炼油厂电脱盐换热器腐蚀失效分析

,(,730060):,:2;pH:;;;:TQ050.9:B:100023738(2008)0120081203CorrosionAnalysisofHeatExchangerinElectricDesalterofDelayCookingUnitWANGYing2li,WANGJian2sheng(LanzhouPetroleumandChemicalCompanyCorporation,Lanzhou730060,China)Abstract:Byobservingthecorrosiveappearanceofthedisabledexchange2heater,analyzingthechemicalcomponentofcorrosionproductandwaterqualityfortheelectricdesalter,andinvestigatingthetechnicalconditionsoftheexchange2heater,thecorrosionreasonoftheexchange2heaterusedforelectricdesalterinadelaycookingunit.Theresultsshowthatthefailureoftheoutertubesurfaceofexchange2heaterisinducedbytheunder2depositcorrosionresultingfromgatheringofcalcium,bariumandbedloadinfreshwateronthetubesurface.Thefailureoftheexchange2heatertubeinnersurfaceiscausedbyelectrochemicalcorrosioninthedesaltingwaterhavinglowerpHvalue.Keywords:delaycookingunit;electricdesalter;heatexchanger;corrosion02106ta-1FULA,610mgg-1KOH,1200mgkg-1[1]6,,,36,,40,,130,80,10,,11.1232;252(),,,,1(),,,,,,2(),,1.2,Ffx2832120081MaterialsforMechanicalEngineeringVol.32No.1Jan.2008:2007022:2007011:1974-1ig.1Corrosiveappearanceoechangerheater12Fig.2Corrosiveappearenceofentryandofexchanger2heater1,101(/%)Tab.1Chemicalcompositionofsamples(mass/%)CSSiPMn100.070.140.0350.170.370.0350.0350.650.080.0310.200.0320.081.3,pH6.91,,pH7.94,,pH5.31,;Cl-N,Ca2+SO2-4S2-,Fe3+1009002(mgL-1)Tab.2AnalyseofmaterqualityCl-Fe3+Ca2+SO2-4S2-N8.490.0565.7731.4435.620.238.650.7157.12---15.2124.586385.2---1.4EDS2100X,3,10,,,3Tab.3AnalyseofcompositionofcorrosionproductFeBaCOSSiAlCaP/%54.8922.947.455.726.351.130.530.520.47/%40.716.9225.7014.828.201.660.820.530.632.1Ca2+Ba2+SO2-4,Ca2+Ba2+SO2-4CaSO4BaSO4;HCO-3Ca(HCO3)2Ba(HCO3)2;2CO2-3CaCO3BaCO3,CaSO4BaSO4CaCO3BaCO3,,,,,Al2O3SiO2,[2],,,,,[3],,,,,2[4],,,,,2.2,,,pHpH,2H2O+4e+O2=4OH-,2H++2e=H2,,[5]3(1),,2(2)(3)8,:22;,pH,(4)1828,2a,:[1],,,.[J].,2006,25(3):343-346.[2],,,.6[J].,2006,19(6):71-72.[3],./[J].,2001,20(12):40-60.[4],.[M].:,1999:122-132.[5].[M].:,1990:50-52.(78)(2),SiO23h50%300rmin-120(3)SiO2,,:[1],,,.[J].,2003,22(6):,45-46.[2],.[J].,2002,14(4):32-35.[3]∗vaMak,ZsuzsaSenkr,JnosKristf,etal.Surfacemodi2ficationofmechanochemicallyactivatedkaolinitesbyselectiveleaching[J].JournalofColloidandInterfaceScience,2006,294(2):362-370.[4]LinHai,KangWeigang,HuangMan,etal.Mechanochemicalmodificationandapplicationoftwo2dimensionsericiteflakynano2materials[J].JournalofUniversityofScienceandTech2nologyBeijing,2004,26(6):627-630.[5]LiZ,ShenSY,PengJR,etal.Mechanochemicalmodifica2tionofwollastoniteanditsapplicationtopolypropylene[J].KeyEngineeringMaterials,2003,249:409-412.[6],,.[J].,2003,27(2):294-297.[7]AhmedNasser,GarrisonSposito,MarcosA.Cheney.Mech2anochemicaldegradationof2,42Dadsorbedonsyntheticbir2nessite[J].ColloidsandSurfacesA:PhysicochemicalandEn2gineeringAspects,2000,163(2/3):117-123.[8],,,.[J].,1998,7(2):62-64.[9],.[J].,2004,20(3):335-338.(80),(a)(b)4SEM500Fig.4Observationofpropagatingregion(2)304107107,(3),:[1].[M].:,1995.[2],.[J].,2004,25(4):12-16.[3],.[J].,2005,27(3):388-394.[4].[J].,2002,24()88338,:1:1-.