Ccat Acid Acetic-Nuoc(Mam Xuyen Lo)

8/3/2019 Ccat Acid Acetic-Nuoc(Mam Xuyen Lo)

1/77

AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO

MUC LUC

trangLI M AU

CHNG I : TONG QUAN.......................................I . LY THUYET VE CHNG CAT1 . Phng phap chng cat2 .Thiet b chng cat:

II . GII THIEU S BO NGUYEN LIEU1 . Acid axetic2 . Nc3 . Hon hp Acid axetic Nc

III . CONG NGHE CHNG CAT HE ACID AXETICNCCHNG II : CAN BANG VAT CHATI . CAC THONG SO BAN AUII . XAC NH SUAT LNG SAN PHAM NH VASAN PHAM AY

III . XAC NH T SO HOAN LU THCH HP1 .T so hoan lu toi thieu2 .T so hoan lu thch hp

IV . PHNG TRNH NG LAM VIEC SO MAMLY THUYET1 . Phng trnh ng nong o lam viec cua

oan cat2 . Phng trnh ng nong o lam viec cua

oan chng3 . So mam ly thuyet

V . XAC NH SO MAM THC TE

CHNG III :TNH TOAN THIET KE THAPCHNG CATI . NG KNH THAP1 . ng knh oan cat2 . ng knh oan chng

II . MAM LO TR LC CUA MAM1 . Cau tao mam lo2 . o giam ap cua pha kh qua mot mam3 . Kiem tra ngap lut khi thap hoat ongO(

III .TNH TOAN C KH CUA THAP

1

1

1

2

4

56

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

2223

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

2


2/77


1 . Be day than thap :2 . ay va nap thiet b :3 . Bch ghep than, ay va nap :4 . ng knh cac ong dan Bch ghep cac

ong dan :5 . Tai treo va chan :

CHNG IV : TNH TOAN THIET B TRUYENNHIET- THIET B PHU

I . CAC THIET B TRUYEN NHIET1 . Thiet b ngng tu san pham nh2 . Thiet b lam nguoi san pham nh3 . Noi un gia nhiet san pham ay

4 . Thiet b trao oi nhiet gia nhap lieu vasan pham ay5 . Thiet gia nhiet nhap lieu

II.TNH BAO ON CUA THIET BIII .TNH TOAN BM NHAP LIEU1 . Tnh chieu cao bon cao v2 . Chon bm

CHNG V : GIA THANH THIET BI .TNH S BO GIA THANH CUA THIET B

II . KET LUANTAI LIEU THAM KHAO

2

5

40

41

42

43

4445

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

616263

64

65

66

67

68

6970

71

72

6


3/77


LI M AU

Mot trong nhng nganh co s ong gop to ln ennganh cong nghiep nc ta noi rieng va the gii noi

chung, o la nganh cong nghiep hoa hoc. ac biet langanh hoa chat c ban.Hien nay, trong nhieu nganh san suat hoa hoc cung nh

s dung san pham hoa hoc, nhu cau s dung nguyenlieu hoac san pham co o tinh khiet cao phai phu hpvi quy trnh san suat hoac nhu cau s dung.

Ngay nay, cac phng phap c s dung e nang caoo tinh khiet: trch ly, chng cat, co ac, hap thu Tuytheo ac tnh yeu cau cua san pham ma ta co s lachon phng phap thch hp. oi vi he acid axetic- Nc

la 2 cau t tan lan hoan toan, ta phai dung phngphap chng cat e nang cao o tinh khiet cho acid axetic.o an mon hoc Qua trnh va Thiet b la mot mon

hoc mang tnh tong hp trong qua trnh hoc tap cua cacky s hoa- th c pham tng lai. Mon hoc giup sinh viengiai quyet nhiem vu tnh toan cu the ve: yeu cau congnghe, ket cau, gia thanh cua mot thiet b trong sanxuat hoa chat - thc pham. ay la bc au tien esinh vien van dung nhng kien thc a hoc cua nhieumon hoc vao giai quyet nhng van e ky thuat thc

te mot cach tong hp.Nhiem vu cua AMH la thiet ke thap chng cat he acidaxetic - Nc hoat ong lien tuc vi nang suat nhaplieu : 5m3/h co nong o 8% mol acid axetic ,thu c sanpham nh co nong o 0.5% mol acid axetic vi nng odung dch ay acid axetic la 30%.

Em chan thanh cam n cac qu thay co bo mon May &Thiet B, cac ban sinh vien a giup em hoan thanh oan nay. Tuy nhien, trong qua trnh hoan thanh o ankhong the khong co sai sot, em rat mong qu thay co

gop y, ch dan.

3

9

7374757677787980818283848586

87888990919293949596

979899

100101102103104105106

107108109110111112113114115116

117118

10


4/77


4

13

119120121

14


5/77


CHNG I : TONG QUAN.

I . LY THUYET VE CHNG CAT:1 . Phng phap chng cat :

Chng cat la qua trnh phan tach hon hp long (hoackh long) thanh cac cau t rieng biet da vao s khacnhau ve o bay hi cua chung (hay nhiet o soi khacnhau cung ap suat), bang cach lap i lap lai nhieulan qua trnh bay hi - ngng tu, trong o vat chat i tpha long vao pha hi hoac ngc lai. Khac vi co ac,chng cat la qua trnh trong o ca dung moi va chat taneu bay hi, con co ac la qua trnh trong o ch codung moi bay hi.

Khi chng cat ta thu c nhieu cau t va thng thbao nhieu cau t se thu c bay nhieu san pham.Neu xet he n gian ch co 2 he cau t th ta thuc 2 san pham: san pham nh chu yeu gom gomcau t co o bay hi ln (nhiet o soi nho ), sanpham ay chu yeu gom cau t co o bay hibe(nhiet o soi ln) .oi vi he acid axetic - nc sanpham nh chu yeu gom nc va mot t acid axetic ,ngc lai san pham ay chu yeu gom acid axetic vamot t nc.

Cac phng phap chng cat: c phan loai theo: Ap suat lam viec : chng cat ap suat thap, apsuat thng va ap suat cao. Nguyen tac cuaphng phap nay la da vao nhiet o soi cua caccau t, neu nhiet o soi cua cac cau t qua caoth ta giam ap suat lam viec e giam nhiet osoi cua cac cau t.

Nguyen ly lam viec: lien tuc, gian oan(chng ngian) va lien tuc.* Chng cat n gian(gian oan): phng phap nay

uc s dung trong cac trng hp sau:+ Khi nhiet osoi cua cac cau t khac xa nhau.+ Khong oi hoi san pham co o tinh khiet cao.+ Tach hon hp long ra khoi tap chat khong bay

hi.+ Tach s bo hon hp nhieu cau t.

* Chng cat hon hp hai cau t (dung thiet b hoatong lien tuc) la qua trnh c thc hien lien tuc,nghch dong, nheu oan.

5

17

122123

124

125

126127128129130131132133134135136137138139140141142143144

145146147148149150151

152153154

155156157158159160161162163

18


6/77


Phng phap cap nhiet ay thap: cap nhiet trctiep bang hi nc: thng c ap dung trng hpchat c tach khong tan trong nc .

Vay: oi vi he acid axetic Nc, ta chon phngphap chng cat lien tuc cap nhiet gian tiep bang noiun ap suat thng.

6

21

164165166167168169170

22


7/77


2 . Thiet b chng cat:Trong san xuat thng s dung rat nhieu loai thap

nhng chung eu co mot yeu cau c ban la dien tchbe mat tiep xuc pha phai ln ,ieu nay phu thuoc

vao o phan tan cua lu chat nay vao lu chat kia .Thap chng cat rat phong phu ve kch c va ngdung ,cac thap ln nhat thng c ng dung trongcong nghiep loc hoa dau. Kch thc cua thap : ngknh thap va chieu cao thap tuy thuoc suat lng phalong, pha kh cua thap va o tinh khiet cua san pham.Ta khao sat 2 loai thap chng cat thng dung la thapmam va thap chem.

Thap mam: than thap hnh tru, thang ng phatrong co gan cac mam co cau tao khac nhau e

chia than thap thanh nhng oan bang nhau, trenmam pha long va pha hi c cho tiep xuc vi nhau.Tuy theo cau tao cua a, ta co:

* Thap mam chop : tren mam co chop dang tronhay mot dang khac,co ranh xung quanh e pha kh iqua va ong chay chuyen co hnh tron

* Thap mam xuyen lo: tren mam bo tr cac loco ng knh 3-12mm c bo tr tren cac nh tamgiac,bc lo bang 2,5 en 5 lan ng knh Thap chem(thap em): thap hnh tru, gom nhieu

oan noi vi nhau bang mat bch hay han. Vat chemc cho vao thap theo mot trong hai phng phap:xep ngau nhien hay xep th t.

So sanh u va nhc iem cua cac loaithap :

Thap

chem.Thap mam

xuyen lo.Thap mamchop.

uiem: - n gian.

- Hieu suat tngoi cao. - Hieu suat cao.

- Tr lc

thap.

- Hoat ong kha

on nh.

- Hoat ong on

nh.- Lam viec vichat long ban.

Nhciem:

- Hieu suatthap.

- Tr lc kha cao. - Cau tao phctap.

7

- Thiet bnang.

- Khong lamviec vi chatlong ban.

- o on nhkem.

- Yeu cau lapat khat khe ->lap a thatphang. - Tr lc ln.

25

171172173174175176177178179180181182183184

185186187188189190191192193194

195196197

198199

200

26


8/77


8

29

201

30


9/77


Nhan xet: thap mam xuyen lo la trang thaitrung gian gia thap chem va thap mam chop. Nenta chon thap chng cat la thap mam xuyen lo.

Vay: Chng cat he acid axetic - Nc ta dung thapmam xuyen lo hoat ong lien tuc ap suat thng,cap nhiet gian tiep ay thap.

II . GII THIEU S BO NGUYEN LIEU:Nguyen lieu la hon hp acid axetic - Nc.

1 . Etanol:(Con goi la ru etylic , con etylic hay conthc pham).

Etanol co cong thc phan t: CH3-CH2-OH, khoi lngphan t: 46 vC. La chat long co mui ac trng, khongoc, tan nhieu trong nc.

Mot so thong so vat ly va nhiet ong cua etanol:

+ Nhiet o soi 760(mmHg): 78.3oC.+ Khoi lng rieng: d420 = 810 (Kg/m3).Tnh chat hoa hoc:

Tat ca cac phan ng hoa hoc xay ra nhomhydroxyl (-OH) cua etanol la the hien tnh chat hoahoc cua no.

* Phan ng cua hydro trong nhom hydroxyl:CH3-CH2-OH CH3-CH2-O- + H+

Hang so phan ly cua etanol: 181023

=OHCHCHK , cho

nen etanol la chat trung tnh.+ Tnh acid cua ru the hien qua phan ng vikim loai kiem, Natri hydrua(NaH), Natri amid(NaNH2):

CH3-CH2-OH + NaH CH3-CH2-ONa + H2Natri etylat

Do 1410223

=< OHOHCHCH KK : tnh acid cua ru nho

hn tnh acid cua nc, nen khi muoi Natri etylat tantrong nc se b thuy phan thanh ru tr lai.

+ Tac dung vi acid tao ester: Ru etanol co tnhbaz tng ng vi nc. Khi ru tac dung vi

acid vo c H2SO4, HNO3 va acid hu c eu tao raester.

CH3-CH2-OH + HO-SO3-H CH3-CH2O-SO3-H+ H2O

CH3-CH2O-H + HO-CO-CH3 CH3-COO-C2H5 +H2O

* Phan ng tren nhom hydroxyl:+ Tac dung vi HX: CH3-CH2-OH + HX CH3-

CH2-X + H2O+ Tac dung vi Triclo Phot pho:

9

Lanh

H+

33

202203204205206207

208209

210211212213214

215

216217

218219220221222223

224

225226227228229

230

231232233234

235236237238239240241242243244

245

34


10/77


CH3-CH2-OH + PCl3 CH3-CH2-Cl + POCl + HCl

+ Tac dung vi NH3: CH3-CH2-OH + NH3C2H5-NH2 + H2O

+ Phan ng tao eter va tach loai nc:

2CH3-CH2-OH (CH3-CH2)2O + H2O

CH3-CH2-OH CH2=CH2 + H2O

* Phan ng hydro va oxy hoa:

CH3-CH2-OH CH3-CHO + H2

ng dung: etanol co nhieu ng dung hn metanol, noong mot vai tro quan trong trong nen kinh te quocdan. No la nguyen lieu dung e san suat hn 150mat hang khac nhau va c ng dung rong raitrong cac nganh: cong nghiep nang, y te va dc,quoc phong, giao thong van tai, det, che bien gova nong nghiep.

