n Qu trnh & Thit b - Sy thng quay CBHD: Thy Mai Thanh Phong

MC LCMC LC1PHN I: TNG QUAN TI LIU31.SY32.THIT B SY THNG QUAY53.NGUYN VT LIU - MUI N6PHN 2: QUY TRNH CNG NGH7PHN 3: TNH TON THIT B71.TNH TON CN BNG VT CHT V NNG LNG81.1.Cc thng s ca tc nhn sy81.2.Tnh ton cn bng vt cht91.3.Tnh ton cn bng nng lng102.TNH THI GIAN SY133.TNH TON THIT B CHNH143.1.Tnh kch thc thng quay143.2.Thi gian lu143.3.Kim tra tc quay ca thng143.4.Kim tra vn tc tc nhn sy143.5.Tnh b dy cch nhit ca thng153.5.1.H s cp nhit t dng tc nhn sy n thnh trong ca thng 1153.5.2.H s cp nhit t thnh ngoi ca thng sy n mi trng xung quanh 2:163.5.3.H s truyn nhit K183.5.4.Tnh b mt truyn nhit F183.5.5.Tnh hiu s nhit trung bnh gia tc nhn sy v khng kh bn ngoi ttb183.5.6.Tnh lng nhit mt mt ra xung quanh193.6.Kim tra b dy thng193.7.Tnh tr lc qua thng sy213.8.Tnh chn cnh o trn214.THIT K B PHN TRUYN NG234.1.Chn ng c234.2.Chon t so truyen ong234.3.Tnh bo truyen banh rang245.TNH VANH AI276.TNH CON LAN 287.TNH CON LAN CHAN298.TNH TON THIT B PH298.1.Calorifer298.2.Cyclone328.3.Tnh ton kh ng v chn qut gi338.3.1.Tnh tr lc h thng ng ng338.3.2.Tnh cng sut v chn qut38PHN 4: KT LUN40PHN 5: TI LIU THAM KHO40

PHN I: TNG QUAN TI LIU1. SY Qu trnh syTrong cng ngh ha cht, thc phm, qu trnh tch nc ra khi vt liu (lm kh vt liu) l rt quan trng. Ty theo tnh cht v m ca vt liu, mc lm kh ca vt liu m thc hin mt trong cc phng php tch nc ra khi vt liu sau y: Phng php c hc (s dng my p, lc, ly tm). Phng php ha l (s dng canxi clorua, acid sunfuric tch nc). Phng php nhit (dng nhit bc hi m trong vt liu).Sy l qu trnh dng nhit nng lm bay hi nc ra khi vt liu rn hay lng. Nhit cung cp cho vt liu m bng cch dn nhit, i lu, bc x hoc bng nng lng in trng c tn s cao. Mc ch ca sy l gim bt khi lng vt liu, tng bn vt liu, bo qun tt trong mt thi gian di, nht l i vi lng thc, thc phm.Qu trnh sy khng ch l qu trnh tch nc v hi nc ra khi vt liu mt cch n thun m l mt qu trnh cng ngh. N i hi sau khi sy vt liu phi m bo cht lng cao, tiu tn nng lng t v chi ph vn hnh thp. Trong qu trnh sy, nc c bay hi nhit bt k do s chnh lch m b mt vt liu v trong lng vt liu, gia b mt vt liu v mi trng xung quanh. C cc hnh thc sy: Sy i lu Sy rang Sy bc x Sy thng hoaDo iu kin sy trong mi trng hp sy khc nhau nn c nhiu kiu thit b sy khc nhau, v vy c nhiu cch phn loi thit b sy: Da vo tc nhn sy: ta c thit b sy bng khng kh hoc thit b sy bng khi l, sy bng cc phng php c bit nh sy thng hoa, sy bng tia hng ngoi hay bng dng in cao tn. Da vo p sut lm vic: thit b sy chn khng, thit b sy p sut thng. Da vo phng php cung cp nhit cho qu trnh sy: thit b sy tip xc, thit b sy i lu, thit b sy bc x Da vo cu to thit b: phng sy, hm sy, sy bng ti, sy trc, sy thng quay, sy tng si, sy phun Da vo chiu chuyn ng ca tc nhn sy v vt liu sy: cng chiu, ngc chiu v giao chiu. thc hin qu trnh sy, ngi ta phi s dng h thng gm nhiu thit b nh: thit b sy (bung sy, hm sy, thp sy, thng sy,), thit b t nng, tc nhn sy hoc thit b lnh lm kh tc nhn sy, qut, bm v mt s thit b ph khc nh bung t, cyclon Chng ta gi h thng cc thit b thc hin mt qu trnh sy c th no l mt h thng sy. Tc nhn syTc nhn sy l mi trng cp nhit cho vt liu v tch m, gm c: khng kh m, khi l, hn hp khng kh hi v hi nc, hi qu nhit. Tc nhn sy c nhim v sau: Gia nhit cho vt sy Ti m: mang m t b mt vt vo mi trng Bo v vt sy khi b m khi qu nhit.Cc thng s c trng cho tc nhn sy: p sut ring phn ca m PA: PA + Pkkk = P tng PA = Ptng - Pkkk m tng i (%)(%)=100 m tuyt i (hm m) x: lng m trong 1kg khng kh khx = Nhit hm ring (enthalpi) H : lng nhit (kJ) trong 1 kg khng kh khH = Hkkk + .x = t + Nhit bu kh tk Nhit bu t t Nhit im sng ts S chnh lch gia nhit bu kh v bu t l th sy ca khng kh. Khi tk=t th kk bo ha m. Vt liu sy Theo cu trc vt liu m ta chia thnh: Vt liu mao qun xp: l vt liu sau khi sy th dn v d v, khi ht m th khng tr li trng thi ban u c Vt liu keo: khi sy kh b co th tch nu ht m th trng n tr li c tnh n hi Vt liu xp mao qun Tt c vt liu m u c kh nng: Ht m t mi trng xung quanh:Pm< PA Nh m ra mi trng xung quanh: Pm> PA Khi Pm = PA th cn bng ng gia ht v nh Cc thng s c trng cho vt liu sy: Khi lng ring Khi lng xp xp m tng i U (kg m/kg vl t)U= = = m tuyt i U (kg m/kg vl kh)U = = = = Cc yu t nh hng tc sy Bn cht vt liu sy: cu trc , thnh phn ho hc , c tnh lin kt m Hnh dng vt liu sy: kch thc mu sy , b dy lp vt liu din tch b mt ring ca vt liu cng ln tc sy cng nhnh D m u , m cui , m ti hn ca vt liu D m , nhit v tc khng kh Cu to thit b sy , phng thc v ch sy

Cht ti nhitDu FO (hay du mazut) - nhin liu t l - l sn phm ch yu ca qu trnh chng ct thu c t phn on sau phn on gas oil khi chng ct du th nhit si ln hn 350 C. Du mazut l loi nhin liu gm ch yu cc cn ca qu trnh chng ct du th. Loi du ny thng c s dng cho cc ni hi trong cc nh my in, tu, v trong cc nh my cng nghip.

