EPA Method 14

886METHOD14-DETERMINATIONOFFLUORIDEEMISSIONSFROMPOTROOMROOFMONITORSFORPRIMARYALUMINUMPLANTSNOTE:Thismethoddoesnotincludeallofthespecifications(e.g.,equipmentandsupplies)andprocedures(e.g.,samplingandanalytical)essentialtoitsperformance.Somematerialisincorporatedbyreferencefromothermethodsinthispart.Therefore,toobtainreliableresults,personsusingthismethodshouldhaveathoroughknowledgeofatleastthefollowingadditionaltestmethods:Method1,Method2,Method3,Method5,Method13A,andMethod13B.1.0ScopeandApplication.1.1Analytes.AnalyteCASNo.SensitivityTotalfluoridesasFluorine7782-41-4Notdetermined1.2Applicability.Thismethodisapplicableforthedeterminationoffluorideemissionsfromroofmonitorsatprimaryaluminumreductionplantpotroomgroups.1.3DataQualityObjectives.Adherencetotherequirementsofthismethodwillenhancethequalityofthedataobtainedfromairpollutantsamplingmethods.2.0SummaryofMethod.8872.1Gaseousandparticulatefluorideroofmonitoremissionsaredrawnintoapermanentsamplingmanifoldthroughseverallargenozzles.Thesampleistransportedfromthesamplingmanifoldtogroundlevelthroughaduct.ThefluoridecontentofthegasintheductisdeterminedusingeitherMethod13AorMethod13B.Effluentvelocityandvolumetricflowratearedeterminedusinganemometerslocatedintheroofmonitor.3.0Definitions.Potroommeansabuildingunitwhichhousesagroupofelectrolyticcellsinwhichaluminumisproduced.Potroomgroupmeansanuncontrolledpotroom,apotroomwhichiscontrolledindividually,oragroupofpotroomsorpotroomsegmentsductedtoacommoncontrolsystem.Roofmonitormeansthatportionoftheroofofapotroomwheregasesnotcapturedatthecellexitfromthepotroom.4.0Interferences.SameasSection4.0ofeitherMethod13AorMethod13B,withtheadditionofthefollowing:4.1MagneticFieldEffects.Anemometerreadingscanbeaffectedbypotroommagneticfieldeffects.Section6.1providesforminimizationofthisinterferencethroughpropershieldingorencasementofanemometercomponents.8885.0Safety.5.1Disclaimer.Thismethodmayinvolvehazardousmaterials,operations,andequipment.Thistestmethodmaynotaddressallofthesafetyproblemsassociatedwithitsuse.Itistheresponsibilityoftheuserofthistestmethodtoestablishappropriatesafetyandhealthpracticesandtodeterminetheapplicabilityofregulatorylimitationspriortoperformingthistestmethod.5.2CorrosiveReagents.SameasSection5.2ofeitherMethod13AorMethod13B.6.0EquipmentandSupplies.SameasSection6.0ofeitherMethod13AorMethod13B,asapplicable,withtheadditionofthefollowing:6.1VelocityMeasurementApparatus.6.1.1AnemometerSpecifications.Propelleranemometers,orequivalent.Eachanemometershallmeetthefollowingspecifications:6.1.1.1Itspropellershallbemadeofpolystyrene,orsimilarmaterialofuniformdensity.Toensureuniformityofperformanceamongpropellers,itisdesirablethatallpropellersbemadefromthesamemold.6.1.1.2Thepropellershallbeproperlybalanced,tooptimizeperformance.8896.1.1.3Whentheanemometerismountedhorizontally,itsthresholdvelocityshallnotexceed15m/min(50ft/min).6.1.1.4Themeasurementrangeoftheanemometershallextendtoatleast600m/min(2,000ft/min).6.1.1.5Theanemometershallbeabletowithstandprolongedexposuretodustyandcorrosiveenvironments;onewayofachievingthisistopurgethebearingsoftheanemometercontinuouslywithfilteredairduringoperation.6.1.1.6Allanemometercomponentsshallbeproperlyshieldedorencased,suchthattheperformanceoftheanemometerisuninfluencedbypotroommagneticfieldeffects.6.1.1.7Aknownrelationshipshallexistbetweentheelectricaloutputsignalfromtheanemometergeneratorandthepropellershaftrpm(seeSection10.2.1).Anemometershavingothertypesofoutputsignals(e.g.,optical)maybeused,subjecttotheapprovaloftheAdministrator.Ifothertypesofanemometersareused,theremustbeaknownrelationshipbetweenoutputsignalandshaftrpm(seeSection10.2.2).6.1.1.8Eachanemometershallbeequippedwithasuitablereadoutsystem(seeSection6.1.3).6.1.2AnemometerInstallationRequirements.8906.1.2.1Single,IsolatedPotroom.Iftheaffectedfacilityconsistsofasingle,isolatedpotroom(orpotroomsegment),installatleastoneanemometerforevery85m(280ft)ofroofmonitorlength.Ifthelengthoftheroofmonitordividedby85m(280ft)isnotawholenumber,roundthefractiontothenearestwholenumbertodeterminethenumberofanemometersneeded.Formonitorsthatarelessthan130m(430ft)inlength,useatleasttwoanemometers.Dividethemonitorcross-sectionintoasmanyequalareasasanemometers,andlocateananemometeratthecentroidofeachequalarea.SeeexceptioninSection6.1.2.3.6.1.2.2TwoorMorePotrooms.Iftheaffectedfacilityconsistsoftwoormorepotrooms(orpotroomsegments)ductedtoacommoncontroldevice,installanemometersineachpotroom(orsegment)thatcontainsasamplingmanifold.Installatleastoneanemometerforevery85m(280ft)ofroofmonitorlengthofthepotroom(orsegment).Ifthepotroom(orsegment)lengthdividedby85m(280ft)isnotawholenumber,roundthefractiontothenearestwholenumbertodeterminethenumberofanemometersneeded.Ifthepotroom(orsegment)lengthislessthan130m(430ft),useatleasttwoanemometers.Dividethepotroom(orsegment)monitorcross-sectionintoasmanyequalareasasanemometers,andlocateananemometer891atthecentroidofeachequalarea.SeeexceptioninSection6.1.2.3.6.1.2.3PlacementofAnemometerattheCenterofManifold.Atleas