《水處理技術(shù)（雙語）》課件-離心泵

Centrifugalpumps(I)離心泵（上）離心泵的工作原理Theworkingprincipleofcentrifugalpump離心泵是根據(jù)離心力原理設(shè)計的，通過高速旋轉(zhuǎn)的葉輪葉片帶動液體轉(zhuǎn)動，將液體甩出，從而將液體延管路進(jìn)行輸送的機(jī)械。Centrifugalpumpisdesignedaccordingtotheprincipleofcentrifugalforce,throughthehigh-speedrotationoftheimpellerbladesdrivetherotationoftheliquid,theliquidwillbethrownout,sothattheliquidextendedpipelinefortransportmachinery.離心泵的工作原理Theworkingprincipleofcentrifugalpump離心泵的工作過程分為吸液過程和排液過程，其工作原理如下：Theworkingprocessofcentrifugalpumpisdividedintosuctionprocessanddischargeprocess,anditsworkingprincipleisasfollows.離心泵的工作原理Theworkingprincipleofcentrifugalpump排液過程：在泵啟動前，先用被輸送的液體把泵灌滿。啟動后，高速旋轉(zhuǎn)的葉輪帶動葉片間的液體作旋轉(zhuǎn)運動。

Drainageprocess:Beforethepumpisstarted,thepumpisfilledwiththeliquidbeingconveyed.Afterstarting,thehigh-speedrotatingimpellerdrivestheliquidbetweenthevanesforrotationalmovement.在離心力的作用下，液體便從葉輪中心被拋向葉輪外緣。

Undertheactionofcentrifugalforce,theliquidisthrownfromthecenteroftheimpellertotheouteredgeoftheimpeller.在這個過程中，葉片間的液體獲得了機(jī)械能，液體的靜壓力提高了，同時其動能也增加了。Inthisprocess,theliquidbetweenthebladesacquiresmechanicalenergy,thestaticpressureoftheliquidisincreased,whileitskineticenergyisalsoincreased離心泵的工作原理Theworkingprincipleofcentrifugalpump液體離開葉輪進(jìn)入泵殼后，由于泵殼中流道逐漸增大，液體流速逐漸降低，部分動能轉(zhuǎn)變?yōu)殪o壓能，至泵出口處，液體的靜壓力進(jìn)一步提高，最后進(jìn)入排出管。Aftertheliquidleavestheimpellerandentersthepumpcasing,astheflowchannelinthepumpcasinggraduallyincreases,theliquidflowrategraduallydecreases,andpartofthekineticenergyistransformedintostaticpressureenergytothepumpoutlet,thestaticpressureoftheliquidfurtherincreases,andfinallyentersthedischargepipe.因離心泵的排液是由于離心力的作用，故稱為離心泵。