2. THIT B SY THNG QUAYMy sy quay c s dng sy kh cc loi vt liu dng bt hot ht nh m t. My sy quay c cu to hp l, c th thay i nghing v tn sut quay. Nguyn liu m c a vo trong my t pha u cao ca thng quay, my bt u quay trn v cc cnh bn trong lm nhim v o u nguyn liu. Nguyn liu tip xc vi kh nng hon ton v hi m c loi b. Vt liu kh c tho ra u thp ca thng. Kh thi c dn qua cyclone thu hi.

Hnh 1.1: My sy thng quay1 - bung t to tc nhn sy; 2 - b phn np liu vo thng sy; 3 - m kn ming thng; 4,7 - vnh ai ln; 5 - bnh rng; 6 - thng sy; 8 - ca ni vi qut ht kh thi cng h thng cyclon v lc ti; 9 - cnh o; 10 - ca ly sn phm; 11 - cc con ln chn thng sy khng tt; 12,15 - con ln ; 13 - ng c; 14 -hp gim tc v bnh rng dn ng; 16 - hp m kn hnh rng lc.My sy thng quay c nhiu u im nh: My sy quay c c trng bi cng sut ln vi mc tiu th nng lng thp. N c thit k vi c cu hp l, hot ng thn thin vi mi trng, t to nhim. c cung cp vi gi c cnh tranh so vi cc my cng loi, ng thi c hiu sut cao hn. My sy quay vn hnh d dng, hot ng n nh, t l trc trc thp, c bn cao, sy kh c nhiu loi vt liu.

3. NGUYN VT LIU - MUI NMui l mt cht rn c dng tinh th, c mu t trng ti c vt ca mu hng hay xm rt nht, thu c t nc bin hay cc m mui. Mui thu c t nc bin c cc tinh th nh hoc ln hn mui m. Trong t nhin, mui n bao gm ch yu l Natri clorua (NaCl), nhng cng c mt t cc khong cht khc (khong cht vi lng). Mui n thu t mui m c th c mu xm hn v du vt ca cc khong cht vi lng. Mui n l cn thit cho s sng ca mi c th sng, bao gm c con ngi. Mui n tham gia vo vic iu chnh cha nc ca c th (cn bng lng). V ca mui l mt trong nhng v c bn. S thm mui c th pht sinh do s thiu ht khong cht vi lng cng nh do thiu Natri clorua.

PHN 2: QUY TRNH CNG NGH

Hnh 2.1: Quy trnh cng ngh h thng sy thng quay1 - Qut y; 2 - Calorifer; 4 - Thit b chnh (thng quay); 6 - Cyclon; 7 - Qut ht Thuyt minh quy trnh:Khng kh t qut y i vo calorifer v trao i nhit vi khng kh nng t bung t to tc nhn sy. Nguyn liu i t ca np liu. Thng quay s quay trn nh h thng bnh rng v ng c. Nh cnh o trn v tc nhn sy m nguyn liu i t u n cui thng quay, thot ra ngoi bng ca tho liu v c m t yu cu. Khng kh sau khi sy s c ht ra ngoi bng qut ht v i qua cyclone trc lc bi bn.

PHN 3: TNH TON THIT BVt liu sy l mui n vi cc thng s vt l c bn nh sau: m ban u ca vt liu sy (theo vt liu m):1 = 6% = 0,06 m cui ca vt liu sy (theo vt liu m):2 = 2% = 0,02 Khi lng ring ht vt liu:r = 2350 kg/m3(Bng I.1/8 - [1]) Khi lng ring th tch ca vt liu:v = 1020 kg/m3 (Bng I.1/8 - [1]) Nhit dung ring ca vt liu kh:Cvl = 0,712 kJ/kgoK 1. TNH TON CN BNG VT CHT V NNG LNG1.1. Cc thng s ca tc nhn syTc nhn sy l khng kh Trng thi khng kh ngoi tri, c biu din bng im A c (to, o)Tra gin I-d tm ra cc thng s khcA: to = 26oC o = 80% p sut hi bo ha: 0,0335; bar cha m:xo = ; kg m/kg khng kh Enthalpy:Ho = = 70,321; kJ/kg kkkTh tch ring:o = 0,9024 ; m3/kg kkk Khng kh c qut a vo calorifer v c t nng ng m (x1 = xo) n trng thi B (x1, t1). Trng thi B cng l trng thi ca tc nhn sy vo thng sy.B: t1 = 200oC x1 = xo = 0,0174 (kg m/kg kkk)

15,713; barx1 = => 1 = 0,0018H1= = 250,2924; kJ/kg kkko = 1,4289; m3/kg kk Khng kh trng thi B c y vo thit b sy thc hin qu trnh sy l thuyt (H1=H2). Trng thi khng kh u ra ca thit b sy l C (t2, 2).Nhit ca tc nhn sy ra khi thit b sy t2 ty chn sao cho tn tht nhit do tc nhn sy mang i l b nht nhng phi trnh hin tng ng sng, ngha l trnh trng thi C nm trn ng bo ha. ng thi cha m ca tc nhn sy ti C phi nh hn m cn bng ca vt liu sy ti im vt liu sy khng ht m tr li

C: H2 = H1 = 250,2924kJ/kg kkkts 48 oC

= 100%Chn t2 = 70oC 0,3073; barH2= 0,0685 ; kg m/kg kk

0,3276

1,1221 ; m3/kg kkkBng 3.1 - Trng thi tc nhn sy trong qu trnh sy l thuyti lngTrng thi khng kh ban u (A)Trng thi khng kh vo thit b sy (B)Trng thi khng kh i ra khi thit b sy (C)

t (oC)2620070

(n v)0,80,00180,3276

x (kg/kgkk)0,01740,01740,0685

H (kJ/kgkk)70,3211250,2924250,2924

pb (bar)0,033515,71300,3073

v (m3/kgkk)0,90241,42891,1221

1.2. Tnh ton cn bng vt chtTa k hiu cc i lng nh sauG1, G2 (kg/h): Khi lng vt liu sy i vo, i ra thit b1, 2: m tng i ca vt liu sy u vo, ra ca thit b syW(kg/h):lng m bay hi trong 1 giGk(kg/h):Khi lng vt liu kh tuyt i.Phng trnh cn bng vt cht

Lng m bc hi trong 1 giW= G1 = 2000 81,633 (kg/h)Lng vt liu kh tuyt iGk = Gk = 2000 (1 - 0,06) = 1880 (kg/h)Nng sut ca sn phm sy = 2000 - 81,633 = 1918,367 ; kg/hLng tc nhn kh cn thit:

; kg/hLng tc nhn tiu hao ring

; kg kk/kg m1.3. Tnh ton cn bng nng lngQu trnh sy khng c b sung nhit lng, QBS = 0Thit b sy thng quay khng c thit b chuyn ti, QCT = o Nhit lng a vo thit b sy gm: Nhit lng do tc nhn sy nhn c trong calorifer: L(H1 - Ho) Nhit lng do vt liu sy mang vo: [(G1 - W)Cv1 + WCa].tv1 Nhit lng a ra khi thit b sy bao gm: Nhit lng tn tht do tc nhn sy mang i: L(H2 - Ho) Nhit lng tn tht qua c cu bao che: QBC Nhit lng do vt liu sy mang ra: G2.Cv2.tv2 tv1: nhit ban u ca vt liu sy, thng ly bng nhit mi trng: tv1 = to = 26oC tv2: nhit cui ca vt liu sy sau khi ra khi thit b sy:tv2 = t2 - (5 10oC) = 70 - 5 = 65oC Cv1 = Cv2 = Cv: nhit dung ring ca vt liu sy vo v ra khi thit b sy l nh nhau. y, Cv l nhit dung ring ca vt liu sy vi m 2:Cv = Cvl.(1 - 2) + Ca.2, kJ/kg.oKCa: nhit dung ring ca m.Vi m l nc th: Ca = Cn = 4,18 kJ/kg.oK Cv = Cvl(1 - 2) + Ca.2 = 0,712(1 0,02) + 4,18 . 0,02 = 0,7814; kJ/kgoK

Cn bng nhit lng vo v ra h thng sy: L(I2 I1) + [(G1 - W)Cv1 + WCa].tv1 = L(H2 Ho) + QBC + G2.Cv2.tV2t: Qv = G2Cv(tv2 tv1) : tn tht nhit do vt liu sy mang i.Mt khc: G2 = G1 W Cv1 = Cv2 = Cv Nhit lng tiu hao cho qu trnh sy thc:Q = L(H1 Ho) = L(H2 Ho) + QBC + Qv - WCatv1 Nhit lng tiu hao ring (cho 1kg m cn bc hi):q = l(H1 Ho) = l(H2 Ho) + qBC + qv Catv1trong :

; Tn tht nhit do vt liu sy: Qv = G2Cv(tv2 tv1) = 1918,367 0,7814 (65-26) = 58458,485 ; kJ/h

716,12 ; kJ/kg m Nhit do m trong vt liu a vo:WCatv1 = 81,633 . 4,18 . 26 = 8871,84 (kJ/h)Ca.tv1 = 4,18.26 = 108,68 (kJ/kg am) Tn tht nhit qua c cu bao che:QBC = (0,03 0,05). QhiQhi: nhit hu ch, l nhit cn thit lm bay hi m trong vt liu:Qhi = W.[rtv1 + Ca(t2 - tv1)]Vi: rtv1 : n nhit ha hi ca nc trong vt liu sy nhit vo, 2493 kJ/kg Ca : nhit dung ring ca m.Vi m l hi nc th Ca = Cpa = 1,842 kJ/kgoK

Qhi = 81.633.[2493 + 1.842.(6526)] = 210126,4 (kJ/h)

QBC = 0,03 Qhi = 0,03 . 210126,4 = 6303,79; kJ/h 77,22 ; kJ/kg mt = Catv1 qBC qv : nhit lng ring cn b sung cho qu trnh sy thc, l i lng c trng cho s sai khc gia qu trnh sy thc t v sy l thuyt. Vi qu trnh sy l thuyt: = 0Nhit lng tiu hao cho qu trnh sy l thuyt:Q = L (H2 Ho) = 1597,242 . (250,292470,321) = 287457,834; kJ/hq = l(H2 Ho) = 19,566. (250,292470,321) = 3521,36; kJ/kg m Vi qu trnh sy thc t: 0 = Catv1 qBC qv = 108,68 77,22 716,12 = - 684,66, kJ/kg m 0 Catv1 < qBC + qv

H2 < H1 Trng thi tc nhn sau qu trnh sy nm di ng H1 (ng sy thc t nm di ng sy l thuyt)T ta xc nh li cc tnh cht ca tc nhn sy khi ra khi thng sy

Tuy nhin v l cha bit nn ta xc nh cha m x2 trc thng qua t2 bit:

, kg/kg kk

H2 = = (1 + 1,97 . 0,058).70 + 2493 . 0,058 = 222,585; kJ/kg kk

, bar

, (m3/kgkk)Bng 3.2 - Trng thi ca tc nhn sy trong qu trnh sy thci lngTrng thi khng kh ban u (A)Trng thi khng kh vo thit b sy (B)Trng thi khng kh i ra khi thit b sy (C)

t (oC)2620070

(n v)0,80,00180,2815

x (kg/kgkk)0,01740,01740,058

H (kJ/kgkk)70,321250,2924250,2924

pb (bar)0,033515,71300,3073

v (m3/kgkk)0,90241,42891,104

Lng tc nhn kh cn thit

; kg/h Lng tc nhn tiu hao ring

; kg/kg m Lng nhit cn cung cp cho qu trnh sy thcQ= L(H2 Ho) + QBC + Qv - WCatv1 = 2011,8(222,585 70,321) + 6303,79 + 58458,485 8871,84 = 245297,887 (kJ/h)Lng nhit cung cp ring

, kJ/kg m Hiu sut sy:

= 85,66%

2. TNH THI GIAN SY Nhit trung bnh ca tc nhn sy trong thit b sy

m trung bnh ca tc nhn sy trong thit b sy:

Phn p sut bo ha ca hi nc trong tc nhn sy

, bar Khi lng ring ca tc nhn:

; kg/m3

Tnh thi gian sy:

, hVi: A l cng bay hi, A = 7,2 kg/m3h (Bng VII.3/122 [4]) ; h

3. TNH TON THIT B CHNH3.1. Tnh kch thc thng quay Th tch thng sy:

, m3 Chn ng knh thng, theo tiu chun DT = 1,6 m Chiu di thng:

Chon LT = 6 m thoa ieu kien Khi o, the tch cua thung say:

(m3)3.2. Thi gian luThi gian ma vat lieu lu tru trong thung (thi gian vat lieu i het chieu dai thung):

h = 66,6 pht

thoa ieu kien 1 3.3. Kim tra tc quay ca thng

, vng/phtrong :.k1 : h s lu n c tnh chuyn ng ca vt liu.Trng hp sy xui chiu: k1 = 0,2 0,7 Chn k1 = 0,7m : h s lu n dng cnh trong thng. i vi cnh nng, m = 1

(vg/ph) Chn s vng quay l 1 vng/pht3.4. Kim tra vn tc tc nhn syBng 3.3 - Lu lng v khi lng ring khng kh sy ca qu trnh sy thcai lngKy hieu n vTrang thai khong kh ban au A (trang thai 1)Trang thai khong kh vao thiet b sayB (trang thai 2)Trang thai khong kh ra khoi thiet b say - C (trang thai 3)

Nhiet ot (oC)2620070

o am (n v)0,80,00180,2815

Khoi lng rieng(kg/m3)1,1680,73860,996

Lng tc nhn sy trung bnh trong thng sy:

2325,33 ; m3/h = 0,7078; m3/s Tit din chy ca tc nhn:

; m2 Vn tc tc nhn sy

(m/s)3.5. Tnh b dy cch nhit ca thng3.5.1. H s cp nhit t dng tc nhn sy n thnh trong ca thng 1Bng 3.4 - Cc thng s ca tc nhn sy trong thng sySTTThong soK hieun vNguon Cong thcGia tr

1Van toc vkm/s(III.1)0,4295

2Nhiet o trung bnhtkoC(III.1)135

3He so dan nhietkW/m.oKBang I.137/149, [4]0,02607

4o nhtkNs/m2Bang I.114/118, [4]1,96.10-5

5Khoi lng riengkkg/m3(III.1)0,8652

6o nht ongkm2/s

2,265.10-5

Ch chy ca tc nhn sy trong thit b:Chun s Reynolds

Re 104 => dng tc nhn chy ri trong thng sy. Qu trnh truyn nhit trong thng xem nh l qu trnh truyn nhit trong ng c dng chy ri, l qu trnh c truyn nhit do s trn ln ca cc lp lu cht trong v ngoi xa trc ca dng chy.

