Shinhama Model HI-Flo 20 Flotation Cells – SOLD!

-(4)ShinhamaModelHIF20. -ShinhamaModelHIF16. ProcessImprovement-MinimizedFlotation Afterthefirststageofozonebleaching,stockisbroughtdowntoaconsistencyofonepercentpriortoits introductionintotheflotationsystem.Wehavetwoparallellinesofthreecellswithasinglesecondaryflotationcell inNHandasinglelineandsecondaryinWA. Whiletheoveralldeinkingsystemwasdesignedtoeffectivelyremoveparticlesofupto150micronswiththenew washerdesignandparticlesoverthatsizewiththe.004inchslottedpressurescreens,itwasstillfoundadvantageous forprintingandwritingqualityspecificationstohaveflotationtoremoveinkinthesizerangeoffiftytotwohundred andfiftymicrons. Flotationalsohasalowremovalefficiency(POobservedthisefficiencyintherangeofthirtytoforty percent)forstickiesandmicrostickies.Thedesignutilizedislessdependentonflotationandflotationchemistryfor bothinkandstickiesremovalwhencomparedtomostotherdeinkplantdesigns. Manyotherdeinkplantdesignshaveflotationpriortokneading(ordispersion),afterkneading(ordispersion)and/or flotationsystemsafterasecondarykneadingstage.Considerablecapitaldollarsaretiedupinflotationequipmentfor inkremovalwithpoorresultsforoverallstickiesremoval. ShinhamaFlotationCellsareutilizedinNHandWA.Afterflotationthestockisthensenttothesecond stageofwasherspriortoaKrimaDispersingSystem.Theseflotationcellsactuallyfunctionmuchlikeaverylarge reversecleanerwithairinjection. Itisouropinionthepulpqualityrequiredfortissueandtowelingapplicationstodaycanbeachievedfrommixed officewastewithoutflotationinthesystemifsmallcompromisesonsmalldirtlevelsbetweenprintingandwriting andtissuequalityaremade.Wealsobelievethatinthefutureflotationmaybecomeunnecessaryforprintingand writingqualitywithfurtherimprovementsinwashingandfiberrecovery. Thewashingstageaftertheflotationsystemisalsoanaggressivestagebuttohelpyieldtheaggressivenessofthat washingstagecanbedecreasedtoachievehigheryieldsthroughthechoiceofwhichnozzlesareused,nozzle pressureandthemeshofthefabricinstalledatthatstage. andseparation.Theamountofairandbubblesizedistributionisadjustedwithinthe aerationzone.Inthemixingstage,microturbulanceiscreatedtoincreasecollision fiequencybetweenairbubblesandinkparticles.Airbubblesnsetofomafiothinthe separationzonewhichissubsequentlyremoved£tomthecell.Duetotheincreasing importanceofflotationdeinking,ce11manufachirerscontinuallyupdatethedesignoftheir cellstoreduceenergy,Savespace,irnprovedeinkingefficiencyandreducethelossof valuablefibres. Theinkremovalefficiencyhasbeenshowtoimproveifacombinationof dissolvedanddispersedairisused[32].Flotationisusuallyoperatedusinganumberof cellscomectedinsenesthroughwhichthesuspensionpassesinasteadyflow[16].In addition,therearetypicallytwostagestothefiotationprocess.Theprimarystageisused fordeinking,whileindiesecondarystagethefibresfiomthefiothoftheprimarystage areretrieved. Numerousreviewsofmodemflotationdeinkingce11technologyexistinthe literaturedetailingtheirprinciplesofoperation,configurationandperformance [11,16,18,33-351. Themajordevelopmentsinflotationdeinkingce11technologyhaveoccurredsince theendofthe1970's.Thisevolutioniswelldocumentedintheliterature[Il]. Flotationdeinkingcellsarecurrentlybeingmanufacturedanddistributed LamortFiberprep,Shinarna,ThemoBlackClawson,VoithSulzer,andWemco. Table1summarizestheprimaryfeaturesofsomeofthemainstrearnflotation cells.PleasenotethatsincetheproductionofTable1,BlackClawsonhascornetobe knownasThermoBlackClawson;andVoithandEscherWysshavemergedtobecome knownasVoithSulzer. ShinhamaHi-Flo Anotherflotationce11inuseistheShinamaHi-Floflotationce11[37].This IapanesecellisahydrocyclonesimilartotheKamyrGSC,however,theHi-Floislarger anddoesnothaveaporousmedia.AHi-FlounitisshowninFigure10.