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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
MUC LUC
trangLI M AU
CHNG I : TONG QUAN.......................................I . LY THUYET VE CHNG CAT1 . Phng phap chng cat2 .Thiet b chng cat:
II . GII THIEU S BO NGUYEN LIEU1 . Acid axetic2 . Nc3 . Hon hp Acid axetic Nc
III . CONG NGHE CHNG CAT HE ACID AXETICNCCHNG II : CAN BANG VAT CHATI . CAC THONG SO BAN AUII . XAC NH SUAT LNG SAN PHAM NH VASAN PHAM AY
III . XAC NH T SO HOAN LU THCH HP1 .T so hoan lu toi thieu2 .T so hoan lu thch hp
IV . PHNG TRNH NG LAM VIEC SO MAMLY THUYET1 . Phng trnh ng nong o lam viec cua
oan cat2 . Phng trnh ng nong o lam viec cua
oan chng3 . So mam ly thuyet
V . XAC NH SO MAM THC TE
CHNG III :TNH TOAN THIET KE THAPCHNG CATI . NG KNH THAP1 . ng knh oan cat2 . ng knh oan chng
II . MAM LO TR LC CUA MAM1 . Cau tao mam lo2 . o giam ap cua pha kh qua mot mam3 . Kiem tra ngap lut khi thap hoat ongO(
III .TNH TOAN C KH CUA THAP
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
1 . Be day than thap :2 . ay va nap thiet b :3 . Bch ghep than, ay va nap :4 . ng knh cac ong dan Bch ghep cac
ong dan :5 . Tai treo va chan :
CHNG IV : TNH TOAN THIET B TRUYENNHIET- THIET B PHU
I . CAC THIET B TRUYEN NHIET1 . Thiet b ngng tu san pham nh2 . Thiet b lam nguoi san pham nh3 . Noi un gia nhiet san pham ay
4 . Thiet b trao oi nhiet gia nhap lieu vasan pham ay5 . Thiet gia nhiet nhap lieu
II.TNH BAO ON CUA THIET BIII .TNH TOAN BM NHAP LIEU1 . Tnh chieu cao bon cao v2 . Chon bm
CHNG V : GIA THANH THIET BI .TNH S BO GIA THANH CUA THIET B
II . KET LUANTAI LIEU THAM KHAO
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
LI M AU
Mot trong nhng nganh co s ong gop to ln ennganh cong nghiep nc ta noi rieng va the gii noi
chung, o la nganh cong nghiep hoa hoc. ac biet langanh hoa chat c ban.Hien nay, trong nhieu nganh san suat hoa hoc cung nh
s dung san pham hoa hoc, nhu cau s dung nguyenlieu hoac san pham co o tinh khiet cao phai phu hpvi quy trnh san suat hoac nhu cau s dung.
Ngay nay, cac phng phap c s dung e nang caoo tinh khiet: trch ly, chng cat, co ac, hap thu Tuytheo ac tnh yeu cau cua san pham ma ta co s lachon phng phap thch hp. oi vi he acid axetic- Nc
la 2 cau t tan lan hoan toan, ta phai dung phngphap chng cat e nang cao o tinh khiet cho acid axetic.o an mon hoc Qua trnh va Thiet b la mot mon
hoc mang tnh tong hp trong qua trnh hoc tap cua cacky s hoa- th c pham tng lai. Mon hoc giup sinh viengiai quyet nhiem vu tnh toan cu the ve: yeu cau congnghe, ket cau, gia thanh cua mot thiet b trong sanxuat hoa chat - thc pham. ay la bc au tien esinh vien van dung nhng kien thc a hoc cua nhieumon hoc vao giai quyet nhng van e ky thuat thc
te mot cach tong hp.Nhiem vu cua AMH la thiet ke thap chng cat he acidaxetic - Nc hoat ong lien tuc vi nang suat nhaplieu : 5m3/h co nong o 8% mol acid axetic ,thu c sanpham nh co nong o 0.5% mol acid axetic vi nng odung dch ay acid axetic la 30%.
Em chan thanh cam n cac qu thay co bo mon May &Thiet B, cac ban sinh vien a giup em hoan thanh oan nay. Tuy nhien, trong qua trnh hoan thanh o ankhong the khong co sai sot, em rat mong qu thay co
gop y, ch dan.
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
CHNG I : TONG QUAN.
I . LY THUYET VE CHNG CAT:1 . Phng phap chng cat :
Chng cat la qua trnh phan tach hon hp long (hoackh long) thanh cac cau t rieng biet da vao s khacnhau ve o bay hi cua chung (hay nhiet o soi khacnhau cung ap suat), bang cach lap i lap lai nhieulan qua trnh bay hi - ngng tu, trong o vat chat i tpha long vao pha hi hoac ngc lai. Khac vi co ac,chng cat la qua trnh trong o ca dung moi va chat taneu bay hi, con co ac la qua trnh trong o ch codung moi bay hi.
Khi chng cat ta thu c nhieu cau t va thng thbao nhieu cau t se thu c bay nhieu san pham.Neu xet he n gian ch co 2 he cau t th ta thuc 2 san pham: san pham nh chu yeu gom gomcau t co o bay hi ln (nhiet o soi nho ), sanpham ay chu yeu gom cau t co o bay hibe(nhiet o soi ln) .oi vi he acid axetic - nc sanpham nh chu yeu gom nc va mot t acid axetic ,ngc lai san pham ay chu yeu gom acid axetic vamot t nc.
Cac phng phap chng cat: c phan loai theo: Ap suat lam viec : chng cat ap suat thap, apsuat thng va ap suat cao. Nguyen tac cuaphng phap nay la da vao nhiet o soi cua caccau t, neu nhiet o soi cua cac cau t qua caoth ta giam ap suat lam viec e giam nhiet osoi cua cac cau t.
Nguyen ly lam viec: lien tuc, gian oan(chng ngian) va lien tuc.* Chng cat n gian(gian oan): phng phap nay
uc s dung trong cac trng hp sau:+ Khi nhiet osoi cua cac cau t khac xa nhau.+ Khong oi hoi san pham co o tinh khiet cao.+ Tach hon hp long ra khoi tap chat khong bay
hi.+ Tach s bo hon hp nhieu cau t.
* Chng cat hon hp hai cau t (dung thiet b hoatong lien tuc) la qua trnh c thc hien lien tuc,nghch dong, nheu oan.
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Phng phap cap nhiet ay thap: cap nhiet trctiep bang hi nc: thng c ap dung trng hpchat c tach khong tan trong nc .
Vay: oi vi he acid axetic Nc, ta chon phngphap chng cat lien tuc cap nhiet gian tiep bang noiun ap suat thng.
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
2 . Thiet b chng cat:Trong san xuat thng s dung rat nhieu loai thap
nhng chung eu co mot yeu cau c ban la dien tchbe mat tiep xuc pha phai ln ,ieu nay phu thuoc
vao o phan tan cua lu chat nay vao lu chat kia .Thap chng cat rat phong phu ve kch c va ngdung ,cac thap ln nhat thng c ng dung trongcong nghiep loc hoa dau. Kch thc cua thap : ngknh thap va chieu cao thap tuy thuoc suat lng phalong, pha kh cua thap va o tinh khiet cua san pham.Ta khao sat 2 loai thap chng cat thng dung la thapmam va thap chem.
Thap mam: than thap hnh tru, thang ng phatrong co gan cac mam co cau tao khac nhau e
chia than thap thanh nhng oan bang nhau, trenmam pha long va pha hi c cho tiep xuc vi nhau.Tuy theo cau tao cua a, ta co:
* Thap mam chop : tren mam co chop dang tronhay mot dang khac,co ranh xung quanh e pha kh iqua va ong chay chuyen co hnh tron
* Thap mam xuyen lo: tren mam bo tr cac loco ng knh 3-12mm c bo tr tren cac nh tamgiac,bc lo bang 2,5 en 5 lan ng knh Thap chem(thap em): thap hnh tru, gom nhieu
oan noi vi nhau bang mat bch hay han. Vat chemc cho vao thap theo mot trong hai phng phap:xep ngau nhien hay xep th t.
So sanh u va nhc iem cua cac loaithap :
Thap
chem.Thap mam
xuyen lo.Thap mamchop.
uiem: - n gian.
- Hieu suat tngoi cao. - Hieu suat cao.
- Tr lc
thap.
- Hoat ong kha
on nh.
- Hoat ong on
nh.- Lam viec vichat long ban.
Nhciem:
- Hieu suatthap.
- Tr lc kha cao. - Cau tao phctap.
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- Thiet bnang.
- Khong lamviec vi chatlong ban.
- o on nhkem.
- Yeu cau lapat khat khe ->lap a thatphang. - Tr lc ln.
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Nhan xet: thap mam xuyen lo la trang thaitrung gian gia thap chem va thap mam chop. Nenta chon thap chng cat la thap mam xuyen lo.
Vay: Chng cat he acid axetic - Nc ta dung thapmam xuyen lo hoat ong lien tuc ap suat thng,cap nhiet gian tiep ay thap.
II . GII THIEU S BO NGUYEN LIEU:Nguyen lieu la hon hp acid axetic - Nc.
1 . Etanol:(Con goi la ru etylic , con etylic hay conthc pham).
Etanol co cong thc phan t: CH3-CH2-OH, khoi lngphan t: 46 vC. La chat long co mui ac trng, khongoc, tan nhieu trong nc.
Mot so thong so vat ly va nhiet ong cua etanol:
+ Nhiet o soi 760(mmHg): 78.3oC.+ Khoi lng rieng: d420 = 810 (Kg/m3).Tnh chat hoa hoc:
Tat ca cac phan ng hoa hoc xay ra nhomhydroxyl (-OH) cua etanol la the hien tnh chat hoahoc cua no.
* Phan ng cua hydro trong nhom hydroxyl:CH3-CH2-OH CH3-CH2-O- + H+
Hang so phan ly cua etanol: 181023
=OHCHCHK , cho
nen etanol la chat trung tnh.+ Tnh acid cua ru the hien qua phan ng vikim loai kiem, Natri hydrua(NaH), Natri amid(NaNH2):
CH3-CH2-OH + NaH CH3-CH2-ONa + H2Natri etylat
Do 1410223
=< OHOHCHCH KK : tnh acid cua ru nho
hn tnh acid cua nc, nen khi muoi Natri etylat tantrong nc se b thuy phan thanh ru tr lai.
+ Tac dung vi acid tao ester: Ru etanol co tnhbaz tng ng vi nc. Khi ru tac dung vi
acid vo c H2SO4, HNO3 va acid hu c eu tao raester.
CH3-CH2-OH + HO-SO3-H CH3-CH2O-SO3-H+ H2O
CH3-CH2O-H + HO-CO-CH3 CH3-COO-C2H5 +H2O
* Phan ng tren nhom hydroxyl:+ Tac dung vi HX: CH3-CH2-OH + HX CH3-
CH2-X + H2O+ Tac dung vi Triclo Phot pho:
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Lanh
H+
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
CH3-CH2-OH + PCl3 CH3-CH2-Cl + POCl + HCl
+ Tac dung vi NH3: CH3-CH2-OH + NH3C2H5-NH2 + H2O
+ Phan ng tao eter va tach loai nc:
2CH3-CH2-OH (CH3-CH2)2O + H2O
CH3-CH2-OH CH2=CH2 + H2O
* Phan ng hydro va oxy hoa:
CH3-CH2-OH CH3-CHO + H2
ng dung: etanol co nhieu ng dung hn metanol, noong mot vai tro quan trong trong nen kinh te quocdan. No la nguyen lieu dung e san suat hn 150mat hang khac nhau va c ng dung rong raitrong cac nganh: cong nghiep nang, y te va dc,quoc phong, giao thong van tai, det, che bien gova nong nghiep.
S o tom tat v tr cua etanol trong cacnganh cong nghiep.
