Disc Diffuser Selection Guide: Xaiv cov khoom tsim nyog rau txhua qhov project

Hauv kev kho cov dej khib nyiab hauv nroog thiab cov chaw kho mob effluent, aeration systems feem ntau suav rau50% mus rau 70% ntawm tag nrho cov nroj tsuag siv zog. Raws li lub hauv paus ntsiab lus ntawm lub aeration system, lub disc diffuser ncaj qha txiav txim siab oxygen hloov efficiency, blower hwj chim kos, thiab ntev - cov nqi tu lub sij hawm. Txawm li cas los xij, hauv kev xyaum, ntau qhov haujlwm ua haujlwm rau cov kev qhia tshwj xeeb yam tsis tau ua cov txheej txheem xaiv cov txheej txheem - ua rau cov tshuab loj loj, cov qauv tsis sib xws, thiab hloov cov membrane ntxov ntxov. Kab lus no muab cov txheej txheem txheej txheem rau kev xaiv disc diffuser, suav nrog rau 6 qhov kev tsim qauv tseem ceeb uas txhua tus kws ua haujlwm yuav tsum ntsuas, rov ua dua tsib-txoj kev xaiv cov txheej txheem, thiab cov ntaub ntawv ntxaws ntxaws los ntawm 100,000 m³/ hnub municipal cog upgrade.

1. TXOJ CAI KOM TSEEB PARAMETERS ua ntej xaiv

1.1 Cua Flow Rate

Huab cua txaus tus nqi yog qhov kev xaiv tseem ceeb rau txhua qhov disc diffuser. Tus qauv zoo- npuas disc diffusers feem ntau ua haujlwm nyob rau hauv ntau qhov tsim ntawm1 a8nm³/h per unit, nrog rau qhov chaw qab zib rau cov ntawv thov hauv nroog feem ntau poob ntawm 2 thiab 4 Nm³/h. Ua haujlwm qis dua 1 Nm³/ h ua rau muaj kev kub ntxhov tsis txaus los khaws cov khib nyiab hauv kev ncua thiab yuav ua tsis tau raws li kev xav tau ntawm cov pa roj ntsha. Conversely, tshaj 8 Nm³/h ua rau ntxhib, nrawm- nce npuas uas txo cov pa oxygen hloov mus los ntawm 15% mus rau 25% thiab tuaj yeem ua rau cov neeg kho tshuab kev nyuaj siab uas ua rau cov membrane tearing ntawm cov ntsiab lus perforation. Ib txoj cai ntawm tus ntiv tes xoo yog uaxaiv tus nqi ntws hauv qis dua - mus rau - nruab nrab ntawm lub qhov rais ua haujlwm, tshwj tseg rau sab sauv rau qhov siab tshaj -load peev txheej ntau dua li kev ua haujlwm tas mus li.

1.2 Bubble Size thiab Standard Oxygen Transfer Efficiency (SOTE)

Fine npuas disc diffusers tsim npuas nrog txoj kab uas hla1 rau 3mm, ua kom tiav Standard Oxygen Transfer Efficiency (SOTE) ntawm25% mus rau 35% ib 'meter' ntawm submergencehauv dej huv. Qhov no yog kwv yees li 40% mus rau 60% siab dua coarse- npuas lwm, uas txhais ncaj qha rau hauv qis blower horsepower thiab txo nqi zog. Rau siab - muaj zog cov dej khib nyiab nrog siab COD concentrations lossis qis - qhov kub thiab txias (hauv qab 10 ° C),EPDM membrane disc diffusers nrog finer pore qhov ntau thiab tsawg thiab loj dua qhov chaw ntonyiam, raws li lawv them rau qhov txo qis oxygen mass hloov coefficient ntawm qhov kub thiab txias. Kev nkag siab tias SOTE tsis yog tus lej ruaj khov - nws txawv nrog tus nqi airflow, submergence depth, thiab membrane condition - yog qhov tseem ceeb rau qhov tseeb qhov system sizing.

