1. Kev kho mob ua ntej ntawm kev pleev xim dej
Lub cev dej ntuj feem ntau muaj av nkos, av nplaum, humus thiab lwm yam teeb meem tshem tawm thiab colloidal impurities thiab cov kab mob, fungi, algae, kab mob thiab lwm yam kab mob, lawv muaj ib qho kev ruaj ntseg hauv dej, yog lub ntsiab ua rau dej turbidity, xim thiab tsw.Cov organic ntau dhau nkag mus rau hauv ion exchanger, paug cov resin, txo cov peev txheej ntawm cov resin, thiab tseem cuam tshuam rau qhov zoo ntawm cov desalting system.Coagulation kev kho mob, kev hais daws kom meej thiab pom kev kho mob yog tshem tawm cov impurities raws li lub hom phiaj tseem ceeb, kom cov ntsiab lus ntawm tshem tawm cov teeb meem hauv dej raug txo kom tsawg dua 5mg / L, uas yog, kom tau txais cov dej ntshiab.Qhov no yog hu ua dej pretreatment.Tom qab pretreatment, cov dej yuav siv tau raws li boiler dej tsuas yog thaum cov ntsev yaj nyob rau hauv cov dej raug tshem tawm los ntawm ion txauv thiab cov yaj gases nyob rau hauv dej raug tshem tawm los ntawm cua sov los yog nqus los yog tshuab.Yog tias cov impurities no tsis raug tshem tawm ua ntej, kev kho tom ntej (desalting) tsis tuaj yeem ua.Yog li ntawd, kev kho cov dej coagulation yog qhov txuas tseem ceeb hauv cov txheej txheem kho dej.
Cov txheej txheem pretreatment ntawm thermal fais fab nroj tsuag yog raws li nram no: raw dej → coagulation → nag lossis daus thiab clarification → pom.Cov coagulants feem ntau siv hauv cov txheej txheem coagulation yog polyaluminum chloride, polyferric sulfate, aluminium sulfate, ferric trichloride, thiab lwm yam. Cov hauv qab no feem ntau qhia txog kev siv polyaluminum chloride.
Polyaluminium chloride, hu ua PAC, yog ua raws li txhuas tshauv lossis txhuas cov khoom siv raw li cov ntaub ntawv raw, ntawm qhov kub thiab txias thiab qee qhov siab nrog alkali thiab txhuas cov tshuaj tiv thaiv ua polymer, raw cov ntaub ntawv thiab cov txheej txheem ntau lawm yog txawv, cov khoom specifications tsis zoo ib yam.Cov mis mos molecular ntawm PAC [Al2(OH)nCI6-n]m, qhov twg n tuaj yeem yog cov lej ntawm 1 thiab 5, thiab m yog tus lej ntawm pawg 10. PAC tuaj yeem ua ob hom khoom thiab kua.
2.Coagulation mechanism
Muaj peb yam tseem ceeb ntawm coagulants ntawm colloidal hais hauv dej: hluav taws xob neutralization, adsorption bridging thiab cheb.Qhov twg ntawm peb qhov teebmeem no yog qhov tseem ceeb nyob ntawm hom thiab ntau npaum li cas ntawm coagulant, qhov xwm txheej thiab cov ntsiab lus ntawm colloidal hais hauv dej, thiab pH tus nqi ntawm cov dej.Cov txheej txheem ntawm kev txiav txim ntawm polyaluminium chloride zoo ib yam li txhuas sulfate, thiab tus cwj pwm ntawm txhuas sulfate hauv dej yog hais txog cov txheej txheem ntawm Al3+ ua ntau hom hydrolyzed.
Polyaluminium chloride tuaj yeem suav tias yog ntau yam khoom nruab nrab hauv cov txheej txheem ntawm hydrolysis thiab polymerization ntawm txhuas chloride rau hauv Al (OH) 3 nyob rau hauv qee yam mob.Nws yog tam sim no ncaj qha nyob rau hauv dej nyob rau hauv daim ntawv ntawm ntau hom polymeric thiab A1 (OH) a(s), tsis muaj cov txheej txheem hydrolysis ntawm Al3+.
