ĐỒ Án

B CNG THNG

TRNG HCN TP.H CH MINH

CNG HA X HI CH NGHA VIT NAM

c lp T do Hnh phc

__________________

NHIM V N HC PHN

KHOA: CNG NGH HO HC

B MN: MY & THIT B

H V TN: V TRNG QUN MSSV:11254511 LP: DHHD7

1. Tn n:

Thit k thp mm chp chng luyn tch hn hp Etanol Nc

2. Nhim v n (yu cu v ni dung v s liu ban u)

2.1 S liu ban u: Lu lng hn hp u vo thp (kg/h): F = 1800 kg/h

Nng hn hp u (phn khi lng): = 33,5%

Nng sn phm nh (phn khi lng): = 90%

Nng sn phm y (phn khi lng): = 3 %

2.2 Yu cu v ni dung:

Quy trnh cng ngh

Cn bng vt cht v cn bng nng lng

Tnh ton thit b chnh v thit b ph

Tnh c kh

Bng v: quy trnh cng ngh v thit b chnh (A1)

3. Ngy giao nhim v n: ........................................................24/05/2014

4. Ngy hon thnh nhim v: .......................................................10/07/2014

5. H v tn ngi hng dn: Cao Thanh Nhn

Tp.H Ch Minh, ngy 24 thng 05 nm 2014

T TRNG B MN GIO VIN HNG DN (K v ghi r h tn) (K v ghi r h tn)

Trn Hoi c Cao Thanh Nhn

SVTH: V Trng Qun MSSV: 11254511 Lp: HHD7 GVHD: Cao Thanh Nhn

N HC PHN CNG NGH HA HC

LI M U

Cng ngh ha hc l mt trong nhng ngnh ng gp rt ln trong s pht

trin ca nn cng nghip nc ta. Trong ngnh sn xut ha cht cng nh s

dng sn phm ha hc, nhu cu s dng nguyn liu c tinh khit cao phi ph

hp vi qui trnh sn xut hoc nhu cu s dng.

Ngy nay, cc phng php c s dng nng cao tinh khit l: chng

ct, trch ly, c c, hp thu Ty theo c tnh sn phm m ta la chn phng

php thch hp. H Ethanol nc l 2 cu t tan ln hon ton, ta dng phng

php chng ct nng cao tinh khit cho Ethanol.

n mn hc Qu trnh v Thit b l mt mn hc mang tnh tng hp trong

qu trnh hc tp ca cc k s ho tng lai. Mn hc gip sinh vin gii quyt

nhim v tnh ton c th v: yu cu cng ngh, kt cu, gi thnh ca mt thit b

trong sn xut ho cht - thc phm. y l bc u tin sinh vin vn dng

nhng kin thc hc ca nhiu mn hc vo gii quyt nhng vn k thut

thc t mt cch tng hp.

Em chn thnh cm n Thy Cao Thanh Nhn v cc Qu Thy C b mn

My & Thit B gip em hon thnh n ny. Tuy nhin, trong qu trnh hon

thnh n vn khng trnh khi c sai st, em rt mong qu thy c gp , ch dn.

Em xin cm n Qu Thy C!



NHN XT CA GIO VIN HNG DN

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

Phn nh gi:

thc thc hin: ....................................................................................

Ni dung thc hin: ................................................................................

Hnh thc trnh by: ................................................................................

Tng hp kt qu: ..................................................................................

im bng s: ...................... im bng ch: ..................................

Tp. H Ch Minh, ngy ..... thng ..... nm 2014

Gio vin hng dn



NHN XT CA GIO VIN PHN BIN

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

....................................................................................................................

Phn nh gi:

thc thc hin: ....................................................................................

Ni dung thc hin: ................................................................................

Hnh thc trnh by: ................................................................................

Tng hp kt qu: ..................................................................................

im bng s: ...................... im bng ch: ..................................

Tp. H Ch Minh, ngy ..... thng ..... nm 2014 Gio vin phn bin



MC LC PHN 1: M U ....................................................................................... 1

I.L thuyt v chng luyn ........................................................................ 1

II.u, khuyt im ca phng php chng a chp: ............................ 2

III.Dy chuyn cng ngh: ........................ Error! Bookmark not defined.

PHN 2: TNH CNG NGH ...................................................................... 8

Chng 1: TNH S A .......................................................................... 9

1.1. Tnh lng hn hp: ....................................................................... 9

1.2 Xc nh s a ca thp ............................................................... 10

Chng 2: TNH NG KNH THIT B ............................................ 16

2.1. ng knh on luyn: ............................................................... 16

2.2. ng knh on chng: ............................................................. 20

Chng 3: CN BNG NHIT LNG ................................................ 24

3.1. Cn bng nhit lng ca thit b un nng hn hp u: .......... 24

3.2. Cn bng nhit lng ca thp chng luyn: .............................. 26

3.3. Cn bng nhit lng ca thit b ngng tu hi lu: .................... 28

3.4. Cn bng nhit lng ca thit b lm lnh: ................................ 28

Chng 4: TNH KT CU CA THP CHNG LUYN ..................... 30

4.1. Kt cu da phn luyn: ................................................................ 30

4.2. Kt cu a on chng : ............................................................. 33

PHN 3: TNH C KH THIT B CHNH ................................................. 37

I. Tnh thn thit b chnh: ....................................................................... 37

II. Tnh y v np thit b: ..................................................................... 40

III. Tnh b dy lp cch nhit: ............................................................... 40

IV. Tnh ng knh cc loi ng dn: ................................................... 42

V. Chn bch: .......................................................................................... 44

VI. Tnh ti trng ca thp: ..................................................................... 46

VII. Chn tai treo, chn : ..................................................................... 49

PHN 4: TNH THIT B PH ................................................................ 51

I. Tnh ton thit b ngng t hi lu: ..................................................... 51

II. Thit b gia nhit nhp liu: ................................................................. 55



III. Ni un: ............................................................................................. 57

IV. Thit b lm lnh sn phm nh: ...................................................... 60

V. Tnh v chn bm: ............................................................................. 63

PHN 5: KT LUN .................................................................................. 68

Cc ti liu tham kho : ......................................................................... 68


N HC PHN CNG NGH HA HC Trang 1

PHN 1: M U

I. L thuyt v chng luyn.

Chng l phng php dng tch cc hn hp cht lng cng nh cc hn

hp kh lng thnh cc cu t ring bit da vo bay hi khc nhau ca cc cu

t trong hn hp, ngha l khi cng mt nhit th p sut hi ca cc cu t

khc nhau.

Khi chng ta thu c nhiu sn phm v thng bao nhiu cu t s c by

nhiu sn phm. i vi trng hp hn hp chng ch gm hai cu t th sn phm

nh gm cu t c bay hi ln v mt phn rt t cu t c bay hi b cn

sn phm y gm cu t c bay hi b v mt phn rt t cu t c bay hi

ln.

Trong sn xut c rt nhiu phng php chng nh chng n gin, chng

bng hi nc trc tip, chng chn khng v chng luyn. Ty thuc vo iu kin

sn c, tnh cht hn hp, yu cu v tinh khit sn phm m ta chn phng

php chng cho thch hp.

- Chng n gin dng tch cc hn hp gm cc cu t c bay hi rt

khc nhau. Phng php ny thng dng tch s b v lm sch cu t khi

tp cht.

- Chng bng hi nc trc tip dng tch cc hn hp gm cc cht kh bay

hi v tp cht khng bay hi, thng dng trong trng hp cht c tch khng

tan vo nc

- Chng chn khng dng trong trng hp cn h thp nhit si cu t. V

d nh trng hp cc cu t trong hn hp d b phn hy nhit cao hay

trng hp cc cu t c nhit si qu cao.

- Chng luyn l phng php ph bin nht tch hon ton hn hp cc

cu t d bay hi c tnh cht ha tan mt phn hoc ha tan hon ton vo nhau.

- Chng luyn p sut thp dng cho cc hn hp d b phn hy nhit

cao v hn hp c nhit si cao.

- Chng luyn p sut cao dng cho cc hn hp khng ha lng p sut

thng.



- Chng luyn p sut thng (p sut kh quyn ) dng cho hn hp khng

thuc cc trng hp trn.

Ngi ta tin hnh chng luyn hn hp cn chng trong thp chng luyn,

thp gm nhiu a, trn mi a xy ra qu trnh chuyn khi gia pha lng v pha

hi. Hi i t di ln qua cc l ca a, lng i t trn xung theo cc ng chy

chuyn, nng cc cu t v nhit si mi a thay i theo chiu cao ca

thp. Do mt phn cu t d bay hi chuyn t pha lng vo pha hi v mt

phn t hn chuyn t pha hi vo pha lng, lp li nhiu ln bc hi v ngng t

nh th, hay ni mt cch khc, vi mt s a tng ng, cui cng trn nh

thp ta thu c cu t d bay hi dng nguyn cht v thp ta thu c cu t

kh bay hi dng nguyn cht.

Qu trnh chng luyn c thc hin trong thit b loi thp lm vic lin tc

hoc gin on.

y ta s thit k h thng chng luyn thp mm chp lm vic lin tc vi

hn hp chng l ru mtylic v nc. Khi chng luyn lin tc, hn hp u c

a vo thp a tip liu (nm phn gia thn thp) mt cch lin tc, sn

phm nh v sn phm y cng c ly ra lin tc.

II. u, khuyt im ca phng php chng a chp.

u im: Tch c sn phm c tinh khit cao, d khng ch qu trnh, b

mt tip xc pha tng i ln, tr lc khng cao.

Khuyt im: Tip xc pha khng lin tc, cu to phc tp.

II.1. Tnh cht l ha ca ru tylic.

Ethanol c cng thc phn t: CH3-CH2-OH, khi lng phn t: 46 vC

L cht lng c mi c trng, khng c, tan nhiu trong nc

Mt s thng s vt l v nhit ng ca Ethanol

+ Nhit si 760 (mmHg): 78.3oC.

+ Khi lng ring: d420 = 810 (Kg/m3)

Tnh cht ha hc

Tt c cc phn ng ho hc xy ra nhm hydroxyl (-OH) ca Ethanol l th

hin tnh cht ho hc ca n

Phn ng ca hydro trong nhm hydroxyl



CH3-CH2-OH CH3-CH2-O- + H+

Hng s phn ly ca Ethanol: , cho nn Ethanol l cht trung

tnh.

Tnh acid ca ru th hin qua phn ng vi kim loi kim, Natri hydrua

(NaH), Natri amid(NaNH2):

CH3-CH2-OH + NaH CH3-CH2-ONa + H2

Natri etylat

Do : tnh acid ca ru nh hn tnh acid ca nc,

nn khi mui Natri etylat tan trong nc s b thu phn thnh ru tr li.

Tc dng vi acid to ester: Ethanol c tnh baz tng ng vi nc. Khi

ru tc dng vi acid v c H2SO4, HNO3 v acid hu c u to ra ester.

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

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

Phn ng trn nhm hydroxyl:

Tc dng vi HX: CH3-CH2-OH + HX CH3-CH2-X + H2O

Tc dng vi Triclo Pht pho

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

Tc dng vi NH3: CH3-CH2-OH + NH3 C2H5-NH2 + H2O

Phn ng to eter v tch loi nc

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

CH3-CH2-OH CH2=CH2 + H2O

Phn ng hydro v oxy ho

CH3-CH2-OH CH3-CHO + H2

ng dng ca Ethanol c nhiu ng dng hn Methanol, n ng mt vai tr

quan trng trong nn kinh t quc dn. N l nguyn liu dng sn sut hn 150

181023

OHCHCHK

1410223

OHOHCHCH KK

Lnh

Al2O3

to

H2SO4

>150oC

H2SO4

>150oC

Cu 200-300

oC



mt hng khc nhau v c ng dng rng ri trong cc ngnh: cng nghip nng,

y t v dc, quc phng, giao thng vn ti, dt, ch bin g v nng nghip.