1.3 Kev Pabcuam Thaj Tsam thiab Txheej Txheej Ceev

Txhua disc diffuser feem ntau npog thaj tsam kev pabcuam ntawm0.5m 3 m², nyob ntawm lub pas dej geometry, dej qhov tob, thiab lub hom phiaj oxygen faib profile. Qhov chaw npog tsis yog tsuas yog tag nrho cov phiab hauv pem teb thaj tsam faib los ntawm diffuser suav - nws yuav tsum suav rau cov pa oxygen dispersion cones sib tshooj uas tsim nyob ib ncig ntawm txhua qhov diffuser. Rau cov ntsaws- ntws basins, ib qho tseem ceeb tsim kev txiav txim siab yog qhov ntawddiffuser ceev yuav tsum tau txo nyob rau hauv txoj kev khiav: denser spacing ntawm lub inlet qhov twg organic load yog siab tshaj, sparser mus rau lub qhov hluav taws xob qhov twg BOD tau raug txo kom ntau. Qhov kev ua tiav tiav no tiv thaiv dhau - aeration ntawm tus Tsov tus tw kawg thaum ua kom muaj cov pa oxygen txaus ntawm lub taub hau ntawm lub phiab, txhim kho tag nrho lub zog ntawm 10% mus rau 15% piv rau cov qauv sib xws - daim phiaj layouts.

1.4 Dej Qhov tob thiab Backpressure

Txhua 'meter' ntawm dej tob ntxiv kwv yees li9.8 kPa ntawm hydrostatic backpressurentawm lub diffuser membrane thiab lub tshuab blower. Thaum lub pas dej tob txhim kho cov pa oxygen los ntawm kev ua npuas ntau ntxiv - lub sijhawm sib cuag dej, lawv kuj xav tau siab dua los ntawm cov tshuab tshuab. Rau installation nyob rau hauv basinssiab tshaj 6 meters hauv qhov tob, cov ntaub ntawv txhawb zog thiab cov EPDM tuab (feem ntau 2.0 mus rau 2.5 hli) tau pom zoo kom tiv thaiv kom tsis txhob deformation, nkag mus, los yog rupture nyob rau hauv lub siab. Kev sib raug zoo ntawm qhov tob, SOTE, thiab tus nqi hluav taws xob yog nonlinear - qhov nce SOTE nce ntxiv ntawm qhov tob ntawm qhov tob diminishes tshaj li ntawm 7 meters, thaum lub tshuab hluav taws xob noj txuas ntxiv mus ntxiv. Tus nqi- kev tshuaj xyuas qhov txiaj ntsig xav txog ob qho peev thiab 10-xyoo tus nqi khiav lag luam yuav tsum qhia kev xaiv qhov tob.

1.5 Kev khiav hauj lwm kub thiab Media yam ntxwv

Kev xaiv cov khoom siv membrane yog txiav txim los ntawm cov tshuaj lom neeg thiab thermal ib puag ncig ntawm lub aeration phiab.EPDM (ethylene propylene diene monomer)yog tus qauv kev lag luam rau cov dej khib nyiab hauv nroog, muab kev ua haujlwm dav dav ntawm qhov kub thiab txias-40 ° C rau 130 ° C, zoo heev tiv thaiv kev laus thiab UV raug, thiab kev sib tw nqi. Txawm li cas los xij, rau cov dej khib nyiab hauv kev lag luam uas muaj roj, cov kuab tshuaj, lossis cov tshuaj phem, EPDM tuaj yeem o thiab degrade hauv lub hlis. Hauv cov ntawv thov no,silicone daim nyias nyias los yog cov roj tsim tshwj xeeb-cov tshuaj tiv thaiv EPDMyuav tsum tau teev tseg. PTFE-coated membranes muaj tshuaj tiv thaiv ntxiv rau qhov chaw huab cua, txawm tias tus nqi siab dua. Cov lus hauv qab no qhia txog cov txheej txheem xaiv cov khoom tseem ceeb.

1.6 Kev teeb tsa thiab kev saib xyuas

Qhov kev xaiv ntawmtsau -hauv qab thiab liftable (retrievable) installationyog qhov kev txiav txim siab zoo uas cuam tshuam rau ob qho kev siv peev nyiaj thiab kev ua haujlwm ntev - ua haujlwm yooj yim. Tsau - hauv qab kev teeb tsa uas siv cov xov sib txuas lossis lub eeb clamps ntawm cov kav dej hauv qab lub taub hau muab cov nqi qis dua thiab kev tsim kho yooj yim dua. Txawm li cas los xij, ib qho kev tshuaj xyuas los yog hloov pauv yuav tsum tau ua kom tiav cov phiab dewatering - tus nqi thiab sij hawm- siv cov txheej txheem uas tuaj yeem siv tsheb ciav hlau kho mob offline rau3a7 noj. Liftable systems, uas mount diffusers ntawm cov thav duab tshem tau los yog cov caj npab articulated, pab kom tus neeg diffuser tu tsis muaj dewatering. Thaum pib nqis peev yog feem ntau15% mus rau 25% siab dua, qhov kev teeb tsa no txo ​​qis - cov nqi tu lub sij hawm ntev, tshwj xeeb tshaj yog nyob rau hauv cov nroj tsuag uas txwv tsis pub rov ua dua lossis cov ntawv tso cai tawm mus tas li. Rau cov nroj tsuag uas muaj ntau tshaj 500 diffuser units, ib tug liftable configuration feem ntau ua tiav ib tug them rov qab lub sij hawm nyob rau hauv 3 xyoo los ntawm kev txo txij nkawm downtime ib leeg.

