Sedimentation kev sib cais, raws li kev ua haujlwm hauv chav tsev, tau ntev tau siv los tswj kev kho dej thiab yog cov cuab yeej siv dej siv tau zoo. Txhawm rau txhim kho kev sib cais ntawm cov sedimentation, cov phaj inclined lossis inclined tubes feem ntau tau teeb tsa hauv thaj chaw teeb tsa thaum siv, yog li cov txheej txheem ntiav cov txheej txheem tuaj yeem siv tau, ua kom zoo dua ntawm thaj chaw loj thiab kev sib cais siab. Txawm li cas los xij, cov teeb meem uas tshwm sim thaum lub sij hawm thov tsis tshua muaj neeg nyiam. Daim ntawv no tsom mus rau kev tsom xam ntawm cov teeb meem tseem ceeb uas tshwm sim thaum lub sij hawm thov thiab tawm tswv yim sib xws rau kev siv.
1. Cov teeb meem tshwm sim thaum lub sij hawm thov ntawm INCLINED TUBE SETTLER
Yog hais tias cov dej faib ntawm lub inlet ntawm inclined tube settler yog tsis sib xws, loj turbulence yuav tshwm sim nyob rau hauv cov kua txav ze ntawm lub inlet. Qhov no ua rau muaj qhov siab tshaj plaws hauv zos khiav nrawm ntawm qhov nkag, ua rau cov sludge yav tas los tso rau ntawm cov hlab ntsha inclined sawv dua.
Qhov xwm txheej sab hauv ntawm lub raj inclined nyob rau lub sijhawm ua haujlwm ib txwm muaj nyob hauv daim duab 1.
Los ntawm daim duab 1, nws tuaj yeem pom tias cov dej ntws thiab cov sludge ntws txhua tus muaj lawv txoj hauv kev. Yog tias ib txwm ua haujlwm txuas ntxiv mus ntev, qhov kev txav ntawm cov sludge ntws yog nyob ze rau qhov sib npaug sib npaug:
lub sij hawm no SS tshem tawm efficiency ntawm cov dej khib nyiab yog zoo.
Txawm li cas los xij, yog tias qhov kev faib tawm ntawm qhov nkag tsis zoo txaus, qhov ntws nrawm ntawm qee lub raj inlets ua siab dhau, ua rau muaj kev kub ntxhov hnyav thiab ua rau cov dej tsis zoo.
2. FLUID MECHANICS analyses ntawm qhov teeb meem
Thaum tag nrho cov txheej txheem tsis zoo, cov kua dej yuav nthuav tawm qhov xwm txheej pom hauv daim duab 2.
Cov laj thawj rau qhov tshwm sim saum toj no yog txheeb xyuas los ntawm cov hauv qab no.
2.1 Hydraulic tsom xam ntawm qhov xwm txheej tsis zoo
Qhov tseeb, qhov nce thiab nqis ntws ntawm cov dej thiab cov sludge nyob rau hauv cov hlab ntsha inclined tuaj yeem suav tias yog qhov tshwm sim ntawm qhov tshwm sim ntawm fluidisation. Nco ntsoov tias v yog qhov nrawm nrawm ntawm cov dej los ntawm cov raj, u₁ yog qhov tseeb tshaj tawm ntawm cov dej los ntawm cov sludge hais, thiab ε yog qhov tsis muaj feem (ntawm cov sludge particle txheej). Ces u₁=v/ε, raws li qhia hauv daim duab 3.
Yog hais tias qhov tsis muaj feem ntawm cov khib nyiab tshem tawm me me, qhov tseeb tshaj tawm ntawm cov dej los ntawm cov particle txheej yog qhov siab. Yog hais tias lub particle settling tshaj tawm yog hu ua tus nqi ruaj uteeb, raws li txoj kev xav ntawm ntau theem ntawm fluidisation, thaum qhov tseeb tshaj tawm ntawm dej los ntawm particle txheej u₁=uteeb, lub xeev fluidised yog nyob rau hauv ib tug ruaj txaj theem nrog ib tug ruaj khov void feem ε. Thaum u> uteeb, tus thawj void feem ε yog tawg, ua rau ib tug nce nyob rau hauv void feem. Rau ib qho inclined tube settler, qhov no txhais tau hais tias cov khoom nce, txo cov kev sib cais.
2.2 Kev soj ntsuam ntawm qhov sib txawv ntawm qhov sib txawv ntawm cov sludge resuspended hauv ntau lub xeev
Cov resuspended sludge particles muaj nyob rau hauv daim ntawv ntawm ① ib tug neeg hais thiab ② particle pawg ntawm ntau qhov sib txawv (nrog void feem ε'). Raws li kev daws teeb meem tshaj tawm cov qauv rau ib tus neeg hauv cheeb tsam Stokes txoj cai:
Raws li kev sib raug zoo ntawm Steinour, raws li kev txheeb xyuas qhov nrawm ntawm cov pawg particle:
qhov twg:
vt, pab- daws qhov nrawm ntawm pawg particle, m/s;
t - sij hawm, s;
g - gravitational acceleration, m/s²;
ρs, ρL- ceev ntawm particle thiab kua, kg/m³;
Dp- particle txoj kab uas hla, m;
μ - dynamic viscosity coefficient, kg/(m·s);
ε - void feem.
