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1、自动化仪表在垃圾填埋场渗滤液处理系统中的应用2Theapplicationoftheautomaticinstrumentinthefiltertreatmentsystemofthelandfillisonpage29ngns3.FlowmeasurementFlowmeasurementisdividedintotwokinds,onefortrafficdetection,participateinprocesscontrol,toimprovethelevelofproductionautomation
2、,improvetheproductionprocessconditions,thepurposeofimprovingproductqualityandproduction.Anotherkindofmeasure,whichisusedforflow,notonlymeasuretheamountofthefiltrate,butalsothebasisofthecalculationofthemaintechnicalandeconomicindicators.Threeoftheeightmaineco
3、nomicindicatorsforwatercompaniesarebasedondatameasuredbyflowmeters.Thetypeofflowmetershouldconsiderthefollowingfactors:(1)anytypeofmetermustbecertifiedbythenationalmetrologicaldepartment.(2)theflowmeteritselfislessstressful.(3)accordingtotheindustryrequireme
4、nts,theaccuracyofthemetershouldbenolessthan2.5.Theinstallationfieldconditionsshallsatisfytherequirementsoftheselectedflowmeterforthestraightpipesection.(5)theselectedflowmetershallbesuitablefortheinstallationofon-siteenvironmentalconditionssuchastemperature,
5、humidityandelectromagneticinterference.(6)theselectedflowmetershouldbesuitablefortheliquidmediumtobetested.Atpresent,themostusedinengineeringdesigniselectromagneticflowmeterandultrasonicflowmeter.A.electromagneticflowmeterTheprincipleofelectromagneticflowmet
6、eristheapplicationofthelawofelectromagneticinductionofthefarad,whichconsistsofsensorsandconverters.Inmeasurement,theliquiditselfisaconductor,andthemagneticfieldisgeneratedbytwocoilsinstalledinthepipe.Byacordcexcitationcoil,themagneticfieldactingonthepipeflow
7、ofliquid,inpipelineisameasurementofbodycorrespondingtotheaverageflowvelocityVvoltage,andthevoltagehasnothingtodowiththevelocitydistributionoffluid.Twoelectrodesinsulatedfromthepipedetectthesensorvoltageoftheliquid.Thefielddirection,theflowdirectionandtherela
8、tivepositionsofthetwoelectrodesareperpendiculartoeachother.Advantagesofelectromagneticflowmeter:(1)tomeasuretheeffectoftemperature,pressure,orviscosityoftheliquid.Nopressureloss.(3)themeasuringa
