机械密封基础知识(二)

2006新进员工技术培训资料之三,机械密封基础知识（二）,主要内容,JohnCrane机械密封产品介绍机械密封辅助系统介绍,机械密封的布置方式单端面密封,Single单密封InsideMounted内装式,单端面密封布置方式SingleSealArrangements,ProcessFluid工艺流体,Shaft轴,Atmosphere大气,Single单密封OutsideMounted外装式,单端面密封布置方式SingleSealArrangements,ProcessFluid工艺流体,Shaft轴,Atmosphere大气,InsideMounted内部安装,MatingRing非补偿环,Atmosphere大气,Shaft轴,GlandPlate压盖,PumpHousing泵腔,SealHead密封头,ProcessFluid工艺流体,SealHead密封头,ProcessFluid工艺流体,OutsideMounted外部安装,PumpHousing泵腔,Atmosphere大气,GlandPlate压盖,Shaft轴,MatingRing非补偿环,单端面密封布置方式SingleSealArrangements,RotatingHead&RotatingSeat旋转头和旋转座,UseRotatingHeadAssembliesupto:3500fpmforSingleSpringDesigns5000fpmforMultipleSpringDesigns,SealHead,Seat,Rotating,RotatingHead旋转头,SealHead,Seat,Rotating,RotatingSeat旋转座,Stationary,Stationary,Advantages优点LessRadial&AxialSpaceRequirements需要的径向和轴向空间小LowerCost成本更低,Advantages优点HigherSpeedCapability更高的转速ToleratesMisalignmentBetter对中精度要求不高BetterCooling更好的冷却性能,单端面密封布置方式SingleSealArrangements,机械密封的布置方式多级密封,一个单端面密封是不够的,Singlesealsutiliseprocessfluidtoprovidethelubricatinginterfacefilm单端面密封通常采用介质润滑密封面,Usemultiplesealsif:fluidistoxic介质有毒fluidisflammable易燃environmental污染环境isolationrequired不允许泄漏fluidchangesstate介质发生相变fluidisnotagoodlubricantorisagas介质润滑性差或是气体fluidisunstable介质不稳定dryrunninglikely可能干运转expensiveproduct介质昂贵criticalpump重要的泵,串联密封MultipleSeals:Tandem,Basictandemnon-pressuriseddouble,Productlubricatesthisseal靠介质润滑,Thissealisunderfullproductpressure承受全部压力,InboardSeal内侧密封,Notepossiblecontaminationofbarrierfluid注意介质可能污染密封液,UseAPIPlan52,串联密封MultipleSeals:Tandem,Cleanbarrierfluidlubricatesthisseal靠洁净的密封液润滑,OutboardSeal外侧密封,Barrierfluidisatlow(atmospheric)pressure.密封液压力比较低,UseAPIPlan52,Basictandemnon-pressuriseddouble,串联密封MultipleSeals:Tandem,Inboardsealmostlikelytofailfirst一般内侧密封先失效,Barrierfluidlevel/pressurewillrise密封液压力升高,Processcancontinueuntilcompleted密封仍然可以维持一段时间,UseAPIPlan52,Basictandemnon-pressuriseddouble,多级密封：背对背MultipleSeals:DoubleBack-to-Back,Basicback-to-backpressuriseddoubleseal,UseAPIPlan53,Iftheoutboardsealfails,thebarrierpressurewillfailandpumpmustbeswitchedoffasproductwillleakout如果外侧密封失效，无法维持密封液压力，泵必须停止使用,UseAPIPlan53,Basicback-to-backpressuriseddoubleseal,多级密封：背对背MultipleSeals:DoubleBack-to-Back,Similarinoperationtoback-to-backdoubleseal与背靠背双端面密封类似Muchshorterarrangement-onlyoneseat轴向尺寸更短只有一个动环Simplerotatingcomponents旋转组件结构简单,多级密封：面对面MultipleSeals:DoubleFace-to-Face,辅助密封,辅助密封SecondaryContainment,Leakagedirectlytoatmosphere,辅助密封SecondaryContainment,Requiredto:containhazardousemissions防止泄漏containproductleakagewhenmainmechanicalsealfinallyfails当主密封失效时防止介质泄漏isolateproductfromtheatmosphere隔离介质和大气Coking结焦Crystallising结晶Freezing凝固Polymerising聚合containaquenchforotherreasons(e.g.cooling)冷却、冲洗,辅助密封SecondaryContainment,急冷与冲洗QuenchandFlush,Quench急冷lowpressure(0.5barg)压力低lowflow(0.5litres/minute)流量低externaltomainseal从外部引入nocontamination对介质无污染nodilution没有稀释作用Flush冲洗highpressure(1.0barabovesealpressure)压力高injectedintosealchamber注入密封腔coolspumpedproduct冷却介质dilutespumpedproduct对介质有稀释作用,辅助密封碳环SecondaryContainmentBushings,Non-contacting非接触Fixednon-sparkingthrottlebush固定安装，防火花衬套MinimumrequirementforAPI610满足API610最低要求Leakagereduction较少泄漏量Anyshaftmovementwillcausewear轴的任何位移都将导致磨损,UseAPIPlan61,Non-contacting非接触Floatingcarbonbush浮动碳环MinimumrequirementforAPI682满足API682的最低要求Moveswiththeshaft与轴一起移动Leakagereduction较少泄漏量Steamquench蒸汽急冷Lesswear减少磨损Longerlife寿命长,UseAPIPlan61,辅助密封碳环SecondaryContainmentBushings,Non-contacting(close)非接触Floatingcarbonbush浮动碳环Oftensegmentedforeaseofreplacement分瓣MinimumrequirementforAPI682满足API682最低要求Moveswiththeshaft与轴一起移动Leakagereduction泄漏量减少Steamquench蒸汽急冷Lessleakage泄漏量更少Longerlife寿命更长,UseAPIPlan61,辅助密封碳环SecondaryContainmentBushings,ContactingorNon-contactingMaterialstosuitNon-contactingactslikeplainbushcanbecompressedwhensealleaks,辅助密封碳环SecondaryContainmentBushings,ContactingorNon-contactingMaterialstosuitNon-contactingactslikeplainbushcanbecompressedwhensealleaks,Contactingmustsupplycontinuousquench,UseAPIPlan62or51,辅助密封碳环SecondaryContainmentBushings,Contacting接触型VariouslipsealtypedevicesIsolateproductfromatmosphereandcontainanyleakageMustsupplylubricantatalltimes(quench)必须有润滑Lowpressuresonly只能用于低压,UseAPIPlan62or51,辅助密封唇封SecondaryContainmentLipSeals,Contacting接触型Lipsealreversed唇封反装Idealforgreaselubrication最好用脂润滑Actsassafetyvalve作为安全密封Usedinpaperandsugarindustries用于造纸和制糖业,UseAPIPlan62or51,辅助密封唇封SecondaryContainmentLipSeals,约翰克兰机械密封产品介绍,约翰克兰机械密封产品介绍,FamilyA非推进型橡胶波纹管机械密封特点：自动平衡型，不易阻塞；具有缓冲补偿和密封的双重功能具有较高内阻，可同时承受多向载荷不考虑旋向，安装拆卸简单方便批量生产，价格便宜基本密封型号：Type1,1A,1B,1100Type2,2B,502,521Type6A推荐型号：Type2100,约翰克兰机械密封产品介绍,FamilyB：推进型“O”型圈二次密封机械密封特点：结构简单，二次密封为“O”型柔性件结构便于安装与维修不损伤轴(轴套)表面双旋向结构设计具有非平衡，平衡型两种设计选用不同材料应用范围广泛经改型设计，广泛应用于烃泵易挥发介质基本密封型号：Type58U,58B,8-1,8B1,48,5610,5620Type1648,2648,3648(符合API682标准),约翰克兰机械密封产品介绍,FamilyC：非推进型PTFE波纹管机械密封特点：外装PTFE波纹管设计应用于强腐蚀介质工况具有波纹管密封结构的特点使用温度-45CTo120C压力UpTo13bar速度UpTo16m/s基本密封型号：Type10TType10R,约翰克兰机械密封产品介绍,FamilyD推进型PTFE楔型机械密封特点：结构简单-二次密封为楔型环标准设计，尺寸和基本传动件与8型互换具有非平衡型和平衡型设计密封材料应用广泛特别适合石油，化工和医药行业特别适合于硫酸，硝酸，磷酸，盐酸，氢氟酸等介质工况基本密封型号：Type59U,59BType9,9B,9T,9BT,109,109B,约翰克兰机械密封产品介绍,FamilyE非推进型挤压成型金属波纹管机械密封特点：具有波纹管密封的优点挤压成型易于冲洗适合含纤等浆液Flexibox双复合层金属波纹管增加30%的轴向韧性，极大增加弹性压缩量由于不存在径向焊缝，几乎不存在多焊缝的热影响区基本密封型号：Type515E,515CTypeGL1B,GT1B,RT1B,约翰克兰机械密封产品介绍,FamilyF非推进型焊接金属波纹管机械密封特点：具有波纹管密封无阻塞的优点固有的平衡型设计，结构紧凑SEALOL双波450倾角波片设计分散应力波纹管可补偿动环磨损，安装误差，波片自动清洗功能设备精度和温度的变化零部件少于推进型密封多种材料组合适合于不同工况JohnCraneSealol基本密封型号：Type604,606,609Type670,680TypeEZ1TypeECS,