S o tom tat v tr cua etanol trong cacnganh cong nghiep.

Phng phap ieu che: co nhieu phng phap ieuche etanol: hydrat hoa etylen vi xuc tac H2SO4; thuyphan dan xuat halogen va ester cua etanol khi unnong vi nc xuc tac dung dch baz; hydro hoaaldyhyt acetic; t cac hp chat c kim

10

Al2O

3

to

H2SO

4

>150o

CH2SO

4

>150o

C

Cu200-300oC

+ Thuoc sung khongkhoi.

+ ong lc.+ Thuoc trsau.

+ Sn.+Vecni.

+ o nha.+ Keo dan.+ Hnglieu.

+ Sat trung.+ Pha chethuoc.

+ Thuocnhuom.+ T nhan

tao.

+ Rumui.+ Dam.

+ Dung moi huc:pha sn..+ Nguyen lieu.

+ Cong nghiep cao sutong hp+ ong lc.

Nhienlieu.

Etanol

37

246247248249250251252253254255256257258259

260261262263264265266267268269

270271272273274275276277278279280

281282283284285286287288289290

38


11/77


Trong cong nghiep, ieu che etanol bang phngphap len men t nguon tinh bot va r ng. Nhngnam gan ay, nc ta cong nghe san suat etanolchu yeu la s dung chung nam men Saccharomysescerevisiae e len men tinh bot:

C6H6O6 2C2H5OH + 2CO2 + 28 Kcal

Trong o: 95% nguyen lieu chuyen thanh etanolva CO2.

5% nguyen lieu chuyen thanh san phamphu: glyxerin, acid sucxinic, dau fusel, metylic vacac acid hu c(lactic, butylic).

2 . Nc:Trong ieu kien bnh thng: nc la chat long khong

mau, khong mui, khong v nhng khoi nc day se comau xanh nhat.Khi hoa ran no co the ton tai dang 5 dang tinh

the khac nhau:Khoi lng phan t : 18 g / molKhoi lng rieng d40 c : 1 g / mlNhiet o nong chay : 00CNhiet o soi : 1000 C

Nc la hp chat chiem phan ln tren trai at (3/4dien tch trai at la nc bien) va rat can thiet cho s

song.Nc la dung moi phan cc manh, co kha nang hoatan nhieu chat va la dung moi rat quan trong trong kythuat hoa hoc.3 . Hon hp Etanol Nc:

Ta co bang thanh phan long (x) hi (y) va nhiet osoi cua hon hp Etanol - Nc 760 mmHg:

11

x(%phanmol) 0 5 10 20 30 40 50 60 70 80 90 100

y(%phan

mol) 0 9.2 16.7 30.3 42.5 53 62.6 71.6 79.5 86.4 93 100t(oC) 118.4 115.4 113.8 110.1 107.5 105.8 104.4 103.3 102.1 101.3 100.6 100

Nammen

Zymaza

41

291292293294295296297298299300301302

303304

305306307308309310311312313314

315316317318

319320321

322

42


12/77


0 0

5 9.2 0

10 16.7 10

20 30.3 20

30 42.5 30

40 53 40

50 62.6 50

60 71.6 60

70 79.5 70

80 86.4 80

90 93 90

100 100 100

92

99.5

920

10

20

30

40

50

60

70

80

90

100

X(% mol

Y(%mol)

12

45

323

46


13/77


III. CONG NGHE CHNG CAT HE ETANOL NC:

Etanol la mot chat long tan vo han trong H2O, nhiet osoi la 78,30C 760mmHg, nhiet o soi cua nc la

100o

C 760mmHg : hi cach biet kha xa nen phng phaphieu qua e thu etanol co o tinh khiet cao la phngphap chng cat.

Trong trng hp nay, ta khong the s dung phngphap co ac v cac cau t eu co kha nang bay hi,va khong s dung phng phap trch ly cung nh phngphap hap thu do phai a vao mot khoa mi e tach,co the lam cho qua trnh phc tap hn hay qua trnh tachkhong c hoan toan.

* S o qui trnh cong nghe chng cat he Etanol

nc:Chu thch cac k hieu trong qui trnh:1 . Bon cha nguyen lieu.2 . Bm.3 . Bon cao v.4 . Lu lng ke.5 . Thiet b trao oi nhiet vi san pham ay.6 . Thiet b gia nhiet nhap lieu.7 . Bay hi.8 . Thap chng cat.

9 . Nhiet ke.10 . Ap ke.11 . Thiet b ngng tu san pham nh.12 . Noi un.13 . Thiet b lam nguoi san pham nh.14 . Bon cha san pham nh.15 . Bon cha san pham ay.16 . Bo phan phan dong.

13

49

325

326327328

329330331332333334335336337338

339340341342343344345346347348

349350351352353354355356357358

359360361362363364365366367368369370

50


14/77


14

53

371372373374375

376377378

54


15/77


ang

LI MAUCHNG I : TONG

I .LYTHUYET VE1 .Phng phap c

2 .Thiet bchngII .GII THIEU S1 . Acid axetic

15

57

379380

58


16/77


16

61

381382383384385

386387388389390391392393394395396397398399400401402403404405406

407

62


17/77


* Thuyet minh qui trnh cong nghe:Hon hp etanol nc co nong o etanol 10% ( theo

phan mol), nhiet o khoang 280C tai bnh cha nguyenlieu (1) c bm (2) bm len bon cao v (3). T o ca en thiet b trao oi nhiet (5) ( trao oi nhiet visan pham ay ). Sau o, hon hp c un soi ennhiet o soi trong thiet b gia nhiet(6), hon hp ca vao thap chng cat (8) a nhap lieu.

Tren a nhap lieu, chat long c tron vi phanlong t oan cat cua thap chay xuong. Trong thap hi,i t di len gap chat long t tren xuong. ay,co s tiep xuc va trao oi gia hai pha vi nhau. Phalong chuyen ong trong phan chng cang xuong dicang giam nong o cac cau t de bay hi v a b pha

hi tao nen t noi un (12) loi cuon cau t de bayhi.Nhiet o cang len tren cang thap, nen khi hi i quacac a t di len th cau t co nhiet o soi cao lanc se ngng tu lai, cuoi cung tren nh thap ta thuc hon hp co cau t etanol chiem nhieu nhat (conong o 85% phan mol). Hi nay i vao thiet b ngng tu(11) va c ngng tu hoan toan. Mot phan chat longngng tu i qua thiet b lam nguoi san pham nh (13),c lam nguoi en 350C , roi c a qua bon chasan pham nh (14). Phan con lai cua chat long ngng

tu c hoan lu ve thap a tren cung vi t sohoan lu toi u. Mot phan cau t co nhiet o soi thapc boc hi, con lai cau t co nhiet o soi cao trongchat long ngay cang tang. Cuoi cung, ay thap tathu c hon hp long hau het la cac cau t kho bayhi ( nc). Hon hp long ay co nong o etanol la0,11 % phan mol, con lai la nc. Dung dch long ay ira khoi thap vao noi un (12). Trong noi un dung dchlong mot phan se boc hi cung cap lai cho thap e tieptuc lam viec, phan con lai ra khoi noi un c trao oi

nhiet vi dong nhap lieu trong thiet b (5) (sau khi quabon cao v).He thong lam viec lien tuc cho ra san pham nh la

etanol, san pham ay sau khi trao oi nhiet vi nhaplieu co nhiet o la 600C c thai bo.

17

65

408409410411412413414415416417418419420421422423424425426427428429430431

432433434435436437438439440441

442443444445446

447448449450451

66


18/77


CHNG II : CAN BANG VATCHAT .

I . CAC THONG SO BAN AU : Nang suat nhap lieu:

(x

=x1*M1/(x1*M1+(1-x1)*M2)=(0.08*60)/(0.08*60+0.92*18)=20/89=0.2247

1/nat b

xx /)1(/ += =20/89/1039.6+(1-20/89)/995.6, tb

=1005.16kg/m3) GF=QF* tb =5*1005.16=5025.8(kg/h).

Nong o nhap lieu : xF = 8% mol acid axetic(xF=0.92)

Nong o san pham nh : xD = 0.5% mol acidaxetic( xD=0.995)

Nong o san pham ay : xW = 30% mol acid axetic.(xW=0.7) Khoi lng phan t cua acid axetic va nc : MA =60

kg/kmol , MN =18 kg/kmol . Chon :

+ Nhiet o nhap lieu : tF =28oC .+ Nhiet o san pham nh sau khi lam nguoi : tD

=35oC .+ Nhiet o san pham ay sau khi trao oi nhiet : tW

= 35oC .+Trang thai nhap lieu la trang thai long soi .

Cac k hieu :+ GF , F : suat lng nhap lieu tnh theo Kg/h , Kmol/h .+ GD , D : suat lng san pham nh tnh theo Kg/h ,

Kmol/h .+ GW ,W : suat lng san pham ay tnh theo Kg/h ,

Kmol/h .+ xi , ix : phan mol , phan khoi lng cua cau t i .

II . XAC NH SUAT LNG SAN PHAM NH

VA SAN PHAM AY:

18

69

452453454455456

457

458

459

460461

462

463

464465

466

467468469470471472

473474475476

477478479480481482

483484485486487488489490

491

492

70


19/77


Can bang vat chat cho toan thap : F = D + W(II.1)

Can bang cau t : F.xF = D.xD + W.xW (II.2)Vi : * Phan mol nhap lieu : xF = 8%(phan mol acid

axetic ).Khoi lng phan t trung bnh dong nhap lieu :MF = 18).1(.60 FF xx + = 21.36 (Kg/Kmol).

F =F

F

M

G=

36.21

8.5025=235.29 (Kmol/h)

*Phan mol san pham nh : xD =0,5% (phan molacid axetic) .

Khoi lng phan t trung bnh dong san pham

ay :

MW = 18).1(.60 WW xx + = 30.6 (Kg/Kmol).Khoi lng phan t trung bnh dong san phamnh :

MD = 18).1(.60 DD xx + =18.21 (Kg/Kmol).Giai 2 phng trnh (II.1),(II.2)ta co :

19

73

493494495496497498499

500

501502503504505

506507508509510

74


20/77


D =175.47 (Kmol/h)W = 59.819 (Kmol/h)

III . XAC NH T SO HOAN LU THCH HP :

1 . T so hoan lu toi thieu:T so hoan lu toi thieu la che o lam viec ma taio ng vi so mam ly thuyet la vo cc .Do o ,chi phco nh la vo cc nhng chi ph ieu hanh (nhien lieu,nc va bm) la toi thieu .

Do o th can bang cua he acid axetic -Nc co iemuon ,nen xac nh t so hoan lu toi thieu bang cach :

+Tren o th can bang y-x ,t iem (0.995,0.995) take mot ng thang i qua iem (xF,y*F) cat truc Oy taiiem co yo = 0.32.

+Theo phng trnh ng lam viec oan cat , khi xo =0th

yo =1min +R

xD =0.32

Vay : t so hoan lu toi thieu : Rmin = 2.109or

Rmin=

xy

yx

FF

FD

*

*=

92.0945.0

945.0995.0

=2

T so hoan lu thch hp:RX=1.3Rmin+0.3=2.92. T so hoan lu thch hp:

Khi R tang, so mam se giam nhng ng knh thap,thiet b ngng tu ,noi un va cong e bm cung tangtheo.Chi ph co nh se giam dan en cc tieu roi tangen vo cc khi hoan lu toan phan ,lng nhiet va lngnc s dung cung tang theo t so hoan lu .

Tong chi ph bao gom : chi ph co nh va chi ph ieuhanh . T so hoan lu thch hp ng vi tong chi ph lacc tieu .