Phng phap ieu che: co nhieu phng phap ieuche etanol: hydrat hoa etylen vi xuc tac H2SO4; thuyphan dan xuat halogen va ester cua etanol khi unnong vi nc xuc tac dung dch baz; hydro hoaaldyhyt acetic; t cac hp chat c kim
10
Al2O
3
to
H2SO
4
>150o
CH2SO
4
>150o
C
Cu200-300oC
+ Thuoc sung khongkhoi.
+ ong lc.+ Thuoc trsau.
+ Sn.+Vecni.
+ o nha.+ Keo dan.+ Hnglieu.
+ Sat trung.+ Pha chethuoc.
+ Thuocnhuom.+ T nhan
tao.
+ Rumui.+ Dam.
+ Dung moi huc:pha sn..+ Nguyen lieu.
+ Cong nghiep cao sutong hp+ ong lc.
Nhienlieu.
Etanol
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Trong cong nghiep, ieu che etanol bang phngphap len men t nguon tinh bot va r ng. Nhngnam gan ay, nc ta cong nghe san suat etanolchu yeu la s dung chung nam men Saccharomysescerevisiae e len men tinh bot:
C6H6O6 2C2H5OH + 2CO2 + 28 Kcal
Trong o: 95% nguyen lieu chuyen thanh etanolva CO2.
5% nguyen lieu chuyen thanh san phamphu: glyxerin, acid sucxinic, dau fusel, metylic vacac acid hu c(lactic, butylic).
2 . Nc:Trong ieu kien bnh thng: nc la chat long khong
mau, khong mui, khong v nhng khoi nc day se comau xanh nhat.Khi hoa ran no co the ton tai dang 5 dang tinh
the khac nhau:Khoi lng phan t : 18 g / molKhoi lng rieng d40 c : 1 g / mlNhiet o nong chay : 00CNhiet o soi : 1000 C
Nc la hp chat chiem phan ln tren trai at (3/4dien tch trai at la nc bien) va rat can thiet cho s
song.Nc la dung moi phan cc manh, co kha nang hoatan nhieu chat va la dung moi rat quan trong trong kythuat hoa hoc.3 . Hon hp Etanol Nc:
Ta co bang thanh phan long (x) hi (y) va nhiet osoi cua hon hp Etanol - Nc 760 mmHg:
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x(%phanmol) 0 5 10 20 30 40 50 60 70 80 90 100
y(%phan
mol) 0 9.2 16.7 30.3 42.5 53 62.6 71.6 79.5 86.4 93 100t(oC) 118.4 115.4 113.8 110.1 107.5 105.8 104.4 103.3 102.1 101.3 100.6 100
Nammen
Zymaza
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
0 0
5 9.2 0
10 16.7 10
20 30.3 20
30 42.5 30
40 53 40
50 62.6 50
60 71.6 60
70 79.5 70
80 86.4 80
90 93 90
100 100 100
92
99.5
920
10
20
30
40
50
60
70
80
90
100
X(% mol
Y(%mol)
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
III. CONG NGHE CHNG CAT HE ETANOL NC:
Etanol la mot chat long tan vo han trong H2O, nhiet osoi la 78,30C 760mmHg, nhiet o soi cua nc la
100o
C 760mmHg : hi cach biet kha xa nen phng phaphieu qua e thu etanol co o tinh khiet cao la phngphap chng cat.
Trong trng hp nay, ta khong the s dung phngphap co ac v cac cau t eu co kha nang bay hi,va khong s dung phng phap trch ly cung nh phngphap hap thu do phai a vao mot khoa mi e tach,co the lam cho qua trnh phc tap hn hay qua trnh tachkhong c hoan toan.
* S o qui trnh cong nghe chng cat he Etanol
nc:Chu thch cac k hieu trong qui trnh:1 . Bon cha nguyen lieu.2 . Bm.3 . Bon cao v.4 . Lu lng ke.5 . Thiet b trao oi nhiet vi san pham ay.6 . Thiet b gia nhiet nhap lieu.7 . Bay hi.8 . Thap chng cat.
9 . Nhiet ke.10 . Ap ke.11 . Thiet b ngng tu san pham nh.12 . Noi un.13 . Thiet b lam nguoi san pham nh.14 . Bon cha san pham nh.15 . Bon cha san pham ay.16 . Bo phan phan dong.
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
ang
LI MAUCHNG I : TONG
I .LYTHUYET VE1 .Phng phap c
2 .Thiet bchngII .GII THIEU S1 . Acid axetic
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
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386387388389390391392393394395396397398399400401402403404405406
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
* Thuyet minh qui trnh cong nghe:Hon hp etanol nc co nong o etanol 10% ( theo
phan mol), nhiet o khoang 280C tai bnh cha nguyenlieu (1) c bm (2) bm len bon cao v (3). T o ca en thiet b trao oi nhiet (5) ( trao oi nhiet visan pham ay ). Sau o, hon hp c un soi ennhiet o soi trong thiet b gia nhiet(6), hon hp ca vao thap chng cat (8) a nhap lieu.
Tren a nhap lieu, chat long c tron vi phanlong t oan cat cua thap chay xuong. Trong thap hi,i t di len gap chat long t tren xuong. ay,co s tiep xuc va trao oi gia hai pha vi nhau. Phalong chuyen ong trong phan chng cang xuong dicang giam nong o cac cau t de bay hi v a b pha
hi tao nen t noi un (12) loi cuon cau t de bayhi.Nhiet o cang len tren cang thap, nen khi hi i quacac a t di len th cau t co nhiet o soi cao lanc se ngng tu lai, cuoi cung tren nh thap ta thuc hon hp co cau t etanol chiem nhieu nhat (conong o 85% phan mol). Hi nay i vao thiet b ngng tu(11) va c ngng tu hoan toan. Mot phan chat longngng tu i qua thiet b lam nguoi san pham nh (13),c lam nguoi en 350C , roi c a qua bon chasan pham nh (14). Phan con lai cua chat long ngng
tu c hoan lu ve thap a tren cung vi t sohoan lu toi u. Mot phan cau t co nhiet o soi thapc boc hi, con lai cau t co nhiet o soi cao trongchat long ngay cang tang. Cuoi cung, ay thap tathu c hon hp long hau het la cac cau t kho bayhi ( nc). Hon hp long ay co nong o etanol la0,11 % phan mol, con lai la nc. Dung dch long ay ira khoi thap vao noi un (12). Trong noi un dung dchlong mot phan se boc hi cung cap lai cho thap e tieptuc lam viec, phan con lai ra khoi noi un c trao oi
nhiet vi dong nhap lieu trong thiet b (5) (sau khi quabon cao v).He thong lam viec lien tuc cho ra san pham nh la
etanol, san pham ay sau khi trao oi nhiet vi nhaplieu co nhiet o la 600C c thai bo.
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
CHNG II : CAN BANG VATCHAT .
I . CAC THONG SO BAN AU : Nang suat nhap lieu:
(x
=x1*M1/(x1*M1+(1-x1)*M2)=(0.08*60)/(0.08*60+0.92*18)=20/89=0.2247
1/nat b
xx /)1(/ += =20/89/1039.6+(1-20/89)/995.6, tb
=1005.16kg/m3) GF=QF* tb =5*1005.16=5025.8(kg/h).
Nong o nhap lieu : xF = 8% mol acid axetic(xF=0.92)
Nong o san pham nh : xD = 0.5% mol acidaxetic( xD=0.995)
Nong o san pham ay : xW = 30% mol acid axetic.(xW=0.7) Khoi lng phan t cua acid axetic va nc : MA =60
kg/kmol , MN =18 kg/kmol . Chon :
+ Nhiet o nhap lieu : tF =28oC .+ Nhiet o san pham nh sau khi lam nguoi : tD
=35oC .+ Nhiet o san pham ay sau khi trao oi nhiet : tW
= 35oC .+Trang thai nhap lieu la trang thai long soi .
Cac k hieu :+ GF , F : suat lng nhap lieu tnh theo Kg/h , Kmol/h .+ GD , D : suat lng san pham nh tnh theo Kg/h ,
Kmol/h .+ GW ,W : suat lng san pham ay tnh theo Kg/h ,
Kmol/h .+ xi , ix : phan mol , phan khoi lng cua cau t i .
II . XAC NH SUAT LNG SAN PHAM NH
VA SAN PHAM AY:
18
69
452453454455456
457
458
459
460461
462
463
464465
466
467468469470471472
473474475476
477478479480481482
483484485486487488489490
491
492
70
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Can bang vat chat cho toan thap : F = D + W(II.1)
Can bang cau t : F.xF = D.xD + W.xW (II.2)Vi : * Phan mol nhap lieu : xF = 8%(phan mol acid
axetic ).Khoi lng phan t trung bnh dong nhap lieu :MF = 18).1(.60 FF xx + = 21.36 (Kg/Kmol).
F =F
F
M
G=
36.21
8.5025=235.29 (Kmol/h)
*Phan mol san pham nh : xD =0,5% (phan molacid axetic) .
Khoi lng phan t trung bnh dong san pham
ay :
MW = 18).1(.60 WW xx + = 30.6 (Kg/Kmol).Khoi lng phan t trung bnh dong san phamnh :
MD = 18).1(.60 DD xx + =18.21 (Kg/Kmol).Giai 2 phng trnh (II.1),(II.2)ta co :
19
73
493494495496497498499
500
501502503504505
506507508509510
74
8/3/2019 Ccat Acid Acetic-Nuoc(Mam Xuyen Lo)
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
D =175.47 (Kmol/h)W = 59.819 (Kmol/h)
III . XAC NH T SO HOAN LU THCH HP :
1 . T so hoan lu toi thieu:T so hoan lu toi thieu la che o lam viec ma taio ng vi so mam ly thuyet la vo cc .Do o ,chi phco nh la vo cc nhng chi ph ieu hanh (nhien lieu,nc va bm) la toi thieu .
Do o th can bang cua he acid axetic -Nc co iemuon ,nen xac nh t so hoan lu toi thieu bang cach :
+Tren o th can bang y-x ,t iem (0.995,0.995) take mot ng thang i qua iem (xF,y*F) cat truc Oy taiiem co yo = 0.32.
+Theo phng trnh ng lam viec oan cat , khi xo =0th
yo =1min +R
xD =0.32
Vay : t so hoan lu toi thieu : Rmin = 2.109or
Rmin=
xy
yx
FF
FD
*
*=
92.0945.0
945.0995.0
=2
T so hoan lu thch hp:RX=1.3Rmin+0.3=2.92. T so hoan lu thch hp:
Khi R tang, so mam se giam nhng ng knh thap,thiet b ngng tu ,noi un va cong e bm cung tangtheo.Chi ph co nh se giam dan en cc tieu roi tangen vo cc khi hoan lu toan phan ,lng nhiet va lngnc s dung cung tang theo t so hoan lu .
Tong chi ph bao gom : chi ph co nh va chi ph ieuhanh . T so hoan lu thch hp ng vi tong chi ph lacc tieu .
Tuy nhien ,oi khi cac chi ph ieu hanh rat phctap ,kho kiem soat nen ngi ta co the tnh t so hoanlu thch hp t ieu kien thap nho nhat .e tnh ct so hoan lu thch hp theo ieu kien thap nho nhat(khong tnh en chi ph ieu hanh),ta can lap moi quanhe gia t so hoan lu va the tch thap ,t o chon Rthng vi the tch thap la nho nhat.
Nhan thay ,tiet dien thap t le vi lng hi i trongthap ,ma lng hi lai t le vi lng long hoi lu trong
20
77
511512513
514
515516517518519520521522523524
525526
527
528529
530
531
532533534535536537538539540541542543544545546547
548549
78
8/3/2019 Ccat Acid Acetic-Nuoc(Mam Xuyen Lo)
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
thap ,do trong ieu kien lam viec nhat nh th GD sekhong oi nen lng long hoi lu se t le vi (R+1) ,doo , tiet dien thap se t le vi (R+1). Ngoai ra ,chieucao thap t le vi so n v chuyen khoi mox hay somam ly thuyet Nlt .Cho nen ,the tch lam viec cua thapt le vi tch so mox*(R+1) .Nh vay, ta co the thiet lapquan he gia R va Vthap theo quan he R va mox*(R+1) .To th cua quan he nay ,ta xac nh c iem cc tieucua mox*(R+1) ng vi t so hoan lu thch hp R .
