密封基础知识(基本结构)PPT课件

.,1,BasicMechanicalSeals密封基础知识,JCTianjinTraining,.,2,rotatingsealunit,twoflatslidingsurfaces,whichmaintainacloserunningclearancewhileseparatedbyafluidfilm两个光滑平面之间维持着一个由流体膜隔开的微小间隙,stationarysealunit,Whatisamechanicalseal?什么是机械密封？,.,DesiredFeaturesofaSeal机械密封必须有的特征,Long-life很长的寿命Easymaintenance容易检修Lowcost低成本,Smallaxialclearance小的轴向间隙Selfadjusting自调节,ShaftMovement轴的运动,.,4,BasicMechanicalSeal基础机械密封,Looseringsetscrewedtotheshaft把一个有间隙的环用顶丝固定在轴上,1,.,5,BasicMechanicalSeal基础机械密封,O-ringpreventsleakagethroughthebore,2,.,6,BasicMechanicalSeal基础机械密封,Springensuresautomaticadjustment弹簧确保自动调整,3,.,7,BasicMechanicalSeal基础机械密封,4,.,8,BasicMechanicalSeal基础机械密封,5,.,9,BasicMechanicalSeal基础机械密封,GasketorO-ring,SEAT,Recirculationforcooling,SPRINGORSPRINGFORCE,.,O-RingO型圈,Shaft轴,MatingRing配合环,PrimaryRing补偿环,SnapRing卡环,Anti-XRing挡环,O-RingO型圈,Disk推环,Springs弹簧,Retainer传动套,SetScrew定位螺丝,AnExampleofaCompleteSeal一个完整密封的例子,.,Simplyput,amechanicalsealis:简单的说,机械密封就是:,1.Awearable,stationary,primarysealingelement一个耐磨,静止的密封件2.Awearable,rotating,primarysealingelement一个耐磨,旋转的密封件3.Asecondarysealingelement二次密封4.Amechanicalloadingdevicetopressprimarysealingelements1and2againstoneanother,and使件1和件2相互贴合的机械装置5.Auxiliarycomponentstocompleteseal使密封更加完善的辅助件,.,12,不像一个机械密封而更像一个限制装置,需要泄漏否则将会灼伤.会磨损轴或轴套高功耗用来克服磨擦产品损失需要大量的水安装,维修和盘根调整需要停车时间泄漏导致设备破坏和摧毁,不可见泄漏、机械密封和盘根之间的泄漏率在1到100或者更好证明机械密封的寿命可达8到10年毫无故障无产品损失,节省水和能量可以节省成本安装后维修很少密封有潜在危害的物质时机械密封可以提供更好的安全性,GlandPackingv.MechanicalSeals盘根和机械密封,.,13,SPRINGFORCEFLUIDPRESSURE,fluidfilm(3-5microns),athinfilmofliquidformstheprimary(dynamic)sealbetweentherotatingandstationaryelements在旋转件和静止件之间形成很薄的液膜,FILMREACTION,PrimarySeal主密封,.,14,Faceslappedflattowithin1-3lightbands.,PrimarySealFilmThickness主密封膜厚度,.,15,PrimarySealFilmThickness主密封膜厚度,Fluidfilmthicknessisveryimportanttoothin-wear,causingearlysealfailuretoothick-visibleleakageMustbe:present-bewaredryrunning谨防干运转Stable稳定谨防磨损征兆clean-bewareabrasivewearsymptomsreasonableviscosity合理的黏度temperaturecontrolled受控的温度acceptablepressure允许的压力,.,16,PrimarySealFaceFlatness主密封平面,Iffacesnotflat,contactgeneratesheatExcessivewear-shortlife,1lightband=0.0000116inchor0.0003mm,.,Lubricant润滑剂,Separation分离面,MagnifiedSurfaceA放大面,MagnifiedSurfaceB放大面,Heat热量,TheSealingInterface密封面,