p

n x l cp ncTnh ton h thng x l nc cp cng sut 40.000m3/ng cp cho khu dn c A ti ng Nai

MC LC

CHNG 1: TNG QUAN - GII THIU 1.1 Tng quan v nc ngm 61.2 Thnh phn tnh cht nc ngm 7 1.3 u nhc im khi s dng nc ngm8 CHNG 2: TNG QUAN CC PHNG PHP X L NC NGM2.1 X l nc ngm bng phng php c hc 102.2 X l nc ngm bng phng php ha l 122.3 xut phng n x l 15CHNG 3: THIT K TNH TON CNG TRNH N V3.1 Tnh gin ma 173.2 Tnh b trn 233.4 B lng li tm263.5 B lc nhanh303.6 Cng trnh ti vi403.8 Kh trng nc 413.9 B cha nc sch423.10 Trm bm cp 2423.11 Ging khoan43CHNG 4: CAO TRNH CC CNG TRNH4.1 Cao trnh b cha nc sch434.2 Cao trnh b lc 434.5 Cao trnh b trn 434.6 Cao trnh gin ma 43

TRNG H TI NGUYN V MI TRNGCNG HA X HI CH NGHA VIT NAMTHNH PH H CH MINHC LP T DO HNH PHC

NHIM V N MN HC X L NC CPGio Vin Hng Dn: Ths. Bin Vn Tranh H V Tn Sinh Vin: Hong n Duyn MSSV: 0510020058 Lp: 05KTMT1Ngnh:KThut Mi trngKhoa: Mi Trng B Mn: K Thut X L Nc Cp1. Ngy nhn n: 02 05 - 20132. Ngy hon thnh n: 20-06-2013.3. u n: Tnh ton h thng x l nc cp cng sut 40.000m3/ng cp cho khu dn c A ti ng Nai.4. yu cu v s liu ban u: Ngun nc x l : nc ngm . S liu cht lng nc ngun cho bng sau:STTCh tiun vNng

1pH6.5

2 cN.T.U9

3 mu (Pt Co)mgl/l5

4 kim (CaCo3)mg/l5.5

5Hm lng cn nc ngunmg/l15

6Tng hm lng cc mui ha tanmg/l300

7Hm lng st tngmg/l26

8Oxi ha

mg/l4

9Hm lng CO2 ban u c trong nc ngunmg/l160

10Nhit nc0C20

Tiu chun nc sau x l t quy chun k thut quc gia v cht lng nc n ung Din tch khu t d kin xy dng trm x l nc cp cho khu dn c l 200m x 600m5.Ni dung phn tnh ton v thuyt minh: Lp bn thuyt minh v tnh ton bao gm : Phn tch v xut phng n x l nc cp cho khu dn c trn. Tnh ton 03 cng trnh n v chnh trong phng n xut . Tnh ton v la chn thit b (bm nc, thieests b khuy trn,) cho cc cng trnh n v tnh ton trn.6. Cc bn v k thut V bn v mt ct cng ngh ca phng n chn: 01 bn v kh A1 TP.HCM, ngy 02 thng 05 nm 2013

