7,635,449Method of inhibiting corrosion in hot wat

(87of2746)UnitedStatesPatent7,635,449Bailey,III,etal.December22,2009MethodofinhibitingcorrosioninhotwatersystemsAbstractThisinventionconcernsmethodsandapparatusformeasuringoxidationreductionpotentialsofwaterinahotwatersystematsystemtemperatureandpressureandmethodsofusingthemeasuredoxidation-reductionpotentialtomonitorandcontroltheadditionofoxygenscavengersoroxygentothesysteminordertomaintaineffectivecorrosioninhibitingconcentrationsoftheoxygenscavengersordissolvedoxygeninthesystem.Inventors:Bailey,III;BruceR.(Tuttle,OK),Hicks;PeterD.(Aurora,IL)Assignee:NalcoCompany(Naperville,IL)Appl.No.:11/403,420Filed:April12,2006RelatedU.S.PatentDocumentsApplicationNumberFilingDatePatentNumberIssueDateTDTD10718424Nov.,2003TDTDCurrentU.S.Class:422/11;422/14CurrentInternationalClass:C23F11/00(20060101)FieldofSearch:252/390ReferencesCited[ReferencedBy]U.S.PatentDocuments4269717May1981Slovinsky4574071March1986deSilvaetal.4775005October1988Beyeretal.5236845August1993Pierceetal.5268092December1993Eden5332494July1994Edenetal.5342510August1994Edenetal.6391256May2002Moonetal.6402984June2002Nakajimaetal.2003/0004681January2003Fandrichetal.ForeignPatentDocuments2003254503Sep.,2003JPWO0159535Aug.,2001WOOtherReferencesUchino,Yujirou,etal.StudyonthePracticalApplicationofaMethodforCorrsionPotentialMeasurementinaWaterQualityMonitoringSystemUsedDuringCombinedWaterTreatment.PowerPlantChemistry,2001,3(9),pp.511-517.citedbyexaminer.ShaneFiler,PowerPlantChemistryMeasurementAdvancements:OxidationReductionPotential,UltrapureWater,pp.53-62,Nov.1998.citedbyother.T.Kh.Margulova,I.V.Zubov,L.V.Kuz'micheva,L.M.Zitivilova,P.N.Nazarenko,Conditionsofdosingoxygenandhydrogenperoxideintothecondensateofpowerunitsofsupercriticalparameters(Abstract),Teploenergetia,1977.citedbyother.Buecker,B..,WaterTreatment:theContinuingBattleAgainstFAC,PowerEngineering,vol.106,No.9,Sep.2002,pp.32-34.citedbyother.Dedekind,Irmaetal.,OxygenatedFeedwaterTreatmentattheWorld'sLargestFossilFiredPowerPlant--BewarethePitfalls--,PowerPlantChemistry,vol.3,No.11,Nov.2001.citedbyother.Haag,J.etal.,On-LineMeasurementofRedoxandCorrosionPotentialsinWaterforPWRSteamGenerators,Kraftwerkstechnik,KraftwerkstechnikGMbH.,Essen,DE,vol.70,No.3,Mar.1,1990,pp.236-241.citedbyother.Niedrach,LeonardW.,ElectrodesforPotentialMeasurementsinAqueousSystemsatHighTemperaturesandPressures,AngewandteChemie--InternationalEdition,vol.26,No.3,Mar.1987,pp.161-169.citedbyother.ThomasH.PikeandEmeryLange,AnImprovedMethodforMonitoringLowConcentrationsofVolatileOxygenScavengers,IWC,Jan.2008,pp.64-67.citedbyother.BarryDooley,DigbyMacdonaldandBarryC.Syrett,ORP--TheRealStoryforFossilPlants,PowerPlantChemistry2003,5(1),pp.5-15.citedbyother.PrimaryExaminer:McKane;ElizabethLAttorney,AgentorFirm:DiMattia;PeterA.Martin;MichaelB.ParentCaseTextCROSSREFERENCETORELATEDAPPLICATIONSThisapplicationisacontinuationapplicationofU.S.patentapplicationSer.No.10/718,424,whichwasfiledonNov.10,2003nowabandoned.ClaimsTheinventionclaimedis:1.Amethodofmaintaininganeffectivecorrosion-inhibitingamountofoxygenscavengeroroxygeninahotwatersystemcomprising(i)determiningrangeofoxidation-reductionpotentialsforeffectivecorrosioninhibitionforthesystematsystemtemperature,pressureandpH;(ii)measuringtheoxidation-reductionpotentialofthefeedwaterinthesystematoperatingtemperatureandpressure;and(iii)addingoxygenoroxygenscavengertothesystemtomaintaintheoxidation-reductionpotentialofthefeedwaterinthesystemwithinthepredeterminedrangeofoxidation-reductionpotentials.2.Themethodofclaim1whereinthehotwatersystemisanindustrialboilersystem.3.Themethodofclaim2whereinanoxygenscavengerisaddedtothehotwatersystem.4.Themethodofclaim3whereintheoxygenscavengerisselectedfromthegroupconsistingofhydrazine,sodiumsulfite,carbohyrazide,N,N-diethyihydroxylamine,hydroquinone,erythorbate,methylethylketoxime,hydroxylamine,andgallicacid.5.Amethodofinhibitingcorrosionofthemetalsurfacesofahotwatersystemcomprising(i)addinganeffectivecorrosioninhibitingamountofoxygenoroneormoreoxygenscavengerstothesystem;(ii)measuringtheoxidation-reductionpotentialofthefeedwaterinthesystematoperatingtemperatureandpressure;and(iii)addingoxygenoroxygenscavengertothesystemtomaintaintheeffectiveamountofoxygenoroxygenscavengersinthesystembasedonthemeasuredoxidation-reductionpotentialofthewater.6.Themethodofclaim5whereinthemeasuringofoxidation-reductionpotentialsandadditionofoxygenoroxygenscavengersisperformedcontinuously.7.Themethodofclaim5whereinthemeasuringofoxidation-reductionpotentialsandadditionofoxygenoroxygenscavengersisperformedintermittently.8.Amethodofinhibitingcorrosionofthemetalsurfacesofahotwatersystemcomprising(i)determiningrangeofoxidation-reductionpotentialsforeffectivecorrosioninhibitionforthesystematsystemtemperature,pressureandpH;(ii)addingoxygenoroneormoreoxygenscavengerstothesystemtobringthesystemoxidation-reductionpotentialwithinthepredeterminedrange;(iii)continuouslyorintermittentlymeasuringtheoxidation-reductionpotentialofthefeedwaterinthesystematoperatingtemperatureandpressure;and(iv)a