Vy qu trnh truyn nhit gia tc nhn sy v thnh trong thit b l truyn nhit do i lu cng bc, dng chy trong ng c Chun s Nusselt:Nu = 0,018.l.Re0,8 (CT V.42/16, [5]

Trong : Vi: Re = 30337 l = 1,179(Bng V.2/15, [5])

Nu = 0,018.1,179.303370,8 = 81,73H s cp nhit 1

3.5.2. H s cp nhit t thnh ngoi ca thng sy n mi trng xung quanh 2:Qu trnh truyn nhit t thnh ngoi ca thit b sy n mi trng xung quanh l qu trnh truyn nhit do i lu t nhin v do bc x nhit. H s cp nhit do i lu t nhin 2Do thung sy t nm ngang vi gc nghing = 2o nn vic xc nh cc h s cp nhit do i lu t nhin xem nh l xc nh cc h s cp nhit ca ng nm ngang khi khng kh c th tch ln chuyn ng t do. Trong trng hp ny, cc hng s vt l khi tnh chun s Nu, Gr ly theo nhit trung bnh ca lu cht xa ng, tc l ly theo nhit trung bnh ca khng kh mi trng.Bng 3.5 - Cc thng s ca khng kh bn ngoi thng sySTTThong soK hieun vNguon Cong thcGia tr

1Ap suat hi bao hoapbbar(III.1)0,0335

2Nhiet o tooC(III.1)26

3He so dan nhietoW/m.oKBang I.137/149, [4]0,02607

4o nhtoNs/m2Bang I.114/118, [4]1,84.10-5

5Khoi lng riengokg/m3(III.1)1,168

6o nht ongom2/s

1,5784.10-5

Chn nhit thnh ngoi ca thng (pha tip xc vi khng kh): tw4 = 35oC -> l nhit thch hp nhit t tc nhn sy sau khi truyn qua lp vch thng v lp cch nhit n pha thnh ngoi ca thng th khng cn qu nng, an ton cho ngi lm vic.Do h s dn nhit ca thp ln nn xem nh nhit khng i khi truyn qua b dy thn thng v lp bo v. S truyn nhit:

1: b dy thn thng2: b dy lp cch nhit3: b dy lp bo v

Hnh 3.1: S truyn nhit qua vch thngChn cc b dy ca thngBng 3.6 - Cc b dy ca thng v vt liuSTTai lngKy hieuGia tr chon (m)Vat lieuHe so dan nhiet (W/mK)

1Be day thung10,008OX18H10T16,3

2Be day lp cach nhiet20,005Bong thuy tinh0,05

3Be day lp bao ve30,002CT350

ng knh ngoi ca thng sy: Dng = DT + 2.( 1 + 2 + 3) = 1,6 + 2.(0,008 + 0,005 + 0,002) = 1,63, mChun s Grashof:

Chun s Nusselt:Nu = 0,47. Gr0,25 = 125,93H s cp nhit 2:

(W/m2K) H s cp nhit do bc x nhit 2:

,W/m2K(CT V.135/41, [5])

Trong :Qbx: nhit trao i do bc x, WF: b mt bc x, m2T1: nhit ca vt th nng, K, T1 = tw4T2: nhit ca vt th ngui, l nhit khng kh bao quanh thng, k, T2 = to1-2: en ca hi vi bc x gia kh v b mt vt th, do b mt vt th ca kh ln hn b mt vt th nn en ca h xem nh bng en ca vt th: 1-2 1 = 0,8 1 chn 1-2 = 0.8

(W/m2.K)

H s cp nhit chung 2:

, (W/m2.K)(CT V.134/41, [5])

3.5.3. H s truyn nhit KH s truyn nhit K i vi tng hnh ng c chiu dy khng dy lm so vi ng knh, khi b qua nhit tr ca lp cu:

, W/m2.K

3.5.4. Tnh b mt truyn nhit Fng knh trung bnh ca thng sy:

, mB mt truyn nhit: gm din tch xung quanh thng v din tch hai mt u ca thng:

, m2

3.5.5. Tnh hiu s nhit trung bnh gia tc nhn sy v khng kh bn ngoi ttbGi: t1, t1c: nhit u v cui ca tc nhn sy khi i qua thng syt1 = t1 = 200oCtc1 = t2 = 70oCt2, t2c: nhit mi trng xung quanh, t2 = t2c = to = 26oCHiu s nhit ca 2 dng lu cht u vo v u ra ca thng sy:t = t1 t2 = 200 26 = 174 oCtc = t1c t2c = 70 26 = 44 oCHiu s nhit trung bnh gia tc nhn sy v khng kh bn ngoi:

, oC3.5.6. Tnh lng nhit mt mt ra xung quanhXem nhit truyn t bn trong thng sy qua lp cch nhit, n mi trng bn ngoi l n nh. Lng nhit chnh l lng nhit mt mt ra mi trng xung quanh khi bc hi 1kg m, qxq. i vi my sy thng quay th lng nhit mt mt ny cng l nhit tn tht qua c cu bao che qBC.Theo phng trnh truyn nhit:

, J/kg am

So sanh vi lng nhiet ton that qua c cau bao che gia thiet ban au

B dy lp cch nhit chn tha3.6. Kim tra b dy thngVt liu sy l vt liu c n mn ha hc cao v lm vic nhit cao nn ta chn vt liu OX18H10T.Bng 3.7 - Cc tnh cht vt liu ch to thngSTTThong soK hieun vNguon Cong thcGia tr

1ng suat tieu chuan [*]N/mm2Hnh 1-2/22, [6]128

2Gii han an toann vtrang 26 [6]0,95

3He so ben moi hanhn vBang 1.7/24, [6]0,95

4ng suat cho phep[]N/mm2[] = h.[*](CT 1.9/23, [6])121,6

p sut lm vic ca h thng: thng sy lm vic p sut thng, chiu dy thnh thit b tnh theo thit b lm vic vi p sut trong nhng ly p b hn 0.1106 N/m2. p sut lm vic ca h thng, ly p = 0,1.106 N/m2 = 0,1 N/mm2Ta c:

Do b dy ti thiu ca thn thng:

H s b sung kch thc: C = Ca + Cb + Cc + CoBng 3.8 - Cc h s b sung kch thc cho b dy thngSTTHe so bo sung kch thcK hieuGia tr (mm)Ghi chu

1He so bo sung do an mon hoa hocCa0oi vi vat lieu ben trong moi trng co o an mon hoa hoc khong ln hn 0.05 mm/nam.

2He so bo sung do bao mon c hocCb1Do nguyen lieu la cac hat ran chuyen ong, va ap trong thiet b. Gia tr Cb chon theo thc nghiem.