Tuy nhien ,oi khi cac chi ph ieu hanh rat phctap ,kho kiem soat nen ngi ta co the tnh t so hoanlu thch hp t ieu kien thap nho nhat .e tnh ct so hoan lu thch hp theo ieu kien thap nho nhat(khong tnh en chi ph ieu hanh),ta can lap moi quanhe gia t so hoan lu va the tch thap ,t o chon Rthng vi the tch thap la nho nhat.

Nhan thay ,tiet dien thap t le vi lng hi i trongthap ,ma lng hi lai t le vi lng long hoi lu trong

20

77

511512513

514

515516517518519520521522523524

525526

527

528529

530

531

532533534535536537538539540541542543544545546547

548549

78


21/77


thap ,do trong ieu kien lam viec nhat nh th GD sekhong oi nen lng long hoi lu se t le vi (R+1) ,doo , tiet dien thap se t le vi (R+1). Ngoai ra ,chieucao thap t le vi so n v chuyen khoi mox hay somam ly thuyet Nlt .Cho nen ,the tch lam viec cua thapt le vi tch so mox*(R+1) .Nh vay, ta co the thiet lapquan he gia R va Vthap theo quan he R va mox*(R+1) .To th cua quan he nay ,ta xac nh c iem cc tieucua mox*(R+1) ng vi t so hoan lu thch hp R .

R mox mox*(R+1)

2.496 47.818 167.173

2.723 37.733 140.480

2.973 32.801 130.320

3.023 33.545 134.952

120

130

140

150

160

170

2.00 2.50 3.00 3.50

R

R*(mox+1)

Vay : T so hoan lu thch hp la R= 2,973 .IV . PHNG TRNH NG LAM VIECSO

MAM LY THUYET:1 . Phng trnh ng nong o lam vieccua oan cat :

y =1

.1

.

++

+ Rx

xR

R D =19,2

995,0.

19,2

9,2

++

+x

=0,7436.x + 0.25512 . Phng trnh ng nong o lam viec

cua oan chng :

y = WxR

fx

R

fR.

1

1.

1 +

+

+

+= 7.0.

19,2

1341.1.

19,2

341.19,2

+

+

+

+x

= 1.087x 0.0612

21

81

550551552553554555556557558559

560

561562

563

564565

566

567

568

569

570

571

572

82


22/77


Vi : f =47.175

29.235=

D

F= 1.341 : ch so nhap lieu .

3 . So mam ly thuyet :o th xac nh so mam ly thuyet :(Xem hnh trang

sau ).

T o th ,ta co : 29 mam bao gom : 19 mam cat

1 mam nhap lieu

22

85

573

574575576577578579580581582583584585586587588589590591592593594595

596597598599600601602603604605

606607608609610611612613614615

616

86


23/77


5 mam chng(4 mamchng+1 noi un)Tom lai ,so mam ly thuyet la Nlt = 28 mam .

V . XAC NH SO MAM THC TE:

So mam thc te tnh theo hieu suat trung bnh :

tb

lt

tt

NN = (st2/170)

trong o: tb : hieu suat trung bnh cua a, la motham so cua o bay hi tng oi va o nht cua honhp long : = f( , ).

Ntt : so mam thc te.

Nlt : so mam ly thuyet.

Xac nh hieu suat trung bnh cua thap tb :+ o bay tng oi cua cau t de bay hi :

x

x1

y1

y*

*

=

Vi : x :phan mol cua nc trong pha long .y* : phan mol cua nc trong pha hi can bang

vi pha long.* Tai v tr nhap lieu :

xF = 0.92 ta tra o th can bang cua he : y*F =0.945

tF = 100.52 oC

+92.0

92.01.

945.01

945.0

x

x1

y1

y

F

F

*

*

F

=

=F

F= 1.494

+ T %12,22=Fx va tF = 100.52 oC ,tra tai lieu thamkhao [4(tap 1) trang 107] : F =43.10-6.9,81 =0,422.10-3 (N.s/m2)

= 0,422 (cP)Suy ra : F . F = 7,129.0,422 =3,007

Tra tai lieu tham khao [4(tap 2) trang 171] : F =

0,395* Tai v tr mam ay :xW = 0.7 ta tra o th can bang cua he : y*W = 0.795

tW = 102.1 oC

+7.0

7.01.

795.01

795.0

x

x1

y1

y

W

W

*

*

W

=

=

W

W= 1.662

+ T %29,018).1(.46

.46=

+=

WW

W

Wxx

xx va tW = 100 oC ,tra tai

lieu tham khao [4(tap 1) trang 107] :

W =25.10-6

.9,81= 0,245.10-3

(N.s/m2

)= 0,245 (cP)

23

89

617618619

620621

622

623624

625626

627

628

629

630

631632633634635636637

638

639

640641642

643

644645646647648

649

650

651

652653

90


24/77


Suy ra : W . W = 16,177.0,245 = 3,967Tra tai lieu tham khao [4(tap 2) trang 171] : W =

0,365*Tai v tr mam nh :

xD = 0.995 ta tra o th can bang cua he : y

*

D =0.997tD = 100.22 oC

+995.0

995.01.

997.01

997.0

x

x1

y1

y

D

D

*

*

D

=

=

D

D

= 1.67

+ T %5,9318).1(.46

.46=

+=

DD

D

Dxx

xx va tD = 78,5 oC ,tra tai

lieu tham khao [4(tap 1) trang 107] : D =51.10-6.9,81= 0,500.10-3 (N.s/m2)

= 0,500 (cP)Suy ra : D . D = 1,049.0,500 = 0,525Tra tai lieu tham khao [4(tap 2) trang 171] : D =

0,600Suy ra: hieu suat trung bnh cua thap :

tb = 4567,03

600,0365,0395,0

3=

++=

++ DWF

So mam thc te cua thap Ntt :

4567,0

28=ttN =52,55 mam

Vay chon Ntt = 53 mam , gom : 42 mam cat1 mam nhap lieu10 mam chng

24

93

654

655656657658659660

661

662

663

664

665666

667668669

670

671

672

673674675676677678679680681682

683684685686

94


25/77


CHNG III :TNH TOAN THIETKE THAP CHNG CAT .

I . NG KNH THAP :(Dt)

tbyytbg).(

0188,0.3600.

4VDtb

tbt

== (m)(t2 tr181)

Vtb :lng hi trung bnh i trong thap (m3/h). tb :toc o hi trung bnh i trong thap (m/s).gtb : lng hi trung bnh i trong thap (Kg/h).

Lng hi trung bnh i trong oan chng va oan catkhac nhau.Do o, ng knh oan chng va oan catcung khac nhau .

1. ng knh oan cat :a . Lng hi trung bnh i trong thap :

2

1ggg dtb+

= (Kg/h)

gd : lng hi ra khoi a tren cung cua thap (Kg/h).g1 : lng hi i vao a di cung cua oan cat

(Kg/h). Xac nh gd : gd = D.(R+1) =175.47(2,9+1) = 684.333

(Kmol/h)= 40973.75(Kg/h)(V MthD =60.yD+(1-yD).18 = 59.874Kg/Kmol).

Xac nh g1 :T he phng trnh :

=

+=

+=

dd

D

rgrg

xDxGyg

DGg

..

...

11

1111

11

(III.1)

Vi : G1 : lng long a th nhat cua oan cat .r1 : an nhiet hoa hi cua hon hp hi i vao a

th nhat cua oan cat

rd : an nhiet hoa hi cua hon hp hi i ra nh thap .* Tnh r1 : t1 = tF = 100.52oC , tra tai lieu tham khao [4

(tap 1)] ta co :An nhiet hoa hi cua nc : rN1 = 40512.96

(KJ/kmol) .An nhiet hoa hi cua acid : rR1 = 24195.24 (KJ/kmol) .Suy ra : r1 = rR1.y1 + (1-y1).rN1 = 40512.96 16317.72y1

(KJ/kmol)* Tnh rd : tD = 100.22oC , tra tai lieu tham khao IV (tap

1) ta co :

25

97

687

688

689

690

691

692693694695696

697698

699

700701702703704705706

707

708

709710711

712713714715716717718719720721

722

98


26/77


An nhiet hoa hi cua nc : rNd = 40512.96(KJ/kmol) .

An nhiet hoa hi cua acid : rRd = 24195.24(KJ/kmol) .Suy ra : rd = rRd.yD + (1-yD).rNd =24195.24*0.997 + (1-

0.997)*40512.96= 24244.193 (KJ/kmol)

* x1 = xF = 0.92Giai he (III.1) , ta c : G1 = 483.96 (Kmol/h)

y1 = 0.647 (phan mol acid) _ M1=45.174

g1 = 958.43 (Kmol/h) = 43297.02(Kg/h)

Vay : gtb =2

02.4329775.40973 +=42135.38(Kg/h)

b . Toc o hi trung bnh i trong thap :Toc o gii han cua hi i trong thap vi mam xuyen

lo co ong chay chuyen :

ytb

xtbgh

.05,0=

Vi : xtb : khoi lng rieng trung bnh cua pha long(Kg/m3) .

ytb : khoi lng rieng trung bnh cua pha hi(Kg/m3) . Xac nh ytb :

( )[ ]( )273.4,22

273.18.160.

++

=tb

tbtbytbt

yy

Vi: + Nong o phan mol trung bnh : ytb =2

1 Dyy + =

2

997.0647.0 +=0.822

+ Nhiet o trung bnh oan cat : ttb =2

DF tt + =

2

22.10052.100 +=100.37oC

Suy ra : ytb =1.745 (Kg/m3). Xac nh xtb :

Nong o phan mol trung bnh : xtb =2

DF xx + =2

099592.0 +=

0.4577

Suy ra :18).1(.60

.60

tbtb

tb

tbxx

xx

+= =0.7378 .

ttb = 100.37oC , tra tai lieu tham khao [4 (tap 1)-trang 9],ta co :

a=958kg/m

3

n =958 kg/m

3

26

101

723724725726727728729730731732733

734

735736737

738

739740

741742

743

744

745

746

747

748

749750

751

752

753

754755

756

102


27/77


1/nat b

xx /)1(/ +=

xtb = 958 (Kg/m3)

Suy ra :745.1

958.05,0=gh =1.172 (m/s)

e tranh tao bot ta chon toc o hi trung bnh i trongthap :

172.1.8,0.8,0 == ghh = 0.9376 (m/s)Vay :ng knh oan cat :

Dcat =9376.0.745.1

38.42135.0188,0 = 3.017 (m).

2. ng knh oan chng :a . Lng hi trung bnh i trong thap :

2

1,,

, gg

g

ntb

+

= (Kg/h)gn : lng hi ra khoi oan chng (Kg/h).g1 : lng hi i vao oan chng (Kg/h).

Xac nh gn : gn = g1 = 561,873 (Kg/h) Xac nh g1 :T he phng trnh :

==

+=

+=

1111

1'

11'

1'

1'

.'.''.'

..'.

rgrgrg

xWygxG

WgG

nn

WW(III.2)

Vi : G1 : lng long a th nhat cua oan chng .r1 : an nhiet hoa hi cua hon hp hi i vao a

th nhat cua oan chng.* Tnh r1 : xW =0,0011 tra o th can bang cua he ta

co : yW =0,018Suy ra :Mtbg =46.yW +(1-yW).18=18,504 (Kg/kmol)t1 = tW = 100oC , tra tai lieu tham khao [4 (tap 1)],

ta co :An nhiet hoa hi cua nc : rN1 = 40680

(KJ/kmol) .An nhiet hoa hi cua ru : rR1 = 36394,3

(KJ/kmol) .Suy ra : r1 = rR1.yW + (1-yW).rN1 = 40543,9 (KJ/kmol)

* Tnh r1: r1 = 41280 3885.y1 =412803885.0,297=40126,155(KJ/kmol)

* W = 42,477 (Kmol/h)Giai he (III.2) , ta c : x1 =0,0067(phan mol etanol) _

MtbG =18,189 G1 = 63,608 (Kmol/h) =

27

105

757

758

759

760761762763

764

765766

767

768769770771

772

773774775776777778779780

781782783784785786787788789790791

106


28/77


g1 = 21,131 (Kmol/h) = 391,008(Kg/h)

Vay : gtb = 441,4762

008,391873,561=

+(Kg/h)

b . Toc o hi trung bnh i trong thap :Toc o gii han cua hi i trong thap vi mam xuyen

lo co ong chay chuyen :

ytb

xtbgh

'

'.05,0'

=

Vi : 'xtb : khoi lng rieng trung bnh cua pha long(Kg/m3) .