S tm tt v tr ca Ethanol trong cc ngnh cng nghip

Phng php iu ch: c nhiu phng php iu ch Ethanol: hydrat ho

etylen vi xc tc H2SO4; thu phn dn xut halogen v ester ca Ethanol khi un

nng vi nc xc tc dung dch baz; hydro ha aldyhyt acetic; t cc hp cht c

kim

Trong cng nghip, iu ch Ethanol bng phng php ln men t ngun tinh

bt v r ng. Nhng nm gn y, nc ta cng ngh sn sut Ethanol ch

yu l s dng chng nm men Saccharomyses cerevisiae ln men tinh bt.

C6H6O6 2C2H5OH + 2CO2 + 28 Kcal

95% nguyn liu chuyn thnh Ethanol v CO2.

5% nguyn liu chuyn thnh sn phm ph: glyxrin, acid sucxinic, du fusel,

metylic v cc acid hu c (lactic, butylic).

II.2. Nc.

Trong iu kin bnh thng: nc l cht lng khng mu, khng mi, khng

v nhng khi nc dy s c mu xanh nht.

Khi ha rn n c th tn ti dng 5 dng tinh th khc nhau:

Nm men Zymaza



Khi lng phn t: 18 g/mol

Khi lng ring d4oC: 1 g/mol

Nhit nng chy: 0oC

Nhit si: 100oC

Nc l hp cht chim phn ln trn tri t (3/4 din tch tri t l nc

bin) v rt cn thit cho s sng. Nc l dung mi phn cc mnh, c kh nng

ho tan nhiu cht v l dung mi rt quan trng trong k thut ha hc.

II.3. Hn hp Ethanol Nc.

Bng 1: Thnh phn lng ( x ) hi (y) v nhit si ca hn hp Ethanol -

Nc 760 mmHg.

x(%phn

mol)

0 5 10 20 30 40 50 60 70 80 90

Y

(%phn

mol)

0 33,2 44,2 53,1 57,6 61,4 65,4 69,9 75,3 81,8 89,8

t(oC) 100 90,5 86,5 83,2 81,7 80,8 80 79,4 79 78,6 78,4

Hnh 1: Thnh phn lng ( x ) hi (y) v nhit si ca hn hp Ethanol -

Nc 760 mmHg.



III. Quy trnh cng ngh.

Ethanol l mt cht lng tan v hn trong H2O, nhit si l 78,3oC

760mmHg, nhit si ca nc l 100oC 760mmHg: hi cch bit kh xa nn

phng php hiu qu thu Ethanol c tinh khit cao l phng php chng

ct.

Trong trng hp ny, ta khng th s dng phng php c c v cc cu

t u c kh nng bay hi, v khng s dng phng php trch ly cng nh

phng php hp th do phi a vo mt khoa mi tch, c th lm cho qu

trnh phc tp hn hay qu trnh tch khng c hon ton.

Hnh 2: S qui trnh cng ngh chng ct h Ethanol Nc

Ch thch cc k hiu trong qui trnh:

1. Bn cha nguyn liu.

2. Bm.

3. Bn cao v.

4. ng tun hon.

5. Lu lng k.

6. Thit b gia nhit nhp liu.

7. Thp chng ct.



8. Ni un.

9. Thit b ngng t.

10 . Thit b phn tch hi lu.

11. Thit b lm lnh.

12. Bn cha sn phm nh.

13. Bn cha sn phm y.

14. By hi.

Thuyt minh qui trnh cng ngh:

Hn hp Ethanol nc c nng Ethanol 10% ( theo phn khi lng ),

nhit khong 28oC ti bnh cha nguyn liu (1) c bm (2) bm ln bn cao

v (3). T c a n thit b un si dng nhp liu (6). Sau , hn hp

c un si n nhit si v c a vo thp chng ct (7) a nhp liu.

Trn a nhp liu, cht lng c trn vi phn lng t on ct ca thp chy

xung. Trong thp, hi i t di ln gp cht lng t trn xung. y, c s tip

xc v trao i gia hai pha vi nhau. Pha lng chuyn ng trong phn chng cng

xung di cng gim nng cc cu t d bay hi v b pha hi to nn t ni

un (10) li cun cu t d bay hi. Nhit cng ln trn cng thp, nn khi hi i

qua cc a t di ln th cu t c nhit si cao l nc s ngng t li, cui

cng trn nh thp ta thu c hn hp c cu t Ethanol chim nhiu nht (c

nng 90% phn khi lng). Hi ny i vo thit b ngng t (9) v c ngng

t hon ton. Mt phn cht lng ngng t i qua thit b lm ngui sn phm nh

(11), c lm ngui n 35oC , ri c a qua bn cha sn phm nh (12).

Phn cn li ca cht lng ngng t c hon lu v thp a trn cng vi t s

hon lu ti u. Mt phn cu t c nhit si thp c bc hi, cn li cu t c

nhit si cao trong cht lng ngy cng tng. Cui cng, y thp ta thu c

hn hp lng hu ht l cc cu t kh bay hi (nc). Hn hp lng y c nng

Ethanol l 3% phn khi lng, cn li l nc. Dung dch lng y i ra khi

thp vo ni un (8). Trong ni un dung dch lng mt phn s bc hi cung cp li

cho thp tip tc lm vic, phn cn li ra khi ni un v a vo bn cha sn

phm y.

H thng lm vic lin tc cho ra sn phm nh l Ethanol, sn phm y

c thi b.



PHN 2: TNH CNG NGH

Cc k hiu s dng trong qu trnh tnh ton:

GF: Lng hn hp u.

GD: Lng sn phm nh.

GW: Lng sn phm y.

: Nng phn khi lng ca cu t d bay hi trong hn hp u.

: Nng phn khi lng ca cu t d bay hi trong sn phm nh.

: Nng phn khi lng ca cu t d bay hi trong sn phm y.

xF: Nng phn mol cu t d bay hi trong hn hp u.

xD: Nng phn mol cu t d bay hi trong trong sn phm nh.

xW: Nng phn mol cu t d bay hi trong sn phm y.

Cu t d bay hi A: rutylic, cu t kh bay hi B: nc.



Chng 1: CN BNG VT CHT

1.1. Tnh lng hn hp.

1.1.1. Nng phn mol.

Tnh F theo kmol/h:

(kmol/h)

i nng khi lng ra nng mol:

xA =

xF =

=

= 0.16 phn mol

xD =

=

= 0.78 phn mol

xW =

=

= 0.012 phn mol

1.1.2. Lu lng hn hp u v sn phm y.

Phng trnh cn bng vt liu cho ton thp:

F = D + W (Cng thc 3.52, trang 117, [3])

79.61 = W + D (1)

Vit cho cu t d bay hi:

F.xF = D.xD + W.xW (Cng thc 3.53, trang 117, [3])

(2)

T (1) v (2) suy ra:

{



Mt khc ta c:

D + W = 1800

0.9D + 0.03 W = 1800 x 0.335

{

Gi FM l phn t lng trung bnh ca hn hp u

FM = xF.ME + (1-xF).MN

= 0,16.46 + (1 0,16).18 = 22.48 (g)

1.2. Xc nh s a ca thp.

1.2.1. ng cong cn bng - th t-x-y theo thc nghim.

Gi x, y l nng mol phn ca thnh phn lng v hi ca ru tylic (tnh

theo phn mol)

t (0C) l nhit si ca hn hp hai cu t ( 760 mmHg).

x 0 5 10 20 30 40 50 60 70 80 90

y

0 33,2 44,2 53,1 57,6 61,4 65,4 69,9 75,3 81,8 89,8

t (oC) 100 90,5 86,5 83,2 81,7 80,8 80 79,4 79 78,6 78,4

Da vo bng s liu ny ta v th ng cong cn bng ca hn hp r

tylic v nc v th biu din ng cong si.



Hnh 2: th ng cong cn bng ca hn hp ru tylic v nc.

Hnh 3: th biu din ng cong si.



Theo th ng cn bng ta xc nh c y*F = 0,5 phn mol l nng

cu t d bay hi trong pha hi cn bng vi pha lng trong hn hp u ng gi tr

xF = 0,16.

Theo th ng cong si ta xc nh c nhit si ca hn hp u

tsF=84oC, ca sn phm nh tsD = 78

oC, ca sn phm y tsW= 97oC.

x y kg/h kmol/h Nhit

si (oC)

= 0.335 xF = 0.16 yF = 0.5 F = 1800

kg/h

F = 79.61

kmol/h 84oC

= 0.9 xD = 0.78 yD = 0.8 D = 631.0345

kg/h

D = 15.34

kmol/h 78oC

= 0.03 xW = 0.012 yW = 0.11 W = 1168.9655

kg/h

W = 64.27

kmol/h 97oC

Suy ra ch s hi lu ti thiu l:

Rxmin =

(Cng thc IX.24, trg 158, [2])

Rmin =

= 0.82

Ch s hi lu thch hp l:

R = 1.3Rmin + 0.3

= 1.3 X 0.82 + 0.3 = 1.37

xc nh s a l thuyt ca thp bng cch da vo phng trnh ng

nng lm vic ca on luyn v on chng.

Phng trnh lm vic ca on luyn

y =

(Cng thc IX.20, trang 144, [2])



y =

= 0.59x = 0.33

Phng trnh lm vic ca on chng:

y = RL

Rth

th

1.y +

RL th

L

1

.(Cng thc IX.22, trang 158, [2])

Vi: L =

y =

= 2.77x 0.02

V trn th 2 ng lm vic on chng v ng lm vic on ct ta c c

s mm l thuyt l: Nlt = 12 mm. S mm l thuyt on ct l 9.4 mm v on

chng l 2.6 mm.

1.2.2. Xc nh s a thc t.

S a thc t c xc nh theo cng thc:

Ntt = tb

ltN

(Cng thc IX.59, trang 170, [2])

Vi tb l hiu sut trung bnh ca thit b, l hm ca bay hi tng i

v nht ca hn hp = f(,).

=x

x

y

y

1.

1(Cng thc IX.61, trang 171, [2])

nht: lghh = n.lg1 + (1-n)lg2

n l nng cu t th nht

n -1 l nng cu t th hai

1, 2 l nht hai cu t.

( nht ca ru tylic theo nhit c tra bng dng cho ton

h.I.18, trg 93, [2], nht ca nc theo nhit c tra bng I.102, trang 94,

[2]).

= tb = .(3

11 + 2 + 3 ) (Cng thc IX.60, trang 171, [2])

Vi: 1 l hiu sut ng vi a trn cng



2 l hiu sut ng vi a tip liu

3 l hiu sut ng vi a cui cng

- ng vi a tip liu:

bay hi:

F =

= 5.25

nht:

Ti = 84oC ta c {

lgF = OHFOHCHF xx 23 lg).1(lg

= 0,16.lg0,4132 + (1 - 0,16).lg0,3395 = -0,4555

F = 0,3503 (Cp)

Tch F.F = 0,3503 X 5,25 = 1,8391.

Tra th hnh IX.11, trang 171, [2] ta c hiu sut ca a tip liu 2 = 42

%.

- ng vi a trn cng:

bay hi:

D =

= 1.1282

nht:

Ti = 78oC ta c {

lgD = OHDOHCHD xx 23 lg).1(lg

= 0,78.lg0,4506 + (1 - 0,78).lg0,3655 = - 0,3662

D = 0.4303 (Cp)

Tch D.D = 0,4303 . 1.1282 = 0,4855. Tra th hnh IX.11, trang 171, [2],

ta c hiu sut ca a trn cng 1 = 59 %.

