外文翻译液位检测.docx

外文翻译液位检测.docx

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外文翻译液位检测

附录C

LiquidLevelMeasurement

Chemicalindustrywiththeprogressofscienceandtechnologygotrapiddevelopment,inordertomaketheequipmentsafeandreliableoperation,andcanbeutmosttoimproveproductquantityandquality,toeffectivelyoperateautomaticallyandprocessadjustment,realizethescientificmanagementfortheenterprisetoprovidethenecessarymaterialandenergyofaccuratedata,mustbeinproductionintheprocessofpressure,flow,level,temperature,chemicalcompositionofvariousparameterssuchastimely,accuratemeasurement.

Generallytheprocessofcontainers,tanks,towers,tankofliquidsurfacepositionlevel,slotbucket,cans,andwarehouseChuFasolidblock,theaccumulationofparticles,powderheightandsurfacepositioniscalledamateriallevel;Twonotfluidboundarybetweentheheightandtheliquidandsolidseparationheightiscalledinterfaceposition,thepositionofassemblylevel,materiallevel,liquidlevelinterface.

Materiallevelmeasurementtocorrectlymeasurethecontainerstoragecapacityorquality,knowcontainerlevelofhighandlowandadjustatanytime,inthematerialleveltomaintaintherequiredheight.

Materiallevelmeasurementinchemicalprocess,notonlyundernormaltemperature,atmosphericpressureandordinarymedium,materiallevel,liquidlevelmeasurementoftheinterface,butalsooftenmeethightemperature,lowtemperature,highpressure,inflammableandexplosive（negativetemperature）.Viscosityandfoam,boilingdielectricmateriallevelmeasurementproblems.

Inordertoadapttothecharacteristicsofchemicalobjects,tomeettherequirementsofthechemicalprocessmateriallevelmeasurement,therearemanymateriallevelmeasurementandinstrumentation.

1.Ultrasonicliquidlevelmeterandradarmateriallevelmeter

（1）ultrasonicliquidlevelmeter

Materiallevelmeasurementprocess,theultrasonicsignal,issuedbytheultrasonicprobe,theliquidorsolidmaterialsurfaceafterlaunchback,bythesamesensorreceiving,ultrasonicmeasurementofthewholerunningtime,soastorealizethemeasurementofmateriallevel,acousticvelocitytransmissionoftheultrasonicpulse,fromtransmittingtoreceivingtoultrasonicpulseneedtimeintervalandthetransducertothesurfaceofthemeasuredmediumisproportionaltothedistance.

Emitultrasoniclevelmeterpulse,nottheechoofdetectionatthesametime.Duetothelaunchoftheultrasonicpulsewidthhasacertaintime,andafterlaunchtheultrasonicsensorandaftershocks,duringcannotdetecttheecho,sofromthestartdownthesurfaceoftheprobeashortdistancecan'tnormalinspection,thisdistanceiscalledblindspots.Wasthehighestlevelsuchasintotheblindarea,detectinstrumentwillnotbeabletocorrectly,therewillbeerror,ifnecessary,heightenedlevelmetercanbeinstalled.

Ultrasonicliquidlevelmeteralsohasshortcomings,theultrasonictransmissionbygasinterference,levelsurfacebubbles,corrugated,etc,theultrasonictransmissionbygasinterference,levelsurfacebubbles,corrugated,etc.,theultrasonicreflectioneffect.Materialisvolatile,liquidgasentrapment,thecontainerbyvibration（e.g.,motors）areinstalledonthecontainercan'tuseultrasonicliquidlevelmeter.

（2）radarmateriallevelmeter

RadarlevelgaugeUSESlaunch-reflection-receiveworkmode.Radarlevelmeterantennaemitelectromagneticwave,thewavereflectedbythemeasuredobjectsurface,againbytheantenna,theelectromagneticwavefromtransmittingtoreceivingtimeisproportionaltothedistancetotheliquidsurface.Inpractice,therearetwokindsofradarlevelgaugemeansthefrequencymodulationcontinuouswaveandpulsewave.Liquidlevelmeteradoptsfrequencymodulationwavetechnology,powerconsumptionisbig,thefourwiresystem,shouldbeusedinelectroniccircuitiscomplicated.Andtheradarpulsewavetechnologylevelgauge,lowpowerconsumption,easytoimplementessentialsafety,highprecision,widerapplicationscope.

Radarlevelgaugemeasuringtheelectromagneticwavescanpassthroughavacuum,don'tneedatransmissionmedium,isnotaffectedbyair,steam,groovevolatilefogeffect,canbeusedforsuchascoarsebenzenevolatilemediumlevelmeasurement.

Radarlevelmetercanbeusedforalmostalloftheliquidlevelmeasurement.Electromagneticwaveonthesurfacelevelwhenfiring,signalattenuation,whenthesignalattenuationthroughthehours,canleadtoradarlevelmetercannotdetectenoughelectromagneticwavesignal,theconductivemediumcanbeaverygoodreflectionofelectromagneticwave,thedielectricconstantisgreaterthan1.5nonconductivemediumdielectricconstantwas1.0（air）willalsobeabletoguaranteesufficientreflectionwave,dielectricconstant,thegreaterthereflectionsignal.Inpractice,almostallmediumcanreflectenoughofreflectionwave.