Becausethedischargeofacentrifugalpumpisduetocentrifugalforce,itiscalledacentrifugalpump.離心泵的工作原理Theworkingprincipleofcentrifugalpump吸液過程：當(dāng)泵內(nèi)液體從葉輪中心被拋向葉輪外緣時，在葉輪中心處形成低壓區(qū)。Suctionprocess:Whentheliquidinthepumpisthrownfromthecenteroftheimpellertotheouteredgeoftheimpeller,alowpressureareaisformedatthecenteroftheimpeller.這樣，造成了吸入管貯槽液面與葉輪中心處的壓力差,貯槽內(nèi)的水被吸入葉輪中心，以補(bǔ)充被排出的液體，這就是離心泵的吸液過程。Thus,thepressuredifferencebetweentheliquidlevelofthesuctiontubereservoirandthecenteroftheimpelleriscaused,andthewaterinthereservoirissuckedintothecenteroftheimpellertoreplenishthedischargedliquid,whichisthesuctionprocessofthecentrifugalpump.圖為整臺離心泵Completecentrifugalpumps離心泵的工作原理Theworkingprincipleofcentrifugalpump若在啟動前泵內(nèi)未充滿液體，則泵內(nèi)存在空氣。Ifthepumpisnotfilledwithliquidbeforestarting,thereisairinthepump.由于空氣的密度比液體小得多，泵內(nèi)產(chǎn)生的離心力就很小，因而在吸入口處的真空度很低,貯槽液面與泵入口處的壓力差很小，不足以將貯槽內(nèi)的液體吸入泵內(nèi)。Becausethedensityofairismuchsmallerthantheliquid,thecentrifugalforcegeneratedinthepumpisverysmall,sothevacuumatthesuctioninletisverylow,andthepressuredifferencebetweenthereservoirlevelandthepumpinletisverysmall,whichisnotenoughtosucktheliquidinthereservoirintothepump.離心泵的工作原理Theworkingprincipleofcentrifugalpump由于泵內(nèi)存在空氣,啟動離心泵而不能輸送液體的現(xiàn)象，稱為“氣縛”。Duetothepresenceofairinsidethepump,thepumpcannotstarttheliquidtransferphenomenon,called"airbinding".在吸入管末端安裝底閥的目的也是為了在灌泵時，防止水泄漏，使泵內(nèi)容易充滿液體。Thepurposeofinstallingthebottomvalveattheendofthesuctionpipeisalsotopreventwaterleakagewhenfillingthepump,sothatthepumpcanbeeasilyfilledwithliquid.離心泵的結(jié)構(gòu)Structureofcentrifugalpump離心泵主要由泵殼、葉輪和軸封裝置三部分構(gòu)成。離心泵的主要零件可參考圖1-2。Centrifugalpumpismainlycomposedofthreeparts:pumpcasing,impellerandshaftsealdevice.ThemainpartsofthecentrifugalpumpcanbereferredtoFigure1-2.離心泵主要有泵體、泵蓋、葉輪、泵軸、軸承及支架、密封裝置等組成離心泵的結(jié)構(gòu)Structureofcentrifugalpump1、泵殼PumpCasing離心泵的泵殼通常制成如同蝸殼狀的漸開線形，如圖所示。Thepumpcasingofacentrifugalpumpisusuallymadeintoaninvoluteshapelikeawormshell,asthepictureshows.葉輪在泵殼內(nèi)沿著蝸形逐漸擴(kuò)大的通道方向旋轉(zhuǎn)，愈接近液體的岀口，流道截面積愈大。Impellerinthepumpcasingalongtheworm-shapedgraduallyexpandingthedirectionofthechannelrotation,theclosertotheoutflowofliquid,thelargerthecross-sectionalareaoftheflowchannel.圖為泵體及泵內(nèi)液體液動情況Pumpbodyandliquidmovementinthepump液體從葉輪邊緣高速流出后，在泵殼中的蝸形通道作慣性運動時流速將逐漸降低，動能逐漸減小，在忽略位能改變的前提下，根據(jù)機(jī)械能守恒原理，減少的動能轉(zhuǎn)化為靜壓能，從而使液體獲得高壓，并因流速的下降減少了流動能量損失。Aftertheliquidflowsoutfromtheimpelleredgeathighspeed,theflowvelocitywillgraduallydecreasewhentheworm-shapedchannelinthepumpcasingmakesinertialmovement,andthekineticenergygraduallydecreases,underthepremiseofignoringthechangeofpotentialenergy,accordingtotheprincipleofmechanicalenergyconservation,thereducedkineticenergyisconvertedintostaticpressureenergy,sothattheliquidcanobtainhighpressureandreducetheflowenergylossduetothedecreaseofflowvelocity.所以泵殼不僅是收集由葉輪甩出液體的部件，還是一個能量轉(zhuǎn)換部件。Therefore,thepumpcasingisnotonlyaparttocollecttheliquidthrownoutbytheimpeller,butalsoanenergyconversionpart.離心泵的結(jié)構(gòu)Structureofcentrifugalpump離心泵的結(jié)構(gòu)Structureofcentrifugalpump2、葉輪（impeller）葉輪是離心泵的關(guān)鍵部件，一般有6~12片彎曲的葉片。Impelleristhekeycomponentofcentrifugalpump,generallyhas6~12curvedblades.按其機(jī)械結(jié)構(gòu)可分為閉式、半閉式和敞開式三種，如圖所示。Accordingtoitsmechanicalstructure,itcanbedividedintothreetypes:closed,semi-closedandopen,asthepictureshows.葉片兩側(cè)帶有前、后蓋板的稱為閉式葉輪，它適用于輸送清潔液體，多數(shù)離心泵均采用這種葉輪。Bothsidesofthebladewiththefrontandbackcoveriscalledclosedimpeller,itissuitablefortransportingcleanliquid,mostcentrifugalpumpsareusingthisimpeller.沒有前、后蓋板，僅由葉片和輪轂組成的稱為敞開式葉輪。只有后蓋板的稱為半閉式葉輪。Thereisnofrontandrearcoverplate,onlythebladeandhubiscalledopenimpeller.Thosewithonlytherearcoverplatearecalledsemi-closedimpellers.(a)閉式(b)半閉式(c)敞開式圖為葉輪impeller離心泵的結(jié)構(gòu)Structureofcentrifugalpump3、軸封裝置（Shaftsealingdevice）Shaftsealingdevice