2. LUB TSEV -TSUM TSEEM CEEB METHOD

Cov txheej txheem xaiv kev qhuab ntuas kom ntseeg tau tias lub tshuab diffuser tsis muaj qhov tsis zoo (ua rau cov dej tsis zoo - ua raws) lossis loj dhau (khoom peev thiab lub zog). Tsib - cov txheej txheem hauv qab no yog muab los ntawm cov txheej txheem tsim cov sludge tsim tawm thiab tau raug lees paub thoob plaws ntau tshaj 50 lub nroog thiab kev lag luam.

Kauj Ruam 1: Xam cov Standard Oxygen Transfer Rate (SOTR)

Pib nrog tus cwj pwm zoo:COD, BOD₅, thiab ammonia nitrogen concentration, ua ke nrog cov qauv effluent xav tau. SOTR (kg O₂/h) nyob rau hauv cov qauv txheej txheem yog xam los ntawm Qhov Kev Xav Tau Oxygen tiag tiag (AOR) muab faib los ntawm kev kho qhov tseem ceeb. AOR yuav tsum suav rau ob qho tib si carbonaceous BOD tshem tawm thiab nitrification oxygen xav tau - kwv yees li4,6kg 0₂rau kg NH₃-N oxidized. Thaum lub sijhawm thauj khoom siab tshaj plaws (feem ntau yog ntub dej- huab cua ntws), cov pa oxygen xav tau tuaj yeem nce los ntawm 30% mus rau 50%, thiab lub tshuab diffuser yuav tsum tau tsim los tswj cov ncov no yam tsis pub dhau qhov kev txwv siab ntawm ib lub diffuser.

Kauj ruam 2: Txiav txim siab Standard Oxygen Transfer Efficiency (SOTE)

Pib nrog lub chaw tsim khoom diffuser cov dej huv SOTE nkhaus thiab siv cov txheej txheem kho kom haum rau -cov xwm txheej hauv ntiaj teb. Peb qhov kev kho tseem ceeb yuav tsum raug siv:kho qhov kub thiab txias(cov dej sov tuav tsawg dua cov pa oxygen, txo cov tsav tsheb rau kev hloov mus),salinity kho(solved salts hloov ua npuas coalescence tus cwj pwm), thiab covalpha yam(qhov piv ntawm cov txheej txheem- dej los ntxuav- dej oxygen hloov coefficients, feem ntau yog 0.4 txog 0.8 nyob ntawm MLSS concentration thiab surfactant qib). Ib qho zoo- yam ntxwv alpha yam tseem ceeb yog qhov tseem ceeb - overestimating nws los ntawm 0.1 tuaj yeem ua rau 15% mus rau 20% undersizing ntawm lub tshuab aeration.

Kauj Ruam 3: Xam tag nrho Air Demand

Nrog SOTR thiab kho SOTE tsim, tag nrho cov huab cua thov tau muab los ntawm kev sib raug zoo:Total Air Demand (Nm³/h)=SOTR / (0.28 x SOTE), qhov twg 0.28 sawv cev rau feem ntau ntawm cov pa oxygen nyob rau hauv huab cua (0.21 volumetric feem muab faib los ntawm qhov sib piv ceev ntawm tus qauv). Qhov kev suav no ua rau qhov xav tau ntawm blower sizing. Nws yog kev txawj ntse ntxiv ib10% mus rau 15% kev ruaj ntseg yamntawm tag nrho cov huab cua thov kom suav rau daim nyias nyias fouling uas tshwm sim maj mam ntawm kev tu lub voj voog, uas feem ntau txo SOTE los ntawm 5% mus rau 15% dhau 12- txog 18-hli lub sijhawm ua haujlwm.

