Mô hình vật lý mô tả sự ảnh hưởng của các yếu tố độc lập tới hiệu suất của quá trình hấp thụ khí SO2 trên thiết bị xử lý khí phát sinh từ lò đốt chất thải rắn nguy hại

MO HINH VAT LY MO TA SU ANH HlTdNG CUA CAC YEU TO DOC LAP T 6 I HIEU SUAT CUA QUA TRINH HAP THU KHI SO2 TREN THIET BI XU LY KHI PHAT SINH T f LO DOT CHAT THAI RAN NGUY HAI THE PHYSICAL M

MO HINH VAT LY MO TA SU ANH HlTdNG CUA CAC YEU TO DOC LAP T 6 I HIEU SUAT CUA QUA TRINH HAP THU KHI SO2 TREN THIET BI XU LY KHI

PHAT SINH T f LO DOT CHAT THAI RAN NGUY HAI

THE PHYSICAL MODEL FOR DESCRIBING THE INFLUENCE OF INDEPENDENT

PARAMETERS ON THE YIELD OF SO2 ABSORPTION FROM THE NOXIOUS SOLID WASTE

INCINERATORS

Pham Thj Thu Hoai Nguyin Bin

Trucmg Dai hoc Kinh te - Ky thudt Cdng nghiep Trudng Dgi hoc Bdch khoa Hd Ndi

Din Toa soan 13-8-2013, chdp nhan ddng 25-12-2013

TOM T A T

Qua trinh hap thu SO? bing dung dich Ca(0H)2 la gua trinh hap thu hda hoc di thi giira pha khi

va pha Idng Phan irng xay ra trong viing khuech tan vi ddng hoc phan wng trung hda nay xay ra vdi toe dd rit nhanh, vi vay di md ta rd han ve qua trinh ta ed thi sir dung cac mo hinh vat ly Qua dd ed the lam rd anh hwang eiia cac yeu to dgc lap Ien cae ham muc ti eu nhw nang suit khi dwgc hap thg,

he s6 cap khoi hieu suit qua trinh hap thu Tir do co the tinh toan thiit ki cac he thong hip thu cd quy md nhd han hay lan han toi da 10 lin Day ia mgt phwang phap chuyin quy md hiru higu cho cac

he cdng nghe thwc hi§n cac qua tnnh chuyen vgt ly Trong pham vi bai bao nay nghien ciru mo hinh vat

ly md ta sw anh hwang cua eae yeu to ddc l$p tdi higu suat ciia qua trinh hip thu khi SO2

Tie khoa: Hieu suat h^p thg SOs; yeu to dgc ISp; venturi

ABSTRACT

SO2 absorption process by Ca(0H)2 solution is the heterogenous chemical absorbtion between gas and liquid phase The reaction occurs in the diffusion area and reaction rate of neutralization is very fast in kinetic term For this reason the physical models can be used to describe more clearly the process These model can demonstrate the influence of independent parameters on the objective function by the absorbed gas productivity, block-level coefficients, the absorption yield Those are the base for scale-up scale-down the absoqjtion process, that can be maximal 10 time smaller or lager This Within the scope of the adicle, the studying of the physical models describes the influence of independent parameters on the yield of SO2 absorbed process

I MO'DAU cdn thilt lap md hinh vdt ly mo ta qud trinh ndy Hien nay Id dot hai buong lo^i tinb dugc [1L[5]

sudung khd pho biln a Viet Nam de xu ly chat 2 MO HINH VAT LY MO TA QUA TKINH thai rdn nguy hai, Khi SO2 Id khi co nong do cao HAP THU SO2

