Kev sib xyaw ntawm cov thee hauv cov chaw tsim hluav taws xob tsim cov khoom pov tseg, xws li hauv qab thiab ya tshauv, thiab cov pa taws uas tawm mus rau qhov chaw. Ntau cov nroj tsuag yuav tsum tau tshem tawm SOx emissions los ntawm flue gas siv flue gas desulfurization (FGD) systems. Peb lub FGD thev naus laus zis siv hauv Asmeskas yog kev txhuam ntub dej (85% ntawm kev teeb tsa), kev txhuam kom qhuav (12%), thiab kev txhaj tshuaj sorbent qhuav (3%). Cov ntxhua khaub ncaws ntub dej feem ntau tshem tawm ntau dua 90% ntawm SOx, piv rau cov ntxhua khaub ncaws qhuav, uas tshem tawm 80%. Kab lus no nthuav tawm cov thev naus laus zis niaj hnub rau kev kho cov dej khib nyiab uas tsim los ntawm ntub dejFGD systems.
Wet FGD Basics
Cov technologies ntub dej FGD muaj nyob rau hauv ib qho ntawm cov slurry reactor seem thiab cov khib nyiab dewatering seem. Ntau hom absorbers tau raug siv, suav nrog ntim thiab cov tais yees, venturi scrubbers, thiab tshuaj tsuag tshuaj tsuag hauv seem reactor. Cov absorbers neutralize cov kua qaub gasses nrog alkaline slurry ntawm txiv qaub, sodium hydroxide, los yog limestone. Rau ntau qhov laj thawj ntawm kev lag luam, cov tshuab tshiab tshiab nyiam siv limestone slurry.
Thaum limestone reacts nrog SOx nyob rau hauv lub txo tej yam kev mob ntawm lub absorber, SO 2 (qhov tseem ceeb ntawm SOx) hloov mus rau hauv sulfite, thiab ib tug slurry nplua nuj nyob rau hauv calcium sulfite yog tsim. Yav dhau los FGD systems (hu ua ntuj oxidation lossis inhibited oxidation systems) tsim cov calcium sulfite los ntawm cov khoom. Tshiab duaFGD systemsntiav cov oxidation reactor uas cov calcium sulfite slurry hloov mus rau calcium sulfate (gypsum); Cov no yog hu ua limestone yuam oxidation (LSFO) FGD systems.
Cov niaj hnub niaj hnub LSFO FGD tshuab siv ob qho tshuaj tsuag ntauwd absorber nrog ib qho oxidation reactor nyob rau hauv lub hauv paus (Daim duab 1) los yog lub dav hlau bubbler system. Nyob rau hauv txhua lub roj yog absorbed nyob rau hauv ib tug limestone slurry nyob rau hauv anoxic tej yam kev mob; cov slurry ces dhau mus rau aerobic reactor los yog cov tshuaj tiv thaiv cheeb tsam, qhov twg sulfite hloov mus rau sulfate, thiab gypsum precipitates. Hydraulic kaw lub sij hawm nyob rau hauv lub oxidation reactor yog hais txog 20 feeb.
1. Txau kab limestone yuam oxidation (LSFO) FGD system. Nyob rau hauv ib qho LSFO scrubber slurry hla mus rau lub reactor, qhov twg huab cua ntxiv rau quab yuam oxidation ntawm sulfite rau sulfate. Qhov no oxidation zoo li hloov selenite rau selenate, ua rau tom qab kev kho mob nyuaj. Source: CH2M HILL
Cov tshuab no feem ntau ua haujlwm nrog cov khoom raug tshem tawm ntawm 14% mus rau 18%. Cov khib nyiab pov tseg muaj cov khoom zoo thiab ntxhib gypsum, ya tshauv, thiab cov khoom siv inert qhia nrog limestone. Thaum cov khib nyiab ncav cuag qhov siab tshaj, slurry yog purged. Feem ntau LSFO FGD tshuab siv cov khoom sib cais thiab dewatering tshuab cais gypsum thiab lwm cov khib nyiab los ntawm cov dej huv (Daim duab 2).
2. FGD ntxuav gypsum dewatering system. Nyob rau hauv ib tug raug gypsum dewatering system hais nyob rau hauv lub purge yog cais, los yog sib cais, mus rau hauv ntxhib thiab nplua feem. Cov khoom zoo raug muab cais tawm hauv cov dej ntws los ntawm hydroclone los tsim cov dej hauv qab uas muaj feem ntau ntawm cov gypsum crystals loj (rau kev muag khoom) uas tuaj yeem dewatered kom tsis muaj dej noo nrog lub tshuab nqus tsev dewatering system. Source: CH2M HILL
Qee lub tshuab FGD siv lub ntiajteb txawj nqus thickeners los yog teeb tsa lub pas dej rau kev faib cov khib nyiab thiab dewatering, thiab qee qhov siv cov centrifuges los yog lub tshuab nqus tsev nqus dej, tab sis feem ntau cov tshuab tshiab siv hydroclones thiab nqus plua plav. Qee tus tuaj yeem siv ob lub hydroclones hauv koob txhawm rau txhawm rau tshem tawm cov khib nyiab hauv cov dej dewatering. Ib feem ntawm hydroclone overflow yuav raug xa rov qab mus rau FGD system kom txo cov dej khib nyiab.
Purging kuj tseem yuav pib thaum muaj cov tshuaj chlorides hauv FGD slurry, tsim nyog los ntawm kev txwv los ntawm kev tiv thaiv corrosion ntawm FGD system cov khoom siv.
FGD Cov yam ntxwv dej khib nyiab
Ntau qhov sib txawv cuam tshuam rau FGD cov dej khib nyiab, xws li cov thee thiab limestone muaj pes tsawg leeg, hom scrubber, thiab gypsum-dewatering system siv. Coal pab txhawb cov kua qaub - xws li chlorides, fluorides, thiab sulfate - nrog rau cov hlau tsis muaj zog, suav nrog arsenic, mercury, selenium, boron, cadmium, thiab zinc. Cov limestone txhawb nqa hlau thiab txhuas (los ntawm av nplaum ntxhia) rau FGD cov dej khib nyiab. Limestone feem ntau yog pulverized nyob rau hauv ib lub pob zeb ntub dej, thiab kev yaig thiab corrosion ntawm cov khoom ua rau cov hlau rau cov limestone slurry. Cov av nplaum zoo li ua rau kev nplua nyiaj tsis zoo, uas yog ib qho laj thawj uas cov dej khib nyiab purged los ntawm lub tshuab ntxhua khaub ncaws.
Los ntawm: Thomas E. Higgins, PhD, PE; A. Thomas Sandy, PE; thiab Silas W. Givens, PE.
Email:[email tiv thaiv]
Post lub sij hawm: Aug-04-2018