Kauj ruam 4: Txiav txim seb tus naj npawb ntawm Diffusers thiab layout

Faib tag nrho cov huab cua xav tau (nrog rau kev nyab xeeb yam) los ntawmtsim tus nqi khiav ib diffuserkom tau txais cov naj npawb ntawm cov units. Tus qauv layout - daim phiaj, staggered, los yog sawb - ces txiav txim siab los ntawm lub qhov ntev ntawm lub phiab, inlet / qhov hluav taws xob txoj hauj lwm, thiab hydraulic qauv tshwm sim. Rau cov pas dej da dej ntau dua 10 meters hauv qhov dav, adual - yob qauvnrog cov diffusers tso rau ntawm ob lub taub hau ntev tsim cov qauv helical txaus uas txhim kho kev sib xyaw thiab cov khib nyiab tshem tawm. Qhov sib txawv ntawm diffuser nyob rau hauv cov kev taw qhia perpendicular rau ntws yuav tsum yog0.5 txog 1.5 m, nrog rau qhov sib nrug ze ze ntawm cov phab ntsa hauv phiab kom tiv thaiv qhov chaw tuag. CFD simulation, thaum tsis tas yuav tsum tau ua rau cov haujlwm me me, tau pom zoo rau cov bass nrog cov duab geometry txawv txawv lossis sib xyaw ua ke - cawv recirculation loops.

Kauj Ruam 5: Txheeb xyuas thiab Ua kom zoo

Cov kauj ruam kawg yog qhov system -qib pov thawj. Paub meej tias covhuab cua-rau- dej piv ntawm 4: 1 txog 8: 1- qhov piv txwv qis dua 4: 1 tuaj yeem qhia tias tsis muaj kev sib xyaw, thaum qhov sib piv saum toj no 8: 1 qhia tias muaj peev xwm tshaj - aeration thiab nkim zog. Xyuas kom tseeb tias tus diffuser flux tus nqi (airflow ib chav tsev hauv pem teb cheeb tsam) yog nyob rau hauv qhov kev pom zoo ntawm3-12 Nm³/h per m²ntawm lub pas dej. Kho tus nqi ntws ntawm ib lub diffuser, ntxiv cov chav nyob tos, lossis hloov kho cov kab sib chaws raws li xav tau. Nyob rau theem no, nws kuj yog ib qho kev xyaum zoo rau kev khiav ib yam dab tsi - yog qhov scenario: yog tias ib lub tshuab ua haujlwm offline rau kev saib xyuas, qhov seem diffusers puas tuaj yeem tuav tsawg kawg 60% ntawm kev tsim cov pa oxygen? Yog tias tsis yog, xav txog kev txhim kho lub tshuab hluav taws xob standby lossis ntxiv 5% mus rau 10% ntau lub peev xwm diffuser.

3. KEV THOV VAJTSWV TEJ LUS NYIAJ LUS: MUNICIPAL WWTP UPGRADE

Qhov project Background

A 100,000 m³/ hnub municipal wastewater kho cognyob rau sab hnub tuaj Tuam Tshoj tau ua haujlwm nrog tubular diffusers rau 8 xyoo. Kev soj ntsuam kev ua tau zoo tau nthuav tawm qhov kev poob qis hauv kev hloov pauv oxygen mus rau qhov ua tau zoo - SOTE tau nqis los ntawm qhov qub 28% mus rau kwv yees li 18%, yuam kom tshuab tshuab ua haujlwm ntawm RPM siab dua thiab tsav tsheb kev siv hluav taws xob txhua xyoo zoo tshaj qhov qauv qauv. Txoj cai hloov kho yog ob npaug: txhim kho cov dej ntws zoo los ntawmQib 1A rau quasi-Class IV cov qauv dej saum npoo av(TN tsawg dua 10 mg / L, NH₃-N tsawg dua 1.5 mg/L), thaum tib lub sijhawmtxo aeration zog nojtsawg kawg yog 25%.

Tsim Kev daws teeb meem

Pab pawg engineering xaiv4,800 units ntawm 325 mm inch EPDM membrane disc diffusers, configured ntawm tus tsim ntws tus nqi ntawm 3 Nm³/h per unit. Qhov layout ceev tau teem rau ntawm 2.8 units ib m²ntawm thaj chaw hauv qab phiab, teem rau hauv cov qauv kawm tiav raws li plaub qhov txuas txuas mus txuas - ntws raws. Cov diffusers tau nruab rau ntawm aliftable ncej systemntawm qhov tob ntawm dej ntawm 6.5 meters, ua rau ib tus neeg hloov daim nyias nyias yam tsis muaj dej dewatering. Reinforced EPDM daim nyias nyias nrog lub thickness ntawm 2.2 hli tau teev tseg los tuav lub zog backpressure ntawm kwv yees li 64 kPa ntawm 6.5-meter kev khiav hauj lwm qhov tob.

