do an tham khao 5

7/30/2019 do an tham khao 5

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GVHD: Thay PHAM VAN BONThiet ke thiet b say thungquay say au xanh nguyen hat

PHAN 1: M AU

Say la mot qua trnh cong nghe c s dung rat nhieutrong thc te san xuat va i song. Trong cong nghiep nh chebien nong hai san, che bien go, san xuat vat lieu xaydng, ky thuat say ong mot vai tro quan trong trong daychuyen san xuat. Trong nong nghiep, say la mot trong nhngcong oan quan trong cua cong nghe sau thu hoach San phamsau qua trnh say co o am thch hp, thuan tien cho viec baoquan, van chuyen, che bien, ong thi nang cao chat lngsan pham. o an mon hoc nay, em xin trnh bay ve quytrnh cong nghe va thiet b say thung quay e say au xanhnguyen hat, nang suat 1 tan/h theo san pham.

I. S LC VE NGUYEN LIEU- au xanh, con goi la luc au, boubour, haricotdore, green

bean. Ten khoa hoc: Phaseolus aureus Roxb., Vigna aurea Roxb.Thuocho au Fabaceae (Papilonaceae). Mo ta cay: cay thao, mocng, t phan nhanh, cao 0,6m , la co 3 la chet, la chet hnhtrai xoan, ba canh, mau luc sam, co long nhap. Hoa mau vanghoac luc, rat day ac, xep thanh chum nach, qua namngang hnh tru, co long roi nhan, co au nhon ngan. Hat 1015,phan cach nhau bi cac vach, mau luc, bong.

- au xanh, cung vi au nanh, au en, au trang, auHa Lan.. eu c xep vao hang ho au. ac iem chung cua

chung la cha nhieu protein (25 50%). Do re cua cay ho auco cac not san, o cac vi khuan cong sinh phat trien, cokha nang lay Nit t khong kh nen khong nhng cung cap uNit cho cay ma con lam cho at ai them mau m bangnguon Nit tha thai ra.

- Ve mat cau tao, ho au thuoc cac hat ho hoa thao.Chung khong co noi nhu, noi nhu cua chung b mat trongqua trnh hnh thanh hat. Cau tao chu yeu cua ho au gom 3phan: vo, t diep (la mam) va phoi (mong).

- Thanh phan hoa hoc cua hat au xanh: hat au xanh co

trung bnh:13,7% nc 2,4% lipid 4,6% xenluloza23% protit 52% glucid

- Moi 100g au xanh cung cap cho c the:329 calo 62,7 mgCa 369,5 mgP4,75% Fe 0,06mg% caroten 0,71mg% vitB10,15mg% vitB2 2,4mg% vitPP 4mg% vitC

- au xanh c trong khap nc ta, lay hat chu yeulam thc pham, thng c che bien ngay thanh thc an.

au xanh, ngoai protid con co nhieu glucid, chu yeu la tinh bot,va t lipid. Thanh phan protein cua no cha ay u cac acid

SVTH: ang Th Hoang Lan Trang 1


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amin khong thay the. Tinh bot au xanh co ty le amyloza tngoi rat cao (45 50%), c dung nhieu e che bien mien, lambanh keo

- Van e bao quan au xanh cung nh cac nguyen lieuho au noi chung la kho, v au la moi trng rat thch hp

cho cac loai sau mot pha hoai. Mat khac, neu ieu kien baoquan khong tot nh nhiet o, o am cao, au se b sng(hoa gia) lam giam chat lng au. Muon bao quan lau daith hat phai co chat lng ban au tot, khong sau mot va coo am an toan. V vay, qua trnh phi, say hat sau khi thu hoachco vai tro rat quan trong trong bao quan, che bien cung nhnang cao chat lng hat.

II. QUY TRNH SAY AU XANH HAT

au c thu hoach t ong ruong, ngi ta chat cay vanhat au ra. Khi mi thu hoach t ruong ve, hat thng co oam cao trung bnh 20 25%. oi vi au xanh thu hoach ca vo thphai phi, say s bo ti o kho nhat nh mi tach, lay hatkhoi vo thuan li. Viec ap va tach hat au ra khoi qua cothe lam bang may hoac bang tay. Sau o tien hanh lam sach,tach nhng tap chat trong hat nh co, rac, manh, canh la, at

soi, a, manh kim loai lan vao hat khi thu hoach, tach hat.Co the tach bang sang, ray: tap chat hu c (co, rac, canh,


au xanh

Thu hoach

Phi (say sbo)

ap, tachhat

Vo

Lam sachTap chat

Phan loai

Say

Lam nguoi

Kiem trac hat

ong goi

Thanhpham


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la) ln hn hat nen lp tren cung, lp gia la hat, lpdi cung la at, cat, rac vun nho hn hat. Sau khi co khoiau sach th tien hanh lay mau o o am bang may o oam e xac nh o am ban au. Tiep theo, ngi ta phan loaiau theo loai 1, 2, 3 theo kch c, co the dung sang vi cac

lp li co ng knh lo khac nhau. Sau khi phan loai, tienhanh say theo tng loai au. Sau thi gian say phai kiem tra laio am, o am thanh pham at 14% th qua trnh say ket thuc.Sau khi say, au c lam nguoi t nhien hoac co quat thoie giam nong, tranh dung khong kh co o am cao e thonggio se lam tang o am hat. Tiep theo, khoi au c kiem tralai c hat e loai bo nhng hat lep, hong sau khi say. Co thedung sang e phan loai hat. Cuoi cung, au c ong goitheo yeu cau th trng: 50 kg, 25 kg, 10 kg, 5 kg, 1kg. San phamau xanh nguyen hat.

III. PHNG PHAP THC HIEN QUA TRNH SAY- Muon bao quan lng thc hoac che bien san pham co

chat lng cao, cac loai hat can c say kho xuong o ambao quan hoac che bien. e thc hien qua trnh say co thes dung nhieu he thong say nh buong say, ham say, thapsay, thung say Moi he thong co nhng u, khuyet iem vapham vi ng dung khac nhau. Che o say co anh hng ratln en chat lng san pham v say la mot qua trnh trao oinhiet chat phc tap va lam thay oi khong nhng cau trucvat ly ma con ca thanh phan hoa hoc cua nguyen lieu.