2.1 Xac djnh cdc yeu td dnh huong l€n qud trinh hap thu hoa hgc

nhat phat sinh trong qua trinh d6t, Phuang phap

hap thu su dung dung moi la sua v6i vd thill bi

hdp thu Venturi - thap dem da dugc su dung dl

xir ly lugng SO2 nay Qua qua trinh thuc nghiem S6 cac ylu td anh hudng dgc lap Ien qud

va su dung phuang phdp quy hoach thuc nghiem trinh hap thu hod hgc chinh la bac tu do ciia qua

dd xac dinh dugc ham todn thdng ke mo ta mii trinh dugc tinh theo cong thdc:

quan hi giira hieu suat xir ly vd cdc thdng sd anh c - c J c J c /-> w , • f ,, • u •• J- L •• •• , F-FDK + FNT + FHU (2-1)

huang, day la co so cho viec danh gia chinh xac

muc do anh huong cua cac thdng sd tdi qua Irinh Vdi: FRK la bac tu do dilu khien (s6 cdc

xu l\' SO2 tir dd dd lim ra dugc cac thdng sd t6i yeu td tdi da ma ta cd the thay ddi de dieu khien

im cua qua trinh Tuy nhien dl ldm rd ban anh qua trinh trong he); F\T la bdc tu do ngi tai (cac hudng cua cac ylu td doc ldp tdi hi?u sudt ciia yeu to biln ddi ngi tai trong he); FHH la bdc tu do qud Irinh hdp thu d nhiJng quy mo khac nhau ta hinh hgc

Qua trinh hdp thu hda hgc trong he la qud - D6ng luc chuyen cdu tu bj hap thu Ayib, kg/m-trinh tilp xiic hai pha bao gdm cac phdn tir n6i

tilp nen bac tu do dilu khien la:

- Ddng luc chuyen van tdc, Avib, m/s

2 1.3 Xdc djnh bdc lu da hinh hgc ctia qud trinh hdp th\i hoa hgc SO2

Trong do: ij) la he sd pha, (ji = 2 ; k la sd cdu tu Bgc tij do hinh hgc cua he thuc hien qua quy udc trong pha, k = 2 trinh hdp thu tinh theo cdng thuc:

Nhu vdy: FDK = 2 (2+2) - 8 Cdc ylu td tham f^^ ^ ^^^^^^, + f^^^ (2-4)

gia vao bdc tu do dieu khien la:

; , , „ FHHV - bac tu do hinh hoc cua thiet bi venturi,

- Luu lugng dung dich long hap thu vao OL, p = 5.' '

kg/s;

, - , • , , ,- I , FHHI - Bactu do hinh hoc ciiaThdp, FnHT=4;

- Nong dg chat hap thu trong dung dich long vao • •

XL, kg/m' Nhu vay: FHH = 6 + 4 = 10

- Khdi luang rieng dung dich long vao pu kg/m^ Cac d^i lugng tham gia vao bdc tu do hinh bgc

la:

- Nhiel do dung djch long vao TL, K

- Luu lugng khi vao GK , kg/s

- Nong do chdt bj hdp thu (SO2) trong khi vao,yv

, kg/m^;

- Nhiet do khi vao Tf , K;

- Khoi lugng rilng khi vao PK, kg/m'

2.1.2 Xdc dinh hgc lu do ndi lgi

Bdc tu do ndi tai ciia qua trinh hdp thu h6a

hgc dugc tinh theo cdng thirc:

fNi=P, + Fc (2-3)

Vi: bac tu do ciia ddng ddn

Fd = <t)(k+2) (2-3a)

I- Ddi vdi dng Venturi:

Hinh 2.1 - Ong Venturi

- Dudng kinh mieng vdo dv, m;

- Dudng kinh mieng ra dr, m;

- Dudng kinh eo that d, m;

- Chieu ddi true tu mieng vao din mieng ra I, m;

^ , , , - Chieu dai true tu mieng vdo den mieng eo thdt

Fc: bac tu do cua dong cap p^,^ ^ ^ 1^^ ^

Fc = (4»-l)(ko+2) (2-3b) - Chilu dai true doan eo thdt U,

kc :sd cau tu chuyin k^ = I; <!>: sd pha it> ^ 2; ^ jj^j ^^j ^,^^p

k la sd cau tir quy udc trong pha k = 2

Nhu vdy: FNT = 2(2+2) + (2-I)(2+l) = 11 Cac

yeu td tham gia vao bdc tu do ndi tai Id:

- HI sd dan khdi ciia chdt Idng DL va ciia cdc

cdu lu bi hdp thu (SO2) trong chat Idng DL, , m Vs;

- Dudng kinh thap dt, m;

- Chilu cao Idp dem trong thap h, m;

- B I mat tilp xuc pha rieng cua vat lieu dim E mVm';

- Phan the tich tu do dem Vo, m'/ m^;

