Các loại máy móc, thiết bị trong công nghệ thực phẩm tài liệu, ebook, giáo trình
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Transcript of Các thiết bị máy cơ học trong công nghệ thực phẩm
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Cc thit b my c hc trong cng ngh
thc phm
-
Phn II. My thit b c hc
Chng 2. My v thit b vn chuyn
2.1. M u
a. Cc phng tin vn chuyn cht lng
- Bm th tch: Bm pittong, bm rng kha, bm cnh trt, bm
trc vt
- Bm ly tm
- Cc bm khng c b phn dn ng, bm hng trc, bm xoy
lc, bm tia
- Bm vn chuyn nh sc nn kh quyn
b. Cc phng tin vn chuyn nguyn liu rn
- Vn chuyn lin tc bng ti, gu ti, ni ti, gi ti mc ti, vt ti
- Vn chuyn gin on: t, xe in ng xe gong trc cu, thang
my
c. Nguyn tc la chn my - thit b vn chuyn
- m bo yu cu cng ngh, tnh cht vt liu
- Ph hp vi dy chuyn sn xut, c tinh k thut
- Thit b nh gn, c th b tr hp l ho trong dy chuyn sn xut
- C th vn chuyn nhiu loi vt liu khc nhau.
- D thay th, sa cha
- Gi thnh hp l.
2.2. Vn chuyn cht lng
2.2.1. Bm pittong
- Bm tc dng n
- Bm tc dng kp
- Bm vi sai
a. Bm pittong tc dng n
Nguyn tc lm vic
b. Bm pittong tc dng kp
Nguyn tc lm vic
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c. Bm vi sai
Nguyn tc lm vic
Bm pittong tc dng n
1. Xy lanh 7. Van ht
2. Pittong 8. Van y
3. Cn pittong 9. ng y
4. Thanh truyn 10. B cha
5. Tay quay 11. B ht
6. ng ht 12. Li lc
- Pittong 2 chuyn ng trong xylanh nh c cu chuyn ng gm
tay quay 5 v thanh truyn 4. Dung tch xylanh nm gia 2 im cht ca
pittong bng dung tch ca cht lng trong mi ln hot ng ca pittong
iu kin l thuyt (khng c tn tht th tch)
- Khi chuyn ng sang phi th van 8 ng, van 7 m cht lng t b
11 c ht ln lng xylanh.
Khi pittong n im cht bn phi th hon thnh qu trnh ht
- Khi pittong chuyn ng ngc li th van 7 ng, vna 8 m, cht
lng c y ln b cha 10. Khi pittong n im cht bn tri th on
thnh qu trnh y.
-
- Nh vy sau mi vng quay ca trc truyn ng, tay quay th bm
thc hin c mt chu trnh ht v y.
2.2.2. Bm ly tm
Nguyn tc lm vic
Trong bm ly tm, cht lng c ht v y nh vo lc ly tm xut
hin khi quay bnh gung.
Bnh gung l b phn chnh trong bm c nhiu hnh dng nht nh,
c quay vi tc ln.
+ Cht lng t ng ht 3 i vo tm bnh gung (theo phng thng
gc vi mt phng cnh gung) ri vo rlnh gia cnh gung v quay cng
vi bnh gung. Nh lc ly tm, cht lng bn vo rlnh gia cnh gung vo
thn bm. Rlnh c tit din thay i sao cho khi chuyn ng vn tc cht
lng trong rlnh gim dn n bng vn tc trong ng y 4. ca vo bnh
gung to nn p sut thp v cht lng t b cha lin tc i vo bm. Khi
gung quay, cht lng c ht v y mt cch lin tc, do khc vi
bm pittong, bm ly tm ht v y cht lng rt u n.
+ u ng ht c li 5 ngn khng cho rc bn theo cht lng vo
bm gy tc bm v ng ng. Trn ng ht c van ht mt chiu chn
cht lng trong ng ht khi bm ngng lm vic.
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+ Trn ng y c van mt chiu trnh cht lng dn v bm
gy ra va p thu lc c th lm hng bm v ng c in (khi gung
quay ngc chiu) do bm dng t ngt.
Ngoi ra trn ng y cn t mt van chn iu chnh lu lng
cht lng theo yu cu cn thit.
- Khi khi ng, bm ly tm khng c kh nng ht cht lng t b
cha ln bm v lc ly tm xut hin khi gung quay khng i ui
khng kh ra khi bm v ng ht to chn khng cn thit.
V vy trc khi m my, phi mi cht lng vo y bm v ng ht
hoc t bm thp hn mc cht lng trong b ht cht lng t chon y
bm trc khi m my.
- p ca cht lng do lc ly tm to ra hay chiu cao y ca bm ph
thuc vo vn tc quay ca gung, vn tc quay cng ln th p sut v chiu
cao cng ln.
Tuy nhin khng th tng s vng quay ca trc ln v hn do ng
sut trong vt liu lm gung s tng rt ln, ng thi tr lc tng do vn
tc tng.
i vi bm ly tm mt cp, p sut c th to c l 40 - 45m cn
nu mun tng p sut cht lng ln na th phi dng bm nhiu cp.
2.3. Vn chuyn vt liu ri
2.3.1. Bng ti
+ u im
- Cu to n gin, bn
C kh nng vn chuyn nguyn liu theo hng nm ngang, nm
nghing hoc kt hp nm ngang - nm nghing.
- Vn hnh n gin, bo dng d dng, c kh nng t ng ho
- t gy n
- Nng sut cao, tiu hoa nng lng khng ln lm.s
+ Nhc im
- dc cho php khng cao (16 240 tu vt liu)
-
- Khng vn chuyn c theo ng cong
- D gy bi
2.3.2. Vt ti
+ u im
- Chim t din tch. So vi cc thit b vn chuyn c cng nng sut
th din tch tit din gnang ca ti nh hn.
- Cc b phn ca my nm trong mng kn nn c th ni vi h
thng thng gi. C th vn chuyn vt liu c mi hoc bay hi. C th kt
hp vi qu trnh un nng hoc lm lnh.
- Tc quay ca trc vt tng i ln nn c th kt hp vi ng
c in ring.
- Gi thnh r hn cc loi thit b vn chuyn khc
+ Nhc im
- Chiu di vn chuyn b gii hn 30m
Nng sut b gii hn 100 tn/h
- Khng vn chuyn c vt liu c tp cht, do c th qun vo trc
vt
- Khi lm vic, vt liu b o trn mnh do c th b nghin nt
mt phn hay b phn chia ra theo khi lng ring
- Nng lng tiu tn nhiu hn so vi bng ti
+ Cu to
1. Mng 4. Ca np liu
2. Cnh vt 5. Ca tho liu
3. Trc vt 6. C cu truyn ng
-
+ Cu to ca vt ti
1. Mng ca vt ti c nh, ti phn trn c gn nhng gi trc dng
lm ch cho trc.
Mng ny gm nhng tm 2 4m ghp li vi nhau, ni vi nhau
bng mt bch v bulong
2. Trc vt
Trc vt c cu to rng hoc c, trn gn cnh vt. u trc
vt c lp ln chn cn lc dc trc xut hin khi vn chuyn nguyn
liu.
3. Tu vo cch b tr cnh vt trn trc bn phi hay bn tri trc
m nguyn liu c th di chuyn theo nhiu hng khc nhau.
Nu vt ti gm 2 phn (tri v phi) th c th vn chuyn hai dng
nguyn liu theo hai hng khc nhau.
Vt ti = thp c vn chuyn vt liu; dng bng; dng bi cho
kh ti; cc dnh; cc
4. H thng van
Ti v tr np v tho liu u c van chn thay i kch thc ca
np v ca tho.
Pha cui vt ti c van an ton gip vt liu tho ra d dng. Khi
mng qu y. C th thay van an ton bng ng chy trn.
* Vi vt ti di 3,5m th phi c gi trc treo, mi trc cch nhau
3m.
+ Nguyn tc l/v
Vt liu c a vo t phu np liu. Nh vo chuyn ng ca c
cu truyn ng lm co trc vt quay, vt liu s theo cnh vt chuyn ng
tnh tin ra pha ca tho liu.
2.4. Cc phng tin vn chuyn khc
Vn chuyn vt liu bng khng kh c ng dng vn chuyn vt
liu dng ht, bt, si, vt liu ri.
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ng dng trong cng ngh ch bin ng cc v cc ngnh khc.
Nng sut 800 tn/h, di vn chuyn 1800m
Cao 100m
Mun vn chuyn vt liu phi to ra chnh lch p sut. Da vo
trng thi p sut vn chuyn, c 2 loi thit b vn chuyn nh khng kh
- H thng ht
- H thng y
- H thng kt hp va ht va y
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Chng 3. My v thit b phn loi
3.1. M u
Yu cu chung
- m bo tnh cht k thut cng ngh m nguyn liu cn t c
- Tnh cht ca nguyn liu
+ Vt l: kch thc, hnh dng, mu sc
+ C hc: cng, n hi
+ Sinh hc: mi v, chn
Cc kiu my phn loi
- Phn loi theo kch thc
- Phn loi theo t trng (khi lng ring) tch ht lp, ht thi
hng
- Phn loi theo tnh cht b mt da vo h s ma st khc nhau ca
b mt nguyn liu
- Phn loi theo t tnh. Tch cc tp cht kim loi ra khi nguyn liu
3.2. My phn loi dy cp
1. Dy cp 4. Phu np liu
2. Tang quay 5. Mng hng nguyn liu
3. Nguyn liu
Nguyn tc lm vic
Nguyn liu c a t phu np liu ln dy cp. Nh vo chuyn
ng ca tang quay nn nguyn liu trn dy cp chuyn ng tinh tin.
Gi n: khong cch gia 2 tm cp (m)
d: ng knh dy cp (m)
-
D: ng knh nguyn liu (m)
Khi (n - d) < D nguyn liu i trn cp
Khi (n - d) > D nguyn liu lt xung
mng hng
k tin hnh phn loi l
nmin < Dmin
nmax > Dmax + d
ng dng: Phn loi qu trn, c trn
3.3. My phn loi trc vt
1. Trc vt 4. Tang quay
2. Phu np liu 5. Bng ti
3. Nguyn liu 6. Mng hng nguyn liu
Nguyn tc lm vic
Nguyn liu t phu np liu c chuyn ln bng ti. Nh vo
chuyn ng ca tang quay, nguyn liu c chuyn ng tnh tin trn
bng ti
Khi vt ti lm vic, do cu to ca vt ti l c ng knh ca cnh
vt nh dn t ngt theo chiu chy ca bng ti, nn khong cch gia trc
vi bng ti ln dn. Theo kch thc thay i ca khe h m nguyn liu b
phn loi.