NHN XT CA GIO VIN HNG DN

NHN XT CA GIO VIN PHN BIN

CHNG I : TNG QUAN-GII THIU

1.1TNG QUAN V NC NGM Vit nam l quc gia c ngun nc ngm kh phong ph v tr lng v kh tt v cht lng. Nc ngm tn ti trong cc l hng v cc khe nt ca t c to thnh trong giai on trm tch t hoc do s thm thu , thm ca ngun nc mt , nc ma nc ngm c th tn ti cch mt t vi mt, vi chc mt hay hng trm mt. i vi cc h thng cp nc cng ng th ngun nc ngm lun lun l ngun nc c a thch. Bi v cc ngun nc mt thng b nhim v lu lng khai thc phi ph thuc vo s bin ng theo ma . Ngun nc ngm t chu tc ng ca con ngi . Cht lng nc ngm thng tt hn cht lng nc mt nhiu. Trong nc ngm hu nh khng c cc ht keo t hay cc ht l lng v vi sinh , vi trng gy bnh thp.. Cc ngun nc ngm hu nh khng cha rong to, mt trong nhng nguyn nhn gy nhim ngun nc. Thnh phn ng quan tm trong nc ngm l cc tp cht ho tan do nh hng ca iu kin a tng, thi tit, nng ma, cc qu trnh phong ho v sinh ho trong khu vc. nhng vng c iu kin phong ho tt, c nhiu ht bn v lung ma ln th cht lng nc ngm d b nhim bi cc cht khong ho tan, cc cht hu c, mn lu ngy theo nc ma ngm vo t. Nc ngm c ngun gc t nc ma, nc mt v hi nc trong khng kh ngng t li v thm thu co lng t. Cht lng nc ngm ph thuc vo thnh phn khong ha v cu trc a tng m nc thm qua. Do vy nc chy qua cc a tng cha ct v granit thng c tnh axit v cha t cht khong. Khi nc ngm chy qua a tng cha vi th nc thng c cng v kim hydrocacbonat kh cao. Ngoi ra nc ngm cn c nhng c tnh chung: c thp. Nhit v thnh phn ha hc tng i n nh. Khng c oxy nhng c th cha nhiu kh nh: CO2, H2S, Cha nhiu khong cht ha tan ch yu l: Fe, Mn, Ca, Mg, Khng c hin din ca vi sinh vt. Hm lng cn nh.1.2 THNH PHN V TNH CHT CA NC NGM c tnh chung v thnh phn, tnh cht ca nc ngm l nc c c thp, nhit v cc thnh phn ha hc t thay i, nc khng c oxy ha trong mi trng khp kn l ch yu, thnh phn ca nc c th thay i t ngt vi s thay i c v nhim khc nhau. Nhng thay i ny lin quan n s thay i lu lng ca lp nc sinh ra do nc ma. Thnh phn, tnh cht nc ngm ph thuc vo ngun gc, cu trc a tng ca khu vc v chiu su ca lp nc ngm Trong nc ngm khng cha rong, to l yu t d gy nhim ngun nc nhng chng li cha cc tp cht ho tan do nh hng ca iu kin a tng, cc qu trnh phong ho v sinh ho trong khu vc. nhng vng c iu kin phong ho tt, ma nhiu hoc b nh hng ca ngun thi th trong nc ngm d b nhim bi cc cht khong ho tan, cc cht hu c. Bn cht a cht ca khu vc nh hng ln n thnh phn ho hc ca nc ngm v nc lun tip xc vi t trong n c th lu thng hoc b gi li. Gia nc v t lun hnh thnh nn s cn bng v thnh phn ho hc, v vy thnh phn ca nc th hin thnh phn ca a tng khu vc . Tuy vy, nc ngm c mt s c tnh chung l: c thp, nhit v thnh phn ho hc t thay i theo thi gian, ngoi ra nc ngm thng cha rt t vi khun, tr trng hp ngun nc b nh hng ca nc b mt. Cc c tnh ca nc ngm: Nhit ca nc ngm tng i n nh. c thng thay i theo ma. mu: Thng th khng c mu, mu gy ra do cha cc cht ca acid humic. khong ho thng khng thay i. St v mangan thng c mt vi cc hm lng khc nhau. CO2 thng xm thc vi hm lng ln. xi ho tan thng khng c. H2S thnh thong c mt trong nc ngm. NH4+ thng c mt trong nc ngm. Nitrat, Silic c hm lng i khi cao. t b nh hng bi cc cht v c v hu c. Clo c th b nh hng hoc khng b nh hng tu theo khu vc. Vi sinh vt: Thng c vi khun st. Trong nc ngm thng khng c mt oxi ho tan nhng c hm lng CO2 cao, thng c hm lng st tng cng vi cc mc khc nhau, t vi mg/l n 100 mg/l hoc ln hn, vt xa tiu chun cho php vi nc n ung sinh hot ( tiu chun cho php i vi hm lng st trong nc n ung sinh hot l 0,3 mg/l, i vi khu vc th l 0,5 mg/l i vi khu vc nng thn). Do cn phi x l trc khi a vo s dng. Mt c im khc cn quan tm l pH trong nc thng kh thp, nhiu ni pH gim n 3 4 ( do hm lng CO2 cao), khng thun li cho vic s l nc.1.3U V NHC IM KHI S DNG NC NGM1.3.1. u im Nc ngm l ti nguyn thng xuyn, t chu nh hng ca cc yu t kh hu nh hn hn. Cht lng nc tng i n nh, t b bin ng theo ma nh nc mt. Ch ng hn trong vn cp nc cho cc vng ho lnh, dn c tha, nht l trong hon cnh hin nay bi v nc ngm c th khai thc vi nhiu cng sut khc nhau. khai thc nc ngm c th s dng cc thit b in nh bm ly tm, my nn kh, bm nhng chm hoc cc thit b khng cn in nh cc loi bm tay. Ngoi ra nc ngm cn c khai thc tp trung ti cc nh my nuc ngm, cc x nghip, hoc khai thc phn tn ti cc h dn c. y l u im ni bt ca nc ngm trong vn cp nc nng thn. Gi thnh x l nc ngm nhn chung r hn so vi nc mt.1.3.2. Nhc im Mt s ngun nc ngm tng su c hnh thnh t hng trm, hng nghn nm v ngy nay nhn c rt t s b cp t nc ma. V tng nc ny ni chung khng th ti to hoc kh nng ti to rt hn ch. Do vy trong tng lai cn phi tm ngun nc khc thay th khi cc tng nc ny b cn kit. Vic khai thc nc ngm vi qui m v nhp iu qu cao cng s lm cho hm lng mui trong nc tng ln t dn n vic tng chi ph cho vic x l nc trc khi a vo s dng. Khai thc nc ngm vi nhp iu cao s lm cho mc nc ngm h thp xung, mt mt lm cho qu trinh nhim mn tng ln, mt khc lm cho nn t b vng xung gy h hi cc cng trnh xy dng-mt trong cc nguyn nhn gy hin tng ln st t. Khai thc nc ngm mt cch ba bi cng d dn ti tnh trng nhim ngun nc ngm.