泵軸與泵殼之間的密封稱為軸封，其作用是防止高壓液體沿軸外漏，同時也防止外界空氣吸入泵的低壓區(qū)，對泵軸與泵殼之間的間隙采用密封裝置，稱為軸封裝置。Thesealbetweenthepumpshaftandpumpcasingiscalledshaftseal.Itsfunctionistopreventthehighpressureliquidfromleakingoutalongtheshaft,andalsotopreventtheoutsideairfrominhalingintothelowpressureareaofthepump,andthesealdeviceisusedforthegapbetweenthepumpshaftandthepumpcasing,whichiscalledshaftsealdevice.常用的軸封裝置有填料密封和機(jī)械密封兩種。Therearetwotypesofshaftsealingdevicescommonlyused:packingsealandmechanicalseal.離心泵的結(jié)構(gòu)Structureofcentrifugalpump

填料密封Packingseal如圖所示。asthepictureshows.它主要由填料函殼、軟填料和填料壓蓋組成。Itismainlycomposedofpackinglettershell,softpackingandpackinggland.軟填料可選用浸油及涂石墨的方形石棉繩纏繞在泵軸上，或直接釆用橡膠密封圈密封，然后將壓蓋均勻壓緊，使填料緊壓在填料函殼和轉(zhuǎn)軸之間，達(dá)到密封的目的。Softpackingcanbeselectedfromoil-impregnatedandgraphite-coatedsquareasbestosropewrappedaroundthepumpshaft,ordirectlysealedwitharubberseal,andthentheglandisevenlypressed,sothatthepackingistightlypressedbetweenthepackinglettershellandtheshafttoachievethepurposeofsealing.圖為填料函packingbox1-填料函殼；2—軟填料；3—液封圈；1-stuffingboxshell;2-softpacking;3-liquidsealring.4一填料壓蓋；5—內(nèi)襯套4apackinggland;5-innerbushing離心泵的結(jié)構(gòu)Structureofcentrifugalpump機(jī)械密封MechanicalSeals對于輸送易燃、易爆或有毒、有腐蝕性液體時，軸封要求嚴(yán)格，一般采用機(jī)械密封裝置，如圖所示。Forconveyingflammable,explosiveortoxic,corrosiveliquids,theshaftsealrequirementsarestrict,andmechanicalsealingdevicesaregenerallyused,asthepictureshows.圖為密封圈Seals離心泵的結(jié)構(gòu)Structureofcentrifugalpump主要的密封元件是裝在軸上隨軸轉(zhuǎn)動的動環(huán)和固定在泵體上的靜環(huán)組成的密封面(一般動環(huán)用硬質(zhì)耐腐蝕金屬材料、靜環(huán)用浸漬石墨或耐腐蝕塑料制作以便更換)，兩個環(huán)的環(huán)形端面由彈簧使之平行貼緊，當(dāng)泵運轉(zhuǎn)時，兩個環(huán)端面發(fā)生相對運動但保持貼緊而起到密封作用，因此機(jī)械密封又稱為端面密封。Themainsealingelementisinstalledontheshaftwiththeshaftrotationofthedynamicringandfixedinthepumpbodyofthestaticringsealingsurface(generallydynamicringwithhardcorrosion-resistantmetalmaterials,staticringimpregnatedwithgraphiteorcorrosion-resistantplasticforreplacement),theringendfaceofthetworingsbythespringtomaketheparalleltight,whenthepumpisrunning,thetworingsendfacerelativemovementbutkeeptightandplayasealingrole,Therefore,themechanicalsealisalsocalledendfaceseal.圖為密封裝置示意圖Diagramofthesealingdevice1—螺釘；2—傳動座；3—彈簧；4—推環(huán)；1-screw;2-driveseat;3-spring;4-pushring.5—動環(huán)密封圈；6—動環(huán)；7—靜環(huán)；5-dynamicringseal;6-dynamicring;7-staticring.8-靜環(huán)密封圈；9一防轉(zhuǎn)銷8-Staticringseal;9-Anti-rotationpin離心泵的結(jié)構(gòu)Structureofcentrifugalpump與填料密封相比，機(jī)械密封的密封性能好，結(jié)構(gòu)緊湊，使用壽命長，功率消耗少，現(xiàn)已較廣泛地應(yīng)用于各種類型的離心泵中.Comparedwithpackingseal,mechanicalsealhasgoodsealingperformance,compactstructure,longservicelifeandlowpowerconsumption,andisnowmorewidelyusedinvarioustypesofcentrifugalpumps.但其加工精度要求高，安裝技術(shù)要求嚴(yán)，價格較高，維修也較麻煩。However,itrequireshighprocessingaccuracy,strictinstallationtechnology,higherpriceandmoretroublesomemaintenance.離心泵的性能Performanceofcentrifugalpumps（一）主要性能參數(shù)Mainperformanceparameters要正確選擇和使用離心泵，必須了解其性能，離心泵的主要性能有流量、揚(yáng)程、軸功率、效率和允許汽蝕余量等，常標(biāo)注在泵的銘牌上。