-
ng dng: Phn loi qu cng nh o, l, mn
3.4. My phn loi a quay
Dng phn loi cc loi qu trn, cng, kch thc khng ln lm
thnh 3 - 4 loi c kch thc khc nhau. Mm quay hnh vnh khn 1 gn
vi trc quay 2 bi 8 nan hoa 3. Mm c chiu khum v pha 2 bn. Dc
theo hai bn mm quay, t tm c hnh vng cung c nh 4 bn trong v 5
bn ngoi. Cc tm c vng cung trong v ngoi ny c tm g 6 gn cht
vi thanh st gc 7 bng inh vt 8.
C th iu chnh khe h phn loi bng cch x dch ra vo tm 5 tu
theo yu cu tng nguyn liu. Cc phn quay c gn vi trc, cc phn
c nh c gn vi thn my
1. Mm quay 4. Tm c vng cung trong
2. Trc quay 5. Tm c vng cung ngoi
3. Nan hoa
3.5. My phn loi quang in
Nguyn tc lm vic
Tu theo nguyn liu (u, ng, khoai, c chua).
Da vo nhln hay li lm, chn hay xanh, m b mt ca chng
phn chiu ra cc lung nh sng cng khc nhau.
3.6. My phn loi thu lc
-
Kt hp vic ra v phn loi tch ring cc tp cht nng ct, si, v
cc th nh: rc hoc ht lp
Nguyn liu c vo phu np liu 1, tm chn 2 dng iu
chnh nguyn liu ra vo mng nhiu hay t. Nguyn liu ra i t phu ra
gp ngay lung nc mnh t vi phun 3 cun i theo mng bc thang 4 vo
thng ra. Do tc dng ca dng nc theo chiu nht nh, nguyn liu ra
b phn chia thnh 3 phn theo khi lng ring.
- Phn nh (rc, ht thi, lp) ni ln
- Phn nng (ct, si) chm xung di
- Phn c khi lng ring trung bnh (ht tt) l lng trong cht lng
Yu cu ca vn tc dng nc khng qu nhanh lm o ln s phn
chia, nu vn tc dng nc yu th khng kh nng phn chia cc loi
nguyn liu.
Cc phn nh ni ln c dng nc cun vo mng 5 phn nng
lng xung lung 6 v c vi phun 7 cun vo mng 5. Cc ht tt ri vo
bung 8 v c vi phun 9 cun theo ng 10 ra sng lc ra li v tch
nc cho ro.
Nc ra l dng mt ln c tp trung vo b cha, ri dgn bm
11 bm qua vi 3 dng li do tit kim c nc v gim hao tn
cht kh.
Tp cht c tho ra theo chu k v nc bn c thay ra theo chu
k.
u: Phn loi tt, cu to n gin, nng sut ln 4 tn/h
Nhc: Kh phn thnh nhiu loi hao tn, ph phm ~ 0,2 - 0,5%
3.7. my phn loi kiu sng
- Mguyn l lm vic chung ca cc loi sng l to s chuyn ng
ca cc vt liu ri nm trn mt sng, cc vt liu c kch thc nh s lt
qua mt sng, vt liu c kch thc ln nm li trn mt sng.
-
- S phn loi c th c tin hnh t kch thc nh n ln:, Kch
thc ca l sng to dn theo chiu di ca mt sng, (cng l chiu chy
ca nguyn liu) v sng thng b tr ni tip.
+ u im: ca phng php ny l cu to n gin, d tho lp.
+ Nhc im: din tch mt phng phi rng, cht lng c phn
loi thp, mt sng chng mn
- S phn loi c th c tin hnh t kin thc ln n nh bng
chch b tr cc sng xp chng nn nhau
+ u im: cht lng phn loi tt Mt sng lu mn
+ Nhc im: Tho lp kh.
- khc phc nhc im ca hai phng php trn v pht huy u
im ca hai phng php c th kt hp mt sng va b tr xp chng, va
b tr ni tip.
a. My sng lc phng
Nguyn tc lm vic
sng lm vic c th yu cu vt liu trn di sng phi chuyn
ng thnh mt dng lin tc.
Khi sng tin th vt cng tin (lc qun tnh < lc ma st)
Khi sng li th vt liu cng trt tng i trn b mt sng (lc
qun tnh > lc ma st)
Cn phi to cho sng c gia tc tin v gia tc li khc nhau, thng
qua b phn truyn ng l tay quay thanh chuyn v c cu lch tm.
+ u i: Nmg sut, hiu sut cao
Cu to dn gin, gi thnh thp
S dng v sa cha tin li.
Nhc im: Khi chuyn ng c cu tp khng cn bng -> ti
trng ng ln -> nh hng ti b my
-
a.
1. Khung sng 5. ng c in
2. Thanh n hi 6. B my
3. Tay bin 7. Trc lch tm
4. B truyn ng 8. Gi trc
b. My sng phn loi bng li
1. Bung cha nguyn liu 5. Cc tm li sng t nghing
2. Qut ht bung lm sch 6. Qut ht bung phn loi ht
3. Ca khng kh vo 7. Cc tm mt phng nghing
4. Bung tch bi lm sch ht 8. Ca ra ca ht l phn loi
-
b. My sng phn loi bng li sng v khng kh
Theo chiu cao ca my c th chia thnh 3 phn:
- Vng phn loi bng khng kh lm sch ht
- Thng sng phn ht theo ln thnh 3 phn ht
- Vng phn loi bng khng kh chia tng loi ht theo ln v
thnh cc phn ring theo t/c kh ng lc.
Ht i vo bung 1, qut 2 ht khng kh ko nguyn liu vo ng 3,
v cun theo cc hn hp nh. Hn hp ny c lng bung 4 v t y
chng c tch ra khi my. Khng kh sch bung 4 c qut thi vo
ln th 2 lm sch ht. Nh vy qut lm vic theo nguyn tc tun ohn
kn ca dng kh.
thng sng 5 khi ht c phn ra mt s thnh phn khc nhau
theo chiu rng v dy ca ht.
Cc thnh phn ny vo cc ngn khc nhau ca vng phn loi
bng khng kh pha di. Qut 6 ht khng kh qua lp sn phm ang
trt theo mt phng nghing 7. Tng ng vi vn tc khng kh khc nhau
ti nhng ngn ring ca bung lng 8 c cc hn hp khong, ht bn, ht
sch v hn hp nh c lng xung.
Thng sng chuyn ng tnh tin nh c cu thanh truyn hoc c
cu lch tm.
-
Chng 4. My ra v lm sch
4.1. Gii thiu chung
Ra v lm sch l khu u tin ca qu trnh ch bin thc phm.
a. Cc yu t nh hng n qu trnh ra
- Tc nhn dng ra c th l nc hoc hi.
Ra bng nc tt hn ra bng hi v nc c th cun i cc vi sinh
vt, cc cht bn bm trn b mt nguyn liu hay bao b.
Ra bng nc nng c tc dng dit cc vi sinh vt tt hn ra bng
nc lnh, tuy nhin i vi mt s loi bao b hay nguyn liu vic ra
bng nc nng c th nh hng xu ti cht lng nguyn liu v bao b.
- Cht lng ra tng khi lng nc ra cng nhiu, tuy nhin tch
kim nc th nn c mc hn ch nc ra nht nh
1kg nguyn liu - 1 t nc
Chai, l c th tch V - V lt nc ra
- Thi gian ra cng di th cht lng ra cng cao. Nhng nh
hng ti nng sut thit b v cht lng nguyn liu. Ngoi ra, thnh phn,
nng dung dch ra, p lc, vn tc nc ra, hng, cu to dng nc
phun u c nh hng n cht lng ra. Mt khc cu to thit b ra,
phng tin ra cng quan trng.
b. Nguyn l chung cc loi my ra
m bo hai giai on ngm v xi
- Mc ch qu trnh ngm l cc cht bn bm vo vt cn ra b
ra. Thi gian qu trnh ny ph thuc vdo tnh cht ho l ca cht bn, sc
bm ca n vo vt cn ra, kh nng tc dng ca dung dch ra.
- tng hiu qu qu trnh ngm c th o trn dung dch ra (bng
cch khuy hay thi kh), tng nhit hay dng dung dch kim.
- Mc ch ca qu trnh xi l x sch cht bn bm trn vt ra.
- tng hiu qu qu trnh s dng lc c hc, nhit , cht ho
hc hoc phi hp cc bin php trn.
4.2. Ra nguyn liu
-
- My ra thng quay hnh nn
My ra thng quay hnh nn c ch to theo nhiu kiu khc nhau
lm vic theo nguyn tc ngm hoc xi.
V thng quay c th bng g hoc bng kim loi, hnh tr hoc hnh
nn, t nghing hoc nm ngang
Phng php truyn ng cng khc nhau, tu mc ch s dng v
ch to.
- Nguyn tc lm vic
Nguyn liu ra lin tc i vo my qua mng 1. Thng quay 2 lm t
thanh kim loi trn hoc dt ghp khng st nhau. Khi nguyn li vo,
thng s quay v chuyn dn nguyn liu t u vo n u ra, do c im
cu to thng hnh nn.
Do trong thng quay c cc tm dn hng nn m bo nguyn liu
ra ra theo mng liu ra.
Nc trong thng ra c duy tr mc ngp chm nguyn liu ra.
Nc vo v ra thng ra lin tc, v cn bn c tho ra ngoi theo
ng 5.
Vn tc thng quay khong 75 - 80 vng/pht, nh trc 6 nhn truyn
ng qua tang quay 7 t ng c in v b phn gim tc
- ng dng: Ra c nguyn con, rau, c, qu
-
1. Mng nguyn liu vo 4. V thng
2. Thng quay 5. ng tho cn
3. Mng nguyn liu ra 6. Trc quay
7. Tang quay
4.3. Ra bao b
My ra hp st kiu treo
1. Mng a hp vo
2. Bnh rng hnh sao th nht
3. Trc rng
4. Vi phun nc
5. Bnh rng hnh sao th hai
6. Bnh rng hnh sao nh
7. Mng a hp ra
8. ng nc thi
9. Dy treo
Nguyn tc lm vic
-
Hp c a vo theo mng 1. Bnh xe hnh sao th nht a hp i
trong my theo chiu ngc chiu kim ng h. Nc nng theo trc rng
ca bnh xe a theo 8 nhnh vo 8 vi phun phun vo cc hp. Trong
qu trnh ra bng nc nng hp xung quanh trc ca bnh xe hnh sao th
nht mt gc ~ 3000. Sau hp c chuyn sang bnh xe hnh sao th hai,
chuyn sang giai on phun hi nc nng. Qu trnh din ra tng t khi
ra bng nc nng. Bnh xe hnh sao nh a cc hp ra ngoi theo mng
a hp ra.
