NGHIEN CUU - TRAO 0 0 !
N G H I E N C U f U S U A N H H U O N G C U B M O T S O T H O N G S O C O N G N G H € T C f l H I € U S U f i T I O C B U I T R O B B V T I / K H I T H A I
N H f l M n V N H I € T f ) l € N D O T T H A N C U R L O C B U I T U I
• • • •
(*) TS DT'ONG VAN LONG
KS. H O A N G T R U N G K I E N KS. H O A N G T R U O N G S O N KS T R I N H X U A N D A T
1. D A T V A N D E
Trong nhirng nam gan day. dat nuoc ta dang day manh xay dung cac cong tnnh thuy dien va cac co so ha tang, nham dap ung nhu cau dien nang. nhu cau ve nha o va di lai cua nguoi dan. gop phan phat tnen kinh te xa hoi cua dat nuoc.
De tang hieu qua kinh te du an thong qua viec ap dung cac giai phap ky thuat tien tien trong cong tac xay dung dap thuy dien. nhieu du an tren the gidi va Viet Nam da ap dung cong nghe be tong dam lan (RCC) thay the cho cong nghe be tong thong thudng o cac dap thuy dien cd cong suat trung binh va Ion.
De ap dung duoc cong nghe be tong dam lan. van de quan trong la phai xac dinh dupe nguon cung cap vat lieu ket dinh (Pozzolan) theo 2 huong: Su dung vat lieu Pozzolan tu nhien tu cac mo Pozzolan hien cd (phuong an nay theo danh gia cua cac chuy en gia la kho kha thi o dieu kien Viet Nam): hoac su dung tro bay tu cac nha may nhiet dien (co tinh kha thi cao ve ky thuat. tru luong va dap ung dupe nhu cau su dung trong thoi gian ngan).
Can cu theo cac bao cao Quy hoach phat tnen nguon dien gan day thi. trong giai doan 2006 - 2010.
se khoi cong dua vao van hanh khoang 40 du an thuv dien co quy mo cong suat tu 30 VIW tro len. tong cong suat cac du an nay khoang 4.850 M\V. Cac du an nav du kien su dung 70% be tong dam lan. khoang 12.6 tneu m2. V d i khoi luong be tong dung cong nghe dam lan noi tren. du kien can khoang 1.7-2 tneu t i n phu gia.
Giai doan sau n i m 2010. do so lupng va quy mo cong suat cua du an thuy dien ting len dang ke nen nhu cau phu gia be tong cho cong nghe be tong d i m lan cung ting tuong img. D u kien. binh quan hang ham nhu cau i * i Yien Nghien cuu Ca khi
phu gia cho be tong d i m lan nam trong khoang 2' HI 0l H l - 300.000 tan/nam. D i e biet. doi vol du an Nha may Thuy dien Son La cd cong suit 2.400 MW. khoi lupng be tong d i m lan cin phai su dung la 4.4 tneu nr.
Thay dupe van de do. nhieu doanh nghiep nhu Cao Cuong. Bac Son da khai thac. tai che khi thai tu nha may nhiet dien de thanh tro bay. Nhung khau lpc bui cua cong doan say lua chon cong nghe lpc bui uol nen anh huong nghiem trong den moi truong va lam giam ning suat thiet bi do phai thai nhieu tro bay theo nuoc.
Truoc tinh hinh nay. Vien Nghien cuu Co khi da tham quan. khao sat trong va ngoai nuoc de tim phuong an nghien cuu. tinh toan. thiet ke thiet bi loe bui khi thai bang phuong phap say kho tu may say vat lieu co do am tdi 17% trong cong nghiep
V i cong doan say tro bay co do am d i u vao cao.
trong moi truong nhiet do cao nen khi dua thiet bi loc bui vao hoat dong d i xay ra rat nhieu van de anh huong den hieu suit cua loc bin t u do lam giam nang x u i t cua day chuyen say tro bay
X u i t phat tu nhung dac diem \ a tmh hinh tren tac gia da chon de tai:
"Nghien cuu su anh huong cua mot so thong so cong nghe tdi hieu suit loc bui tro bay tu khi that nha may nhiet dien dot than cua loc bui tui" de cai thien hieu suit loc bui tu do nang cao nang suat cho dav chuy en say tro bay. dem lai hieu qua kinh te.