约翰克兰机械密封产品介绍,FamilyG非接触气膜干气密封特点：气膜非接触，附加功率损失减少95%无磨损，事实上排除不定期维修由于使用惰性缓冲气工艺气零泄漏排除油系统，节约投资成本节省占地空间，排除密封油储运处理符合环保节能要求基本密封型号：压缩机用：Type28AT,28HP,28XP,28BD泵用：Type2800,2800E搅拌釜用：Type28MB,Type2800,PumpCasing(LargeBore),Type2800,Temperature:-40Cto+260CPressure:Fullvacuumto21bargSpeed:3m/sto25m/s,Type2800E,Faceslift,约翰克兰机械密封产品介绍,API682机械密封标准(第二版)机械密封石油化工泵制造商制造商工业主机厂API682的最终目的是可靠性,安全性,减少泄漏机械密封使用寿命最低为三年节能问题倍受关注,以寿命成本为考核依据满足最终用户的利益,机械密封辅助系统APIPipingPlan,机械密封辅助系统,机械密封辅助系统应用:基本系统-为保证机械密封正常使用,选用正确的密封辅助系统,增加如冲洗,循环,抗温,抗压,排渣,节流,润滑,防结晶,防介质泄漏等功能,改善机械密封的工作环境,从而保证机械密封的正常运行.基本系统功能:控制泄漏控制压力控制磨蚀控制腐蚀防污染防泄漏基本系统分类:API610PLAN系统介质冲洗API610PLAN01,11,12,13,14，21,22,23,31,41外流体冲洗API610PLAN32,51，（61）62缓冲液（气）循环系统API610PLAN52，72隔离液（气）循环系统API610PLAN53A,53B,53C,54，74收集与排放系统APIPLAN（71），75，76,Q/D,V,Q/D,HCI/HCO,V,Integralrecirculationfrompumpdischargetoseal,Dead-endedsealchamberwithnocirculationofflushedfluid.Water-cooledsealchamberjacketandthroatbushingrequiredwhenspecified.Note:Incertaincircumstances,itmaybenecessarytoremovethethroatbushingandboreboxthrough.,Plan02(CleanPumpage),Plan01(CleanPumpage),机械密封辅助系统,1,1,Integral(internal)recirculationfrompumpdischargetoseal内部循环从泵的出口到密封,Advantage优点-Noexternalpiping没有外部冲洗Limitations局限性-Changingflowraterequireddismantlingofpump改变流量需要拆泵-Forcleanpumpagesonly只能是适用干净的介质,机械密封辅助系统,F,Q/D,V,Q/D,F,V,Plan11(CleanPumpage),Plan12(CleanPumpage),Recirculationfrompumpcasethroughorificetoseal(By-passfromdischarge).,Recirculationfrompumpcasethroughstrainerandorificetoseal.Note:Strainersarenotnormallyrecommendedduetoblockagepossiblycausingsealfailure.JohnCranepreferredoptionisaPlan31.,机械密封辅助系统,2020/5/30,冲洗液从泵出口通过节流孔板到达机械密封可形成封闭循环,对于API11须注意:-如果泵出口压力比密封腔压力高3bar，用一节流孔板来限制流速-适用于干净和颗粒较少的情况下,机械密封辅助系统,Topumpsuction,V,F,Q/D,Q/D,F,V,Recirculationfromsealchamberthroughorificeandbacktopumpsuction.Note:Applicableprimarilyforverticalcan/turbinepumps.,Recirculationfrompumpcasethroughorificeandheatexchangertoseal.,Plan13(CleanPumpage),Plan21(CleanPumpage),机械密封辅助系统,2020/5/30,冲洗液从密封腔通过一节流孔板，再回到泵入口处，形成一封闭循环,对于Plan13须注意:-如果泵入口压力比密封腔压力低3bar，用一节流孔板来限制流速-用于有颗粒的情况，Plan13要优于Plan11-较高的密封腔压力可抑制它的汽化,机械密封辅助系统,TI,Q/D,F,V,Recirculationfrompumpcasethroughorificeandheatexchangertoseal.Note:Strainersarenotnormallyrecommendedduetoblockagepossiblycausingsealfailure.JohnCranepreferredoptionisaPlan41.,Plan21(CleanPumpage),机械密封辅助系统,冷水出口,冷水入口,机械密封辅助系统,RecirculationfromapumpingringinthesealchamberthroughcoolerandbacktosealClosedLoopCoolingCircuit冲洗液通过密封腔中的泵效环从密封腔中流出经过换热器，再返回到密封中，形成自封闭循环。