Lua ehoii h e son phu hmi e<y eho bon ehna v a thiet bi trao doi nhiet
KS. Nguyin Dac Thing ThS. Le Quang Hung ThS. Nguyen Quynh Anh Vien Diu khi Viet Nam
1. Ma dau
Viet Nam nam trong vung khi hau nhiet d&i nong am, tfep giap v&i biin nen ton that do an mon va ton thit xang diu bay hai do bii'c xa mat tr&i gay ra la rit l&n. Cac he thong bon, be chiea trong cac cong trinh diu khi (nha may Igc - hda diu, khi, dien, dam....) trong nw&c hien nay chii yeu dwgc che tao tie kim loai cho nen kha nang hip thu nhiet la rit cao. Cac he thong thiet bj nay lam viec trong moi trw&ng di bj an mon va tiep xiic trwc tiep v&i anh ning mat tr&i. Hien nay, phwo'ng phap bao ve pho bien, hieu qua nhat la dimg l&p phu bao ve. Do vay, viec Iwa chgn loaf so'n phu bao ve chong an mon dong th&i han che kha nang truyen nhiet vao ben trong cac bon, bi chO'a / 4n thiet.
Cac thfet bi trao doi nhiet (TBTDN) trong cac nha may, cong trk:y diu khf co rat nhieu loai va thw&ng lam viec trong dieu Men nhiet do, ap suit cao. - .-.. g^/^^p ^ ^ ^ ^g chong an mon cho cac thiet bj nay rit da dang. Thong thw&ng doi v&i n, , if fyj ^^gg doi nhiet lam viec & nhiet do, ap suit cao (khoang tu' lOOOC tr& len nhw. v, ^iy^ co dac... [1]) thi l&p phu bao ve ben ngoai thanh thiet bf thw&ng su' dung nh ^ 'pfj^
1/2.010
dac biet chuyen dung va thw&ng la nhQ'ng l&p phu vo co- co kha nang chju dwgc nhiet do cao [2].
Dof v&f nhieng thfet bf trao dof nhiet lam viec trong dieu kien nhiet do khong cao (thip han lOQOC nhw: Thfet bf lam mat, ngwng tu... [1]) thw&ng chi su' dung nhieng l&p phu bao ve la nhwng he san hu'u ca thong thw&ng [3], [4]. Do do, viec Iwa chgn nhu'ng he san phu bao ve hgp ly se nang cao dwgc hieu qua sie dung cua cac he san.
Chung toi tap trung vao viec nghien cwu Iwa chgn nhQ'ng he san phu hieu ca cho he thong cac bon be chiea va cac thiet bi trao doi nhiet lam viec trong dieu kien nhiet do thip han lOO^C nham nang cao hieu qua sie dung cua cac he san phu hieu ca va khuyen cao cac nha sii' dung khi Iwa chgn he san phu cho cac doi twg'ng khac nhau.
1.1. San chong an mon, tan nhiet cho bon be chiea va TBTDN Nhu da bilt, son chdng an mdn (hay tren thj trudng ggi la son chong gi) la loai son da trd nen pho bien. Thdng thudng cac hang thudng san xuat son chong an mdn la son epoxy giau kem. Bdi vi son tren co sd nhua epoxy ed nhung dac tinh quan trgng thich hgp cho mang son nhu kha nang chju hda chit, do m I m deo, bam dinh tot, chju nhiet do va cd do cung cao... Oae biet khi k i t hgp vdi k§m, kim loai dung trude sat trong bang tuan hoan hoa hgc, hy sinh (chju an mdn) trudc sat thep.
Odi vdi nhOng mdi trudng nhiet ddi ndng am ed kha nang gay an mdn eao vol sat thep thi he son phu thudng SLP dung them Idp trung gian thu 2 la Idp epoxy cd chua vay mica oxit sat. Vay mica oxit s i t nay eung giong nhu mdt buc tudng rao, chju an mdn trudc b l mat thep dugc bao ve [5].
Hieu qua bao ve eua son chdng an mdn dugc md ta theo Hinh 1.