- e say au xanh la nong san dang hat, ngi ta thngdung thiet b say thap hoac say thung quay. o an monhoc nay, em chon thiet b say thung quay, la thiet b chuyendung e say vat lieu dang hat, cuc nho va c dung rongrai trong cong nghe sau thu hoach. Trong thiet b say thung quay,vat lieu c say trang thai xao tron va trao oi nhiet oilu vi tac nhan say. Trong qua trnh say, hat c ao tronmanh va tiep xuc tot vi tac nhan say nen toc o saynhanh va hat c say eu. He thong say thung quay co thelam viec lien tuc vi nang suat ln.

- Tac nhan say s dung cho qua trnh say co the lakhong kh nong hoac khoi lo. Qua trnh say au xanh hat dunglam thc an oi hoi am bao tnh ve sinh cho san pham, nen ay em chon tac nhan say la khong kh, c lam nongtrong caloriphe, nhiet cung cap cho khong kh trong caloriphe la tqua trnh ngng tu hi nc bao hoa. Nhiet o tac nhan sayc chon phu thuoc vao ban chat cua hat. Co loai hat say nhiet o cao van gi c tnh chat vat ly, sinh ly va congnghe, nhng co loai khong cho phep say nhiet o cao. oivi au xanh la loai nguyen lieu cha lng am cao th say



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nhiet o thap, vi nhiet o khong kh say t 40 55 oC 1. Doo, em chon nhiet o tac nhan say a vao thung say la55oC, che o say cung chieu.

- Qua trnh hoat ong cua he thong:au xanh co o am ban au 20% c chuyen vao thung

say bang bang tai va di chuyen trong thung say cung chieuvi tac nhan, vi o cha ay 18%. Thung say hnh tru tron,at nghieng 1,7o so vi mat phang ngang, tren he thong conlan va con lan chan. Toc o quay thung la 1 vong/phut.He thong truyen ong cho thung quay gom banh rang vonglap tren vo thung, ong c truyen ong va hop giam toc.Ben trong thung co gan cac canh nang doc theo ng sinhcua thung e nang va ao vat lieu, lam tang dien tch tiepxuc gia vat lieu va tac nhan say, tang be mat trao oinhiet giup ay nhanh qua trnh say. au nhap lieu cua

thung, canh nang c bo tr xoan ong vai tro nh c cauhng dong cho vat lieu say i vao thung. Khi thung quay, hatc mang len cao ti goc ri roi o xuong, trong luc o tacnhan say nong 55oC, c quat hut van chuyen i vi van toc2,6 m/s, thoi qua, trao oi nhiet am va lam kho hat. Nh onghieng cua thung ma hat se c van chuyen dan ra phathao lieu. Thi gian lu cua vat lieu trong thung say la 0,8 gi.Ket thuc qua trnh say, au xanh co o am 14%, c dan rangoai bang bang tai, a vao he thong ong bao. Khong khnong c a qua xyclon e lang bui roi thai ra ngoai.

1Theo oan Du, Bui Duy Han, Vo Van Man, Lo say thu cong, NXB KHKT, HaNoi, 1971.



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Hnh 1 : Mot so he thong say thung quay

PHAN 2: TNH TOAN THIET B SAY

Vat lieu say la au xanh nguyen hat co cac thong so cban nh sau:

o am ban au cua vat lieu say (theo nguyen lieuam):

1 = 20% = 0,2

o am cuoi cua vat lieu say (theo nguyen lieu am):2 = 14% = 0,14

o xop cua khoi hat vat lieu (lay theo hat aunanh): [11]

Khoi lng rieng cua hat vat lieu: [5]

r = 1000 1400 kg/m3

Khoi lng rieng the tch cua vat lieu:

r

v

=1 78560)1( == rv kg/m3

Chon v= 650 kg/m3

Nhiet dung rieng cua vat lieu kho: [6]

Cvk = 1,2 1,7 kJ/kg.oKChon Cvk = 1,5 kJ/kg.oK



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ng knh trung bnh cua hat vat lieu: d = 5 mm =0,005m

Nang suat (theo san pham): G2 = 1000 kg/h.

I. TNH CAN BANG VAT CHAT1. Tnh cac thong so cua tac nhan say:1.1. Cac cong thc s dung: [1], [10]

Dung tac nhan say la khong kh.- Phan ap suat bao hoa cua hi nc trong khong kh am

theo nhiet o:

+=

Ctp

ob 5,235

42,402612exp ,bar (CT 2.31, [10])

- o cha am:

b

b

pB

px

.

.621,0

= ,kg/kgkk (CT 2.18, [10])

vi: . B: ap suat kh tri, B = 1at = 0,981 bar- Enthapy cua khong kh am:

).842,12500(.004,1).(. txttCrxtCI papk ++=++= ,kJ/kgkk

(CT 2.25, [10])

vi: . Cpk : nhiet dung rieng cua khong kh kho, Cpk= 1,004 kJ/kgoK

. Cpa : nhiet dung rieng cua hi nc, Cpa = 1,842kJ/kgoK

. r : an nhiet hoa hi cua nc, r =2500 kJ/kg- The tch rieng cua khong kh am:

bb pB

T

pBM

RTv

..288

).( =

= ,m3/kgkk (CT VII.8, [1])

vi: . R : hang so kh, R =8314 J/kmol.o. M : khoi lng khong kh, M = 29 kg/kmol. B, pb : ap suat kh tri va phan ap suat bao

hoa cua hi nc trong khong kh, N/m2

- Lu lng khong kh am:

V = v.L ,m3/kg

vi: . L : lu lng khong kh kho, kg/h. v : the tch rieng cua khong kh am, m3/h

- Khoi lng rieng cua khong kh am:



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=

B

p

T

T book

..378,01

,kg/m3 (CT 1.11, [8])

trong o: . o = 1,293 kg/m3: khoi lng rieng khong kh kho ieu kien chuan

. To = 273oK : nhiet o khong kh ieu kienchuan.