Txij li 0 < ε² < 1 thiab 0 < 10-1.82(1-ε)<1, nws ua raws li ε²·10-1.82(1-ε)<1, li vt, pab
Raws li sedimentation txoj kev xav thiab cov pov thawj saum toj no, tom qab tau resuspended, particle pawg tsis tshua muaj kev sib haum xeeb, piv txwv li, lawv tau yooj yim dua los ntawm cov dej ntws, txo cov sedimentation efficiency.
2.3 Cov yam ntxwv ntws hauv lub xeev tsis zoo
Thaum qhov xwm txheej tsis zoo nyob hauv daim duab 2 tshwm sim, saib hauv qab ntawm cov dej ntawm cov chaw nyob, qhov kev faib tawm ntws zoo li hauv daim duab 4.
Raws li pom nyob rau hauv daim duab 4, peb cheeb tsam tshwm sim nyob rau saum npoo dej: ① ib cheeb tsam nyob ntsiag to, ② ib cheeb tsam hloov, thiab ③ ib cheeb tsam loj heev turbulence. Hauv thaj chaw muaj kev kub ntxhov hnyav, hauv qhov xwm txheej hnyav, cov dej saum npoo kuj tseem tuaj yeem ua rau hauv me me nkhaus arcs. Lub SS concentration ntawm no yog siab heev, yuav luag tib yam li cov influent.
2.4 Ntawm - qhov kev xeem tau ntawm qhov chaw tom qab kho raws li kev txheeb xyuas saum toj no
Nyob rau hauv ib txoj haujlwm kho dej khib nyiab, vim qhov teeb meem saum toj no, cov dej ntws tau zoo dua. Tom qab kev tshuaj xyuas hydraulic thiab kev kho vaj tsev kho kom zoo kom cov dej xa tawm tsis sib xws, qhov tshwm sim ntawm flocs nce tsis tshwm sim hauv cov dej ntws. Cov txiaj ntsig kev xeem tau qhia hauv Table 1.
Table 1 CODcr kuaj cov dej khib nyiab los ntawm qee cov nroj tsuag
| Water sample batch | Influent CODcr/(mg·L⁻¹) | Effluent CODcr/(mg·L⁻¹) | Tshem tawm tus nqi /% |
| 1 | 1272 | 261 | 79.5 |
| 2 | 1153 | 245 | 78.7 |
Los ntawm Table 1, nws tuaj yeem pom tias tom qab kev kho thiab kev faib dej tsis sib xws, CODcr tshem tawm tus nqi mus txog qib siab.
3. Ntau lub ntsiab lus kom ceeb toom rau INCLINED TUBE SETTLER
3.1 Kev soj ntsuam ntawm cov khoom sib txawv
Rau cov khoom sib txawv, xws li xuab zeb sedimentation, floc sedimentation ntawm luam ntawv thiab dyeing khib nyiab, thiab coal slurry sedimentation, vim qhov sib txawv ntawm particle ntom, zoo li, thiab void feem, muaj qhov sib txawv ntawm sedimentation. Sand particles have a relatively high density and small size, so they settle quickly. Flocs from printing and dyeing wastewater have a relatively low density, close to water, large shape, and high void fraction, so they settle slowly. Coal slurry ntog ntawm ob. Yog li ntawd, rau cov xuab zeb sedimentation, cov kev cuam tshuam ntawm cov kev hloov pauv yog me me, thaum luam ntawv thiab dyeing cov dej khib nyiab, cov kev cuam tshuam ntawm kev hloov pauv yog qhov loj. Yog li, cov khoom sib txawv muaj cov kev xav tau sib txawv rau kev faib tawm. Rau kev luam ntawv thiab dyeing cov dej khib nyiab, qhov ntws tawm ntawm qhov nkag yuav tsum zoo ib yam.
3.2 Inclined tube settlers xav tau ntau dua cov dej sib xws
Vim tias cov raj inclined (feem ntau yog 35 hli, 50 hli inch) muab tso rau hauv qhov chaw, thaum lub hydraulic faib nyob rau hauv cov hlab tsis sib xws, vim yog ν=Q / A, qhov ntws nrawm dhau los ua siab dhau hauv qee lub raj, ua rau flocs nce, uas ua rau cov dej ntws zoo txawm tias tsis muaj raj. Yog li ntawd, cov dej faib nyob rau hauv inclined tube settlers yuav tsum zoo ib yam li nyob rau hauv cov dej tso tsheb hlau luam zoo tib yam.
3.3 Cov kev taw qhia kev teeb tsa ntawm cov raj inclined yuav tsum rov qab mus rau qhov kev taw qhia nkag
Cov txheej txheem ntawm cov dej nkag mus rau hauv qhov chaw nyob los ntawm cov yeeb nkab inlet suav nrog qhov loj ntawm qhov ntws hla -section. Yog li ntawd, cov dej tau txais kev hloov luv luv. Txhawm rau zam qhov kev hloov pauv no, cov kev taw qhia kev teeb tsa ntawm cov kav dej inclined yuav tsum rov qab mus rau qhov kev taw qhia nkag. Qhov no tuaj yeem txo qhov cuam tshuam ntawm qhov kev hloov pauv sai sai ntawm kev ntws ntawm cov sedimentation efficiency ntawm flocs.