3He so bo sung do sai lech khi che taoCc0,8Phu thuoc vao chieu day cua tam thep lam thung. Vi thung bang thep CT3, day 8mm th Cc = 0.8 mm (Bang XIII.9, [1])

4He so quy tron kch thcCo 5,75Chon.

C = Ca + Cb + Cc + Co = 0 + 1 + 0,8 + 5,75 = 7,55 , mmB dy thc ca thn thng:S = S + C = 6,9.10-4 + 7,55.10-3 = 8,2.10-3, m Chn b dy 8mm l hp lKim tra:

Tha iu kin p sut ln nht cho php trong thn thit b:

, N/mm2 Vy thng sy c b dy l 8mm tha iu kin lm vic p [p]Bng 3.9 - Khi lng thng syThong soVat lieuKhoi lng rieng (kg/m3)ng knh trong (m)ng knh ngoai (m)Khoi lng (kg)

Than thungOX18H10T.79001,61,6161914,63

Lp cach nhietBong thuy tinh2001,6161,62630,54

Lp bao veCT378501,6261,3481,54

Khi lng thng : Mthng = 2426,71 , kg3.7. Tnh tr lc qua thng syTrong h thng sy thng quay, tc nhn sy khng nhng i qua lp ht nm trn cnh v trn mt thng sy m cn i qua dng ht ri t nh thng v t cc cnh trn xung. Do , tr lc ca tc nhn sy trong thng sy c nhng c th ring v c tnh theo cc cng thc kinh nghim.Chun s Reynolds:

Khi lng ring dn xut ca khi ht chuyn ng trong thng sy:

Tr lc ca dng tc nhn i qua lp vt liu trong thng sy:

,mmH2O (CT 10.19/213 - [1])Trong : a: h s thy ng

(CT 10.20/213[1]) C: h s c trng cho cht ca lp ht

(CT 10.21/213, [1])

vi : (CT 10.22/213, [1])

3.8. Tnh chn cnh o trnMt s thng s c bn ca cnh nng c chn trn.Chiu cao ri trung bnh ca ht vt liu:

=> h = 0,576.DT = 0,576.1600 = 921,6, mmDin tch b mt cha vt liu ca cnh:

=> Fc = 0,122 . = 0,122 . 16002 = 312320, mm2

Hnh 3.2: Kch thc cnh o trnTheo cc k hiu kch thc trn hnh ca cnh o trn, ta c:

Chn cc thng s cho cnh:. a = 200 mm. b = 280 mm 650,67 mm => Chn c = 650 mm. d = 4mmVat lieu che tao canh la thep khong r X18H10T, = 7900 kg/m3So canh tren mot mat cat: 12 canh.So canh can lap: canhKhoi lng 1 canh ao tron:m = . Vc = . Fc . d = 9,87; kgKhoi lng cua canh trong thung:M = z . m = 1085,6; kg Chieu cao lp vat lieu trong thung:

Hnh 3.3: Din tch phn vt liu trong thngFc : tiet dien cha ay

Fc = .Ft = Do:

Chieu cao cha ay vat lieu trong thung:h = R Rcos =0,4 (m).4. THIT K B PHN TRUYN NG4.1. Chn ng cCng sut cn quay thng: N = 0,0013.DT2.LT..n. kW (CT VII.54/123, [5])vi:.DT : ng knh trong cua thung, DT = 1,6 m..LT : chieu dai thung, LT = 6 m..: he so phu thuoc vao dang canh.Vi canh nang, he so cha ay = 0,18 th = 0,059 (Bang VII.5/123, [5]). n : toc o quay cua thung, n = 1 vg/ph.. : khoi lng rieng xop cua vat lieu, = 1020 kg/m3 N = 0,0013.DT2.LT..n. = 1,2 kWChon ong c loai A02418, co cac thong so sau:(Bang 2P/323[7]) Cong suat ong c: Nc = 2,2kW. Toc o quay:nc = 720 vong/phut. Hieu suat: = 0,81.Cong suat lam viec cua ong c:

Vay Nlv > N, do o thoa ieu kien can e quay thung.4.2. Chon t so truyen ongT so truyen ong chung cua he thong:

Do t so truyen cua ong c ln, nen can phai s dung bo giam toc cho ong c. ay, ta s dung hop giam toc truc vt banh rang. Cau tao cua hop giam toc nh hnh ve:Chon cac t so truyen:i12 = 4i23 = 6

T so truyen t ong c sang truc vt:

So vong quay cua cac truc: i.nk

Cong suat can e quay thung: N= 1,484 kWHnh 3.4: C cu truyn ng

Cong suat cac truc: .Nk

Trong o, theo bang 21/27[7], chon hieu suat cac bo truyen nh sau: Bo truyen banh rang tru h: h = 0,93. Bo truyen banh rang tru kn: kn = 0,96. Bo truyen truc vt: Bng 3.10 - Ket qua tnh ton t s truyn ngTruc ong cIIIIII

i3064

n (vong/phut)7202441

N (kW)1,4841,3461,2921,2

4.3. Tnh bo truyen banh rangBo truyen nay co chc nang truyen ong t tang dan ong en banh rang ln gan vao thung. ay la s truyen ong gia 2 truc song song, do o ta chon bo truyen banh rang tru rang thang, an khp ngoai, truyen ong h.0. Chon vat lieu che tao banh rang:Chon nhom banh rang co o ran HB 350, c cat got chnh xac sau nhiet luyen (do o ran tng oi thap), khong oi hoi phai qua cac nguyen cong tu sa at tien nh mai, mai nghien Banh rang co kha nang chay mon tot. e tranh dnh be mat lam viec cua rang, lay o ran cua banh rang nho ln hn banh rang ln 3050HB, chon mac thep banh nho khac banh ln. Banh rang ln: (Bang 38/40[7]) Vat lieu:thep C35 thng hoa. o ran: HB = 160 Gii han ben keo:b = 480 N/mm2 Gii han chay:ch = 240 N/mm2 Banh rang nho: Vat lieu:thep C45 thng hoa. o ran: HB = 190 Gii han ben keo:b = 580 N/mm2 Gii han chay:ch = 290 N/mm2 Xac nh ng suat uon cho phep:oi vi rang lam viec mt mat:

, N/mm2 (CT 35/42[8])Trong o: 1 (N/mm2): gii han moi uon. Thep C45: -1 = 0,45.580 = 261, N/mm2 Thep C35: -1 = 0,45.480 = 216, N/mm2 n: he so an toan. oi vi banh rang bang thep ren thng hoa, chon n = 1,5. k: he so tap trung ng suat chan rang. oi vi banh rang lam bang thep thng hoa, chon k = 1,8.ng suat uon cho phep cua: Banh rang nho:, N/mm2

Banh rang ln:, N/mm2

Chon he so tai trongK = 1,31,5.Do ta s dung bo truyen che tao bang vat lieu co kha nang chay mon, van toc thap, nen chon he so tai trong K = 1,3. Chon chieu dai tng oi cua rangoi vi bo truyen banh rang tru rang thang, truc va o tng oi cng(HB 350), theo bang 317/51, [7]:

Trong o:b (mm): chieu rong banh rang.m (mm): moun cua banh rang.Chon m = 20. Chon so rang va he so dang rang:Chon so rang cua banh rang nho (banh rang dan ong) Z1 = 35 (rang).Theo bang 318/52, [7], chon he so dang rang y1 = 0,4125. Tnh moun cua banh rang:

Chon moun cua banh rang tru theo tieu chuan (Bang 31/34,[7]): m = 12 mm. Xac nh khoang cach truc A, so rang va chieu rong banh rang:Khoang cach truc c xac nh theo cong thc sau:m = (0,01 0,02).A

(CT 322/49, [7])Chon khoang cach truc gia 2 banh rang A = 875 mm.

