文献翻译-精馏塔的故障诊断γ射线扫描技术

英文论文翻译英文原文：TroubleshootingDistillationColumnbyGammaRayScanningTechniqueBaoXiaojun,WeiWeishen,LiuYansheng,ShiGangandShenFuThekeylaboratoryofcatalysis,Chinanationalpetroleumco.,universityofpetroleum,Beijing102200,China【Abstract】Adigitallycontrolledthree-dimensionalgamma-scanningapparatuswasdevelopedandusedtotroubleshootdistillationcolumninthepresentinvestigation.Ina140mm(ID)modelcolumn,variousmalfunctionphenomena,bothrateandprocessrelatedconditionsandstructuralproblems,whichwaybefrequentlyencounteredintheoperationoftrayandcolumns,wereexperimentallysimulatedandtestedwiththedevelopedscanningsystem.Theexperimentalresultsshowedthatthescanningspectracanfairlyreflectthesimulatedphenomena.Thesalientfeatureofthescanningapparatusliesinthatitintegratesthesocalledgridscanandcomputer-assistedtomographyscaninasinglesystem.Itwasconfirmedthatthegamma-scanningtechniquecanserveasanimportanton-linetroubleshootingandmaintenancetool.【Keywords】gammarayscanning,distillation,troubleshooting1.IntroductionIthasbeenwidelyacceptedthatgamma-scanningorradiationscanningcanplayakeyroleintroubleshooting,predictivemaintenanceandoptimizationofdistillationcolumns,althoughitsapplicationhasbeenexpandedtootherchemicalengineeringequipmentnow.Itwasnotedthatgamma-scanningprovidesessentialdatato(1)optimizetheperformanceofcolumns(andothervessels);(2)extendcolumnruntime;(3)tracktheperformance-deterioratingeffectsoffoulingandsolidsdeposition;and(4)identifymaintenancerequirementswellinadvanceofscheduledturnarounds.Baoetal.showedthatwithelaboratelydesignedscanningapparatusthequantitativeinformationaboutthehydrodynamicbehaviorinbothtrayandpackingdistillationcolumnsandthesoliddistributionandcokedepositioninthefluidcatalyticcracking(FCC)unitcouldbeobtained.Thesuccessoftheseapplicationsdemandsabetterdesignofthescanningsysteminordertoobtainmoredetaileddescriptionoftheprocesstobeevaluated.Therearethreetechniquesthatuseradioisotopes,i.e.,gridscanning,tracing,andcomputer-assistedtomography(CAT)scanning.TheirapplicationareasandfeatureshadbeensummarizedbyBowman.Inthepresentcontribution,athreedimensionaldigitallycontrolledscanningapparatusthatintegratesgridscanningandCATscanninginasinglesystemwasdevelopedandusedforthedetaileddescriptionofmalfunctionofdistillationsandstructuralproblems.Inadditiontothedescriptionofthescanningapparatus,variousspectraofdensity/countvs.positionprofilesandcorrespondingmalfunctionperformanceswerepresentedanddiscussed.2.ScanningapparatusFortroubleshootingscan,aradiationsource(Cs137,40mCi)andaNaIscintillationdetectorarealignedontheoppositesidesofacolumnorvessel.Theyarethensynchronouslyelevatedwhileintensityvs.heightprofilesarelogged.Theprocesschangeinthecolumnduetoitsgeometricalstructureandtheflowingmediainsideitcanbedistinguishedbycomparingtheemptyscanatreducedloadingswithanactualtroubleshootingscan.ThesimplescanningapparatusintroducedbyD.W.JonesandJ.B.Jonescanbefairlyappliedforthispurpose.Forfineprocessdescriptionsuchasthedeterminationofthethree-dimensionalgas-soliddensitydistributioninaFCCunit,however,asophisticateddesignisdemanded.Inthepresentinvestigation,apatentedthree-dimensionalscanningapparatuswasconstructedbyimplementingarotaryplatformtotheone-dimensionalscanningapparatuspreviouslydevelopedtoperformrotaryandhorizontalscanmotion.Thiscombinationmakesthree-dimensionalscanpossible.Thedetailedconfigurationofthe3-Dscanningsystemandcontrollingandloggingsystemcanbereferredtothetwopatentapplicationscitedabove.3.Applicationtodistillationcolumn3.1ApplicationtotraycolumnUsingtheone-dimensionalscanningapparatuspreviouslydeveloped,variousmalfunctionalphenomenasuchascompletetrayfalling,partialdamage,trayholeplugging,floodingetc.areinvestigated.ThetypicalresultsareillustratedinFigs.1,2and3.Fig.1showsanemptyscanforanewtraycolumnof140mmafterinstallation.Itcanbeseenthatthepeaksinthedensityprofileareapproximatelysamewiththesametrayplategeometry.Fig.2showsascanwiththefirsttrayremoved,thethirdpluggedwithhalfoftheholes,andthefourthdrilledwith2largerectangularholes.ItcanbeeasilyconcludedthatthepeakattheplacewherethefirsttrayplatewasoriginallyinstalledismuchlowerthanthatinFig.1,thepeakofthetray3islittlehigherthanthatinFig.2,andpeakofplate4standsbetweenthoseofthetrays2and3.WhenthecolumndescribedbyFig.2wasoperatedwithgas(air)andliquid(water)phasesundernormalconditions,thescanresultisillustratedinFig.3.Itcanbeseenthatnofrothexistsonthefirsttrayandthefourthtraybecauseofcompletefalling-offofthefirsttrayandseriousdamageofthefourthtray,andtheapproachofthefrothonthethirdtraytothesecondtrayindicatesobviousflooding.Italsorevealsthatthefrothheightonthesecondtrayisabout160mmandthenormaloperationholds.Inadditiontotheresultsstatedabove,aseriesofexperimentsnotquotedherewereconductedtoidentifyothermalfunctionalphenomenasuchaslocalflooding,excessiveentrainmentandweepingwhicharenotsoobviousasthosementionedaboveandtoquantifythehydrodynamiccharacteristicsuchastheflowregimetransition,clearliquidheight,frothheight,crestliquidheightoverexitweir,downcomerhydraulicsandsooninthetraycolumn,andsatisfactoryresultswereobtained.3.2ApplicationtopackedcolumnForthepacked-columnapplication,agridscanisessentiallyrequired.Thegridscanshouldbeperformedundermorepreciselycontrolledconditions.Forapackedcolumn,ascanwithatleast2pairsofparallelscanlineswhichcrossinthewayasillustratedbyFig.4isneeded.Eachofthefourscanlineorientationsareequaldistancefromsourcetodetector(equidistantchords)andeachpairofparallelscanlinestraddlethecenterlineatequaldistance.Byanalyzing4density/countprofilesobtained,therateandprocessrelatedmalfunctionalconditions(suchasentrainment,weeping,foaming,foulingorpluggingofpackedbedandexcessivelyheavyorlightloadingduetooperatingcondition)andmechanicalproblems(suchascrushed,settled,corrodedordisplacedpacking,damagedorpluggeddistributorsandcollapsedpackedbeds)oracombinationofbothcanbefairlyidentifiedandlocated.Bytheapparatusdevelopedinthecurrentinvestigation,aseriesof22gridscanswereconductedinthelaboratoryscalePlexiglaspackedcolumnofID140mmandwallthickness5mmoperatedwithairandwater.Thepackedbedconsistsofthreeparts,i.e.,thestructuredpackingsmadeofstainlesssteelintheloweranduppersection,andthe-ringpackingsmadeofstainlesssteelinthemiddlesection.Onthetopofthecolumnisacross-typeliquiddistributor.Betweentheupperstructuredpackingandthedistributorthereisavaporspace.TheemptyscanisillustratedinFig.5.CurvesfromsourceAandCinthefigurestandhigherthancurvesfromBandD.WhentheliquidwasfedintocolumnattheplaceclosetothecolumnwallwherescanlinesAandCcrossbyinsertingtheinlettubedirectlytothepackedbedinsteadoffeedingthroughthedistributor,thescanisshowninFig.6.LookingatthecurvesAandCinthefigure,itisclearthattheyshowamuchmoredistinctdecreasethancurvesBandD,indicatingchannelinginthecolumn.Thefourcurvespreviouslyscatteredapartnowapproachtoeachothersoclosethattheyaredifficulttobedistinguished.Whenthebedcollapses，somepartofthebedwillbecomedenselypackedandsomeloosely,andevencavitiesmayexist.Thissituationwassimulatedexperimentallybyreplacingsome-ringswithanironblockandsomewoodballs.ThescanforthiscaseisgiveninFig.7.Itisapparentthatthedatacorrespondingtotheplacewheretheironblockwaslowerincounts,ormoredense,whereasthedataintheplacewherethepackingwerereplacedbywoodballsshowonlyslightlyincreaseincounts.Inthiscase,thescandatashouldbeanalyzedwithcaution.Fig.8showsascanforthewell-packedcolumnoperatingunderfloodingcondition.Becausefloodingprevailsinthewholecolumn,allofthefourscancurvesdemonstrateastrongdecreaseincountsduetoliquidaccumulation,especiallyinthevaporspaceinthecolumn.4.ConclusionsAdigitallycontrolledthree-dimensionalgamma-scanningsystemwasdevelopedonthebasisoftheone-dimensionalscanningapparatuspreviouslydesignedandusedforthefinedescriptionofthemalfunctionalphenomenainbothtrayandpackeddistillationcolumns.Theexperimentalresultsshowthatboththerateandprocessrelatedconditionsandmechanicalproblemscanbefairlyidentifiedbythetechniquedevelopedinthepresentinvestigationandthisshouldlayaprospectivebasisfortheapplicationofradiationscanningtopredictivemaintenanceandoptimizationofdistillationcolumninadditiontoitstroubleshootinguse.TheveryrecentapplicationofthisscanningsystemtoindustrialequipmentsuchasFCCfractionator,sulfur-containingwastewaterstrippercolumnandstandingpiperinFCCunitbytheauthorsdemonstratedthatvariousmalfunctionalphenomenacouldbeaccuratelydetectedbythetechnique.ACKNOWLEDGEMENTSTheauthorswishtothankProfessorChenJiayongoftheInstituteofProcessesEngineering(formerlyInstituteofChemicalMetallurgy),ChineseAcademyofSciencesforhisconstantconcernsandvaluableadvicesonthecurrentandmanyotherresearchprojects.REFERENCES1.Bowman,J.D.