- ng vi a cui cng:

bay hi:

W =

= 10.1760



nht:

Ti = 97oC ta c {

lgW = OHwOHCHw xx 23 lg).1(lg

= 0.012.lg0,3424 + (1 - 0,012).lg0,2930 = - 0,5323

W = 0,2935 (Cp)

Tch W.W = 0,2935 . 10.1760 = 2.9871. Tra th hnh IX.11, trang 171, [2], ta

c hiu sut ca a trn cng 3 = 38%.

Vy hiu sut trung bnh:

tb = 3

1(1 + 2 + 3) =

3

1(59 + 42 + 38) = 46.33(%)

S a thc t l:

Ntt =

= 25.8999 (mm)

Vy thc t phi chn 25.8999 a.

Tnh ring cho phn ct:

= 20.29 (mm)

Tnh ring cho phn chng:

= 5.61 (mm)

(yF , yP , yW c xc nh t th ng cn bng hnh 1)



Chng 2: TNH NG KNH THIT B

ng knh thp: (cng thc IX.89, trang 181, [2])

D = tb

tbV

.3600.

.4 , m

Hoc D = 0,0188.tbyy

tbg

).( , m

Trong : Vtb - Lng hi trung bnh i trong thp, m3/h

tb - Tc hi trung bnh i trong thp, m/s

gtb - Lng hi trung bnh i trong thp, kg/h

(y.y)tb - Tc hi trung bnh i trong thp, kg/m2.s

2.1. ng knh on luyn.

2.1.1. Lng hi trung bnh i trong on luyn gtb.

C th xem gn ng bng trung bnh cng lng hi i ra khi a trn cng

ca thp g v lng hi i vo di cng g1 ca on luyn:

gtb = 2

1ggd , kg/h

Trong , g = GR +GP = GP(RX+1) (cng thc IX.92, trang 181, [2]).

Vi GR: lng lng hi lu, kg/h

GP: lng sn phm nh, kg/h

RX: ch s hi lu

= > g = 631.0345.(1.37+1) = 1495.5518 kg/h

Lng hi i vo a u tin ca on luyn c xc nh theo h phng

trnh cho trang 182 S tay QTTB tp 2:

dd

PP

P

rgrg

xGxGyg

GGg

..

...

11

1111

11

Trong : x1 = = 0,335 (phn khi lng)

xP = = 0,90 (phn khi lng)

G1:lng lng a th nht on luyn

r: n nhit ha hi ca hn hp i ra khi nh thp

r1: n nhit ha hi ca hn hp i vo a th nht on luyn

r1= ra .y1 + (1-y1).rb



r= ra .y + (1-y).rb

ra, rb: n nhit ha hi ca ru tylic v nc.

y = = 0,90 phn khi lng.

*Tnh r1: hn hp u vo thp 84oC nn ta phi tnh ra, rb 84

oC.

(Theo bng I.212, trang 254, [1]) ta c:

60oC: ra1 = 879.9 kJ/kg

rb1 = 2359 kJ/kg

100oC: ra2 = 812.9 kJ/kg

rb2 = 2258.4 kJ/kg

Theo phng php ni suy ta tnh ra, rb 84oC:

ra84 = ra

60 + ( )

( ) ( ) = 839.7 kJ/kg = 200.6068 kcal/kg

rb84 = rb

60 + ( )

( ) ( ) = 2298.64 kJ/kg=551.5553 kcal/kg

Vy: r1 = ra.y1 +(1-y1).rb = 200.6068.y1 + (1-y1).551.5553

= 551.5553 350.9485y1

*Tnh r: hi i ra khi nh thp nhit 78oC, tng t nh trn:

ra78 = ra

60 + ( )

( ) ( )=1066.975kJ/kg = 254.9035 kcal/kg

rb67 = rb

60 + ( )

( ) ( ) = 2313.73 kJ/kg =552.7569 kcal/kg

Vy: r = ra.y + (1- y).rb = 254,9035.0,90 +(1-0,90).552,7569

= 284.6888 kcal/kg

Vy ta c h phng trnh :

{

( )

Gii h ta c :

{

- Lng hi trung bnh i trong on luyn:

gtb = hkgggd /4609,1382

2

37.12695518,1495

2

1

- Lng lng trung bnh i trong on luyn:



Gtb = hkgGRGGG XPR /4276,751

2

338,63837.1.0345,631

2

.

2

11

- Thnh phn hi cn bng i trn on luyn:

ytb = 758.02

6159.09.0

2

1

yyd

phn khi lng

= 0,5507 phn mol

- Phn t lng trung bnh ca hn hp hi:

tbM = ytb.MA +(1- ytb).MB = 0,5507.46 + (1-0,5507).18 = 33.4196 vC

2.1.2. Tc hi trung bnh i trong on luyn.

(yy)tb = 0,065[] . ytbxtbh .. , kg/m2. (Cng thc IX.105, trang 184, [2]).

xtb, ytb: Khi lng ring trung bnh ca pha lng v pha hi tnh theo nhit

trung bnh, kg/m3.

h: Khong cch cc a trong thp,m,vi gi tr h c chn theo ng knh

thp.

[] : H s tnh n sc cng b mt.

*Tnh [] nhit trung bnh:

Nhit trung bnh trong on luyn:

ttb = Ctt oPF 81

2

7884

2

Theo bng I.242, trang 300, [1] ta c sc cng b mt ca ru v nc:

80oC: a1 = 17.3 dyn/cm (tylic)

b1 = 62.6 dyn/cm (nc)

100oC: a2 = 15.5 dyn/cm (tylic)

b2 = 58.9 dyn/cm (nc)

8.112 aaa dyn/cm

7,312 bbb dyn/cm

Cttt 012 2080100

09,020

8,1

t

a dyn/cm.

185,020

7,3

t

b dyn/cm.



Bng phng php ni suy ta tnh c sc cng b mt ca tylic v nc

81oC:

a81 = a1

80 + )8081(

t

a = 17,3 - 0,09.(81-80) = 17,21 dyn/cm

b81 = b1

80 +

)8081.(185,06.62)8081(

t

b 62.415 dyn/cm

Sc cng b mt ca hn hp:

bahh

111 (cng thc I.76, trang 299, [1])

49,13.

ba

bahh

dyn/cm

Ta thy hh < 20 dyn/cm nn chn [] = 0,8.

*Tnh khi lng ring trung bnh:

Khi lng ring ca tylic v nc: (Theo bng I.2, trang 9, [1])

- 800C: a1 = 735 kg/m3 (tylic)

b1 = 972 kg/m3 (nc)

- 1000C: a2 = 710 kg/m3 (tylic)

b2 = 958 kg/m3 (nc)

2512 aaa kg/m3

1412 bbb kg/m3

Ct 02080100

25.120

25

t

a kg/m3.

7,0

20

11

t

b kg/m3.

Theo phng php ni suy, tnh khi lng ring ca tylic v nc 81oC:

75.73325.1735)8081(80

1

81

t

aaa

kg/m3

3.971.7,097280818081

t

b

bb

kg/m

3

Khi lng ring ca hn hp (cng thc I.2, trang 5, [1]):

b

b

a

a

hh

xx

1

Vi xa, xb: Nng phn khi lng ca cc cu t trong hn hp



xa = 6175,02

335,090,0

phn khi lng

xb = 1-xa = 0,3825 phn khi lng

hh = 809.4745 kg/m3

xTB = hh = 809.4745 kg/m3

Khi lng ring ca pha hi: (cng thc I.3, trang 5, [1]):

0.

.273.

4,22 pT

pMyTB , p = p0 = 1atm

1506.181273

273.

4,22

33.4196

yTB

kg/m3

Vy tc trung bnh ca hi trong thp:

hhtbyy 587,11506,1.4745,809..8,0.065,0)( kg/m2.s

ng knh on luyn:

D = 0,0188.4

5382,0

.587,1

5692.1300

hh

Chn h = 0,35 (m) D = 0,7 m

2.2. ng knh on chng.

2.2.1. Lng hi trung bnh trong on chng gtb.

C th xem gn ng bng trung bnh cng lng hi i ra khi on chng gn

v lng hi i vo on chng g1:

gtb = 2

'' 1gg n , kg/h (Cng thc IX.96, trang 183, [2]).

V lng hi i ra khi on chng bng lng hi i vo on luyn nn:

gn = g1 = 1269.37 kg/h

Lung hi i vo an chng g1, lung lng G1 v hm lng lng x1 c

xc nh theo h phng trnh cho trang 182, S tay QTTB tp 2:

)3(

1111

)2(

111

)1(

11

.'.''.'

..''.'

''

rgrgrg

xGygxG

GgG

nn

www

w

Trong r1: n nhit ha hi ca hn hp hi i vo a th nht ca on

chng, c tnh theo cng thc:

r1= ra.y1 + (1-y1).rb



Vi y1 = yW l thnh phn cu t d bay hi (tylic) trong pha hi cn bng vi

pha lng trong sn phm y. Da vo th ng cn bng (H.1) ng vi

xW=0,012 ta c yW = 0,11 phn mol ng vi phn khi lng:

y1= 24,018.89,046.11,0

46.11,0

phn khi lng.

Theo th ng cong si (H.2) ta c sn phm y c nhit si l 97oC,

theo cc s liu 11,,,, baba rrtrr c phn tnh ton ng knh on luyn ta

c:

ra97 = ra

60 + )/(925,81737.675,19.879)6097( kgkJt

ra

= 195,4047 kcal/kg

rb97 = rb

60 + )/(945,226537.515,22359)6097( kgkJt

rb

= 458,3163 kcal/kg

r1 = ra97.y1 + (1-y1).rb

97

= 195,4047.0,24 + (1-0,24).541,341 = 458,3163 kcal/kg

Thay r1, g1, r1 vo (3):

g1.458,3163 = 1269,37.335,4052

g1 = 928,9508 kg/h

Thay vo (1):

G1 = 928,9508 + 1168,9655 = 2097,9163 kg/h

Thay vo (2):

2097,9163.x1= 928,9508.0,24 + 1168,9655.0,03

x1 = 0,123 phn khi lng

Vy lng hi trung bnh i trong on chng:

gtb = hkggg n /1604,1099

2

9508,92837,1269

2

'' 1

Lng lng trung bnh i trong on chng:

Gtb = hkgGG

/1272,13682

9163,2097338,638

2

'11

Thnh phn hi trung bnh i trong on chng:

ytb = 2

''1 nyy



Vi yn l hm lng trn a trn cng on chng xem bng hm lng hi a

th nht on luyn yn = y1 = 0,6159 phn khi lng.

ytb = 428,02

6159,024,0

(phn KL) = 0.2265 phn mol

Phn t lng trung bnh ca hn hp hi trong on chng:

'M hh = ytb.MA + (1-ytb).MB

=0,2265.46 + 0,77735.18 = 24,342 vC

2.2.2. Tc hi trung bnh trong on chng.

(yy)tb = 0,065[]. ytbxtbh '.'. ; kg/m2.s (Cng thc IX.105, trang 184, [2].

xtb, ytb: Khi lng ring trung bnh ca pha lng v pha hi tnh theo nhit

trung bnh, kg/m3.

h: Khong cch cc a trong on chng ,gi tr ca h chn theo ng knh

thp.

[]: H s tnh n sc cng b mt.

*Tnh [] nhit trung bnh on chng ttb = Ctt owF 5,90

2

9784

2

:

Tra sc cng b mt ca tylic v nc (bng I.242, trang 300, [1]), ta c :

a180 = 17,3 dyn/cm , a2

100 = 15,5 dyn/cm

b180 = 62,6 dyn/cm , b2

100 = 58,9 dyn/cm

Tnh tng t nh phn luyn:

cmdynt

aaa /355,165,10.09,03,17)805,90(

80

1

5,90

cmdynt

bbb /6575,605,12.185,06,62)805,90(

80

1

5,90

Sc cng b mt ca hn hp:

bahh

111

ba

bahh

.

hh = 12,8817 dyn/cm

*Tnh khi lng ring trung bnh pha lng:

Tra khi lng ring ca tylic v nc (bng I.2, trang 9, [1]) ta c:

a180 = 735 kg/m3 , a2

100 = 716 kg/m3

b180 = 972 kg/m3 , b2

100 = 958 kg/m3

Bng phng php ni suy ta c:



380

1

5,90/025,7255,10.95,0735)805,90( mkg

t

aaa

3801

5,90/65,9645,10.7,0972)805,90( mkg

t

bbb

Khi lng ring ca hn hp:

b

b

a

a

hh

xx

1

xa, xb: Phn khi lng trung bnh ca tylic v nc trong hn hp

xa = 1825,02

03,0335,0

2

wF xx (phn khi lng),

xb = 1- xa = 0,8175 (phn khi lung).

hh = 909,7748 kg/m3 = xt

Khi lng ring ca pha hi:

5,90273

273.

