillation(MED)•MultipleEffectDistillationwithThermalVapourCompression(MED-TVC)•MultipleEffectDistillation

2、withMechanicalVapourCompression(MED-MVC)Non-heatedBASICSONTHEMEDPROCESSseawaterAnMEDevaporatorconsistsofseveralconsecutivecells(oreffects)maintainedDistilledatdecreasinglevelsofpressure(andtemperature)fromthefirst(hot)celltothewaterlastone(cold).Eachcellmainlyconsistsinahorizontaltubesbundle.Th

3、etopofthebundleissprayedwithseawatermake-upthatflowsdownfromtubetotubebygravity(seesketch1).ProducedHeatingsteamisintroducedinsidethetubes.SincetubesarecooledexternallySteambymake-upflow,steamcondensesintodistillate(freshwater)insidethetubes.Atthesametimeseawaterwarmsupandpartlyevaporatesbyreco

4、veringtheSteamcondensationheat(latentheat).DuetoevaporationseawaterslightlyintroducedBrineconcentrateswhenflowingdownthebundleandgivesbrineatthebottomofSketch1thecell.Thevapourraisedbyseawaterevaporationisatalowertemperaturethanheatingsteam.HoweveritcanstillbeusedasheatingmediaforthenextSEAWATE

5、RDISCHARGEeffectwheretheprocessisrepeated.Thedecreasingpressurefromonecelltothenextoneallowsbrineanddistillatetobedrawntothenextcellwherethey60°C50°C40°Cwillflashandreleaseadditionalamountsofvapouratthelowerpressure.STEAMVentThisadditionalvapourwillcondenseintodistillateinsidethenextcell.Conden

6、serCondensateThisprocessisrepeatedinaseriesofeffects(MultipleEffectDistillation)SEAWATERFEED(seesketch2with3effects).Inthelastcell,theproducedsteamcondensesonaconventionalshellandtubesheatexchanger.Thisexchanger,called“distillateBRINEDISTILLATEWATERcondenser”iscooledbysea-water.Attheoutletofthi

7、scondenser,partoftheSketch2warmedsea-waterisusedasmake-upoftheunit,theotherpartisrejectedtothesea.BrineanddistillatearecollectedfromcelltocelltillthelastonefromwheretheyareextractedbycentrifugalpumpsSteamThermocompressorextractedv