R mox mox*(R+1)
2.496 47.818 167.173
2.723 37.733 140.480
2.973 32.801 130.320
3.023 33.545 134.952
120
130
140
150
160
170
2.00 2.50 3.00 3.50
R
R*(mox+1)
Vay : T so hoan lu thch hp la R= 2,973 .IV . PHNG TRNH NG LAM VIECSO
MAM LY THUYET:1 . Phng trnh ng nong o lam vieccua oan cat :
y =1
.1
.
++
+ Rx
xR
R D =19,2
995,0.
19,2
9,2
++
+x
=0,7436.x + 0.25512 . Phng trnh ng nong o lam viec
cua oan chng :
y = WxR
fx
R
fR.
1
1.
1 +
+
+
+= 7.0.
19,2
1341.1.
19,2
341.19,2
+
+
+
+x
= 1.087x 0.0612
21
81
550551552553554555556557558559
560
561562
563
564565
566
567
568
569
570
571
572
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Vi : f =47.175
29.235=
D
F= 1.341 : ch so nhap lieu .
3 . So mam ly thuyet :o th xac nh so mam ly thuyet :(Xem hnh trang
sau ).
T o th ,ta co : 29 mam bao gom : 19 mam cat
1 mam nhap lieu
22
85
573
574575576577578579580581582583584585586587588589590591592593594595
596597598599600601602603604605
606607608609610611612613614615
616
86
8/3/2019 Ccat Acid Acetic-Nuoc(Mam Xuyen Lo)
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
5 mam chng(4 mamchng+1 noi un)Tom lai ,so mam ly thuyet la Nlt = 28 mam .
V . XAC NH SO MAM THC TE:
So mam thc te tnh theo hieu suat trung bnh :
tb
lt
tt
NN = (st2/170)
trong o: tb : hieu suat trung bnh cua a, la motham so cua o bay hi tng oi va o nht cua honhp long : = f( , ).
Ntt : so mam thc te.
Nlt : so mam ly thuyet.
Xac nh hieu suat trung bnh cua thap tb :+ o bay tng oi cua cau t de bay hi :
x
x1
y1
y*
*
=
Vi : x :phan mol cua nc trong pha long .y* : phan mol cua nc trong pha hi can bang
vi pha long.* Tai v tr nhap lieu :
xF = 0.92 ta tra o th can bang cua he : y*F =0.945
tF = 100.52 oC
+92.0
92.01.
945.01
945.0
x
x1
y1
y
F
F
*
*
F
=
=F
F= 1.494
+ T %12,22=Fx va tF = 100.52 oC ,tra tai lieu thamkhao [4(tap 1) trang 107] : F =43.10-6.9,81 =0,422.10-3 (N.s/m2)
= 0,422 (cP)Suy ra : F . F = 7,129.0,422 =3,007
Tra tai lieu tham khao [4(tap 2) trang 171] : F =
0,395* Tai v tr mam ay :xW = 0.7 ta tra o th can bang cua he : y*W = 0.795
tW = 102.1 oC
+7.0
7.01.
795.01
795.0
x
x1
y1
y
W
W
*
*
W
=
=
W
W= 1.662
+ T %29,018).1(.46
.46=
+=
WW
W
Wxx
xx va tW = 100 oC ,tra tai
lieu tham khao [4(tap 1) trang 107] :
W =25.10-6
.9,81= 0,245.10-3
(N.s/m2
)= 0,245 (cP)
23
89
617618619
620621
622
623624
625626
627
628
629
630
631632633634635636637
638
639
640641642
643
644645646647648
649
650
651
652653
90
8/3/2019 Ccat Acid Acetic-Nuoc(Mam Xuyen Lo)
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Suy ra : W . W = 16,177.0,245 = 3,967Tra tai lieu tham khao [4(tap 2) trang 171] : W =
0,365*Tai v tr mam nh :
xD = 0.995 ta tra o th can bang cua he : y
*
D =0.997tD = 100.22 oC
+995.0
995.01.
997.01
997.0
x
x1
y1
y
D
D
*
*
D
=
=
D
D
= 1.67
+ T %5,9318).1(.46
.46=
+=
DD
D
Dxx
xx va tD = 78,5 oC ,tra tai
lieu tham khao [4(tap 1) trang 107] : D =51.10-6.9,81= 0,500.10-3 (N.s/m2)
= 0,500 (cP)Suy ra : D . D = 1,049.0,500 = 0,525Tra tai lieu tham khao [4(tap 2) trang 171] : D =
0,600Suy ra: hieu suat trung bnh cua thap :
tb = 4567,03
600,0365,0395,0
3=
++=
++ DWF
So mam thc te cua thap Ntt :
4567,0
28=ttN =52,55 mam
Vay chon Ntt = 53 mam , gom : 42 mam cat1 mam nhap lieu10 mam chng
24
93
654
655656657658659660
661
662
663
664
665666
667668669
670
671
672
673674675676677678679680681682
683684685686
94
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
CHNG III :TNH TOAN THIETKE THAP CHNG CAT .
I . NG KNH THAP :(Dt)
tbyytbg).(
0188,0.3600.
4VDtb
tbt
== (m)(t2 tr181)
Vtb :lng hi trung bnh i trong thap (m3/h). tb :toc o hi trung bnh i trong thap (m/s).gtb : lng hi trung bnh i trong thap (Kg/h).
Lng hi trung bnh i trong oan chng va oan catkhac nhau.Do o, ng knh oan chng va oan catcung khac nhau .
1. ng knh oan cat :a . Lng hi trung bnh i trong thap :
2
1ggg dtb+
= (Kg/h)
gd : lng hi ra khoi a tren cung cua thap (Kg/h).g1 : lng hi i vao a di cung cua oan cat
(Kg/h). Xac nh gd : gd = D.(R+1) =175.47(2,9+1) = 684.333
(Kmol/h)= 40973.75(Kg/h)(V MthD =60.yD+(1-yD).18 = 59.874Kg/Kmol).
Xac nh g1 :T he phng trnh :
=
+=
+=
dd
D
rgrg
xDxGyg
DGg
..
...
11
1111
11
(III.1)
Vi : G1 : lng long a th nhat cua oan cat .r1 : an nhiet hoa hi cua hon hp hi i vao a
th nhat cua oan cat
rd : an nhiet hoa hi cua hon hp hi i ra nh thap .* Tnh r1 : t1 = tF = 100.52oC , tra tai lieu tham khao [4
(tap 1)] ta co :An nhiet hoa hi cua nc : rN1 = 40512.96
(KJ/kmol) .An nhiet hoa hi cua acid : rR1 = 24195.24 (KJ/kmol) .Suy ra : r1 = rR1.y1 + (1-y1).rN1 = 40512.96 16317.72y1
(KJ/kmol)* Tnh rd : tD = 100.22oC , tra tai lieu tham khao IV (tap
1) ta co :
25
97
687
688
689
690
691
692693694695696
697698
699
700701702703704705706
707
708
709710711
712713714715716717718719720721
722
98
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
An nhiet hoa hi cua nc : rNd = 40512.96(KJ/kmol) .
An nhiet hoa hi cua acid : rRd = 24195.24(KJ/kmol) .Suy ra : rd = rRd.yD + (1-yD).rNd =24195.24*0.997 + (1-
0.997)*40512.96= 24244.193 (KJ/kmol)
* x1 = xF = 0.92Giai he (III.1) , ta c : G1 = 483.96 (Kmol/h)
y1 = 0.647 (phan mol acid) _ M1=45.174
g1 = 958.43 (Kmol/h) = 43297.02(Kg/h)
Vay : gtb =2
02.4329775.40973 +=42135.38(Kg/h)
b . Toc o hi trung bnh i trong thap :Toc o gii han cua hi i trong thap vi mam xuyen
lo co ong chay chuyen :
ytb
xtbgh
.05,0=
Vi : xtb : khoi lng rieng trung bnh cua pha long(Kg/m3) .
ytb : khoi lng rieng trung bnh cua pha hi(Kg/m3) . Xac nh ytb :
( )[ ]( )273.4,22
273.18.160.
++
=tb
tbtbytbt
yy
Vi: + Nong o phan mol trung bnh : ytb =2
1 Dyy + =
2
997.0647.0 +=0.822
+ Nhiet o trung bnh oan cat : ttb =2
DF tt + =
2
22.10052.100 +=100.37oC
Suy ra : ytb =1.745 (Kg/m3). Xac nh xtb :
Nong o phan mol trung bnh : xtb =2
DF xx + =2
099592.0 +=
0.4577
Suy ra :18).1(.60
.60
tbtb
tb
tbxx
xx
+= =0.7378 .
ttb = 100.37oC , tra tai lieu tham khao [4 (tap 1)-trang 9],ta co :
a=958kg/m
3
n =958 kg/m
3
26
101
723724725726727728729730731732733
734
735736737
738
739740
741742
743
744
745
746
747
748
749750
751
752
753
754755
756
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
1/nat b
xx /)1(/ +=
xtb = 958 (Kg/m3)
Suy ra :745.1
958.05,0=gh =1.172 (m/s)
e tranh tao bot ta chon toc o hi trung bnh i trongthap :
172.1.8,0.8,0 == ghh = 0.9376 (m/s)Vay :ng knh oan cat :
Dcat =9376.0.745.1
38.42135.0188,0 = 3.017 (m).
2. ng knh oan chng :a . Lng hi trung bnh i trong thap :
2
1,,
, gg
g
ntb
+
= (Kg/h)gn : lng hi ra khoi oan chng (Kg/h).g1 : lng hi i vao oan chng (Kg/h).
Xac nh gn : gn = g1 = 561,873 (Kg/h) Xac nh g1 :T he phng trnh :
==
+=
+=
1111
1'
11'
1'
1'
.'.''.'
..'.
rgrgrg
xWygxG
WgG
nn
WW(III.2)
Vi : G1 : lng long a th nhat cua oan chng .r1 : an nhiet hoa hi cua hon hp hi i vao a
th nhat cua oan chng.* Tnh r1 : xW =0,0011 tra o th can bang cua he ta
co : yW =0,018Suy ra :Mtbg =46.yW +(1-yW).18=18,504 (Kg/kmol)t1 = tW = 100oC , tra tai lieu tham khao [4 (tap 1)],
ta co :An nhiet hoa hi cua nc : rN1 = 40680
(KJ/kmol) .An nhiet hoa hi cua ru : rR1 = 36394,3
(KJ/kmol) .Suy ra : r1 = rR1.yW + (1-yW).rN1 = 40543,9 (KJ/kmol)
* Tnh r1: r1 = 41280 3885.y1 =412803885.0,297=40126,155(KJ/kmol)
* W = 42,477 (Kmol/h)Giai he (III.2) , ta c : x1 =0,0067(phan mol etanol) _
MtbG =18,189 G1 = 63,608 (Kmol/h) =
27
105
757
758
759
760761762763
764
765766
767
768769770771
772
773774775776777778779780
781782783784785786787788789790791
106
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
g1 = 21,131 (Kmol/h) = 391,008(Kg/h)
Vay : gtb = 441,4762
008,391873,561=
+(Kg/h)
b . Toc o hi trung bnh i trong thap :Toc o gii han cua hi i trong thap vi mam xuyen
lo co ong chay chuyen :
ytb
xtbgh
'
'.05,0'
=
Vi : 'xtb : khoi lng rieng trung bnh cua pha long(Kg/m3) .
'ytb : khoi lng rieng trung bnh cua pha hi(Kg/m3) . Xac nh ytb :
( )[ ]( )273'.4,22
273.18.'146.'
' +
+
= tbtbtb
ytbt
yy
Vi: + Nong o phan mol trung bnh :
ytb =2
1 Wyy + =2
018,0297,0 +=0,1575
+ Nhiet o trung bnh oan chng : ttb =2
WF tt + =
2
1005,86 +=93,25oC
Suy ra : ytb =0,746 (Kg/m3).