4,22

'

hhytbM

=

( ) = 0,8161 kg/m3

Vy tc trung bnh ca hi trong on chng:

hhtbyy 417,18161,0.7748,909.8,0.065,0)''(

ng knh on chng:

D = 0,0188.h

g

tbyy

tb

.417,1

1604,10990188,0

)''(

'

D =4

5,0

h , m

Chn h = 0,3 m D = 0,68 m.

V ng knh on chng v on ct khng chnh lch nhau nhiu nn ta ly

ng knh chung cho ton thp l D = 0,7m.



Chng 3: CN BNG NHIT LNG

Gi QD1 l nhit lng do hi nc cung cp un si hn hp u.

Qf l nhit lng do hn hp u mang vo thit b un si hn hp.

QF l nhit lng do hn hp u mang ra khi thit b un si hn hp

u.

Qm l nhit lng do mt mt.

Qy l nhit lng do hi mang ra khi thp chng

QR l nhit lng do lng hi lu mang vo thp.

Qh l nhit lng do hi mang ra khi thit bi ngng t hi lu.

QD2 l nhit lng do hi t un si y thp mang vo.

3.1. Cn bng nhit lng ca thit b un nng hn hp u.

QD1 + Qf = QF + Qm (8)

3.1.1. Nhit lng do hi t mang vo QD1.

QD1 = D1.r1 (Cng thc IX.150, trang 196, [2])

D1: Lng hi t cn thit un si hn hp u, kg/h.

r1: n nhit ha hi ca hi nc, J/kg.

V nhit si ca hn hp u l 840C nn nhit ca hi nc phi cao,

chn 110,70C tng ng vi nc si p sut 1,5 at (bng I.97, trang 230, [1]).

Theo ton xc nh nhit ha hi trang 255, [2] ta c nhit ha hi ca nc

110,70C l r1 = 2232,18 kJ/kg.

3.1.2. Nhit lng do hn hp u mang vo thit b un si hn hp

u Qf.

Qf = F.Cf .tf (J/h). (Cng thc I X.151, trang 196, [2]).

Vi Cf: nhit dung ring ca hn hp u, J/kg.

tf: nhit u ca hn hp, xt 250C.

Ta c: Cf = .CA + (1 - ).CB

: nng phn khi lng trong hn hp u, = 0,335

CA, CB: nhit dung ring ca tylic v nc 250C .

*Nhit dung ring ca tylic 25oC:

Nhit dung ring ca tylic theo nhit :

CA20 = 2480 J/kg. , CA

40 = 2710 J/kg.

Nhit dung ring ca tylic 250C l:



CA25 = CA

20 + kgdoJCC AA /5,25375,.112480)2025(2040

2040

*Nhit dung ring ca nc 25oC:

Ta c nhit dung ring ca nc 250C l CB25 = 4178,8 J/kg.

Vy: Cf = 0,335.2537,5 + (1-0,335).4178,8 = 3629 J/kg.

Qf = 1800.3,629.25 = 163305 kJ/h

3.1.3. Nhit lng do hn hp u mang ra khi thit b un si QF.

QF = F.CF . tF , J/h (Cng thc IX.152, trang 196, [2].

Vi: CF: Nhit dung ring hn hp i ra thit b un si.

tF = 840C.

Ta c: CF = .CA + (1- ).CB

CA ,CB :Nhit dung ring ca tylic v nc 84oC.

Tra bng nhit dung ring v theo phng php ni suy ta c:

Nhit dung ring ca tylic 84oC:

CA80 = 3.22 kJ/kg. ; CA

100 = 3.52 kJ/kg.

kgdoJCC

C AAA /32804.20

322035203220)8084(

80100

80100

84

Nhit dung ring ca nc 84oC:

CB84 = 4198 J/kg.

CF = 0,335.3280 + 0,665.4198 = 3,8905 kJ/kg.

Vy QF = 1800.3,8905.84 = 588243,6 kJ/h.

3.1.4. Nhit lng tn hao ra mi trng xung quanh Qm.

Qm = 0,05.QD1

Thay vo (*):

QD1 + Qf = QF + 0,05.QD1

QD1 = 95,0

fF QQ

=

= 447303,7895 kJ/h

Qm = 0,05.447303,7895 = 22365,1895 kJ/h

3.1.5. Lng hi t cn dng un si hn hp u. QD1 = D1.r1

D1 = hKgr

QD /3888,20018,2232

7895,447303

1

1



3.2. Cn bng nhit lng ca thp chng luyn.

Phng trnh cn bng nhit ca thp chng luyn:

QF +QD2 + QR = Qh + QW + Qm (** )

3.2.1. Lng nhit do lng lng hi lu mang vo thp QR.

QR = CR.D.RX.tR J/h (Cng thc IX.158, trang 196, [2])

Vi : RX: ch s hi lu, RX = 1,37

D: lng sn phm nh, D = 631,0345 kg/h

tR: nhit lng hi lu, tR = tD = 78oC

CR: nhit dung ring ca lng hi lu

CR = .CA + (1 - ).CB

CA, CB :nhit dung ring ca tylic v nc 78oC

Tra bng nhit dung ring ca tylic v nc 60oC v 80oC, theo phng

php ni suy ta c:

CA60 = 2.97 kJ/kg. ; CA

80 = 3.22 kJ/kg.

CA78 = CA

60 + )6078(6080

6080

AA CC

= dokgkJ ./195,3)6078(20

97,222,397,2

CB60 = 4.19 kJ/kg. ; CB

80 = 4.19 kJ/kg.

CB78 = 4,19 kJ/kg.

CR = 0,9.3,195 + 0,1.4,19 = 3,2945 kJ/kg.

Vy: QR = 3,2945.631,0345.1,37.78 = 222155,8661 kJ/h

3.2.2. Nhit lng do sn phm y mang ra QW.

QW = GW.CW.tW, J/h (Cng thc IX, trang 197, [2])

Vi: GW: Lng sn phm y, GW = 1168,9655 kg/h

CW: Nhit dung ring ca sn phm y

tW: Nhit sn phm y , tW = 97oC.

CA80 = 3.22 kJ/kg. ; CA

100 = 3.52 kJ/kg.

Bng phng php ni suy ta c: CA97 = 3,475 kJ/kg.

CB80 = 4.19 kJ/kg. ; CB

100 = 4.23 kJ/kg.

Bng phng php ni suy ta c: CB97 = 4,224 kJ/kg.

CW = CA97. + CB

97(1- )

= 0,03.3,475 + 0,97.4,224 = 4,2015 kJ/kg.



Vy nhit lng do sn phm y mang ra:

QW = 1168,9655.4,2015.97 = 476406,6292 kJ/h

3.2.3. Nhit lng do hi mang ra khi thp chng Qy.

Qy = P.(1+RX). , J/h (Cng thc IX.159, [2])

Vi: P: Lng sn phm nh, P = 631,0345 kg/h.

: Nhit lng ring ca hi nh thp, c tnh:

= A. + B.(1 - )

A, B: Nhit lng ring ca tylic v nc nh thp

: phn khi lng cu t d bay hi (tylic) trong sn

phm nh, = 0,90.

Nhit dung ring mt cu t c tnh theo:

= r + C.t

Vi: r: n nhit ha hi ca cu t .J/kg

C: Nhit dung ring ca cu t nhit t = tP = 78oC

Nhit dung ring ca tylic 78oC:

CA = 3,195 kJ/kg.

Nhit dung ring ca nc 78oC:

CB = 4,19 kJ/Kg.

( tnh phn tnh nhit lng do lng hi lu).

= (rA + CA.tP).aA + (rB + CB.tP).(1 - aA)

= rA. + rB.(1 - ) + [CA. + CB.(1 - )].tD

= r + [CA. + CB.(1 - )].tD

Vi r = rA. + rB.(1 - ) l n nhit ha hi ca hn hp, tnh phn tnh

ng knh on luyn:

r = 284,6888 kcal/kg = 1191,6504 kJ/kg

= 1191,6504 + (3,195.0,90 + 4,19.0,1).78

= 1448,6214 kJ/kg

Vy nhit lng do hi mang ra khi nh thp:

Qy = 631,0345.(1 + 1,37).1448,6214 = 2166488,292 kJ/h.

3.2.4. Nhit lng do hi t mang vo un si hn hp y thp QD.

Nhit lng tn hao Qm = 0,05.QD2 , thay vo (**), ta c:



95,0

)()(2

RFwy

D

QQQQQ

= 584,192894295,0

) 1222155,866 (588243,6) 6292,476406 22166488,29(

kJ/h

Do lng hi t s dng:

D2 = hkgr

QD /152,86418,2232

584,1928942

1

2

Lng nhit tn hao:

Qm = 0,05.QD2 = 0,05.1928942,584 = 96447,1292 kJ/h

3.3. Cn bng nhit lng ca thit b ngng tu hi lu.

Ta dng thit b trao i nhit ng chm ngng t hon ton sn phm nh.

P.(RX+1).r = Gn1.Cn.(t2 - t1) (Cng thc IX.164, [2])

Vi: P: Lng sn phm nh, P = D = 631,0345 kg/h

RX: Ch s hi lu, RX = 1,37

Gn1: Lng nc cn dng cho thit b ngng t hi lu.

t1, t2: nhit ca nc i vo v ra khi thit b ngng t hi lu,

chn t1 = 25oC, t2 = 45

oC.

Nhit trung bnh trong thit b ngng t hi lu: ttb= Ctt o35

2

21

Cn: Nhit dung ring ca nc nhit trung bnh 35oC

Cn = 4,1763 kJ/kg.

r: n nhit ha hi ca hi i ra khi nh thp, tnh trong phn

ng knh on luyn, r = 284,6888 kcal/kg = 1191,6504 kJ/kg.

Vy lng nc lnh cn dng cho thit b ngng t hi lu:

Gn1 = hkgttC

rRP

n

X /7677,21336)2545.(1763,4

6504,1191).137,1.(0345,631

).(

).1.(

12

3.4. Cn bng nhit lng ca thit b lm lnh.

Dng thit b trao i nhit ng chm.

P.CP.(t1-t2) = Gn2.Cn.(t2-t1) (Cng thc IX.167, trang 198, [2]).

Vi: Gn2: Lng nc lnh dng cho thit b, kg/h

CP: Nhit dung ring sn phm nh ngng t, J/kg.



t1, t2: Nhit u v cui ca sn phm nh khi qua thit b lm lnh, t1 = 78

oC , t2 = 35oC .

t1,t2: Nhit vo v ra ca nc lm lnh, chn t1 = 25oC,

t2 = 45oC . ttb = 35

oC.

Cn: Nhit dung ring ca nc 35oC, Cn = 4,1763 kJ/kg

CP: Nhit dung ring sn phm nh ttb = C05,56

2

3578

.

Tnh nhit dung ring ca sn phm nh 56,5oC:

CP = .CA + (1 - ).CB

Tra bng I.154, trang 172, [1] ta c nhit dung ring ca ru tylic theo nhit :

CA40 = 2,71 kJ/kg., CA

60 = 2,97 kJ/kg.