2. TONG QUAN CAC PHUTJNG PHAP LOC B I T C H O Q U A T R I N H S A Y
V d i cong nghe truyen thong, trong cong doan loc bui cua qua tnnh say cac san pham cd do am cao. a mdi truong nhiet do cao noi chung va say tro bay noi neng thuong dupe su dung phuong phap loc bui uot hoac lpc Xiclon.
2 8 TAP CHI CO KHI VIET NAM • So 11 - Thang 11 nam 2010
NGHIEN CUU - TRAO OOI Su dung phuong phap lpc bin udt: vdi uu diem: chi
phi dau tu thap. de van hanh. dap img dupe nhung dac diem cua qua trinh say ve dp am cao va nhiet do cao.
Nhung phuong an nay co nhung han che:
+ Hieu suat loc bui thap, do qua tnnh tach pha khi ra khoi bin thi bui da bi hoa tan vao nude, khong thu hoi lupng bui dupe. Ma thuc te. lupng bui theo khong khi trong qua trinh say tro bay chiem kha Ion. khoang 25%-30% nang suat tro sau say.
+ Phuong phap nay hieu qua kinh te khong cao. do tieu hao nhieu nude vao qua trinh loc bui. chi phi say lai bun nhao hoac chi phi van chuyen bun nhao do ra bai
Su dung phuong phap lpc Xiclon: trong moi trudng nhiet do va do am cao cua qua trinh say tro bav.
phuong phap nay cung dap iing dupe y eu cau. nhung thuc the ham lupng bui sau lpc khong dat duoc tieu chuan ve moi trudng doi vdi bui khi thai cong nghiep (<140mg/N.m3).
Su dung phuong phap lpc bin tui: V d i kha nang thu hoi dune lupng bui sau lpc de tai su dung de nang cao nang suat day chuyen, tiet kiem chi phi san xuat.
Nhung vdi moi trudng cd do am cao cua qua tnnh sav tro bay (dp am tro dau vao <17%. do am tro thanh pham <2%) va nhiet do cao ( <140°C) la nhung thong so anh huong true tiep den hieu suat lpc cua loc bui tin Vdi lupng hoi nude ldn thoat ra tir qua trinh say.
theo khong khi va bui vao buong l o c o che do chua thich hop, luong nude nay se bam vao be mat tui vai.
gay bet tin lam anh huong qua trinh lpc va hieu suat b e . Nhiet do cao se lam chay tui lam tang nong do bin phat thai ra moi trudng.
3. DAC DIEM QUA TRINH SAY TRO BAY C O D O A M C A O
Trong day chuy en cong nghe say vat lieu co do am cao noi chung va say tro bay noi neng deu co chung mot phuong phap la diing nhiet de tach nuoc ra khoi bpt tro bay, lam giam dp am cua tro bay say den muc can thiet (theo yeu cau la san pham tro thanh pham dat dp am <2%). Tac nhan gay nhiet o day cd the la dot than.
Id dien. gaz . . .
Nguon nhiet trong say tro bay diing Id dot than.