1.2. Tnh cac thong so cua tac nhan say:

- Trang thai khong kh ngoai tri: c bieu dien bangtrang thai A, xac nh bang cap thong so (to, o).

Do vat lieu say la au xanh co the c trong va thuhoach nhieu vu trong mot nam, tuy nhien tnh theo mua ma, tnang th thiet b se lam viec tot quanh nam. V vay, ta chontrang thai A theo gia tr trung bnh vao thang 9 Thanh pho Ho

Ch Minh: [1]A: to = 27 oC

o = 84%

035,0275,235

42,402612exp

5,23542,4026

12exp =

+=

+

=o

bt

po

(bar)

019,00355,0.84,0981,0

0355,0.84,0621,0

.

.621,0 =

=

=

obo

oboo

pB

px

(kg/kgkk)

721,76)27.842,12500.(0194,027.004,1

).842,12500(.004,1

=++=

++= oooo txtI

908,010.0355,0.84,010.981,0

)27327(288.

.28855

=

+=

=

obo

oo

pB

Tv

(m3/kgkk)

- Khong kh c quat a vao caloriphe va c ot nongang am (x1 = xo) en trang thai B (x1, t1). Trang thai B cung latrang thai cua tac nhan say vao thung say.

Nhiet o t1 tai iem B la nhiet o cao nhat cua tac nhansay, do tnh chat cua vat lieu say va che o cong nghe quynh. Nhiet o cua tac nhan say B c chon phai thap hn

nhiet o ho hoa cua tinh bot au xanh. Do au xanh la loai hatgiau tinh bot, ban au khi o am cua vat lieu say con cao,neu vat lieu tiep xuc vi tac nhan say nhiet o cao th lpbe mat cua hat tinh bot b ho hoa va tao thanh mot lp keomong bt kn be mat thoat am t trong long vat lieu ra ngoai.

Quy tac say oi vi loai nguyen lieu cha lng am caoth say nhiet o thap, v du nh say mot so loai au hatcha nhieu am th nhiet o khong kh say t 40 55oC.

Do o, chon iem B: t1 = 55oCx1 = xo = 0,0194 (kg/kgkk)


(kJ/kgkk)


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191,0)0194,0621,0.(1556,0

981,0.0194,0

)621,0(

.

1

11

1

=+

=

+=

xp

Bx

b


155,0555,235

42,402612exp

5,23542,4026

12exp1

1=

+=

+

=t

pb (bar)

11

111 .

.621,0

b

b

pB

px

=

836,105)55.842,12500.(0194,055.004,1

).842,12500(.004,1 1111=++=

++= txtI

993,010.1556,0.1915,010.981,0

)27355(288.

.288551

11

1

=

+=

=

bpB

Tv

(m3/kgkk)

- Khong kh trang thai B c ay vao thiet b say ethc hien qua trnh say ly thuyet (I1 = I2). Trang thai khong kh

au ra cua thiet b say la C (t2, 2).Nhiet o cua tac nhan say ra khoi thiet b say t2 tuy

chon sao cho ton that nhiet do tac nhan say mang i la benhat, nhng phai tranh hien tng ong sng, ngha la tranhtrang thai C nam tren ng bao hoa. ong thi, o chaam cua tac nhan say tai C phai nho hn o am can bangcua vat lieu say tai iem o e vat lieu say khong hut amtr lai.

Vi I2 = I1 = 105,8369 kJ/kgkk

= 100%Chon t2 = 35oC.

055,0355,235

42,402612exp

5,23542,4026

12exp2

2=

+=

+

=t

pb (bar)

).842,12500(.004,1 2222 txtI ++=

029,035.842,12500

35.004,18369,105.842,12500

.004,1

2

222 =+

=

+

=t

tIx (kg/kgkk)

784,0

)0290,0621,0.(0558,0

981,0.0290,0

)621,0(

.

2

22

2

=

+

=

+

=

xp

Bx

b

946,010.0558,0.7844,010.981,0

)27335(288.

.288552

22

2

=

+=

=

bpB

Tv

(m3/kgkk)

- So sanh x2 vi o am can bang cua vat lieu say:

Bang 1 : Ham am can bang cb cua vat lieu say (vi vatlieu say la au nanh): [5], [9]

(kg am/kg chat kho)

toCo am khong kh, %

20 30 40 50 60 70 80 90 10030 - 0,0563 0,06 0,068 0,0846 0,103 0,142 0,199 0,304


(kJ/kgkk)

ts 31oC


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20 0,054 0,065 0,071 0,08 0,095 0,116 0,153 0,209 -

Ta thay, tai iem C (t2 = 35oC, 2 = 78,4%), ham am canbang cua vat lieu say cb 0,128 (kg/kg) o cha am cuakhong kh x2 < cb, vat lieu say khong hut am tr lai.

- Tom lai, trang thai tac nhan say trong qua trnh say lythuyet:

Bang 2 : Trang thai tac nhan say trong qua trnh say lythuyet:

ai lng Trang thaikhong kh ban

au (A)

Trang thai khongkh vao thiet b

say (B)

Trang thai khongkh ra khoi thiet b

say (C)t (oC) 27 55 35 (n v) 0,84 0,1915 0,7844x

(kg/kgkk)

0,0194 0,0194 0,0290

I (kJ/kgkk) 76,7213 105,8369 105,8369pb (bar) 0,0355 0,1556 0,0558v(m3/kgkk)

0,9083 0,9931 0,9465

2. Tnh can bang vat chat: [8]

- Nang suat thiet b say theo nhap lieu:

1072,0114,01

.10001

1.