CA56,5 = CA

40 + )405,56(4060

4060

AA CC

= 9245,2)405,56(4060

71,297,271,2

kJ/kg.

Nhit dung ring ca nc nhit 56,5oC:

CB56,5 = 4,1874 kJ/kg.

Vy: CP = 0,90.2,9245 + 0,10.4,1874 = 3,0508 J/kg.

Lng nc lnh cn dng cho thit b lm lnh:

(

)

( )

( )

( ) = 991,0912 kg/h.

Nhit lng ca thit b lm lnh:



Chng 4: TNH KT CU CA THP CHNG LUYN

4.1. Kt cu a phn luyn.

4.1.1. Tnh ton.

Cc cng thc c gi tr sau c tra trang 236, [2]:

- ng knh ng hi ca chp: dh = 50 mm = 0,05 m

- S chp phn b trn a:

2

2

.1,0hd

Dn

Vi: D: ng knh trong ca thp, m.

dh: ng knh ng hi ca chp, m .

6,1905,0

7,0.1,0

2

n Chn n = 20 (chp ).

- Chiu cao chp pha trn ng dn hi:

h2 = 0,25.dh = 0,25.0,05 = 0,0125 m = 12,5 mm.

- ng knh chp:

22

).2( chhhch ddd

Vi ch: chiu dy chp, chn ch = 2,5 mm

Vy: 3303,74)5,2.250(50 22 chd mm

- Khong cch t mt da n chn chp:

S = 0 25 mm, chn S = 5 mm.

- Chiu cao mc cht lng trn khe chp:

h1 = 15 40 mm, chn h1 = 20 mm.

- Chiu cao khe chp:

x

yy

gb

.

..2

(Cng thc IX.215, trg 236, [2].

Vi: y = nd

V

h

y

...3600

.42

; Vy - lu lng hi i trong on luyn, m

3/h ;

- h s tr lc ca a chp, chn = 2;

x, y - khi lng ring trung bnh ca pha lng v hi, kg/m3. (

tnh phn tnh ng knh on luyn).

x = 809,4745 kg/m3; y = 1,1107 kg/m

3.

*Tnh Vy:



Vy =ytb

tbg

Vi:gtb = Lng hi trung bnh i trong on luyn ( tnh phn tnh ng

knh on luyn). gtb = 1382,4609 kg/h

ytb - Khi lng ring trung bnh pha hi trong on luyn, kg/m3.

= 1244,6753 m3/h

y = 81,820.05,0..3600

6753,124442

m/s

Chiu cao ca khe chp:

b = m022,04745,809.81,9

1107,1.81,8.2 2 = 22 mm

S lng khe h ca mi chp:

).4

(

2

b

dd

ci hch

Vi: gtb - Lng hi trung bnh i trong on luyn, kg/h

c - Khong cch gia cc khe, chn c = 3 mm.

i = 480642,48)22.4

503303,74(

3

2

khe

- ng knh ng chy chuyn:

z

Gd

CX

Xc

....3600

.4

;

Vi: GX - Lu lng lng trung bnh i trong don luyn, kg/h. ( tnh phn

tnh ng knh on luyn).

GX = 751,4276 kg/h.

X - Khi lng ring trung bnh ca lng trong on luyn.

Z - S ng chy chuyn, chn z = 1.

C - Tc cht lng trong ng chy chuyn,

Chn C = 0,15 m/s.

Vy: mdC 0468,01.15,0.4745,809..3600

4276,751.4

= 46,8 m

- Khong cch t mp di ng chy chuyn n a:

S1 =0,25.dC = 0,25.0,0468 = 0,0117 (m) = 11,7 (mm).

- Chiu cao ng chy chuyn trn a:

hC = (h1 +b +S) - h



Trong : h - chiu cao mc cht lng bn trn ng chy chuyn:

h = 3 2)..85,1.3600

(Cd

V

Vi: V - th tch cht lng chy qua

V = hmG

X

X /9283,04745,809

4276,751 3

h = m00965,0)0468.0..85,1.3600

9283,0(3 2

= 9,65 mm

hC = (20 + 22 + 5) 9,65 = 37,35 mm.

- Bc ti thiu ca chp trn a:

tmin = dch + 2.ch + l2

Vi: l2 = 12,5 + 0,25.dch l khong cch nh nht gia cc chp, thng ly

I2=35mm ta chn I2 = 35mm.

tmin = 74,3303 + 2.2,5 + 35 = 114,3303 mm

- Khong cch t tm ng chy chuyn n tm chp gn nht:

t1 = 122

ldd

chch

CC

Trong : C - B dy ng chy chuyn, thng ly C = 2 4, chn C = 3 mm

l1 - khong cch nh nht gia ng chy chuyn v chp,

chn l1 = 75 mm

Vy: t1 = mm07,141755,22

3303,743

2

8,46

4.1.2. Cc kt cu a phn luyn.

- ng knh ng hi: dh = 50 mm

- S chp: n = 20 chp

- ng knh chp: dch = 74,3303mm

- Chiu cao chp trn ng dn hi: h2 = 12,5 mm

- Khong cch t mt a n chn chp: S = 5 mm

- Chiu cao mc cht lng trn khe chp: h1 = 20 mm

- Chiu cao khe chp: b = 22 mm

- Khong cch gia cc khe: c = 3 mm

- S khe h ca mi chp: I = 48 khe

- ng knh ng chy chy chuyn: dC = 46,8 mm

- Chiu cao lp cht lng trn ng chy chuyn: h = 9,65 mm

- Khong cch t mp di ng chy chuyn n a: S1 = 11,7 mm



- Chiu cao ng chy chuyn trn a: hC = 37,35 mm

- B dy ng chy chuyn: C = 3 mm

- B dy chp: ch = 2,5 mm


t1 = 141,07 mm

- Khong cch gia hai tm chp: tmin=114,3303 mm

- Khong cch nh nht gia hai chp: l2 = 35 mm

- Khong cch nh nht gia chp v ng chy chuyn: l1 = 75 mm

4.2. Kt cu a on chng.

4.2.1. Tnh ton.

Cc cng thc c gi tr sau c tra trang 236, [2]:

- ng knh ng hi ca chp, thng chn: 50; 75; 100; 125; 150 mm.

Ta chn: dh = 50 mm = 0,05 m.

- S chp phn b trn a:

2

2

.1,0hd

Dn

Vi: D : ng knh trong ca thp, tnh phn tnh ng knh thp,

D = 0,7 m.

dh: ng knh ng hi ca chp, m

6,1905,0

7,0.1,0

2

n (chp)

Chn n = 20 (chp )

- Chiu cao chp pha trn ng dn hi:

h2 = 0,25.dh = 0,25.0,05 = 0,0125 m = 12,5 mm.

- ng knh chp:

22

).2( chhhch ddd

Vi: ch: chiu dy chp, chn ch = 2,5 mm.

Vy: 3303,74)5,2.250(50 22 chd mm

- Khong cch t mt da n chn chp:

S = 0 25 mm, chn S = 5 mm.

- Chiu cao mc cht lng trn khe chp:

h1 = 15 40 mm, chn h1 = 20 mm

- Chiu cao khe chp:



x

yy

gb

.

..2

(Cng thc IX.215 trang 236, [2]).

Vi: y = nd

V

h

y

...3600

.42

; Vy -lu lng hi i trong on chng, m

3/h.

- H s tr lc ca a chp, chn = 2

x ,y - khi lng ring trung bnh ca pha lng v hi ,kg/m3. tnh

phn tnh ng knh on chng:

x = 909,7748 kg/m3; y = 0,7953 kg/m

3.

*Tnh Vy :

Vy =ytb

tbg

'

Vi:

l lu lng hi trung bnh i trong on chng.

= 1099,1604 kg/h.

ytb - khi lng ring trung bnh pha hi trong on chng , kg/m3.

Vy =

= 1382,07 m3/h

y = 78,920.05,0..3600

07,1382.42

m/s.

Chiu cao ca khe chp:

b = m017,07748,909.81,9

7953,0.78,9.2 2 = 17 mm.

- S lng khe h ca mi chp:

).4

(

2

b

dd

ci hch

Vi: c - Khong cch gia cc khe, chn c = 3 mm.

i = 4032,39)17.4

503303,74(

3

2

khe.

- ng knh ng chy chuyn:

z

Gd

CX

Xc

....3600

.4

;

Vi: GX - lu lng lng trung bnh i trong on chng, kg/h. tnh phn

tnh ng knh on chng. GX = 1368,1272 kg/h.

X - khi lng ring trung bnh ca lng trong on chng,

X = 935,17 kg/m3

z - s ng chy chuyn, chn z = 1.



C - tc cht lng trong ng chy chuyn, chn C = 0,15 m/s.

Vy: mdC 06,01.15,0.7748,909..3600

1272,1368.4

= 60 mm.

- Khong cch t mp di ng chy chuyn n a:

S1 =0,25.dC = 0,25.0,06 = 0,015 (m) = 15 (mm).

- Chiu cao ng chy chuyn trn a:

hC = (h1 +b +S) - h.

Trong : h - chiu cao mc cht lng bn trn ng chy chuyn:

h = 3 2)..85,1.3600

(Cd

V

Vi: V - Th tch cht lng chy qua.

V = hmG

X

X /5038,17748,909

1272,1368 3

h = m0114,0)06.0..85,1.3600

5038,1(3 2

= 11,4 mm

hC = (20 + 11,34 + 5) - 11,9 = 24,44 mm.

- Bc ti thiu ca chp trn a:

tmin = dch + 2.ch + l2

Vi: l2 = 12,5 + 0,25.dch, l khong cch nh nht gia cc chp.

Ly l2 = 35 mm.

tmin = 74,3303 + 2.2,5 + 35 = 114,3303 mm.


t1 = 122

ldd

chch

CC

Trong : C - B dy ng chy chuyn, chn C = 3 mm.

l1 - Khong cch nh nht gia ng chy chuyn v chp.

Chn l1 = 75 mm.

Vy: t1 = mm6652,147755,22

3303,743

2

60

4.2.2. Cc kt cu a phn chng.

- ng knh ng hi: dh = 50 mm

- S chp: n = 20 chp

- ng knh chp: dch = 74,3303 mm

- Chiu cao chp trn ng dn hi: h2 = 12,5 mm

- Khong cch t mt a n chn chp: S = 5 mm



- Chiu cao mc cht lng trn khe chp: h1 = 20 mm

- Chiu cao khe chp: b = 17 mm

- Khong cch gia cc khe: c = 3 mm

- S khe h ca mi chp: i = 40 khe

- ng knh ng chy chy chuyn: dC = 60 mm

- Chiu cao lp cht lng trn ng chy chuyn: h = 11,4 mm

- Khong cch t mp di ng chy chuyn n a S1 = 15 mm

- Chiu cao ng chy chuyn trn a: hC = 30,6 mm

- B dy ng chy chuyn: C = 3 mm

- B dy chp: ch = 2,5 mm


t1 = 147,6652 mm

- Khong cch gia hai tm chp: tmin = 114,3303mm

- Khong cch nh nht gia hai chp: l2 = 35 mm

- Khong cch nh nht gia chp v ng chy chuyn l1 = 75 mm .



PHN 3: TNH C KH THIT B CHNH

I. Tnh thn thit b chnh.

Thp chng luyn p sut kh quyn P = 1,5 at = 1,47.105 N/m2 l p sut

thp v trung bnh nn chn thn thp hnh tr hn (theo trang 360, [2]).

Chiu dy thn hnh tr lm vic di p sut P (cng thc XIII.8, trang 360,

[2]).

CP

PDS t

][2

.. m

Trong : Dt - ng knh trong ca thp, m.

- H s bn ca thnh hnh tr theo phng dc.

C H s b sung do n mn, bo mn v dung sai v chiu dy, m.

[ ]- ng sut cho php ca vt liu.