Nc ra xong c tho ra ngoi theo ng tho nc thi.
My c treo bng dy treo ln trn nh
Nng sut 350 hp/h
My r treo ch dng vi hp hnh tr trn
4.4. My lm sch nguyn liu
- My lm sch v c
- My bc v hnh kh
- My nh vy c
- My ngt cung qu
- My tch ht c chua
-
Chng 5. My v thit b lm nh nguyn liu
5.1. My v thit b nghin
Qu trnh lm nh nguyn liu l qu trnh gia cng c hc nhm ph
v c cu nguyn liu, chuyn chng sang dng nh hn.
Qu trnh nghin ngh vt liu trong my nghin l nh cc lc c
hc. C th phn loi cc dng tc dng c hc nh sau:
Ch xt Va p
- p: di tc dng ca ti trng, vt liu b bin dng v c th tch.
Khi ni ng sut trong vt liu ln hn gii hn bn nn th vt liu b ph
v. Kt qu ta thu c cc cc vt liu c kch thc < kch thc vt liu
ban u c hnh dng khc nhau
- B: Vt liu b ph v do lc tp trung tc dng ti 1 ch t lc.
Kch thc ca vt c th iu chnh theo mong mun.
- Va p: Vt liu b ph v di tc dng ca ti trng ng khi ti
trng tp trung th tng t nh b, khi ti trng phn b ra ton th tch vt
liu th tng t nh p.
-
- Ch xt: Vt liu b ph v do tc dng ng thi ca lc p v lc
ko. Sn phm thu c dng bt
My nghin ba
* Qu trnh nghin c thc hin do:
+ S va p ca ba vo vt liu
+ S ch xt ca vt liu vi thnh trong ca v my
Cc ht vt liu nh lt qua li phn loi v c ht ra khi my,
cc ht vt liu to cha lt qua li li c ba tip tc nghin nh
* K qu trnh nghin
ng nng ca ba khi quay > cng lm bin dng ph v vt liu
Khi nghin vt liu c to ba khi lng ln
Nh ba khi lng nh
- Ba c khi lng ln c trng lc G = 200 - 700N
Roto quay = 25 - 60m/s
Dng nghin tinh to ht sn phm d = 1 - 5mm
- Ba c trng lc mi ba G = 5 - 10N
Roto quay = 100m/s to ht sn phm d = 10 - 10m * Cu to: My nghin c m nghin ph trn thnh trong ca v my
lm tng thm kh nng ph v vt liu di tc dng va p ca ba, v tc
dng ch xt ca mi nghin.
- M nghin ph c t di ghi v tr ca np liu
- Ghi c tc dng phn phi u vt liu theo chiu rng my hn ch
kh nng vng liu ln ba khi p.
- Trn cc a c treo 2 ba. Cc ba ny p trn cc mt phng qua
cc khe ghi lp sut theo b rng my. Vt liu sau khi nghin nh s lt
qua li ra khi my, cn cc ht vt liu to s tip tc nghin cho n khi
nh th thi.
Np my c th m ra thay ba hoc li
-
1. Phu np liu
2. Tm ghi
3. Trc quay
4. Ba
5. Np my
6. Li sng
7. M nghin ph
8. a treo ba
5.2. My ct thi
Hiu qa ca qu trnh ct thi ph thuc
- B phn ct
(Kiu dng li dao, c im chuyn ng ca li dao) v m bo
yu cu v kch thc, hnh dng, b mt ming ct.
-
Cc loi li dao thng dng
Cc kiu hnh dng ct thi
+ iu chnh b dy Kch thc a, b ph thuc nguynliu
+ iu chnh b dy v kch thc Kch thc b ph thuc nguyn liu
+ iu chnh c
a b ; theo yu cu cho trc
ct vung
hoa ngi sao; trn
My thi lt
My thi lt a quay nm ngang, t ng
Nguyn liu c a vo ca vo nguyn liu
Trong khoang thi c t a quay trn c cc li dao khi my
lm vic a quay lm cho li dao ct nh nguyn liu. Do di mi li
dao c khe h nn nguyn liu c ct s ri xung di theo ca sn phm
ra i ra ngoi.
Ton b my lp trn gi
-
1. Khoang thi
2. Ca nguyn liu vo
3. Ca sn phm ra
4. a quay
5. Trc quay
6. Gi my
7. Dao ct
5.3. My ch nguyn liu
My ch dng phn chia nguyn liu mm nh c chua, chui,
hoc cc loi qu cng l chn mm thnh 2 phn bt qu v bl.
Nguyn l lm vic
To co nguyn liu lc ly tm lm cho nguyn liu vng ln thnh
my c c l nh. Di tc dng ca lc ly tm lc p, lc ch xt,
nguyn liu b nh ti nh.
-
Dch bt qua l sng ra ngoi, phn cng gi l ph liu cn li trong
my s c dn ra ngoi.
Nu xp nhiu my ch lm vic ni tip th t nguyn liu u c th
phn chia thnh nhiu loi thnh phn khc nhau.
Cu to ca my ch
1. Trc 6. Mt sng
2. ng kim loi khng g bc ngoi 7. Ca np nguyn liu
3. Nam hoa 8. Mng hng sp
4. Cnh ch 9. Ca tho ph liu
5. Gi trc 10. V lng
* M t cu to: gm 2 phn
- Cnh ch l nhng thanh thp lp trn trc quay v sng trn c nh
bao bc xung quanh. S cnh ch trn trc thng l 2 hoc 4. C th thay
th cnh ch bng cc tm thp lp theo ng xon. Tc dng ca cnh ch
l to lc ly tm? sc quay ca nguyn liu, thc hin qu trnh ch nh
nguyn liu v thi ph liu.
- Sng c cu to hnh nn, lp c nh c th m i ra c, lm t
tm kim loi mng khng g v c c l. sng chu c lc ln ca
-
nguyn liu tc dng t bn trong, bn ngoi sng c gia c bi nhiu np
thp dy. Tc dng ca sng l phn chia nguyn liu l gia cng thnh 2
phn: tht qu v ph liu.
* Nguyn tc lm vic
Khi my ch lm vic. Nguyn liu t ca nguyn liu vo i vo
khoang ch. Do trc quay lm cho cnh ch quay v nguyn liu c ch
xt vo mt sng. Phn bt hay tht qu i qua cc l sng vo mng hng
sn phm. Ph liu i ra ngoi theo ca tho ph liu.
* Khong cch gia cnh ch v sng c th iu chnh c bng
cch y trc quay v pha trc hay pha sau bng cch iu chnh v lng.
S iu chnh ny c th thc hin ngay trong qu trnh lm vic ca my.
* nng cao hiu qu lm vic ngi ta lp cnh ch nghing mt
gc 200 - gc nghing hay gc lch. Gc lch cng ln nguyn liu qua
my cng nhanh, lc ly tm tc dng ln nguyn liu c thi gian ngn,
lng bl cng nhiu.
* S vng quay ca trc cng c nh hng n hiu qu lm vic.
-
Chng 6. My khuy trn
6.1. Khuy trn cht lng
Khuy trn l qu trnh c hc c s dng ph bin trong cc qu
trnh ch bin thc phm.
+ Mc ch ca trnh khuy trn
- Tng cng qu trnh truyn nhit
- Trn cc hn hp to ra s ng nht
- Ho tan cc cht rn trong cht lng
- Tng cng phn ng ho hc trong cht lng
+ Nhng qu trnh chnh gm
- Khuy trn cc cht lng: Lng vi lng
Rn vi lng
- Nho cc loi bt nhlo: bt + lng
- Trn cc cht kh
Mc ch ca qu trnh khuy cht lng trong CN thc phm
- Lm tng qu trnh truyn nhit trong thit b truyn nhit c bit l
cc trng hp i lu t nhin km
ng c tnh lm vic ca cnh khuy
: h s truyn nhit (kcal/m2. h.) P/v: nng lng khuy trn mt n v th tch cht lng. Khi P/v cng
ln th cng ln.
-
(1) ng c tnh ng vi hit b truyn nhit ng xon rut g
(2) ng c tnh ng vi thit b truyn nhit 2 v
- Thc y s ho tan ca cc cht rn trong cht lng nh vic ho
tan ca cc cht rn trong cht lng nh vic ho tan ng, mui
Lng cht rn ho tan trong cht lng tun theo quy lut chung ca
qu trnh trao i cht
G = k. Ftb . .Ctb (kg)
K: H s ho tan Error!
H s ho tan tng khi chun s Re tng
Ftb: din tch trung bnh ca b mt cht ho tan (m2)
: thi gian ho tna (h)
Ctb: hiu s trung bnh ca nng cht ho tan v dung dch (kg/m3)
6.2. My nho bt c
6.2.1. My nho c trc quay nm ngang
1. Thng nho 5. Cnh o
2. Phu nguyn liu vo 6. Trc quay
3. Tm chn 7. Np
4. Ca nguyn liu ra 8. Bulong
Nguyn l lm vic
-
Nguyn liu c a vo t phu nguyn liu vo. Thng nho c
t nm ngang, trong c trc quay v cc nh o. Tm chn m bo
coh cc vt l khng ri vo thng nho trogn qu trnh lm vic v m bo
an ton cho cng nhn khi thao tc. Sn phm sau khi c nho trn c
y ra ca nguyn liu ra
My lm vic gin on, sau mi chu k lm vic, c th m np my
nh tho cc bulong, v sinh
ng dng nghin tht, rau, bt, ht
6.2.2. My nho c trc quay thng ng
1. Thng nho 5. Bnh rng c nh
2. Cnh nho 6. Trc quay chnh
3. Trc cnh nho 7. Thn my
4. Bnh rng hnh tinh
Nguyn l lm vic
Nguyn liu c a vo thng nho. Cnh nho gn vi trc quay.