LubricationPurpose:润滑目的Separatesurfaces分离两个面Preventcontactofhighsurfacepoints防止出现面接触Reducefriction/heatgeneration减少摩擦/生热,.,ProcessFluidActsasLubricantBetweenFaces流体在两个面之间充当润滑剂的过程,Gland密封端盖,PumpHousing泵腔,ProcessFluid工艺流体,InvisibleLeakage:不可见泄漏FluidEvaporatesUponReachingAtmosphere微量的泄漏在大气侧蒸发,PrimaryRing补偿环,MatingRing配合环,.,Gland密封端盖,PumpHousing泵腔,NoFluidOrDryRunning没有流体或者干运转,PrimaryRing补偿环,MatingRing配合环,WithoutLubrication,FacesRunDryAndOverheat没有润滑干运转导致过热,.,20,常用动环材料,Face(PrimaryRing)Materials动环材料Carbon-graphite碳石墨类resinimpregnated树脂浸渍（171）antimonyimpregnated金属锑浸渍（218）CarbonconvertedtoSiliconCarbide硅化石墨（121）CVR化学汽相反应硅化石墨CVD化学汽相沉积硅化石墨SolidSiliconCarbide碳化硅Sinteredsiliconcarbide无压烧结碳化硅(277)Reactionsiliconcarbide反应烧结碳化硅（088）Sinteredsiliconcarbidewithcontrolledporosity微孔碳化硅（584）TungstenCarbide碳化钨Cobaltbonded钴基碳化钨（025）Nickelbonded镍基碳化钨（005）,.,21,常用静环材料,Seat(MatingRing-Narrow)Materials静环材料Ceramic陶瓷99.7%AluminiumOxide氧化铝(059)SolidSiliconCarbide碳化硅Sinteredsiliconcarbide无压烧结碳化硅(277)Reactionsiliconcarbide反应烧结碳化硅（088）Sinteredsiliconcarbidewithcontrolledporosity微孔碳化硅（584）TungstenCarbide碳化钨Cobaltbonded钴基碳化钨（025）Nickelbonded镍基碳化钨（005）,.,22,SecondarySeal二次密封,Threebasicforms三种基本形式o-ringso型圈Wedges楔形环Bellows波纹管Elastomer橡胶的Metal金属的Formed成型的edgewelded焊接的PTFE,TwogroupsPusher推进式Sliding滑移o-ringswedgesNon-pusher非推进式Bellows风箱,.,TeflonBellows聚四氟乙烯波纹管,ElastomericBellows橡胶波纹管,HalfConvolution半波,WeldedMetalBellows焊接金属波纹管,VRingsV型圈,UCup杯型,Wedge楔形,EncapsulatedORing包覆O型圈,ORingO型圈,SecondarySealingElements二次密封,.,Pusher推进式,Non-Pusher非推进式,O-ringsecondarysealmustslidealongshaftassealfacewearsO型圈二次密封在密封面磨损的时候必须能够沿轴滑动,Bellowssecondarysealexpandstoaccommodatefacewear.Bellowstailisstationaryagainstshaft.波纹管伸长能够补偿密封面磨损,波纹管尾部与轴保持静止,vs.,Pushervs.Non-Pusher推进式/非推进式,.,25,SecondarySeal:Pusher二次密封：推进式,Asthefacemovesforwardtotakeupwear,theo-ringmovesforwardwiththeface,pushedbythehydraulicandspringpressures,.,26,SecondarySeal:Pusher二次密封：推进式,Advantages优点suddenfailureveryunlikely几乎不会突发意外事故higherpressurecapability-facenotstressed耐压性能高-应力变形小widechoiceofmaterialsforallcomponents所有成分的材料选择广泛fieldrepairable可修复的Disadvantages缺点hang-up(notlikelywhereo-ringiswellisolated)挂起permanentset/pressureproblems(causehang-up)长久放置/压力问题（导致挂起）excellentshaftsurfacefinishrequired