Xac nh xtb :Nong o phan mol trung bnh : xtb =
2
WF xx + =2
0011,010,0 +
= 0,051
Suy ra :18).'1('.46
'.46'
tbtb
tb
tbxx
xx
+= =11,98% .
ttb = 93,25oC , tra tai lieu tham khao [4 (tap 1)-trang9], ta co :
Khoi lng rieng cua nc : N = 963,117(Kg/m3)
Khoi lng rieng cua ru : R = 720,365(Kg/m3
)Suy ra : xtb =
1
'
'1
'
'
+
N
tb
R
tb xx
=925,744 (Kg/m3)
Suy ra :746,0
744,925.05,0' =gh =1,762 (m/s)
e tranh tao bot ta chon toc o hi trung bnh i trongthap :
762,1.8,0'.8,0' == ghh = 1,409 (m/s)Vay :ng knh oan cat :
Dchng= 409,1.746,0441,476
.0188,0 = 0,400 (m).
28
109
792
793
794795
796
797
798799
800801
802
803
804
805
806
807
808
809
810
811
812
813814
815
816817
818
819820821822
823
110
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Ket luan : hai ng knh oan cat va oan chngkhong chenh lech nhau qua ln nen ta chon ng knhcua toan thap la : Dt = 0,500 (m).
Khi o toc o lam viec thc :
+ Phan cat : lv = 903,0171,1.5,0768,747.0188,0
.
.0188,02
2
2
2
==ytbt
tb
D
g
(m/s).
+ Phan chng : lv = 903,0746,0.5,0
441,476.0188,0
'.
'.0188,02
2
2
2
==ytbt
tb
D
g
(m/s).II . MAM LO TR LC CUA MAM :1 . Cau tao mam lo :
Chon : + ng knh lo : dl = 3 (mm).+ Tong dien tch lo bang 9,77% dien tch mam.
+ Khoang cach gia hai tam lo bang 2,5 lanng knh lo (bo tr lo theo tam giac eu ).
+ Ty le be day mam va ng knh lo la 6/10 .+ Dien tch danh cho ong chay chuyen la 20%
dien tch mam .So lo tren 1 mam :
N =lo
mm
S
%.77,9 S=
22
003,0
5,0.0977,0.0977,0
=
l
t
d
D~2716 lo.
Vay: ta bo tr cac lo tren 1 mam thanh 51(hang), so
lo tren ng cheo la 66 lo.2 . o giam ap cua pha kh qua mot mam :o giam ap tong cong cua pha kh (tnh bang
mm.chat long ) la tong cac o giam ap cua pha khqua mam kho va cac o giam ap do pha long :
htl = hk + hl + hR (mm.chat long)Vi : + hk :o giam ap qua mam kho (mm.chat
long).+ hl : o giam ap do chieu cao lp chat long
tren mam(mm.chat long).
+hR : o giam ap do sc cang be mat(mm.chat long).
Trong thap mam xuyen lo ,gradien chieu cao mcchat long tren mam la khong ang ke nen co thebo qua .a . o giam ap qua mam kho :
o giam ap cua pha kh qua mam kho c tnh datren c s ton that ap suat do dong chay ot thu ,ot m va do ma sat khi pha kh chuyen ong qua lo.
29
113
824825826827
828
829
830
831
832833834
835836837838839840
841
842
843844845846847848849850851852
853854855
856857858859860861
114
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
L
G
o
o
L
G
o
ok
C
u
gC
vh
..0,51
..2.
2
2
2
2
=
= (mm.chat long)
Vi : + uo :van toc pha hi qua lo (m/s).+ G : khoi lng rieng cua pha hi (Kg/m3).+ L : khoi lng rieng cua pha long (Kg/m3).+ Co :he so orifice ,phu thuoc vao ty so tong
dien tch lo vi dien tch mam va ty so gia beday mam vi ng knh lo.
Ta co :mmS
Slo =0,0977 val
mm
d
=0,6 .Tra tai lieu
tham khao [1 trang 111] : Co = 0,745 oi vi mam phan cat :
+ Van toc pha hi qua lo : uo = 0977,0903,0
%77,9 =lv
=9,243(m/s).
+ Khoi lng rieng cua pha hi : G = ytb = 1,171(Kg/m3).
+ Khoi lng rieng cua pha long : L = xtb =821,25 (Kg/m3).
Suy ra o giam ap qua mam kho phan cat :
25,821
171,1.
745,0
243,9.0,51
2
2
=kh =10,683 (mm.chat long).
oi vi mam phan chng :+ Van toc pha hi qua lo : uo =
0977,0
903,0
%77,9
'=lv
=9,243
(m/s).+ Khoi lng rieng cua pha hi : G = ytb = 0,746
(Kg/m3).+ Khoi lng rieng cua pha long : L = xtb =
925,744 (Kg/m3).Suy ra o giam ap qua mam kho phan chng :
744,925
746,0.745,0
243,9.0,51' 2
2
=kh = 6,039 (mm.chat long).
b . o giam ap do chieu cao mc chat long trenmam :Phng phap n gian e c tnh o giam ap cua
pha hi qua mam do lp chat long tren mam hl la tchieu cao g chay tran hw , chieu cao tnh toan cua lpchat long tren g chay tran how va he so hieu chnhtheo kinh nghiem :
hl = .( hw + how ) , (mm.chat long)
Chon : + He so hieu chnh : = 0,6
30
117
862
863
864
865866867868
869
870
871
872873
874875
876877878
879
880
881
882
883884
885886887
888
889890891892893894
895
896
897
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
+ Chieu cao g chay tran : hw = 50 (mm)Chieu cao tnh toan cua lp chat long tren g chay
tran c tnh t phng trnh Francis vi g chay tranphang :
32
.4,43
=
w
Low
Lqh , (mm.chat long)
Vi : + qL : lu lng cua chat long (m3/ph).+ Lw :chieu dai hieu dung cua g chay tran (m).
Xac nh Lw :Dien tch danh cho ong chay chuyen la 20% dien
tch mam , nen ta co phng trnh sau :
.2,0sin180
.= o
o
o
nn
Vi : no :goc tam chan bi chieu dai oan Lw .
Dung phng phap lap ta c : no = 93o1222Suy ra : Lw = Dt . sin(no/2) = 363,305(mm) ~ 364 (mm) =
0,364 (m). Xac nh qL :
* Phan cat :25,821.60
8.41.60,5.973,2
.60
..==
xtb
D
L
MDRq
= 0,01412
(m3/ph).
Suy ra :3
2
364,0
01412,0.4,43
=owh = 4,978 (mm).
Vay :o giam ap do chieu cao mc chat longtren mam phan cat la:hl = 0,6.(50+4,978) = 32,987 (mm.chat long).
* Phan chng :744,925.60
189,18.608,63
'.60
.' '
1'
==xtb
tbG
L
MGq
= 0,02083
(m3/ph).
Suy ra :3
2
364,0
02083,0.4,43'
=
owh = 6,445 (mm).
Vay :o giam ap do chieu cao mc chat long
tren mam phan chng :hl = 0,6.(50+6,445) = 33,867 (mm.chat long).c . o giam ap do sc cang be mat :
o giam ap do sc cang be mat c xac nh theobieu thc :
lL
Rd
h.
.54,625
= , (mm.chat long)
Vi : + : sc cang be mat cua chat long(dyn/cm).
+ L : khoi lng rieng cua pha long (Kg/m3). Phan cat :
31
121
898899900901
902
903904905906907
908
909
910911912913
914
915
916
917918919
920
921
922
923
924925926927928
929
930931
932
933
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
* Khoi lng rieng cua pha long : L = xtb = 821,25(Kg/m3).
* ttb = 82,5oC ,tra tai lieu tham khao [4 (tap 1)], ta co :+ Sc cang be mat cua nc : N = 62,138
(dyn/cm).+ Sc cang be mat cua ru : R = 17,075(dyn/cm).
Suy ra :Sc cang be mat cua chat long phancat :
RN
RN
+=
.= 13,394 (dyn/cm).
Vay : o giam ap do sc cang be mat phancat la :
003,0.25,821
394,13.54,625=Rh = 3,401 (mm.chat long).
Phan chng :* Khoi lng rieng cua pha long : L = xtb = 925,744
(Kg/m3).* ttb = 93,25oC ,tra tai lieu tham khao [4 (tap 1)], ta
co :+ Sc cang be mat cua nc : N = 60,149
(dyn/cm).+ Sc cang be mat cua ru : R = 16,108
(dyn/cm).Suy ra :Sc cang be mat cua chat long phan
chng :
RN
RN
''
'.''
+= = 12,705 (dyn/cm).
Vay : o giam ap do sc cang be mat phanchng la :
003,0.744,925
705,12.54,625' =Rh = 2,862 (mm.chat long).
Tom lai : o giam ap tong cong cua pha kh qua
mot mam :+ Phan cat : htl = 10,683+32,987+3,401 = 47,071(mm.chat long).
hay htl = 47,071 . 10-3 . 9,81 . 821,25 = 379,226(N/m2).
+ Phan chng : htl = 6,039+33,867+2,862 = 42,768(mm.chat long).
hay htl = 42,768 . 10-3 . 9,81 . 925,744 = 388,400(N/m2).
Suy ra :Tong tr lc cua toan thap hay o giam ap
tong cong cua toan thap la :(xem o giam ap tong
32
125
934935936
937938
939940941942
943
944945
946
947
948949950951
952953
954955956957
958
959960
961
962
963964965966967968969970971972
973
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
cong cua pha kh qua mam nhap lieu bang o giamap tong cong cua pha kh qua mot mam phanchng )
htl = 42. htl + 11. htl = 42 . 379,226+11 . 388,400 =20199,9(N/m2).
33
129
974975976
977978
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
3 . Kiem tra ngap lut khi thap hoat ong :Chon khoang cach gia hai mam la hmam =250 (mm).Bo qua s tao bot trong ong chay chuyen, chieu cao
mc chat long trong ong chay chuyen cua mam xuyen
lo c xac nh theo bieu thc :hd = hw + how + htl + hd , (mm.chat long)Vi : hd : ton that thuy lc do dong long chay t
ong chay chuyen vao mam, c xac nh theo bieuthc sau :
2
'.100
.128,0
=
d
Ld
S
Qh , (mm.chat long)
trong o : + QL : lu lng cua chat long (m3/h).+ Sd : tiet dien gia ong chay chuyen va
mam, khi o :Sd = 0,8 . Smam = 0,8 . .0,252 = 0,1571 (m2)
Phan cat : QL = 60.qL = 60 . 0,01412 = 0,8472 (m3/h).
Suy ra :2
'1571,0.100
8472,0.128,0
=dh = 0,0004 (mm.chat long).
Vay : chieu cao mc chat long trong ong chaychuyen cua mam xuyen lo phan cat :
hd =50+4,978+47,071+0,0004 =102,0494(mm.chat long).
Kiem tra : hd = 102,0494 < 1252
250
2
mm ==h
(mm) : am
bao khi hoat ong cac mam phan cat se khong bngap lut.
Phan chng : QL = 60.qL = 60 . 0,02083 = 1,2498 (m3/h).
Suy ra :2
'1571,0.100
2498,1.128,0'
=dh = 0,0008 (mm.chat long).
Vay : chieu cao mc chat long trong ong chaychuyen cua mam xuyen lo phan chng :
hd =50+6,445+42,768+0,0008 =99,2138 (mm.chatlong).
Kiem tra : hd = 99,2138 < 1252
250
2
mm ==h (mm) : am bao
khi hoat ong cac mam phan chng se khong bngap lut.Vay : khi hoat ong am bao thap se khong b
ngap lut.Chieu cao cua than thap :Hthan =Ntt .(hmam+ mam ) +
0,8=53.(0,250+0,0018) +0,8 =14,2(m).
Chieu cao cua ay va nap : H = Hn =ht +hg=0,125+0,025=0,150(m).