1

221 =

=

=

GG (kg/h)

- Lng am can tach:W = G1 G2 = 1075 1000 = 75 (kg/h)

- Lng tac nhan kho can thiet:

74,78370194,0029,0

75

12=

=

=

xx

WL (kg/h)

- Lng tac nhan tieu hao rieng:

50,1040194,0029,0

11

12=

=

==

xxW

Ll (kgkk/kg am)

II. TNH CAN BANG NANG LNG [10]Qua trnh say khong co bo sung nhiet lng, QBS = 0Thiet b say thung quay khong co thiet b chuyen tai, QCT

= 0- Nhiet lng a vao thiet b say gom:

Nhiet lng do tac nhan say nhan c trong caloriphe:L(I1 Io)

Nhiet lng do vat lieu say mang vao: [(G1 - W)Cv1 +

WCa].tv1- Nhiet lng a ra khoi thiet b say gom:



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Nhiet lng ton that do tac nhan say mang i: L(I2 Io)

Nhiet lng ton that qua c cau bao che: QBC Nhiet lng do vat lieu say mang ra: G2.Cv2.tV2

Vi:

o tv1 : nhiet o ban au cua vat lieu say, thnglay bang nhiet o moi trng: tv1 = to = 27oC

o tv2 : nhiet o cuoi cua vat lieu say sau khi ra khoithiet b say:

tv2 = t2 (5 10oC) = 35 5 = 30oC

o Cv1 = Cv2 = Cv : nhiet dung rieng cua vat lieu sayvao va ra khoi thiet b say la nh nhau. ay, Cvla nhiet dung rieng cua vat lieu say vi o am2:

Cv = Cvk(1-2) + Ca.2 ,kJ/kgo

K Ca: nhiet dung rieng cua am.Vi am la nc th: Ca = Cn = 4,18 kJ/kgoK

Cv = Cvk(1-2) + Ca.2= 1,5.(1 - 0,14) + 4,18.0,14= 1,8752 (kJ/kgoK)

- Can bang nhiet lng vao va ra he thong say:L(I2 I1) + [(G1 - W)Cv1 + WCa].tv1 = L(I2 Io) + QBC + G2.Cv2.tV2

at: Qv = G2Cv(tv2 tv1) : ton that nhiet do vat lieu say mang

i.Mat khac: G2 = G1 W

Cv1 = Cv2 = Cv- Nhiet lng tieu hao cho qua trnh say thc:

Q = L(I1 Io) = L(I2 Io) + QBC + Qv - WCatv1- Nhiet lng tieu hao rieng (cho 1kg am can boc hi):

q = l(I1 Io) = l(I2 Io) + qBC + qv Catv1trong o:

W

Q

q

BC

BC = ; W

ttCG

W

Q

q

vvvv

v

)( 122

== Ton that nhiet do vat lieu say:

Qv = G2Cv(tv2 tv1) = 1000.1,8752.(30 27) = 5625,6 (kJ/h)

00,7575

6,5625===

W

Qq vv (kJ/kg am)

Nhiet do am trong vat lieu a vao:WCatv1 = 75.4,18.27 = 8464,5 (kJ/h)Ca.tv1 = 4,18.27 = 112,86 (kJ/kg am)

Ton that nhiet qua c cau bao che:QBC = (0,03 0,05).Qhi [14]



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Qhi : nhiet hu ch, la nhiet can thiet e lam bay hiam trong vat lieu:Qhi = W.[rtv1 + Ca(t2 tv1)] [8]vi:

o rtv1 : an nhiet hoa hi cua nc trong vat lieu say nhiet o vao, rtv1 = 2500 kJ/kg

o Ca : nhiet dung rieng cua am.Vi am la hi nc th: Ca = Cpa = 1,842 kJ/kgoK

Qhi = 75.[2500 + 1,842.(35 27)] = 188605,2(kJ/h) QBC = 0,03.Qhi

= 0,03.188605,2 = 5658,156 (kJ/h)

442,75

75

156,5658===

W

Qq BCBC (kJ/kg am)

- at: C atv1 qBC qv : nhiet lng rieng can bo sung choqua trnh say thc, la ai lng ac trng cho s sai khac giaqua trnh say thc te va say ly thuyet.

Vi qua trnh say ly thuyet: = 0Nhiet lng tieu hao cho qua trnh say ly thuyet:Q = L(I2 Io)= 7837,742.(105,8369 76,7213) = 228200,399 (kJ/h)q = l(I2 Io)

= 104,503.(105,8369 76,7213) = 3042,672 (kJ/kg am) Vi qua trnh say thc te: 0 = Catv1 qBC qv

= 112,86 75,4421 75,008 = -37,5901 (kJ/kg am)< 0 Catv1 < qBC + qv

I2 < I1 trang thai tac nhan say sau qua trnh say

thc nam di ng I1 (ng say thc te nam di ngsay ly thuyet)

T o ta xac nh lai cac tnh chat cua tac nhan say khira khoi thung say:

lII

+=2

Tuy nhien v l cha biet nen ta xac nh o cha am x2trc thong qua t2 a biet:



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027,0)]5901,37()35.842,12500[(

)]5901,37()55.842,12500.[(0194,0)3555(004,1

])[(

])[()(

)(

)()(

2

121

2

212

=+

++=

+

++=

+=

tCr

tCrxttC

i

ixttCx

pa

paopk

opk

536,105)35.842,12500(0274,035.004,1

).842,12500(.004,1 2222=++=

++= txtI

055,0355,235

42,402612exp

5,23542,4026

12exp2

2=

+=

+

=t

pb (bar)

743,0)0274,0621,0.(0558,0

981,0.0290,0)621,0(

.

2

22

2

=

+

=

+

=xp

Bx

b

944,010.0558,0.7436,010.981,0

)27335(288.