（3）radarlevelgauge,ultrasonicliquidlevelmeter

Ultrasoundandradaristhemainmeasuringprincipleisdifferent,leadtotheirdifferentapplicationoccasions,radarisgiventhatthedielectricconstantofthemeasuredsubstance,whichisgiventhatthedensityofthematerialbeingmeasured,sothelowdielectricconstantmaterialradarmeasurementswillbeeffecttosellatadiscountgreatly,thesolidmatteringeneral,pushharder,anotherwaveofdifferentmeansoftransmissioncomponents,suchasultrasonicwavewaslaunchedbythevibrationofthepiezoelectricmaterial,soitiscanbeusedinhigherpressureornegativepressureofthesituation,usuallyonlyintheatmosphericpressurecontainers.Theradarcanbeusedintheprocessofhighpressuretank.RadaremissionAngleisbiggerthanultrasound,smallcontainersorelongateddon'trecommendusingnon-contactradar,generallyrecommendadirectorradar.Finallyisthetemperatureontheaccuracy,ofcourse,mustbehigherthantheultrasonic,radarmustusehighresolutionradarinthetank,withoutultrasonic.Asfortheprice,usuallyultrasonic,lowerthantheradarinawiderangeofcoursesomeultrasonicpriceisalsohigh.Suchastherangeof6-70meters,thepreferredultrasonicliquidlevelmeter.Payattentiontothestirringgroove,groovewalladhesioncanproduceinterferenceofthereflectedwave,levelmeasurement,theinstallationistochoosetheappropriateinstallationposition,soastoavoidtheinterferenceofthesefactors.

Leveltwocategories,includingliquidlevelandmateriallevel.Liquidlevelandliquidlevelindicatorandtwocontinuouslevelmeasurement.Liquidlevelindicatoristhelevelofseveralfixedpositionmeasuring,usedinliquidlevelofupperandlowerlimitalarm,etc.Continuouslevelmeasurementistomeasureliquidlevelcontinuously,itiswidelyusedinmanyfieldssuchaspetroleum,chemicalindustry,foodprocessing,haveveryimportantsignificance.Formorethan20kindsofcontinuouslevelmeasurementmethodforcomparativeanalysis.Glasstube,glassplate,doublecolorwatermethod.

Manualgaugingglasstubemethod:

thismethodisusingtheprincipleofcommunicatingvessels,levelscalereaddirectlyfromtheinstructions.Glassplatemethod:

glasswhichcanbeinstalledthroughconnectorscanalsobeinstalledinthecontainerwallopenings,andseriesafewpieceofglasstoincreasetherange.Numericalscalereaddirectlyfromtheglassplatelevel.

Doublecolorgaugemethod:

thismethodusingtheopticalprinciple,makewatershowsgreen,andmakethewatervaporshowsred,whichindicatethewaterlevel.

Artificialgaugingmethod:

themethodisusedformeasuringoiltankliquidlevel.Whenmeasuring,thesurveyorgaugeSurveyortovolumeoftheoildipstickintooil,andfiledwhenfeetleadcontactwiththetankbottomoildipstick.Accordingtothequantityofoiltracesontheoildipstick,readouttheoillevelheight;Endaccordingtothequantityofoildipsticktestcreamcolorchangetodeterminetheheightofthewatercushionlayer,todeterminehighoilandhighwaterabove4methodsareartificialmeasurementmethod,measurementissimple,theadvantagesofhighreliability,intuitive,andlowcost.

Blowingmethod,differentialmethod,HTGblowingmethod:

becauseoftheblowpipeapproximationisequaltothefluidcolumnpressureinthestaticpressure,thusP=rhogHtypeofrho-liquiddensity;H-level.SotheliquidlevelismeasuredbythestaticpressurePcanbeH.Strongmethodsuitableformeasuringthecorrosivegasblowing,havesuspendedmaterialcontentintheliquid,andismainlyusedinthemeasurementaccuracyisnothigh.

Differentialpressuremethod:

theopencontaineroratmosphericvessels,valvesandgasphasepressurepipelinesaves.BasedontherelationshipbetweendifferentialpressureandliquidlevelΔP=P2-P1=rhogHtype:

ΔP-positiveandnegativepressurechamberpressuretransmitter;P2andP1-ledtubepressure;H-level.Differentialpressuretransmitterwillpressuredifferencetransformationfor4~20mAdcsignal.Ifthepressureinthemeasuringrangelowerlimitofthecorrespondingoutputsignalisgreaterthanorlessthan4mA,areallneedtoadjustthemigrationzeromigrationtechnologysuchasspring,isequalto4mA.HTGmethod:

thismethodisappliedtodifferentialpressureoiltankliquidlevelmeasurement.

Buoymethod:

thismethodUSESthemiddlemaglevbarrelwithholesasliquidlevelsensor.Stainlesssteelcasingfrombuoyholethroughthemiddle,betweenfixedtotheroofandbottom.Liquidlevelchangedrivenmaglevhollowtube（permanentmagnet）hidesinsidecanmoveupanddownthecasing,andattractthecasingofmagnetcanmoveupanddownthecasingwall,secondaryinstrument|instrumentaccordingtothemovingmagnetvolumetocalculatetheliquid