ngudi ta su dung 2 phuong an:
+ Phuong an say tiep xiic (hinh 1). tire la be mat gia nhiet la thiing say. tiep xuc true tiep vdi vat lieu say:
1 liiih 1: Anh may say tiep xiic + Phuong an say doi luu (hinh 2): Diing luong gid nong lay tir Id dot than thoi vao buong tang say:
•b=o=<y I linh 2 Su do say doi liru trong day chuyen say tro bay Pha Lai
1.L6 dot than 2 Tang sav 3 Vit thu hoi heu 4 Loc bui Dac diem cua qua trinh say tro bay sau:
+ Voi y eu can do am cua tro bav thanh pham < 2% trong khi do am nguyen lieu tro bav dau vao lai cao (17%);
+ Mat khac. dac diem cua bot tro bay la sieu mm. cd hat < 20 m. do do. luong bin tro bav vao thiet bi loc bui
la rat Ion. khoang 30% khoi lupng tro bay dau vao may say. cd the gay qua tai cho thiet bi loc bui. gay kho khan cho viec lam kin tai nhung vi tn can ngan bin.:
TAP CHI CQ KHI VIET NAM • > So 11 - Thang 11 nam 2010 2 9
NGHIEN CUU • TRAO OOi
- Kha nang hap thu nhiet cua tro bay ru qua tnnh say. cung v oi luoms 210 none luu thorns tu buons sav thoi
\ ao lam cho nhiet do trong buong loc bui tang, tren thuc te nhiet do irons, buons loc bui co the len den 161H >C;
- Thanh phan tro bay bao gom:
Bang 1 Thanh phan cua tro bay
Thanh p h i n hoa hoc S i 02 A2O3 FezQs CaO N a20
% trpng hicmg 53.2 24.2 6.38 2.17 0.44
Vdi thanh phan neu tren. hot tro bay co unh mat mon rat cao. gay rat nhieu kho khan cho cac thiet bi ehu\en dong trong day chuyen say
4. N G H I E N C U T A N H H U O N G C U A M O T SO T H O N G SO C O N G N G H E C U A L O C B U I T U I L O C B I T T R O B A Y T U K H I T H A I C U A N H A M A Y N H I E T B I E N D O T T H A N B A N G T H U C N G H I E M
Dau nam 2008. Men Nghien cuu Co khi da nghien cuu thiet ke. dua vao van hanh he thong say - loc bui- dong bao cho day chuyen san xuat no bay tai Pha Lai.
thudc Ban Quan ly Du an Thuy dien Son La Nhung.
do dac thu khac nghiet cua xro bay (cd hat sieu mm. eo tinh mai mon cao. hoi nuoc thoat ra trong qua trinh say nhieu. mdi truong nhiet do cao). da gay ra nhung anh huong khong nho den nang suat va hoat dong on dinh cua cac thiet bi trong day chuy en Thay duoc nhung
\an de day. cuoi nam 2009. nhom de tai da tien hanh nghien cuu bang thuc nghiem de tun ra bo thong so toi uu cho qua tnnh loc bui tai co so say no bav nav.
4.1. Tin nghiem anh huong chu ky ru bui den hieu suat cua lpc bui
Thuc hien thi nghiem nay. ta co chnh cac thong so dau vao khac nhu:
- Nhiet do trong buong loc 150 C
- Luu luong gio hut: 24.000 r n: h - 26.000 m? h Bang 4 1 Bang do ket qua nong do bui khi thai doi chu k\
ru but
n - - m . 1 - L None do bui
11 L hu kv ru bui - . . Ghi chu 1 ' 60 2 6 "
3 5 90 4 4 95 5 3 120
Hinh 4.1: Quan he chu ky ru bui va nong do bui tai khoang khi sach 4.2. Thi nghiem anh huong cua chu ky ru bui den cudng do dong dien qua dong co quat hut
De nhiet do buong say on dinh 650-"00 C. luu
luong quat hut de on dinh 0 muc 24. 000 m: h - 26. 000 m" h Chu ky ru bin ta thay doi giam dan. thu tu n giay .
n riav. 5 siav. 4 siav. 5 eiav.