Cov txiaj ntsig ua haujlwm

Tom qab 12 lub hlis ntawm kev ua haujlwm ruaj khov, cov nroj tsuag tau tshaj tawm cov kev txhim kho tseem ceeb thoob plaws txhua qhov kev ua haujlwm tseem ceeb:SOTE mus txog 32%, ib qho kev txhim kho 78% dhau ntawm qhov degraded tubular system thiab 4 feem pua ​​​​ntawm cov ntsiab lus siab tshaj qhov qub tsim kev cia siab. Cov huab cua - rau - dej piv yogtxo los ntawm 6.5: 1 rau 4.2: 1, coj nws mus rau qhov kev ua tau zoo tshaj plaws thiab tshem tawm qhov tshaj - aeration uas tau ua tus yam ntxwv ntawm kev teeb tsa yav dhau los. Qhov tseem ceeb tshaj plaws,Lub tshuab hluav taws xob siv hluav taws xob txo qis los ntawm 38%, tsim hluav taws xob txhua xyoo txuag ntawm1.8mn kWh- sib npaug li kwv yees li 1,200 tonnes ntawm CO₂emissions zam txhua xyoo. Qhov kwv yees rov qab rau lub sijhawm peev yog18 hli, tom qab uas cov nyiaj khaws cia tau ncaj qha mus rau cov nroj tsuag kev khiav hauj lwm pob nyiaj siv.

Ntsiab Cai

Cov ntaub ntawv no qhia tau tiasKev xaiv diffuser tsis yog kev txiav txim siab ntawm cov khoom- nws yog ib qho teeb meem kev txhim kho engineering nrog cov txiaj ntsig tseem ceeb ntawm nyiaj txiag thiab ib puag ncig. Cov qauv kev kawm tiav ib leeg tau pab kwv yees li 8% ntawm tag nrho cov kev txuag hluav taws xob los ntawm kev tshem tawm tshaj - aeration hauv qis - chaw thau khoom. Lub liftable installation tau ntxiv kwv yees li 18% rau cov khoom siv ua ntej tab sis tau kwv yees kom txuag tau tshaj $ 120,000 hauv kev saib xyuas- cuam tshuam cov nqi poob qis dua 10- xyoo tsim lub neej. 18-hli ROI zoo ib yam nrog kev ua haujlwm zoo diffuser hloov khoom dua tshiab thoob ntiaj teb, qhov twg lub sijhawm them rov qab feem ntau yog los ntawm12 mus rau 30 lub hlisnyob ntawm cov nqi hluav taws xob hauv zos thiab cov nplai cog.

TEEB MEEM

Kev xaiv zoo disc diffuser yog ibsystematic, multi-variable engineering txheej txheemuas yuav tsum suav rau cov yam ntxwv ntawm cov dej tsis zoo, lub pas dej geometry, hom kev ua haujlwm, thiab 10-rau-20- xyoo tus nqi mus ncig - tsis yog tus nqi khoom siv ua ntej xwb. Tej yaam num uas shortcut txheej txheem xaiv los ntawm kev qhia generic diffuser kom muaj nuj nqis thiab layouts niaj hnub raug kev txom nyem los ntawm uneven aeration, ceev daim nyias nyias hnav, thiab lub zog overconsumption uas deb tshaj ib qho kev pib txuag nqi. Peb pom zoo kom koom nrog cov neeg muab khoom siv thaum lub sijhawm ua tau los yog theem pib tsim, zoo ua ntej kev yuav khoom tiav tiav, los txhawb cov chaw tsim khoom tshwj xeeb cov ntaub ntawv kev ua tau zoo thiab kev ua haujlwm. Rau lub hom phiaj tseem ceeb lossis cov phiaj xwm loj,dej huv cov pa oxygen hloov mus kuajthiabCFD simulationsmuab kev txheeb xyuas qhov tseeb tias qhov kev xaiv diffuser configuration yuav ua tau raws li kev kho mob thiab lub zog lub hom phiaj raws li kev ua haujlwm tiag tiag. Rau cov lus nug tshwj xeeb thiab cov lus pom zoo xaiv, thov hu rau peb pab neeg ua haujlwm engineering.