'ytb : khoi lng rieng trung bnh cua pha hi(Kg/m3) . Xac nh ytb :

( )[ ]( )273'.4,22

273.18.'146.'

' +

+

= tbtbtb

ytbt

yy

Vi: + Nong o phan mol trung bnh :

ytb =2

1 Wyy + =2

018,0297,0 +=0,1575

+ Nhiet o trung bnh oan chng : ttb =2

WF tt + =

2

1005,86 +=93,25oC

Suy ra : ytb =0,746 (Kg/m3).

Xac nh xtb :Nong o phan mol trung bnh : xtb =

2

WF xx + =2

0011,010,0 +

= 0,051

Suy ra :18).'1('.46

'.46'

tbtb

tb

tbxx

xx

+= =11,98% .

ttb = 93,25oC , tra tai lieu tham khao [4 (tap 1)-trang9], ta co :

Khoi lng rieng cua nc : N = 963,117(Kg/m3)

Khoi lng rieng cua ru : R = 720,365(Kg/m3

)Suy ra : xtb =

1

'

'1

'

'

+

N

tb

R

tb xx

=925,744 (Kg/m3)

Suy ra :746,0

744,925.05,0' =gh =1,762 (m/s)

e tranh tao bot ta chon toc o hi trung bnh i trongthap :

762,1.8,0'.8,0' == ghh = 1,409 (m/s)Vay :ng knh oan cat :

Dchng= 409,1.746,0441,476

.0188,0 = 0,400 (m).

28

109

792

793

794795

796

797

798799

800801

802

803

804

805

806

807

808

809

810

811

812

813814

815

816817

818

819820821822

823

110


29/77


Ket luan : hai ng knh oan cat va oan chngkhong chenh lech nhau qua ln nen ta chon ng knhcua toan thap la : Dt = 0,500 (m).

Khi o toc o lam viec thc :

+ Phan cat : lv = 903,0171,1.5,0768,747.0188,0

.

.0188,02

2

2

2

==ytbt

tb

D

g

(m/s).

+ Phan chng : lv = 903,0746,0.5,0

441,476.0188,0

'.

'.0188,02

2

2

2

==ytbt

tb

D

g

(m/s).II . MAM LO TR LC CUA MAM :1 . Cau tao mam lo :

Chon : + ng knh lo : dl = 3 (mm).+ Tong dien tch lo bang 9,77% dien tch mam.

+ Khoang cach gia hai tam lo bang 2,5 lanng knh lo (bo tr lo theo tam giac eu ).

+ Ty le be day mam va ng knh lo la 6/10 .+ Dien tch danh cho ong chay chuyen la 20%

dien tch mam .So lo tren 1 mam :

N =lo

mm

S

%.77,9 S=

22

003,0

5,0.0977,0.0977,0

=

l

t

d

D~2716 lo.

Vay: ta bo tr cac lo tren 1 mam thanh 51(hang), so

lo tren ng cheo la 66 lo.2 . o giam ap cua pha kh qua mot mam :o giam ap tong cong cua pha kh (tnh bang

mm.chat long ) la tong cac o giam ap cua pha khqua mam kho va cac o giam ap do pha long :

htl = hk + hl + hR (mm.chat long)Vi : + hk :o giam ap qua mam kho (mm.chat

long).+ hl : o giam ap do chieu cao lp chat long

tren mam(mm.chat long).

+hR : o giam ap do sc cang be mat(mm.chat long).

Trong thap mam xuyen lo ,gradien chieu cao mcchat long tren mam la khong ang ke nen co thebo qua .a . o giam ap qua mam kho :

o giam ap cua pha kh qua mam kho c tnh datren c s ton that ap suat do dong chay ot thu ,ot m va do ma sat khi pha kh chuyen ong qua lo.

29

113

824825826827

828

829

830

831

832833834

835836837838839840

841

842

843844845846847848849850851852

853854855

856857858859860861

114


30/77


L

G

o

o

L

G

o

ok

C

u

gC

vh

..0,51

..2.

2

2

2

2

=

= (mm.chat long)

Vi : + uo :van toc pha hi qua lo (m/s).+ G : khoi lng rieng cua pha hi (Kg/m3).+ L : khoi lng rieng cua pha long (Kg/m3).+ Co :he so orifice ,phu thuoc vao ty so tong

dien tch lo vi dien tch mam va ty so gia beday mam vi ng knh lo.

Ta co :mmS

Slo =0,0977 val

mm

d

=0,6 .Tra tai lieu

tham khao [1 trang 111] : Co = 0,745 oi vi mam phan cat :

+ Van toc pha hi qua lo : uo = 0977,0903,0

%77,9 =lv

=9,243(m/s).

+ Khoi lng rieng cua pha hi : G = ytb = 1,171(Kg/m3).

+ Khoi lng rieng cua pha long : L = xtb =821,25 (Kg/m3).

Suy ra o giam ap qua mam kho phan cat :

25,821

171,1.

745,0

243,9.0,51

2

2

=kh =10,683 (mm.chat long).

oi vi mam phan chng :+ Van toc pha hi qua lo : uo =

0977,0

903,0

%77,9

'=lv

=9,243

(m/s).+ Khoi lng rieng cua pha hi : G = ytb = 0,746

(Kg/m3).+ Khoi lng rieng cua pha long : L = xtb =

925,744 (Kg/m3).Suy ra o giam ap qua mam kho phan chng :

744,925

746,0.745,0

243,9.0,51' 2

2

=kh = 6,039 (mm.chat long).

b . o giam ap do chieu cao mc chat long trenmam :Phng phap n gian e c tnh o giam ap cua

pha hi qua mam do lp chat long tren mam hl la tchieu cao g chay tran hw , chieu cao tnh toan cua lpchat long tren g chay tran how va he so hieu chnhtheo kinh nghiem :

hl = .( hw + how ) , (mm.chat long)

Chon : + He so hieu chnh : = 0,6

30

117

862

863

864

865866867868

869

870

871

872873

874875

876877878

879

880

881

882

883884

885886887

888

889890891892893894

895

896

897

118


31/77


+ Chieu cao g chay tran : hw = 50 (mm)Chieu cao tnh toan cua lp chat long tren g chay

tran c tnh t phng trnh Francis vi g chay tranphang :

32

.4,43

=

w

Low

Lqh , (mm.chat long)

Vi : + qL : lu lng cua chat long (m3/ph).+ Lw :chieu dai hieu dung cua g chay tran (m).

Xac nh Lw :Dien tch danh cho ong chay chuyen la 20% dien

tch mam , nen ta co phng trnh sau :

.2,0sin180

.= o

o

o

nn

Vi : no :goc tam chan bi chieu dai oan Lw .

Dung phng phap lap ta c : no = 93o1222Suy ra : Lw = Dt . sin(no/2) = 363,305(mm) ~ 364 (mm) =

0,364 (m). Xac nh qL :

* Phan cat :25,821.60

8.41.60,5.973,2

.60

..==

xtb

D

L

MDRq

= 0,01412

(m3/ph).

Suy ra :3

2

364,0

01412,0.4,43

=owh = 4,978 (mm).

Vay :o giam ap do chieu cao mc chat longtren mam phan cat la:hl = 0,6.(50+4,978) = 32,987 (mm.chat long).

* Phan chng :744,925.60

189,18.608,63

'.60

.' '

1'

==xtb

tbG

L

MGq

= 0,02083

(m3/ph).

Suy ra :3

2

364,0

02083,0.4,43'

=

owh = 6,445 (mm).

Vay :o giam ap do chieu cao mc chat long

tren mam phan chng :hl = 0,6.(50+6,445) = 33,867 (mm.chat long).c . o giam ap do sc cang be mat :

o giam ap do sc cang be mat c xac nh theobieu thc :

lL

Rd

h.

.54,625

= , (mm.chat long)

Vi : + : sc cang be mat cua chat long(dyn/cm).

+ L : khoi lng rieng cua pha long (Kg/m3). Phan cat :

31

121

898899900901

902

903904905906907

908

909

910911912913

914

915

916

917918919

920

921

922

923

924925926927928

929

930931

932

933

122


32/77


* Khoi lng rieng cua pha long : L = xtb = 821,25(Kg/m3).

* ttb = 82,5oC ,tra tai lieu tham khao [4 (tap 1)], ta co :+ Sc cang be mat cua nc : N = 62,138

(dyn/cm).+ Sc cang be mat cua ru : R = 17,075(dyn/cm).

Suy ra :Sc cang be mat cua chat long phancat :

RN

RN

+=

.= 13,394 (dyn/cm).

Vay : o giam ap do sc cang be mat phancat la :

003,0.25,821

394,13.54,625=Rh = 3,401 (mm.chat long).

Phan chng :* Khoi lng rieng cua pha long : L = xtb = 925,744

(Kg/m3).* ttb = 93,25oC ,tra tai lieu tham khao [4 (tap 1)], ta

co :+ Sc cang be mat cua nc : N = 60,149

(dyn/cm).+ Sc cang be mat cua ru : R = 16,108

(dyn/cm).Suy ra :Sc cang be mat cua chat long phan

chng :

RN

RN

''

'.''

+= = 12,705 (dyn/cm).

Vay : o giam ap do sc cang be mat phanchng la :

003,0.744,925

705,12.54,625' =Rh = 2,862 (mm.chat long).

Tom lai : o giam ap tong cong cua pha kh qua

mot mam :+ Phan cat : htl = 10,683+32,987+3,401 = 47,071(mm.chat long).

hay htl = 47,071 . 10-3 . 9,81 . 821,25 = 379,226(N/m2).

+ Phan chng : htl = 6,039+33,867+2,862 = 42,768(mm.chat long).

hay htl = 42,768 . 10-3 . 9,81 . 925,744 = 388,400(N/m2).

Suy ra :Tong tr lc cua toan thap hay o giam ap

tong cong cua toan thap la :(xem o giam ap tong

32

125

934935936

937938

939940941942

943

944945

946

947

948949950951

952953

954955956957

958

959960

961

962

963964965966967968969970971972

973

126


33/77


cong cua pha kh qua mam nhap lieu bang o giamap tong cong cua pha kh qua mot mam phanchng )

htl = 42. htl + 11. htl = 42 . 379,226+11 . 388,400 =20199,9(N/m2).

33

129

974975976

977978

130


34/77


3 . Kiem tra ngap lut khi thap hoat ong :Chon khoang cach gia hai mam la hmam =250 (mm).Bo qua s tao bot trong ong chay chuyen, chieu cao

mc chat long trong ong chay chuyen cua mam xuyen

lo c xac nh theo bieu thc :hd = hw + how + htl + hd , (mm.chat long)Vi : hd : ton that thuy lc do dong long chay t

ong chay chuyen vao mam, c xac nh theo bieuthc sau :

2

'.100

.128,0

=

d

Ld

S

Qh , (mm.chat long)

trong o : + QL : lu lng cua chat long (m3/h).+ Sd : tiet dien gia ong chay chuyen va

mam, khi o :Sd = 0,8 . Smam = 0,8 . .0,252 = 0,1571 (m2)

Phan cat : QL = 60.qL = 60 . 0,01412 = 0,8472 (m3/h).

Suy ra :2

'1571,0.100

8472,0.128,0

=dh = 0,0004 (mm.chat long).

Vay : chieu cao mc chat long trong ong chaychuyen cua mam xuyen lo phan cat :

hd =50+4,978+47,071+0,0004 =102,0494(mm.chat long).

Kiem tra : hd = 102,0494 < 1252

250

2

mm ==h

(mm) : am

bao khi hoat ong cac mam phan cat se khong bngap lut.

Phan chng : QL = 60.qL = 60 . 0,02083 = 1,2498 (m3/h).