34
133
979980981982983984985986987
988
989990991
992993
994
995996997998
999
100010011002
1003
1004100510061007
1008
1009101010111012
10131014101510161017
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
(Xem phan (III.2) : ay va Nap thiet b ).Chieu cao cua thap : H = Hthan + H + Hn = 14,5(m).
35
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10181019
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
III . TNH TOAN C KH CUA THAP :1 . Be day than thap :
V thap chng cat hoat ong ap suat thng nen tathiet ke than hnh tru bang phng phap han giap moi
(phng phap ho quang ). Than thap c ghep vi nhaubang cac moi ghep bch.e am bao chat lng cua san pham va kha nang
an mon cua etylic oi vi thiet b, ta chon vat lieu chetao than thap la thep khong g ma X18H10T. Ap suat tnh toan :
Thap lam viec ap suat kh quyen, nen ta chon apsuat tnh toan :
Ptt =Pcl + htl , (N/mm2)Vi : Pcl : ap suat thuy tnh do chat long ay
(N/mm2).Chon ap suat tnh toan sao cho thap hoat ong
ieu kien nguy hiem nhat ma van an toan nen :
Pcl = x .g.H =2
'xtbxtb + .g.H=2
744,92525,821 +. 9,81 .
14,5=124250,58 (N/m2).
Suy ra : Ptt = 124250,58 + 20199,9 = 144450,48(N/m2)~0,14446(N/mm2).
0.25=25N/cm2
Nhiet o tnh toan :Chon nhiet o tnh toan : ttt = tay = 100oC .Tra tai lieu tham khao [5], ng suat tieu chuan oivi thep X18H10T :
[ ]* = 142 (N/mm2).oi vi ru he so hieu chnh : = 1Vay : ng suat cho phep : [ ] = .[ ]* = 142 (N/mm2).
Xac nh be day than chu ap suat trong :Ta chon phng phap che tao than la phng phap
han ho quang ien bang tay nen he so ben moi han : h = 0,9
Xet ty so :[ ]
95,0.25.0
142. =h
ttP
=539.6 > 25,do o, be day
tnh toan cua than c tnh theo cong thc sau :
[ ] 95,0.142.225.0.2200
..2
.' ==
h
ttt
t
PDS
= 2 (mm).
Suy ra : be day thc cua than : St = St + C ,(mm).Trong o : C :he so bo sung be day, C = Ca + Cb + Cc
+ Co
36
141
1020
102110221023
10241025102610271028
102910301031
10321033
103410351036
1037
10381039104010411042
1043104410451046
1047
1048
1049
10501051
10521053
1054
1055
1056
10571058
1059
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Vi : + Ca : he so bo sung do an mon hoa hoc,phu thuoc vao toc o an mon cua chat long.Chon toc o an mon cua ru la 0,1(mm/nam),thiet b hoat ong trong 20 nam, doo Ca = 2 mm.
+Cb : he so bo sung do bao mon c hoc, chonCb = 0.
+Cc : he so bo sung do sai lech khi che tao,chon Cc = 0.
+Co : he so bo sung qui tron, chon Co =0,7174(mm).
Suy ra : C = 2 + 0 + 0 + 0,7174 = 2,7174 (mm).Vay : St = 0,2826 + 2,7174 = 3 (mm).5
* Kiem tra cong thc tnh toan vi St = 3 (mm) :
220025=
t
at
D
CS
= 0,002 < 0,1 : ung.
* Kiem tra ap suat tnh toan cho phep :
[ ] [ ] ( )( )
( )
( )252200
25.95,0.142.2...2
+
=+
=att
ath
ttCSD
CSP
=0,5102 > Ptt :
ung.Vay : Be day thc cua than la St = 3 (mm).
2 . ay va nap thiet b :Chon ay va nap co dang la ellipise tieu chuan, co
g bang thep X18H10T.
Nhan thay: cong thc tnh toan be day than, ay vanap chu ap suat trong la nh nhau. Nen chon be day cuaay va nap la S = Sn = 3 (mm).
Cac kch thc cua ay va nap ellipise tieu chuan, cog(tai lieu tham khao [4(tap 2)]:+ ng knh trong: Dt = 500 (mm).+ ht =125 (mm).+ Chieu cao g: hg = h = 25 (mm).+Dien tch be mat trong: Say = 0,31 (m2).
3 . Bch ghep than, ay va nap :Mat bch la bo phan quan trong dung e noi cac
phan cua thiet b cung nh noi cac bo phan khac vithiet b. Cac loai mat bch thng s dung:
37
145
10601061106210631064106510661067106810691070107110721073
1074
1075
1076
10771078
107910801081
1082108310841085108610871088108910901091
1092109310941095
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
+ Bch lien: la bo phan noi lien vi thiet b (han,uc va ren). Loai bch nay chu yeu dung thiet b lamviec vi ap suat thap va ap suat trung bnh.
+ Bch t do: chu yeu dung noi ong dan lam viec nhiet o cao, e noi cac bo bang kim loai mau va hpkim cua chung, ac biet la khi can lam mat bch bangvat lieu ben hn thiet b.
+ Bch ren: chu yeu dung cho thiet b lam viec apsuat cao.
Chon bch c ghep than, ay va nap lam bangthep X18H10T, cau tao cua bch la bch lien khong co.
Theo tai lieu tham khao [4 (tap 2)- trang 417], ng viDt =500(mm) va ap suat tnh toan Ptt = 0,14446(N/mm2) tachon bch co cac thong so sau :
Dt D Db D1 h Bu long
db Z
(mm)(cai)
500 630 580 550 20 20 16Theo tai lieu tham khao [4 (tap 2)- trang 170], chon so mam
gia hai mat bch la 4 mam.Vay, so bch ghep than-ay-napla (15.2) bch.
o kn cua moi ghep bch chu yeu do vat em quyetnh. em lam bang cac vat lieu mem hn so vi vat lieubch. Khi xiet bu long, em b bien dang va ien ay len caccho go ghe tren be mat cua bch. Vay, e am bao o kncho thiet b ta chon em la day amiang, co be day la3(mm).4 . ng knh cac ong dan Bch ghep cac
ong dan :Bch c lam bang thep CT3 , cau tao cua bch la bch
lien khong co.
38
149
10961097109810991100110111021103110411051106
1107110811091110
111111121113111411151116111711181119
1120
112111221123
150
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
a . V tr nhap lieu :Suat lng nhap lieu: GF = 1000 (Kg/h).Khoi lng rieng cua chat long nhap lieu, tra tai
lieu tham khao [4 (tap 1)] tF = 86,5oC va %12,22=Fx : F = 920,1 (Kg/m3).
Lu lng chat long nhap lieu i vao thap:F
FF
GQ
= =
1,087 (m3/h).Chon van toc chat long nhap lieu (t chay t bon
cao v vao mam nhap lieu): vF = 0,2 (m/s).ng knh ong nhap lieu: dF =
044,02,0..3600
087,1.4
..3600
.4==
F
F
v
Q(m).
Suy ra: chon ng knh ong nhap lieu: dF = 0,050(m).
Tai lieu tham khao [4 (tap 2)], chon chieu dai oanong noi e ghep mat bch: lF = 100 (mm).
Cac thong so cua bch ghep ong dan nhap lieu:Dt Db Dn D D1 h Bu long
db Z
(mm)
(cai)
50 110 57 140 90 12 12 4
b . Ong hi nh thap:Suat lng hi nh thap: gd = 933,662 (Kg/h).Khoi lng rieng cua hi nh thap c tnh theo
cong thc (xac nh tD = 78,5oC va yD = 0,856):
( )[ ]( )273.4,22
273.18.1.46
++
=D
DDh
t
yy = 1,453 (Kg/m3).
Lu lng hi ra khoi thap:h
d
gQh = = 642,483 (m3/h).
Chon van toc hi nh thap: vh = 25 (m/s).
39
153
11241125112611271128
1129
1130
1131113211331134
1135
11361137113811391140
11411142114311441145
1146
1147
1148
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
ng knh ong dan hi: dh = 095,025..3600
483,642.4
..3600
.4==
h
h
v
Q
(m).Suy ra: chon ng knh ong dan hi: dh = 0,100 (m).
Tai lieu tham khao [4(tap 2)], chon chieu dai oanong noi e ghep mat bch: lh = 120 (mm).Cac thong so cua bch ghep ong dan hi nh
thap:Dt Db Dn D D1 h Bu long
db Z
(mm)
(cai)
100 170 108 205 148 14 16 4
c . Ong hoan lu:
Suat lng hoan lu: Ghl =D.MD.R=5,600 . 41,8 . 2,973=695,864 (Kg/h).Khoi lng rieng cua chat long hoan lu, tra tai lieu
tham khao [4 (tap 1)] tD = 86,5oC va %5,93=Dx : hl = 771,55 (Kg/m3).
Lu lng chat long hoan lu:hl
hl
hl
GQ
= = 0,902 (m3/h).
Chon van toc chat long hoan lu (t chay t bophan tach long ngng tu vao thap): vhl = 0,15 (m/s).
ng knh ong hoan lu: dhl =
046,015,0..3600
902,0.4
..3600
.4==
vhl
Qhl (m).
Suy ra: chon ng knh ong hoan lu: dhl = 0,050 (m).Tai lieu tham khao [4 (tap 2)], chon chieu dai oan
ong noi e ghep mat bch: lhl = 100 (mm).Cac thong so cua bch ghep ong dan hoan lu:
Dt Db Dn D D1 h Bu long
db Z
(mm)
(cai)
50 110 57 140 90 12 12 4
d . Ong dan hi vao ay thap:Suat lng hi vao ay thap: g1 = 391,008 (Kg/h).Khoi lng rieng cua hi vao ay thap c tnh theo
cong thc (xac nh tW = 100oC va yW = 0,018):
( )[ ]( )273.4,22
273.18.1.46
++
=W
WW
dht
yy = 0,605 (Kg/m3).
Lu lng hi ra khoi thap: hd1'
g
Qhd = = 646,722 (m3
/h).
40
157
1149
11501151
1152115311541155
1156
1157115811591160
1161
1162
116311641165
1166
1167116811691170
11711172117311741175
1176
1177
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Chon van toc hi vao ay thap: vhd = 25 (m/s).
ng knh ong dan hi: dhd = 096,025..3600
722,646.4
..3600
.4==
hl
hl
v
Q
(m).
Suy ra: chon ng knh ong dan hi: dhd = 0,100 (m).Tai lieu tham khao [4 (tap 2)], chon chieu dai oanong noi e ghep mat bch: lhd = 120 (mm).
Cac thong so cua bch ghep ong dan hi vao aythap:Dt Db Dn D D1 h Bu long
db Z
(mm)
(cai)
100 170 108 205 148 14 16 4
e . Ong dan chat long ay thap:Suat lng chat long vao noi un:G1 =63,608.MG=63,608 .18,189 =1156,973 (Kg/h).
Khoi lng rieng cua chat long chat long vao noiun, tra tai lieu tham khao [4(tap 1)] tW = 100oC vax1=0,0067: L = 898,257 (Kg/m3).
Lu lng chat long vao noi un:L
L
GQ
1'= = 1,288
(m3/h).Chon van toc chat long vao noi un (chat long t
chay vao noi un):vL = 0,2 (m/s).
ng knh ong dan chat long: dL=
2,0..3600
288,1.4
..3600
.4
=
L
L
v
Q=0,048(m).
Suy ra: chon ng knh ong dan: dL = 0,050 (m).Tai lieu tham khao [4 (tap 2)], chon chieu dai oan
ong noi e ghep mat bch: lL = 100 (mm).Cac thong so cua bch ghep ong dan chat long
ay thap:Dt Db Dn D D1 h Bu long
db Z
(mm)
(cai)
50 110 57 140 90 12 12 4
f . Ong dan chat long t noi un (san phamay):
Suat lng san pham ay: GW = W.MW = 42,477 .18,032= 765,939(Kg/h).