CHNG 2 TNG QUAN V PHNG PHP X L NC NGM2.1. X L NC NGM BNG PHNG PHP C HC2.1.1 Cng trnh thu nc ngm c th chia thnh cc loi sau: Ging khoan:l cng trnh thu nc nm mch su. su khoan ph thuc vo su tng cha nc, thng nm trong khong 20 200m, i khi c th ln hn. Ging khoan c s dng rng ri trong mi trm x l. Hin nay c 4 loi ging khoan ang c s dng: Ging khoan hon chnh, khng p Ging khoan khng hon chnh, khng p Ging khoan hon chnh, c p Ging khoan khng hon chnh c p Cu to ging khoan gm Ming ging ng vch gia c v bo v ging ng lc ng lng Ging khi: l cng trnh thu nc ngm mch nng, thng khng p i khi p lc yu, ch p dng i vi cc im dng nc nh hoc h gia nh l. ng hm thu nc: c p dng thu nc ngm mch nng, su tng cha nc khng qu 8m, cung cp cho nhng im dng nc vi lu lng nh. Cng trnh thu nc ngm mch l thin Cng trnh thu nc thm2.1.2 B lng: Mc ch ca b lng l nhm lng cn nc, lm sch s b trc i nc vo b lc hon than qu trnh lm trong nc. Trong thc t thng dng cc loi b lng sau ty thuc vo cng sut v cht lng nc m ngi ta s dng B lng ngang: c s dng trong cc trm x l c cng sut >30000m3/ng i vi trng hp x l nc c dng phn v p dng vi bt k cng sut no cho cc trm x l khng dng phn. B lng ng: thng c p dng cho nhng trm x l c cng sut nh hn (n 3000 m3/ng). B lng ng hay b tr kt hp vi b phn ng xoy hnh tr. B lng trong c lp cn l lng: hiu qu x l cao hn cc b lng khc v tn t din tch xy dng hn nhng b lng trong c cu to phc tp, ch qun l vn hnh kh, i hi cng trnh lm vic lin tc v rt nhy cm vi s dao ng lu lng v nhit ca nc. B ch p dng i vi cc trm c cng sut n 3000m3/ng. B lng li tm: c dng hnh trn, ng knh t 5m tr ln. B thng c p dng s lng cc ngun nc c hm lng cn cao(>2000mg/l) vi cng sut >=30000 m3/ng th c hoc khng dng cht keo t2.1.3 B lc B lc chm: dng x l cn bn, vi trng c trong nc b gi li trn lp mng lc. Ngoi ra b lc chm dng x l nc khng dng phn, khng i hi s dng nhiu my mc, thit b phc tp, qun l vn hnh n gin. Nhc im ln nht l tc lc nh, kh c gii ha v t ng ha qu trnh ra lc v vy phi qun l bng th cng nng nhc. B lc chm thng s p dng cho cc nh my c cng sut n 1000m3/ng vi hm lng cn n 50mg/l, mu n 50 B lc nhanh: l b lc nhanh mt chiu, dng nc lc i t trn xung, c mt lp vt liu l ct thch anh. B lc nhanh ph thng c s dng trong dy chuyn x l nc mt c dng cht keo t hay trong dy chuyn x l nc ngm B lc nhanh 2 lp: c nguyn tc lm vic ging b lc nhanh ph thng nhng c 2 lp vt liu lc l ct thch anh v than angtraxit nhm tng tc lc v ko di chu k lm vic ca b. B lc s b: c s dng lm sch nc s b trc khi lm sch trit trong b lc chm. B lc ny lm vic theo nguyn tc b lc nhanh ph thng B lc p lc: l mt loi bo v nhanh kn, thng c ch to bng thp c dng hnh tr ng cho cng sut nh v hnh tr ngang cho cng sut ln. Loi b ny c p dng trong dy chuy x l nc mt c dng cht phn ng khi hm lng cn ca nc ngun ln n 50mg/l, c ln n 80 vi cng sut trm x l n 300m3/ng, hay dng trong cng ngh kh st khi dng ejector thu kh vi cng sut 0,6m Hiu qu: Kh c 30 35% CO2 Tc lc 5 7m/h; d = 0,9 1,3mm; Hvll = 1,0 1,2m Cng r lc bng nc 10 12l/s.m2; bng kh 20l/s.m2 Fe 6,82.2.2 Dn ma: lm thong t nhin. Kh c 75 80% CO2, tng DO (55% DO bo ha) Cu to dn ma gm: H thng phn phi nc Sn tung nc (1 4 sn), mi sn cch nhau 0,8m Sn vt liu tip xc Sn v ng thu nc2.2.3 Thng qut gi: lm thong ti trng cao(lm thong cng bc) ngha l gi v nc i ngc chiu. Kh c 85 90% CO2, tng DO ln 70 85% DO bo ha. Cu to: H thng phn phi nc Lp vt liu tip xc2.2.4 Clo ha s b Clo ha s b l qu trnh cho clo vo nc trc b lng v b lc, mc ch ca clo ha s b l: Ko di thi gian tip xc tit trng khi ngun nc b nhim bn nng. Oxy ha st ha tan dng hp cht hu c, oxy ha mangan ha tan to thnh cc kt ta tng ng. Oxy ha cc cht hu c kh mu. Trung ha amoniac thnh cloramin c tnh cht tit trng ko di. Clo ha s b c tc dng ngn chn s pht trin ca rong, ru trong b phn ng to bng cn v b lng, ph hy t bo ca cc vi sinh sn ra cht nhy nht trn mt b lc, lm tng thi gian cua chu k lc.2.2.5 Keo t - to bng Keo t v bng cn l qu trnh to ra cc tc nhn c kh nng kt dnh cc cht lm bn nc dng l lng thnh cc bng cn c kh nng lng c trong b lng hay kt dnh trn b mt ht ca lp vt liu lc vi tc nhanh v kinh t nht. Khi trn u phn vi nc cn x l, cc phn ng ha hc v ha l xy ra to thnh h keo dng phn tn u trong nc. Khi c trung ha, h keo dng ny l cc ht nhn c kh nng dnh kt vi cc keo m phn tn trong nc v dnh vi nhau to thnh cc bng cn. Do , qu trnh to nhn kt dnh gi l qu trnh keo t cn qu trnh kt dnh cn bn v nhn keo t gi l qu trnh phn ng to bng cn. Trong k thut x l thng dng phn nhm Al2(SO4)3, phn st FeCl3, Fe2(SO4)3 v FeSO4. Nhng hin nay Vit Nam thng s dng phn nhm, cn phn st c hiu qu keo t cao, nhng cc qu trnh khc nh sn xut, vn chuyn, phc tp v trong qu trnh x l d lm nc c mu vng nn t c s dng trong k thut x l nc cp. Hiu qu ca qu trnh to bng ph thc vo cng v thi gian khuy trn cc nhn keo t v cn bn va chm v kt dnh vo nhau. tng cng qu trnh to bng, thng cho vo b phn ng to bng cn cht tr keo t polyme. Khi tan vo nc, polymer s to ra lin kt di loi anion nu trong nc cn x l thiu ion i (nh SO22-,) hay loi trung tnh nu thnh phn ion v kim ca nc ngun tha mn iu kin keo t.2.2.6 Kh trng nc Kh trng nc l khu bt buc trong qu trnh x l nc n ung sinh hot. Trong nc thin nhin cha rt nhiu vi sinh vt v kh trng. Sau cc qu trnh x l c hc, nht l nc sau khi qua b lc, phn ln cc vi trng b gi li. Song tiu dit hon ton cc vi trng gy bnh, cn phi tin hnh kh trng nc. Hin nay c nhiu bin php kh trng c hiu qu nh: kh trng bng cc cht oxy ha mnh, cc tia vt l, siu m, phng php nhit, ion kim loi nng,1. Kh trng bng Clo v cc hp cht ca Clo Clo l mt cht oxy ha mnh bt c dng no. Khi Clo tc dng vi nc to thnh axit hypoclorit (HOCl) c tc dng dit trng mnh. Khi cho Clo vo nc, cht dit trng s khuch tn xuyn qua v t bo vi sinh vt v gy phn ng vi men bn trong ca t bo, lm ph hoi qu trnh trao i cht dn n vi sinh vt b tiu dit. Qu trnh tiu dit vi sinh vt xy ra nh sau: u tin cht dit trng i qua mng t bo ca vi sinh vt, sau phn ng vi men bn trong mng t bo cn tr qu trnh trao i cht bn trong nhn t bo v kt qu l t bo s b dit vong. Tc ca qu trnh kh trng s tng khi nng ca cht kh trng v nhit ca nc tng, ngoi ra cn ph thuc vo hm lng cc tp cht khc trong nc, nng cc tp cht trong nc cao th hiu qu ca qu trnh kh trng s gim i ng k. Hiu qu kh trng ph thuc vo nng cht kh trng, tc nng HClO. Trong k thut x l nc cht dit trng c dng ph bin nht l clo v cc hp cht ca clo v r. d kim v qun l vn hnh n gin.1. Dng ozone kh trng Ozon (O3) l cht kh mu lam nht (trong iu kin nhit v p sut tiu chun),c mi hc c trng.Ozone c tnh hot ha mnh hn Clo, nn kh nng dit trng mnh hn Clo rt nhiu ln. Thi gian tip xc rt ngn do din tch b mt thit b gim, khng gy mi v kh chu trong nc k c khi trong nc c cha phnol.1. Kh trng bng phng php nhit y l phng php kh trng c truyn. un si nc nhit 100oCc th tiu dit phn ln cc vi khun c trong nc. Ch tr nhm vi khun khi gp nhit cao s chuyn sang dng bo t vng chc. Tuy nhin, nhm vi khun ny chim t l rt nh. Phng php un si nc tuy n gin, nhng tn nhin liu v cng knh, nn ch dng trong quy m gia nh. Kh trng bng tia cc tm (UV) Tia cc tm l tia bc x in t c bc sng khong 4 400 nm, c tc dng dit trng rt mnh. Dng cc n bc x t ngoi, t trong dng chy ca nc. Cc tia cc tm pht ra s tc dng ln cc phn t protit ca t bo vi sinh vt, ph v cu trc v mt kh nng trao i cht, v th chng s b tiu dit. Hiu qu kh trng ch t c trit khi trong nc khng c cc cht hu c v cn l lng. St trng bng tia cc tm khng lm thay i mi, v ca nc.1. Kh trng bng siu m Dng siu m vi cng tc dng khng nh hn 2W/cm2 trong khong thi gian trn 5 pht c kh nng tiu dit ton b vi sinh vt trong nc.1. Kh trng bng ion bc Ion bc c th tiu dit phn ln vi trng c trong nc. Vi hm lng 2 10ion g/l c tc dng dit trng. Tuy nhin, hn ch ca phng php ny l: nu trong nc c mu cao, c cht hu c, c nhiu loi mui,th ion bc khng pht huy c kh nng dit trng.