Khi my lm vic, bnh rng hnh tinh s chy quanh bnh rng c nh nh
-
trc quay chnh. Bnh rng hnh tinh s truyn chuyn ng n cnh nho
do vy nguyn liu c o trn.
My lm vic gin on, sau mi chu k lm vic, sn phm c ly
ra v c th v sinh my
ng dng trong sn xut sa hp, bt bnh, ko, kem
6.3. My trn kh
1. Thng nho 7. Hp gim tc
9, 2. Cnh nho 8. Mt in
4, 3. Trc quay
6, 5. Bnh rng
Nguyn liu c a vo thng trn. Nh vo hai cnh o ch Z
gn trn 2 trc quay ngc chiu nhau v c tc khc nhau m nguyn
liu c o trn
Tc trc l 44 vng/pht
95 vng/pht
-
Chng 7. My v thit b phn tch h thng ng nht
7.1. My v thit b lng
Lng l qu trnh tch pha rn ra khi pha lng mt cch n gin nh
vo lc trng trng. Dung dch huyn ph sau khi a vo b lng, di tc
dng trng lc, cc ht rn s lng xung di to thnh lp bl, pha lng
bn trn s c ly ra bng phng php gn hoc dng vi tho ra ngoi.
Thng lng c th lm vic gin on, bn lin tc hoc lin tc.
7.1.1. Thit b lng gin on
Dung dch huyn ph c a vo thng lng, di tc dng ca
trong lc, theo thi gian, cc ht pha rn s lng xung y thit b. Pha lng
s c tho ra theo van dn, sau cn cng c tho ra theo mt van
khc y thit b.
u im cu to n gin nhng nng sut thp.
7.1.2. Thit b lng bn lin tc
Dung dch huyn ph c a vo thit b lin tc vi vn tc khng
ln, nc trong c tho ra lin tc, cn y c tho ra theo chu k.
Cc loi thit b lng bn lin tc
* Loi tm nghing
Tm chn c tc dng hng cho cht lng chy t di ln sau
chy t trn xung.
Cn c ly ra cc phu y thit b
* Loi hnh nn
-
Hn hp rn - lng lin tc i vo trong thng c xp cc tm ngn
hnh nn. Mi nn l mt tng ring bit nc trong theo cc khe gia cc
nn i vdo ng trung tm ri c y ra ngoi. Cn tp trung trn b mt
nn ri trt xung y, c tho ra ngoi theo chu k.
cn trt c th gc nghing ca nn ln hn gc ri t do ca
cn
7.1.3. Thit b lng lin tc
Hn hp rn - lng c a vo thit b lin tc, cn v nc trong
c tho ra lin tc
* Loi hnh phu
-
B hnh phu c gc y = 600. Hn hp huyn ph i qua a phn
phi vo b. Nc trong trn vo mng (3) ri i dn ra ngoi. Nu ng tho
cn tc th tin hnh thi kh nn thng ng.
* Loi rng co
B cha hnh tr, c y hnh. C trc, quay v trn trc quay gn
cnh khuy, trn cnh khuy c gn rng co bng thp. Hn hp huyn ph
lin tc, i vo thit bl nc trong c tho ra lin tc theo mng tho
nc. Trc cnh khuy quay vi vn tc rt chm khng nh hng ti
qu trnh lng ~ 2,5 - 20 vng/pht. Cn lng xung pha y c cc rng
co trn cnh khuy dn vo tm thit b ri theo ng y thit b dn ra
ngoi.
Nng sut thit b ln 300 tn/ngy m.
7.2. My v thit b lc
Lc l qu trnh phn ring huyn ph thnh nc trong v bl (cn)
bng cch cho huyn ph i qua mt lp vt ngn, cc ht rn b gi li trn
b mt vt ngn cn nc trong i qua. khc phc c tr lc ca vt
ngn (lc ban u) v tr lc ca vt ngn + lp bl (cc giai on sau) th
nc trong cn c mt p sut do bm hoc ht chn khng. n mt giai
on nht nh th phi tin hnh ra vt ngn, ly bl ra.
- Da vo phng php lm vic c hai loi thit b lc
My v thit b lm vic gin on lin tc.
+ Da vo kh nng to thnh hiu s p sut
-
- My lc chu tc dng ca p sut
- My lc chn khng
+ Da vo cu to: My lc khung bn
My lc ti, my lc thng quay
My lc khung bn
ng dng: Cng ngh sn xut bia, ng, nc qu
- Lc huyn ph nng khng cao
- Lc huyn ph nhit cao, khng cho php lm ngui
M t cu to
My lc khung bn gm c 1 dly khung v bn c cng kch thc
xp bn nhau. Khung v bn c t trn 2 thanh nm ngang nh cc tai
treo, gia khung v bn c vi lc.
p khung v bn ngi ta dng mt u v tm y khng chuyn
ng, mt u l y c th dch chuyn c nh tay quay. Khi vn tay
quay th tm y c th dch chuyn tnh tin.
Qu trnh lc
Dung dch lc c p sut 3 - 4atm (dng bm) theo ng ng dn i
vo cc rlnh ti tng khung mt. Dung dch s qua lp vt liu lc sang bn
v theo cc rlnh dc trn bn chy xung di, tp trung theo mt ng
rlnh ri theo vi chy ra ngoi. Cn s c gi li trong khung gia 2 tm
nguyn liu lc.
Lp cn cng nhiu th tc lc cng chm v p sut a vo lc
cng tng. Khi p sut tng n mc cc i v khng thay i chng t cn
bn trong khung l y, ta phi tin hnh ra bl v tho cn.
Qu trnh ra bl nh sau: ngng np huyn ph, m cho nc ra vo.
Khi ra xong ngi ta ni quay cho khung v bn tch ra, bl ri xung mng
di ri ly ra ngoi. Vt liu lc c git sch s dng li.
u: Nng sut lc cao, hiu qu cao
Nhc: Thao tc nng, vi lc chng mn, rch, thi gian cho cc thao
tc ph ln
-
Cu to my lc khung bn
1. Khung lc 6. Tm y di ng
2. Bn lc 7. Thanh nm ngang
3. Vi lc 8. Tay quay
4. Chn my 9. Mng cha nc lc
5. Tm y c nh
1. ng rlnh dn huyn ph 1. ng rlnh dn huyn ph
2. ng rlnh dn nc ra 2. ng rlnh dn nc ra
3. Phn rng 3. ng rlnh nm ngang
4. Phn khung 4. ng rlnh dc
5. Tai treo 5. Tai treo
-
7.3. Cc my ly tm
Cc my ny phn ring huyn ph thnh pha rn v pha lng nh vo
lc ly tm sinh ra do qu trnh quay dung dch. Cc my ly tm c s
dng vi cc dung dch huyn ph c nng cao, khng th dng phng
php lng hay lc c.
Phn loi my ly tm
- Theo yu t phn ly c my ly tm thng
My ly tm cao tc
- Theo cng dng c: My lc ly tm
My lng ly tm
My phn ly nh tng
- Theo phng php co bl: tho bl bng tay, bng vt xon, bng dao
co, thanh gt, thu lc
- Theo kt cu cc im ta ca trc kiu ng, kiu treo
- Theo v tr ca trc nm ngang, thng ng, nm nghing
- Theo qu trnh lm vic gin on, lin tc
ng dng
My ly tm c s dng rng rli trong ngnh ch bin thc phm
CNSX ng phn ring ng v v ng
Nc qu: phn ring nc trong v bl
Ch bin sa: Phn ring sa v phn m (cht bo)
My ly tm trc thng ng lm vic gin on c cc giai on lm
vic nh sau:
- M my, cho hn hp huyn ph vo
- Nh vo lc ly tm, huyn ph c phn ring thnh bl v nc
trong (pha rn v pha lng)
- Ngng my, tho bl
- Hn hp huyn ph c th c a vo thng ly tm trc khi my
lm vic, khi my bt u quay cha t tc n nh hoc khi my l t
n tc n nh.
-
Nu c yu cu ra bl th trong qu trnh ra, vn tip tc chy my
tc lm vic tch v p nc ra ra khi bl
Cu to my ly tm
1. Thng quay ly tm
2. Trc quay (ni ng c vi thng quay)
3. Mo t in
4. Gi trc
5. Khung treo my
6. V ngoi thng quay ly tm
7. Nan hoa
8. Chp
7.4. Cc my p
Cc my p c s dng tch cht lng v khi nguyn liu rn.
Tu vo mc ch s dng, ngi ta dng phn lng, phn rn hay c hai
+ Cc yu t nh hng n qu trnh p
-
- p sut p: Khi p sut p tng th hiu qu p tng. n mt gii
hn nht nh, khi p sut tng, mao qun trong nguyn liu b tht li lm
cho nc khng thot c ra ngoi.
- Thi gian p: Vi cng p sut p, khi thi gian p tng th hiu qu
p tng. n mt gii hn nht nh v thi gian th khng nh hng n
hiu qu p.
- Nhit s ch: Khi nhit tng th nht ca dch nc p
gim, nc p d chy ra hn do hiu sut p tng. Nhng nhit tng
cng lm nh hng n cht lng nguyn liu.
- Phng php s ch nguyn liu. tng hiu sut p, ngi ta dng
cc phng php c hc lm ngn mao qun cc phng php ny gm
ct, x, nghin
+ Phnloi cc my p
- Theo nguyn tc lm vic c my p lm vic gin on, bn lin
tc, lin tc
- Teo cu tao ca my p trc vt, my p vt xon, my p thu lc
+ My p trc vt
B phn lm vic chnh ca my l trc vt c ng knh cnh vt ln
dn hay trc vt c bc vt nh dn, t trong xylanh nm ngang c c l.
Nguyn liu p khi di chuyn theo trc p chu p sut tng dn.
