文献翻译-反应釜用机械密封设计.doc

文献翻译-反应釜用机械密封设计.doc

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南华大学机械工程学院毕业设计（论文）

附录

原文：

MechanicalSealDesignReactor

InstituteofElectricalandMechanicalDepartmentofGeneralChen

I.Introduction

Agitatedreactorischemical,pharmaceuticalproductioninoneofthekeyequipment,itsoperatingefficiencyandreliabilityofthedevicedependslargelyonthemeritsofparticularsealhigh-pressurehigh-temperaturereactorshaftsealiscurrentlytheneedforspecializedsolutionsproblem.

Chinahasbeensettingthestandardkettle-typemechanicalsealproducts,201,202,203,204,205,206,theuseofpressure1~16kgf/cm,shaftdiameteris30~ll0mm.Inrecentyears,withthepetrochemical,pharmaceuticalindustry,stirredtankreactorreactionpressure,temperaturegraduallyelevated,andthedirectiontowardsthedevelopmentofhighperformance.Pollutionpreventionandsafetyfromboth,energyconservationpointofviewofthesealdevicereliability,longevity,leakage

Quantityandeconomyandotherrequirementsarealsoincreasing.Therefore,theexistingstandardkettlewithmechanicalsealscannotfullymeettheirrequirements,uptotheneedtousespeciallydesignedworkingconditions.Inthispaper,ahightemperatureautoclavedesignofmechanicalsealforabriefintroduction.

Second,theconditionsgivenbytheuser

Device:

300literverticalreactor,stirringshaftinsertedfromthetop,single-bearing;

Maximumworkingpressure;25kgf/cm;

Temperature:

roomtemperature~15O℃

Stirringspeed:

12O~150rpm;

Medium:

diluteammonia+dehydroacetatepowder+solventBiochemistry;

Shaftdiameter:

30mm,diameterlengthratio:

1:

50;

Axialspace:

Kamaguchicouplingflangetothebacksidewhiletheheightisabout293mm;

Operation:

Intermittentoperation,stoppingfrequentlytoopen;

Leakage:

<3ml/h;

Life:

≥8000h（oneyear）.

Third,technicalanalysisanddesign

Accordingtotheconditionsandrequirementsofagivenpointofview,themechanicalsealisaveryharshoperatingconditions.Themainproblemsinvolved:

1.Toploadingautoclavetechnicalproblemswiththenatureofthemechanicalsealpumpmechanicalsealcompletelydifferent,becauseitisinthevaporspace（onlythematerialisliquidwhenthetankisfull）,sealproneto"dryrun."

2.Asthemediumisthechemicalreactionwithinthereactor,pressure,temperature,materialandshapechangearealwaysasked,inthestresscycleandtheroleofthermalcycles,thesealfacesdeformeasily.

3.Mechanicalsealusedatroomtemperature,duetothefrictionsurfaceoftheheatingandsealingofthemixingheatwillsealtheroomtemperaturerise.Whenusedathightemperatures,duetoheatconductionwithinthetank,thetemperaturewillfurtherrise,causingfrictionsurfaceoftheliquidfilmevaporation,resultingin"dryrun",andtopromotecorrosion,acceleratedagingauxiliaryring,resultingindeteriorationintheshorttermsealingperformance.

4.Stirringshaftinsertedfromthetopverticalreactor,itsdiameterlongerthanlarge.Itisasinglesupport,theamountofitsinevitableswinghigher.

5.Inthereactionprocess,themixerbladesandfluidmaterialgeneratedbyrelativemotionbetweenthevortex,mustbecausedbymixingshaftvibration.

6.Mayalsooccurforthefollowingreasonsaxistraverse:

（1）unevenorliquidfeedistoolow;

（2）formationdidnotcontrolthereactants,viscosityincreases;

（3）suddenchangesinspeedmixer;

（4）thermalexpansionorpressureandtemperaturefluctuate.

7.Becausethetopofthereactorveryeasytoinstallseal.Kettlemechanicalsealinthestructuremustbeeasytoinstallandremoval.Inthepast,mechanicalsealfailureresultinginperformance,manyofthemarecausedbypoorinstallationofthereactorbecausetheexistingpartsofmechanicalsealtothereactorneedtoinstallonebyone,weshouldensurethatitsaccuracyisdifficult.Accordingtotheconditionsgivenbytheuserandthetechnicalanalysistodeterminethefollowingbasicdesign:

1.Higheruseofsafetybarrierdoubleendmechanicalseal,toensurethereactorsealed.

2.Sealedfromtheoutsidetoenterthecleanroomsuitableforthelubricationofcoolingliquidresistancesealed,andsetthecoolingwaterjacket,toimprovethesealingoftheoperatingconditions

3.Thestructureofthesealingdevice,additionalbearingstoreduceshaftdeflectionandarockyledge.

4.Considertheeaseofinstallationandremoval,andeconomicfactors.

4,structuraldesignfeatures

Accordingtothedesignofmechanicalsealdesign,thefrictionpairmaterialforthesurfacingalloycarbon

Graphite,supportingringmaterial:

NBRa4O.

Specifictechnicalmeasures;

1.Considerthepressurefluctuationsinthedesignofthesealby30kgf/cm.Sidesealingsurfaceoftheupperatmosphericpressuretobearlarge,sodesignedasbalanced,30%,staticmethodsupportsdual-ringseal0-ringtoreducethestaticpartofthedeformation.Mediumwithinthelowerpartofthelateralsideofthesealingsurfacepressureissmall,itisdesignedtobenon-balanced.Itisworthnotingthatthissideofthesealmayseemeasy,infact,not.Ifnothandledproperlycauseleaks,pollutionvesselwillbewithinthematerial,resultinginproductfailure,wemustgiveourfullattention.Understaticcompressionringdoesnotusethetraditionalstructure,butwithgooduseofthefollowingfloating-mountedsothattheendisalwaysthebestfittomaintainthestate.