.288552

22

2

=

+=

=

bpB

Tv

(m3/kgkk)

- Tom lai, trang thai cua tac nhan say trong qua trnh saythc te:

Bang 3 : Trang thai cua tac nhan say trong qua trnh saythc:

ai lng Trang thaikhong kh ban

au (A)

Trang thai khongkh vao thiet b

say (B)

Trang thai khongkh ra khoi thiet b

say (C)t (oC) 27 55 35 (n v) 0,84 0,1915 0,7436x(kg/kgkk)

0,0194 0,0194 0,0274

I (kJ/kgkk) 76,7213 105,8369 105,5365pb (bar) 0,0355 0,1556 0,0558v(m3/kgkk)

0,9083 0,9931 0,9442


(kg/kgkk

(kJ/kgkk)


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Hnh 2: o th I d khong kh am

- Lng tac nhan kho can thiet:



14/61


853,93830194,00274,0

75

12=

=

=

xx

WL (kg/h)

Lng tac nhan tieu hao rieng:

118,1250194,00274,0

11

12=

=

==

xxW

Ll

(kg/kg am)- Lng nhiet can cung cap cho qua trnh say thc:

Q = L(I2 Io) + QBC + Qv - WCatv1= 9383,8531.(105,5365-76,7214) + 5658,156 + 5625,6

8464,5= 273216,3084 (kJ/h)

Lng nhiet cung cap rieng:

884,3642==W

Qq (kJ/kg am)

- Hieu suat say:

69,03084,273216

2,188605===

Q

Qhi

III. TNH THI GIAN SAY[8]1. Tnh cng o say:

- Nhiet o trung bnh cua tac nhan say trong thiet b say:

452

35552

21 =+=+= tttk (oC)

- o am trung bnh cua tac nhan say trong thiet b say:

467,02

7436,01915,02

21 =+

=+

=

k

- Phan ap suat bao hoa cua hi nc trong tac nhan say:

094,0455,235

42,402612exp

5,23542,4026

12exp =

+=

+=

tpb (bar)

- Khoi lng rieng cua tac nhan:

091,1981,0

0949,0.4675,0.378,01

)27345(

273.293,1

..378,01

=

+=

=

B

p

T

T book

- Chon cac thong so e tnh cng o say:

Bang 4 : Cac thong so chon e tnh cng o say:

STT ai lng Ky

hieu

n

v

Khoang gii

han

Tai

lieutham

Cho

n


(kg/m3)


15/61


16/61


Whmax c xac nh theo cong thc:

ln11

maxB

WW hcb+=

ln

11

maxhcb WWB

=

vi: . Wcb : o am can bang cua vat lieu, %. B : he so phu thuoc vao nhiet o.

V < 1 ln < 0

e B > 0 thmax

11

hcb WW Whmax (1)Ma qua trnh say ay co o am cuoi (W2 = 14%)

> o am can bang (Wcb = 12,8%): W2 > Wcb (2)

(1), (2) W2 Whmax

Vay ta lay 1max

2 =hW

Wtrong cong thc tnh A.

( ) 712,101.277,1

.18,0.7407,0.1.005,0

6,2.091,1.03,3 5,0 ==

tg

tgA (kg/m3h)

1. Tnh thi gian say:

79,0)]1420(200.[7123,10

)1420.(18,0.650.2)](200[

).(.2

21

21 =+

=

+

=WWA

WWv (h)

= 47,37 (ph)

IV. TNH THIET B CHNH [8]1. Tnh kch thc thung quay:

- The tch thung say:

001,77123,10

75===

A

WVT (m3)

- Chon ng knh thung, theo tieu chuan: DT = 1,2m

- Chieu dai thung:190,6

2,1.

0013,7.4422

=== T

TT

D

VL (m)

Chon LT = 6,5m 42,52,11905,6

==T

T

D

L

thoa ieu kien 84=T

T

D

L

Khi o, the tch cua thung say:



17/61


351,75,6.4

2,1..

4

22

===

L

DV TT (m

3)

1. Thi gian lu:

Thi gian ma vat lieu lu tru trong thung (thi gian vatlieu i het chieu dai thung):

80,01075

650.18,0.3513,7.

11 ===

G

V vT (h) = 48,01 (ph)

thoa ieu kien 1

2. Kiem tra toc o quay cua thung:

tgD

Lkmn

T

T

..

..

1

1= ,vg/ph

trong o:. k1 : he so lu y en ac tnh chuyen ong cuavat lieu.

Trng hp say xuoi chieu: k1 = 0,2 0,7 Chon k1 = 0,5

. m : he so lu y en dang canh trong thung.oi vi canh nang, m = 0,5

950,07,1.2,1.01,48

5,6.5,0.5,0..

..

1

1 ===tgtgD

Lkmn

T

T

(vg/ph)

Sai so so vi gia tr chon:

%96,4%100.19504,01%100. ===

nnn

chon n = 1 vg/ph la hp ly.

3. Kiem tra van toc tac nhan say:

Bang 5 : Lu lng va khoi lng rieng khong kh say taicac iem cua qua trnh say thc:

ailng

Ky

hieu n v

Trang thaikhong kh

ban au A(trang thai1)

Trang thaikhong kh

vao thiet bsay B

(trang thai2)

Trang thaikhong kh ra

khoi thiet bsay - C (trangthai 3)

Ghichu

Nhieto

t (oC) 27 55 35Bang 3

oam

(nv)

0,84 0,1915 0,7436Bang 3

Lulng

V(m3/h)

8523,6411 9319,1810 8860,1435

V (m3/s) 2,3677 2,5887 2,4612

Khoilng

(kg/m3)

1,1631 1,0638 1,1277



18/61


rieng

- Lng tac nhan say trung bnh trong thung say:

662,90892

144,8860181,93192

21 =+

=+

=VV

V (m3/h)

= 2,5249 (m3/s)- Tiet dien chay cua tac nhan:

927,042,1.

)18,01(4

)1().1(22

====

TTD

FF (m2)

- Van toc tac nhan say:

722,29274,05249,2

===F

Vvk (m/s)

- Sai so so vi van toc chon:

%50,4%100.7226,2 6,27226,2%100. === kkk

vvv

chon v k = 2,6 m/s la hp ly.4. Tnh be day cach nhiet cua thung:

May say co the co hay khong co boc lp cach nhiet.e tranh nhiet trong may say mat mat nhieu va e ambao nhiet do ben ngoai may say co the cho phep cong nhanlam viec ben canh c th thng boc lp cach nhiet cho maysay.

