MembraneFiltrationHandbook

1MembraneFiltrationHandbookPracticalTipsandHintsbyJørgenWagner,B.Sc.Chem.EngSecondEdition,Revision2.November2001Propertyof:________________________________________________________________________________________________________________________________________________________________________©2000,2001PrintedbyOsmonics,Inc.Introduction................................................3DefinitionsandBuzzwords.....................................5TheFourMembraneProcesses..................................7ProductsandProcesses........................................9Membranes-Materials,Structure,Limits.........................10MembraneManufacturers..................................15MembraneModule/ElementDesign...........................16ComparingMembraneModulesandElements...................20LimitationsofMembranesandSystems..........................25SystemComponents.........................................30PumpTypesandPumpSelection...............................38TheSealBetweentheProductandtheWorld...................49ChristmasTreeorMulti-stagePlantDesign........................51PlantFunctions(Start,Stop,Flush).............................54Pretreatment...............................................61PretreatmentMethodsandStrategies............................62WaterSupplyandDrain......................................83ChemicalsforCleaning.ProblematicChemicals....................84CleaningAgentSuppliers...................................86Pasteurization,Disinfection,Sterilization.........................88MeasuringDevices,Flow,Pressure,TDS..........................90PLC,PCandMainFrame.....................................94HowtoControlMembranePlants...............................95CommonControlLoopsinMembraneSystems.....................96HowtoAvoidTSSurgesonStartup.............................104ElectricallyandPneumaticallyOperatedValves...................106ControlofPumps..........................................107OptimizingParametersandPlantOperation......................109DoNot.....................................................112Price,SystemsandMembranes................................113DesigningaSystem.........................................115ListofFigures.............................................118ListofTables..............................................119Index...................................................1202CONTENTS3ThisisthesecondeditionoftheMembraneFiltrationHandbook.InanefforttoimprovetheHandbook,ithasbeenenlargedtoincludethedescriptionofpretreatment,automaticcontrolsandpumps.ThisHandbookistheproductofmanyyearsofexperienceinthefieldofmembranefiltration,anditisintendedtobeamixedbagofinformation.TheHandbook’sgoalistoprovideinformationaboutmanycommonproblemsandhelpanswerquestionsthatnewcomerstomembranefiltrationoftenface.Thebookalsoprovidesinformationhelpfultotheengineerwhodesignsandbuildsmembraneequipmentorworkswithexistingplants.StudentsmayalsofindtheHandbookhelpfulinunderstandingbasicmembraneplantdesignandoperation.Theinformationisbasedonpracticalexperienceratherthantheoreticalcalculationsandspeculations.Consequently,itisnotatraditionaltextbookcommonlyfoundattechnicaluniversities.AlthoughtherearevirtuallynomathematicalcalculationsintheHandbook,itwillstillproveusefultobothindustryanduniversitiesbecauseitcontainsotherpiecesofinformationthatareobvioustothe“oldhand”inmembranefiltrationbutwhich,tothebestofmyknowledge,haveneverbeenpresentedinaprintedformat.ThisHandbookisnotintendedforusebytheabsolutenovicetomembranetechnology.Althoughitdoesdescribeandexplainmembranesandmembranetechnologyinquiteabitofdetail,somefundamentalknowledgeofmembranesandchemistryisassumed.Mostoftheinformationisbasedonexperiencewithflatsheetmembranes(theDDSplate-and-framesystem)andspiralwoundelementsfromOsmonics(DESAL™).Spiralwoundelementsaccountforthevastmajorityofmembraneareasoldworldwide,whilethemarketshareoffibersystems,ceramicsystemsandtubularsystemsisrelativelysmall.Althoughtheyhavetheirplaceinthemembraneworld,thechancesoffiber,ceramicandtubularsystemsbecomingmajorplayersarerelativelysmall.Therefore,littleinforma-tionregardingthesesystemshasbeenincludedintheHandbook.Membranesarebeingputtohardworktoday,buttheyarerelativelyunknowntoconsumerssincetheyareusuallyhiddenwithinindustrialprocesses.Someindustriesdependonmembranesforthemanufacturingofbasicproducts,othersneedmembranestosolvecomplexseparationprocesses,whileothersagainusemembranestomeetenvironmentalstandards.Membranesaresomewhatlikecomputers:fewunderstandthem,onlysomelikethem,butwearealldependentuponthem.Evenifwedonotlikethem,weknowthattheyarenecessarytomakelifeeasierandmorecomfortable.INTRODUCTIONIthastaken35yearstodevelopsufficientlygoodandinexpensivemembranestotreatavarietyofliquids,includingwastewater.However,thereisstillalongwaytogobeforeitisgenerallyknownhowtoengineerandoperatemembraneplants.ItismyhopethatthisHandbookwillhelpavoidsomemistakeswhichcertainlyhavebeenmadebefore.IwanttospeciallythankBjarneNicolaisenforverythoroughtechnicalandlinguisticadv