氣壓系統(tǒng)中英文對照外文翻譯文獻

PAGE中英文對照外文翻譯文獻(文檔含英文原文和中文翻譯)PneumaticsystemandvariousvalvebasicintroductionPneumaticsystemsusepressurizedgasestotransmitandcontrolpower.Asthenameimplies,pneumaticsystemtypicallyuseair(ratherthansomeothergas)asthefluidmediumbecauseairisasafe,low-cost,andreadilyavailablefluid.Itisparticularlysafeinenvironmentswhereanelectricalsparkcouldigniteleaksfromsystemcomponents.Inpneumaticsystems,compressorsareusedtocompressandsupplythenecessaryquantitiesofair.Compressorsaretypicallyofthepiston,vaneorscrewtype.Basicallyacompressorincreasesthepressureofagasbyreducingitsvolumeasdescribedbytheperfectgaslaws.Pneumaticsystemsnormallyusealargecentralizedaircompressorwhichisconsideredtobeaninfiniteairsourcesimilartoanelectricalsystemwhereyoumerelyplugintoanelectricaloutletforelectricity.Inthisway,pressurizedaircanbepipedfromonesourcetovariouslocationsthroughoutanentireindustrialplant.Thecompressedairispipedtoeachcircuitthroughanairfiltertoremovecontaminantswhichmightharmthecloselyfittingpartsofpneumaticcomponentsuchasvalvesandcylinders.Theairthenflowsthroughapressureregulatorwhichreducesthepressuretothedesiredlevelfortheparticularcircuitapplication.Becauseairisnotagoodlubricant(containsabout20%oxygen),pneumaticssystemsrequiredalubricatortoinjectaveryfinemistofoiltheairdischargingfromthepressureregulator.Thispreventswearofthecloselyfittingmovingpartsofpneumaticcomponents.Freeairfromtheatmospherecontainsvaryingamountsofmoisture.Thismoisturecanbeharmfulinthanitcanwashawaylubricantsandthuscauseexcessivewearandcorrosion.Hence,incomeapplications,airdriersareneededtoremovethisundesirablemoisture.Sincepneumaticsystemsexhaustdirectlyintotheatmosphere,theyarecapableofgeneratingexcessivenoise.Therefore,mufflersaremountedonexhaustportsofairvalvesandactuatorstoreducenoiseandpreventoperatingpersonnelfrompossibleinjuryresultingnotonlyfromexposuretonoisebutalsofromhigh-speedairborneparticles.Thereareseveralreasonsforconsideringtheuseofpneumaticsystemsinsteadofhydraulicsystems.Liquidsexhibitgreaterinertiathandogases.Therefore,inhydraulicsystemstheweightofoilisapotentialproblemwhenacceleratinganddeceleratinganddeceleratingactuatorsandwhensuddenlyopeningandclosingvalves.DuetoNewton’slawofmotion(forceequalsmassmultipliedbyacceleration),theforcerequiredtoaccelerateoilismanytimesgreaterthanthatrequiredtoaccelerateanequalvolumeofair.Liquidsalsoexhibitgreaterviscositythandogases.Thisresultsinlargerfrictionalpressureandpowerlosses.Also,sincehydraulicsystemsuseafluidforeigntotheatmosphere,theyrequirespecialreservoirsandno-leaksystemsuseairwhichisexhausteddirectlybackintothesurroundingenvironment.Generallyspeaking,pneumaticsystemsarelessexpensivethanlessexpensivethanhydraulicsystems.However,becauseofthecompressibilityofair,itisimpossibletoobtainprecisecontrolledactuatorvelocitieswithpneumaticsystems.Also,precisepositioningcontrolisnotobtainable.Whilepneumaticpressuresarequitelowduetopressurescanbeashighas10,000psi.Thus,hydraulicscanbehigh-powersystems,whereaspneumaticsareconfinedtolow-powerapplications.Industrialapplicationsofpneumaticsystemsaregrowingatarapidpace.Underneathintroductioniswidelyusedinallkindsofpneumaticsystemvalve.Valveisawidelyusedmechanicalproductineachcountry'seconomy.Youcanfindvalvescommonlyusedinthefollowingfieldslikeoil,naturegas,coal,metallurgy,mining,refinery,pipetransportation,petrochemical,chemical,pharmacy,foodproduction,powerplant,watersupply/drainage,heatsupply,airsupply,marine,vehicle,airplane,spacecraft,military,newtech,irrigationandmanyotherflowingsystems.Thereareself-drivenvalvesandoperatedvalves.Self-drivenvalves(likesafetyvalve,reliefvalve,steamtrap,checkvalve)arefunctioningbyutilizingitsmechanicaldesignorthepressure,directionofitsflowmedium.Operatedvalves(likegatevalve,globevalve,ballvalve,butterflyvalve)arefunctioningbyactuator(manual,electric,hydraulic,pneumaticetc.)orthepressure,flowdirectionofitsmedium.Duetothedifferencesofpressure,temperature,flow,andphysical-chemicalcharacterofitsmedium,therearedifferentrequirementsindesigningandapplyingthepipelinesystem.Thereforetherearenumeroustypesofvalve.GASVALVEFromtheairvalveoperatingprinciplesofview,airvalveperformancewilldirectlyaffecttheworkofcompressortanks,airvalveforthefollowingrequirements:resistancelossessmall.Airvalvesizeandairflowresistancelossesofvalvesalwaysspeedandthesizeofthespring-loadededge.Gashigherspeed,thegreatertheenergylosses;Spring-loadededgetoolarge,thelossisgreatresistance,thesizeoftheairvalvemovementdesignguidelinestodeterminethereasonablenessofthelaw.Airvalveclosedtimely,rapid,notleakclosedtoimprovetheefficiencyofmachinesandextendeduseperiod.Longlife,workreliable.Lifeisthemainfactorrestrictingairvalveandspring-loadedvalvesquality,thegenerallong-termcontinuousoperationofthecompressorstolife80hours;Formobile,short-termorintermittentoperationofcompressors,mayrequireslightlymore.Airvalveandpiston-typecompressorsaretotheimportantcomponentsisoneofthecomponentseasilydamaged.Itwillhaveadirectimpactonthedisplacementcompressors,powerconsumptionandreliabilityofoperation,thecurrentcompressorisfastdirection,androtationalspeedlimitisoneofthekeyissuesinimprovingairvalve.Piston-typecompressorstypicallyusethe"automaticvalve"thattheairvalveisopenedandclosedvalvesonthepressureonbothsidestoachievepoor,andthereisnootherdrive.PNEUMATICVALVEPneumaticvalvesregulatethetemperatureinthecontextnominalpressureandmayadjustvariousfluids,gasesandsteam,pneumatic-valveclosed,leakagesmall.Pneumatic-valveattheroleoftheimplementingagenciescouldreachagasopenorgasshutpurposes.Pneumaticvalvesregulatethepneumaticenforcementagenciesandregulatoryvalvestwo.Enforcementagenciestopromotetheimplementationofdevicesinstalled,itcompressedair-driven,exportthrust;Regulationvalvesarepartoftheimplementationofdevicestoregulatedirectcontactwiththemedia,regulatorymediumflow.Thepneumatic-valvestructurewithsimple,reliableoperation,exportthrustlargemaintenanceconvenientandinexpensive,suchasfireblastmeritspneumatic-valvewidelyusedforchemical,oil,metallurgical,electrical,textileandotherindustrialproductionprocessesautopilotandremotecontrol.PRESSUREREGULATINGVALVEpressureregulatingvalveisarelianceonexternalenergytransfermediumitselfwaspressurechangespressure-typeautomaticadjustmentofproduct,youcanadjustthevalveinthepressureequipmentdebuggingprocessinaccordancewiththeirownprocessespressureregulatingvalvesfortheguidecommandsystemsetpressureafterpressureregulatingvalvesvalue,pressureregulatingvalveswillbenaturalgaspressureregulatingvalves,thepressureforyoutosetandautomaticallymaintainitsconstant,pressureregulatingvalvesinthecontrolroomforyourremotecontroloxygenflowdownstream.Flowwillbeusedforon-siteoxygenpressureregulationandfeedbacktocontroltheactualprocessparameterstocontrolthedistance.Youcaneasilyadjusttheoxygenpressure.氣壓系統(tǒng)及各種閥門的基本介紹氣壓系統(tǒng)是用壓力氣體傳遞和控制動力，正如名稱所表明的那樣，氣壓系統(tǒng)通常用空氣（不用其他氣體）作為流體介質(zhì)，因為空氣是安全、成本低而又隨處可得的流體，在系統(tǒng)部件中產(chǎn)生電弧有可能點燃泄漏物的場合下（使用空氣作為介質(zhì)）尤其安全。在氣壓系統(tǒng)中，壓縮機用來壓縮并供應(yīng)所需的空氣。壓縮機一般有活塞式、葉片式和螺旋式等類型。壓縮機基本上是根據(jù)理想氣體法則，通過減小氣體體積來增加氣體壓力的。氣壓系統(tǒng)通?？紤]采用大的中央空氣壓縮機作為一個無限量的氣源，這類似于電力系統(tǒng)中只要將插頭插入插座便可獲得電能。用這種方法，壓力氣體可以從氣源輸送到整個工廠的各個角落，壓力氣體可通過空氣濾清器除去污物，這些污物可能會損壞氣動組件的精密配合部件如閥和氣缸等，隨后輸送到各個回路中，接著空氣流經(jīng)減壓閥以減小氣壓值適合某一回路使用。因為空氣不是好的潤滑劑（包括20%的氧氣），氣壓系統(tǒng)需要一個油霧器將細小的油霧注射到經(jīng)過減壓閥的空氣中，這有助于減少氣動組件精密配合運動件的磨損。由于來自大氣中的空氣含不同數(shù)量的水分，這些水分是有害的，它可以帶走潤滑劑引起過分磨損和腐蝕，因此，在一些使用場合中，要用空氣干燥器來除去這些有害的水分。由于氣壓系統(tǒng)直接向大氣排氣，會產(chǎn)生過大噪聲，因此可在氣閥和執(zhí)行組件排氣口安裝消聲器來降低噪聲，以防止操作人員因接觸噪聲及高速空氣粒子有可能引發(fā)的傷害。用氣動系統(tǒng)代替液壓系統(tǒng)有以下幾條理由：液體的慣性遠比氣體大，因此，在液壓系統(tǒng)中，當執(zhí)行組件加速減速和閥突然開啟關(guān)閉時，油液的質(zhì)量便是一個潛在的問題，根據(jù)牛頓運動定律（力等于質(zhì)量乘以加速度），產(chǎn)生加速運動油液所需力要比加速同等體積空氣所需的力高出許多倍。液體比氣體具有更大的粘性，這會因為內(nèi)摩擦而引起更大的壓力和功率損失；另外，由于液壓系統(tǒng)使用的液體要與大氣隔絕，故它們需要特殊的油箱和無泄漏系統(tǒng)設(shè)計。氣壓系統(tǒng)使用可以直接排到周圍環(huán)境中的空氣，一般來說氣壓系統(tǒng)沒有液體系統(tǒng)昂貴。然而，由于空氣的可壓縮性，使得氣壓系統(tǒng)執(zhí)行組件不可能得到精確的速度控制和位置控制。氣壓系統(tǒng)由于壓縮機局限，其系統(tǒng)壓力相當?shù)停ǖ陀?50psi），而液壓力可達10000psi之高，因此液壓系統(tǒng)可以是大功率系統(tǒng)，而氣動系統(tǒng)僅用于小功率系統(tǒng)。下面介紹廣泛應(yīng)用于氣壓系統(tǒng)的各種閥門。閥門是國民經(jīng)濟建設(shè)中使用極為廣泛的一種機械產(chǎn)品。閥門在石油、天然氣、煤炭、冶金、和礦石的開采、提煉加工和管道輸送系統(tǒng)中；在石油化工、化工產(chǎn)品，醫(yī)藥和食品生產(chǎn)系統(tǒng)中；在水電、火電和核電的電力生產(chǎn)系統(tǒng)中；在城建的給排水、供熱和供氣系統(tǒng)中；在冶金生產(chǎn)系統(tǒng)中；在船舶、車輛、飛機、航天以及各種運動機械的使用流體系統(tǒng)中；在國防生產(chǎn)以及新技術(shù)領(lǐng)域里；在農(nóng)業(yè)排灌系統(tǒng)中都有大量的需求。閥門分