Ukushiswa kwamalahle ezindaweni zokuphehla ugesi kukhiqiza imfucuza eqinile, efana nomlotha ophansi kanye ne-fly ash, kanye negesi ephumayo ekhishelwa emkhathini. Izitshalo eziningi ziyadingeka ukuze zisuse ukukhishwa kwe-SOx kugesi we-flue usebenzisa izinhlelo ze-flue gas desulfurization (FGD). Ubuchwepheshe obuthathu obuphambili be-FGD obusetshenziswa e-US ukukhuhla okumanzi (85% okufakwayo), ukukhuhla okomile (12%), kanye nomjovo owomile we-sorbent (3%). Izikhuhla ezimanzi ngokuvamile zisusa ngaphezu kwe-90% ye-SOx, uma kuqhathaniswa nezikhuhla ezomile, ezisusa u-80%. Lesi sihloko sethula ubuchwepheshe besimanje bokugeza amanzi angcolile akhiqizwa amanzi.Amasistimu we-FGD.
Izisekelo ezimanzi ze-FGD
Ubuchwepheshe be-FGD obumanzi bufana nesigaba se-slurry reactor kanye nesigaba sokususa amanzi okuqinile. Izinhlobo ezihlukahlukene zokudonsa zisetshenzisiwe, kufaka phakathi imibhoshongo epakishiwe kanye nethreyi, ama-venturi scrubbers, kanye ne-spray scrubbers esigabeni se-reactor. Ama-absorber anciphisa amagesi ane-asidi nge-alkaline slurry ye-lime, i-sodium hydroxide, noma i-limestone. Ngenxa yezizathu eziningi zezomnotho, ama-scrubber amasha avame ukusebenzisa i-limestone slurry.
Lapho i-limestone isabela nge-SOx ezimweni zokunciphisa i-absorber, i-SO 2 (ingxenye enkulu ye-SOx) iguqulwa ibe yi-sulfite, futhi i-slurry ecebile nge-calcium sulfite ikhiqizwa. Ngaphambilini amasistimu e-FGD (okubizwa ngokuthi i-oxidation yemvelo noma amasistimu e-oxidation avinjelwe) akhiqize umkhiqizo we-calcium sulfite. OkushaAmasistimu we-FGDsebenzisa i-reactor oxidation lapho i-calcium sulfite slurry iguqulwa ibe yi-calcium sulfate (gypsum); lezi zibizwa ngokuthi i-limestone force oxidation (LSFO) FGD systems.
Amasistimu ajwayelekile esimanje e-LSFO FGD asebenzisa isifutho sombhoshongo wokudonsa esine-integrated oxidation reactor esisekelweni (Umfanekiso 1) noma isistimu yebhamuza yejethi. Kulelo nalelo igesi imuncwa ku-limestone slurry ngaphansi kwezimo ezinoxic; i-slurry ibe isidlulela ku-reactor ye-aerobic noma indawo yokusabela, lapho i-sulfite iguqulwa ibe yi-sulfate, futhi i-gypsum precipitates. Isikhathi sokuvalelwa kwe-hydraulic ku-reactor ye-oxidation cishe imizuzu engama-20.
1. Futha ikholomu ye-limestone ephoqelelwe nge-oxidation (LSFO) FGD system. Ku-LSFO scrubber slurry kudlulela ku-reactor, lapho umoya wengezwa khona ukuze uphoqe ukukhishwa kwe-sulfite ku-sulfate. Le oxidation ibonakala iguqula i-selenate ibe i-selenate, okuholela ebunzimeni bokwelashwa kamuva. Umthombo: CH2M HILL
Lezi zinhlelo ngokuvamile zisebenza ngezinto eziqinile ezimisiwe ze-14% kuya ku-18%. Izinto eziqinile ezilengisiwe zihlanganisa izinto eziqinile neziqinile ze-gypsum, umlotha wempukane, nezinto ezingasebenzi okwethulwa nge-limestone. Lapho izinto eziqinile zifinyelela umkhawulo ophezulu, i-slurry iyahlanzwa. Amasistimu amaningi e-LSFO FGD asebenzisa imishini yokuhlukanisa izinto eziqinile kanye nezinhlelo zokususa amanzi ukuze ahlukanise i-gypsum nezinye izinto eziqinile emanzini okuhlanza (Umfanekiso 2).
2. I-FGD ihlanza i-gypsum dewatering system. Ohlelweni olujwayelekile lokususa amanzi lwe-gypsum izinhlayiya ekuhlanzeni zihlukaniswa, noma zihlukaniswe, zibe izingxenyana ezimahhadla nezicolekileyo. Izinhlayiya ezinhle zihlukaniswa ekuchichimeni okuvela ku-hydroclone ukuze kukhiqizwe ukugeleza okungaphansi okuqukethe ikakhulukazi amakristalu amakhulu e-gypsum (okungase athengiswe) okungase kuncishiswe kumswakama ophansi nge-vacuum belt dewatering system. Umthombo: CH2M HILL
Amanye amasistimu e-FGD asebenzisa ama-gravity thickeners noma amachibi okumisa ukuze kuhlukaniswe izinto eziqinile kanye nokuqeda amanzi, futhi amanye asebenzisa ama-centrifuge noma amasistimu okuqeda amanzi emigqomo ejikelezayo, kodwa amasistimu amaningi amasha asebenzisa ama-hydroclone namabhande e-vacuum. Abanye bangasebenzisa ama-hydroclone amabili ochungechungeni ukwandisa ukukhishwa okuqinile ohlelweni lokukhipha amanzi. Ingxenye yokuchichima kwe-hydroclone ingase ibuyiselwe ohlelweni lwe-FGD ukuze kuncishiswe ukugeleza kwamanzi angcolile.
Ukuhlanzwa kungase futhi kuqaliswe uma kukhona ukunqwabelana kwama-chloride odaka lwe-FGD, okudingeke ngemikhawulo ebekwe ukumelana nokugqwala kwezinto zokwakha zesistimu ye-FGD.
Izimpawu ze-FGD Wastewater
Okuguquguqukayo okuningi kuthinta ukwakheka kwamanzi angcolile e-FGD, njengokwakheka kwamalahle ne-limestone, uhlobo lwe-scrubber, kanye nesistimu yokukhipha amanzi e-gypsum esetshenzisiwe. Amalahle anikela ngamagesi ane-asidi - njengama-chlorides, i-fluorides, ne-sulfate - kanye nezinsimbi eziguquguqukayo, okuhlanganisa i-arsenic, i-mercury, i-selenium, i-boron, i-cadmium, ne-zinc. I-limestone inikela ngensimbi ne-aluminium (kusuka kumaminerali obumba) ukuya emanzini angcolile e-FGD. I-limestone ivamise ukugaywa ebholeni elimanzi, futhi ukuguguleka nokugqwala kwamabhola kufaka insimbi odongeni lwe-limestone. Ubumba luvame ukufaka inhlawulo engasebenzi, okungesinye sezizathu zokuthi amanzi angcolile ahlanzwe ku-scrubber.
From: Thomas E. Higgins, PhD, PE; A. Thomas Sandy, PE; kanye noSilas W. Givens, PE.
I-imeyili:[i-imeyili ivikelwe]
Isikhathi sokuthumela: Aug-04-2018