2.3 La chn phng n x l xut phng n x l Vic la chn cng ngh x l nc ph thuc vo cht lng v c trng ca ngun nc th. Cc vn cn cp n khi thit k h thng x l nc bao gm cht lng nc th, yu cu v tiu chun sau x l. Da vo cc s liu c, so snh cht lng nc th v nc sau x l quyt nh cn x l nhng g, chn nhng thng s chnh v cht lng nc v a ra k thut x l c th. Theo cht lng nc ngun c a ra cc phng n x l:Phng n 1:

B cha nc schgin maviB trnB lng li tmB lc nhanhClorineX cn ra h nn bnNc t trm bm ging khoanH thng phn phiTrm bm cp 1Trm bm cp 2 Tm li h thng x l ca nh my bao gm: Gin ma B trn ng B phn ng c lp cn l lng B lng ngang B lc nhanh B cha nc sch2.4 Thuyt minh quy trnh cng ngh u tin, nc ngm c ht t t ln nh h thng bm cp 1, s dn nc vo cng trnh lm thong. Vi mc ch chnh l kh CO2, ha tan oxi t khng kh vo nc oxi ha Fe2+ thnh Fe3+, Mn2+ thnh Mn4+ (nu c) d dng kt ta, d dng lng ng kh ra khi nc nng cao cng sut ca cc cng trnh lng v lc. Sau khi lm thong nc tip tc s qua b lng li tm Nc cn x l vo ng trung tm ca b, ri c phn phi vo vng lng Trong vng lng nc chuyn ng chm dn t tm b ra ngoi v t di ln trn. y, cn c lng xung y, nc trong th c thu vo mng vng v theo ng ng sang b lc. Sau nc c a qua b lc nhanh. Ti y, khng ch gi li cc ht cn l lng trong nc c kch thc ln hn cc l rng to ra gi cc ht m cn lc gi li keo st,keo hu c gy c, mu. K tip l nc c dn vo b cha nc sch, vi ha cht kh trng l dung dich Clo loi tr vi sinh vt tn ti trong nc ngm. Nc c kh trng c a qua b cha nc sch. Cui cng nh h thng bm cp 2 phn phi nc cho ngi dn s dng.

CHNG 3TNH TON CNG TRNH N V3.1 TNH GIN MA3.1.1. Cu to: gm cc b phn sau: H thng phn phi nc. Sn tung ma. H thng thu, thot kh v ngn nc. Sn v ng thu nc.3.1.2 Chc nng: lm giu oxy cho nc v kh kh CO2 c trong nc. gin ma c kh nng thu c oxy ha tan bng 55% lng oxy bo ha v kh c khong 70%-80% lng CO2 trong nc ngm. Nhng lng CO2 sau lm thong khng c xung thp hn 5-6 mg/l3.1.3 Tnh ton kim sau lm thong: K = K0 0,036.Fe2+ = 5,5 0,036.26 = 4,564 (mg/l)Trong : K0: l kim ban u ca nc ngun K0 = 5,5mgl/lFe2+: hm lng st ban u ca nc ngun Fe2+ = 26mg/l Lng CO2 sau lm thong:CO2 = (1-a).CO20+ 1,6.Fe2+ = (1-0.8).160 + 1,6.26 = 73,6 mg/la: hiu qu kh CO2 ca cng trnh lm thong ta chn a = 0,8 i vi lm thong bng gin ma (a = 0,75 0,8)CO20: hm lng CO2 ban u ca nc ngun = 160 PH ca nc ngn sau lm thong

Trong :K: kim sau lm thongC: hm lng CO2 sau lm thong: lng ion ca dung dch = 0,000022.P = 0,000022.300 = 6,6.10-3P: tng hm lng mui = 300Ki: hng s phn ly bc 1 ca axit cacbonnic nhit 200c, tra bng ta c Ki = 4,05.10-725% lng CO2 sau lm thong = 0,25.73,6 = 18,4mg/l25% lng kim sau lm thong = 0,25.4,564 = 1,141mgl/l Da vo 25% lng CO2 v kim va tnh c tra biu (5-1) ta c pH = 6.81pH 6,8 ; kim 1mgl/l t yu cu nn ta dng lm thong t nhin bng gin ma kh st. Din tch mt bng gin ma

Vi : Q:lu lng nc cn s l, Q = 40000 m3/ngy = 1667 m3/h Qm: cng ti ( ly t 10 15 m3/m2.h) chn qm = 12 m3/m2.h

Din tch mi ngn gin ma: Vi: N: s ngn gin ma, chon N= 3 F: din tch mt bng gin ma

Chn kch thc mt bng mi ngn gin ma l: L B = 8m 6m. Din tch hu ch ton b gin ma l: 3 (86) = 144 m2 H thng phn phi nc: vic tnh ton h thng phn phi nc ln gin ma ging nh h thng phn phi nc c tr lc ln b lc nhanh. B tr mi ngn gin ma c 1 ng dn nc chnh ng knh 450 mm, vn tc nc trong mi ng dn nc chnh l:

