会员注册 | 登录 | 微信快捷登录 支付宝快捷登录 QQ登录 微博登录 | 帮助中心 人人文库renrendoc.com美如初恋!
站内搜索 百度文库

热门搜索: 直缝焊接机 矿井提升机 循环球式转向器图纸 机器人手爪发展史 管道机器人dwg 动平衡试验台设计

外文翻译--一种新型风动式选粉机对极细粉末分级的研究 英文版.pdf外文翻译--一种新型风动式选粉机对极细粉末分级的研究 英文版.pdf -- 5 元

宽屏显示 收藏 分享

资源预览需要最新版本的Flash Player支持。
您尚未安装或版本过低,建议您

ClassificationofultrafinepowderbyanewpneumatictypeclassifierHiroshiMorimoto,ToshihikoShakouchiGraduateSchoolofEngineering,MieUniversity,Kamihamacho1515,Tsu,Mie5148507,JapanReceived23March2002receivedinrevisedform1September2002accepted14November2002AbstractRecently,therearegreatrequirementsforultrafinepowderinfieldsthatuseadvancedmaterials,forexample,electricpartsinInformationTechnologyITindustry.Especially,therequestforthediametercontrolofultrafinepowderisincreasing.Pneumatictypeultrafinepowderseparator,classifier,isoneoftheequipmentwhichmeetthisrequest.Butthereisnoclarifiedstudyontheflowconditionthatrealizeshighperformance.Inthisstudy,anewpneumatictypeultrafineclassifierisproposedandtherelationbetweentheperformanceandtheflowconditionisinvestigatedbyflowvisualizationwiththetuftgridandoildotmethodsandthemeasurementofgasvelocity.Basedontheresults,itwasknownthatthenewclassifierhasalargeswirlingflowvelocitywhichisabletoclassifyultrafineparticlesaccurately.KeywordsGas–solidflowPneumaticpowderclassifierUltrafinepowderFlowvisualizationVelocitydistribution1.IntroductionAdvancedindustrialmaterials,suchasfineceramics,ultraconductormaterial,magneticfines,tonerusedforprinters,etc.,areusuallyintheformoffinepowder.Recently,duetotherapidprogressoftheInformationTechnologyITindustry,therequirementtocontroltheparticlediameter,suchastomakefinepowderpulverizationuniformlytoarrangefinepowderedparticlesclassificationofinorganicandorganicdrymaterials,haschangeddrasticallyfromtheparticlesizeofAmordertosubAmorderhereafter,itiscalledultrafinepowder,1Amorless.Now,manytypesofpowderclassifiersarecommerciallyavailable.Forexample,therearecyclonetypeseparators1,crossflowairtypeclassifiers2andimpellerwheeltypeclassifiers3,whichareusedwidelyinthemanufacturingprocessofpowderedmaterials,althoughtheclassifiercanclassifyultrafinepowderindryconditionsaccuratelyandthereisnosuchclassifierinindustrialfields.Inthisstudy,anewpneumatictypeofultrafinepowderclassifierhereafter,itiscalledthenewclassifierisintroduced.Thenewclassifierusesanewtypeofswirlingflowandsatisfiestheabovementionedrequirements.Itwasintendedtorealizeanidealflowfieldtogivealargecentrifugalforceforallsuppliedfinepowderthatcanbeclassifiedaccuratelyinultrafinepowder.Theflowconditionwasconfirmedbyflowvisualizationandobservation,themeasurementofgasvelocitydistributionandtheexperimentofclassification.Itisimportanttounderstandtheflowconditionquantitativelywhenrealizingaclassifierwithhighperformance.Inaddition,theclassificationperformancewasconfirmedbyatestthatusessomefineparticles,suchascalciumcarbonateandtungstendioxide.Asaresult,itwasknownthatthenewpneumatictypeclassifiercanclassifyanultrafinepowderofsubAm.2.Conceptofultrafinepowderclassification,experimentalsetupandprocedure2.1.ConceptandexperimentalsetupInordertoclassifyanultrafineparticle,itisveryimportanttoexertalargecentrifugalforceoneachparticle.Thenewclassifierhasaconicalshapedclassificationzoneandthenthemostofswirlingflowpassesthroughthelouver,whichflowsupward,andthenthetangentialvelocityacceleratesrapidlybecausetheswirlingradiusbecomessmaller.Everyparticlecanbegivenalargecentrifugalforcebyalargetangentialvelocity.Thenewclassifierhasnotonlyaveryhighclassificationperformancebutalsoalargefeedrateofmaterial.TheconventionalfinepowderclassiCorrespondingauthor.Tel.81592319384fax81592319663.Emailaddressanglerict.ne.jpH.Morimoto.PowderTechnology131200371–79fierhasahighclassificationperformancebutthefeedrateisverysmallingeneral.Fig.1showsthepneumatictypeclassifier.Theclassifierusesonlyaswirlingflowanddoesnothaveanymovingpartsinsideit.Theclassifierconsistsofadispersionzonei,classificationzoneofconicalshapeiiandguidevanezoneiii.Powderedmaterialissuppliedintothedispersionzoneandtheairisintroducedfromtheoutsideintotheclassifierpassingthroughtheguidevanehereafter,itiscalledthelouver,whichis20mminheightand77mminlengthandgeneratesaswirlingflow.Thedispersionzonehasamainnozzletosupplymaterialof12mmindiameter,thedispersionnozzleanddispersioncone.Theclassificationzonehasalowersurfaceofangleb20jintheclassificationzoneandtheuppersurfaceofanglea60jalsointheclassificationzone.Moreover,thediameteroftheexitpipeD60mmfortheswirlingairflowwithfinepowderexistsatthecenterofthelowersurfaceintheclassificationzoneandtheexhaustslit,5mminwidth,forcoarsepowderexistsattheoutercircumference.Thedispersionconesetatthecenterofthetopintheclassificationzonepreventsthesuppliedmaterialfromflowingtotheexitdirectly.Fig.2showstheschematicdiagramoftheexperimentalsetup.AirflowAirIwithfinepowder,airflowAirIIfordispersionofpowderandairflowAirIIIfromthelouveraresuckedbyblower,andalloftheairflowisexhaustedtotheoutsidethroughbagfilter.Acenteraxisoftheclassifierisassumedtobethexcoordinate,andrcoordinateintheradialseeFig.1.ThepowderladenAirIflowsintotheconicalshapedclassificationzonefromthetopandintheC0xdirection,gravitationaldirection,afterdispersedwellbytheAirII.TheAirIIIflowsintotheclassificationzoneuniformlythroughthepassagebetweenthelouversthataresetatthebottomouterpartevenly.The16piecesoflouveraresetupevenlyinthecircumferentialdirectionA–Asection,andthewidthofthepassagebetweenthelouversischangeableintherangeof1to7mm.Thesettinganglehiofthelouverdependsonthewidthofthepassagebetweenthelouversandcanbesetintherangeof7jto15j.Theswirlingflowisproducedbytheflowthatpassesthroughthepassagebetweenthelouvers.ThevolumetricflowrateratioofAirI,AirIIandAirIIIis7390.Then,theflowcharacteristicsoftheswirlingflowintheclassificationzonedependsontheflowofAirIII.Moreover,theswirlingflowintheclassificationzoneformsathreedimensionalcomplexflowfieldwhereacentrifugalforceisexerted.TheAirIIIflowsintheradialdirectioncenterdirectionoftheconicwhileswirling,andtheflowthatreachestothecenterisexhaustedfromtheexit.Ontheotherhand,therawpowderedmaterialwithafixedquantityandAirIisintroducedintothedispersionzonewithswirlingfromthemainnozzleafterdispersingwellbyAirII.Theswirlingdirectionisthesamedirectionasthatintheclassificationzone.TherawpowderedmaterialFig.1.Ultrafinepowderclassifier.H.Morimoto,T.Shakouchi/PowderTechnology131200371–7972introducedintotheclassificationzonereceivesalargecentrifugalforceintheupperregionoftheconic,andthenthecoarsepowderisseparatedintheradialdirectionandiscollectedfromtheslitatthebottomandoutsideoftheclassificationzonetothehopper.Thedescendingflowwiththeultrafinepowderinthevicinityofthecenteroftheclassificationzoneflowsoutfromtheexitandthebagfiltercollectsthepowder.2.2.MeasurementofvelocitydistributionTheexperimentalsetupusedtomeasurethevelocitydistributioninthisclassifierisshowninFig.3.Ayawmeter4of1.0mmindiameterand300mminlengthwithasingleholeof0.5mmindiameterwasinsertedinrightangleddirectionraxistothecenteraxisxaxisintheclassificationzone.Thevelocitydistributionwasmeasuredinthesectionoftheraxisatx105mm.Theyawmetercanmovealongtheraxisandrotatearounditsownaxis,andcanmeasurethevelocityintherandxdirectionsatanarbitraryradiusposition.Thehorizontaldirectionwasassumedtobeh0j,itwasrotateduptoh120jatevery10j240jintotalvertically,andthepressurewasmeasuredbyusingamercurycolumnmanometerFig.2,.Inthiscase,theamountofallinflowairwasQ6.5m3/minconstant,andthewidthofthepassagebetweenthelouverswaschangedatFig.3.Velocitymeasurementbyyawmeter.Fig.2.Experimentalsetup.H.Morimoto,T.Shakouchi/PowderTechnology131200371–7973wl3,5,and7mm.Theflowdirectionangleinupanddownateachmeasurementpositionwascalculatedfromthepressuredistribution,andthevelocityoftheairflowwascalculatedfromthestaticanddynamicpressures.Everyexperimentforvelocitydistributionwascarriedoutonlyforasinglephase,airflowwhichdidnotwithfinepowder.3.FlowvisualizationsandobservationTounderstandtheflowconditionintheclassificationzonequalitatively,flowvisualizationandobservationbythetuftgridmethodandtheoildotmethodweredone.3.1.TuftgridmethodTheshapeofthetuftgrid5andthetuftusedareshowninFig.4.Theframewasmadebyastainlesssteelstickof/3.0mmandthewireof/0.3mmwasstringedlikethegrid.Thetuftwasmadeofnylonfinefiberwithalength15mmwasbondedatthe73nodesofthewire.Theframewassetattheradiuspositionofasectiononthexaxisintheclassificationzone.Thetuftgridwassetintheclassifiermadebytransparentacrylicresin,andtheexperimentwascarriedoutforonlytheairflow.Theinclinationandfluctuationofthetufteffectedbytheswirlingflowwereobservedfromthehorizontalandperpendiculardirections,andtheywererecordedbyavideocameraFig.2,.3.2.OildotmethodThe35oildotsontheuppersurfaceandthe20pointsonthelowersurfaceintheclassificationzoneatradialtwoplacesevery180jwereusedtofindouttheflowdirectiononthesurfaces.TheamountofallairinflowisQ3.5m3/min,andtheaverageinflowvelocityisVi58m/swl3mmatthelouver,andthetrajectoryoftheoildotaftertheexperimentforonlytheairwasobserved.Theswirlingangleoftheflowonthesurfacewasmeasuredfromthetrajectoryoftheoildot.Themixtureconsistedof77.4liquidparaffininvolume,6.5linseedoil,6.5oleicacidsand9.6titaniawasusedaswhitecoloreddye.4.ApproximatetheoryforcuttingsizeThecuttingsizeoftheclassifierclassificationpointwasapproximatelycalculatedasfollows.Fig.5showsanimitativechartoftheprinciple.Consideringadynamicforcethatexertsontheparticlesuppliedintheclassificationzone,theequationofthemotionofasinglesphericalparticleswirlingonanarbitraryradiuspositionisshownasfollowsp6D3pqpdVrdt¼p6D3pðqpC0qÞrx2C0CDp8D2pqV2rð1ÞTheterminalvelocityoftheparticlecanbedrawnfromEq.1asfollowsdVrdt0Vrt¼ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi4ðqpC0qÞDprx23qCDsð2ÞMoreover,whentheparticleReynoldsnumberReisintheStokesregion,thedragcoefficientoftheparticleisCD24/ReforRe2,andthenVrt¼ðqpC0qÞD2prx218lð3ÞNow,sincethetangentialvelocityisVtrxVrt¼ðqpC0qÞD2pV2t18lrð4ÞTheflowintheclassificationzoneformsasemifreevortextypeflow.Vtrn¼constð5ÞHowever,thevortexcoefficientnwasabout0.8fromtheexperiment.Therefore,thefollowingrelationcanbeobtainedatthelouverontheradiusR.Vtrn¼ðVicoshiÞRnð6ÞFig.4.Flowvisualizationbytuftgridmethod.H.Morimoto,T.Shakouchi/PowderTechnology131200371–7974
编号:201311171525346814    大小:684.26KB    格式:PDF    上传时间:2013-11-17
  【编辑】
5
关 键 词:
教育专区 外文翻译 精品文档 外文翻译
温馨提示:
1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
  人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
0条评论

还可以输入200字符

暂无评论,赶快抢占沙发吧。

当前资源信息

4.0
 
(2人评价)
浏览:48次
英文资料库上传于2013-11-17

官方联系方式

客服手机:13961746681   
2:不支持迅雷下载,请使用浏览器下载   
3:不支持QQ浏览器下载,请用其他浏览器   
4:下载后的文档和图纸-无水印   
5:文档经过压缩,下载后原文更清晰   

相关资源

相关资源

相关搜索

教育专区   外文翻译   精品文档   外文翻译  
关于我们 - 网站声明 - 网站地图 - 友情链接 - 网站客服客服 - 联系我们
copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5