形成封闭的冷却回路,Throatbushing,Suction入口,Discharge出口,18-24,Ventathighestpointofthepiping排起在管线的最高点,CoolingWaterOutlet冷水出口,CoolingWaterInlet冷水入口,mechanicalsealwithpumpingring,Heatexchanger换热器,机械密封辅助系统,Frompumpdischarge,Topumpsuction,Q/D,F,V,By,vendor,By,purchaser,TI,PI,Fromexternalsource,V,F,Q/D,Recirculationfrompumpcasethroughcycloneseparatordeliveringcleanfluidtosealandfluidwithsolidsbacktopumpsuction.,Plan31(Dirty/SpecialPumpage),Plan32(Dirty/SpecialPumpage),Injectiontosealfromexternalsourceofcleanfluid.Note:Careshouldbeexercisedinchoosingpropersourceinsystemtoeliminatevaporizationinthesealflush.,机械密封辅助系统,2020/5/30,冲洗液从泵出口流出，通过一旋液分离器，使干净流体进入密封腔，带有颗粒的流体返回到泵入口处形成封闭循环,机械密封辅助系统,2020/5/30,从外冲洗源将干净的冷却流体注入密封腔,对于APIplan32须注意:-选择合适的密封冲洗源，以减少冲洗流体的汽化，同时可避免冲洗流体被污染。-如有必要的话，在密封腔底部安装喉部衬套或迷宫密封来控制冲洗和压力。,机械密封辅助系统,ThroatBushing喉部衬套,Vent,Reservoir,Q/D,F,V,Frompumpdischarge,Topumpsuction,Q/D,F,V,Recirculationfrompumpcasethroughcycloneseparatordeliveringcleanfluidthroughheatexchangertosealandfluidwithsolidsbacktopumpsuction.,Dead-endedblankettypicallyusedwithauxiliarysealingdevice.,Plan41(Dirty/SpecialPumpage),Plan51,APIFlushPlans,机械密封辅助系统,Recirculationfrompumpdischargethroughacycloneseparatordeliveringcleanfluidthroughacoolerandthentosealandfluidwithsolidsbacktopumpsuctionline,CoolingWaterOutlet,CoolingWaterInlet,机械密封辅助系统,2020/5/30,针阀,外设容器提供端盖上吹扫口中的流体，相当于形成一个一端盲死的夹套,对于APIplan51须注意:-在密封大气侧，一端封闭的情况可防止潮气的冻结，这样在泵启动时，密封面就不会粘接在一起。典型应用工况：应用于泵在0C以下-API610第8版已取消该方案,机械密封辅助系统,Whenspecified,PS,PI,FI,Vent,Normallyopen,BI,BO,Reservoir,Reservoir,Vent,BO,BI,F,Plan52(Non-pressurizedBuffer),APIFlushPlans,Non-pressurizedexternalfluidreservoirwithforcedcirculationtypicallyusedwithatandemsealarrangement,机械密封辅助系统,压力表,液位计,球阀,节流孔板,Drain,液位开关(高),液位开关(低),压力开关,(一般置常开位置),放空阀,venttosafearea,机械密封辅助系统,PointstoNoteforAPIPlan52:TypicallyusedwithanArrangement2unpressuriseddualseal.通常用于不带压双封Duringnormaloperation,circulationismaintainedbyaninternalpumpingring.在正常操作情况下，通过腔内的泵效环维持循环Thereservoirisusuallycontinuouslyventedtoavapourrecoverysystemandismaintainedatapressurelessthanthepressureinthesealchamber.储罐通常与回收系统相连通，罐内压力通常低于密封腔压力,Externalreservoirprovidingbufferfluidfortheoutersealofanunpressuriseddualsealarrangement.外部储罐对不带压双封的外密封起缓冲液的作用,PressureGauge压力表,LevelGauge水准仪,LevelSwitch(L)电平开关,VentValve排气阀(NormallyClose)通常关着,Orifice,PressureSwitch压力操纵开关,ExternalPressure外部压力Source,One-wayBlockValve(NormallyOpen),PointstoNoteforAPIPlan53:TypicallyusedwithanArrangement3pressuriseddualseal.通常用于带压双封Duringnormaloperation,circulationismaintainedbyaninternalpumpingring.在正常操作情况下，通过腔内的泵效环维持循环Thereservoirpressureisgreaterthantheprocesspressurebeingsealed.罐内压力通常高于被密封介质压力,Externalreservoirprovidingpressurisedbarrierfluidfortheoutersealofanpressuriseddualsealarrangement.外部储罐对带压双封的外密封起隔离液的效果,Drain,机械密封辅助系统,PointstoNoteforAPIPlan54:TypicallyusedwithanArrangement3pressuriseddualseal.通常用于带压双封Duringnormaloperation,circulationismaintainedbyanexternalpumporpress