Tocorrectlyselectandusecentrifugalpumps,itisnecessarytounderstandtheirperformance.Themainpropertiesofcentrifugalpumpsareflowrate,head,shaftpower,efficiencyandallowablecavitationmargin,whichareoftenmarkedonthepumpnameplate.離心泵的性能Performanceofcentrifugalpumps1、流量（flow）離心泵的流量Q是指離心泵在單位時間內(nèi)輸送到管路系統(tǒng)中的液體體積，單位m3/h。離心泵的流量與泵的結(jié)構(gòu)、規(guī)格(主要為葉輪直徑和寬度)及轉(zhuǎn)速等有關(guān)。TheflowrateQofcentrifugalpumpisthevolumeofliquiddeliveredtothepipelinesystemperunittime,inm3/h.Theflowrateofcentrifugalpumpisrelatedtothepumpstructure,specifications(mainlytheimpellerdiameterandwidth)andspeed.

應(yīng)予指出，離心泵總是和特定的管路連接的，因此離心泵的實際流量還與管路特性有關(guān)。

Itshouldbenotedthatthecentrifugalpumpisalwaysconnectedtoaspecificpipeline,sotheactualflowrateofthecentrifugalpumpisalsorelatedtothecharacteristicsofthepipeline.離心泵的性能Performanceofcentrifugalpumps2、揚(yáng)程(壓頭)（Lift）離心泵的揚(yáng)程H是指離心泵對單位重量(1N)的液體所提供的有效機(jī)械能，單位為J/N或m。其大小取決于泵的結(jié)構(gòu)形式、規(guī)格(葉輪直徑、葉片的彎曲程度)、轉(zhuǎn)速、流量以及液體的密度和黏度。

TheheadHofacentrifugalpumpistheeffectivemechanicalenergyprovidedbythecentrifugalpumpperunitweight(1N)ofliquidinJ/Norm.Itssizedependsonthepump'sstructuralform,specifications(impellerdiameter,degreeofbendingofthevanes),speed,flowrate,andthedensityandviscosityoftheliquid.