Suy ra :2

'1571,0.100

2498,1.128,0'

=dh = 0,0008 (mm.chat long).

Vay : chieu cao mc chat long trong ong chaychuyen cua mam xuyen lo phan chng :

hd =50+6,445+42,768+0,0008 =99,2138 (mm.chatlong).

Kiem tra : hd = 99,2138 < 1252

250

2

mm ==h (mm) : am bao

khi hoat ong cac mam phan chng se khong bngap lut.Vay : khi hoat ong am bao thap se khong b

ngap lut.Chieu cao cua than thap :Hthan =Ntt .(hmam+ mam ) +

0,8=53.(0,250+0,0018) +0,8 =14,2(m).

Chieu cao cua ay va nap : H = Hn =ht +hg=0,125+0,025=0,150(m).

34

133

979980981982983984985986987

988

989990991

992993

994

995996997998

999

100010011002

1003

1004100510061007

1008

1009101010111012

10131014101510161017

134


35/77


(Xem phan (III.2) : ay va Nap thiet b ).Chieu cao cua thap : H = Hthan + H + Hn = 14,5(m).

35

137

10181019

138


36/77


III . TNH TOAN C KH CUA THAP :1 . Be day than thap :

V thap chng cat hoat ong ap suat thng nen tathiet ke than hnh tru bang phng phap han giap moi

(phng phap ho quang ). Than thap c ghep vi nhaubang cac moi ghep bch.e am bao chat lng cua san pham va kha nang

an mon cua etylic oi vi thiet b, ta chon vat lieu chetao than thap la thep khong g ma X18H10T. Ap suat tnh toan :

Thap lam viec ap suat kh quyen, nen ta chon apsuat tnh toan :

Ptt =Pcl + htl , (N/mm2)Vi : Pcl : ap suat thuy tnh do chat long ay

(N/mm2).Chon ap suat tnh toan sao cho thap hoat ong

ieu kien nguy hiem nhat ma van an toan nen :

Pcl = x .g.H =2

'xtbxtb + .g.H=2

744,92525,821 +. 9,81 .

14,5=124250,58 (N/m2).

Suy ra : Ptt = 124250,58 + 20199,9 = 144450,48(N/m2)~0,14446(N/mm2).

0.25=25N/cm2

Nhiet o tnh toan :Chon nhiet o tnh toan : ttt = tay = 100oC .Tra tai lieu tham khao [5], ng suat tieu chuan oivi thep X18H10T :

[ ]* = 142 (N/mm2).oi vi ru he so hieu chnh : = 1Vay : ng suat cho phep : [ ] = .[ ]* = 142 (N/mm2).

Xac nh be day than chu ap suat trong :Ta chon phng phap che tao than la phng phap

han ho quang ien bang tay nen he so ben moi han : h = 0,9

Xet ty so :[ ]

95,0.25.0

142. =h

ttP

=539.6 > 25,do o, be day

tnh toan cua than c tnh theo cong thc sau :

[ ] 95,0.142.225.0.2200

..2

.' ==

h

ttt

t

PDS

= 2 (mm).

Suy ra : be day thc cua than : St = St + C ,(mm).Trong o : C :he so bo sung be day, C = Ca + Cb + Cc

+ Co

36

141

1020

102110221023

10241025102610271028

102910301031

10321033

103410351036

1037

10381039104010411042

1043104410451046

1047

1048

1049

10501051

10521053

1054

1055

1056

10571058

1059

142


37/77


Vi : + Ca : he so bo sung do an mon hoa hoc,phu thuoc vao toc o an mon cua chat long.Chon toc o an mon cua ru la 0,1(mm/nam),thiet b hoat ong trong 20 nam, doo Ca = 2 mm.

+Cb : he so bo sung do bao mon c hoc, chonCb = 0.

+Cc : he so bo sung do sai lech khi che tao,chon Cc = 0.

+Co : he so bo sung qui tron, chon Co =0,7174(mm).

Suy ra : C = 2 + 0 + 0 + 0,7174 = 2,7174 (mm).Vay : St = 0,2826 + 2,7174 = 3 (mm).5

* Kiem tra cong thc tnh toan vi St = 3 (mm) :

220025=

t

at

D

CS

= 0,002 < 0,1 : ung.

* Kiem tra ap suat tnh toan cho phep :

[ ] [ ] ( )( )

( )

( )252200

25.95,0.142.2...2

+

=+

=att

ath

ttCSD

CSP

=0,5102 > Ptt :

ung.Vay : Be day thc cua than la St = 3 (mm).

2 . ay va nap thiet b :Chon ay va nap co dang la ellipise tieu chuan, co

g bang thep X18H10T.

Nhan thay: cong thc tnh toan be day than, ay vanap chu ap suat trong la nh nhau. Nen chon be day cuaay va nap la S = Sn = 3 (mm).

Cac kch thc cua ay va nap ellipise tieu chuan, cog(tai lieu tham khao [4(tap 2)]:+ ng knh trong: Dt = 500 (mm).+ ht =125 (mm).+ Chieu cao g: hg = h = 25 (mm).+Dien tch be mat trong: Say = 0,31 (m2).

3 . Bch ghep than, ay va nap :Mat bch la bo phan quan trong dung e noi cac

phan cua thiet b cung nh noi cac bo phan khac vithiet b. Cac loai mat bch thng s dung:

37

145

10601061106210631064106510661067106810691070107110721073

1074

1075

1076

10771078

107910801081

1082108310841085108610871088108910901091

1092109310941095

146


38/77


+ Bch lien: la bo phan noi lien vi thiet b (han,uc va ren). Loai bch nay chu yeu dung thiet b lamviec vi ap suat thap va ap suat trung bnh.

+ Bch t do: chu yeu dung noi ong dan lam viec nhiet o cao, e noi cac bo bang kim loai mau va hpkim cua chung, ac biet la khi can lam mat bch bangvat lieu ben hn thiet b.

+ Bch ren: chu yeu dung cho thiet b lam viec apsuat cao.

Chon bch c ghep than, ay va nap lam bangthep X18H10T, cau tao cua bch la bch lien khong co.

Theo tai lieu tham khao [4 (tap 2)- trang 417], ng viDt =500(mm) va ap suat tnh toan Ptt = 0,14446(N/mm2) tachon bch co cac thong so sau :

Dt D Db D1 h Bu long

db Z

(mm)(cai)

500 630 580 550 20 20 16Theo tai lieu tham khao [4 (tap 2)- trang 170], chon so mam

gia hai mat bch la 4 mam.Vay, so bch ghep than-ay-napla (15.2) bch.

o kn cua moi ghep bch chu yeu do vat em quyetnh. em lam bang cac vat lieu mem hn so vi vat lieubch. Khi xiet bu long, em b bien dang va ien ay len caccho go ghe tren be mat cua bch. Vay, e am bao o kncho thiet b ta chon em la day amiang, co be day la3(mm).4 . ng knh cac ong dan Bch ghep cac

ong dan :Bch c lam bang thep CT3 , cau tao cua bch la bch

lien khong co.

38

149

10961097109810991100110111021103110411051106

1107110811091110

111111121113111411151116111711181119

1120

112111221123

150


39/77


a . V tr nhap lieu :Suat lng nhap lieu: GF = 1000 (Kg/h).Khoi lng rieng cua chat long nhap lieu, tra tai

lieu tham khao [4 (tap 1)] tF = 86,5oC va %12,22=Fx : F = 920,1 (Kg/m3).

Lu lng chat long nhap lieu i vao thap:F

FF

GQ

= =

1,087 (m3/h).Chon van toc chat long nhap lieu (t chay t bon

cao v vao mam nhap lieu): vF = 0,2 (m/s).ng knh ong nhap lieu: dF =

044,02,0..3600

087,1.4

..3600

.4==

F

F

v

Q(m).

Suy ra: chon ng knh ong nhap lieu: dF = 0,050(m).

Tai lieu tham khao [4 (tap 2)], chon chieu dai oanong noi e ghep mat bch: lF = 100 (mm).

Cac thong so cua bch ghep ong dan nhap lieu:Dt Db Dn D D1 h Bu long

db Z

(mm)

(cai)

50 110 57 140 90 12 12 4

b . Ong hi nh thap:Suat lng hi nh thap: gd = 933,662 (Kg/h).Khoi lng rieng cua hi nh thap c tnh theo

cong thc (xac nh tD = 78,5oC va yD = 0,856):

( )[ ]( )273.4,22

273.18.1.46

++

=D

DDh

t

yy = 1,453 (Kg/m3).

Lu lng hi ra khoi thap:h

d

gQh = = 642,483 (m3/h).

Chon van toc hi nh thap: vh = 25 (m/s).

39

153

11241125112611271128

1129

1130

1131113211331134

1135

11361137113811391140

11411142114311441145

1146

1147

1148

154


40/77


ng knh ong dan hi: dh = 095,025..3600

483,642.4

..3600

.4==

h

h

v

Q

(m).Suy ra: chon ng knh ong dan hi: dh = 0,100 (m).

Tai lieu tham khao [4(tap 2)], chon chieu dai oanong noi e ghep mat bch: lh = 120 (mm).Cac thong so cua bch ghep ong dan hi nh

thap:Dt Db Dn D D1 h Bu long

db Z

(mm)

(cai)

100 170 108 205 148 14 16 4

c . Ong hoan lu:

Suat lng hoan lu: Ghl =D.MD.R=5,600 . 41,8 . 2,973=695,864 (Kg/h).Khoi lng rieng cua chat long hoan lu, tra tai lieu

tham khao [4 (tap 1)] tD = 86,5oC va %5,93=Dx : hl = 771,55 (Kg/m3).

Lu lng chat long hoan lu:hl

hl

hl

GQ

= = 0,902 (m3/h).

Chon van toc chat long hoan lu (t chay t bophan tach long ngng tu vao thap): vhl = 0,15 (m/s).

ng knh ong hoan lu: dhl =

046,015,0..3600

902,0.4

..3600

.4==

vhl

Qhl (m).

Suy ra: chon ng knh ong hoan lu: dhl = 0,050 (m).Tai lieu tham khao [4 (tap 2)], chon chieu dai oan

ong noi e ghep mat bch: lhl = 100 (mm).Cac thong so cua bch ghep ong dan hoan lu:

Dt Db Dn D D1 h Bu long

db Z

(mm)

(cai)

50 110 57 140 90 12 12 4

d . Ong dan hi vao ay thap:Suat lng hi vao ay thap: g1 = 391,008 (Kg/h).Khoi lng rieng cua hi vao ay thap c tnh theo

cong thc (xac nh tW = 100oC va yW = 0,018):

( )[ ]( )273.4,22

273.18.1.46

++

=W

WW

dht

yy = 0,605 (Kg/m3).

Lu lng hi ra khoi thap: hd1'

g

Qhd = = 646,722 (m3

/h).

40

157

1149

11501151

1152115311541155

1156

1157115811591160

1161

1162

116311641165

1166

1167116811691170

11711172117311741175

1176

1177

158


41/77


Chon van toc hi vao ay thap: vhd = 25 (m/s).

ng knh ong dan hi: dhd = 096,025..3600

722,646.4

..3600

.4==

hl

hl

v

Q

(m).

Suy ra: chon ng knh ong dan hi: dhd = 0,100 (m).Tai lieu tham khao [4 (tap 2)], chon chieu dai oanong noi e ghep mat bch: lhd = 120 (mm).

Cac thong so cua bch ghep ong dan hi vao aythap:Dt Db Dn D D1 h Bu long

db Z

(mm)

(cai)

100 170 108 205 148 14 16 4

e . Ong dan chat long ay thap:Suat lng chat long vao noi un:G1 =63,608.MG=63,608 .18,189 =1156,973 (Kg/h).

Khoi lng rieng cua chat long chat long vao noiun, tra tai lieu tham khao [4(tap 1)] tW = 100oC vax1=0,0067: L = 898,257 (Kg/m3).

Lu lng chat long vao noi un:L

L

GQ

1'= = 1,288

(m3/h).Chon van toc chat long vao noi un (chat long t

chay vao noi un):vL = 0,2 (m/s).

ng knh ong dan chat long: dL=

2,0..3600

288,1.4

..3600

.4

=

L

L

v

Q=0,048(m).