2.Installationofashorteraxialdimensionstructure,becausethesealandspringseatsharingadrive.Withasleeveonthekeywayandfixingscrewtodrivethedriveseat,sturdyandreliable

3.Thestructureofthesealbearingaddedtoimprovethedynamicstabilityofthemixingshaft（measuredatthetankflangerunoutoftheshaft0.05mm）.Mechanicalsealfromthebearingmountedclosetotheplace,thusenhancingthesealingoperationstability.

4.Officesinthesealedchambercoolingwaterjackettoreduceheatfromthereactorbodytopasschamber.

5.Introducedtothesealedchamberfromanexternalsealingliquid,onthemechanicalseallubrication,coolingandblockletters.

6.Thesealstructurehasafastandaccurateinstallationandremovalofbenefits.Thesealasanintegratedwhole,canbepre-assembled,andtested,andthenloadedontothekettle,donotneedtore-adjust.Ifthesealfails,theentiresealcanberemoved,thepre-assembly,debuggingcanbeagoodbackupsealfitted.Therefore,theinstallation,maintenanceandreplacementisveryconvenient,stoppingatthesametimegreatlyreducingthetime,withobviouseconomic

Benefits.

5,sealingliquidsystem

Forthereactorwithdoublemechanicalseal,thesealingperformanceandstabilitytomakelongworkinglife,thekeyistousepropersealingliquidsystem.Onthebasicrequirementsofsealingliquidsystemistoensurethesafeoperationofseal,namely:

1.Underacertainpressure,tosendthesealonthesealingliquidtomaintaintheliquidfilmbetweenthefrictionsurfaceandformabarrierbetweenthematerialandtheatmospheretoensurethatmaterialsnotleakfluid.

2.Closedloopliquidcirculationshouldbesufficienttotakeawaytheheatgeneratedbyfrictionsurfaceandbystirringshaftorcontainertoavoidtheconductionofheattothesealingdevice.

3.EnsurethattheKettleisalwaysinproperoperatingcondition.Thedesignofthesealingliquidpressurecontrolsystemusesbothmethods,thatis,thetoppickoutofakettlebody1-inchpipelinetoapressuretanktop.Pressuretankinstalledinthesealedroomabovethe2mDepartment.Sealingliquidsealchamberexitatthehighestpointofthewaterjacket,thermalsiphoneffecttoachievethepurposeofthecoolingcycle.Thevolumeofpressuretank2Oliters,madeofstainlesssteel.Theperipheralcoolingjacket,heattransferareaof0.02squaremeters,topreventthesealingliquidtemperatureoxidationanddeterioration.Pressuretanktothehighestpressure30kgf/c㎡.Setobituary.Attachmentsareusedinpressuregauge,liquidlevelmeter,andthermometers,exhaustvalveanddrainvalve,liquidfillingthemouthandsoon.Sealingliquidwithdiluteglycerol（glycerin,andsoftwaterof50%）,onceeverythreemonthstoreplace.Becausethesystemusesthermalsiphonmethod,asimpleeconomy,thepressurechangesinsidethereactortofollow,andcanensurethatthesealfluidpressurewithinthepressureslightlyhigherthanthekettle.

VIConclusion

Chemical,pharmaceuticalproductioninstirredtankreactor,theleakagedemanding.Ifexcessiveleakagewillresultinproductfailureorshutdown,sotheneedforeffectiveandreliablesealdevice.Practiceshowsthatthemechanicalsealtomeettheirrequirements.ThisarticledescribesthereactionvesselwithamechanicalsealforachemicalplantinAnhuidesign.Sincetheon-siteinstallationofthesealafterthesealingperformanceandstability,leakageisextremelysmall,lifenearlytwoyears,stillcontinuetouse.

反应釜用机械密封设计

机电部通用机械研究所陈德才

一、前言

搅拌式反应釜是化工、制药生产中的关键设备之一，其运行效率和可靠性很大程度上取决于轴封装置的优劣尤其是高压高温反应釜的轴封是当前需要专门解决的问题。

国内已定型的标准型釜用机械密封产品有201、202、203、204，205、206型，其使用压力为1~16kgf／cm，轴径为30～ll0mm。

近年来，随着石化、制药工业的发展，搅拌反应釜的反应压力、温度随之增高，并向着高性能方向发展。

同时从防止污染以及安全、节能等角度出发，对轴封装置的可靠性、寿命、泄漏量和经济性等方面的要求也越来越高。

因此，现有的标准型釜用机械密封产品已不能完全满足其要求，达就需要根据使用工况进行专门设计。

本文就一种高温高压反应釜用机械密封的设计作一概要的介绍。

二、用户给定条件

装置：

300立升立式反应釜，搅拌轴从顶部插人，单支承；

最高工作压力；25kgf／cm；

温度：

室温～15O℃

搅拌速度：

12O～150rpm;

介质：

稀氨水+脱氢醋酸粉料+生物化学溶剂；

轴径：

30mm，径长比：

1：

50；

轴向空间:

釜口法兰至联轴节背端而高度约为293mm;

操作方式：

间歇操作，开停频繁;

泄漏量:

<3ml／h;

寿命:

≥8000h（一年）。

三、技术分析和设计思想

根据给定的条件和要求来看，该机械密封的运转条件是相当恶劣的。

所涉及的主要问题是:

1．顶装釜用机械密封的技术问题性质完全不同于泵用机械密封，因为它是处于气相空间中（只有物料为满釜时才是液相），密封易出现“干运转”。

2．由于介质是在釜内进行化学反应，压力、温度、物料的形态等都是随时问而变化的，