-
Chng 8. My rt v in sn phm vo bao b v cc my ghp np
bao b
8.1. C cu rt theo th tch nht nh
My rt v in sp vo bao b l mt khu quan trng i vi ngnh
sn xut hp
Yu cu ca my l phi thc hin qu trnh rt nhanh, chnh xc, v
sinh, c th c yu cu c bit v cch xp sp trong hp v cht lng sn
phm
i vi cc loi sn phm khc nhau th cc my rt cgn khc nhau
cho ph hp vi sn phm
- Sn phm dng lng: ru, bia, nc gii kht
- Sn phm dng st: sa c, sa chua
- Sn phm gm c ci v nc: tht u, ng ht
Phn loi cc my rt v in sn phm
- Theo mc t ng: bn t ng v t ng
- Theo phng php vn chuyn bao b, i thng hay i vng
- Theo phng php rt sn phm
Rt theo th tch hay rt n ngn
Rt theo kiu t chy hay dng sc ht
8.1.1. C cu rt theo th tch nht nh
Qu trnh lm vic ca c cu rt theo th tch nht nh gm c 2 giai
on
- Giai on ong: y sn phm vo cc ong (th tch khng i),
giai on ny l giai on t chy
- Giai on rt: chuyn sn phm t cc ong sang bao b, nu sn
phm dng bt nhlo th phi dng sc ht chn khng
C cu rt v cc ong dng cho cht lng
-
8.1.2. C cu rt n ngn quy nh
C cu ny c s dng trn dy chuyn
Sn phm ng hp: C ci v nc
Sn phm ng chai: Nc
C cu rt n ngn quy nh dng cho rt chai
1. Thng cha nguyn liu
2. ng dn nguyn liu
3. m cao su
4. ng bao ngoi ng dn
5. u p trn
6. ng thot kh
7. Nt y ng dn
8. L xo
Nguyn tc lm vic
y thng cha nguyn liu c ni vi ng dn nguyn liu. ng bao
ngoi ng dn c ni vi u p trn, c th trt dc theo ng dn
nguyn liu
u di ca ng thot kh c nt
-
- v tr khng lm vic, nt ny s bt cht ming chy ng bao
ngoi ng dn nh h thng lxo
- v tr lm vic: ming chai s tip xc vi u p trn v y u
p trn ln trn, lm coh ming chy tch khi nt v cht lng chy vo
chai. Khng kh trong chai thot ra ngoi qua ng thot kh. m bo qu
trnh thot kh c thc hin th u trn ca ng thot kh phi cao
-
hn mc cht lng trong thng cha.
Khi cht lng chong chai n gn quy nh, khng kh trong chai
khng cn li thot lm cho qu trnh rt dng li.
8.2. My ghp np
Mc ch l bo qun nguy liu v sn phm c lu di, d
dng trong vic vn chuyn, phn phi, ngi ta s dng hp st, ghp m
kn
Chai l thu tinh ghp np st..
8.2.1 Cc loi mi ghp
dng ghp np cho cc loi hp bng st ty hoc bng kim loi
khc, to mt vnh ni gia np vi thn hp gm 5 lp kim loi cun li vi
nhau, gia lp ny c lp in bng gioang cao su chng h. Mi ghp
n: dng ghp cc lp kim loi c m cao su hoc nha hoc lil vo ming
bao bi thu tinh nh vic bp cht np vo vnh g ca ming bao b.
8.2.2 Nguyn tc truyn ng ghp:
- Truyn ng ghp 1 trc
- Truyn ng ghp 2 trc
8.2.3 Cu to ca mt s my ghp np.
Myghp th cng: hp vo v ra, tin hnh qu trnh ghp u phi
c ngi iu khin.
My ghp bn t ng: qu trnh ghp np c t ng hon ton,
hp vo v ly ra bng ty. Loi ny ph bin Vit Nam
My ghp t ng: ton b qu trnh a hp vo, y np, tin hnh
qu trnh ghp gm 2 giai on u c t ng ho. Loi ny ph bin
trn th gii
My ghp t ng c ht chn khng: loi ny thng l1 trc, ph
bin trong cc nh my hp
Phn III: Cc Thit B Nhit
Chng 9. Cc thit b trao nhit
-
Nu - chn - hp - lm ngui
Qu trnh ch bin thc phm lun c cc qu trnh x l nhit qu
trnh gia cng tip theo thun li v c hiu qu cao.
Qu trnh x l nhit lm cho qu trnh thu phn tt hi, mu xc,
mi v t c nh , mun bo qun c lu hn.
Vai tr ca cc thit b nhit trong ch bin thc phm
- Dng cc qu trnh ch bin: lm chn, hp
- Dng cho cc qu trnh bo qun: sy , nng
- Dng cho cc qu trnh tit trng
Qu trnh truyn nhit xy ra nh sn phm thc phm tip xc vi b
mt truyn nhit, c th gin tip hoc trc tip
Phn loi cc thit b trao i nhit:
- Theo phng thc lm vic: gim on lin tc
- Theo p sut lm vic : C p sut thng
p sut chn khng
- Theo cu to: ng chm
Loi hai v
ng xon rut g
9.1. Thit b lm vic gim on p sut thng
* Thit b un nng 2 v
Cng dng: dng un nng mt dung dch no bng hi thng
qua b mt truyn nhit l v ca thit b
C th s dng thit b ny un nng nc, chn m, c chua
-
Ch thch cu to thit b:
1- V trong 6- Van tho nc ngng
2- V ngoi 7- Van hi an ton
3- Bung hi 8- p k
4- ng dn hi vo 9- Chn
5- ng thi hi 10- B phn nghing ni tho sn phm ra
M t thit b
- Thit b 2 v bn trong c ch to bng thp khng d hoc trng
men, v ngoi lm bng thp khng g to thnh phng hi un nng, c
th dng lp cch nhit buc bn ngoi ng dn hi nc nng
- Hi nc ngng theo ng thi hi i ra ngoi vo bnh ngng t.
Nc ngng khng cn thit s theo van tho nc ngng i ra ngoi.
- Ngoi ra ni 2 v c van hi an ton, p k. Ni c t trn chn
v sau mi chu k lm vic c th a sn phm ra ngoi nh b phn
nghing ni tho sn phm ra.
Nguyn tc lm vic
Cho dung dch vo ni, tho ht nc ngng trong phng hi, ri ng
van tho nc ngng. T t m van hi cho ng dn hi vo, khi p sut
phng hi t ti p sut lm vic th kho van hi 4 nh bt li, duy tr p
sut lm vic cho n khi nhit , thi gian t theo yu cu ca sn phm.
tng cng kh nng truyn nhit ngi ta thng lp thm cnh
khuy
9.2. Thit b lm vic lin tc p sut thng
Cng dng chn hp cc loi nguyn liu cng to, o, l, mn
9.2.1. Thit b chn hp kiu bng ti
Nguyn l hot ng
My gm c thng kim loi kn c np c th m ra khi cn thit.
Trong thng t h thng bng ti, trn mt bng l nguyn liu mt bng ti
thng cu to l xch ti chuyn ng c g 2 bn gi sn phm.
Nguyn liu c a vo t ca vo 4 v ra mng 5. Gia 2 nhnh ca
-
bng ti, t h thng phun hi c p sut t 3 - 4 at. Trn np c t knh
quan st kim tra nc dung dch chn c lin tc b sung
1 - Thng kim loi 4- Phu np liu
2 - Bng ti 5 - Ca ra sn phm
3- Nguyn liu 6 - ng phn hi
9.2.2. Thit b chn hp kiu thng quay
Dng chn cc loi nguyn liu c qu c kch thc nh, thi gian
chn hp tng i di
C cu lm vic gm thng trn bng thp l, trn b mt c cc l
nh 3 - 4mm, bn trong c gn cc l thp kim loi hnh xon c lm cho
nguyn liu c chuyn dn t u ti cui v ra khi thit b.
Thng t trn bnh xe quay c nh trc ph thng c ngm
trong nc nng c cc ng phun hi. Thng c bc v hnh tr bn ngoi
9.3. Thit b un nng trong ng kn, lm vic p sut thng.
-
Dng cho nguyn liu dng lng. Cht ti nhit l nc nng, hi.
Thit b gm c cc loi ng rut g, ng chm, ng lng ng
u: Thi gian truyn nhit nhanh, b mt truyn nhit ln
9.3.1. Thit b un nng kiu ng chm
Cng dng: Dng un nng bt qu nghin, nc c chua.
H s truyn nhit ln ph thuc vo vn tc ca sn phm v p sut
hi (1 - 1,5 at)
Ch thch thit b
1, 2. Mng ng
3. ng kim loi
4. Thn thit b hnh tr nm ngang
5, 6. Np hai u
7. Vch ngn
8. Van tho nc ngng
9. Ca tho sn phm ra
Nguyn l lm vic
Thng thng trong sn xut thc phm loi thit b ny c khong 64
ng. ng knh mi ng 30 - 32mm. Chiu di thng 2m. Vch ngn 7
ni cc chm ng vi nhau. Hi c dn vo khong khng gian gia v v
cc ng sn phm cn un nng c lin tc bm qua cc chm ng. Sn
phm i qua ng c t nng theo chiu di ng nhn vi h s ln i.
H s truyn nhit ca thit b loi ny t 350 - 2.200 (w/m2 )
Nng sut khong 10 - 14 tn/h
9.3.2. Thit b kiu ng lng ng
Cng dng dng un nng nc qu, dch ng hay dch mui
hoc l lm ngui cc dch trn bng tc nhn lnh. Cht ti nhit l nc
hoc hi nc c p sut P = 2 - 3 atm
H s truyn nhit K = 500w/m2
Din tch b mt truyn nhit 4 4,5m2
Nng sut Q = 2 3 tn/h
-
9.4. Thit b un nng lm vic p sut chn khng
Trong thit b loi ny c mt b phn ht chn khng nhm hn ch
tn tht sinh ra trong sn phm. Loi thit b ny thng dng trong ch bin
thc phm, dc phm, thc n tr em. Loi thit b ny va c tc dng un
nng, va c tc dng khuy trn
1. Thn thit b hnh tr
-
2. Phng hi
3. Cnh khuy
4. ng c
5. ng dn hi vo
6. ng dn nguyn liu vo
7. ng dn sn phm ra
8. Ca quan st
9. Van tho nc ngng
10. Hp gim tc
11. p k
12. van ht chn khng
9.5. My lnh nhanh
* Dng ng xon rut g
c s dng lm ngui dch ng
Tc nhn lnh l nc mui trong
Thi gian tin hnh lnh nhanh ph thuc vo khi lng dch ng,
nhit ca nc mui lnh. thi gian lm lnh c th kt hp vi vic
x nc lnh t trn xung
-
* Dng khung bn
My ngun c cc tm thp khng g ghp li vi nhau trn mt dn
khung, cc tm ny c l vo v khe h 4 gc dch lng i qua. Cc
giong cao su c cu to c bit trong cc tm i to ra hai phn ring
bit: 1 phn dch ng i qua, 1phn tc nhn lnh i qua ngc
chiu nhau.
