Kuyaka kwa malasha m'malo opanga magetsi kumatulutsa zinyalala zolimba, monga phulusa la pansi ndi ntchentche, ndi mpweya wa flue womwe umatulutsidwa mumlengalenga. Zomera zambiri zimafunika kuchotsa mpweya wa SOx ku gasi wa flue pogwiritsa ntchito makina a flue gas desulfurization (FGD). Matekinoloje atatu otsogola a FGD omwe amagwiritsidwa ntchito ku US ndi kukolopa konyowa (85% yazikhazikiko), kupukuta kowuma (12%), ndi jakisoni wowuma wa sorbent (3%). Zonyowa zonyowa zimachotsa zoposa 90% za SOx, poyerekeza ndi zowuma zowuma, zomwe zimachotsa 80%. Nkhaniyi ikupereka matekinoloje apamwamba kwambiri otsuka madzi oipa omwe amapangidwa ndi madzi.Zithunzi za FGD.
Zoyambira Zonyowa za FGD
Ukadaulo wonyowa wa FGD uli ndi gawo lofanana la slurry reactor ndi gawo lotsitsa madzi olimba. Mitundu yosiyanasiyana ya ma absorbers yakhala ikugwiritsidwa ntchito, kuphatikizapo nsanja zodzaza ndi tray, venturi scrubbers, ndi zopopera zopopera mu gawo la reactor. Zosakaniza zimachepetsa mpweya wa acidic ndi slurry wa alkaline wa laimu, sodium hydroxide, kapena miyala yamchere. Pazifukwa zingapo zachuma, otsuka atsopano amakonda kugwiritsa ntchito miyala yamchere yamchere.
Pamene miyala yamchere imakhudzidwa ndi SOx mu kuchepetsa mikhalidwe ya absorber, SO 2 (chigawo chachikulu cha SOx) chimasandulika kukhala sulfite, ndipo slurry wolemera mu calcium sulfite amapangidwa. Machitidwe oyambirira a FGD (omwe amatchedwa kuti oxidation achilengedwe kapena machitidwe oletsa okosijeni) adatulutsa calcium sulfite ndi mankhwala. ZatsopanoZithunzi za FGDgwiritsani ntchito riyakitala ya okosijeni momwe calcium sulfite slurry imasinthidwa kukhala calcium sulfate (gypsum); izi zimatchedwa limestone force oxidation (LSFO) FGD systems.
Makina amakono a LSFO FGD amagwiritsa ntchito makina opopera omwe ali ndi cholumikizira cha okosijeni m'munsi (Chithunzi 1) kapena makina opangira jeti. Mu lililonse mpweya odzipereka mu laimu slurry pansi anoxic zinthu; slurry ndiye amadutsa aerobic riyakitala kapena reaction zone, kumene sulfite ndi n'kukhala sulphate, ndi gypsum precipitates. Nthawi yotsekera ma Hydraulic mu riyakitala ya okosijeni ndi pafupifupi mphindi 20.
1. Utsi mzati limestone kukakamiza oxidation (LSFO) FGD dongosolo. Mu LSFO scrubber slurry amadutsa ku reactor, komwe mpweya umawonjezeredwa kukakamiza oxidation wa sulfite kukhala sulfate. Oxidation iyi ikuwoneka kuti imasintha selenite kukhala selenate, zomwe zimapangitsa kuti pakhale zovuta zachipatala. Chitsime: CH2M HILL
Makinawa nthawi zambiri amagwira ntchito ndi zolimba zoyimitsidwa za 14% mpaka 18%. Zolimba zoyimitsidwa zimakhala zolimba komanso zolimba za gypsum, phulusa la ntchentche, ndi zinthu zoziziritsa kukhosi zomwe zimayambitsidwa ndi mwala wa laimu. Zolimba zikafika pamtunda wapamwamba, slurry amatsukidwa. Makina ambiri a LSFO FGD amagwiritsa ntchito makina olekanitsa zolimba ndi kuchotsera madzi kuti alekanitse gypsum ndi zolimba zina ndi madzi oyeretsera (Chithunzi 2).
2. FGD purge gypsum dewatering system. Mu mawonekedwe a gypsum dewatering system particles mu purge amagawidwa, kapena kulekanitsidwa, kukhala tizigawo ta coarse ndi zabwino. Fine particles amasiyanitsidwa mu kusefukira kwa hydroclone kutulutsa underflow yomwe imakhala makamaka ndi makhiristo akuluakulu a gypsum (ogulitsa omwe angathe kugulitsidwa) omwe amatha kuthiridwa ndi chinyezi chochepa chokhala ndi vacuum lamba dewatering system. Chitsime: CH2M HILL
Makina ena a FGD amagwiritsa ntchito zokhuthala mphamvu yokoka kapena maiwe okhazikika kuti agawidwe zolimba ndi kuthira madzi, ndipo ena amagwiritsa ntchito ma centrifuge kapena ma rotary vacuum dewatering system, koma makina atsopano ambiri amagwiritsa ntchito ma hydroclones ndi malamba owumitsa. Ena atha kugwiritsa ntchito ma hydroclones awiri motsatizana kuti awonjezere kuchotsedwa kwa zolimba m'dongosolo la dewatering. Gawo lina la kusefukira kwa hydroclone likhoza kubwezeredwa ku dongosolo la FGD kuti muchepetse kuyenda kwa madzi otayira.
Kuyeretsa kumatha kuyambikanso pakakhala kuchuluka kwa ma chloride mu FGD slurry, chifukwa cha malire omwe amakhazikitsidwa ndi kukana kwa dzimbiri kwa zida zomangira za FGD system.
Makhalidwe a FGD Wastewater
Zosintha zambiri zimakhudza mapangidwe amadzi onyansa a FGD, monga kupanga malasha ndi miyala yamchere, mtundu wa scrubber, ndi gypsum-dewatering system yomwe imagwiritsidwa ntchito. Malasha amathandizira mpweya wa acidic - monga ma chlorides, fluorides, ndi sulfate - komanso zitsulo zosakhazikika, kuphatikiza arsenic, mercury, selenium, boron, cadmium, ndi zinki. Mwala wa laimu umathandizira chitsulo ndi aluminiyamu (kuchokera ku mchere wadothi) kupita kumadzi onyansa a FGD. Mwala wa laimu nthawi zambiri umaphwanyidwa mu mphero yonyowa, ndipo kukokoloka ndi dzimbiri kwa mipirayo kumathandizira chitsulo pamatope a laimu. Dongo limakonda kupereka chindapusa cha inert, chomwe ndi chimodzi mwazifukwa zomwe madzi oyipa amachotsedwa ku scrubber.
Kuchokera: Thomas E. Higgins, PhD, PE; A. Thomas Sandy, PE; ndi Silas W. Givens, PE.
Imelo:[imelo yotetezedwa]
Nthawi yotumiza: Aug-04-2018