(theo quy phm vn tc ny nm trong khong t 0,8 1,2 (m/s) Trn ng dn nc chnh ln ngn gin ma, ta b tr cc ng phn phi chnh. Chn khong cch gia cc ng phn phi chnh l 1,3m. S ng phn phi chnh trn mt ngn gin ma l 5 ng. ng phn phi chnh c chiu di bng chiu rng ca gin ma l 6 m. trn cc ng chnh ny c ni cc ng nhnh theo hnh xng c. Lu lng nc vo mi ng phn phi chnh l:

theo quy phm vn tc trong mi ng phn phi chnh t 1 1,2 m/s Ta chn vn tc trong ng phn phi chnh vc =1,1 m/s. ng knh ng phn phi chnh l:

chn dc =200(mm) Kim tra li vn tc trong mi ng phn phi chnh l:

(nm trong khong cho php) Chn khong cch gia cc ng nhnh l 0,3m (theo quy phm t 0,25 0,3 m). s ng nhnh trn 1 ng phn phi chnh l:

( ng) Lu lng vo mi ng nhnh l:

Theo quy phm vn tc trong mi ng nhnh t 1,8 2 m/s. ta chn vn tc trong Zphn phi chnh, chn t l ny l 30%. Tng din tch l phun l:

Theo quy phm ng knh l phun ma t 10 12 mm, chn ng knh l phun ma l 10mm. s l phun ma trn ng nhnh l:

S l(l) Cc l c b tr so le nhau hai bn thnh ng nhnh Chn s sn tung l 3, v hiu qu hot ng ca 3 sn tung u tin thng l cao cn cc sn k tip thng rt km. Khong cch gia cc sn tung cng cao th thi gian tip sc tip xc khng kh cng ln, khang cch ny cng lm nh hng n vic lm v sinh sau ny (chiu cao cng ln cng d lm v sinh) v c bit n nh hng n hiu qu kh CO2 so vi hiu qu ha tan O2 (khong cch cng ln th hiu qu kh CO2 cng cao). Chiu cao hiu qu i vi gin ma l 2m. ( theo cc ti liu tham kho) nhng nu khong cch gia cc sn tung ln th hiu qu kh CO2 cng khng tng ln bao nhiu m li rt tn chi ph xy dng. chn khong cch gia cc sn tung l 0,7 m. chiu cao phn lm thong l: 3 0,7 = 2,1 m. Chn sn tung l cc tm inox c kch thc 1m 1m.vy cn phi s dng 144 tm inox cho 1 sn tung. ng knh l trn sn tung c kch thc cng nh, s lng cng nhiu th hiu qu kh CO2 v ha tan O2 cng cao. Nhng khi mt l cng dy th khng kh s kh khuch tn vo trung tm gin ma, nn hiu qu s l s gim i. Chn ng knh l l 10mm v bc l 50mm, nh vy trn mi tm inox cn phi khoan 2020 = 400 l. H thng thu, thot kh v thu nc: c th thu oxy kh tri kt hp vi vic ui CO2 / ng thi m bo nc khng bn ra ngoi, ta b tr ca chp lm bng b tng ct thp. Gc nghing gia cc chp mt phng nm ngang l 45. Khong cch gia hai ca chp k tip nhau l 0,2m v chiu rng mi ca l 0,2m. ca chp c b tr xung quanh trn ton b chiu cao ca gin ma, ni c b mt tip xc vi khng kh. Cc ca chp ny c xy dng cch mp ngoi ca sn tung l 0,6m. khong cch ny c lm li i xung quanh khi lm v sinh gin ma. H thng thu nc v x cn gin ma: sn thu nc t di y gin ma c dc 0,04 v ng dn nc qua b trn. B tr 3 ng thu nc( mi ngn 1 ng) c t y sn thu nc v cao hn sn thu t nht 0,2m ngn cn bn khng theo dng nc vo cc cng trnh pha sau. Theo quy phm vn tc nc trong ng ly t 1 1,5 m/s. chn vn tc ny l v=1,2m/s. ng knh ng dn nc l:

chn D = 450(mm) Kim tra li vn tc trong mi ng phn phi chnh l:

(nm trong khong cho php)i vi ng x cn chn ng thp c ng knh d = 150mm (theo quy phm ly t 100 200 mm). mi ngn c 1 ng x cn. b tr ng x cn gia sn v st sn thu nc (pha y thp). c gin ma c 3 ng x cn.Kim tra thi gian lm thong: c tnh s b theo thi gian ri ton b trn chiu cao phn lm thong (b qua thi gian nc ng trn cc sn tung):

chiu cao gin ma: H = h1 + h2 + h3 +h4Vi:h1: chiu cao h thng phn phi nc, h1 = 0,75m.h2: chiu cao h thng lm thong, h2 = 2,1m.h3: chiu cao sn thu nc, h3 = 0,75m.h4: chiu cao t mt t n y sn thu nc, h4 = 5,4m

H = 0,75 +2,1+0,75+5,4= 9m. Ngoi cc b phn chnh trn th gin ma cn c b tr cc vi nc vi ng knh 20mm ra gin ma. C khong 10m b tr 1 vi ra sn tung nc. Tn tht thy lc qua gin ma : do nc ri t do trn dn na nn ta chon s b tn tht thy lc ca nc qua gin ma l 0,5

3.2.TNH B TRN B trn ng c nhim v trn u nc v ha cht. i vi h thng x l ny s s dng vi nn ta s dng loi b trn ng. Xy dng ti thiu 2 b trn ng phng khi c s c hoc 1 b cn sa cha h thng x l vn tip tc hot ng.ch b trn ng l loi b c mt bng hnh vung v loi ny s d xy dng hn loi b c mt bng hnh trn. Cng sut: 40000m3/ng = 1667 m3/h =0,46 m3/s Din tch m bng ca ca b trn tnh theo vn tc nc dng l 25mm/s =0,025m/s (theo iu 6.56 TCVN 33:2006) Khi

Chn mt bng ca b l hnh vung c kch thc: 4 x 4 (m2)bt = 4 (m) Kim tra li vn tc nc dng trong b:

Chn vn tc nc trong ng dn nc ngun y b: v = 1,5m/s

Chn d = 600mm Din tch y (ch ni vi b ) l :

Do din tch y b( ch ni vi ng)

Chn gc hnh chp y , chiu cao phn hnh chp

Chn hd = 3,2 (m)Trong : bt: b rng ca b = 4 (m)b: b rng ng dn nc vo = 0,65 (m) Th tch phn hnh chp ca b trn

Trong ft : din tch b mt ca b trnfd :din tch phn y ca b trn (ch ni vi ng dn nc vo) Th tch ton phn ca b vi thi gian lu nc trong b l 2 pht

Th tch phn trn (hnh hp) b trn:

Chiu cao phn trn ca b

Chn chiu cao bo v: hbv=0,3m Chiu cao ton phn ca b :

Chn vn tc nc t b trn sang b lng l 0,8 m/s (theo quy phm vn tc ny nm trong khong 0,8 - 1 m/s)din tch mng thu xung quanh b trn l :