Hinh 1. Md ta hieu qua bao ve kim Ioal khi bi mat kim loai dwgc san bing lap san chong an mdn
Son tan nhiet la loai son dugc s u dung vdi muc dfeh tan nhiet nen thanh p h i n bdt mau r i t quan trgng, cd tae dung phan xa cac buc xa nhiet t i l p xuc vdi be mat vat lieu, khiln cho nang lugng cua buc xa nhiet chi h i p phu mdt p h i n len vat lieu, tranh s u tang nhiet do khdng mong muon.
Cae he son tan nhiet thudng s u dung vdi Idp son ngoai eung la polyurethan vi son tren co sd nhua polyurethan cd cac dae tinh r i t tdt nhu: Bdng, dep, cung, dan hoi, chju ma sat, va dap, b i n hda c h i t va dac biet tfnh b i n thdi t i l t la tinh c h i t noi trgi n h i t trong cae loai son. Son tan nhiet chu y l u d i u cd mau trang do dugc trdn vdi bdt Ti02 mau tring cd tac dung phan quang, chdng h i p thu nhiet. Ldp son tan nhiet dugc SLP dung lam Idp ngoai cung trong mdt he son. Hieu qua bao ve cua son tan nhiet dugc md ta nhu Hinh 2 [4].
(a) K i m loai khong son (b) K i m loai duac son (c) K i m loai dugc son tan nhiet Hinh 2. Md ta hieu qua bao ve khi dung san tan nhiet
Dfiu K H i - s o 11/2010 4 7
1.2. Mgt so tieu chf de Iwa chgn he san phu phu hg'p v&i bon be chiea va TBTDN nhw sau:
- He son dugc lua chgn phai la he son cd dae tinh eo ly tdt nhu kha nang chju mai mdn, dp bam dinh, do bdng, do cung tdt.
- Cd kha nang chdng an mdn tdt vi mdi trudng khi hau Viet Nam la mdi trudng nhiet ddi ndng I m , de gay an mdn cao vdi kim loai.
- Cd kha nang chju hoa chit, chju xang d i u vi mdi trudng d i u khi la mdi trudng cd nhilu san p h i m nay.
- Cd kha nang b i n vdi tia t u ngoai, b i n thdi t i l t vi cae thilt bj h l u h i t duge xay dung ngoai trdi.
- Cac he son s u dung cho bdn, be ehua c i n cd kha nang each nhiet tdt vi khi cd anh hudng cua nhiet ben ngoai (buc xa mat trdi) d l lam eho nhiet do ben trong tang cao, lam bay hoi cac san pham ehua ben trong eae bdn, b l chua.
- o i l vdi loai TBTON can tda nhiet nhanh ra ngoai mdi trudng nhu cac thilt bj ngung tu, t h i l t bj lam mat... thi he son bao ve c i n ed tfnh nang tan nhiet nhanh, b i n nhiet, b i n sdc nhiet
1.3. Tinh hinh thj trw&ng san chong an mon, tan nhiet cho bon be chO'a va thiet bi trao doi nhiet
Cy nude ta hien nay mac du son phu da phat trien r i t manh me va dugc tin dung, tuy nhien chi cd mgt sd r i t it nha cung cap son cdng nghiep eho bdn, be ehua va thilt bj trong do h l u h i t d i u cung d p son nhap t u nudc ngoai nhu Jotun Paint Ltd., International Paint Pte. Ltd., Son Hai Phdng, Son Ha Ngi... Cac he son nay co ban d i u cd tinh nang chong an mdn, tan nhiet.
Theo eae nha cung e l p va nha san xult, de ddng thdi cd tac dung ehdng an mdn va tan nhiet c i n son 2 hoae 3 Idp son tuy thanh p h i n son va tuy nha eung d p .