Suy ra: chon ng knh ong dan: dL = 0,050 (m).Tai lieu tham khao [4 (tap 2)], chon chieu dai oan

ong noi e ghep mat bch: lL = 100 (mm).Cac thong so cua bch ghep ong dan chat long

ay thap:Dt Db Dn D D1 h Bu long

db Z

(mm)

(cai)

50 110 57 140 90 12 12 4

f . Ong dan chat long t noi un (san phamay):

Suat lng san pham ay: GW = W.MW = 42,477 .18,032= 765,939(Kg/h).

Khoi lng rieng cua san pham ay, tra tai lieutham khao [4 (tap 1)]

41

161

1178

1179

1180

11811182118311841185

11861187118811891190

1191

1192

11931194

119511961197

1198

1199120012011202

1203

1204120512061207

12081209

162


42/77


tW= 100oC va xW=0,0011: W = 957,726 (Kg/m3).

Lu lng san pham ay:W

WW

GQ

= = 0,800 (m3/h).

Chon van toc san pham ay (chat long t chay): vW

= 0,12 (m/s).ng knh ong dan san pham ay: dW=

12,0..3600

800,0.4

..3600

.4

=

W

W

v

Q=0,049(m).

Suy ra: chon ng knh ong dan: dW = 0,050 (m).Tai lieu tham khao [4 (tap 2)], chon chieu dai oan

ong noi e ghep mat bch: lW = 100 (mm).Cac thong so cua bch ghep ong dan san pham

ay:Dt Db Dn D D1 h Bu long

db Z

(mm)

(cai)

50 110 57 140 90 12 12 4

5 . Tai treo va chan : Tnh trong lng cua toan thap:

Khoi lng cua mot bch ghep than: (thep X18H10T: X18H10T = 7900 (Kg/m3)).

m1 = ( ) ( ) 7900.02,05,063,0.4

...4

22

1018

22 =

THXt hDD =

18,144(Kg).Khoi lng cua mot mam: (thep X18H10T: X18H10T =

7900 (Kg/m3)).

m2 = THXmmtD 10182

.7,0...4

=4

.0,52.0,0018.0,7.7900

=1,955(Kg).Khoi lng cua than thap:

m3 =4

.(D2ng D2t).Hthan . X18H10T = ( ) 7900.2,14.5,0506,0.

4

22

= 531,808 (Kg).Khoi lng cua ay (nap) thap:

m4 = Say . ay . X18H10T = 0,31 . 0,003 . 7900 = 7,347(Kg).

Khoi lng cua toan thap: m =30.m1+53.m2+m3+2.m4=1193,537(Kg).

Suy ra trong lng cua toan thap: P = m.g = 11708,598(N).

Chan thap:

42

165

1210

1211

1212

12131214

1215

12161217121812191220

1221

12221223

1224

1225

122612271228

1229

12301231

1232

1233

1234123512361237123812391240

1241

166


43/77


Chon chan : thap c tren bon chan. Taitrong cho phep tren mot chan: Gc =

4

598,11708

4=P = 0,293.104 (N).

e am bao o an toan cho thiet b, ta chon: Gc =

0,5.104 (N).

T

ruc

thiet

b

Theo aythiet b

Cac kch thc cua chan : (tnh bang mm)

L B B1 B2 H h s l d

160 110 135 195 240 145 10 55 23

Tai treo:

Chon tai treo: tai treo c gan tren than thap e gicho thap khoi b dao ong trong ieu kien ngoai canh.Ta chon bon tai treo, tai trong cho phep tren mot tai treola Gt = 0,293.104 (N).

e am bao o an toan cho thiet b, ta chon: Gt =0,5.104 (N).

Chon tam lot tai treo khi ghep vao than co kch thcsau:+ Chieu dai tam lot: H = 260 (mm).+ Chieu rong tam lot: B = 140 (mm).

+Be day tam lot la 6 (mm).

43

169

12421243

1244

1245

1246

12471248

1249

1250125112521253125412551256125712581259

1260

170


44/77


Cac kch thc cua tai treo: (tnh bang mm)L B B1 H S l a d

100 75 85 155 6 40 15 18

44

173

12611262

12631264126512661267

174


45/77


CHNG IV: TNH TOAN THIET BTRUYEN NHIET- THIET BPHU.

I . CAC THIET B TRUYEN NHIET:Can bang nhiet lng cho toan thap chng cat:

QF + Q = QW + QD + Qnt + Qm (IV.1)Trong o:

Qnt: nhiet lng ngng tu do hi san pham nhngng tu thanh long. Chon hi san pham nhngng tu hoan toan thanh long.

Qnt = D.(R+1).MD . rD , (KJ/h).Xac nh rD (an nhiet hoa hi cua san pham

nh):Tra tai lieu tham khao [4 (tap 1)], tD = 78,5oC taco:An nhiet hoa hi cua nc: rN = 2346,253 (KJ/kg).An nhiet hoa hi cua ru: rR = 848,084 (KJ/kg).

Suy ra: rD = rR . Dx +(1- Dx ).rN = 848,084.0,935+(1-0,935).2346,253

= 945,465 (KJ/kg).Vay: Qnt =5,600 .(2,973+1) .41,8 .945,465=879211,642 (KJ/h).

QF : nhiet lng do hon hp ru nhap lieu mangvao thap.QF = GF .HF =GF .cF .(tF to ) ,(KJ/h).

Chon nhiet o chuan: to = 20oC.

25,532

205,86

2=

+=

+ oF tt oC , tra tai lieu tham khao [4

(tap 1)], ta co nhiet dung rieng cua ru: cR=2882,25 (J/kg.o).

Suy ra: cF = Fx .cR +(1- Fx ).4186=22,12%.2882,25+(1-22,12%).4186 =

4055,625(J/kg.o).Vay: QF = 1000.4055,625.(86,5-20) = 269699,063(KJ/h).

QW : nhiet lng do san pham ay mang ra tnoi un.

QW = GW .HW =W.MW.cW .(tW to ) ,(KJ/h).Chon nhiet o chuan: to = 20oC.Do san pham ay cha nhieu nc nen nhiet

dung rieng cua san pham ay co the tnh ganung theo cong thc sau:

45

177

1268

1269

1270

1271127212731274127512761277127812791280

128112821283128412851286128712881289

1290129112921293

1294

1295129612971298

1299130013011302130313041305130613071308

178


46/77


cW = (1- Wx ).4186=(1- 0,0029).4186= 4173,861(J/kg.o).Vay: QW = 42,477. 18,032 .4173,861 .(100-20)=255753,898(KJ/h).

QD : nhiet lng do san pham nh mang ra tbo phan tach hoan lu.

QD = GD .HD =D.MD .cD .(tD to ) ,(KJ/h).Chon nhiet o chuan: to = 20oC.

25,492

205,78

2=

+=

+ oD tt oC , tra tai lieu tham khao [4

(tap 1)], ta co nhiet dung rieng cua ru: cR=2830,25 (J/kg.o).

Suy ra: cD = Dx .cR +(1- Dx ).4186=0,935.2882,25+(1-0,935).4186 =

3033,613(J/kg.o).Vay: T (IV.1), ta c:QF = 5,600 .41,8 .3033,613 .(78,5-20) =41537,988

(KJ/h). Qm : nhiet lng ton that ra moi trng xung

quanh.Chon: Qm = 0,05.Q

Vay: nhiet lng can cung cap cho noi un aythap:

Q =95,0

1.(QW + QD + Qnt QF )

=95,0

1(255753,898+41537,988+879211,642-

269699,063)= 954531,016 (KJ/h) = 265,148 (KW).

Chon: + Nhiet o nguyen lieu ban au: tF = 28oC.+ Nhiet o san pham nh sau khi lam nguoi: tD= 35oC.+ Nhiet o san pham ay sau khi trao oi nhiet

vi nguyen lieu ban au: tW = 60oC.

1 . Thiet b ngng tu san pham nh:Chon thiet b ngng tu vo ong loai TH at nam ngang.Ong truyen nhiet c lam bang thep X18H10T, kch

thc ong: 25x2, chieu dai ong la L = 1,5 (m).Chon nc lam lanh i trong ong vi nhiet o au: t1

= 28oC, nhiet o cuoi: t2 = 40oC.Cac tnh chat ly hoc cua nc lam lanh c tra

tai lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh

ttbN =2

21 tt + =34oC:

+ Nhiet dung rieng: cN = 4,181 (KJ/kg.o).

46

181

13091310131113121313131413151316

1317

1318131913201321

132213231324132513261327132813291330

1331

1332

1333133413351336133713381339

13401341134213431344134513461347

1348

1349

182


47/77


+ Khoi lng rieng: N = 994,4 (Kg/m3).+ o nht ong lc: N = 0,7371.10-3 (N.s/m2).+ He so dan nhiet: N = 0,6242 (W/moK).

a . Suat lng nc can dung e ngng tu san

pham nh:GN =

)2840.(181.4.3600

642,879211

).(.3600 12 =

ttcQ

N

nt = 4,868 (Kg/s).

b . Xac nh be mat truyen nhiet :Be mat truyen nhiet c xac nh theo phng trnh

truyen nhiet:

Ftb =log. tK

Qnt

,(m2) (IV.2).

Vi: + K : he so truyen nhiet.+ tlog : nhiet o trung bnh logarit.

Xac nh tlog :Chon kieu truyen nhiet ngc chieu, nen:

229.44

405,78

285,78

)405,78()285,78(log =

=

Ln

t(oK).

Xac nh he so truyen nhiet K:He so truyen nhiet K c tnh theo cong thc:

R

t

N

r

K

11

1

++=

,(W/m2.oK) (IV.3).

Vi: + N : he so cap nhiet cua nc trong ong(W/m2.oK).

+ R : he so cap nhiet cua hi ngng tu(W/m2.oK).

+ rt : nhiet tr cua thanh ong va lp cau.* Xac nh he so cap nhiet cua nc trong ong:

Chon van toc nc i trong ong: vN = 0,4 (m/s).So ong trong mot ng nc:

19~75,0.021,0.

4

.4,994

868,4

..

4

. 22 == NtrNN

vd

G

n (ong).

Chuan so Reynolds :

86,2124710.7371,0

4,994.021,0.75,0.Re

3

. === N

NtrNN

dv

> 104 : che

o chay roi, cong thc xac nh chuan soNusselt co dang:

25,043,08,0 )Pr

Pr.(PrRe..021,0

w

N

NNlNNu =

Trong o:

47

185

1350

1351

13521353

13541355

135613571358

1359

1360

1361

13621363

1364

13651366

1367

13681369

13701371

1372137313741375

1376

1377

1378

13791380

1381

1382

186


48/77


+ l : he so hieu chnh phu thuoc vao ReN vaty le chieu dai ong vi ng knh

ong:ReN=21247,86va 50021,05,1

>=trd

L,nen l =1.

+ PrN : chuan so Prandlt cua nc 34

o

C, nenPrN = 5.+ Prw : chuan so Prandlt cua nc nhiet o

trung bnh cua vach.

Suy ra: 25,0Pr

707,181

w

NNu =

He so cap nhiet cua nc trong ong:

N = 25,025,0Pr

024,5401

021,0.Pr

6242,0.707,181.

NNtr

NN

d

Nu==

Nhiet tai pha nc lam lanh:

)34(Pr

024,5401).(

225,02== w

N

tbNwNN tttq (W/m2) (IV.4).

Vi tw2 : nhiet o cua vach tiep xuc vi nc(trong ong).

* Nhiet tai qua thanh ong va lp cau:

t

ww

tr

ttq

= 21 , (W/m2).

Trong o:+ tw1 : nhiet o cua vach tiep xuc vi ru

(ngoai ong).

+ ct

t

trr +=

Be day thanh ong: t = 2 (mm).He so dan nhiet cua thep khong g: t =

17,5 (W/moK).Nhiet tr trung bnh cua lp ban trong ong

vi nc sach:rc = 1/5000 (m2.oK/W).