My c 2 vng lnh khc nhau
Vng 1: lm lnh trung gian, gim nhit t 5 - 600C
Vng 2: lm lnh nhanh xung nhit yu cu
vng 1: nc dng lm lnh c nhit khong 100C
vng 2: dng tc nhn lnh c nhit thp nh cc dung dch mui
kim tra nhit ca dch ng v tc nhn lnh ngi ta thng
lp ng h o ca vo v ca ra.
C th iu chnh nhit bng tay hay t ng n nhit yu cu.
c im my lnh nhanh:
- dng h nhit nhanh ca loi dung dch nhm trnh nhim
trng v t yu cu cng ngh ch bin
- H nhit nhanh trong thi gian ngn
- B mt truyn nhit ln v theo yu cu cng ngh
- Vt liu ch to t thp khng d, chu mn, chu axit, khng nh
hng ti cht lng sn phm
- Tc nhn lnh l nc mt v nc mui lnh
Ch thch cu to thit b.
1. Ca dch cn lm lnh vo
2. Dch ra
3. Nc mui lnh vo
4. Nc mui ra
5. Nc mt vo
6. Nc mt ra
7. Cc tm tn nhit
-
9.6. Thit b ln men
9.6.1. Qu trnh ln men
Dch ng sau khi lm lnh, lng trong c a vo thng ln men
tin hh ln men chnh v ln men ph
9.6.2. Ln men chnh
Mc ch l c chuyn ng v dextrin c phn t thp thnh
C2H5OH , CO2 v cc sn phm khc, to tthnh bia theo cc yu cu k
thut, cht lngln men ph
Mc ch ca qu trnh ln men ph l tng cng nng C02, hon
thin mi v cho bia.
n nh cht lng bia, thc hin qu trnh chn ca bia a bia v
nht bo qun.
V cu to thit b ln men bia
-
Qu trnh ln men chnh l ln men ph c thc hn trong cng
mt thit b. Loi ph bin l thit b y chp hnh tr.
Kch th khong t 200 - m3
Chiu cao: ng knh thit b - 2 - 5 ln
Vt liu ch to thit b thng bng nhm, inox hoc thp trng men,
thp khng g 17% er, 10% Ni, 2,52% Mo, c thp
Tc nhn lnh c s dng nhm to nhit ph hp cho qu trnh
ln men l nc mui lnh
Bn ngoi thit b ln men c lp bo n nhm n nh nhit trong
sut qu trnh ln men, trnh s nh hng mi trng.
Qu trnh iu chnh nhit (lnh). i vi ln men chm
- Ln men chnh
- Dch ng- mal - houblon nhit 100C c bm vo thng ln
men nhit 80C thi gian t 6 - 10 ngy.
- Ln men ph
Nhit ln men ph t 1 - 40C. Thi gian t 10 - 30 ngy
- Cu to ni ln men v cc van, ng ng phi chu c p sut
m bo cho:
Vic kh trng p sut cao.
p sut d trong qu trnh ln men
-
Chng 10. My v thit b lm lnh.
10.1. Nhng khi nim chung
Trong sn xut TP nhiu qu trnh cn tin hnh nhit thp hn
00C do khng th dng khng kh, nc hay nc lm lnh m cn
tin hnh sn xut lnh.
Nh c sn xut lnh m c th km hlm c s pht trin ca VSV,
ko di c thi gian bo qun, tng tr. Ngoi ra sn xut lnh cng l yu
cu khng th thiu vi mt s ngnh ch bin TP nh sn xut kem, sa
cha, bia
C s l thuyt.
Qu trnh lnh l qu trnh thu nhit t ngun c nhit thp ri
truyn cho vt c nhit cao hn. V vy cn phi tiu tn cng bn ngoi.
thu nhit t ngun c nhit thp truyn cho vt c nhit cao hn
cn vt cht lm tc nhn lnh.
Cc loi my lnh dng hi nn
L loi my c s dng rng rli hin nay, s dng tc nhn lnh l
cht kh khi bc hi cho nhit thp
Chu trnh lm vic ca my lnh l chu trnh cacho ngc.
S nguyn l
-
1-2. Nn on nhit hi tc nhn lnh, nhit hi thay i t to T,
tiu hao cng L1
2-3. Ngng t ng nhit hi tc nhn lnh, nhit lng to ra mi
trng xung quanh (nc hoc khng kh mt nhit lng Q.
3-4. Giln on nhit lng tc nhn lnh, nhit thay i t T To,
sinh cng Lo
4-1. Bay hi lng tc nhn lnh, thu mt lng nhit ca ngun lnh
l Qo
10.2. My lnh nn hi 1 cp
10.2.1. Chu trnh l tng ca my lnh nn hi mt cp
S thit b
My nn ht hi m tc nhn lnh t thit b bay hi c nhit To v
p sut Po. Hi c nn n p sut P v nhit T. Hi tc nhn lnh i
vo thit b ngng t, y hi c ngng t thnh lng.
Sau khi ngng t, tc nhn lnh i vo van tit lu t n p sut Po
v nhit gim n To.
T van tit lu, tc nhn lnh i vo thit b bay hi y tc nhn
lnh thu nhit ca ngi lnh bay hi. Sau thit b bay hi, chu trnh ht
vo my nn li bt u t u.
-
th T - S (nhit - etropi)
1-2. Nn on nhit
2-3. Ngng t ng nhit
3-4. Giln on nhit
4-1. Bay hi ng nhit
10.2.2. My lnh nn 1 cp vi hi kh v bnh tch lng
Trong thc t ngi ta khng tin hnh nn trong vng hi blo ho m
v khi tin hnh trong vng ny s gy va p thu lc cho my nn lm
my d h hng do qu trnh nn trong my s i theo ng (1' - 2')
hoc (1 - 2') n 2''
c c qu trnh nn hi blo ho kh v hi qu nhit th yu cu
sau thit b blo ho phi c mt thit b tch lng. Nu s dng tc nhn
lnh l NH9 s nn theo ng 1' - 2'. Nu l tc nhn lnh freon s nn theo
ng 1 - 1' v 1 - 2'
Nguyn tc lm vic
Hi m t thit b bay hi trc khi vo bnh nn kh phi i qua bnh
tch lng.
Tc dng ca bnh tch lng ny l nh c s thay i v hng dng
v vn tc dng ca lung hi lng trong bnh. Cht lng c tch ra ri
xung y thit b tch lng v vy lung hi i v pha my nn s trng
thi hi blo ho kh.
-
10.2.3. My nn 1 cp vi hi kh c thit b hon nhit
Sau khi ngng t hon ton thit b ngng t, tc nhn lnh c a
qua thit b hon nhit trao i nhit vi hi tc nhn trng thi blo ho
kh (im 1). Sau khi trao i nhit, tc nhn lng trng thi hi cao p
ng vi p sut hi PN v nhit TN lc i vo v i ra nhit T'''. Hi
tc nhn ang Po v To nhit T's, T'' t trng thi T'' tc nhn qua van tit lu, bay hi v thu nhit ca vt cn lm lnh.
-
T thit b hon nhit, hi l hi blo ho kh qu nhit c my nn
ht vo v ra im 2' i vo thit b ngng t v ra trng thi 3, chu trnh
lp li nh c. Hiu sut ca my cao hn khi c thit b hon nhit.
10.2.4. My lnh nn mt cp c thit b lm mt tc nhn lng cao p
sau ngng t
Trong thc t nng cao h s lnh m khng cn thit bh hon
nhit, ngi ta dng mt thit b lm gim nhit ca tc nhn lnh sau
ngng t t TN xung T3'. Thit b lm mt thng dng ng lng ng nhit
T3' thp nht cng ch bng nhit nc lm mt.
10.3. My nn lnh nhiu cp (2 cp)
Khi gim nhit bay hi v tng nhit ngng t, ngha l khi tng
hiu s nhit T - To tng ch s nn th lm gim hiu sut my nn.
My nn lm lnh bng NH3 ch lm vic thch hp vi ch s nn < 8 9
Ngoi ra khi nn n p sut cao s lm tng nhit hi tc nhn
lnh, do nso c th b phn hu, i vi NH3 nhit phn hu l 1200C
V vy khi nn n p sut cao, ngi ta dng my nn 2 bc hay 3
bc. Trong thc t khi nhit bay hi l To = 250C dng my nn 1 bc, khi
To = - 25 - 500C dng my nn 2 bc, khi To = - 50 - 70
0C dng 3 bc.
S
-
1. Thit b bay hi 5. My nn cp cao
2. My nn cp thp 6. Thit b ngng t
3. Thit b lm lnh cp thp 7. Van tit lu
4. Thit b phn ly 8. Van tit lu
Nguyn tc lm vic
Hi tc nhn lnh t thit b bay hi (1), c p sut Po c ht vo xi
lanh cp thp. Hi c nn n p sut P1 sau qua thit b lm lnh (3)
ri i vo thit b phn ly (4). Trong thit b phn ly hi qua cc lp cht
lng c ht vo xi lanh p sut cao (5). y hi c nn n p sut P2
v a vo thit b ngng t (6). Cht lng c to thnh do ngng t hi s
qua van tit lu (7) p sut ca tc nhn lnh gim t P2 xung P1, sau
lng tc nhn lnh c a vo thng phn ly. Phn cht lng tng thng
phn ly s ti van tit lu (8), gim n p ut Po ri cho vo thit b bay hi
(1) nhn nhit t ngun lnh.
10.4. S lm lnh lin hp
p dng khi lm lnh < - 700C
-
Tc nhn lnh l NH3 v - 13 1. My nn NH3 4,6. Van tit lu
2. My nn - 13 5. Thit b ngng t, bc hi 3. Thit b bc hi - 13 7. Thit b ngng t NH3 10.5. My lm lnh kiu hp th
1. Bung lm mt 4. Bm
2. Bnh bc hi 5. Bung lnh
3. Bnh hp th 6, 7. Van tit lu
10.6. Tc nhn lnh
a. Yu cu ca tc nhn lnh
-
- Nhit ti hn phi ln m bo khi ngng t hi tc nhn lnh
c th dng nc hoc khng kh lm mt
- Nhit d bay hi ln, ngha l lng tc nhn lnh dng nh
- Th tch hi ring phn nh kch thc my lnh nh
- p sut bay hi > p sut kh quyn mt t pht hin s r r ca
tc nhn lnh d hn l khng kh thm vo my. Khi khng kh lt vo s
lm tng p sut lm vic, gim h s truyn nhit. Trong khng kh c hi
nc s ng bng thit b bay hi v to thnh cc hp cht ho hc c
hi.