Bang 1. Mdt so hang san ehuyen san xuit san edng nghiep tren thi glal va a Viet Nam
Cong ty Ceram-Kote (0i>c) Jotun Paint Ltd (Na Uy) International Paint R e . Ltd(Anh) Son Hai Phong (Viet Nam) Son Ha Noi (Viet Nam) Son A Dong (Viet Nam)
San pham He son Ceram-Kote He son EPU TDS He son Epoxy PUX He son HEPU Trang He son D-Pol He son Aep
Dua vao cae tieu chf dat ra va tim hieu thuc te tren thi trudng son phu cong nghiep d Viet Nam, chung tdi
lua chgn 4 he son de thu nghiem danh gia cung nhi^
so sanh s u phu hgp eua tung he son nay vdi tung d i l u kien lam viec cua thilt bj trong dieu kien moi trudng khi hau Viet Nam:
+ He son D-Pol (Cdng ty Son Ha Ngi).
+ He son HEPU Trang (Cdng ty Son Hai Phdng).
+ He son EPU TDS (Jotun Paint Ltd.).
+ He son Epoxy PUX (International Paint Pte.
Ltd.).
2. T h y c nghiem
2.1. Lwa chgn he san va chuin bj mau thep de thir nghiem, danh gia
Thu nghiem 4 he son nay len 3 loai thep dupe dung pho b i l n trong cdng nghiep:
+ Thep SS400, JIS-41, API-5L la nhQ'ng loai thep c h i tao pho b i l n d u g c s u dung eho cac cdng trinh xay dung va de c h i tao cae bon be, dudng dng trong cac edng trinh cdng nghiep d i u khi va boa chat.
+ Cac mau thep duge gia edng theo kich thudc 150 X 100 X 2 - 5mm, sau dd dugc tay saeh dau m&
phun eat theo tieu chuan Sa2,5. Oe thu' nghiem dac tinh tan nhiet eua Idp son phu, thilt bj md phdng b6n be chua va t h i l t bj trao doi nhiet duge gia edng bang thep AP1-5L. Bon be chua duge md phdng cd hinh dang b l ehua dung. TBTON la loai thilt bj md phong TBTON b l mat ngan each kieu dng.
2.2. Phwang phap danh gfa
2.2.1. Danh gia kha nang chong an mon ciia lap san phu
Phuong phap tong trd dien hoa la mgt trong cac phuong phap hO'u hieu de nghien cuu cac qua trinh an mdn dien hoa xay ra tren b l mat phan chia pha.
Day la phuong phap hien dai eho k i t qua cd do tin cay cao, cd the xac djnh dugc chinh xac cae thdng so cua mang nhu: Oien trd mang Rf, dien rung mang Cf, va danh gia dung tinh trang cua m i u , phuong phap nghien cuu khdng pha buy va phan doan duge qua trinh an mdn.
Oe do tong trd cua mang so - m i u dugc nil vdi 3 dien eye: Oien CLPC lam viec ; , t^^p ^g ^1}
ly duge phu mang son. Mau phu so,: ; ^.^up ong PVC hinh tru cd chua dung djch Na>^ .;, ijg_ x- u t i l p xuc cua b l mat vdi mdi trudng xarn u'c la
48 • s o 11/2010
28em2, (jign cue so sanh la dien cue ealomen bao hoa, dien cue doi la dien cue platin. Pho tong trd dugc do tren may AUTOLAB P30. Cac phep do dat d c h i dp quet tu ddng t u dai tan sd 100 kHz d i n 10 mHz.
2.2.2. Danh gia kha nang tan nhiet cua cac he san - Thi nghiem thuc hien vdi khoang nhiet do dudi lOO^C, day la khoang nhiet do ma eae TBTON dang lam mat thudng su dung.
- Cae bdn, b l chua chu y l u dugc dat true t i l p g ngoai trdi, chi chju tac dgng nhiet t u anh nang mat trdi do dd cac bdn, be chua chi chju khoang nhiet do cao nhat trong khoang tu 40°C - 45^0.
NhOng thiet bj md phdng duge son nhung he son da lua ehgn va tien hanh thi nghiem nhu sau:
+ Cac thilt bj md phdng bdn, be ehua dugc son nhung he son da lua ehgn sau dd duge dat trong phdng thi nghiem va duge chilu tia hdng ngoai.
+ Nhiet do khdng khi phia tren b l mat thiet bj dugc duy tri d lOO^C trong 2 gid.