5.1. He so cap nhiet t dong tac nhansay en thanh trong cua thung 1:

Bang 6 : Cac thong so cua tac nhan say trong thungsay:

STT Thong soK

hieun v

Nguon Cong thc

Gia tr

1 Van toc vk m/s (III.1) 2,62 Nhiet o trung

bnhtk oC (III.1) 45

3 He so dannhiet k W/m.

o

K Bang 30, [3] 0,027554 o nht k Ns/m

2 Bang I.114,[1]

1,9314.10-5

5 Khoi lngrieng

k kg/m3 (III.1) 1,0910

6 o nht ong k m2/sk

kk

= 1,7702.10-5

- Che o chay cua tac nhan say trong thiet b:Chuan so Reynolds:



19/61


55

10.7625,110.7702,1

2,1.6,2Re ===

k

TkDv

Re > 104 dong tac nhan chay roi trong thung say. Quatrnh truyen nhiet trong thung xem nh la qua trnh truyen nhiet

trong ong co dong chay xoay roi, la qua trnh truyen nhiet dos tron lan cua cac lp lu chat trong va ngoai xa truc cuadong chay. Co the bo qua s truyen nhiet do oi lu t nhien.[2]

Vay, qua trnh truyen nhiet gia tac nhan say va thanhthiet b la truyen nhiet do oi lu cng bc, dong chay trong

ong co 50==h

p

Do o be day toi thieu cua than thung:

)(10.5,495,0.140.2

1,0.2,1].[2

. 4 mpD

Sh

T ===

(CT 5.3, [15])

- He so bo sung kch thc:C = Ca + Cb + Cc + Co (CT 1.10, [15])


(J/kg am)


24/61


Bang 10 : Cac he so bo sung kch thc cho be day thung:

STT

He sobo sung

kch thc

Khie

u

Giatr

(mm)Ghi chu

1He so bosung do anmon hoahoc

Ca 0oi vi vat lieu ben trong moitrng co o an mon hoa hockhong ln hn 0,05 mm/nam.

2He so bosung do baomon c hoc

Cb 1

Do nguyen lieu la cac hat ranchuyen ong, va ap trong thietb. Gia tr Cb chon theo thcnghiem.

3

He so bosung do sailech khi

che tao

Cc 0,8

Phu thuoc vao chieu day cuatam thep lam thung. Vi thungbang thep CT3, day 8mm th C3 =

0,8 mm (Bang XIII.9, [1])

4He so quytron kchthc

Co 5,75 Chon.

C = Ca + Cb + Cc + Co = 0 + 1 + 0,8 + 5,75 = 7,55 (mm)

- Be day thc cua than thung:S = S + C = (0,45 + 7,55).10-3 = 8.10-3 (m)

gia thiet be day thung 8 mm la chap nhan c.- Kiem tra:

006,01200

08 ==T

a

D

CS

thoa ieu kien 1,0 N can thiet e quay thung.

1. Chon ty so truyen ong: [4]

- Ty so truyen chung cua toan bo he thong:69

1698

===thung

cc

n

ni

Do ty so truyen qua ln nen phai s dung he thongtruyen ong giam toc cho thung. S dung bo phan giam toc 2cap kieu truc vt banh rang. He thong truyen ong nh sau:truc ong c noi thang vi truc vt, truc vt nay truyen ong quabanh vt (giam cap i01), t banh vt qua banh rang nho cua hopgiam toc, roi qua banh rang ln (giam cap i12), sau o ra khoihop giam toc, truyen qua tang dan ong va en thung qua

banh rang ln gan vao thung (giam cap i23).

- Chon ty so truyen: . i23 = 5. i12 = 4

. 08,296.4

698. 2312

01 ===ii

ii c

- Van toc quay:nj-1 = ij-1,j . nj (vg/ph)

- Cong suat:Nj = Nj-1 . j-1,j (kW)

vi: . Hieu suat h cua bo truyen banh rang tru h: hbr =0,93 0,95


Hnh 4: S o he thong truyen ong

cho thung


27/61


Chon hbr = 0,93. (Bang 2.3, [4]). Hieu suat cua bo

truyen banh rang tru c che kn (trong hop giamtoc): hbr = 0,96 0,98

Chon hbr = 0,96. (Bang 2.3, [4]). Hieu suat cua bo truyen truc vt:

82,096,0.93,0

74,0

. '===

brbr

ctrv

Bang 11 : Bang s o truyen ong

Truc

Thong so ong c Truc I Truc II Truc III

Ty so truyen i 29,083 4 6

Van toc quay n(vg/ph) 698 24 5 1

Cong suat N(kW)

0,698 0,6272 0,602 0,56

2. Tnh bo truyen banh rang [13]

Bo truyen banh rang truyen chuyen ong t tang danong en banh rang ln gan vao thung. ay la c chetruyen ong gia hai truc song song nen ta s dung bo truyenong banh rang tru (rang thang), truyen ong h, banh rangan khp ngoai.

Chon vat lieu lam banh rang:

Banh rang ln: thep 45 thng hoa, co o ran HB180.

Banh rang nho:- oi vi 2 banh rang an khp nhau, bang rang nho lam

viec nhieu, chan rang be nen mon nhieu va chong b gayhn banh rang ln, do vay can c che tao bang vat lieu tothn. Neu s dung 2 banh rang cung vat lieu th phai co phngphap nhiet luyen e banh rang nho co o ran mat rang ln

hn.- Banh rang chu tai trong trung bnh, s dung thep 45

thng hoa co cac thong so c tnh:. o ran HBbr nho = (1,1 1,4)HBbr ln = 1,1.180 = 198. Gii han ben: B = 600 N/mm2

. Gii han chay: C = 340 N/mm2

- ng suat uon cho phep:

[ ]

Knuo .

.5,1 1=

vi: . Gii han moi: -1 = 0,25.(sb + sch) + 50 = 285 (N/mm2)



28/61


. He so an toan: n = 1,5 2,2 chon n = 1,5. He so tap trung ng suat chan

rang: K = 1,2 1,8 (tr so ln dung cho banh rangthep thng hoa va toi) K = 1,8

[ ] )/(35,1588,1.5,1 285.5,1..5,121 mmN

Knuo ===

Tnh moun s bo:

3 36

...][

...10.19

nZy

KNm

mu

= ,mm

vi:

N3 : cong suat truyen cua bo truyen.oi vi bo truyen banh rang tru h co he so

truyen br = 0,93 0,95 chon br = 0,93.