- Khng to thnh hp cht vi du bi my
- Khng chy n, khng c hi, r tin
b. Mt s tc nhn lnh ph bin
* NH3 nhit ng c - 770C
ng dng: My lnh, my nn pittong nng sut ln
u:
- Nhit ti hn ln tth = 132,40C
- Th tch hi nh
- p sut lm vic ngng t khng qu cao 9 - 14 at
- p sut bc hi khng qu thp, d pht hin r r
* CFC (clora flora cacbon)
ng dng l tc nhn lnh ph bin nht
u:
- Khng c hi cho ngi
- Khng gy chy n
Nhc
- Rt nh, tn ti trong kh quyn hng trm nm. Trong thi gian ny
chng tp trung bng bnh lu v phn gii thnh cloine ph hu tng ozon
Mt nguyn t cloine c th ph hu hng nghn phn t ozon
* Hydrocacbon
-
Hin nay hidrocacbon l cht thay th cho CFC lm tc nhn lnh.
Vi t lnh gia nh v my lnh thng mi th 3 tc nhn lnh c quan
tm l:
- Propan nguyn cht R290
- 180 butan c dng cho t lnh gia nh
- Hp cht hidrocacbon dng cho my lnh thng mi
u
- Nhit lng bay hi ln > CFC do nhit lng thu vo khi bay hi
ln
- Khi lng ring < CFC ch bng 40% so vi R - 12
Nhc
- D gy chy n khi c trn ln vi khng kh v mi n
- Khi r r HC n khng phn tn trong khng kh m tch t
- bn di nn cn t cch xa cc in, m t in
Cht ti lnh
Trong my lnh ngi ta thng dng mt cht trung gian mang
nhit t vt cn lm lnh ti tc nhn lnh.
Cht trung gian gi l cht ti lnh
* Freon l cht khng mu, c mi thm nh thng dng l freon 12,
22 l dn xut halogen ca hidrocacbea
u
- Nng hn khng kh, khng c cho ngi, khng n mn kim loi
Nhc
- Nng sut lnh ring thp do lu lng freon tun hon phi ln,
tn tht ma st v tn tht trn cc ng cc b ln, nht l cc van tit lu
- H s truyn nhit K thp hn NH3 nn c cng cng sut phi c
din tch truyn nhit ln hn.
- Kh pht hin r r
- 4000C fron phn hu ra flo v clo gy c hi cho ngi
ng dng: my lnh nn mt cp c thit b hon nhit.
-
Thng l my lnh khong - 30 - 100C
10.7. Cc trang b lnh
1. My nn:
a. L b phn ch yu nht trong h thng lnh
Nhin v: ht v nn tc nhn lnh vi p sut cao phn loi
- Da vo tc dng: my nn tc dng n
my nn tc dng kp
- Da vo cng sut lm vic: lm vic P cao
P va
P thp
- Da vo cu to: my nn piston
Roto
Trc vt
b. Cc b phn chnh ca my nn piston:
* Khung my:
- L gi cho cc b phn khc ca my.
Yu cu phi c bn, vng chc m bo cho cc b phn
lm vic bnh thng
- Khung my thng c bng gang xm ri a i gia cng cn i
vi cc my lnh khc c cng sut nh th c th c bng hp kim Al
gim t trong lng chung ca my
- Khung my c ca c th m ra lp cc b phn vo bn trong,
pha di khung my c th c ca quan st c mc du trong my m
khng cn m np
Khung my cn c thit k khng gian rng trc khuu c th
chuyn ng v cha du bi trn my
* Xi lanh
Cu to c 2 cm van chnh. Yu cu i vi 2 cm van l phi ng
m nhanh v chnh xc
-
Kt cu ca van khng to ra nhng khong khng gian cht trong xi
lanh. C th lp van ht v van y trn cng mt a, a t phatrn
ca thnh xi lanh.
- Khi p sut trong xi lanh > p sut ngng t th van y m, tc nhn
lnh i ra.
- Khi piston chuyn ng ln trn th van ht ng
- Khi piston chuyn ng ln xung di th van m
Nh vy tc nhnlnh c ht v nn, i ra cng mt chiu. Vt liu
ch to van l thp hp kim chu c P, nhit cao, chu c mi
mn.
Xi lanh c ch to t gang xm c cht lng cao
c bit trn piston c t 2 4 xecmng bt kn.
Ngoi ra pha di ca piston ca 2 xecmng du c tc dng xoa du
bi trn ln thnh xi lanh.
Xecmng trn phng v xecmng u c tit din ngang hnh thang.
2. Thit b ngng t
Nhim v: Lm ngui v ho lng tc nhn lnh t my nn ti mi
trng lm lnh c th l nc hay khng kh
Phn loi: Dng ng chm
ng lng ng
ng rut g
a. Kiu ng lng ng
ng nh lng trong ng ln
v c hn hai u
Nu lm mt bng H2O
th H2O v tc nhn lnh
i ngc chiu nhau
i vi thit b ny do c
nhiu on ng khc nhau nn
-
yu cu cc mi hn phi tht kn
H s truyn nhit 930w/m2
Nhc: Nu nng sut ln th tn nguyn vt liu
b. Thit b ngng t kiu ng chm nm ngang
c s dng rng rli ph bin nht trong cc h thng lnh i vi
cc loi my lnh c cng sut ln va khong t 12 kw - 3500 kw v c
dng cc ni c ngun nc di do u:
Kt hp hi ho vi cc h thng my lnh sao cho tin ch hp l v
hiu qu lm v sinh thun li d dng.
Kt cu theo kiu ng chm nm ngang, 2 u c np.
Thng thng ng knh ca thit b D khong t 0,5 m 1m c
chiu di l khong t 3,6 6,1m
S ng ~ 300 ng, ng knh ng ~ 50 mm
c b tr ng thu quan st mc cht lng tng ng chm. Nu
mc cht lng qu ln s hn ch mc cht lng trao i nhit, lm h s
trao i niht gim H2O trong ng phi c tc n nh. C th dng
bm tng cng chuyn ng ca dng nc lm tng qu trnh trao
i nhit.
c. Thit b ng chm theo kiu thng ng
C cu to thn hnh tr NH3 vo trn, ra di
Trn thit b c van an ton, ca x kh khng ngng tng t nh
thit b kiu nm ngang. H2O i khng gian trong ng. Tc nhn lnh i
-
khong khng gian ngoi ng. nc chy thnh dng xoy trong ng ta
dng h thng phn phi nc pha trn.
ng knh thit b khong 0,6 1,2m
H s truyn nhit K
d. Thit b ngng t kiu xi nc
Cu to n gin nhng cng knh
e. Thit b ngng t dng nc kt hp vi khng kh.
Dng nhng ni c ngun nc khng nhiu.
Hi tc nhn i vo pha trong gin ng. Sau khi nhn nhit ca trc
t trn xi xung v i ra pha di. Khng kh pha di ln nhn nhit
v truyn nhit, bay hi ko theo mt lng nc. H s truyn nhit k t
450 600w/m2 , nh thit b gn nh, c th t trong nh
3. Thit b bay hi
L thit b i nhit b mt, nhim v thc hin qu trnh bay hi ca
tc nhn lnh c nhit < nhit ca vt cn lm lnh phn loi.
Thit b bay hi dng lm lnh
Cht lng
Cht rn
Khng kh
a. Thit b bay hi dng lm lnh cht lng
Thit b bay hi kiu ng chm, l thit b c dng nhiu nht.
Cu to v nguyn l lm vic ging nh thit b ngng t ng chm.
Ch khc l i vi thit b bay hi ca ra t pha trn. Nc mui chuyn
ng trong ng nh. Tc nhn lnh c a vo di y thit b v c
si bn ngoi ng truyn nhit nhit thp.
Thit b bay hi phi c bc mt lp cch nhit trnh tn tht
nhit nc mui sau khi c lm lnh.
Thit b bay hi dng ng chm nn t nm ngang
u: Thit b gn nh, vn hnh thun tin, h s truyn nhit tng
i ln. kn tt hn ch tc n mn ca nc mui.
-
Nhc: hay xy ra hin tng ng c, ng bng
b. Thit b bay hi loi gin ng thng ng
c dng trong sn xut cy
Cu to v nguyn l lm vic ng knh D 121 123mm. Trong
khong 31 38mm, gm 2 ng gp trn v di. lm gim h s ttruyn
nhit ngi ta khng lm ng thng m lm gin ng an cho nhau.
B bn ngoi l khung chu lc. Gin bay hi c t st thnh b c
dng cnh khuy y dung dch nc mui qua gin. Dung dch mui sau
khi c lm lnh s c y qua cc thnh ca khun . Gin bc hi tc
nhn lnh c a vo pha trn sau c phn b u vo cc ng
ngoi.
Trong thc t c th dng thit b bay hi dng tm bn v dng l xo
c. Thit b bay hi lm lnh khng kh
L dng thit b trao i nhit, cht lng i trong ng, khng kh bc
ngoi ng. Thit b c th l gin ng trn c th l gin ng c gn.
Dng ng c th l dng ng xon hoc ng gp
Khng kh bc ngoi ng c th l i lu t nhin hoc i lu
cng bc.
Thit b bay hi lm lnh khng kh i lu t nhin l mt gin ng
thng c un xon khng c mi hn.
Thit b bay hi dng ng gp. Tc nhn lng i vo pha di v
c dn u cc ng
-
4. Cc thit b ph trong my nn
a. Thit b tch lng
Bo m cho h thng hot ng vi hnh trnh kh (tch cht lng ra
khi hi trnh cc va p thu lc gy h hng my).
b. Thit b tch du: Ch c trong my nn hi dng NH3 hi.