Tra bng XIII.9, trang 364, [2], ta thy thp X18H10T ph hp vi thn hnh tr

hn c dng vi thit b lm vic p sut thp v trung bnh (



(1) [ k] = 26

6

/10.69,2071.6,2

10.540mN

(2) [k] = 26

6

/10.67,1461.5,1

10.220mN

Ta chn gi tr b nht tnh tip [] = 146,67.106 N/m2

Tra bng XIII.8, trang 362, [2]vi kiu hn tay bng h quang in, hn gip mi

hai bn ta chn h s bn mi hn h = 0,95.

I.2. Tnh P.

Trong thp l hn hp lng - kh nn p sut lm vic bng tng s p sut Pmt

hi v p sut thy tnh Pt ca ct cht lng.

Pmt = 1,5 at = 147150 N/m2.

p sut thy lc ca ct cht lng c xc nh:

Pt = g.1.Ht , N/m2 (cng thc XIII.10, trang 360, [2]:

Trong : t - Khi lng ring ca cht lng, kg/m3

m bo kh nng chu ng ca thp khi gp trng hp lm vic bt

thng ta ly t l khi lng ring ln nht ca cht lng trong thp, ngha l

t=W.

Ti nhit si 97oC ta tra c :

;

Nng phn khi lng tng ng y thp l:

= 0,1825 (phn khi lng)


0011054,01,960

8175,0

85,718

1825,01

b

b

a

a

hh

xx

hh = t = 904,6896 kg/m3 .

+ Ht - Chiu cao ct cht lng, m (ly chiu cao ln nht = chiu cao thp)

Ht = Ntt(h + ) + 0,8 , m

Vi: Ntt : S a thc t, Ntt = 25,8999 a

h : Khong cch gia cc a, h = 0,35 m

: B dy ca a, chn = 0,003 m

Ht = 25,8999.(0,35 + 0,003) + 0,8 = 9,9423 m

Vy: Pt = 9,81.904,6896.9,9423 = 88237,962 N/m2

P = Pmt + Pt = 147150 + 88237,962 = 235387,962 N/m2



Vi vt liu bn, ta c:

50944,59195,0.962,235387

10.67,146.

][ 6h

P

nn ta b qua P mu s khi tnh S.

I.3. Tnh C.

C = C1 + C2 + C3 m

Trong : C1 H s b sung do n mn, xut pht t iu kin n mn vt

liu ca mi trng. y ta ly C1 = 1 mm, tnh cho thi gian lm vic t 15 20

nm, vi n mn vt liu l 0,05 0,1 mm/nm.

C2 - i lng b sung do bo mn khi nguyn liu c ht rn

chuyn ng vi vn tc ln, y C2 c b qua .

C3 - i lng b sung do dung sai ca chiu dy tm vt liu, vi

vt liu X18H10T th C3 = 0,22 mm (tra bng XIII.9, trang 364, [2])

Vy C = 1 + 0,22 = 1,22 mm

Do

S = mmmCPDt 81,100181,010.22,1

95,0.10.67,146.2

962,235387.7,0

].[2

. 36

I.4. Kim tra ng sut theo p sut th.

).(2

)].([ 01

CS

PCSD

2,1

C (cng thc XIII.26, trang 365, [2]:

Po: p sut th, c tnh:

P0 = Pth + Pt

Pth: p sut th thy lc, theo bng XIII.5, trang 358, [2] th Pth = 1,5.P

Pth = 1,5.235387,962 = 353081,943 N/m2

Pt : p sut thy tnh ca nc

Pt = .g.Ht = 960,1. 9,81.9,9423 = 93642,358 N/m2.

Po = 353081,943 + 93642,358 = 446724,201 N/m2

Ta c: VT = 95,0).22,181,1.(2

201,446724)].22,181,1(7,0[

= 514071,5605 N/m2

VP =2,1

10.67,146 6 = 122,225.106 N/m2 > VT

Vy S = 1,81 mm l tha mn, tuy nhin chu c ti trng ca thp v

tng tnh bn vng ca thp ta chn b dy thp l S = 4 mm.



II. Tnh y v np thit b.

Thng thng ngi ta dng y v np elip vi thit b c thn hn thng

ng chu p sut trong ln hn 7.104 N/m2. Trong trng trng hp thit k thp

chng luyn lm vic p sut kh quyn nn ta s dng y v np c g c dng

elip c ng knh trong l 0,7 m. Chn vt liu ca y v np ging nh vt liu

ca thn thp. Theo hnh XIII.11, trang 381, [2], ta c:

Chiu cao phn li y:

hb = 0,25.Dt = 0,25.0,7 = 0,175 m.

Chn chiu cao ca g l 25 mm.

B dy y v np thit b (cng thc XIII.47, trg 385, [2]:

Ch

D

Pk

PDS

b

t

hk

t

.2

..]..[8,3

.

, m

Trong h - h s bn ca mi hn hng tm, tra bng XIII.8, trang 362, [2]

chn h = 0,95.

k - H s khng th nguyn, chn k = 1.

C - i lng b sung, C = 0,00122 m.

V 30944,591..][

hkP

nn b qua P mu s khi tnh S.

Vy: S = 00184,000122,0175,0295,011067,1468,3

962,2353877,06

2

m=1,84 mm

Do: S - C = 1,84 1,22 = 0,62 < 10 nn thm 2mm vo gi tri S tnh trn.

Vy: S = 3,7 mm, an ton ta chn S = 4 mm.

Kim tra ng sut theo p sut thy tnh:

iu kin tha mn:

).(...6,7

)].(.2[ 02

CShk

PCShD

bh

bt

2,1

c , N/m2 (Cng thc XIII.49, trang 386, [2].

)00122,0004,0.(175,0.95,0.1.6,7

201,446724)].00122,0004,0.(175,0.27,0[ 2 62442034,98 N/m2

66

10.225,1222,1

10.67,146

2,1c

N/m2 >

Vy b dy ca y v np thp S = 4mm l tha mn.

III. Tnh b dy lp cch nhit.

trnh tn tht nhit cho mi trng xung quanh, m bo cho qu trnh

chng luyn t hiu sut cao nht th ta phi trang b cho thp chng luyn mt lp

cch nhit.



Chn vt liu cch nhit l bng thy tinh c h s dn nhit nh:

= 0,0372 W/m.

Ta gi thit nh sau:

- Nhit khng kh: tkk = 25oC.

- Nhit bn ngoi lp cch nhit: t = 50oC.

- Xem y l qu trnh nhit n nh qua vch phng.

- m bo kh nng cch nhit cho ton thp ta chn nhit lm vic

trong thp l 100oC.

Nhit ti ring ra mi trng xung quanh:

q = t. , W/m2

Trong : t - hiu s nhit gia tng bn ngoi ca thit b vi mi

trng: t = 50 - 25 = 25oC.

- h s cp nhit t b mt thit b ra ngoi mi trng.

= 4.98,1 t (cng thc V.75, trg 24, [2]:

= 4274,425.98,1 4 W/m2. .

q = 25. 4,427 = 110,685 W/m2

Hiu s nhit gia nhit trong thp v nhit mt ngoi thp:

t1 = 100 - 50 = 50oC .

Mt khc ta c:

t1 = q. r

Vi : r l nhit tr tng cng, m2./W. c tnh:

r = r1 + r2 + r3

Trong :

- r1: Nhit tr lp cn, r1 = 0,387.10-3 m2./W. (Tra bng V.1, trang 4, [2]).

- r2: Nhit tr thnh thit b, r2 = / = 4.10-3/16,3 = 0,2454.10-3 m2./W.

- r3: Nhit tr lp cch nhit dy , r3 = / = /0,0372 m2./W

Ta c: r = t1/q = 50/110,685 = 0,4517 m2./W

Suy ra: r3 = r - r1 - r2 = 0,4517 0,387.10-3 - 0,2454.10-3 = 0,4511 m2./W

= r3.0,0372 = 0,01678 m = 16,78 mm.

m bo cch nhit tt ta chn lp cch nhit c b dy 20 mm.



IV. Tnh ng knh cc loi ng dn.

ng knh ng dn (cng thc II.36, trang 369, [1]):

..3600

.4VD , m

Vi: V : lu lng th tch, m3/h

: tc trung bnh ca cht lng v kh (cho bng II.2, trang 369,

[1]).

IV.1. ng knh ng dn hn hp u vo a tip liu.

Nhit si ca hn hp u vo thp l 840C (tra bng I.2, trang 9, [1]) ta c:

)8084(80100

801008084

aaaa

= 731,2 kg/m3

)8084(80100

801008084

bbbb

= 969,2 kg/m3


B

B

a

A

hh

xx

1

a, b: Khi lng ring ca tylic v nc

xA, xB: Nng phn khi lng ca tylic v nc.

001144,02,969

665,0

2,731

335,01

hh

hh = 873,91 kg/m3

Lu lng th tch cht lng chy trong ng:

V = )/(06,291,873

1800 3 hmG

hh

F

Hn hp t chy vo thp nn chn vn tc cht lng i trong ng l = 0,20

m/s.

Vy ng knh ng dn l:

)(60)(06,0.3600.20,0

06,2.4mmmD



IV.2. ng knh ng dn t thit b ngng t hi lu v thp.

Nhit ca lng hi lu l 78oC, khi lng ring ca lng hi lu tnh tng t

nh trn ta c:

= 736,9 kg/m3 ;

= 971,75 kg/m3

75,971

1,0

9,736

9,01

hh

= 755,15 kg/m3

Lu lng th tch cht lng chy trong ng:

)/(145,115,755

0345,631.37,1. 3 hmGR

Vhh

PX

Hn hp t chy vo thp nn ta chn = 0,25 m/s

Vy ng knh ng dn l:

04,0.3600.25,0

145,1.4

D (m) = 40 (mm).

IV.3. ng knh ng dn hi ra khi nh thp.

Lng hi i ra khi nh thp g = 1495,5518 kg/h. tnh phn tnh ng

knh on luyn.

Phn t lng trung bnh ca hi i ra khi nh thp:

MTB = 46.0,8 + 18.0,2 = 40,4 vC

Khi lng ring ca hi ra khi nh thp 78oC l:

)/(4028,1)78273.(4,22

273. 3mkgMTB

(Cng thc I.3, trang 5, [1]).

Lu lng hi i trong ng:

V = )/(12,10664028,1

5518,1495 3 hmgd

Chn vn tc hi i trong ng l: = 20 m/s .

Vy ng knh ng dn hi l:

)(3,137)(1373,0.3600.20

12,1066.4mmmD

IV.4. ng knh ng dn sn phm y.

Khi lng ring ca sn phm y 97oC tnh phn tnh c kh thit b

chnh: hh = 950,53 kg/m3.

Sut lng sn phm y l: GW = 1168,9655 kg/h.



Lu lng th tch:

V = )/(23,153,950

9655,1168 3 hmG

hh

Chn vn tc cht lng i trong ng l: = 0,26 m/s.

Vy ng knh ng dn sn phm y:

)(41)(041,0.3600.26,0

23,1.4mmmD

IV.5. ng knh ng dn vo y thp un si li.

Sut lng hi vo y thp l: = 928,9508 kg/h.

Vi: [ ( ) ]

( )

( )

( ) = 0,6944 kg/m3.

V =

= 1337,7748 m3/h.

Ta chn vn tc hi vo y thp l: w = 25 m/s.

D =

= 0,138 m = 138 m.

IV.6. ng knh dn cht lng y thp.

Sut lng cht lng vo ni un l: = 2097,9163 kg/h. tnh phn

ng knh on chng.

= 0,053 phn mol = 0,1251 phn khi lng.

= 921,2711 kg/m3

V =

= 2,2772 m3/h

Chn vn tc cht lng vo ni un l: = 0,2 m/s.

D =

= 0,0635 m = 63,5 mm.