Chn mng thu nc c din tch: rng x cao :0,54 x 0,54 m. Chn chiu cao sn cng tc cch mt b trn cng nh cch mt mng thu nc 0,3 mng knh ng dn nc t b trn sang b lng l:

Chn ng c ng knh 600 mm. Kim tra vn tc nc chy trong ng :

(nm trong khong vn tc cho php) Thit k thu nc bng mng vng c l ngp trong nc. Nc chy trong mng n ch ng dn nc ra khi b theo 2 hng ngc chiu nhau nn lng nc ca mng thu nc l

Din tch tit din mng vi tc nc chy trong mng vm=0,6m/s (Theo iu 6.56 TCVN 33:2006)

Chn chiu rng mng bm=0,3 Chiu cao lp nc tnh ton trong mng

Chn Hm =0,3m Q = 0,46 m3/s chn ng dn sang b phn ng d = 400 mm vi v = 0,9 m/s (Theo TCVN 33:2006,iu 6.59 v m/s) Kim tra thi gian lu nc trong b trn:Th tch b trn:

Thi gian lu nc trong b trn:

(pht) Tn tht thy lc qua b trn:

Trong : H: tn tht thy lc qua b trn G: gradien tc i vi b trn thy lc chn G = 300l/s: nht ng hc ca nc .Chn nht ng hc ca nc 250C, = 0,85 (m2/s)V : th tch b trn, V = 28 (m3)

Q : lu lng nc qua b trn, g : gia tc trng trng ,g = 9,81 (m/s2)3.3 B lng li tm 3.3.1 Nguyn tc lm vic: Nc cn x l vo ng trung tm ca b, ri c phn phi vo vng lng. Trong vng lng nc chuyn ng chm dn t tm b ra ngoi v t di ln trn. y, cn c lng xung y, nc trong th c thu vo mng vng v theo ng ng sang b lc.So vi mt s kiu b lng khc, b lng li tm c mt s u im sau: nh c thit b gt bn, nn y c dc nh hn so vi b lng ng, do chiu cao cng tc ca b nh, thch hp xy dng nhng khu vc c mc nc ngm cao. B va lm vic va x cn lin tc nn khi x cn b vn lm vic bnh thng.3.3.2 Tnh ton -Din tch b mt b xc nh theo cng thc:

(m2)Trong :Q: lu lng x l, Q = 1667 m3/giU0: tc lng cn tnh ton, uo = 0.5 ( uo = 0.4 1.5mm)F : Din tch vng xoy ca b lng, y l phn din tch nm gia b do chuyn ng xoy ca dng nc, cn khng lng xung c: f = .rx2 (m2)rx: bn knh vng xoy, rx = rp + 1rp: Bn knh ngn phn phi nc hnh tr, chn rp = 2 m ( qui phm 24 m) rx = rp + 1 = 2 + 1 = 3 m f = .rx2 = 3,1432 = 28.25 m2

Vy m2 Bn knh ca b l:

vy D = 40 (m) Chn chiu su ti thnh b l h = 2 m Chn dc y b l: i= 0,06 ( qui phm 5 8 %) Chiu cao ca b lng s l:

H = h + i.R = 2 + 0.0620 = 3.2 m Chn chiu cao bo v l 0,3m

Tnh ngn phn phi nc: Ngn phn phi nc c thit k hnh tr c khoan l trn vch ngn, mp di vch ngn ngp di mc nc trong b su bng chiu su b lng ti thnh b (h = 2 m) Din tch xung quanh ca ngn phn phi l:

fp = .d.h = 3,1442 = 25,12 m2 trong : d l ng knh ngn phn phi, d = 2rp = 4m Tng din tch cc l trn vch ngn:

(m2) ( ly vl = 1 m/s) Chn ng knh l dl = 40 mm (qui phm 36 40mm), fl = 0,00138 m2 S l: l Xp thnh 6 hng ngang so le nhau, mi hng 56 l Khong cch gia cc tm l theo chiu ng:e = h6 = 20006 = 333 mm chu vi ngn phn phi:

l = 2rp = 23,142 = 12.56 (m) Khong cch gia cc tm l theo chiu ngang:

(mm) T s din tch cc l vi din tch b mt xung quanh ngn phn phi nc:

Mng thu nc: Nc c thu bng mng vng quanh thnh ngoi b. Chiu di mng thu nc: Chiu rng mng thu nc bng 10% ng knh b:

Chn chiu cao mng thu hm = 0.5 m. dc ca mng v pha ng tho nc ra I = 0.02.

Mng rng ca: Mng rng ca c gn vo mng thu nc (qua lp m cao su) iu chnh cao mp mng thu m bo thu nc u trn ton b chiu di mng trn. B dy mng rng ca l 5 mm Chiu cao tng ca mng rng ca 250mm. Chiu di mng rng ca bng chiu di mng thu nc: l = lm = 125.6 (m). Mng rng ca x kh thu nc ch V, gc 90o iu chnh cao mp mng: Chiu cao khe: 50 mm. B rng mi khe l 100 mm. Khong cch gia cc nh l 100mm Mng rng ca c bt dnh vi mng thu nc b tng bng bulng qua cc khe dch chuyn. Khe dch chuyn c ng knh 10 mm, bulng c bt cch mp mng rng ca 50mm v cch y ch V l 50mm. hai khe dch chuyn cch nhau 0.5m, Thanh gt bn: Chiu di: l = 90%D = = 36 (m). Nng lng cn truyn vo nc:P = G2 V

Trong :G : cng khuy. G = 30 s-1V : th tch b . V = 3285 (m3) : nht ng lc bn. = 0,00105 (N.s/m2)

P = 302 3285 0,00105= 3104 (J/s) = 3.104 (Kw) Xc nh s vng quay ca cnh gt bn:

N = = = 0.003 ( vng/s) = 0.18 vng/pht

3.5.TNH B LC NHANH. Din tch b lc nhanhF = Trong Q: Cng sut trm (m3/ng). Q = 40.000m3/ngT: Thi gian lm vic. T = 24 hvbt: Tc lc ch bnh thng. vbt = 6 m3/ha: S ln ra b trong ngy m. ch bnh thng a = 2W: Cng nc ra lc. W = 14 l/s.m2

t1 : Thi gian ra lc. t1 = 6pht =ht2: Thi gian ngng b lc ra. t2 = 0,35 h.