Suy ra: rt = 1/3181,818 (m2

.o

K/W).Vay: qt = 3181,818.(tw1-tw2) (IV.5)* He so cap nhiet cua hi ngng tu:

25,0

1

4

1

23

)5,78()..(

...725,0

wngwDR

RRRR

t

A

dtt

r

=

=

at: A= 423

.

...725,0

ngR

RRR

d

r

vi [rR]=[J/kg].

An nhiet ngng tu: rR = rD = 945,465 (KJ/

;kg).Nhiet tai ngoai thanh ong:

48

189

13831384

1385

1386138713881389

1390

1391

1392

1393

1394

139513961397

1398

13991400

1401

1402

1403

14041405140614071408

140914101411

1412

1413

1414

14151416

190


49/77


qR = R.(78,5-tw1) = A.(78,5-tw1)0,75 (IV.6).T (IV.4), (IV.5), (IV.6) ta dung phng phap lap e xac

nh tw1, tw2 :Chon: tw1 = 53,7oC :Cac tnh chat ly hoc cua ru ngng tu c tra tai

lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh ttbD

= 1,662

7,535,78

2

1 =+

=+ wD tt oC:

+ Khoi lng rieng: R = 767,68 (Kg/m3).+ o nht ong lc: R = 0,6018.10-3 (N.s/m2).+ He so dan nhiet: R = 0,2073 (W/moK).

Khi o: A = 3090,099T (IV.6): qR = 3090,099.(78,5-53,7)0,75 = 34340,859

(W/m2).

Xem nhiet tai mat mat la khong ang ke: qt = qR=34340,859 (W/m2).

T (IV.5), ta co: tw2 = tw1-818,3181

tq =42,907oC

Suy ra: ttbw =2

21 ww tt + = 304,482

907,427,53=

+ oC

Tra tai lieu tham khao [4 (tap 1)], Prw = 3,672

T (IV.4): qN = 167,34752)34907,42.(672,3

024,540125,0

= (W/m2).

Kiem tra sai so:

=859,34340

859,34340167,34752 =

R

RN

q

qq=1,2% < 5% :

thoa.Vay: tw1 = 53,7oC va tw2 = 42,907oC.

Khi o: 669,3901672,3

024,540125,0

==N

(W/m2.oC).

712,1384)7,535,78(

099,309025,0

=

=R (W/m2.oC).

T (IV.3):

540,773

712,1384

1

818,3181

1

669,3901

1

1=

++

=K

(W/m2.oC).T (IV.2), be mat truyen nhiet trung bnh:

229,44.540,773.3600

1000.642,879211=tbF = 7,1384 (m2).

Suy ra chieu dai ong truyen nhiet :

L=2,5

2

021,0025,0.19.

1384,7=

+=

(m).

49

193

141714181419142014211422

1423

1424

1425

1426142714281429

14301431

1432

1433

1434

1435

1436

1437

14381439

1440

1441

1442

14431444

1445

1446

1447

194


50/77


So vi L = 1,5(m) th so ng nc la 4~5,1

2,5'=

L

L

(ng nc).Khi o so ong tang len 4 lan: n=19.4 =76 (ong) ~

chon n=91(ong).

* Kiem tra he so cap nhiet cua ru khi co ke ens anh hng cua s sap sep, bo tr ong. Chon cachxep ong thang hang, bo tr theo dang luc giaceu,vay vi 91 ong th ta sep c 9 hang.

So ong trung bnh trong 1 hang: 11,109

91= , tra tai lieu

tham khao II, ta co tb = 0,58.Khi o: R = 0,58.1384,712 = 803,133 (W/m2.oC).Tnh lai he so truyen nhiet K t CT(IV.3), ta co: K =

550,749 (W/m2.oC).

Suy ra: be mat trung bnh: 026,10229,44.749,550.3600

1000.642,879211==tbF

(m2).Khi o: chieu dai ong truyen nhiet:

L=).(403,1

2

021,0025,0.91.

026,10m=

+

< 1,5(m) : thoa.

Vay : Thiet b ngng tu san pham nh la thiet btruyen nhiet vo ong gom n=91(ong), dai L=1,5(m).

Ong c bo tr theo hnh luc giac eu. Nen ta coso ong tren ng cheo hnh luc giac: b = 9(ong). Chonbc ngang gia hai ong: t = 1,4.dng = 1,4.0,025 = 0,035 (m).

ng knh vo thiet b: Dv = t.(b-1)+4.dng = 0,035(9-1)+4.0,025

= 0,380(m).2 . Thiet b lam nguoi san pham nh:

Chon thiet b lam nguoi san pham nh la thiet btruyen nhiet ong long ong. Ong truyen nhiet c lambang thep X18H10T, kch thc ong trong: 16x1,6 ; kch

thc ong ngoai: 25x2,5.Chon: + Nc lam lanh i trong ong 16x1,6 (ong trong)vi nhiet o au: t1 = 28oC, nhiet o cuoi: t2 = 40oC.

+ San pham nh i trong ong 25x2,5 (ong ngoai)vi nhiet o au:tD = 78,5oC, nhiet o cuoi: tD = 35oC.

Cac tnh chat ly hoc cua nc lam lanh c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh

ttbN =2

21 tt + =34oC:

+ Nhiet dung rieng: cN = 4,181 (KJ/kg.o).

+ Khoi lng rieng: N = 994,4 (Kg/m3).

50

197

1448

144914501451

1452145314541455

1456

1457

145814591460

1461

14621463

1464

14651466146714681469147014711472

1473147414751476

1477147814791480148114821483

1484

1485

1486

198


51/77


+ o nht ong lc: N = 0,7371.10-3 (N.s/m2).+ He so dan nhiet: N = 0,6242 (W/moK).

Cac tnh chat ly hoc cua san pham nh c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh

ttbD = 75,562 355,782'

=+=+ DDtt

oC:+ Nhiet dung rieng: cD= 3014,63 (J/kg.o).+ Khoi lng rieng: D = 775,95 (Kg/m3).+ o nht ong lc: D = 0,6988.10-3 (N.s/m2).+ He so dan nhiet: D = 0,2029 (W/moK).

a . Suat lng nc can dung e lam mat sanpham nh:

Suat lng san pham nh:GD = D.MD = 5,600.41,8 = 234,08 (Kg/h) = 0,065 (Kg/s).

Lng nhiet can tai:Qt = GD.cD.(tD-tD) = 0,065.3014,63.(78,5-35) =8526(J/s)

=8,526(KJ/s).Suat lng nc can dung:

GN =)2840.(181.4

526,8

).( 12 =

ttcQ

N

D = 0,170 (Kg/s).


truyen nhiet:

Ftb = log. tKQ

t

,(m2) (IV.7).Vi: + K : he so truyen nhiet.

+ tlog : nhiet o trung bnh logarit. Xac nh tlog :

Chon kieu truyen nhiet ngc chieu, nen:

478,18

2835

405,78

)2835()405,78(log =

=

Ln

t(oK).

Xac nh he so truyen nhiet K:

He so truyen nhiet K c tnh theo cong thc:

D

t

N

r

K

11

1

++=

,(W/m2.oK) (IV.8).

Vi: + N : he so cap nhiet cua nc trong ong(W/m2.oK).

+ D : he so cap nhiet cua san pham nh(W/m2.oK).

+ rt : nhiet tr cua thanh ong va lp cau.

* Xac nh he so cap nhiet cua san pham nh ong ngoai:

51

201

1487

148814891490

1491

1492

1493

1494

14951496149714981499

1500150115021503

1504

150515061507

1508

1509

1510

15111512

1513

1514

1515

1516

15171518

15191520

152115221523

202


52/77


Van toc cua san pham nh i trong ong ngoai:

741,0)016,002,0.(

4.

95,775

065,0

)..(

4.

2222=

=

=

ngtrD

DD

dD

Gv (m/s).

ng knh tng ng: dtd = Dtr dng = 0,02- 0,016 =

0,004 (m).Chuan so Reynolds :

24,329110.6988,0

95,775.004,0.651,0.Re

3

. === D

DtdDD

dv

> 2320 : che

o qua o, cong thc xac nh chuan so Nusseltco dang:

25,0

1

43,0)

Pr

Pr.(Pr..

w

D

DlD CNu =

Trong o:

+ l : he so hieu chnh phu thuoc ty le chieudai ong vi ng knh ong1, chon l =1.+ C : he so phu thuoc vao chuan so Reynolds,

ReD = 3291,24 nenC = 7,252.

+ PrD : chuan so Prandlt cua san pham nh

56,75oC, nen2029,0

63,3014.10.6988,0.Pr

3

==D

DDD

c

=

10,383.+ Prw1 : chuan so Prandlt cua san pham nh

nhiet o trung bnh cua vach.Suy ra: 25,0

1Pr

610,35

w

DNu =

He so cap nhiet cua san pham nh trong ongngoai:

D = 25,01

25,0

1 Pr

339,1806

004,0.Pr

2029,0.610,35.

wwtd

DD

d

Nu==

Nhiet tai pha san pham nh:

)75,56(Pr

339,1806

).( 125,01

1 ww

wtbDDD tttq == (W/m2

) (IV.9).Vi tw1 : nhiet o cua vach tiep xuc vi san

pham nh (ngoai ong nho).* Nhiet tai qua thanh ong va lp cau:

t

ww

tr

ttq

= 21 , (W/m2).

Trong o:+ tw2 : nhiet o cua vach tiep xuc vi nc

(trong ong nho).

52

205

1524

1525

1526

15271528

1529

15301531

1532

1533

153415351536153715381539

1540

15411542

1543

1544

15451546

1547

1548

1549155015511552

1553

155415551556

206


53/77


+ 21 rrrt

t

t ++=

Be day thanh ong: t = 1,6 (mm).He so dan nhiet cua thep khong g: t = 17,5

(W/mo

K). Nhiet tr trung bnh cua lp ban trong ong vinc sach:

r1 = 1/5000 (m2.oK/W).Nhiet tr lp cau pha san pham nh: r2 =

1/5000 (m2.oK/W).Suy ra: rt = 1/2034,884 (m2.oK/W).

Vay: qt = 2034,884.(tw1-tw2) (IV.10).* Xac nh he so cap nhiet cua nc trong ong

nho:

Van toc nc i trong ong:329,1

0128,0.

4.

4,994

170,0

.

4.

22===

trN

NN

d

Gv (m/s).

Chuan so Reynolds :

04,2294110.7371,0

4,994.0128,0.329,1.Re

3

. === N

NtrN

N

dv

> 104 : che

o chay roi, cong thc xac nh chuan so Nusseltco dang:

25,0

2

43,08,0)

Pr

Pr.(PrRe..021,0

w

NNNlNNu =

Trong o:+ l : he so hieu chnh phu thuoc vao ReN va

ty le chieu dai ong vi ng knhong:ReN=22941,04,chon l =1.

+ PrN : chuan so Prandlt cua nc 34oC, nenPrN = 5.

+ Prw2 : chuan so Prandlt cua nc nhiet otrung bnh cua vach.

Suy ra: 25,02Pr

204,193

w

NNu =

He so cap nhiet cua nc trong ong:

N = 25,02

25,0

2 Pr

714,9421

0128,0.Pr

6242,0.204,193.

wwtr

NN

d

Nu==

Nhiet tai pha nc lam lanh:

)34(Pr

714,9421).( 225,0

2

2 == ww

tbNwNN tttq (W/m2) (IV.11).

Chon: tw1 = 42,65oC :

53

209

1557

1558

1559

156015611562156315641565

1566156715681569

1570

1571

1572

1573

15741575

1576

1577

15781579

15801581158215831584

1585

1586

1587

1588

1589

1590

210


54/77


Cac tnh chat ly hoc cua san pham nh c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet otw1=42,65oC:

+ Nhiet dung rieng: cR= 2841,64 (J/kg.o).+ o nht ong lc: R = 0,9049.10-3 (N.s/m2).+ He so dan nhiet: R = 0,1966 (W/moK).

Khi o xem:Prw1 ~ 081,131966,0

64,2841.10.9049,0. 3==

R

RR c

T (IV.9): qD = 391,13392)65,4275,56.(081,13

339,180625,0

= (W/m2).

Xem nhiet tai mat mat la khong ang ke: qt = qD=13392,391 (W/m2).