V. Chn bch.

Mt bch l b phn quan trng dng ni cc phn ca thit b cng nh ni

cc b phn khc vi thit b. V thp lm vic p sut kh quyn nn ta chn kiu

bch lin.

V.1. Bch ni thn thit b, np v y.

Theo bng IX.5, trang 170, [2] ng vi Dt = 700 mm, khong cch gia hai a

l 350 mm th s a gia hai mt bch lin tip l 4. Vi 25,8999 a ta c tt c l 8

b bch ni thn, np v y.

Theo bng XIII.27, trang 419, [2] ta chn bch kiu 4 ni cc on thn thp,

ni np v ni y. m bo bch chu c khi gp trng hp lm vic bt

thng ta chn p sut Py bng p sut th P0 tnh trong phn c kh thit b

chnh, Py 0,3.106 N/m2

S liu ca bch c cho bng sau:

Py.106

N/m2 Dt

(mm)

Kch thc ni (mm) Kiu bch

D Db D1 D0

Bulng 4

db z h h1

0,3 700 830 780 750 711 M20 24 20 3

Gia hai bch c mt lp lt b mt m bt kn m bo kn ca thp,

kch thc ca b mt m bt kn (Tra bng XIII.31, trang 433, [2]), ng vi

Dy=700 mm ta c D2 = 750 mm, D4 = 730 mm.

V.2. Bch ni ng dn vi thit b.

ni cc ng dn vi thn thit b ta dng kiu bch lin bng kim loi en.

Tra bng XIII.26 trang 409 S tay QTTB tp 2 ta c bng s liu sau:

Py.106

N/m2

Dy (mm)


Dn D D D1

Bulng 1

db z h

0,25 0,6

40 45 130 100 80 M12 4 14



Py.106

N/m2

Dy (mm)


Dn D D D1

Bulng 1

db z h

0,25 0,6

50 57 140 110 90 M12 4 14

0,25 0,6

70 76 160 130 110 M12 4 14

0,25 0,6

150 159 260 225 202 M16 8 16

ng dn c ni vi thit b thng qua mi ghp tho c, do ta phi

dng on ng ni, l on ng ngn c mt bch. Kch thc chiu di ng ni ta

chn bng XIII.32, trang 434, [2]:

Dy (mm) 40 50 70 100 150

l (mm) 100 100 110 120 130

VI. Tnh ti trng ca thp.

Khi lng ca thp bao gm tng khi lng ca thn thp, y, np, lp

cch nhit, cht lng trong thp, bch v a.

VI.1. Khi lng ca thn thp.

Tnh theo cng thc: ).(4

.. 221 tn DD

HG

, kg .

Trong : H: Chiu cao thp cha k y v np.

H = Ntt(h + )

+ h - Khong cch gia cc a, h = 0,35 m.

+ - B dy ca a, chn: = 0,003 m.

H = Ntt(h + ) = 25,8999.(0,35 + 0,003) = 9,1427 m.

: Khi lng ring ca thp X18H10T, = 7900 kg/m3

Dt : ng knh trong ca thp, Dt = 0,7 m.

Dn : ng knh ngoi ca thp

Dn = Dt + 2.S = 0,7 + 2.0,004 = 0,708 m.



Vy: kgG 6514,638)7,0708,0(4

.7900.1427,9 221

VI.2. Khi lng ca y v np elip c g.

Tra bng XIII.11, trang 384, [2] ta c khi lng ca y v np elip c g

ng vi ng knh trong ca thp 0,7 m, chiu dy y v np 4 mm, chiu cao g

25 mm l:

G2 = 2.19 = 38 kg.

VI.3. Khi lng ca cht lng trong thp.

Xem cht lng chim y thp, ta s b qua khi lng ca cc ng chy

chuyn v cc chp.

G3 = V.hh (kg)

Trong : V - Th tch cht lng.

V = 5167,34

1427,9.7,0.

4

.. 22

HDt m3 .

hh : khi lng ring ca cht lng, ly khi lng ring ln nht,

hh = 904,6896 kg/m3. tnh phn tnh thn thit b chnh.

Vy: G3 = 3,5167.904,6896 = 3181,523 kg.

VI.4. Khi lng ca cc a.

n gin ta coi a l mt tm trn khng b khot l c chiu dy nn khi

lng ca 25,8999 a l:

G4 = 25,8999. D.4

t2.. = kg6024,2827900.003,0.7,0.

4.258999 2

VI.5. Khi lng lp cch nhit.

B dy lp cch nhit l 20 mm.

Khi lng bng thy tinh bao quanh thn thp, c phn g ca y v np:

m1 = )025,0.2).()02,0.((4

.22 HDD nn

= kg41)05,01427,9).(708,0728,0.(4

.200 22

Khi lng phn bng thy tinh ph y v np:

m2 = 2.Fy.0,02.

Ta c: Fy = hg.Dt.3,14 + 4 .(

)

Vi: a = b = Dt/2 = 0,35 m

C = hb = 0,175 m



hg = 0,025

Thay s vo ta c:

Fy = 0,025.0,7.3,14

+ 4. . (

)

= 0,5866 (m2)

m2 = 2.0,5866.0,02.200 = 4,6928 kg.

Vy khi lng lp bng cch nhit:

G5 = m1 + m2 = 41 + 4,6928 = 45,693 kg .

VI.6. Khi lng ca bch.

- Khi lng cc bch ni thn, np v y:

Mt cch gn ng ta c khi lng mt bch n (khng tnh n cc l khot

vn bulng nn b qua khi lng ca cc bulng):

m = kghDD 7445,227900.02,0.4

).711,083,0(..4

).( 222

0

2

Dng 8 b bch = 16 bch n, nn khi lng ton b 8 b bch l:

m1 = 16. m = 16.22,7445 = 363,912 kg.

Khi lng cc bch ni ng dn vi thn thp:

- Bch ni ng dn hn hp u vo thp:

kghDDm nd 42,17900.014,0).057,014,0(4

.)..(4

2222

Vy khi lng cp bch ny:

m2 = 2.1,42 = 2,84 kg

- Bch ni ng dn hi ra khi nh thp:

m3 = kg4,87900.016,0).159,026,0.(4

.2 22

- Bch ni ng dn dung dch y:

m4 = 2. kg58,27900.014,0).045,013,0.(4

22

- Bch ni ng dn lng hi lu:

m5 = 2. kg58,27900.014,0).045,013,0.(4

22

- Bch ni ng dn hi t:



m6 = 2. kg4,87900.016,0).159,026,0.(4

22

- Bch ni ng dn nc ngng:

m7 = m5 = 2,58 kg

Vy tng cc loi bch ni thn, np, y v ng dn:

G6 = m1 + m2 + m3 + m4 + m5 + m6 + m7

= 363,912 + 2,84 + 8,4 + 2,58 + 2,58 + 8,4 + 2,58

= 391,292 kg.

Tng khi lng ton thp:

G = G1 + G2 + G3 + G4 + G5 + G6

= 638,6514 + 38 + 3181,523 + 282,6024 + 45,693 + 391,292

= 4577,7618 kg.

VII. Chn tai treo, chn .

VII.1. Chn tai treo.

Ta dng 4 tai treo kiu VII, hnh XIII.21, trang 436, [2] do ti trng trn mt tai

treo:

G =

N9608,11226

4

81,9.7618,4577

Theo bng XIII.36, trang 438, [2] th ta chn tai treo c cc s liu sau:

Ti trng cho php trn mt tai treo: Gcp = 25 000 N > G

B mt : F = 173.10-4 m2

Ti trng cho php ln mt b mt :

qcp = 14500000173,0

25000

F

Gcp N/m2

Ti trng thc t ln mt b mt :

q = 2717,6489570173,0

9608,11226

F

G N/m2 < qcp = 1,45.10

6 mm.

L B B1 H S l a d

150 120 130 215 8 60 20 30



VII.2. Chn chn .

Ta chn chn kiu III, trang 436, [2] vi ti trng trn mt chn l

G=11226,9608 N nn ta chn chn c cc s liu sau:

Ti trng cho php trn mt chn: Gcp = 25 000 N > G

B mt : F = 444.10-4 m2

Ti trng cho php ln mt mt :

qcp =

= 2/5600000

000444,0

25000mN

Ti trng thc t ln mt chn :

q = 2/250000000444,0

9608,1126mN < qcp = 320 000 mm

L B B1 B2 H h s l d

250 180 215 290 350 185 16 90 27



PHN 4: TNH THIT B PH

I. Tnh ton thit b ngng t hi lu.

nng cao kh nng phn tch cc cu t trong qu trnh phn tch ta cn

to ra qu trnh tip xc gia pha lng v pha hi, diu ny c thc hin trong

thp. nng cao tinh khit ca sn phm nh v trnh hin tng kh a

nhng a trn cng ta cho mt phn sn phm nh hi lu tr li thp, iu ny

c thc hin nh thit b ngng t hi lu. y l ni xy ra qu trnh trao i

nhit gia hi i ra t nh thp vi nc lm lnh, lng nhit trao i y ng

bng nhit lng cn cung cp ha hi lng hi i ra khi nh thp. Trong iu

kin ny ta dng thit b ngng t kiu ng chm, h thng ny c u im l gn,

chc chn, t tn kim loi, b mt truyn nhit ln, d kim tra quan st, sa cha,

lm v sinh.

Trong thit b ny, tc nhn nng l hi i ra t nh thp (ru tylic) c

tinh khit cao nn ta cho i bn ngoi chm ng, cn tc nhn lm lnh l nc lnh

ta cho i bn trong cc ng d lm v sinh khi cc cht bn bm trong ng.

m bo truyn nhit trit , tit kim lng nc ta cho hai lu th chuyn ng

ngc chiu, hi i t trn xung, nc i t di ln .

y ta tnh ton thit b ngng t hon ton lng hi i ra khi thp.

Nhit ca hi l 78oC .

Nhit u ca nc c chn 25oC.

Nhit cui ca nc c chn 45oC, trnh hin tng cc mui d kt

ta v ng cn li trn b mt trong ng.

Trong phn cn bng nhit lng cho thp ta tnh lng nc cn thit

ngng t hon ton hi ra khi nh thp l: Gn2 = 991,0912 kg/h.

Lng nc lnh cn dng cho thit b ngng t hi lu Gn1 = 31336,7677.

Hiu s nhit trung bnh gia hai lu th chuyn ng ngc chiu c

xc nh theo cng thc V.8 trang 5 S tay QTTB tp 2:

2

1

21

lnt

t

ttt

, .

Trong t1 v t2 l hiu s nhit ln v nh ca hai lu th, . y ta

c:

t1 = 78 - 25 = 53 0C, t2 = 78 45 = 33

0C



Nn: Ct 0213,42

33

53ln

3353

Nhit trung bnh ca nc lm lnh c tnh theo cng thc V.21, trang 10,

[2]:

t = T1 - Cto787,35213,4278

I.1. i vi pha hi.

H s cp nhit c tnh theo cng thc V.100, trang 28, [2]:

1 = 41

32

..

....15,1

Ht

gr

, W/m2.

Trong : r: n nhit ngng, r = r = 284,6888 kcal/kg = 1191,65 J/kg ( tnh

phn tnh ng knh on luyn).

: Khi lng ring ca lng ngng, = 755,15 kg/m3.

H: Chiu cao ng, chn H = 2 m.

: H s dn nhit ca lng ngng, W/m., c xc nh theo

cng thc I.32, trang 123, [1]:

= 3...M

CA P

, W/m.

Vi: A H s ph thuc mc lin kt ca cht lng. A = 3,58.10-8,

v cht lng lin kt (nc, ru tylic).

CP : Nhit dung ring ng p ca cht lng, J/kg., xem cht

lng l ru tylic nn CP78 = 3,195 kJ/kg..

= 755,15 kg/m3 tnh trn.

M: Phn t lng trung bnh ca lng ngng.