)(6021,093,056,0

3 kWN

Nbr

thung ===

: he so o mon rang

Vi o mon 20% = 1,5

m : he so chieu dai rang, m = 10 12 chon m =12.

Z : so rang.

o Vi banh rang nho (chu ong) quay bang ong c:

Z1 = 17 30 Chon Z1 = 28 rang

o Vi banh rang ln:Z2 = i.Z1 = 5.28 = 140 rang

y : he so dang rang, phu thuoc Z

o Banh rang nho: y = 0,411

o Banh rang ln: y = 0,488

K : he so tai trong, chon s bo K = 1,5 (banh rang at

au truc)Tnh moun theo banh rang co tch y.[]u nho, con neu

banh rang cung vat lieu th tch y.[]u lay cua banh rang nho:

)(224,95,1.28.12.33,158.411,0

5,1.5,1.6021,0.10.19

...][

...10.19

3

6

33

6

mm

nZy

KNm

mu

==

=

Chon moun theo tieu chuan (theo TCVN 1064-71) : m = 10

mm. Kiem nghiem sc ben uon rang:



29/61


[ ]uunZbmy

KN

=

....

...10.192

6

vi:

b : chieu dai rang, mm.

b = m . m =12.10 = 120 (mm) K = Kt.K : he so tai trong

o Kt : he so tai trong tap trung.

Vi o ran mat rang HB < 350 Chon Kt = 1.

o K : he so tai trong ong, phu thuoc vab toc tieptuyen va cap chnh xac cua banh rang.

. Goi A: khoang cach gia 2 tam banh rangm = (0,01 0,02).A

chon m = 0,012A 33,833

012,0

10

012,0===

mA (mm)

lam tron A = 835mm. So rang banh nho:

78,27)16(10

835.2)1(

21 =+

=+

=im

AZ

Z1 = 28 rang

chon Z1 = 28 rangluc au la hp ly.. Xem van toc quay thung bang van toc

quay cua banh rang ln va bang 1vg/ph.

Van toc quay cua banh rang nho: nII = i. nI = 6.1 = 6 (vg/ph). Van toc vong:

)/(0729,0)15.(1000.60

5.8352)1(1000.60

2 1 smi

Anv =

+=

+=

v < 2 m/s chon cap chnh xac cua banh rang = 9

K = 1,2

He so tai trong:K = Kt . K = 1.1,2 =1,2

o ben uon:

)/(852,246.28.120.10.411,0

5,1.2,1.6021,0.10.19

....

...10.19

22

6

2

6

mmN

nZbmy

KNu

==

=

u < [ ] u he an toan ve uon.

Tnh kch thc chu yeu cua cap banh rang:T C B B



30/61


M10

T6

S 2 1

D 2 1

D 3 1

D 2 1



31/61


C h12,5

C h10

C h22,5

K770

VI. CHON KCH THC CANH AO TRONG THUNG

- S dung canh nang co cac thong so ac trng nh sau:(Bang 6.1, [8]):

He so cha ay: = 18%

Goc gap cua canh: = 140 o


Hnh 5: Hnh dang mot so canh aotrong thung


32/61


57,0=TD

h; 122,02 =

T

c

D

F

vi: . h: chieu cao ri trung bnh cua hat vat lieu. DT : ng knh thung

. Fc : be mat cha vat lieu cua canh. Fc = 0,122.DT2= 0,122.1,22 = 0,1757 (m2)

- Chon: . Chieu rong canh: b =155mm. Chieu cao canh: d = 80 mm

. Chieu dai canh: )(750,018,0155,0

1757,0m

db

Fl c =

+=

+=

. Chieu day canh: = 5mm

. So canh tren mot mat cat : 8 canh.

Vi chieu dai thung say LT = 6,5m ta lap 8 oancanh doc theo chieu dai thung, au nhap lieucua thung lap canh xoan e dan vat lieu vaothung, vi chieu dai 0,5m.

- Ty le cha ay vat lieu trong thung:

1F

Fcd=

F1 : tiet dien ngang cua thung

)(1304,142,1,

42

22

1 mD

F T ===

Fc : tiet dien cha ayFc = .F t = 0,18.1,1304 =0,2034 (m2)Do:


Ft

R

h

Fc

Hnh 6: Dien tch phan cha vat lieutrong thung


33/61


o

c

RRF

55

56,06,0

2034,022sin

180.

22sin.

180

2

22

=

==

=

Chieu cao cha ay vat lieu trong thung:h = R Rcos =0,255 (m).

VII. TNH VANH AI VA CON LAN 1. Tnh tai trong thung say:

Vanh ai:

- Chon s bo be rong vanh ai: B = 100mm- Be day vanh ai: oi vi thung tai trong nang chon

)(46,386,2

mmB

h ==

Chon h = 40mm- Vat lieu lam vanh ai: chon thep CT3, = 7850 kg/m 3

- Gan e lap vanh ai vao than thung: cao 50mm, day40mm

- Khoang cach gia gan va than thung e lap chan e:

60mm- ng knh mat ngoai chan e (ng knh trong cuagan):De = DT + 2.60 = 1200 + 2.60 = 1320 (mm)

- ng knh ngoai vanh ai:Dai = 1200 + 2.(60 + 50 + 40) = 1520 (mm)

- Khoi lng 2 vanh ai:Mai = 2. .(V ai + Vgan)

= 2.7850. .[(1,52+0,1).0,1.0,04 + (1,320+0,04).0,04.0,05]

= 433,32 (kg)

Thung say

Bang 12 : Khoi lng thung say, LT = 6,5m

Thongso

Vatlieu

Khoi lngrieng(kg/m3)

ngknh trong

(m)

ngknh

ngoai (m)

Khoilng(kg)

Thanthung

CT3 7850 1,2 1,216 1549,14

Lpcachnhiet

Bongthuytinh

200 1,216 1,218 4,97



34/61


Lpbaove

CT3 7850 1,218 1,220 195,41

Khoi lng thung : Mthung = 1749,52 (kg)

Banh rang- Banh rang xem tng ng vat co tiet dien hnh vanh

khan:. ng knh ngoai xem nh bang ng knh vong lan, Dng

= 1400mm. Rong B = 120mm, day h = 30mm. Khoi lng rieng 7850 kg/m3

Mbrang = 161 (kg)- Gan:

. Chon chieu rong B = 60mm, day h = 55mm

. ng knh trong cua gan:D1 = Day rang 2.(hgan + hrang) = 1375 2.(30+55) = 1205 (mm)

Mgan = 85,45 (kg)

Mbrang = 246,45 (kg)

Canh ao:- Chon vat lieu bang thep CT3, r = 7850 kg/m3

- Cac kch thc a chon VI.