+ T i l n hanh theo doi s u tang nhiet dp thanh trong va s u tang nhiet do cua Idp son ben ngoai thanh thilt bj.
3. Ket qua danh gia kha nang chong an mon, tan nhiet cua Ivp so>n phu
3.1. Kit qua danh gia kha nang chong an mon cua l&p san phu
Do k i t qua danh gia kha nang chong an mdn cua Idp son phu tren 3 loai thep SS400, JIS-41, API-5L d i u ed xu hudng gidng nhau, ehi ed k i t qua danh gia eho loai thep SS400 dugc trinh bay chi t i l t dudi day:
Sau 28 ngay ngam trong dung djch NaCI 3%
gia trj tong trd cua t i t ca cac m i u d i u cao (tren 10^ Q.cm2), chung td ca 4 he son deu cd kha nang bao ve chong an mdn cao. Mau s u dung he son D- Pol da x u l t hien mgt phan cung thu 2 d t i n sd t h i p , ehung td c h i t dien ly da d i n b l mat kim loai. Trong khi dd 3 mau s u dung he son Epoxy PUX , he son EPU TDS va he son HEPU trang chua x u l t hien cung thu 2 d t i n sd t h i p . Viec chua x u l t hien cung thu 2 d t i n sd t h i p ehung td mang son cua cac mau nay ngan each tot, c h i t dien ly chua d i n b l
mat kim loai, chua ed qua trinh an mdn kim loai.
T u pho tong trd, gia trj modul tong trd tai 10 mHz (ZiomHz) d u g c xae djnh va theo ddi theo thdi gian ngam trong dung djch NaCI 3%. Ta thay trong thdi gian t h u nghiem 5 t u i n , gia trj modul tong trd tai 10 mHz, ZiomHz cua he son D-Pol giam theo thdi gian ngam. Trong khi vdi cac he son cdn lai, gia trj nay thay doi khdng dang k l . Cac k i t qua do tong trd eho t h i y kha nang bao ve cua eae he son khac nhau: he son D-Pol cd kha nang bao ve thap n h i t , he son EPU TDS cd kha nang bao ve eao n h i t , sau dd den he son HEPU trang va he son Epoxy PUX.
410'
210
510"
.
•
- • •
*
He JOB D-Pol 28 ngay
* •
---—--1- • - - 1
210 410 610 810
2 5ltf°-
^
*
ot
• He ion Epoxy PU>[
^ 28 ngay
0 2.5 Iff 510" 7 510" 110"
610" -
of
H4 Km EPU TDS 28 ngay
2 id'
l i d ' -
510"' l i o " 1510" 2 l t f '
•
«
*
f,.
•
1
H4 ion HEPU trans 28 ngay
1 . . . 1 . . .
0 1 10" 210" 310" 4 10"
Hinh 3. Pho tdng tra cua cac he sen tren thep SS400 sau 28 ngay ngam trong dung dich NaCI 3%
Dfiu KHi-S6 11/2010 49
Bang 2. Gia tri modul tdng tra tai lOmHz (ZIQ^^J eiia cae he san tren thep SS400 theo thai gian ngam trong dung djch NaCI 3%
Thai gian ngam (ngay)
7 14 21 28 35
He sen D-Pol (Q. cm^) 1,22E+08 7,23E +07 5,63E + 07 5,05E + 07 5,02E + 07
He sen Epoxy PUX (Q. cm^) 4,82E + 10 5,96E + 10 4,37E + 10 6,87E + 10 4,89E + 10
He so'n EPU TDS (a. cm^) 1,92E+11 2,91E + 11 2,11E + 11 3,04E+ 11 3,05E+ 11
H# san HEPU Trang (a. cm^) 7,66E + 10 1,11E+11 9,10E+10 1,33E+ 11 1,07E + 11
10
1 0 "
^ 10-
N 10
10
10
10
H4 i3a Ep 37^^^'^'^\
H* 5551EF,'TDS Hi i3H HEFJ trial
I I 1 1 1 I 11 11 I 1 1 1 1 1 I
Hinh 4. Sw thay tren thep
S 10 I S 2D 25 30 3& 40 Thdi gian ngam trong dung djch NaCL 3% (ngay)
