Kev hlawv thee hauv cov chaw tsim hluav taws xob tsim cov khib nyiab khov, xws li cov tshauv hauv qab thiab cov tshauv ya, thiab cov pa roj uas tawm mus rau huab cua. Ntau lub Hoobkas yuav tsum tau tshem tawm cov pa roj SOx los ntawm cov pa roj siv cov tshuab flue gas desulfurization (FGD). Peb txoj kev siv tshuab FGD ua ntej siv hauv Tebchaws Meskas yog kev txhuam ntub (85% ntawm cov chaw teeb tsa), kev txhuam qhuav (12%), thiab kev txhaj tshuaj nqus qhuav (3%). Cov tshuab txhuam ntub feem ntau tshem tawm ntau dua 90% ntawm SOx, piv rau cov tshuab txhuam qhuav, uas tshem tawm 80%. Tsab xov xwm no qhia txog cov thev naus laus zis tshiab rau kev kho cov dej khib nyiab uas tsim los ntawm kev txhuam ntubCov txheej txheem FGD.
Cov Ntsiab Lus Tseem Ceeb ntawm Wet FGD
Cov thev naus laus zis FGD ntub muaj qhov sib xws ntawm cov khoom siv slurry reactor thiab cov khoom siv dewatering. Ntau hom absorbers tau siv, suav nrog cov packed thiab tray towers, venturi scrubbers, thiab spray scrubbers hauv reactor seem. Cov absorbers neutralize cov acidic gasses nrog cov alkaline slurry ntawm lime, sodium hydroxide, lossis limestone. Vim muaj ntau yam laj thawj nyiaj txiag, cov scrubbers tshiab dua feem ntau siv limestone slurry.
Thaum limestone tshuaj tiv thaiv nrog SOx nyob rau hauv cov xwm txheej txo qis ntawm lub absorber, SO2 (qhov tseem ceeb ntawm SOx) raug hloov mus ua sulfite, thiab cov slurry nplua nuj nyob rau hauv calcium sulfite raug tsim tawm. Cov txheej txheem FGD ua ntej (hu ua natural oxidation lossis inhibited oxidation systems) tsim cov calcium sulfite by-product. Tshiab duaCov txheej txheem FGDsiv lub tshuab oxidation uas cov calcium sulfite slurry hloov mus ua calcium sulfate (gypsum); cov no hu ua limestone forced oxidation (LSFO) FGD systems.
Cov txheej txheem LSFO FGD niaj hnub no feem ntau siv lub tshuab nqus dej nrog lub tshuab ua kom oxidation hauv lub hauv paus (Daim Duab 1) lossis lub tshuab jet bubbler. Hauv txhua qhov, cov pa roj raug nqus rau hauv cov limestone slurry nyob rau hauv cov xwm txheej anoxic; cov slurry ces dhau mus rau lub tshuab ua kom aerobic lossis thaj chaw ua haujlwm, qhov twg sulfite hloov pauv mus ua sulfate, thiab gypsum precipitates. Lub sijhawm tswj hydraulic hauv lub tshuab ua kom oxidation yog li 20 feeb.
1. Lub tshuab txau pob zeb limestone forced oxidation (LSFO) FGD system. Hauv lub tshuab LSFO scrubber, cov slurry hla mus rau lub reactor, qhov twg cua raug ntxiv los yuam kom oxidation ntawm sulfite mus rau sulfate. Qhov oxidation no zoo li hloov selenite mus rau selenate, ua rau muaj teeb meem kho tom qab. Qhov chaw: CH2M HILL
Cov kab ke no feem ntau ua haujlwm nrog cov khoom khov uas raug tshem tawm ntawm 14% txog 18%. Cov khoom khov uas raug tshem tawm muaj cov khoom khov gypsum zoo thiab ntxhib, cov tshauv ya, thiab cov khoom tsis muaj zog uas tau qhia nrog cov limestone. Thaum cov khoom khov mus txog qhov siab tshaj plaws, cov slurry raug ntxuav tawm. Feem ntau cov kab ke LSFO FGD siv cov tshuab sib cais cov khoom khov thiab cov tshuab dewatering los cais cov gypsum thiab lwm cov khoom khov ntawm cov dej ntxuav (Daim Duab 2).
2. FGD purge gypsum dewatering system. Hauv ib qho system dewatering gypsum feem ntau, cov khoom me me hauv purge raug cais, lossis sib cais, ua cov khoom loj thiab cov khoom me me. Cov khoom me me raug sib cais hauv cov dej ntws los ntawm hydroclone los tsim cov dej ntws uas feem ntau muaj cov gypsum loj (rau kev muag khoom) uas tuaj yeem dewatered mus rau qhov dej noo tsawg nrog lub tshuab nqus tsev dewatering system. Qhov chaw: CH2M HILL
Qee lub tshuab FGD siv cov khoom siv gravity thickeners lossis cov pas dej settling rau kev faib cov khoom khov thiab dewatering, thiab qee qhov siv centrifuges lossis rotary vacuum drum dewatering systems, tab sis feem ntau cov tshuab tshiab siv hydroclones thiab vacuum belts. Qee qhov yuav siv ob lub hydroclones ua ke kom nce cov khoom khov tshem tawm hauv lub tshuab dewatering. Ib feem ntawm cov hydroclone overflow yuav raug xa rov qab mus rau lub tshuab FGD kom txo cov dej khib nyiab ntws.
Kev ntxuav kuj tseem yuav pib thaum muaj cov chlorides sib sau ua ke hauv cov dej FGD, uas yog vim muaj kev txwv los ntawm kev tiv thaiv xeb ntawm cov ntaub ntawv tsim kho ntawm FGD system.
Cov yam ntxwv ntawm cov dej khib nyiab FGD
Muaj ntau yam uas cuam tshuam rau cov dej khib nyiab FGD, xws li cov thee thiab limestone, hom scrubber, thiab cov gypsum-dewatering system siv. Thee ua rau muaj cov pa roj acidic - xws li chlorides, fluorides, thiab sulfate - nrog rau cov hlau uas tsis yooj yim hloov pauv, suav nrog arsenic, mercury, selenium, boron, cadmium, thiab zinc. Cov limestone ua rau muaj hlau thiab txhuas (los ntawm cov av nplaum) rau cov dej khib nyiab FGD. Limestone feem ntau yog crushed hauv lub tshuab sib tsoo pob ntub, thiab kev yaig thiab xeb ntawm cov pob ua rau muaj hlau rau cov limestone slurry. Cov av nplaum feem ntau ua rau muaj cov inert fines, uas yog ib qho ntawm cov laj thawj uas cov dej khib nyiab raug purged ntawm scrubber.
Los ntawm: Thomas E. Higgins, PhD, PE; A. Thomas Sandy, PE; thiab Silas W. Givens, PE.
Email: caroline@rbsic-sisic.com
Lub sijhawm tshaj tawm: Lub Yim Hli-04-2018