Khoi lng rieng cua san pham ay, tra tai lieutham khao [4 (tap 1)]
41
161
1178
1179
1180
11811182118311841185
11861187118811891190
1191
1192
11931194
119511961197
1198
1199120012011202
1203
1204120512061207
12081209
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
tW= 100oC va xW=0,0011: W = 957,726 (Kg/m3).
Lu lng san pham ay:W
WW
GQ
= = 0,800 (m3/h).
Chon van toc san pham ay (chat long t chay): vW
= 0,12 (m/s).ng knh ong dan san pham ay: dW=
12,0..3600
800,0.4
..3600
.4
=
W
W
v
Q=0,049(m).
Suy ra: chon ng knh ong dan: dW = 0,050 (m).Tai lieu tham khao [4 (tap 2)], chon chieu dai oan
ong noi e ghep mat bch: lW = 100 (mm).Cac thong so cua bch ghep ong dan san pham
ay:Dt Db Dn D D1 h Bu long
db Z
(mm)
(cai)
50 110 57 140 90 12 12 4
5 . Tai treo va chan : Tnh trong lng cua toan thap:
Khoi lng cua mot bch ghep than: (thep X18H10T: X18H10T = 7900 (Kg/m3)).
m1 = ( ) ( ) 7900.02,05,063,0.4
...4
22
1018
22 =
THXt hDD =
18,144(Kg).Khoi lng cua mot mam: (thep X18H10T: X18H10T =
7900 (Kg/m3)).
m2 = THXmmtD 10182
.7,0...4
=4
.0,52.0,0018.0,7.7900
=1,955(Kg).Khoi lng cua than thap:
m3 =4
.(D2ng D2t).Hthan . X18H10T = ( ) 7900.2,14.5,0506,0.
4
22
= 531,808 (Kg).Khoi lng cua ay (nap) thap:
m4 = Say . ay . X18H10T = 0,31 . 0,003 . 7900 = 7,347(Kg).
Khoi lng cua toan thap: m =30.m1+53.m2+m3+2.m4=1193,537(Kg).
Suy ra trong lng cua toan thap: P = m.g = 11708,598(N).
Chan thap:
42
165
1210
1211
1212
12131214
1215
12161217121812191220
1221
12221223
1224
1225
122612271228
1229
12301231
1232
1233
1234123512361237123812391240
1241
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Chon chan : thap c tren bon chan. Taitrong cho phep tren mot chan: Gc =
4
598,11708
4=P = 0,293.104 (N).
e am bao o an toan cho thiet b, ta chon: Gc =
0,5.104 (N).
T
ruc
thiet
b
Theo aythiet b
Cac kch thc cua chan : (tnh bang mm)
L B B1 B2 H h s l d
160 110 135 195 240 145 10 55 23
Tai treo:
Chon tai treo: tai treo c gan tren than thap e gicho thap khoi b dao ong trong ieu kien ngoai canh.Ta chon bon tai treo, tai trong cho phep tren mot tai treola Gt = 0,293.104 (N).
e am bao o an toan cho thiet b, ta chon: Gt =0,5.104 (N).
Chon tam lot tai treo khi ghep vao than co kch thcsau:+ Chieu dai tam lot: H = 260 (mm).+ Chieu rong tam lot: B = 140 (mm).
+Be day tam lot la 6 (mm).
43
169
12421243
1244
1245
1246
12471248
1249
1250125112521253125412551256125712581259
1260
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Cac kch thc cua tai treo: (tnh bang mm)L B B1 H S l a d
100 75 85 155 6 40 15 18
44
173
12611262
12631264126512661267
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
CHNG IV: TNH TOAN THIET BTRUYEN NHIET- THIET BPHU.
I . CAC THIET B TRUYEN NHIET:Can bang nhiet lng cho toan thap chng cat:
QF + Q = QW + QD + Qnt + Qm (IV.1)Trong o:
Qnt: nhiet lng ngng tu do hi san pham nhngng tu thanh long. Chon hi san pham nhngng tu hoan toan thanh long.
Qnt = D.(R+1).MD . rD , (KJ/h).Xac nh rD (an nhiet hoa hi cua san pham
nh):Tra tai lieu tham khao [4 (tap 1)], tD = 78,5oC taco:An nhiet hoa hi cua nc: rN = 2346,253 (KJ/kg).An nhiet hoa hi cua ru: rR = 848,084 (KJ/kg).
Suy ra: rD = rR . Dx +(1- Dx ).rN = 848,084.0,935+(1-0,935).2346,253
= 945,465 (KJ/kg).Vay: Qnt =5,600 .(2,973+1) .41,8 .945,465=879211,642 (KJ/h).
QF : nhiet lng do hon hp ru nhap lieu mangvao thap.QF = GF .HF =GF .cF .(tF to ) ,(KJ/h).
Chon nhiet o chuan: to = 20oC.
25,532
205,86
2=
+=
+ oF tt oC , tra tai lieu tham khao [4
(tap 1)], ta co nhiet dung rieng cua ru: cR=2882,25 (J/kg.o).
Suy ra: cF = Fx .cR +(1- Fx ).4186=22,12%.2882,25+(1-22,12%).4186 =
4055,625(J/kg.o).Vay: QF = 1000.4055,625.(86,5-20) = 269699,063(KJ/h).
QW : nhiet lng do san pham ay mang ra tnoi un.
QW = GW .HW =W.MW.cW .(tW to ) ,(KJ/h).Chon nhiet o chuan: to = 20oC.Do san pham ay cha nhieu nc nen nhiet
dung rieng cua san pham ay co the tnh ganung theo cong thc sau:
45
177
1268
1269
1270
1271127212731274127512761277127812791280
128112821283128412851286128712881289
1290129112921293
1294
1295129612971298
1299130013011302130313041305130613071308
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
cW = (1- Wx ).4186=(1- 0,0029).4186= 4173,861(J/kg.o).Vay: QW = 42,477. 18,032 .4173,861 .(100-20)=255753,898(KJ/h).
QD : nhiet lng do san pham nh mang ra tbo phan tach hoan lu.
QD = GD .HD =D.MD .cD .(tD to ) ,(KJ/h).Chon nhiet o chuan: to = 20oC.
25,492
205,78
2=
+=
+ oD tt oC , tra tai lieu tham khao [4
(tap 1)], ta co nhiet dung rieng cua ru: cR=2830,25 (J/kg.o).
Suy ra: cD = Dx .cR +(1- Dx ).4186=0,935.2882,25+(1-0,935).4186 =
3033,613(J/kg.o).Vay: T (IV.1), ta c:QF = 5,600 .41,8 .3033,613 .(78,5-20) =41537,988
(KJ/h). Qm : nhiet lng ton that ra moi trng xung
quanh.Chon: Qm = 0,05.Q
Vay: nhiet lng can cung cap cho noi un aythap:
Q =95,0
1.(QW + QD + Qnt QF )
=95,0
1(255753,898+41537,988+879211,642-
269699,063)= 954531,016 (KJ/h) = 265,148 (KW).
Chon: + Nhiet o nguyen lieu ban au: tF = 28oC.+ Nhiet o san pham nh sau khi lam nguoi: tD= 35oC.+ Nhiet o san pham ay sau khi trao oi nhiet
vi nguyen lieu ban au: tW = 60oC.
1 . Thiet b ngng tu san pham nh:Chon thiet b ngng tu vo ong loai TH at nam ngang.Ong truyen nhiet c lam bang thep X18H10T, kch
thc ong: 25x2, chieu dai ong la L = 1,5 (m).Chon nc lam lanh i trong ong vi nhiet o au: t1
= 28oC, nhiet o cuoi: t2 = 40oC.Cac tnh chat ly hoc cua nc lam lanh c tra
tai lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh
ttbN =2
21 tt + =34oC:
+ Nhiet dung rieng: cN = 4,181 (KJ/kg.o).
46
181
13091310131113121313131413151316
1317
1318131913201321
132213231324132513261327132813291330
1331
1332
1333133413351336133713381339
13401341134213431344134513461347
1348
1349
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
+ Khoi lng rieng: N = 994,4 (Kg/m3).+ o nht ong lc: N = 0,7371.10-3 (N.s/m2).+ He so dan nhiet: N = 0,6242 (W/moK).
a . Suat lng nc can dung e ngng tu san
pham nh:GN =
)2840.(181.4.3600
642,879211
).(.3600 12 =
ttcQ
N
nt = 4,868 (Kg/s).
b . Xac nh be mat truyen nhiet :Be mat truyen nhiet c xac nh theo phng trnh
truyen nhiet:
Ftb =log. tK
Qnt
,(m2) (IV.2).
Vi: + K : he so truyen nhiet.+ tlog : nhiet o trung bnh logarit.
Xac nh tlog :Chon kieu truyen nhiet ngc chieu, nen:
229.44
405,78
285,78
)405,78()285,78(log =
=
Ln
t(oK).
Xac nh he so truyen nhiet K:He so truyen nhiet K c tnh theo cong thc:
R
t
N
r
K
11
1
++=
,(W/m2.oK) (IV.3).
Vi: + N : he so cap nhiet cua nc trong ong(W/m2.oK).
+ R : he so cap nhiet cua hi ngng tu(W/m2.oK).
+ rt : nhiet tr cua thanh ong va lp cau.* Xac nh he so cap nhiet cua nc trong ong:
Chon van toc nc i trong ong: vN = 0,4 (m/s).So ong trong mot ng nc:
19~75,0.021,0.
4
.4,994
868,4
..
4
. 22 == NtrNN
vd
G
n (ong).
Chuan so Reynolds :
86,2124710.7371,0
4,994.021,0.75,0.Re
3
. === N
NtrNN
dv
> 104 : che
o chay roi, cong thc xac nh chuan soNusselt co dang:
25,043,08,0 )Pr
Pr.(PrRe..021,0
w
N
NNlNNu =
Trong o:
47
185
1350
1351
13521353
13541355
135613571358
1359
1360
1361
13621363
1364
13651366
1367
13681369
13701371
1372137313741375
1376
1377
1378
13791380
1381
1382
186
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
+ l : he so hieu chnh phu thuoc vao ReN vaty le chieu dai ong vi ng knh
ong:ReN=21247,86va 50021,05,1
>=trd
L,nen l =1.
+ PrN : chuan so Prandlt cua nc 34
o
C, nenPrN = 5.+ Prw : chuan so Prandlt cua nc nhiet o
trung bnh cua vach.
Suy ra: 25,0Pr
707,181
w
NNu =
He so cap nhiet cua nc trong ong:
N = 25,025,0Pr
024,5401
021,0.Pr
6242,0.707,181.
NNtr
NN
d
Nu==
Nhiet tai pha nc lam lanh:
)34(Pr
024,5401).(
225,02== w
N
tbNwNN tttq (W/m2) (IV.4).
Vi tw2 : nhiet o cua vach tiep xuc vi nc(trong ong).
* Nhiet tai qua thanh ong va lp cau:
t
ww
tr
ttq
= 21 , (W/m2).
Trong o:+ tw1 : nhiet o cua vach tiep xuc vi ru
(ngoai ong).
+ ct
t
trr +=
Be day thanh ong: t = 2 (mm).He so dan nhiet cua thep khong g: t =
17,5 (W/moK).Nhiet tr trung bnh cua lp ban trong ong
vi nc sach:rc = 1/5000 (m2.oK/W).
Suy ra: rt = 1/3181,818 (m2
.o
K/W).Vay: qt = 3181,818.(tw1-tw2) (IV.5)* He so cap nhiet cua hi ngng tu:
25,0
1
4
1
23
)5,78()..(
...725,0
wngwDR
RRRR
t
A
dtt
r
=
=
at: A= 423
.
...725,0
ngR
RRR
d
r
vi [rR]=[J/kg].