離心泵的揚(yáng)程與柏努利方程中的外加壓頭是有區(qū)別的，外加壓頭是系統(tǒng)在流量一定的條件下對輸送設(shè)備提岀的做功要求，而揚(yáng)程是輸送設(shè)備在流量一定的條件下對流體實際做功能力。

ThereisadifferencebetweentheheadofacentrifugalpumpandtheexternalpressureheadinBernoulli'sequation.Theexternalpressureheadistheworkrequirementoftheconveyingequipmentundercertainflowconditions,whiletheheadistheactualworkcapacityofthefluidundercertainflowconditions.離心泵的性能Performanceofcentrifugalpumps3、軸功率（Shaftpower）離心泵的軸功率N是指泵軸所需的功率。當(dāng)泵直接由電動機(jī)帶動時，即為電機(jī)傳給泵軸的功率，單位為J/s或W。離心泵的軸功率與設(shè)備的尺寸、流體的黏度、流量等有關(guān)，其值可用功率表進(jìn)行測量。TheshaftpowerNofacentrifugalpumpreferstothepowerrequiredbythepumpshaft.Whenthepumpisdrivendirectlybythemotor,thatis,thepowertransmittedtothepumpshaftbythemotor,theunitisJ/sorW.Theshaftpowerofthecentrifugalpumpisrelatedtothesizeoftheequipment,theviscosityofthefluid,theflowrate,etc.,anditsvaluecanbemeasuredbyapowermeter.離心泵的性能Performanceofcentrifugalpumps4、效率Efficiency

離心泵在輸送液體的過程中，當(dāng)外界能量通過葉輪傳給液體時，不可避免地會有能量損失，即電機(jī)傳遞給泵軸的能量不能全部由液體獲得，致使泵的有效揚(yáng)程和流量都較理論值為低，通?？捎帽玫男师莵矸从吃O(shè)備能量損失的大小。

Centrifugalpumpintheprocessoftransportingliquid,whentheexternalenergythroughtheimpellertotheliquid,therewillinevitablybeenergyloss,thatis,themotortransfertothepumpshaftcannotbealltheenergyobtainedbytheliquid,resultingintheeffectiveheadandflowofthepumparelowerthanthetheoreticalvalue,usuallyavailablepumpefficiencyηtoreflectthesizeoftheenergylossofequipment.

離心泵的性能Performanceofcentrifugalpumps5、離心泵的能量損失Energylossofcentrifugalpumps主要包括以下幾項。（1）容積損失。（2）機(jī)械損失。（3）水力損失。Itmainlyincludesthefollowingitems.(1)Volumeloss.(2)Mechanicallosses.(3)Hydraulicloss.圖為

離心泵特性曲線圖離心泵的性能Performanceofcentrifugalpumps（二）特性曲線CharacteristicCurve實驗表明，離心泵在工作時的揚(yáng)程、功率和效率等性能參數(shù)并不是固定的，而是隨流量的變化而變化。

Experimentshaveshownthattheperformanceparameterssuchashead,powerandefficiencyofcentrifugalpumpsinoperationarenotfixed,butvarywiththeflowrate.離心泵的性能Performanceofcentrifugalpumps將實驗測得的離心泵的流量Q與揚(yáng)程H、軸功率N和效率η間的關(guān)系，繪制在一張圖上（圖1-13），稱為離心泵的特性曲線或工作性能曲線。

