Kupisa kwemarasha munzvimbo dzekugadzira magetsi kunoburitsa tsvina yakasimba, senge pasi nedota renhunzi, uye gasi reflue rinoburitswa mumhepo. Zvidyarwa zvakawanda zvinotarisirwa kubvisa SOx emissions kubva kuflue gasi uchishandisa flue gas desulfurization (FGD) masisitimu. Iwo matatu anotungamira FGD matekinoroji anoshandiswa muUS kukwesha mvura (85% yezvimisikidzo), kukwesha kwakaoma (12%), uye yakaoma sorbent jekiseni (3%). Wet scrubbers inowanzobvisa zvinopfuura 90% zveSOx, zvichienzaniswa nemafuta akaoma, anobvisa 80%. Ichi chinyorwa chinopa matekinoroji echizvino-zvino ekurapa mvura yetsvina inogadzirwa nekunyorova.FGD masisitimu.
Wet FGD Basics
Wet FGD matekinoroji ane akafanana slurry reactor chikamu uye solids dewatering chikamu. Mhando dzakasiyana-siyana dzekunyudza dzakashandiswa, kusanganisira dzakarongedzwa uye shongwe dzetireyi, venturi scrubbers, uye spray scrubbers muchikamu chereactor. Izvo zvinotora zvinoderedza gasi rine acidic nealkaline slurry yeraimu, sodium hydroxide, kana limestone. Nokuda kwezvikonzero zvakawanda zvehupfumi, vatsva vanochera vanowanzoshandisa limestone slurry.
Apo limestone inopindirana neSOx mumamiriro ekuderedza emushonga, SO 2 (iyo chikamu chikuru cheSOx) inoshandurwa kuva sulfite, uye slurry yakawanda mu calcium sulfite inogadzirwa. Kare maFGD masisitimu (anonzi akasikwa oxidation kana inhibited oxidation masisitimu) akagadzira calcium sulfite ne-chigadzirwa. NewerFGD masisitimushandisa oxidation reactor umo calcium sulfite slurry inoshandurwa kuita calcium sulfate (gypsum); aya anonzi se limestone akamanikidzwa oxidation (LSFO) FGD masisitimu.
Yakajairika yemazuva ano LSFO FGD masisitimu anoshandisa angave shongwe yekupfapfaidza inonyudza ine yakakosha oxidation reactor mubhesi (Mufananidzo 1) kana jet bubbler system. Mune yega yega gasi inobatwa mune limestone slurry pasi peanoxic mamiriro; slurry inobva yaenda kune aerobic reactor kana reaction zone, uko sulfite inoshandurwa kuita sulfate, uye gypsum precipitates. Hydraulic detention time mune oxidation reactor ingangoita maminetsi makumi maviri.
1. Pfapfaidza mbiru limestone kumanikidzwa oxidation (LSFO) FGD hurongwa. Mune LSFO scrubber slurry inoenda kune reactor, uko mweya unowedzerwa kumanikidza oxidation ye sulfite kuita sulfate. Iyi oxidation inoratidzika kushandura selenite kuita selenate, zvichikonzera matambudziko ekurapa gare gare. Kunobva: CH2M HILL
Aya masisitimu anowanzo shanda neakamiswa marara e14% kusvika 18%. Masimbi akaturikwa anosanganisira akaomesesa uye akaomarara egypsum, madota enhunzi, uye zvinhu zvine inert zvakaunzwa neraimu. Kana iyo yakaoma inosvika pamuganhu wepamusoro, slurry inocheneswa. Mazhinji LSFO FGD masisitimu anoshandisa mechanical solids kupatsanurwa uye dewatering masisitimu kuti aparadzanise gypsum uye zvimwe zvakaonda kubva pakuchenesa mvura (Mufananidzo 2).
2. FGD bvisa gypsum dewatering system. Mune yakajairwa gypsum dewatering system zvimedu muchenese zvinoiswa mumapoka, kana kupatsanurwa, kuita zvikamu zvakakasharara uye zvakanaka. Fine particles akapatsanurwa mukufashukira kubva kuhydroclone kuti ibudise underflow iyo inosanganisira yakawanda yakakura gypsum crystals (yekutengesa inogona kutengeswa) inogona kuderedzwa kusvika kune yakaderera mwando ine vacuum bhandi dewatering system. Kunobva: CH2M HILL
Mamwe masisitimu eFGD anoshandisa giravhiti gobvu kana kugadzika madziva ekuisa muganho wezvakaoma uye kubvisa mvura, uye mamwe anoshandisa macentrifuges kana rotary vacuum dhiramu dewatering masisitimu, asi mazhinji masisitimu matsva anoshandisa hydroclones uye vacuum mabhandi. Vamwe vanogona kushandisa ma hydroclones maviri munhevedzano kuti vawedzere kubviswa kwakasimba muhurongwa hwekubvisa mvura. Chikamu chekufashukira kwehydroclone chinogona kudzoserwa kuFGD system kuderedza kuyerera kwemvura yakasviba.
Kuchenesa kunogonawo kutangwa kana paine kuunganidzwa kwekloridi muFGD slurry, zvichidikanwa nemiganhu inoiswa nekupokana kwekuora kweFGD system yekuvaka.
FGD Wastewater Characteristics
Mazhinji akasiyana anokanganisa kuumbwa kwemvura yetsvina yeFGD, senge marasha uye limestone kuumbwa, rudzi rwekukwesha, uye gypsum-dewatering system inoshandiswa. Marasha anobatsira magasi ane acidic - senge chlorides, fluorides, uye sulfate - pamwe nesimbi dzinoputika, kusanganisira arsenic, mercury, selenium, boron, cadmium, uye zinc. Iyo limestone inopa simbi uye aluminium (kubva kune yevhu zvicherwa) kune iyo FGD tsvina yemvura. Limestone inowanzo pwanywa mubhora rakanyorova, uye kukukurwa nekuora kwemabhora kunopa simbi kune limestone slurry. Clays anowanzo kupa iyo inert faindi, chinova chimwe chezvikonzero zvinoita kuti tsvina icheneswe kubva mukukwesha.
Kubva: Thomas E. Higgins, PhD, PE; A. Thomas Sandy, PE; naSirasi W. Givens, PE.
Email:[email yakachengetedzwa]
Nguva yekutumira: Aug-04-2018