Mcanh = 441,36 (kg) Khoi lng vat lieu trong thung:

- Nang suat thung theo nhap lieu: G1 = 1075 (kg/h)- Thi gian lu cua vat lieu trong thung: = 0,8h

Khoi lng vat lieu trong thi gian lam viec: Mhat = G1. = 860 (kg)Vay tai trong tong cong cua thung say e len con lan la:

== )(65,3730 kgMM i Q = M.g = 36600 (N)

1. Tnh con lan : [15]


Q

S

TN


35/61


- Phan lc cua moi con lan len ai:

)(21121

30cos2

36600

cos2

NQ

T ===

- L c ep con lan len be:N = Tcos Q/2 = 18300 (N)

- Lc ay con lan theo chieu ngang:S = Tsin = 10560,5 (N)

- Be rong con lan, chon:Bc = B + (3 5)cm = 10 + 5 = 15 (cm)

- ng knh con lan thep:

)(52,369,415).400300(

21121

).400300( cmB

T

dc == Chon dc = 500mm.

- Kiem tra lai ng knh con lan:

0,25D dc 0,33Dvi: D : ng knh ngoai cua vanh ai, D = 1520mm.

dc = 500mm thoa ieu kien: 380 dc 501,6 (mm)

VIII. TNH CALORIFER CAP NHIET

- Calorifer la thiet b truyen nhiet dung e gia nhiet giantiep cho khong kh say. Trong ky thuat thng dung hai loaicalorifer la calorifer kh hi va calorifer kh khoi. ay ta choncalorifer kh hi, loai thiet b truyen nhiet kieu ong chum. Trongong la hi nc bao hoa ngng tu va ngoai ong la khong khchuyen ong. He so trao oi nhiet cua nc ngng ln hnnhieu so vi he so trao oi nhiet oi lu gia mat ngoai cuaong vi khong kh, do o, ben ngoai ong pha khong kh clam canh e tang cng truyen nhiet. Vay calorifer s dung laloai ong chum vi ong co canh. Calorifer c bo tr namngang.

Bang 13 : Cac thong so cua cac tac nhan qua calorifer

Tac nhansay

Khong kh

Nhiet o vao t2= to

27oC

Nhiet o ra t2c =t1

55oC

Hi otHi nc bao hoangng tu

Ap suat p 2 atNhiet o ngngtu T

119,6oC

- Chon mot so kch thc cua calorifer e s dung trong tnh

toan:Bang 14 : Mot so kch thc cua calorifer


Hnh 7: Lc tac dung len con lan


36/61

T

t2c

t2

t

FF


Thong soKy

hieunv

Giatr

Ghi chu

Ong

Chieu dai L m 1,5Chon theo tieuchuan, [2]

ng knh

ngoai d2 m 0,016

Chon theo tieu

chuan: ong 16 x 1,6[2]Be day ong m 0,0016

ng knhtrong

d1 m 0,0128 d1 = d2 2

Bc ongngang donglu chat

s1 m 0,05

Chon theo tieu chuanoi vi chum ongco canh, ([2], trang75)

Bc ongdoc dong lu

chat ngoaiong

s2 m 0,0433

Trng hp xep ongso le ( nh tam

giac eu), ([2], trang75):s2 = 0,866.s1

Canh

Chieu daicanh

h m 0,001

ChonKhoang cachgia 2 canhlien tiep

tc m 0,005

Be day canh c m 0,0005ng knhcanh

dc m 0,018 dc = d2 + 2h

He so dan nhietcua vat lieu lamong va canh

W/mK 57 Thep CT20

1. Tnh hieu so nhiet o trung bnh:

- Hieu so nhiet o cua 2 dong lu chat au vao va racua calorifer:t = T t2 = 119,6 27 = 92,6 (oC)tc = T t2c = 119,6 55 = 64,6 (oC)

- Hieu so nhiet o trung bnh gia

tac nhan say va hi nc cap nhiet:


h

dc

c

t

d2

s1

s1

s2

Hnh 8: Cac kch thc cua


37/61

lcF

loFlF11


2 5 kW th

k3 = 1,1

Nh vay ta chon quat 9-57, No5 luc au la hp ly.

- Cac thong so cua quat va ong c: ta s dung 2 quat 9-57, No5 co cac thong so giong nhau.

Bang 26 : Cac thong so cua quat va ong cThong so Ky Gia Ghi chu



60/61


61/61


- Tien cong che tao lay bang 300% tien vat t : 200.685(ngan ong)

- Gia thanh he thong: 267.580.000 ong

PHAN 3: KET LUAN

oi vi he thong say thung quay nay, viec thiet ke, tnhtoan da nhieu vao cac cong thc thc nghiem, c cho trongnhieu tai lieu khac nhau. Mat khac, do nguyen lieu say la auxanh khong co nhieu tai lieu tham khao, nen trong qua trnh tnhtoan a s dung cac so lieu thay the cua au nanh hoaccac loai ngu coc khac. Viec s dung cong thc, so lieu nhvay khong tranh khoi sai so trong qua trnh thiet ke.

e co the thiet ke c chnh xac ta can lap he thonghoat ong th e kiem tra va chon che o lam viec toi u.ong thi, viec thiet ke he thong da nhieu tren tai lieu lythuyet ch khong co thc te kinh nghiem, nen co the conhieu ieu cha that hp ly, em rat mong c s hng dan,gop y them cua cac thay, co e he thong hoan thien hn.

do an tham khao 5

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