Bang 4.2: Quan he giua chu ky ru but va dong dien qua dong co quat hut
gian
Tan so ru bui
Cuong do dong dien qua dong co quat hut IA1
Ham luong but sau loc
(mg y.nr /
1 08h50 - ^ 108 60
2 Uh50 6 gun 110 75
3 14h50 5 giay 111 90
4 L7h50 4 giay 11? 9 5
5 2Oh 10 5 giay 115 120
E 3 TAP CHI'CQ KHI VIET NAM •> So 11 -Thang 11 nam2010
NGHIEN CUU - TRAO DOI
~jbng 46 dong dien (A) 116
114 112 110 108 106 104 0
^ 1 •
- — -
Chu ky rii bui ( giay ) Hinh 4.2: Quan he chu ky ru bin va dong dien qua
dong co quat hut 4.3.Thi nghiem anh huong ciia luu luong quat hut den hieu suat ciia loc bui
Thuc hien thi nghiem nay. ta co djnh cac thong so dau vao khac nhu:
+ Nhiet do trong buong loc: 1300C + Chu ky ru bui: 3 giay
Thav doi luu luong quat hut
Bang 4.3: Bang do ket qua nong do bui khi thav doi luu luong quat hut
TT Luu lirong quat hut (mVh)
Nong do bui
(mg/N.m*) Ghi chu l 16. 000 - 18. 000 65
2 20.000 - 22. 000 72 J 24. 000 -26. 000 90 4 28. 000 - 30.000 140 Nong <5t> bui ( mg/N m )
140 120 1 00 80 60 40 20 0
/ / / A c i t - — ^ V
b ro O O o
u o o
ro CO o o o
o o o o
- 18000 22 000 26 000 30 000
Luu luong gio quat hut ( m Ik ) 1 linh 4 3 Quan he Urn luong gio quat hut va none do bui
5. K E T L U A N :
Bang thuc nghiem budc dau. da xac dinh duoc bo thong so cong nghe thich hop de dat nang suat he sav - loc bui tui 7.5 tan/h vdi do am tro ra < 2 V
Bo thong so:
+ Nhiet do vao mav sav tmng binh 650'C - 7 0 0 T ;
+ Nhiet do tmng binh trong mav say: 675"C ; + Do am tro dau vao trung binh: 17% ;
+ Nhiet do khong khi vao lpc bui (120"C - 140°C):
+ Ap suat khi nen ru bui: 4-6 kg/cnr : + Tan so rii bin: 3 giay ;
+ Luong gid quat hut trung binh: 24.000mVh - 26.00()m7h ;
+ Ham luong bui sau loc dat T C V N ve moi trudng:
< 150mmg /N.m-
B6 thong so tim duoc sau qua trinh thi nghiem cua de tai da dupe Co so tro bay Pha Lai nghiem thu va dua vao ung dung trong san xuat, budc dau cho ket qua rat tot. tang hieu suat loc bui. nong do bui sau lpc dat dupe T C V N ve moi trudng va dupe Cue Do ludng Tieu chuan 1 do dac va chung nhan.
T a i lieu t h a m k h a o :
[1] Hoang Kim Ca, Ky thuat loc but va lam sach khi. NXB Giao due Ha Noi, 1999.
[2] Tran Ngoc Chan. O nhiem khong khi va xu ly khi thai (Tap 1,2,3), NXB Khoa hoc va Ky thuat. Ha Noi. 2001
[3] Tran Ngoc Chan, Ky thuat thong gio. NXB Xay dung. Ha Noi, 1998
(4) Duong Dire Hong - Pham Van Tri, Ky thuat lpc bui trong cong nghiep. NXB Khoa hoe va Ky thuat. Ha Npi. 1989
[5] Doan Tai Ngp (chu bien). May san xuat vat lieu va cau kien xay dung. NXB Xay dung. Ha Npi, 2000
[6] Tran Xoa, Nguyen Trong Khuong. Ho Le Vien. So tav qua trinh va thiet bi cong nghe, hoa chat (Tap 1). NXB Khoa hoc va Ky thuat. Ha Noi, 2005.
[7| Tran Van Phu. Tinh toan va thiet ke he thong sav
[8]. INTENSIV FILTER. Operating instructions for Intense - Slee\ es- Senes Filter. Combi-Jet, Type: IF JC C 85 8-4
[9] STANDARD FILTER CORPORATION, TubeJetR Dust Collector Application Guide; www.standardfilter.com
110] F.L SMIDTH FiltaxR Jet Pulse filter [11]. Pipe Flow Wizard, www Pipeflow.co uk
TAP CHI CQ KHI VIET NAM • So 11 - Thang 11 nam 2010 3 1
