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1、第37卷第8期化学工程Vol.37No.82009年8月CHEMICALENGINEERING(CHINA)Aug.2009双层组合桨搅拌槽内气液微观分散特性李良超,王嘉骏,顾雪萍,冯连芳(浙江大学化学工程与生物工程学系化学工程国家重点实验室,浙江杭州310027)摘要:采用双电导电极探针法对双层组合桨搅拌槽内气液相界面积特性进行了实验研究,考察了通气量、搅拌转速和桨组合对槽内相界面积的影响。结果表明:对于上层桨为上翻斜叶桨和下层桨为凹叶桨的组合,随着通气量的增加,搅拌槽内大部分区域的相界面积增大,但在槽底区域减小。随着搅拌转速的增加,在叶轮区域的相界面积增加明显,而在槽底和液面区
2、域基本不变化。上下层桨的分散能力和气体分布器结构和操作条件密切相关。对于近壁管式气体分布器搅拌槽,在较低通气量下,上层桨对气液分散起着主要作用,而在高通气量下,下层桨的作用增强,起主要作用。带圆盘的搅拌桨对气体具有良好的阻缓作用,不同气速下均具有优异的气液分散能力。关键词:气液搅拌槽;组合桨;气液相界面积;双电导电极探针中图分类号:TQ32.5.15文献标识码:A文章编号:100529954(2009)0820024204Localgas2liquiddispersionpropertiesinadual2impellerstirredvesselLILiang2chao,WANG
3、Jia2jun,GUXue2ping,FENGLian2fang(StateKeyLaboratoryofChemicalEngineering,DepartmentofChemicalandBiochemicalEngineering,ZhejiangUniversity,Hangzhou310027,ZhejiangProvince,China)Abstract:Thelocalgas2liquidinterfacialareainadual2impelleraeratedvesselwasmeasuredwithdouble2tipconductivityprobesfori
4、nvestigatingtheinfluenceofgasinletrate,rotationalspeedandimpellercombinationontheinterfacialareainthevessel.Theresultshowsthatfortheimpellercombinationwithup2pumpingpitchturbineasupperimpellerandconcavebladeturbineaslowerimpeller,thegas2liquidinterfacialareariseswiththeincreaseofthesuperficial
5、velocityinthevessel,expectforthatinthebottomregion.Thegas2liquidinterfacialareaincreasesobviouslyintwoimpellerregionswithincreasingrotationalspeedwhilealmostunchangedinbottomregionandsurfaceregion.Thegasdispersioncapabilitiesofupperandlowerimpellerwereaffectedbythestructureofthespargerandopera
6、tingcondition.Forthevesseldiscussedherein,atthelowgasinletrate,theupperimpellercontributesmoreforthegasdispersion.Withtheincreaseofthegasinletrate,theeffectofthelowerimpellerincreasesandgraduallyshowsthemajoritycontributiontothegasdispersion.Theimpellerswithdisccanpreventtheairescapefromtheves
7、selandperformgoodgasdispersion.Keywords:gas2liquidstirredvessel;impellercombinations;gas2liquidinterfacialarea;double2tipconductivityprobes气液搅拌反应器因其操作灵活,适用性强的优究有着重要意义。点,在工业生产中应用广泛。搅拌反应器内通常采本文对8种搅拌桨组合的气液搅拌槽内气液分用双层桨和多层桨改善气液分散,对搅拌桨进行组散性能进行