An nhiet ngng tu: rR = rD = 945,465 (KJ/
;kg).Nhiet tai ngoai thanh ong:
48
189
13831384
1385
1386138713881389
1390
1391
1392
1393
1394
139513961397
1398
13991400
1401
1402
1403
14041405140614071408
140914101411
1412
1413
1414
14151416
190
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
qR = R.(78,5-tw1) = A.(78,5-tw1)0,75 (IV.6).T (IV.4), (IV.5), (IV.6) ta dung phng phap lap e xac
nh tw1, tw2 :Chon: tw1 = 53,7oC :Cac tnh chat ly hoc cua ru ngng tu c tra tai
lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh ttbD
= 1,662
7,535,78
2
1 =+
=+ wD tt oC:
+ Khoi lng rieng: R = 767,68 (Kg/m3).+ o nht ong lc: R = 0,6018.10-3 (N.s/m2).+ He so dan nhiet: R = 0,2073 (W/moK).
Khi o: A = 3090,099T (IV.6): qR = 3090,099.(78,5-53,7)0,75 = 34340,859
(W/m2).
Xem nhiet tai mat mat la khong ang ke: qt = qR=34340,859 (W/m2).
T (IV.5), ta co: tw2 = tw1-818,3181
tq =42,907oC
Suy ra: ttbw =2
21 ww tt + = 304,482
907,427,53=
+ oC
Tra tai lieu tham khao [4 (tap 1)], Prw = 3,672
T (IV.4): qN = 167,34752)34907,42.(672,3
024,540125,0
= (W/m2).
Kiem tra sai so:
=859,34340
859,34340167,34752 =
R
RN
q
qq=1,2% < 5% :
thoa.Vay: tw1 = 53,7oC va tw2 = 42,907oC.
Khi o: 669,3901672,3
024,540125,0
==N
(W/m2.oC).
712,1384)7,535,78(
099,309025,0
=
=R (W/m2.oC).
T (IV.3):
540,773
712,1384
1
818,3181
1
669,3901
1
1=
++
=K
(W/m2.oC).T (IV.2), be mat truyen nhiet trung bnh:
229,44.540,773.3600
1000.642,879211=tbF = 7,1384 (m2).
Suy ra chieu dai ong truyen nhiet :
L=2,5
2
021,0025,0.19.
1384,7=
+=
(m).
49
193
141714181419142014211422
1423
1424
1425
1426142714281429
14301431
1432
1433
1434
1435
1436
1437
14381439
1440
1441
1442
14431444
1445
1446
1447
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
So vi L = 1,5(m) th so ng nc la 4~5,1
2,5'=
L
L
(ng nc).Khi o so ong tang len 4 lan: n=19.4 =76 (ong) ~
chon n=91(ong).
* Kiem tra he so cap nhiet cua ru khi co ke ens anh hng cua s sap sep, bo tr ong. Chon cachxep ong thang hang, bo tr theo dang luc giaceu,vay vi 91 ong th ta sep c 9 hang.
So ong trung bnh trong 1 hang: 11,109
91= , tra tai lieu
tham khao II, ta co tb = 0,58.Khi o: R = 0,58.1384,712 = 803,133 (W/m2.oC).Tnh lai he so truyen nhiet K t CT(IV.3), ta co: K =
550,749 (W/m2.oC).
Suy ra: be mat trung bnh: 026,10229,44.749,550.3600
1000.642,879211==tbF
(m2).Khi o: chieu dai ong truyen nhiet:
L=).(403,1
2
021,0025,0.91.
026,10m=
+
< 1,5(m) : thoa.
Vay : Thiet b ngng tu san pham nh la thiet btruyen nhiet vo ong gom n=91(ong), dai L=1,5(m).
Ong c bo tr theo hnh luc giac eu. Nen ta coso ong tren ng cheo hnh luc giac: b = 9(ong). Chonbc ngang gia hai ong: t = 1,4.dng = 1,4.0,025 = 0,035 (m).
ng knh vo thiet b: Dv = t.(b-1)+4.dng = 0,035(9-1)+4.0,025
= 0,380(m).2 . Thiet b lam nguoi san pham nh:
Chon thiet b lam nguoi san pham nh la thiet btruyen nhiet ong long ong. Ong truyen nhiet c lambang thep X18H10T, kch thc ong trong: 16x1,6 ; kch
thc ong ngoai: 25x2,5.Chon: + Nc lam lanh i trong ong 16x1,6 (ong trong)vi nhiet o au: t1 = 28oC, nhiet o cuoi: t2 = 40oC.
+ San pham nh i trong ong 25x2,5 (ong ngoai)vi nhiet o au:tD = 78,5oC, nhiet o cuoi: tD = 35oC.
Cac tnh chat ly hoc cua nc lam lanh c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh
ttbN =2
21 tt + =34oC:
+ Nhiet dung rieng: cN = 4,181 (KJ/kg.o).
+ Khoi lng rieng: N = 994,4 (Kg/m3).
50
197
1448
144914501451
1452145314541455
1456
1457
145814591460
1461
14621463
1464
14651466146714681469147014711472
1473147414751476
1477147814791480148114821483
1484
1485
1486
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
+ o nht ong lc: N = 0,7371.10-3 (N.s/m2).+ He so dan nhiet: N = 0,6242 (W/moK).
Cac tnh chat ly hoc cua san pham nh c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh
ttbD = 75,562 355,782'
=+=+ DDtt
oC:+ Nhiet dung rieng: cD= 3014,63 (J/kg.o).+ Khoi lng rieng: D = 775,95 (Kg/m3).+ o nht ong lc: D = 0,6988.10-3 (N.s/m2).+ He so dan nhiet: D = 0,2029 (W/moK).
a . Suat lng nc can dung e lam mat sanpham nh:
Suat lng san pham nh:GD = D.MD = 5,600.41,8 = 234,08 (Kg/h) = 0,065 (Kg/s).
Lng nhiet can tai:Qt = GD.cD.(tD-tD) = 0,065.3014,63.(78,5-35) =8526(J/s)
=8,526(KJ/s).Suat lng nc can dung:
GN =)2840.(181.4
526,8
).( 12 =
ttcQ
N
D = 0,170 (Kg/s).
b . Xac nh be mat truyen nhiet :Be mat truyen nhiet c xac nh theo phng trnh
truyen nhiet:
Ftb = log. tKQ
t
,(m2) (IV.7).Vi: + K : he so truyen nhiet.
+ tlog : nhiet o trung bnh logarit. Xac nh tlog :
Chon kieu truyen nhiet ngc chieu, nen:
478,18
2835
405,78
)2835()405,78(log =
=
Ln
t(oK).
Xac nh he so truyen nhiet K:
He so truyen nhiet K c tnh theo cong thc:
D
t
N
r
K
11
1
++=
,(W/m2.oK) (IV.8).
Vi: + N : he so cap nhiet cua nc trong ong(W/m2.oK).
+ D : he so cap nhiet cua san pham nh(W/m2.oK).
+ rt : nhiet tr cua thanh ong va lp cau.
* Xac nh he so cap nhiet cua san pham nh ong ngoai:
51
201
1487
148814891490
1491
1492
1493
1494
14951496149714981499
1500150115021503
1504
150515061507
1508
1509
1510
15111512
1513
1514
1515
1516
15171518
15191520
152115221523
202
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Van toc cua san pham nh i trong ong ngoai:
741,0)016,002,0.(
4.
95,775
065,0
)..(
4.
2222=
=
=
ngtrD
DD
dD
Gv (m/s).
ng knh tng ng: dtd = Dtr dng = 0,02- 0,016 =
0,004 (m).Chuan so Reynolds :
24,329110.6988,0
95,775.004,0.651,0.Re
3
. === D
DtdDD
dv
> 2320 : che
o qua o, cong thc xac nh chuan so Nusseltco dang:
25,0
1
43,0)
Pr
Pr.(Pr..
w
D
DlD CNu =
Trong o:
+ l : he so hieu chnh phu thuoc ty le chieudai ong vi ng knh ong1, chon l =1.+ C : he so phu thuoc vao chuan so Reynolds,
ReD = 3291,24 nenC = 7,252.
+ PrD : chuan so Prandlt cua san pham nh
56,75oC, nen2029,0
63,3014.10.6988,0.Pr
3
==D
DDD
c
=
10,383.+ Prw1 : chuan so Prandlt cua san pham nh
nhiet o trung bnh cua vach.Suy ra: 25,0
1Pr
610,35
w
DNu =
He so cap nhiet cua san pham nh trong ongngoai:
D = 25,01
25,0
1 Pr
339,1806
004,0.Pr
2029,0.610,35.
wwtd
DD
d
Nu==
Nhiet tai pha san pham nh:
)75,56(Pr
339,1806
).( 125,01
1 ww
wtbDDD tttq == (W/m2
) (IV.9).Vi tw1 : nhiet o cua vach tiep xuc vi san
pham nh (ngoai ong nho).* Nhiet tai qua thanh ong va lp cau:
t
ww
tr
ttq
= 21 , (W/m2).
Trong o:+ tw2 : nhiet o cua vach tiep xuc vi nc
(trong ong nho).
52
205
1524
1525
1526
15271528
1529
15301531
1532
1533
153415351536153715381539
1540
15411542
1543
1544
15451546
1547
1548
1549155015511552
1553
155415551556
206
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
+ 21 rrrt
t
t ++=
Be day thanh ong: t = 1,6 (mm).He so dan nhiet cua thep khong g: t = 17,5
(W/mo
K). Nhiet tr trung bnh cua lp ban trong ong vinc sach:
r1 = 1/5000 (m2.oK/W).Nhiet tr lp cau pha san pham nh: r2 =
1/5000 (m2.oK/W).Suy ra: rt = 1/2034,884 (m2.oK/W).
Vay: qt = 2034,884.(tw1-tw2) (IV.10).* Xac nh he so cap nhiet cua nc trong ong
nho:
Van toc nc i trong ong:329,1
0128,0.
4.
4,994
170,0
.
4.
22===
trN
NN
d
Gv (m/s).
Chuan so Reynolds :
04,2294110.7371,0
4,994.0128,0.329,1.Re
3
. === N
NtrN
N
dv
> 104 : che
o chay roi, cong thc xac nh chuan so Nusseltco dang:
25,0
2
43,08,0)
Pr
Pr.(PrRe..021,0
w
NNNlNNu =
Trong o:+ l : he so hieu chnh phu thuoc vao ReN va
ty le chieu dai ong vi ng knhong:ReN=22941,04,chon l =1.
+ PrN : chuan so Prandlt cua nc 34oC, nenPrN = 5.
+ Prw2 : chuan so Prandlt cua nc nhiet otrung bnh cua vach.
Suy ra: 25,02Pr
204,193
w
NNu =
He so cap nhiet cua nc trong ong:
N = 25,02
25,0
2 Pr
714,9421
0128,0.Pr
6242,0.204,193.
wwtr
NN
d
Nu==
Nhiet tai pha nc lam lanh:
)34(Pr
714,9421).( 225,0
2
2 == ww
tbNwNN tttq (W/m2) (IV.11).
Chon: tw1 = 42,65oC :
53
209
1557
1558
1559
156015611562156315641565
1566156715681569
1570
1571
1572
1573
15741575
1576
1577
15781579
15801581158215831584
1585
1586
1587
1588
1589
1590
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Cac tnh chat ly hoc cua san pham nh c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet otw1=42,65oC:
+ Nhiet dung rieng: cR= 2841,64 (J/kg.o).+ o nht ong lc: R = 0,9049.10-3 (N.s/m2).+ He so dan nhiet: R = 0,1966 (W/moK).
Khi o xem:Prw1 ~ 081,131966,0
64,2841.10.9049,0. 3==
R
RR c
T (IV.9): qD = 391,13392)65,4275,56.(081,13
339,180625,0
= (W/m2).
Xem nhiet tai mat mat la khong ang ke: qt = qD=13392,391 (W/m2).
T (IV.10), ta co: tw2 = tw1-884,2034
tq =36,069oC
Suy ra: ttbw =2
21 ww tt + = 360,392
069,3665,42 =+ oC
Tra tai lieu tham khao [4 (tap 1)], Prw2 = 4,386
T (IV.11): qN = 483,13470)34069,36.(386,4
714,942125,0
= (W/m2).