F = Trong b lc, chn ct lc c c ht dtd = 0,7 0,8 mm, h s khng ng nht K= 2 ; Chiu dy lp ct lc 0,8m. S b lc cn thit: bChn N = 8 b Kim tra li tc lc tng cng vi iu kin ng 1 b ra:

Theo TCVN 33:2006: Vtc=m bo yu cu Din tch mt b lc l: Chn kch thc b l: L . B = 4,5 x 8 = 36,9( m2) Chiu cao ton phn ca b lc nhanh

H = hd + hv + hn +hl+ hbvhd: chiu cao lp si hd = 0,7 mhv: chiu dy lp vt liu lc hv = 0,8 mhn: chiu cao lp nc trn lp vt liu lc hn = 2 m ( 2 m)hdl: chiu dy an vt liu lc hdl= 0,1mhp: chiu cao bo v= 0,5 mH = 0,7 +0,8 + 2 +0,4+0,1= 4 m Xc nh h thng phn phi nc ra lc: Lu lng nc ra ca 1 b lc:

Chn tc nc chy trong ng dn theo quy phm l v = 2m/s (TCVN Theo 33:2006: v = 1,5 - 2 m/s) Tit din ng dn nc n b lc l:

Sra = ng knh ng dn nc n b ra lc l:

Chn ng dn nc ra c ng knh 600mm. Kim tra li vn tc nc chy trong ng dn nc chnh:

v = Ly khong cch gia cc ng nhnh l 0,3 m th s ng nhnh ca 1 b lc l:

(ng nhnh) Ly n = 52 (ng nhnh) Lu lng nc ra lc chy trong mi ng nhnh:

Chn ng knh ng nhnh dn = 75 mm bng thp th tc nc chy trong ng nhnh l:vn = 2(m/s)

Tng din tch l ly bng 35% din tch tit din ngang ca ng, tng din tch l tnh c l :

Ch l c ng knh 12 mm , din tch l s l :

Tng s l s l: l S l trn mi ng nhnh s l :(l) Trn mi ng nhnh, cc l xp thnh hai hng so le nhau, hng xung pha di v nghing 1 gc 450 so vi mt phng nm ngang, s l trn mi hng ca ng nhnh l: 19/2 = 10 (l) Khong cch gia cc l s l:

(0,525 : ng knh ngoi ca ng gi chnh(m))

Tnh nh h thng dn gi ra lc Chn cng gi l: Wgi = 15 m/s th lu lng gi tnh ton l:

Ly tc gi trong ng dn gi chnh l 17 m/s ( m/s) ng knh ng gi chnh nh sau:

S ng nhnh ly bng 32 ng Lng gi trong 1 ng s l :

ng knh ng gi nhnh l : ng knh ng gi chnh l 200mm din tch mt ct ngang ca ng gi chnh s l :

Tng din tch cc l ly bng 40% din tch tit din ngang ng gi chnh (quy phm l 35 - 40%) gi= 0,4 x 0,0314=0,01256m2 . Chn ng knh l gi l 3mm (quy phm l 2 5 mm) din tch 1 l 1 l gi l:

fl gi

tng s l gi s l : (l) s l trn 1 ng gi nhnh l: (l) Khong cch gia cc l: (0,22 : ng knh ngoi ca ng gi chnh; l gi trn mi ng nhnh t thnh hai hng so le v nghing 1 gc 450 so vi trc thng ng ca ng ) Tnh ton mng phn phi v thu nc ra lc B c chiu rng l 4 m. Chn mi b b tr 2 mng thu nc ra lc c y hnh tam gic. Khong cch gia cc tim mng l d = 4/2 = 2 m (Theo TCVN 33:2006: d 2,2m) Lng nc ra thu vo mi mngqm = Wn.d.l (l/s) Trong :Wn = 14 l/s.m3( cng ra lc)d: khong cch gia cc tim mng , d = 2(m)l: chiu di ca mng l = 7 mqm = 14 x 2 x 8 = 224 (l/s) = 0,224(m3/s) Chiu rng mng tnh theo cng thc

Trong :qm: lu lng nc ra tho qua mnga: t s gia chiu cao phn ch nht vi chiu rng mng, ly a =1k: h s i vi tit din mng hnh tam gic k = 2,1 Chiu cao phn mng hnh ch nht l:

Vy chn chiu cao mng thu nc l hcn = 0,3m chiu cao ca y tam gic dc ca mng ly v pha mng nc tp trung l i = 0,01; chiu dy thnh mng l m = 0,08 m. Chiu cao ton phn ca mng thu nc raHm = hcn + hd + m = 0,3 + 0,2 + 0,08 = 0,58 (m) Khong cch t b mt lp vt liu lc n mp trn mng thu nc xc nh theo cng thc:Trong L: chiu cao lp vt liu lc L = 0,8 me: gin n tng i lp vt liu lc (bng 4-5) e = 45% Theo quy phm khong cch gia y di cng ca mng dn nc ra phi nm cao hn lp vt liu lc ti thiu 0,07 m. Chiu cao ton phn ca mng thu nc l: Hm = 0,68 m V mng dc v pha mng tp trung i = 0,01, mng di 8 m

Chiu cao mng tp trung l: 0,68 + 0,018 = 0,76 (m)Vy Hm s phi ly bng: Hm = 0,07 + 0,76 = 0,83 (m) Nc ra lc t mng thu nc tp trung. Khong cch t y mng thu n mng tp trung xc nh theo cng thc

Trong :

qm: lu lng nc chy vo mng tp trung nc qm = 0,462 = 0,92m3/s

: chiu rng ca mng tp trung = 0,7m (Theo TCVN 33:2006: chiu rng mng tp trung khng nh hn 0,6 m)g = 9,81 m/s2 gia tc trng trng

Tnh ton s chp lc S dng loi chp lc c ui di, c khe rng 1mm Chn 36 chp lc trn 1m2 sn cng tc (Theo TCXDVN 33:2006) Tng s chp lc trong mt b l: (ci) Lu lng nc i qua 1 chp lc

Lu lng gi i qua 1 chp lc

Tn tht p lc qua chp lc:

Trong V: tc chuyn ng ca nc hoc hn hp nc v gi qua khe h ca chp lc ( ly khng nh hn 1,5m/s)

: h s lu lng ca chp lc. i vi chp lc khe h =0,5 Tnh tn tht p lc khi ra b lc nhanh Tnh tn tht p lc trong h thng phn phi bng gin ng khoan l:

Trong :V0:tc nc chy u ng chnh ; v0 = 1,91 (m/s)Vn: tc chy u ng nhnh; vn = 1,99(m/s)g: gia tc trong trng; g =9,81 (m/s2)

; h s sc cn ;

Tn tht p lc qua lp si : Ls: chiu dy ca lp si : 0,8 mW: cng ra lc W = 14 (l/s.m2)