So rang banh dan (nho): 35, rang (CT 324/49, [7])

So rang banh b dan (ln): Z2 = I . Z1 = 4.35 = 140, rang Chieu rong banh rang dan: b = m . m = 20 . 12 = 240, mmChieu rong banh rang b dan: b = 240 12 = 228 , mm Kiem nghiem sc ben uon rang

(CT 333/49,[7])He so dang rang y c xac nh theo bang 3-18/52, [7]: Banh rang nho:y = 0,4125 Banh rang ln:y = 0,517ng suat uon tai chan rang banh nho:

ng suat uon tai chan rang banh ln:

Vay banh rang thoa ieu kien ben uon cua rang.Bng 3.11 - Cc thng s hnh hc ch yu ca b truynGoc an khp = 20.STTThong soK hieu n vCong thc tnhBanh rang dan (nho)Banh rang b dan (ln)

1Mounm (mm)12

2So rangZ (rang)35140

3ng knh vong landl (mm)

4201680

4Khoang cach trucA (mm)

875

5Chieu rong banh rangb (mm)240228

6ng knh vong nh rangDe (mm)

4441704

7ng knh vong chan rangDi (mm)

3901650

8Chieu cao au ranghd (mm)

12

9Chieu cao rangH

27

Tnh lc tac dung len truc: (khong xet lc ma sat)Moment xoan Mx:

= 3084943, N/mm3(CT 353/55,[7])

Lc vong P: (CT 349/54,[7])Lc hng tam Pr : Pr = P.tan = 14690,2.tan20o = 5343,85, NLc doc truc oi vi bo truyen banh rang tru rang thang: Pa = 0. Khoi lng banh rang:Banh rang lam bang thep C35, = 7850 kg/m3.

= 232,53 kg5. TNH VANH AIChon s bo cac thong so cua vanh ai nh sau: Be rong cua vanh ai: B = 100 mm. Be day vanh ai la hieu gia ban knh ngoai va ban knh trong cua vanh ai. oi vi thung tai trong nang, be day vanh ai xac nh nh sau:

Ta chon h = 40 mm. Vat lieu lam vanh ai: thep CT3, = 7850 kg/m3. Gan e lap vanh ai vao than thung: cao 56mm, day 40mm Khoang cach gia gan va than thung e lap chan e: 50mm ng knh mat ngoai chan e (ng knh trong cua gan):De = DT + 2.60 = 1630 + 2.60 = 1750 (mm) ng knh ngoai vanh ai:Dai = 1630 + 2.(60 + 50 + 40) = 1930 (mm) Khoi lng 2 vanh ai:Mai = 2..(Vai + Vgan)= 2.7850..[(1,52+0,1).0,1.0,04 + (1,320+0,04).0,04.0,05]= 576,8 (kg)6. TNH CON LAN Tai trong cua thung:

= (2426,7 + 1085,6 + 609,72 + 232,53 + 2000)9,81= 62338,4 N

Chon goc gia 2 con lan la 2 = 60 = 30.Phan lc cua moi con lan len vanh ai:

(CT 527/245,[6])Hnh 3.5: Con ln

Phan lc T gom 2 thanh phan: Lc ay con lan trt theo phng ngang:S = T.sin = 35985,4.sin30o = 17984,5 N Lc ep goi con lan len be:N = T.cos = 35985,4 . cos30o = 31169,2 NBe rong con lan :, cm

(CT 534/245,[6])ng knh con lan bang thep:

(CT 536/245,[6])Mat khac:0,25.Dai dc 0,33.Dai 0,25.1896 dc 0,33.1896 482,5 dc 636,9 (CT 537/245,[6])Vay chon ng knh con lan dC = 500 mm.7. TNH CON LAN CHANLc doc thung U c xac nh nh sau:U = Q.sin = 62338,4 . sin2o = 2174,5 NLc U co khuynh hng keo thung tut xuong, do o ta at con lan chan sat vanh ai e gia thung v tr on nh. Tren thung quay, ta lap hai con lan chan nam ve hai pha cua vanh ai at gan banh rang vong.oi vi thung co kch thc ln va nang, ta lam con lan chan mat non.Khi lap at, lap sao cho truc con lan vuong goc vi mat at.Goc nghieng cua con lan:

Trong o d: ng knh con lan chan. = 2: goc nghieng cua thung quay. sin2o = d = sin2o. 1896 = 66,14 mmChon d = 70 mm.Lc ln nhat tac dung len con lan chan:

Trong o, f la he so ma sat gia vanh ai va con lan chan, chon f = 0,1. Fmax = 62338,4 (0.1 + sin2o) = 239,3 N

8. TNH TON THIT B PH8.1. CaloriferCalorifer l thit b truyn nhit dng gia nhit gin tip cho khng kh sy. V nhit sy ca ta kh cao: 200oC nn ta s dng calorifer kh - kh dng ng chm. Trong ng l khi l c t bng du FO, ngoi ng l khng kh chuyn ng.Bng 3.12 - Cc thng s ca cc tc nhn qua caloriferTc nhn sykhng khNhit vo t2 = to26oC

Nhit ra t2c = t1200o

Du FOKhi lp sut p1at

Nhit khi250oC

Tnh cc h s truyn nhit Tnh h s truyn nhit khng kh ngoi ng 1Bng 3.13 - Thng s tc nhn khng kh chuyn ng ngoi ngSTTThong soK hieun vNguon Cong thcGia tr

1Nhiet o trung bnhtkoC

113

2o am trung bnhkn v

0,4009

3He so dan nhietkW/m.oKBang 30, [3]0,0315

4o nhtkNs/m2Bang I.114, [1]2,244.10-5

5Ap suat hi bao hoapbbar(II)1,5627

6Khoi lng riengkkg/m3CT 1.11, [8]0,515

7o nht ongkm2/s

4,3574.10-5

Lu lng khng kh cn c gia nhit l 0.7078 m3/s, chn ng knh ca ng dn kh l 1mVn tc dng kh trong ng ng:

Vn tc dng kh tnh ca vo thit b truyn nhit ng knh 0.2m

, m/sChun s Reynolds:

S cp nhit khi ng xp thng hang, ta c:Nu = 0,21..Re0,65 y ta ly dng kh i vung gc vi ng nn = 1Nu = 0,21.5173350,65 = 1086,85H s cp nhit:

, W/m2.K H s cp nhit ph trong ng 2S cp nhit pha trong ng l do khi lTa tnh ging nh s cp nhit chuyn ng trong ng thngCc thng s ta chn:ng knh: D = 0,05m, chiu di: 2mB dy ng: = 0,001m, thp CT20 c h s dn nhit = 57 W/mKH s trao i nhit cng bc chuyn ng trong ng c cng thc thc nghim: (CT PVI-3/277,[8])Trong :B: h s c xc nh ti t = 250oC v B = 3,085: trng lng ring ca kh (kg/m3) v = 2,166kg/m3W: vn tc ca kh trong ng, chn W = 10m/sD: ng knh tng ng , W/m2KH s truyn nhit K

, W/m2K

Hieu so nhiet o cua 2 dong lu chat au vao va ra cua calorifer:t = T t2 = 250 26 = 224 oCtc = T t2c = 250 200 = 50 oC Hieu so nhiet o trung bnh gia tac nhan say va hi nc cap nhiet:Chn hiu sut calorifer l = 85%Nhit lng cn cp lQ = L(I1 - Io) = 425960,7 kJ/h = 118322,42 J/sDin tch b mt trong ng

, m2

Tng s ng: ng8.2. CycloneKhi tc nhn sy i trong thng sy sau khi thot ra ngoi thng mang theo bi, v th cn phi thu hi lm sch khng kh.Trong h thng sy thng quay thng dng cyclon n H-15 vi gc nghing ca ca vo = 15o, loi ny m bo sch ln nht vi h s sc cn thy lc nh nht.Lu lng cyclone l lu lng ca tc nhn sy:Vc = V2 = 0,6172 m3/s = 2222 m3/hChn ng knh cyclone D = 500mmBng 3.14 - Kch thc ca cyclone n loi H-15 ( Bng III.4/524, [4])STTTn giK hiuCng thcGi trn v

1ng knhD500mm

2Chiu cao ca voa0,66D330

3Chiu cao ng tm c mt bchh11,74D870

4Chiu cao phn hnh trh22,26D1130

5Chiu cao phn hnh nnh320D10000

6Chiu cao phn bn ngoi ng tmh40,3D150

7Chiu cao chungH4,56D2280

8ng knh ngoi ca ng rad10,6D300

9ng knh trong ca ca tho bid20,3-0,4D150

10Chiu rng ca ca vob1/b0,26D/0,2D130/100

11Chiu di ca ng ca vol0,6D300

12Khong cch t tn cng cyclon n mt bchh50,24-0,32D150

13Gc nghing gia np v ng vo15

14H s tr lc ca cyclone105n v

Tc quy c ca kh

, m (CT III.47/522,[4])

m/s Tr lc qua cyclone:

(CT III.50/522,[4])

Hnh 3.6: Cyclone n8.3. Tnh ton kh ng v chn qut gi8.3.1. Tnh tr lc h thng ng ngDo h thng sy di nn ta dng 2 qut t u v cui h thngQut t u h thng c tc dng a kh vo thit b trao i nhit v a kh vo thit b sy, qua 2 on ng cong 90oQut t dau h thng c tc dng a kh ra khi h thng v a kh vo thit b lc cyclone, qua 1 on ng cong 90oBng 3.15 - Lu lng kh ai lngKy hieu n vTrang thai khong kh ban au A (trang thai 1)Trang thai khong kh vao thiet b say B (trang thai 2)Trang thai khong kh ra khoi thiet b say - C (trang thai 3)

Nhiet ot (oC)2620070

o amV (m3/h)1815,52874,632221,8

V (m3/s)0,50430,79850,6172

Khoi lng rieng(kg/m3)1,1680,73860,996

o nhtk (Ns/m2)1,84.10-52,06.10-52,576.10-5

Ta chn qut c p sut trung bnh s hiu 9-57, No5 c kch thc:Mt bch ca ra: hnh vung B = 350 mmMt bch ca vo: hnh trn D = 209 mm

Bng 3.16 - Thit k h thngSTTBt u on ngon ngKt thc on ng

im bt uKch thc (mm)Chiu di l (m)Kch thc (mm)Lu lng kh V (m3/s)Vn tc kh v (m/s)im kt thcKch thc (mm)

1Ca ra qut y35024000,50434,0152Li vo thit b truyn nhit250

2Ca ra thit b truyn nhit25024000,79856,3576Ca vo thng nhp liu400

3Ca ra thng tho liu429x1692429x1690,61728,5125Ca vo cyclon429x169

4Ca ra ca cyclone40024000,61724,9137Ca vo qut ht509

Hnh 3.7: S ng ng ca h thng sy n Qu trnh & Thit b - Sy thng quay CBHD: Thy Mai Thanh Phong

Nguyn Th Thy Linh 1

SV: Nguyn Th Thy Linh 11

1 - Qut y2 - Calorifer3 - Thng nhp liu v dn kh vo4 - Thng sy5 - Thng tho liu v dn kh ra6 - Cyclon7 - Qut ht

Tr lc ma st trn ng ngChun s Reynolds

, trong o: v, k, k : van toc (m/s), khoi lng rieng (kg/m3), o nht (Ns/m2) cua khong kh say tai cac v tr tng ng. Dt : ng knh tng ng cua ng ong (m) Ong tron : Dt = Dong Ong hnh ch nhat : . a, b : chieu dai 2 canh cua tiet dien ong, (m). S : dien tch tiet dien ong, (m2).. : chu vi tiet dien ong, (m). Vi khong kh chay xoay roi, Re 4000, xem dong chay khu vc nhan thuy lc he so tr lc ma sat , theo Bang II.12/379, [4]. Ap suat can thiet e khac phuc tr lc ma sat trong ong dan:

(CT II.55/377, [4])

Bng 3.17 - Kt qu tnh tr lc ma st trn ng ngSTTon ngL (m)Dt (m)ReP1 (N/m2)P1 (mmH2O)

1T sau qut y n trc thit b truyn nhit20,4101954,260,0180,8470,086

2T sau thit b truyn nhit n trc thit b sy20,491175,450,0181,3430,137

3T sau thng sy n cyclon20,242579798,150,0195,6550,576

4T sau cyclone n qut ht20,475986,130,0191,1420,116

Tnh tr lc cc b:p sut cn thit khc phc tr lc cc b trong ng dn:

(CT II.56/377, [4])

vi: . : He so tr lc cuc bo.0. H s tr lc t mH s tn tht ct p cc b ca dng chy qua ng phn k:

(CT P8.5, [9])vi:.A1, A2 : dien tch tiet dien ong nho va ong m rong, m2..k : he so. Vi goc m = 6o th k = 0,1 (Bang b2, [9]). Ap suat Pcb tnh theo v2.Bng 3.18 - p sut cn thit khc phc tr lc cc b do t mSTTV tr tr lcng nhng m rngP1 (N/m2)P1 (mmH2O)

t1 (m)A1 (m2)t2 (m)A2 (m2)

1T ca ra qut y n ng ng0,350,09620,40,12560,005490,06600,0067

2T ca ra thit b truyn nhit n ng ng0,250,04910,40,12560,037130,44640,0455

3T ng n ca vo qut ht0,40,12560,5090,20340,014630,17580,0179

0. H s tr lc do t thuV tr co tr lc do ot thu la t ng ong vao caloriphe..A1 = 0,0491: dien tch tiet dien ong nho (loi vao caloriphe), m2..A2 = 0,1256: dien tch tiet dien ong ong m rong (ng ong), m2.He so ton that cot ap cuc bo cua dong chay qua ong hoi tu:

(CT P8.9, [9])vi:.k : he so. Vi goc hoi tu = 60o th k = 0,2 [4]. : he so co hep. (CT P8.7, [9])

Ta co: n = A1/A2 = 0,39 < 0,6 th:

Van toc kh tai loi vao caloriphe: v2 = 6,3576 m/s.Ap suat can thiet e khac phuc tr lc cuc bo do ot thu Pcb4 tnh theo v2:

0. H s tr lc ti on un cong 90o i vi ng tit din trn:Tren he thong co 2 lan uon cong 90o tren ong tron la sau caloriphe e en he thong say v sau thng tho liu n cyclone.He so ton that cot ap cuc bo cua dong chay tai cho uon cong, oi vi ong tiet dien tron:

(CT P8.10, [9])vi:.Ro : ban knh uonD : ng knh ong

Chon k = 0,29 (Bang b7, [9])

Ap suat can thiet e khac phuc tr lc cuc bo do 2 lan uon cong 90o tren ong tron Pcb5:

i vi ng tit din vung:V tr uon la trc xyclon, sau thung say.He so ton that cot ap cuc bo cua dong chay tai cho uon cong, oi vi ong tiet dien hnh ch nhat: = A.B.Cvi:.A = 1 (Bang II.16/393, No24, [4]).Chon R/Dt = 4 B = 0,11 (Bang II.16/393, No25, [4])

.Ta co: C = 1,59 (Bang II.16/393, No26, [4]) = A.B.C = 1.0,11.1,59 = 0,1749Ap suat can thiet e khac phuc tr lc cuc bo do uon cong 90o tren ong tiet dien ch nhat Pcb6:

0. Tr lc trn ng thngHe so tr lc tren ong thang trc tiep:Ta co : (Bang II.16, No23, [4])Ap suat can thiet e khac phuc tr lc cuc bo tren ong thang Pcb8:

Tr lc cho h thngTn tht ct p ng ti ca ra ca qut: Vn tc kh ti ca ra ca qut:

,m/s Tn tht ct p ng:

Tn tht ct p tnh ton:Ptt = Pt + PN/m2Tn tht ct p ton phn, iu kin lm vic (do s dng c tuyn thnh lp cho iu kin tiu chun):

,N/m2(CT II.238a/463, [4])vi:.t : nhiet o lam viec cua kh, oC.B : ap suat tai cho at quat, B = 760 mmHg.k : khoi lng rieng cua kh ieu kien lam viec, kg/m3.Bng 3.19 - Tn tht ct p m qut phi khc phcQut yQut ht

Tn tht ma stPmsCng thcP1+P2P3+P4

Gi tr (N/m2)2,1916,797

Tn tht cc bPcbCng thcP1+P2 +P4+P5+P6P3+P7

Gi tr (N/m2)9,54302,8518

Tn tht ct p tnhPtCng thcPms+Pcb+PtbtnPms+Pcb+Pht+Pcyclon

Gi tr (N/m2)21,38231378,195

Tn tht ct p ngP (N/m2)69,82322,6

Tn tht ct p tnh tonPtt (N/m2)91,211700,8

Tn tht ct p ton phnP (N/m2)87,3751670,2

8.3.2. Tnh cng sut v chn qut Nang suat cua quat V (m3/h): oi vi khong kh t ban th nang suat quat lay bang lu lng khong kh theo tnh toan ieu kien lam viec.Tr lc ma quat phai khac phuc P (N/m2): lay ton that cot ap toan phan ieu kien lam viec.Cong suat tren truc ong c ien, khi van chuyen khong kh nhiet o cao:

,kW(CT II.239b/464, [4])vi:.q : hieu suat quat, lay theo ac tuyen.tr : hieu suat truyen ong. Khi truyen ong bang banh ma sat tr = 0,9Cong suat ong c ien:Nc = k3.N,kW(CT II.240/464, [4])vi: .k3 : he so d tr. Bng 3.20 - Tnh cng sut v chn qutSTTai lngKy hieuQuat hutQuat ayGhi chu

1Nang suat trung bnhV (m3/s)0,61720,5043

2Khoi lng rieng trung bnh tac nhan (kg/m3)0,9961,168

3Ton that cot ap toan phanP (N/m2)1670,287,4

4Hieu suat quatq0,650,65Tra o th ac tuyen quat ly tam 9-57, No5 (Hnh II.58, [4])

5Cong suat tren truc ong c ienN (kW)8,618,94

6Cong suat ong c ienNc (kW)9,479,834Vi N > 5 kW th k3 = 1,1

Cac thong so cua quat va ong c: ta s dung 2 quat 9-57, No5 co cac thong so giong nhau.Bng 3.21 - Cc thng s ca qut v ng cThong soKy hieuGia trGhi chu

QuatKy hieu quat 9-57, No5Tra o th ac tuyen quat ly tam 9-57, No5 (Hnh II.58, [4])

Hieu suat0,65

Toc o vong cua banh guongv (m/s)4,19

(rad/s)150

ong cKy hieu ong c4A160S4Y3Bang P1.3, [4]

Cong suatNc (kW)15

Hieu suatc0,89

Toc o quayvc (vg/ph)1460

He so cong suatcos0,88

PHN 4: KT LUNSy l mt phng php n gin nhm loi b m ra khi vt liu, gip bo qun cc ngun nng sn, thc phm c lu hn.Sy mui vi thit b l thng quay c cng sut nh, t tn nng lng, cch vn hnh n gin, cho nng sut cao, m mui t tiu chun nht nh ng thi khng gy nhim mi trng, ph hp vi cc xng sn xut mui vi nhiu quy m khc nhau.Tnh ton thit b cn da vo nhiu cng thc thc nghim t a ra phng n thit k tt nht cho thit b. Tuy nhin trong qu trnh tnh ton v thit k cng khng trnh khi nhng sai st do sai s v cn nhiu bt tin nh nhit t t du khng n nh, thit b to, cng knh, chi ph ch to cao.PHN 5: TI LIU THAM KHO[1] Trn Vn Ph, Tnh ton v thit k h thng sy, NXB Gio dc, 2002.[2] Nguyn Vn La, K thut sy vt liu, NXB HQG TPHCM, 2001[3] Nguyn Vn May, K thut sy nng sn thc phm, NXB KHKT, 2002.[4] Trn Xoa v cc tc gi, S tay qu trnh v thit b cng ngh ha cht - tp 1, NXB KHKT, 1999.[5] Trn Xoa v cc tc gi, S tay qu trnh v thit b cng ngh ha cht - tp 2, NXB KHKT, 1999.[6] H L Vin, Thit k - tnh ton cc thit b ha cht - Tp 1, NXB KHKT, 1978.[7] H L Vin, Thit k - tnh ton cc thit b ha cht - Tp 2, NXB KHKT, 1978.[8] Nguyn Trng Hip, Nguyn Vn Lm, Thit k chi tit my, NXB Gio dc, 2000.[9] Hong Vn Chc, K thut sy, NXB KHKT, 1999