M = 0,78.46 + (1-0,78).18 = 39,84 vc

Vy: = 2303,084,39

15,755.15,755.3195.10.58,3 38 ,W/m.

: nht ca lng ngng, = 0,4233.10-3 N.s/m2

Ta c:

= 0,591 Cp

= 0,435 Cp

= 0,4506.10-3 Ns/m2.



ttt n 1 T1 :hiu s gia nhit ngng tn v nhit mt tng

tip xc vi hi ngng, tn = 78 0C, ly tT1 = 75

0C.

t1 = 30C .

Vy h s dn nhit:

1 = 0381,26942.3.10.4506,0

)2303,0.(81,9.)15,755.(1191650.15,1 4

3

32

(W/m2.)

Nhit ti ring v pha hi ngng t:

q1 = 1.t1 = 2694,0381.3 = 8082,1143 W/m2

I.2. i vi pha nc lm lnh.

H s cp nhit tnh theo cng thc V.33, trang 11, [2]:

d

Nu

.2

Trong : : H s dn nhit ca nc nhit trung bnh 35,7870C:

Ta c:

= 0,597 W/m..

= 0,642 W/m..

= 0,6332 W/m..

d: ng knh ng truyn nhit, chn d = 0,03 m.

Nu: Chun s Nuyxen, c tnh theo V.40 trang 14 S tay QTTB

tp 2.

Nu = 25,043,08,0

1 )Pr

Pr.(Pr.Re..021,0

t

Vi: Prt: Chun s Pran ca dng tnh theo nhit trung bnh ca

tng. V chnh lch nhit gia tng v dng nh nn 1Pr

Pr

t

.

Re: Chun s Renoydn, gi s nc chy ri vi Re = 104

Pr: Chun s Prant, tnh theo V.35 trang 12 S tay QTTB tp 2:

.Pr P

C

Vi: CP: Nhit dung ring ng p ca nc 35,7870C, ta c:

CP=4175,9825 J/kg.

: nht ca nc 35,7870C.



Tra bng ta c: = 0,757.10-3 N.s/m2

: H s dn nhit ca nc 35,7870C, = 0,6332 W/m.

Pr = 56332,0

10.757,0.9825,4175 3

1: H s hiu chnh tnh n nh hng ca t s gia chiu di l

v ng knh d ca ng, theo bng V.2 th 1 = 1.

Nu = 0,021.1.(104)0,8.50,43 = 66,4931

Vy 2 = 4477,140303,0

6332,0.4931,66 W/m2.

Nhit ti ring v pha nc:

q2 = 2.t2

t2 l hiu s nhit gia nhit thnh bn trong tng ng vi nhit

trong dng nc, chn t2 = 50C.

q2 = 1403,4477.5 = 7015,5885 W/m2.

q =

2

21 qq(8082,1143 + 7015,5885)/2 = 7548,8514 W/m2

I.3. S ng truyn nhit v cch sp xp.

B mt truyn nhit:

F = q

rRP

q

Q X ).1.( m2

Vi: r - n nhit ngng t ca sn phm nh, r = 849750 J/kg

F = 7637,463600.8514,7548

849750).137,1.(0345,631

(m2)

S ng cn dng:

n = 2482.03,0.

7637,46

..

Hd

F(ng).

Ly s ng l 241 ng. Theo bng V.11, trang 48, [2], ng vi s ng l 241 v

sp xp theo hnh 6 cnh u th ta b tr 241 ng thnh 8 vng 6 cnh vi s ng

trn ng cho chnh ca hnh 6 cnh l 17 ng, s ng trong mi hnh vin phn

dy th nht l 4 ng v tng s ng trong cc hnh vin phn l 24 ng.

Theo cng thc V.140, trang 49, [2] th ng knh trong ca thit b c tnh:

D = t.(b -1) + 4.d , m

Vi: d: ng knh ngoi ca ng truyn nhit.



d = 0,03 + 0,0015.2 = 0,033 m

t: Bc ng, t = 1,2.d = 0,0396 m

b: S ng trn ng cho chnh ca hnh 6 cnh, b = 17

D = 0,0396.(17 - 1) + 4.0,033 = 0,7656 m.

Chn D = 0,8 m.

Vy thit b ngng t c ng knh trong l 0,8 m, gm 241 ng xp theo hnh

lc gic u gm 8 vng. Mi ng di 2 m, ng knh trong 0,03 m, dy 0,0015 m.

II. Thit b gia nhit nhp liu.

- un si dung dch nhp liu a vo thp ta dng hi nc bo ha

c p sut tuyt i l 1,5 at

- ng i ca lu cht: Hi nc bo ha i ngoi ng cn dng nhp liu

i trong ng.

Dng nng: 110,7oC(hi bo ha) 110,11736oC (lng ngng)

Dng lnh: 84oC(lng si) 25oC (dung dch)

- Chnh lch nhit u vo: tv = 110,7 84 = 26,7oC

- Chnh lch nhit u ra: tr = 110,7 25 = 85,7oC

- Chnh lch nhit trung bnh:

- Lng hi cn cung cp, tnh phn cn bng nng lng.

D1 = 200,3888 kg/h

- Chn thit b c s ng n = 187 ng, ng knh ng 20x2mm, xp theo kiu

vng trn.

II.1. H s cp nhit t hi t n thnh ng.

H s cp nhit cho b mt ng ng c xc nh theo cng thc:

1 = 4

1

32

..

....15,1

Ht

gr

, W/m2. (Cng thc V.100, trang 28, [2])

Trong : r: n nhit ha hi, r = 2232,18 kJ/kg ( tnh phn cn bng

nng lng).

Chn t = 2oC.

: Khi lng ring ca nc 110,7oC l 949,975 kg/m3.

H: Chiu cao ng, chn H = 2 m.



: H s dn nhit, hi nc 110,7oC c = 0,684605 W/m..

: nht ca hi nc 110,7oC, = 254,715.10-6 N.s/m2

Vy h s cp nhit:

1 = 21,102142.2.10.254715,0

)684605,0.(81,9.)975,949.(2232180.15,1 4

3

32

(W/m2.)

II.2. H s cp nhit t thnh ng n dung dch nhp liu.

Nhit trung bnh ca dng lnh:

Ti nhit ny ta c cc thng s vt l nh sau:

{

(

)

( )

(

)

(

)

Trong : = 1541,0)405,54(20

004,0157,0 (kcal/m.h.

oC) = 0,1792 W/m.

Tnh chun s Reynold:

( [ ])

+ d - ng knh ng.

+ n - S ng.

lu th

chuyn ng dng.

Ch chy dng, ta p dng cng thc tnh Nu:

(

)

( [ ])

Chun s Pr c xc nh theo cng thc V.35, trg 12, [2]:

Chn (

)

l = 1 (tra bng V.2, trang 15, [2])



Vi: l Kch thc xc nh, l = d = 0,02 m.

H s dn n th tch. Tra bng ti nhit 54,5oC ta c:

=1,1953.10-3.

( ) = 251581,88

Nu = 0,15.1.259,850,33.10,60,43.251581,880,1.1 = 9

Suy ra h s cp nhit t thnh trong ng n dung dch:

( [ ])

( )

II.3. H s truyn nhit.

(

)

II.4. B mt truyn nhit.

( )

II.5. Chiu di thit b.

Chn s ng n = 187 ng.

( )

III. Ni un.

III.1. Chn thit b un si y thp.

Chn thit b un si y thp l ni un Kettle. t ni un ring bit vi thp.

Ni un tip nhn dng lng i ra bn di thp. Nh hi nc bo ha c nhit

cao hn nhit dng lng trn nn s gip ha hi mt phn lng y thp mc

ch to hi cho phn ny c iu kin i ln nh thp.

ng truyn nhit c lm bng thp X18H10T, kch thc ng 32 x 3:

ng knh ngoi: dn = 38 mm = 0,038 m



B dy ng: t = 3 mm = 0,003 m

ng knh trong: dt = 0,032 m

Hi t l hi nc 1,5 at i trong ng 32 x 3. Tra bng 1.251, trang 314,

[1]:

Nhit ha hi: OH2

r = rn = 2232,18 kJ/kg

Nhit si: OH2

t = tn = 110,7 oC

Dng sn phm ti y c nhit :

Trc khi vo ni un (lng): tS1 = 84 oC

Sau khi c un si (hi): tS2 = 97 oC

III.2. iu kin nhit ca qu trnh.

Dng nng : 110,7oC 110,7oC

Dng lnh : 84oC 97oC

Chnh lch nhit u vo : t1 = 110,7 84 = 26,7oC.

Chnh lch nhit u ra : t2 = 110,7 97 = 13,7oC.

= 19,4824oC

III.3. Nhit ti.

QD2 = 1928942,584 kJ/h ( tnh phn cn bng nhit lng).

III.4. Xc nh h s cp nhit ca dng lu cht i ngoi ng.

Xc nh chun s Renold khi hi ngng mt ngoi ng nm ngang:

(Cng thc V.58, trang 28, [2])

nhit 110,7oC ta c:

nht ca nc ngng, (N/m2).

KJ/kg (nhit ha hi)

Sn phm y l nc nn tnh h s cp nhit ta c cng thc:

t: Hiu s nhit . Chn t = 5.

p: p sut tuyt i trn mt thong. p = 1,5at = 147150 N/m2.

III.5. H s cp nhit ca hi t trong ng.

Ti nhit ca dng nng: 110,7oC ta c:



: Khi lng ring ca nc ngng = 949,975 kg/m3

*: Khi lng ring ca hi nc * = 1,11 kg/m3

= 0,0568N/m (Sc cn b mt).

Chun s Nuselt:

(

)

(

)

Chun s Reynolds:

Chn Ksb = 400 (W/m2.)

H s: C = 1,26; l/d = 50 225, chn l/d = 50.

Do ta c:

(

)

H s cp nhit t hi nc n thnh ng:

III.6. Xc nh h s truyn nhit.

( )

III.7. B mt truyn nhit.

III.8. Chiu di thit b.

Chn s ng n = 187 ng.

( )



IV. Thit b lm lnh sn phm nh.

ng i ca dng lu cht: Nc lm ngui i trong ng, sn phm nh i

ngoi ng.

Dng nng: 78oC 35oC

Dng lnh: 45oC 25oC

Chnh lch nhit u vo: tv = 78 45 = 33oC

Chnh lch nhit u ra: tr = 35 25 = 10oC

Chnh lch nhit trung bnh:

Chn ng tiu chun c ng knh l 25 x 2 mm, s ng n = 37.

IV.1. H s cp nhit t dung dch n thnh ng.

Nhit trung bnh ca dng nng: ttb2 = (78 + 35)/2 = 56,5oC.

Ti nhit ny ta c cc thng s dng nng nh sau:

{

H s cp nhit c tnh theo cng thc V.100, trang 28, [2]:

, W/m2.

Trong : r - n nhit ngng, r = 284,6888 kcal/kg = 1191,65 kJ/kg ( tnh

phn tnh ng knh on luyn).

Vy h s dn nhit:

( ) ( )

, W/m2.

IV.2. H s cp nhit t thnh ng n nc.

H s cp nhit tnh theo cng thc V.33, trang 11, [2]:

d

Nu

.2



Nhit trung bnh ca dng lnh: ttb1 = 35oC.

Ti nhit ny ta c cc thng s vt l dng lnh nh sau:

{

Lng nc cn gii nhit: Gn = 991,0912 kg/h. tnh phn cn bng nhit

lng.

d: ng knh ng truyn nhit, chn d = 0,03 m.

Nu: Chun s Nuyxen, c tnh theo V.40 trang 14 S tay QTTB

tp 2.

Nu = 25,043,08,01 )Pr

Pr.(Pr.Re..021,0

t

Vi: Prt: Chun s Prant ca dng tnh theo nhit trung bnh ca

tng.V chnh lch nhit gia tng v dng nh nn 1Pr

ĐỒ Án

Documents