，“Troubleshoottowerswithradioisotopes”,Chem.Eng.,89(9),34-41(1993).2.Bao,X.J.,He,K.A.,Liu,Y.S.,Shen,F.,“Insightintodistillation/absorptioncolumnsandFCCrisersusinggammascanningtechniques”,ChineseJ.Chem.Eng.,3(3),171-179(1995).3.Bowman,J.D.,“Usecolumnscanningforpredictivemaintenance”,Chem.Eng.Prog.,87(2),25-31(1991).4.Jones,D.W.,Jones,J.B.,”Traysperformanceevaluating”,Chem.Eng.Prog.,71(6),65-72(1957).5.Bao,X.J.,Yan,X.F.,Wei,W.S.,Zhou,L.C.,Shi,G.,Xiao,L.X.,Liu,Y.S.,“Anelevatingscanningapparatusforcolumn-typeequipmenttroubleshooting”,ChinesePatentApplication,01115892.1,May14(2001).(inChinese)6.Wei,W.S.,Bao,X.J.,“Agammarayscanningdensitometer”,ChinesePatentApplication,01115891.3,May14(2001).(inChinese)7.Feng,R.J.,Huang,Z.X.,Xu,X.M.,Shen,F.,“Anumericalcontrolscanninggammarayattenuationtechniquefortheinvestigationoftwophasefluidcharacteristicsondistillationtrays”,J.Chem.Ind.Eng.(China),40(3),379-382(1989).(inChinese)8.Yan,X.F.,Wei,W.S.,Bao,X.J.,“Developmentofgamma-rayscanningtechniqueforcolumnfailurediagnosis”,PetroleumRefineryEngineering(China),30(8),24-27(2000).(inChinese)9.Yan,X.F.,Li,Z.Q.,Zhou,L.G.,Xiao,L.X.,Wei,W.S.,Bao,X.J.,“Troubleinspectionincolumnbygamma-rayscanning”,PetrochemicalTechnology(China),8(1),39-41(2001).(inChinese)译文精馏塔的故障诊断射线扫描技术鲍晓军，魏伟胜，刘艳升，石冈，沈复重点实验室的催化中国国家石油公司，中国石油大学，北京102200【摘要】在目前的调查中，一种数控三维射线扫描仪已经被发展和用来检修精馏塔故障，在140毫米（直径）塔中，各种故障现象，在塔盘和塔的操作常常地遇到无论速度和进程的相关条件和结构性问题，解决这些问题的方法是用发达扫描系统实验模拟和测试。实验结果表明，扫描光谱可以完美地反映模拟现象。扫描仪器的显着特点在于它集成了所谓的网格扫描和电脑辅助断层扫描在一个系统中。据确认，-扫描技术可以作为一个重要的在线故障诊断和维护工具。【关键词】射线扫描；蒸馏；故障诊断。1.简介伽玛扫描或辐射扫描被广泛地认为在查明故障、有预测性的分裂蒸馏塔的维护和优化可能扮演一个关键角色，虽然它的应用现在被扩展了到其他化学工程设备。有人指出，伽马射线扫描提供基本数据来（1）优化性能的塔（及其他容器）;（2）延长塔运行时间;（3）跟踪业绩恶化的影响污染和固体沉积;和（4）确定维持相当一段时间内要求提前预定逆转。鲍晓军等人证明，利用那精心设计和制作的扫描仪，那些关于流体力学行为的定量信息在塔盘和包装的分裂蒸馏塔和在坚实分布和焦炭可变的催化裂化(FCC)单位可能获得。这些应用的成功，需要一个更好的设计的扫描系统，以获得更详细的说明的过程进行评估。这里有三种技术，即使用放射性同位素，网格扫描、追踪，和电脑辅助断层扫描（CAT）。他们的这些应用领域和功能已经被鲍曼概括过。在目前的实践中，三维数字控制扫描仪，一种集成网格扫描和CAT扫描在一个单一的系统开发和使用的三维数控扫描仪已经被研发出来并应用来详细说明蒸馏中产生的故障和结构性问题。除了扫描仪的说明，并对各种谱密度/伯爵与立场概况和相应的故障表现进行了介绍和讨论。2.扫描用具为了查明故障扫瞄，一个辐射源(Cs137,40mCi)和NaI闪烁探测器被排列在塔或容器的反面。当强度对高度外形被采伐时，他们同步然后被举起。在这个过程中，塔内部的变化它的几何结构和它内部的流动介质可以通过在减少的装货的空的扫瞄区别与实际查明故障扫瞄比较。这种由D.W.琼斯和J.B.琼斯介绍的简单的扫描用具最后可以为此而投入使用。精细过程的描述，如确定三维气固密度分布在催化裂化装置中，却要有老练的设计要求。在当前调查中，获得专利的三维扫描仪实际上是通过对以前被发展的一维扫描仪的一个转台式平台修建进行转台式和水平的扫瞄行动。这个组合使三维扫瞄成为可能。三维扫描系统和控制和记录系统的详细的配置可以提到被援引的二个专利申请以上。3.在分裂蒸馏塔的应用3.1在塔盘的应用使用以前开发了的一维扫描用仪，能调查各种各样的例如塔盘完全下跌的，部份损伤，塔盘孔塞住，充斥等故障现象。这些典型的结果在图1，2和3中展示出来了。图1显示了一个新的直径140毫米的塔盘安装后的空扫描。显然在密度剖面图里的顶峰是大约有相同的塔盘几何学的同一事物。图2显示除去第一个塔盘的一次扫描，第三个的洞的一半被堵塞，并且第四个有两个大的矩形的洞。这可以容易地看出第一块塔盘板材最初安装的地方的顶峰低于图1中的位置，塔盘3的峰顶稍高于图2中的，而峰顶板材4在塔盘2和3之间。当图2描述的塔是通常情况下气体(空气)和液体(水)阶段，扫描结果在图3中被证实了。