TherelationshipbetweentheexperimentallymeasuredflowrateQandheadH,shaftpowerNandefficiencyηofthecentrifugalpumpisplottedonagraph(Figure1-13),whichiscalledthecharacteristiccurveoroperatingperformancecurveofthecentrifugalpump.此曲線通常由泵的制造廠提供并附于離心泵樣本或說明書中，供用戶選擇和操作離心泵時參考。Thiscurveisusuallyprovidedbythepumpmanufacturerandattachedtothecentrifugalpumpsampleormanualfortheuser'sreferencewhenselectingandoperatingthecentrifugalpump.離心泵的安裝Installationofcentrifugalpumps（一）安裝位置InstallationLocation離心泵的安裝位置可高于液面，也可低于液面，必須在允許安裝高度之內(nèi)。Theinstallationpositionofthecentrifugalpumpcanbehigherthantheliquidlevelorlowerthantheliquidlevelandmustbewithintheallowableinstallationheight.圖為位置和汽蝕現(xiàn)象離心泵吸入液體是依靠葉輪的高速旋轉(zhuǎn)，在吸入口（葉輪中心處）形成負(fù)壓。Thecentrifugalpumpdrawsinliquidbyrelyingonthehigh-speedrotationoftheimpeller,whichcreatesanegativepressureatthesuctionport(atthecenteroftheimpeller).

如果離心泵離地面太高，引起液體有效氣蝕余量減少，液體進(jìn)入泵的低壓區(qū)時，其壓力小于液體輸送溫度下的飽和蒸汽壓力，液體沸騰而汽化，從而引起氣蝕，對泵本身造成損失。

Ifthecentrifugalpumpistoohighfromtheground,causingareductionintheeffectivecavitationmarginoftheliquid,theliquidentersthelowpressurezoneofthepump,itspressureislessthanthesaturatedvaporpressureatthetemperatureoftheliquiddelivery,theliquidboilsandvaporizes,thuscausingcavitation,causinglossestothepumpitself.離心泵的安裝Installationofcentrifugalpumps離心泵的安裝Installationofcentrifugalpumps

離心泵汽蝕現(xiàn)象:當(dāng)貯槽液面上的壓力一定時，吸上高度越高，則壓力越小。Centrifugalpumpcavitationphenomenon:Whenthepressureontheliquidsurfaceofthereservoiriscertain,thehigherthesuctionheight,thelowerthepressure.若吸上高度高至某一限度，壓力降至等于輸送溫度下液體的飽和蒸氣壓時，在泵進(jìn)口處，液體就會沸騰，大量汽化。Ifthesuctionheightishightoacertainlimit,thepressuredropstoequaltothesaturationvaporpressureoftheliquidattheconveyingtemperature,atthepumpinlet,theliquidwillboilandvaporizealot.液體汽化產(chǎn)生的大量氣泡隨液體進(jìn)入高壓區(qū)時，又被周圍的液體壓碎，氣泡所在空間形成真空，周圍的液體質(zhì)點以極大的速度沖向氣泡中心。Liquidvaporizationproducesalargenumberofbubbleswiththeliquidintothehigh-pressurearea,andthencrushedbythesurroundingliquid,wherethebubblespacetoformavacuum,thesurroundingliquidmassatgreatspeedtothecenterofthebubble.由于液體質(zhì)點互相沖擊，造成很高的瞬間局部沖擊壓力。Thehighinstantaneouslocalshockpressureiscausedbytheliquidmassesimpactingeachother.Thisgreatimpactcanmaketheimpellerorpumpcasingsurfacemetalparticlesoff,thesurfacegraduallyformedspots,smallcracks,andevenmaketheimpellerintoaspongeorthewholeoff,thisphenomenoniscalled"cavitation".這種極大的沖擊力可使葉輪或泵殼表面的金屬粒子脫落，表面逐漸形成斑點、小裂縫，甚至使葉輪變成海綿狀或整塊脫落，這種現(xiàn)象稱為“汽蝕”。離心泵的安裝Installationofcentrifugalpumps離心泵的安裝Installationofcentrifugalpumps汽蝕會引起以下后果：Cavitationcancausethefollowingconsequences.（1）產(chǎn)生振動和噪聲；Generationofvibrationandnoise.（2）產(chǎn)生大量氣泡，使泵的流量、揚(yáng)程、效率均明顯下降；

Generatealargenumberofairbubbles,sothattheflow,headandefficiencyofthepumparesignificantlyreduced（3）在葉片入口附近金屬疲勞剝蝕。

Fatiguespallingofmetalnearthebladeinlet.圖為離心泵發(fā)生氣蝕時性能曲線的變化離心泵的安裝Installationofcentrifugalpumps（二）安裝基礎(chǔ)InstallationBasics