- He so dan khoi ciia khi Dk vacua cau tir bj hap

thu (SO2) trong khi DK, , mVs; 2,1.4 Sd cdc yiu Id dnh hudng ddc lap:

- He s6 ddn nhiet dd cua khi akva ciia Idng a^ Sd cac ylu td anh hudng dgc lap dugc tinh

mVs ; theo cdng thuc (2-1) la:

- Do nhdt ddng hgc cua khi v^ vd cua long v, F = 8+ 11 +10 = 29

Dai lugng muc tilu ma ta cdn xet la mgt

trong cdc y l u td sau:

- Luu lugng cdu t u bj hdp thu 0 , kg/h;

- Hieu sudt hdp thu i] |;2],[3]

2.2 Xac dinh cac chuSn so d o n g d a n g v^ thiet

lap md hinh valt ly md ta q u a t r i n h voi h a m

muc tieu la hteu suit h a p thu T\:

Tdng sd cac yeu td la: F + I = 29 + 1 =^ 30

Dai lugng muc tilu la h i l u suat ciia qud trinh hdp

thuri

2.2.1 Cdc chudn sd dan gidn

Ur.'K: n,„

a

• ' PK

A

n, =^;

"K

n „ = ^ ; n

<L n ^ n

-d -d -d

d d d

PK PK

u, =^; n„ ^ ^

T^K fK

A ' "K

V,

Ta xda cac dai lugng Vo',d^ -,d^ ;t/^ ;/ ;/, ; ^

;/) id, ;G, iGipiy, ; ? ; ; D,, ; D,^ ; D^- ;D^.,;

o^ ;ay ',AC,f, ;AT,f, iv, ra khdi khdng gian biln

con lai

2 2 2 Thdng ke cdc dgi lugng con lai:

- Liru luang khi vdo Gk, kg/s;

- Nhiet do khi vao T^, K

- Khoi lugng rieng khi vao PK, kg/m^;

- Do nhdt dgng hgc ciia khi i'^ , m^/s;

- Dong luc c h u y i n dong luong ciia khi A(pKVib),

^ g •

m'.s

- D u d n g kinh eo that d, ( m ) ;

- B l mat tiep xuc pha rieng cua d i m a, m'/m^; Vdy tdng sd cac dai lugng cdn lai Id n" = 7

* Thir nguyln cua cdc dai lugng cdn lai la:

[GK]= kg^s-' - M ' T - - ' ; [TK ] = / C ' = ^ ' , [pK ] = Kg^m-^=M'r^ • [v^] ^m\s~' = L\T-' •

[A(pKV,b)] = kg.m-\s-' = M\L-\T'^ ; [d] = m ' =

L ' ; [ a ] = m " ' = / - '

So thd nguyen c o ban la r = 4

* Ma Iran thu nguyln a,p ciia cdc daii lugng cdn lai vdi i = 1,7 v d p = l,4 cho d bang I Hang cua ma tran thu nguyen a,p la r' = 4, nhu vay sd chudn sd phuc hgp la:

_ r' - 7 - = 3 tuc Idj = H,3

2.2 3 Thiel lap he phuang trinh thir nguyen

Thilt lap he phuang trinh thd nguyen (a.p) (k,j )

= 0 vdi i = l,w' = l,7 v a p = - 1 , 4

Otjj -2k2j +2kjj +\k.^j+2k^j - 3 ^ ^ , +0*^^ ^ 0

-^k^^-\k2J +0^3^ +0^4^ - U j , +0jt6, +Ok^j =0

lytij + 1^3j + 0^3^ + Ok^j + Ok^j +1^6, + 0*7; = 0

(2-5)

OAij + 0^,^ + 0^3^ + Ok^j + 0^5^ + 0^6; + 1 *7 , = 0

+ Gidi h i k h i j = 1 chgn cac nghiem l i r d o k n = 1 ; kji = k3i = 0 t a c d k i t qua sau:

Bdng 1

p ^ ^ ^

1

1

3

L

T

M

1

X I - G K

0

-1

1

2

X 2 - A ( p K V | b )