要求轴的表面光滑maximumtemperature+260C最高温度+260C,.,27,PusherSeal:Hang-up推进式密封：挂起,Productleakagesolidifies/crystallises/polymerises,Preventso-ringpushingforward-leakageincreases阻止O形圈迅速的推进-泄漏增加,Anexternalquenchwillpreventhang-up外部的冲洗可防止挂起,.,28,SecondarySeal:O-Ring二次密封：O型圈,Type8B1,.,29,SecondarySeal:Wedge二次密封：楔形环,.,30,SecondarySeal:Non-Pusher二次密封：非推进式,Bellowsflexestotakeupwear,misalignmentandaxialplay,Finemachinedshaftsurfacerequired精掣轴表面Donotuseagoodlubricant-neverusesilicongrease,.,31,SecondarySeal:Bellows二次密封：波纹管,.,32,SecondarySeal:MetalBellows二次密封：金属波纹管,statico-ring静止o型圈,.,33,Type10T,Type10R,SecondarySeal:PTFEBellows二次密封：PTFE波纹管,.,TertiarySeal三次密封,.,35,TertiarySeal三次密封,Preventsleakageroundmatingring防止静环周围的泄漏Sometimesalsopreventsmatingringrotation有时也防止静环旋转,.,36,TertiarySeal三次密封,Fourbasictypes四种基本的形式O-ringsO型圈Elastomers橡胶SeatRings(squareorrectangularsection)PTFEgraphiteCupRingselastomersGasketsorFlatJointsPTFEcompressedfibre非石棉的压缩纤维,.,TertiarySeal:O-ring三次密封：O型环,.,TertiarySeal:O-ring三次密封：O型环,.,TertiarySeal:O-ring三次密封：O型环,.,40,TertiarySeal:SeatRing三次密封：静环,.,TertiarySeal:CupRubber三次密封：,.,SpringDesignFeatures弹簧设计特点,Springs弹簧ProvideTheInitialClosingForce提供初始闭合力AreVeryImportantAtLowPressures低压下很重要AreNotSoImportantAtHighPressures高压下不重要,.,DesignFeatures设计特点,Springs弹簧Single单弹簧Multiple多弹簧Bellows波纹管Wave波形,.,DesignFeatures设计特点,Springs弹簧HighSpeedSealsUseStationarySprings(5000ft/minTypicalBreakPoint)高速机械密封使用静止弹簧(5000ft/min典型的分界点),.,DesignFeatures设计特点,Springs弹簧Corrosion腐蚀Clogging堵塞UniformityOfLoad负荷一致Inventory批量,.,DriveMechanism驱动机械MustTransmitTorque必须能够传递转矩MustAllowAxialMovement(PrimaryRing)必须能够使动环轴向运动,TypesofDriveMechanisms驱动机械的类型,.,PinDrive销驱动,DentDrive凹窝驱动,SlotandEar槽和支耳,SpringDrive弹簧驱动,SetScrewDrive定位螺丝驱动,SnapRingDrive卡环驱动,ElastomerDrive橡胶驱动,KeyDrive键驱动,TypesofDriveMechanisms驱动机械的类型,.,48,SealMaterials密封材料,MaterialConsiderations材料需要考虑Temperature温度ThermalExpansion热膨胀ThermalConductivity导热性ChemicalResistance化学稳定性Wear磨损性Flexibility弹性Manufacturability制造能力Cost成本Availability实用性,.,49,PrimarySealMaterials主密封材料,Face(PrimaryRing-Narrow)Materials窄环材料Carbon-graphite炭-石墨resinimpregnated浸渍树脂antimonyimpregnated浸渍金属锑CarbonconvertedtoSiliconCarbide硅化石墨,.,50,PrimarySealMaterials主密封材料,CarbonconvertedtoSiliconCarbide,.,51,SolidSiliconCarbid