ddi gia tri modul tong tra tat lOmHz eua eae he san SS400 theo that gian ngam trong dung djch NaCI 3%
H? s e n D.Pol
Nhan xet: Cac he son deu CO tinh chat bao ve chdng an mdn cao. So sanh kha nang bao ve cua cae he son eho t h i y he son D-Pol cd tinh chat bao ve t h i p hon so vdi cac he son EPU TDS, HEPU trang va Epoxy PUX. Cd t h i s l p x i p kha nang bao ve an mdn cua cae he son theo t h u t u giam d i n nhu sau:
EPU TDS > HEPU T r i n g
> Epoxy PUX > D-Pol
3.2. Ket qua danh gia kha nang tan nhiet cOa lop san phu (Hinh 5)
He s o n ^ o x y P U X
~ Nhtel do ldp son
~ Nhiet dp thanh ben trong
20,0 40,0 60.0 80,0 100,0 120,0 Tho-igian.phut
~ Nhiet dp ldp son
~ Nhi^t dp thanh ben trong
20,0 40,0 60,0 80,0 100,0 120,0 Thoi glan.phut
H$ s o n HB>U trang
~ Nhiet dp ldp son
~ Nhi?l dp Ihanh ben trong
' Nhiet dp ldp son - Nhi?t 6if thanh ben trong
20,0 40,0 60.0 80,0 100,0 120,0 0 20,0 40.0 60,0 80,0 100,0 120,0 T h o i gian, phut thoi gian, phut
Hinh 5. Biiu dd danh gia kha nang tan nhiet cua cac he san tren thep APi-5L
50 ^ii-i ^^ -: ;o 11/2010
Nhan xet
Cac qua danh gia cho thay:
+ Cac he son Epoxy PUX, EPU TDS, HEPU tring ed kha nang h i p thu nhiet va truyin nhiet qua Idp son phu r i t cham.
+ He son D-Pol cd kha nang h i p thu nhiet va truyen nhiet qua ldp son tuong doi nhanh, s u chenh lech nhiet dp giu'a Idp son va thanh trong cua thilt bj la khdng nhieu.
+ Kha nang tan nhiet cua cac he son dup'c sap x i p theo thu t u giam dan nhu sau:
D-Pol > Epoxy PUX > EPU TDS > HEPU trang 4. Ket luan
Qua qua trinh nghien cuu, danh gia ed the dua mdt sd k i t luan sau:
+ Cac he son phu d i u b i n vdl mdi trudng khi hau nhiet ddi cua Viet Nam.
+ Cac he son d i u cd tinh nang bao ve chdng an mdn eao s u dung tdt trong mdi trudng khi hau nhiet ddi cua Viet Nam.
+ Ddi vdi cac bdn, b l chua dupe dat d nhQ'ng vung ed tdc dp an mdn kim loai cao, thdi gian nang va nhiet dp trung binh trong ngay eao va keo dai thi su dung he son HEPU Tring va EPU TDS la hieu qua nhit vi cac he son nay cd kha nang bao ve chong an mdn r i t eao, kha nang phan xa lai buc xa mat trdi r i t tdt.
+ o i l vdi eae TBTON dang thilt bj lam mat e i n phai tan nhiet nhanh ra ngoai mdi trudng thi s u dung he son D-Pol la tdt n h i t vi he son nay ed kha nang h i p thu nhiet va tan nhiet nhanh.
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MocKBa HEflPA 2000.
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10. Tai lieu khi hau khu vue Dinh Vu - Hai Phdng nam 2008 - 2009.
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A. LUnyrepa. ranbBaHMMecKne noKpbiTMfi B Maiun-
HOCTpOeHMki CnpaaOHHUK. MaLUUHHOCTpOeHMfl
1985.
16. Sauiuma om Koposua cmapoHUfi u 6uono- epe>KdeHafi MauiUH odpydoeaHUfi u coopyxeHuii.
CnpaBOMHMK. MocKBa wiaujMHOCTpoiliHMe 1957.
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