Tn tht p lc trong lp vt liu lc

ng vi kch thc ht d= mm; a = 0,76; b = 0,017(X l nc cp Nguyn Ngc Dung)e: gin n tng i ca lp vt liu lc e = 0,45L: chiu dy lp ct lc L = 0,8hvl = (0,76 + 0,017.14).0,8.0,45 = 0,359 m p lc ph v kt cu ban u ca lp ct lc ly hbm = 2 m Vy tn tht p lc trong ni b b lc:

chn my bm ra loc v bm gi ra lc :p lc cng tc cn thit ca my bm ra lc xc nh theo cng thc:

Trong : Ht = 8,5 (m) Hhh :l cao hnh hc t ct mc nc thp nht trong b cha n mp Mng thu nc ra (m)

4: chiu su mc nc trong b cha (m)3,5 : chnh mc nc gia b lc v b cha (m)2: chiu cao lp nc trong b lc0,71 : khong cch t lp vt liu lc cho n mng (m)H : tn tht p lc trn ng ng dn nc t trm bm nc ra n b lc (m) Gi s chiu di ng dn nc ra lc l l = 100(m). ng knh ng dn nc ra lc D = 500(mm), Qr = 517 (l/s). Tra bng c 1000i = 16,3. Vy h = i.l = 0,0163 x 100 =1,63(m) Hcb: tn tht p lc cc b cc b phn ni ng v van kha xc nh theo cng thc :

Gi s trn ng ng dn nc ra lc c cc thit b ph tng nh sau: 2 ct 90, 1 van kha , 2 ng ngn.

Vy:

Vi Qr = 517 (l/s), Hr = 17,14 (m) chn my bm ra lc ph hp.Ngoi 1 my bm ra lc cng tc, phi chn 1 my bm d phng. Vi Qgio =0,554(m3/s), Hgio = 3 (m) th s chon dc my bm ph hp. T l lng nc ra so vi lng nc vo b loc tnh theo cng thc :

Trong : (gi)

(gi) Tnh bm nc ra lc p lc cng tc cn thit ca my bm ra lc xc nh theo cng thc: Hr = hhh + ho+ht+ hcb hhh: cao hnh hc t ct mc nc thp nht trong b cha n mp mng thu nc ra (m)

hhh = 4 + 3,5 2 + 0,61 = 6,11 m4: chiu su mc nc trong b cha (m)3,5: chnh lch mc nc gia b lc v b cha (m)2: chiu cao lp nc trong b lc (m)0,61: khong cch t lp vt liu lc n mp mng (m)ho: tn tht p lc ng ng dn nc t trm bm nc ra n b lc (m) Gi s chiu di ca ng dn nc ra lc l = 100 m, ng knh ng ra lc d=500m; Qr = 196 l/s; 1000i = 32,8

ho = il = 0,0328 mhcb: tn tht p lc cc b ni ni ng v van kho

Gi s trn ng ng dn nc ra lc c: 2 ct 900, 1 van kho, 2 ng ngnHcb = 0,8 (m) Hr = 6,21 + 3,28 + 8,5 + 0,8 = 18,8(m) Cng sut bm = 100 kW : hiu sut chung ca bm, = 0,7Chn bm ra lc c cng sut 100 kW, vi lu lng l 1411 m3/h v ct p l 18 m

Tnh bm kh ra lc Bm kh dng ra lc c tnh ton da trn cc yu cu sau: Ct p ca bm c tnh theo cng thcH = h1 + h2 + h3Trong :h1: ct p khc phc tn tht p lc chung trong ng dn kh tnh t my thi kh n b lc.h2: ct p khc phc ct nc v lp ct lc trn l phn phi gih3: ct p khc phc tn tht t h thng phn phi n mp mng thu nc ra lcChn h1 = 1 mTnh h2: h2 = H1 + H2

Vi: l trng lng ring ca ct H1 l chiu cao lp ct H2 l chiu cao lp nc t mt lp vt liu lc n mp mngTa c = 2,6, H1 = 0,8 m

H2 = 0,8 m

h2 = 2,6 0,8 + 0,8= 2,88 m Chn h3bng chiu cao lp nc t ng phn phi n mp mng thu nc ra, h3 = 2 m

vy ct p cn thit ca bm gi ra lc l:H = 1 + 2,88 + 2 = 5,88 m Chn bm kh ra lc c ct p l 6 m, vi lu lng l 0,5 m3/s B thu hi nc ra lc ng thu nc r lc t b cha ra ng xi phng ng tm: Lu lng thu nc lc ca 1 b l: ng knh ng t 1 b ra xi phng ng tm, chn d = 0,15m Vn tc nc chy trong ng:

Thit b xi phng: ng knh ng xi phng ng tm: Nc qua xi phng ra mng cha nc sch, t nc c dn v b cha ng dn nc ti b cha Vi v = 1m/s, q = 0,097m3/s, chn d = 350mm

3.6. CNG TRNH TI VI Th tch b ha trn: Kch thc r ti vi:

Trong mr:lng vi cha trong r(thng t 50 80kg)

: khi lng ring ca vi,1200kg/m3 Lng vi nguyn cht cho vo nc l 50mg/l Liu lng th trng cn dng ly bng 1,25 ln lng vi nguyn cht. Nn lng vi th trng cn dng: Lng vi cn thit trong 1gi:

Chn khong cch gia 2 ln ha trn l 8h Lng vi cn dng trong 8h:

S r cn thit cho 1 ln ha trn:

(r) R c lm bng thp khng r, y r c an bng li thp 5 x 5 mm. Thi gian ti 1 m l 10 pht, thi gian a vi vo l 5 pht. Vy mi m ti cn 15 pht. Sau 3 ln ti nn x cn trong r ra ngoi. Thi gian cn ti ht 7 r vi:t = 7 x 15 = 105 pht = 1,75 gi3.7 KH TRNG NC Liu lng clo kh trng ly bng 1mg/l =10-3kg/m3(Theo TCVN 33:2006: lng clo 0,7 1 mg/l) Lng clo cn dng trong 1 gi

Trong :Q: Lu lng nc x l (m3/h) a: liu lng clo hot tnh (ly theo tiu chun TCVN 33:2006). Lng nc tnh ton cho clorator lm vic ly bng 0,6 m3 cho 1kg clo (Theo TCXDVN 33:2006) Lu lng nc cp cho trm clo:

ng knh ng nc

Chn ng knh ng d = 10 (mm) Liu lng clo cn thit dng kh trng trong mt ngy l:

Lng clo d tr dng trong 30 ngym = 30 x 8,4 = 252 (kg) ng knh ng dn clo

Lu lng giy ln nht ca clo lng

(m3/s) Vn tc ng ng: v = 0,8m/s(theo TCVN 33:2006)

Vy =26mm