離心泵的安裝工作必須根據(jù)設(shè)計圖紙進(jìn)行。對于安裝位置、安裝高度等都必須符合設(shè)計要求。

Theinstallationofthecentrifugalpumpmustbecarriedoutaccordingtothedesigndrawings.Fortheinstallationposition,installationheight,etc.mustmeetthedesignrequirements.但如果安裝時發(fā)現(xiàn)設(shè)計存在問題，要在現(xiàn)場及時解決。基礎(chǔ)的作用是支承并固定機(jī)組，使它運行平穩(wěn)，不致發(fā)生劇烈振動，更不允許產(chǎn)生基礎(chǔ)沉陷。However,ifproblemswiththedesignarefoundduringinstallation,theyshouldbesolvedonsiteintime.Theroleofthefoundationistosupportandfixtheunitsothatitrunssmoothlyanddoesnotvibrateviolently,nottomentionthatfoundationsubsidenceisnotallowedtooccur.離心泵的安裝Installationofcentrifugalpumps（三）水管的布置

ayoutofwaterpipes進(jìn)出水管的布置，對泵站安全運行和工程投資有較大影響，應(yīng)通過方案比較后確定，應(yīng)考慮管線的選擇，其布置原則是：Thearrangementoftheinletandoutletpipeshasagreaterimpactonthesafeoperationofthepumpingstationandengineeringinvestment,shouldbedeterminedthroughprogramcomparison,thechoiceofpipelineshouldbeconsidered,anditsarrangementprinciplesare.合理選擇管道直徑，管道直徑大，在相同流量下，液流速度小，阻力損失??；管道直徑小，會導(dǎo)致阻力損失急劇增大，使所選泵的揚(yáng)程增加，功率增加，成本和運行費用都增加。Reasonablechoiceofpipediameter,pipediameterpipediameterislarge,inthesameflowrate,liquidflowvelocityissmall,resistancelossissmall;pipediameterissmall,willleadtoasharpincreaseinresistanceloss,sothattheselectedpumpheadincreases,powerincreases,thecostandoperatingcostsareincreased.

泵的出口側(cè)必須裝設(shè)閥門（球閥或截止閥）和止逆閥。閥門用來調(diào)節(jié)泵的工況點，止逆閥在液體倒流時可防止泵反轉(zhuǎn)，并使泵避免水錘的打擊。

Theoutletsideofthepumpmustbeequippedwithavalve(ballvalveorglobevalve)andacheckvalve.Thevalveisusedtoregulatetheworkingpointofthepump,andthecheckvalvecanpreventthepumpfromreversingwhentheliquidflowsbackwards,andmakethepumpavoidwaterhammerblow.離心泵的安裝Installationofcentrifugalpumps離心泵的安裝Installationofcentrifugalpumps（四）振動、噪音的防治Vibration,noisepreventionandcontrol離心泵使用時發(fā)現(xiàn)泵振動及噪音異常，應(yīng)立即停機(jī)作檢查。Whenthecentrifugalpumpisusedandabnormalpumpvibrationandnoisearefound,itshouldbestoppedimmediatelyforinspection.（1）泵基礎(chǔ)是否牢靠whetherthePumpfoundationissecure當(dāng)發(fā)生振動時，Whenvibrationoccurs,首先應(yīng)檢查離心泵的地腳螺栓是否緊固。若未緊固會造成離心泵震動。

Firstofall,youshouldcheckwhetherthegroundboltsofthecentrifugalpumparetightened.Ifnottightened,itwillcausethecentrifugalpumptovibrate.還要考慮地腳基礎(chǔ)強(qiáng)度是否夠用，有時由于設(shè)計原因，基礎(chǔ)偏軟也能引起震動。

Alsoconsiderwhetherthefootingfoundationstrengthissufficient,sometimesduetodesignreasons,thefoundationissoftcanalsocausevibration.離心泵的安裝Installationofcentrifugalpumps（2）聯(lián)軸器找正

Couplingalignment