3. Daim ntawv thov thiab muaj feem cuam tshuam
1. Dej kub
Cov dej kub muaj qhov cuam tshuam rau kev kho coagulation.Thaum cov dej kub qis, qhov hydrolysis ntawm cov coagulant nyuaj dua, tshwj xeeb tshaj yog thaum cov dej kub qis dua 5 ℃, qhov hydrolysis qeeb qeeb, thiab cov flocculant tsim muaj cov qauv xoob, cov ntsiab lus dej siab thiab cov khoom zoo.Thaum cov dej kub qis, qhov kev daws teeb meem ntawm cov khoom colloidal yog txhim kho, lub sij hawm flocculation yog ntev, thiab cov sedimentation qeeb.Kev tshawb fawb qhia tau hais tias cov dej kub ntawm 25 ~ 30 ℃ yog tsim nyog.
2. pH tus nqi ntawm cov dej
Cov txheej txheem hydrolysis ntawm polyaluminium chloride yog txheej txheem ntawm kev tso tawm tas li ntawm H +.Yog li ntawd, nyob rau hauv txawv pH tej yam kev mob, yuav muaj sib txawv hydrolysis intermediates, thiab qhov zoo tshaj plaws pH tus nqi ntawm polyaluminium chloride coagulation kev kho mob yog feem ntau ntawm 6.5 thiab 7.5.Cov nyhuv coagulation yog siab dua nyob rau lub sijhawm no.
3. Kev siv tshuaj coagulant
Thaum cov coagulant ntxiv tsis txaus, qhov seem turbidity nyob rau hauv cov dej tawm yog loj dua.Thaum tus nqi ntau dhau lawm, vim hais tias cov colloidal hais nyob rau hauv cov dej adsorb ntau coagulant, cov nqi khoom ntawm cov colloidal hais hloov, uas ua rau cov residual turbidity nyob rau hauv lub effluent nce ntxiv.Cov txheej txheem coagulation tsis yog cov tshuaj lom neeg yooj yim, yog li qhov yuav tsum tau noj tsis tuaj yeem txiav txim siab raws li kev suav, tab sis yuav tsum tau txiav txim siab raws li cov dej tshwj xeeb los txiav txim siab npaum li cas;Thaum cov dej zoo hloov raws caij nyoog, cov tshuaj yuav tsum tau hloov raws li qhov xav tau.
4. Hu rau nruab nrab
Hauv cov txheej txheem ntawm kev kho coagulation lossis lwm yam kev kho nag lossis daus, yog tias muaj qee qhov av nkos txheej hauv dej, cov nyhuv ntawm kev kho coagulation tuaj yeem txhim kho tau zoo.Nws tuaj yeem muab thaj chaw loj, los ntawm adsorption, catalysis thiab crystallization core, txhim kho cov nyhuv ntawm kev kho coagulation.
Coagulation nag lossis daus yog ib txoj kev siv dav rau kev kho dej tam sim no.Polyaluminium chloride kev lag luam yog siv los ua cov dej kho flocculant, nrog kev ua haujlwm zoo coagulant, loj floc, tsawg npaum li cas, kev ua haujlwm siab, nag lossis daus, dav siv ntau yam thiab lwm yam zoo, piv nrog cov tshuaj flocculant ib txwm tuaj yeem txo los ntawm 1/3 ~ 1 / 2, tus nqi yuav txuag tau 40%.Ua ke nrog kev ua haujlwm ntawm valveless lim thiab activated carbon lim, turbidity ntawm cov dej nyoos yog txo kom zoo, cov effluent zoo ntawm lub desalt system yog zoo dua, thiab pauv peev xwm ntawm desalt resin kuj nce, thiab cov nqi khiav hauj lwm yog txo.
Post lub sij hawm: Mar-22-2024