-2 -1

1

3

X3 = a

-1

0

0

4

X 4 - d

1

0

0

5

X 5 = Vf

2 -1

0

6

X < = P K

-3

0

1

7

X 7 = T K

0

0

0

Ar,| = 0 ; A - , i - l ;i(:5| = 1 ; * ^

Nhu vdy :

+ Cdc chuan sd dan gidn :

n.=n,=;;;n,=5L=n„,;a=^=n„

n„=-n„ =

A,

n„ ,;n n.,.,

=n, ;n„=^=n„;n,3=-^=ni', f«: /'it / " j

d ' d d

n2z=^-n,,;n„=^-n/.;n24-^=n<

+ Giai he khi j ^ 2, chgn cdc nghiem tu do

*22 - *''^i2 - '^32 = 0 ta cd ket qua sau:

/:,j=0 ; * 6 2 - - l ; A 5 3 = - l ; i 4 2 - l

Nhu vay

rr 0 I 0 I -I -1 0 dMPiV,h)

11, = ;Ci ,;c2 ,X; x^ JC, X^ X, ^

Pk-^'k + Gidi he khi j = 3 chgn cdc nghiem tu do

*33 = h*:3 - *^o - 0 ta cd ket qua sau:

i ^ 3 = 0 ; * s 3 - 0 ;A53 = 0 ik.^^ + l

Nhuv^y Yli -x°.x°.xl.x'^ x^.x^.Xy =ad

2.2.5 Thiet ldp mo hinh vdl ly md Id quan be 2.2.4 Thdng ke cdc chudn sd vd md td suphii^ gjCra hieu sudt hdp thu vd cdc yiu Id cong nghe thudc giira bieu sudt hdp thu SO2 vdo cdc yeu td dgc lap

dnh hudng ddc ldp , , , , , ^ „ ,, x ,

• _ Mo hinh vgt ly nay co dang (2-6) Neu he + Cdc chudn sd phdc hgp: sd thuc hiln qud trinh khdng thay d6i vl nhiet do

^ /VACn ^ va dong dang hinh hoc thi mo hinh vdt ly thu ve

n i = : f ^ ; n = ' ^ " ' ^ n , = o d dang(2-6a)

"^'KPK PK''K G J A >'« "k- ''r

( f t , , (i?L,.i ( ^ ) ( A , , , ( i , ^y^y., ( ^ ) ( ^ , ,

IK

a

PK PK PK

(2-6)

(i, (i) 4 r (1,.-, (i, , (i)., Ar" A '

nr-Tf d d d d d d d

O^KPK ^KPK O, D J V„ VJ VJ

(itr (fL,-„-(il,, (PL, ,i, (i^_,.,(^,

'•*• ''K "A- /'f / ' j A PK

Vai qua trinh hap thu a day c6 the coi la

dang nhiet vi dung iTioi sg bay hai belt de t = const

Vi vay he duoc dieu lihien bcri dai luo'ng nhu iiai

luong khi, Itru luong long, nong do long, khi

do mo hinh thu gon ve dang:

n„=')=c;(-d^KPK (^Y>,^

(2-6a)

r'(7+r'{^r"(2-6b)

6 dang m6 hinh (2-6b, ta quan tam t6i anh huong ciia ch^ do thuy dong anh huong cua liai luong pha long, anh hirong cua nSng dp pha long

Bdng 2

i

1

2

3

4

1

0,922

0,911

0,9056

0,87

GK, kg/s 1.24 1,39 0,972 0,555

OL, kg/s 2,74.10"' 2,77.10"' 1,81.10"' 0,83.10"'

XL,kg/m'

70

70 74,3

30

pK,kg/m' 0,757 0,757 0,757 0,757

i-j , m 7 s 3,21.10"' 3,21.10"' 3,21.10"' 3,21.10"'

d, m 0,254 0,254 0,254 0,254

i

1

2

3

4

n,=^

0,922

0,911

0,9056

0,87

•I^KPK

200903,3 225206,1 157482,3 89920,4

'^K

0,00221 0,00199 0,00186 0,0015

PK

92,47 92,47 98,15 39,63

2 2 6 Xdc djnh cdc tham sd cita md hinh vdt ly

Cdc tham sd ciia md hinb (2-6b) la

C\-,af-,a'^;a^i, chung se dugc xdc dinh nhd cac

sd lieu gan gia tri iimax cho d bang 2 khi nhiet do

khi la 200''C va dp sudt khi bdng latm, Cac gia

trj tuong dng ciia cdc chudn so cho k i t qua d

bang 3

Thiet lap he p h u a n g trinh xdc djnh tham so:

gn„,=igc;+a;ign„+«5ign5,+ai4ign,4,;V(=M

Thay s6 vd thuc hien phep logarit ta co he

- 0 , 0 3 5 3 = lgC4+5,303a,'-2.656Qr5+l,966Qr|4

- 0 , 0 4 0 5 - I g Q + 5,353a; - 2 , 7 0 1 « ; +l,966Qf;4

(2-7)

-0,0431 = lgC4 +5,197a|' - 2 , 7 3 0 « 5 +1.992a|'4

- 0 , 0 6 0 5 = lgC4 + 4 , 9 5 4 a | - 2 , 8 2 4 ^ 5 +1.598a|4

Gidi he phuang trinh (2-7) bdng phdn m i m

a | - - 0 , 0 0 1 5 ; a 5 = 0 , 0 1 7 9 ;

M a t l a b l a c d

a , 4 - 0 , 1 1 4 ; C 4 = 1,271

Thay vao (2-6b) ta co md hinh vdt ly eu t h i mo

ta s u phu Ihugc ciia h i l u sudt hdp thu khi SO2 vao

n 7 ; ^ i , 2 7 i ( - ^ ^ ) ' * - ' ' » ' ^ ( - ^ ) ' ' - ' " ' ^ ^ ) ' ' ' " ^

^''KPK GK PK

(2-6c)

3 K E T LUAN Cdn c u vao mo hinh vat ly (2-6c) ta thdy:

- Hieu sudt hdp thu ty le nghich vdi chudn so Reynolds (Re^ = — ) vdi h i so

dpi-.Vf

ty II rdt be ( a , - 0,0015 ) Nhu vay ta co the thdy rdng che do thiiy dgng dnh hudng khong ddng ke

d i n s u biln ddi ciia hieu suat hap thu d vimg tdi uu;

- Hieu suat hap thu phu thugc ty II ihuan vdo ty le giua luu luang long vd luu lugng khi vdi he so ty le da ldn han nhung cung khong phai

I a r d t d a n g k i ( t t 5 = 0 , 0 1 7 9 ) ;

- Hieu sudt hdp thu phu thugc ly II thuan vdi chuan sd ddc trung cho nong do pha long, nhung vdi sd mu be 0:,^ = 0,114

TAI LI?U THAM KHAO

1 Pham Thi Thu Hoai, Nguyln Bin (2013) - Tdi uu hda qud trinh xu ly SO2 trong khi thdi phat sinh ttr

16 d6t chdt thai rdn nguy bai bdng phuang phap quy ho^ch thuc nghiem - Tap chi Khoa hgc va C6ng nghe cdc Trudng Dai hgc ky thuat sd 92, 152-156

2 Pham Thi Thu Hoai (2013)-Sudnh hudng ciia cdc ylu td dgc ldp tdi luu luong khi SO2 bi hdp thu tren thiit bi xu ly khi phat sinh tu 16 dot chat thai ran nguy hai - Tap chi" Hda hgc vd dng dung" so 6/2013,1-4

3 Nguyln Minh Tuyen Md hinh hda va toi uu hda qua trinh cong nghe hda hgc Dai hgc Bdch Khoa

Ha Noi, 1981

4 Nguyln Minh Tuyen, Pham Van Thiem Ky thuat he thdng c6ng nghe boa hoc, t^p I: Cosdmo hinh hda qua trinh cong nghe hoa hgc, NXB Khoa hgc vd Ky thudt Ha Ngi (2005)

5 Hiderahu Yagi, Koyosuke Okamoto, Keiji Naka and Haruo Hikita, Chemical absorption of COi and SOi into Ca(0H)2 slurry, chem Eng.Commun Vol 26,1984,1 - 9

Pham Thj Thu Hoai - Tel: 0947485555, Email: ptthoai@uneti edu.vn Trudng Dai hgc Kinh tl - Ky thuat Cong nghiep

456 Minh Khai, Hai Ba Trung, Ha Ngi