T (IV.10), ta co: tw2 = tw1-884,2034

tq =36,069oC

Suy ra: ttbw =2

21 ww tt + = 360,392

069,3665,42 =+ oC

Tra tai lieu tham khao [4 (tap 1)], Prw2 = 4,386

T (IV.11): qN = 483,13470)34069,36.(386,4

714,942125,0

= (W/m2).

Kiem tra sai so:

=391,13392

391,13392483,13470 =

D

DN

q

qq=0,58% < 5% :


Khi o: 625,6510386,4

714,942125,0

==N

(W/m2.oC).

815,949081,13

339,180625,0

==D

(W/m2.oC).

T (IV.8):977,588

815,949

1

884,2034

1

625,6510

1

1=

++=K

(W/m2.oC).T (IV.7), be mat truyen nhiet trung bnh:

478,18.977,588

1000.526,8

=tbF = 0,7834 (m2

).Suy ra chieu dai ong truyen nhiet :

L317,17

2

0128,0016,0.

7834,0=

+=

(m).

Chon: L = 20(m),(d tr khoang 15%).

Kiem tra: 505,15620128,0

20>==

trd

Lth l = 1: thoa.

Vay: thiet b lam mat san pham nh la thiet btruyen nhiet ong long ong vi chieu dai ong

54

213

1591159215931594

1595

1596

1597

1598

15991600

1601

1602

1603

1604

1605

1606

16071608

1609

1610

1611

16121613

16141615

1616

1617

1618

16191620

214


55/77


truyen nhiet L = 20(m), chia thanh 10 day, moi daydai 2 (m).

3 . Noi un gia nhiet san pham ay:Chon noi un gia nhiet san pham ay la noi un

Kettle, ong truyen nhiet c lam bang thep X18H10T,kch thc ong 25x2.Chon hi ot la hi nc 2 at, i trong ong 25x2. Tra tai

lieu tham khao [4(tap1)], ta co:+ Nhiet o soi: tsN = 119,6oC.+ An nhiet ngng tu: rN = 2208 (KJ/kg).

San pham ay trc khi vao noi un co nhiet o lat1 = 99oC (do x1=0,0067 ), nhiet o ra la tW = 100oC.a . Suat lng hi nc can dung :

Lng nhiet can tai cung cap cho ay thap: Q =

265,148 (KW).Suat lng hi nc can dung:

GhN =2208

148,265d =Nr

Q= 0,120 (Kg/s).


truyen nhiet:

Ftb =log. tK

Qd

,(m2) (IV.12).

Vi: + K : he so truyen nhiet.+ tlog : nhiet o trung bnh logarit.

Xac nh tlog :Chon kieu truyen nhiet ngc chieu, nen:

096,20

1006,119

996,119

)1006,119()996,119(log =

=

Ln

t(oK).

Xac nh he so truyen nhiet K:He so truyen nhiet K c tnh theo cong thc:

D

t

N

r

K

11

1

++

=

,(W/m2

.o

K) (IV.13).

Vi: + N : he so cap nhiet cua hi nc(W/m2.oK).

+ D : he so cap nhiet cua san pham ay(W/m2.oK).

+ rt : nhiet tr cua thanh ong va lp cau.* Xac nh he so cap nhiet cua hi nc:

He so cap nhiet cua hi nc c xac nh theocong thc:

55

217

16211622

162316241625162616271628162916301631163216331634

16351636

1637

163816391640

1641

1642

1643

16441645

1646

16471648

1649

16501651

16521653

1654165516561657

218


56/77


N =25,0

1

25,0

1 021,0).6,119(

1000.2208..725,0

).(..725,0

=

wtrwsNN

tA

dtt

rA

= 25,01 )6,119(

.415,73

wt

A

Vi: + tw1 : nhiet o cua vach tiep xuc vi hinc(trong ong).

+ A : he so phu thuoc vao tnh chat vat lync theo nhiet o, c tra tai lieu thamkhao [2].

Nhiet tai pha hi: 75,011 )6,119.(.415,73).( wwsNNN tAttq == (W/m2)

(IV.14).* Nhiet tai qua thanh ong va lp cau:

t

ww

tr

ttq

=

21

, (W/m2).Trong o:

+ tw2 : nhiet o cua vach tiep xuc vi sanpham ay (ngoai ong).

+ 21 rrrt

t

t ++=

Be day thanh ong: t = 2 (mm).He so dan nhiet cua thep khong g: t =

17,5 (W/moK).Nhiet tr trung bnh cua lp ban trong ong

vi nc sach: r1 = 1/5000 (m2.oK/W).Nhiet tr lp cau pha san pham ay: r2

=1/500(m2.oK/W).Suy ra: rt = 1/1944,444 (m2.oK/W).

Vay: qt = 1944,444.(tw1-tw2) (IV.15).* Xac nh he so cap nhiet cua san pham ay:

He so cap nhiet cua san pham ay c xacnh theo cong thc (che o soi sui bot va xem

san pham ay nh la nc): D =

3600

8,4186.39.p0,5.(tw2 100)2,33

Vi: + p: ap suat e at nhiet o soi cuasan pham ay, khi o

p = 1 at = 105 (N/m2).Suy ra: D = 14343,143(tw2 100)2,33

Nhiet tai pha san pham ay:33,3

22 )100(143,14343)100.( == wwDD ttq (W/m2)(IV.16).

Chon: tw1 = 116,655o

C :

56

221

1658

1659

166016611662166316641665

1666

16671668

1669

167016711672

1673

1674

16751676

1677167816791680

168116821683168416851686

1687

168816891690

16911692

1693

1694

1695

222


57/77


Khi o, nhiet o trung bnh2

655,1166,119 +=

118,128oC ta tra cA = 187,1574

T (IV.14): qN =73,415.187,1574.(119,6-116,655)0,75

= 30889,133(W/m2).Xem nhiet tai mat mat la khong ang ke: qt =

qN =30889,133 (W/m2).

T (IV.15), ta co: tw2 = tw1-444,1944

tq =100,769oC

T (IV.16): qD =14343,143.(100,769-100)3,33=31708,196(W/m2).

Kiem tra sai so:

=133,30889

196,31708133,30889 =

D

DN

q

qq=2,65% < 5% :


Khi o: 670,10488)655,1166,119(

1574,187.415,7325,0

=

=N (W/m2.oC).

758,24986)100769,100.(143,14343 33,3 ==D (W/m2.oC).

T (IV.13):295,1539

758,24986

1

444,1944

1

670,10488

1

1=

++=K

(W/m2.oC).

T (IV.12), be mat truyen nhiet trung bnh:096,20.295,1539

1000.148,265=tbF = 8,572 (m2).

Chon so ong truyen nhiet: n = 91 (ong).Chieu dai ong truyen nhiet:

L304,1

2

021,0025,0.91.

572,8=

+=

(m).

Chon: L = 1,5(m),(d tr khoang 10%).Vay: noi un gia nhiet san pham ay la thiet b

truyen nhiet vo - ong vi so ong n = 91, chieu daiong truyen nhiet L = 1,5(m).Ong c bo tr theo hnh luc giac eu. Nen ta co

so ong tren ng cheo hnh luc giac: b = 9(ong).Chon bc ngang gia hai ong: t = 1,4.dng = 1,4.0,025 =0,035 (m).

ng knh vo thiet b: Dv = t.(b-1)+4.dng = 0,035(9-1)+4.0,025

= 0,380(m).4 . Thiet b trao oi nhiet gia nhap lieu

va san pham ay:

57

225

1696

169716981699

170017011702

1703

170417051706

1707

17081709

1710

1711

1712

1713

17141715

17161717

1718

17191720

172117221723172417251726172717281729

1730

1731

226


58/77


Chon thiet b thiet b trao oi nhiet gia nhap lieuva san pham ay la thiet b truyen nhiet ong longong. Ong truyen nhiet c lam bang thep X18H10T,kch thc ong trong: 25x2 ; kch thc ong ngoai: 38x2.

Dong nhap lieu i trong ong 25x2 (ong trong) vi nhieto au: tF = 28oC.

San pham ay i trong ong 38x2 (ong ngoai)vi nhieto au: tW = 100oC, nhiet o cuoi: tW = 60oC.

Cac tnh chat ly hoc cua san pham ay c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh

ttbW =2

' WW tt + =80oC:

+ Nhiet dung rieng: cW = 4,195 (KJ/kg.o).+ Khoi lng rieng: W = 971,8 (Kg/m3).

+ o nht ong lc: W = 0,355.10-3

(N.s/m2

).+ He so dan nhiet: W = 0,675 (W/moK).a . Nhiet o dong nhap lieu sau khi trao oi

nhiet vi san pham ay:Suat lng san pham ay:

GW = W.MW = 42,477.18,032 = 765,939 (Kg/h).Lng nhiet can tai:

Qt =3600

WG .cW.(tW-tW) =3600

939,765.4,195.(100-

60)=35,701(KW).

28oC, ta xem nhiet dung rieng cua san pham nhla hang so, hay nhiet dung rieng cua ru cR = 2,595(KJ/kg.o).

Suy ra: cF = cR . Fx +(1- Fx ).4,18 = 2,595.0,2212+(1-0,2212).4,18

= 3,829 (KJ/kg.o).Nhiet o san pham nh sau khi trao oi nhiet vi

san pham ay:

tF =28

3600

1000

.829,3

701,35'

.+=+ F

FF

t tGc

Q

= 61,566oC.

Cac tnh chat ly hoc cua san pham nh c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet otrung bnh ttbF =

,442

28566,61

2

'"=

+=

+DD

tt

oC:+ Khoi lng rieng: F = 954,37 (Kg/m3).+ o nht ong lc: F = 1,06.10-3 (N.s/m2).

58

229

1732173317341735173617371738173917401741

1742

1743

1744

1745174617471748174917501751

1752

1753

17541755175617571758175917601761

1762

176317641765

1766

1767

1768

1769

230


59/77


+ He so dan nhiet: F = 0,5184 (W/moK).b . Xac nh be mat truyen nhiet :

Be mat truyen nhiet c xac nh theo phng trnhtruyen nhiet:

Ftb = log. tKQ

t

,(m2) (IV.17).Vi: + K : he so truyen nhiet.

+ tlog : nhiet o trung bnh logarit. Xac nh tlog :

Chon kieu truyen nhiet ngc chieu, nen:

119,35

2860

566,61100

)2860()566,61100(log =

=

Ln

t(oK).

Xac nh he so truyen nhiet K:

He so truyen nhiet K c tnh theo cong thc:

W

t

F

r

K

11

1

++=

,(W/m2.oK) (IV.18).

Vi: + F : he so cap nhiet cua dong nhap lieu(W/m2.oK).

+ W : he so cap nhiet cua san pham ay(W/m2.oK).

+ rt : nhiet tr cua thanh ong va lp cau.

* Xac nh he so cap nhiet cua dong nhap lieu ong trong:Van toc dong nhap lieu i trong ong:

84,0021,0.

4.

37,954.3600

1000

.

4.

.3600 22===

trF

FF

d

Gv (m/s).

Chuan so Reynolds :

48,1588810.06,1

37,954.021,0.84,0.Re

3===

F

FtrFF

dv

> 104 : che

o chay roi, cong thc xac nh chuan so Nusseltco dang:

25,0

2

43,08,0)

Pr

Pr.(PrRe..021,0

w

FFFlFNu =

Trong o:+ l : he so hieu chnh phu thuoc vao ReF va

ty le chieu dai ong vi ng knhong:ReF=15888,48,chon l =1.

+ PrF : chuan so Prandlt cua dong nhap lieu 44,783oC, nen

PrF = 5184,03829.10.06,1. 3

=FFF c

= 7,829.

59

233

1770177117721773

1774

1775

1776

17771778

1779

1780

1781

1782

17831784

17851786

1787178817891790

1791

1792

1793

17941795

1796

1797

17981799

180018011802

1803

234


60/77


+ Prw2 : chuan so Prandlt cua dong nhap lieu nhiet o trung bnh cua vach.

Suy ra: 25,02Pr

346,195

w

FNu =

He so cap nhiet cua dong nhap

Documents

Ccat Acid Acetic-Nuoc(Mam Xuyen Lo)