Kiem tra sai so:
=391,13392
391,13392483,13470 =
D
DN
q
qq=0,58% < 5% :
thoa.Vay: tw1 = 42,65oC va tw2 = 36,069oC.
Khi o: 625,6510386,4
714,942125,0
==N
(W/m2.oC).
815,949081,13
339,180625,0
==D
(W/m2.oC).
T (IV.8):977,588
815,949
1
884,2034
1
625,6510
1
1=
++=K
(W/m2.oC).T (IV.7), be mat truyen nhiet trung bnh:
478,18.977,588
1000.526,8
=tbF = 0,7834 (m2
).Suy ra chieu dai ong truyen nhiet :
L317,17
2
0128,0016,0.
7834,0=
+=
(m).
Chon: L = 20(m),(d tr khoang 15%).
Kiem tra: 505,15620128,0
20>==
trd
Lth l = 1: thoa.
Vay: thiet b lam mat san pham nh la thiet btruyen nhiet ong long ong vi chieu dai ong
54
213
1591159215931594
1595
1596
1597
1598
15991600
1601
1602
1603
1604
1605
1606
16071608
1609
1610
1611
16121613
16141615
1616
1617
1618
16191620
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
truyen nhiet L = 20(m), chia thanh 10 day, moi daydai 2 (m).
3 . Noi un gia nhiet san pham ay:Chon noi un gia nhiet san pham ay la noi un
Kettle, ong truyen nhiet c lam bang thep X18H10T,kch thc ong 25x2.Chon hi ot la hi nc 2 at, i trong ong 25x2. Tra tai
lieu tham khao [4(tap1)], ta co:+ Nhiet o soi: tsN = 119,6oC.+ An nhiet ngng tu: rN = 2208 (KJ/kg).
San pham ay trc khi vao noi un co nhiet o lat1 = 99oC (do x1=0,0067 ), nhiet o ra la tW = 100oC.a . Suat lng hi nc can dung :
Lng nhiet can tai cung cap cho ay thap: Q =
265,148 (KW).Suat lng hi nc can dung:
GhN =2208
148,265d =Nr
Q= 0,120 (Kg/s).
b . Xac nh be mat truyen nhiet :Be mat truyen nhiet c xac nh theo phng trnh
truyen nhiet:
Ftb =log. tK
Qd
,(m2) (IV.12).
Vi: + K : he so truyen nhiet.+ tlog : nhiet o trung bnh logarit.
Xac nh tlog :Chon kieu truyen nhiet ngc chieu, nen:
096,20
1006,119
996,119
)1006,119()996,119(log =
=
Ln
t(oK).
Xac nh he so truyen nhiet K:He so truyen nhiet K c tnh theo cong thc:
D
t
N
r
K
11
1
++
=
,(W/m2
.o
K) (IV.13).
Vi: + N : he so cap nhiet cua hi nc(W/m2.oK).
+ D : he so cap nhiet cua san pham ay(W/m2.oK).
+ rt : nhiet tr cua thanh ong va lp cau.* Xac nh he so cap nhiet cua hi nc:
He so cap nhiet cua hi nc c xac nh theocong thc:
55
217
16211622
162316241625162616271628162916301631163216331634
16351636
1637
163816391640
1641
1642
1643
16441645
1646
16471648
1649
16501651
16521653
1654165516561657
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
N =25,0
1
25,0
1 021,0).6,119(
1000.2208..725,0
).(..725,0
=
wtrwsNN
tA
dtt
rA
= 25,01 )6,119(
.415,73
wt
A
Vi: + tw1 : nhiet o cua vach tiep xuc vi hinc(trong ong).
+ A : he so phu thuoc vao tnh chat vat lync theo nhiet o, c tra tai lieu thamkhao [2].
Nhiet tai pha hi: 75,011 )6,119.(.415,73).( wwsNNN tAttq == (W/m2)
(IV.14).* Nhiet tai qua thanh ong va lp cau:
t
ww
tr
ttq
=
21
, (W/m2).Trong o:
+ tw2 : nhiet o cua vach tiep xuc vi sanpham ay (ngoai ong).
+ 21 rrrt
t
t ++=
Be day thanh ong: t = 2 (mm).He so dan nhiet cua thep khong g: t =
17,5 (W/moK).Nhiet tr trung bnh cua lp ban trong ong
vi nc sach: r1 = 1/5000 (m2.oK/W).Nhiet tr lp cau pha san pham ay: r2
=1/500(m2.oK/W).Suy ra: rt = 1/1944,444 (m2.oK/W).
Vay: qt = 1944,444.(tw1-tw2) (IV.15).* Xac nh he so cap nhiet cua san pham ay:
He so cap nhiet cua san pham ay c xacnh theo cong thc (che o soi sui bot va xem
san pham ay nh la nc): D =
3600
8,4186.39.p0,5.(tw2 100)2,33
Vi: + p: ap suat e at nhiet o soi cuasan pham ay, khi o
p = 1 at = 105 (N/m2).Suy ra: D = 14343,143(tw2 100)2,33
Nhiet tai pha san pham ay:33,3
22 )100(143,14343)100.( == wwDD ttq (W/m2)(IV.16).
Chon: tw1 = 116,655o
C :
56
221
1658
1659
166016611662166316641665
1666
16671668
1669
167016711672
1673
1674
16751676
1677167816791680
168116821683168416851686
1687
168816891690
16911692
1693
1694
1695
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Khi o, nhiet o trung bnh2
655,1166,119 +=
118,128oC ta tra cA = 187,1574
T (IV.14): qN =73,415.187,1574.(119,6-116,655)0,75
= 30889,133(W/m2).Xem nhiet tai mat mat la khong ang ke: qt =
qN =30889,133 (W/m2).
T (IV.15), ta co: tw2 = tw1-444,1944
tq =100,769oC
T (IV.16): qD =14343,143.(100,769-100)3,33=31708,196(W/m2).
Kiem tra sai so:
=133,30889
196,31708133,30889 =
D
DN
q
qq=2,65% < 5% :
thoa.Vay: tw1 = 116,655oC va tw2 = 100,769oC.
Khi o: 670,10488)655,1166,119(
1574,187.415,7325,0
=
=N (W/m2.oC).
758,24986)100769,100.(143,14343 33,3 ==D (W/m2.oC).
T (IV.13):295,1539
758,24986
1
444,1944
1
670,10488
1
1=
++=K
(W/m2.oC).
T (IV.12), be mat truyen nhiet trung bnh:096,20.295,1539
1000.148,265=tbF = 8,572 (m2).
Chon so ong truyen nhiet: n = 91 (ong).Chieu dai ong truyen nhiet:
L304,1
2
021,0025,0.91.
572,8=
+=
(m).
Chon: L = 1,5(m),(d tr khoang 10%).Vay: noi un gia nhiet san pham ay la thiet b
truyen nhiet vo - ong vi so ong n = 91, chieu daiong truyen nhiet L = 1,5(m).Ong c bo tr theo hnh luc giac eu. Nen ta co
so ong tren ng cheo hnh luc giac: b = 9(ong).Chon bc ngang gia hai ong: t = 1,4.dng = 1,4.0,025 =0,035 (m).
ng knh vo thiet b: Dv = t.(b-1)+4.dng = 0,035(9-1)+4.0,025
= 0,380(m).4 . Thiet b trao oi nhiet gia nhap lieu
va san pham ay:
57
225
1696
169716981699
170017011702
1703
170417051706
1707
17081709
1710
1711
1712
1713
17141715
17161717
1718
17191720
172117221723172417251726172717281729
1730
1731
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
Chon thiet b thiet b trao oi nhiet gia nhap lieuva san pham ay la thiet b truyen nhiet ong longong. Ong truyen nhiet c lam bang thep X18H10T,kch thc ong trong: 25x2 ; kch thc ong ngoai: 38x2.
Dong nhap lieu i trong ong 25x2 (ong trong) vi nhieto au: tF = 28oC.
San pham ay i trong ong 38x2 (ong ngoai)vi nhieto au: tW = 100oC, nhiet o cuoi: tW = 60oC.
Cac tnh chat ly hoc cua san pham ay c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet o trung bnh
ttbW =2
' WW tt + =80oC:
+ Nhiet dung rieng: cW = 4,195 (KJ/kg.o).+ Khoi lng rieng: W = 971,8 (Kg/m3).
+ o nht ong lc: W = 0,355.10-3
(N.s/m2
).+ He so dan nhiet: W = 0,675 (W/moK).a . Nhiet o dong nhap lieu sau khi trao oi
nhiet vi san pham ay:Suat lng san pham ay:
GW = W.MW = 42,477.18,032 = 765,939 (Kg/h).Lng nhiet can tai:
Qt =3600
WG .cW.(tW-tW) =3600
939,765.4,195.(100-
60)=35,701(KW).
28oC, ta xem nhiet dung rieng cua san pham nhla hang so, hay nhiet dung rieng cua ru cR = 2,595(KJ/kg.o).
Suy ra: cF = cR . Fx +(1- Fx ).4,18 = 2,595.0,2212+(1-0,2212).4,18
= 3,829 (KJ/kg.o).Nhiet o san pham nh sau khi trao oi nhiet vi
san pham ay:
tF =28
3600
1000
.829,3
701,35'
.+=+ F
FF
t tGc
Q
= 61,566oC.
Cac tnh chat ly hoc cua san pham nh c tra tai lieu tham khao [4 (tap 1)] ng vi nhiet otrung bnh ttbF =
,442
28566,61
2
'"=
+=
+DD
tt
oC:+ Khoi lng rieng: F = 954,37 (Kg/m3).+ o nht ong lc: F = 1,06.10-3 (N.s/m2).
58
229
1732173317341735173617371738173917401741
1742
1743
1744
1745174617471748174917501751
1752
1753
17541755175617571758175917601761
1762
176317641765
1766
1767
1768
1769
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
+ He so dan nhiet: F = 0,5184 (W/moK).b . Xac nh be mat truyen nhiet :
Be mat truyen nhiet c xac nh theo phng trnhtruyen nhiet:
Ftb = log. tKQ
t
,(m2) (IV.17).Vi: + K : he so truyen nhiet.
+ tlog : nhiet o trung bnh logarit. Xac nh tlog :
Chon kieu truyen nhiet ngc chieu, nen:
119,35
2860
566,61100
)2860()566,61100(log =
=
Ln
t(oK).
Xac nh he so truyen nhiet K:
He so truyen nhiet K c tnh theo cong thc:
W
t
F
r
K
11
1
++=
,(W/m2.oK) (IV.18).
Vi: + F : he so cap nhiet cua dong nhap lieu(W/m2.oK).
+ W : he so cap nhiet cua san pham ay(W/m2.oK).
+ rt : nhiet tr cua thanh ong va lp cau.
* Xac nh he so cap nhiet cua dong nhap lieu ong trong:Van toc dong nhap lieu i trong ong:
84,0021,0.
4.
37,954.3600
1000
.
4.
.3600 22===
trF
FF
d
Gv (m/s).
Chuan so Reynolds :
48,1588810.06,1
37,954.021,0.84,0.Re
3===
F
FtrFF
dv
> 104 : che
o chay roi, cong thc xac nh chuan so Nusseltco dang:
25,0
2
43,08,0)
Pr
Pr.(PrRe..021,0
w
FFFlFNu =
Trong o:+ l : he so hieu chnh phu thuoc vao ReF va
ty le chieu dai ong vi ng knhong:ReF=15888,48,chon l =1.
+ PrF : chuan so Prandlt cua dong nhap lieu 44,783oC, nen
PrF = 5184,03829.10.06,1. 3
=FFF c
= 7,829.
59
233
1770177117721773
1774
1775
1776
17771778
1779
1780
1781
1782
17831784
17851786
1787178817891790
1791
1792
1793
17941795
1796
1797
17981799
180018011802
1803
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AMH Qua Trnh va Thiet B GVHD : NGUYEN NH THO
+ Prw2 : chuan so Prandlt cua dong nhap lieu nhiet o trung bnh cua vach.
Suy ra: 25,02Pr
346,195
w
FNu =
He so cap nhiet cua dong nhap