Sau khi ra khi my nn c mang theo 1 lng u bi trn.
c. Bnh cha cao p
L mt bnh hnh tr, t nm ngang, dng cha tc nhn lng sau
thit b ngng t
d. Bnh thu hi
L bnh hnh tr t nm ngang, dng cha tc nhn lng t thit b
bay hi. Trong trng hp cn sa cha hay ph bng ngi ta a v hnh
ny.
e. Bnh trong khng gian
Bnh c lp gia my nn cao p v my nn thp p Nv ca bnh
duy tr p sut trong khng gian v a hi n trng thi bo ho khng
phn phi cho cc tc nhn lng & cc thit b bay hi chung v thp p
-
Chng 11. Thit b c c
11.1. Khi nim chung
C c l qu trnh ch bin nhit, nhm mc ch:
- Gim in nc trong sn phm
- Tng gi tr dinh dng v gi tr s dng cho sn phm
- Gim khi lng thun tin cho vic vn chuyn, ch bin v bo
qun sn phm
Tuy nhin trong qu trnh c c di tc dng ca nhit cng gy
nhng bin i cho sn phm: cht lng, mu sc, mi v
C c khc vi bay hi
- C c xy ra trong ton b khi cht lng, nhit si
- Bay hi sy ra trn b mt ca khi cht lng v bt k nhit
no (nhit si)
Phn loi cc thit b c c: * un si d2 dng hi t hi do d2 bay
ln - hi th
- Da vo hnh thc lm vic: lin tc 2 gin on
- Da vo p xut: P cao & P thng, p chn khng
- Da vo cu to: ng chm, 2 v, ng rut g
11.2. Thit b c c chn khng
11.2.1. Thit b lm vic p xut chn khng ( mt ni)
Cng dng: dng c c nhng sn phm cn gi c mu sc,
hng vi, vitami. Qu trnh c c c thc hin p xut < p xut
thng, nhit si ca sn phm
-
1- Bung bc hi vi c c
2- Bung t ni c c
3- Thit b ngng t
-
4- Thit b to chn khng
5- Bm chn khng
6- B nc trn
7- B nc di
V cu to, thit b c c c th l hnh tr hay hnh cu. Gm 2
phn:
Phn di: bung t (b mt truyn nhit)
Phn trn: bung bc hi, hi th c tch ra khi h2 lng, hi ca
dung dch si
* un si dung dch, ngi ta c th dng bt c cht ti nhit no,
nhng thng thng ngi ta dng hi t, hay cn gi l hi nc, hi s
cp.
Hi do dung dch si bay hi ra gi l hi th.
qu trnh truyn nhit t, phi b tr cc ng ng hi hp l,
thun li cho qu trnh tho nc ngng. Ngoi ra trong ng nhit phi c
van x kh khng ngng.
Nguyn l lm vic
M bm chn khng, ng thi m van nc cho nc i vo thit b
ngng t to ra chn khng cho thit b c c cho nguyn liu vo thit
b c c.
M van hi cho khi nng vo bung t un nng nguyn liu
n nhit si, nc s bc hi ra khi khi nguyn liu
Khi qua trnh c c t yu cu cng ngh, ng van cp hi, ngng
bm chn khng cho n khi ni c c t p xut thng mi m van tho
nguyn liu ra.
11.2.2. Thit b c c nhiu ni lm vic P chn khng.
Do c im ca thit b c c 1 ni l hi th sau khi ra khi thit
b c c chuyn sang thit b ngng t s c ngng t li thnh cht lng
chy ra ngoi.
- Khng tn dng c hi th
-
tit kim hi th, ngi ta thit k h thng c c nhiu ni: dng
hi th ca ni trc lm hi t cho ni sau. Ni c c u tin c t0 si
cao nht, nhng ni sau c t0 si gim dn.
H thng c c 3 ni.
Ni 1: Hi un nng c a vo b phn truyn nht un si
nguyn liu.
Hi th ni 1 a sang un nng ni 2
Sn phm t ni 1 c dn sang ni 2
Hi th ni 2 a sang ni 3
Hi th ni 3 a sang thin b ngng t
Nh vy hi s cp ch a vo ni u tin, do so vi c c 1 ni
th lng hi t tiu hoa trn 1 t sn phm nh hn
- Ni 1 tho nc ngng bnh thng, ni 2,3 phi dng thit b c
bit tho nc ngng
- p sut hi th gim dn t ni 1 - ni 3, do t0 si ca cc ni
theo. Chn lch t0 ny 2 - 50C
- Nguyn liu t chy t ni 1 - ni 2 - ni 3 do s chnh lch p
sut. ni 3 mun tho sn phm ra phi s dng bm ht
- Hm lng cht kh i t ni 1- ni 3 tng dn
- Nng sut ca h thng c c nhiu ni ph thuc vo s lng ni.
S lng ni cng ln th nng sut cng cao nhng khng th tng s lng
ni n v hn do phi m bo chnh lch p sut cc ni.
Nhc im:
H thng c c si nhiu c t0 ca dung dch ni sau (ni trc
nhng nng d2 ca ni sau) ni trc lm cho nht d2 tng nhanh - h
s truyn nhit gim t ni u n u cui
* khc phc hin tng ny ngi ta ra h thng c c ngc
chiu. Hi di chuyn ging nh trng hp xui chiu, cn dung dch u i
vo ni 3. Sn phm ra ni 1 y do p sut ni trc, ni sau nn dung
dch khng t chy t ni n sang ni kia m phi dung hi vn chuyn.
-
u im: ( h thng ngc chiu) nhc im
- H s truyn nhit n nh Tm bm
- Tn t nc ngng t hi
* Ngoi ra cn c th mc h thng c c theo kiu song song khi
yu cu nng ca d2 khng cao lm, hoc d2 c kt tinh vi khi kt tinh d
gy tc ng.
Dung dch u vo ng thi 3 ni. Sn phm ng thi ly ra c 3
ni
-
11.3. Thit b c c 1 ni L/vic P thng
Cu to
1- Thn ni
2- ng nhit (dng ng xoc rut gi)
3- Bung bc hi
4- B phn cp nguyn liu
5- Van tho nc ngng
6- Ca y tho sn phm
7- ng hi nng vo
8- ng nguyn liu vo
9- Ca thot m (hi nc)
10- Ca quan st
11- Ca thot kh khng ngng
12- ng nc lnh vo
Nguyn l lm vic
- Kim tra an ton thit b, ng cc c cc van, m van x kh v
van tho nc ngng.
- Cho nguyn liu l un nng s b 85 950C vo thit b.
Nguyn liu phi ngp ng truyn nhit t 10 20cm. ng van cp
nguyn liu, m van hi 1 cch t t trong 3 5s ri m to bnh thng.
- Khi khng kh trong ng truyn nhit l b ui ht ra ng
van x kh, m van tho nc ngng.
- Hi nc i qua ca thot m ri c ngng t ngoi thit b.
Khi lng dung dch gim dn, gim n u b sung dung dch vo
n sao cho mc dung dch trong thit b l khng i.
- Qu trnh lm vic phi lun gi P hi n nh v ph hp vi
tng loi dung dch cn c c.
-
- Lu nguyn liu phi ngp ng truyn nhit, trnh hin tng
chy trn b mt ng truyn nhit.
- Khi sn phm t yu cu, kt thc c c, ng van cp hi m
van nc lnh cho hcy vo ng truyn nhit trnh hin tng chy
trn b mt ng truyn nhit.
- M van tho sn phm, vn sinh thit b.
-
Chng 12. thit b chng ct v tinh ch
12.1. Khi nim c bn
* Quy trnh cng ngh sn xut ru etylic c th chia thnh cc
cng on chnh gm:
- Chun bn dch ng ln men
- Gy men ging
- Ln men dch ng
- X l dch ln men
Thit b chng ct v tinh ch l thit b s dng trong giai on
x l dch ln men.
* Chng ct: l qu trnh tch ru v cc tp cht d bay hi
khi gim chn. Kt qu ta nhn c ru th hoc cn th.
+ Tinh ch: hay tinh luyn l qu trnh tch cc tp cht khi cn
th v nng cao nng cn. Sn phm thu c l cn tinh ch hay
cn thc phm c nng trong khong 95,5 96,5%V
+ C s l thuyt ca vic chng ct v tinh ch cn etylic da
trn quan h gia thnh phm pha lng v pha hi v nhit si.
+ Chng khc c c ch: trong qu trnh chng tt c cc cu
t u bay hi, vi c c ch c dung mi bay hi cn cht tan khng
bay hi.
+ Khi chng ct p sut thng 700mmHg, ru - nc to
thnh hn hp ng ph ti thnh phn ru trong pha hi v pha
lng bng nhau. Hn hp ny c nhit bng 78,150C.
Nng ru 95,57% khi lng
97,2% th tch
89,41% phn t
Nh vy khi chng ct v tinh luyn p sut kh quyn ta ch c
th nhn c nng cn nh hn nng trn.
-
* Theo quan im tinh ch cn, ngi ta chia thnh:
Tp cht u
Tp cht trung gian
Tp cht cui
- Tp cht u: cc cht d bay hi alcol etylic cc cht ny c
t0 s alcol etylic
VD: alheclt, axetic, axetat, etyl, axetat, metyl (C2H4O, C4 H8 O2
- Tp cht cui gm cc alool cao phn t C3 H6 O2 ) t0 ) t0 alcol
etylic
- Tp cht chung gian c 2 tnh cht, va c th l tp cht u
va c th l tp cht cui. lng alcol thp, chng ch thnh tp
cht u. VD: isobutyrat etyl, isovlert, etyl} este C6 H12 O2 C7 H14 O2
iu khin qu trnh chng ct, tinh luyn ngi ta da vo yu t
P, t0, nng
12.2. S thit b chng ct v tin ch
12.2.1. Thit b chng luyn cn th gin on
Thit b chng gin on
-
1. Thng cha dm
2. Thn thp
3. Bnh ngng t v lm lnh cn
Dm chn oc bm vo thng chng ct, sau m hi em cho
si. Hi bay ln chiu cao thp 2 c nng cao nng , ra khi thp
vo thit b ngng t v lm lnh 3 ri i vo thng cha.
u im:
- n gin, d thao tc
Nhc im:
- Do mt t 6 -8 h nn thng cha ln - tn vt liu ch to nng
sut thp.
- Dm chn khng c un nng bng nhit ngng t ca cn
th nn tn hi
- Nng cn khng n nh v gim dn theo thi gian lc u
t 75 - 80% V n cui t 5 - 6% V. Nng trung bnh t 20 -
30% V.
- Tn tht ru gp 3 - 4 ln chng lin tc
Thit b chng lin tc
-
1- Thn thp th
2- Bnh hm dm v ngng t cn
3- Bnh ngng t va lm lnh
Tinh ch cn
loi tp cht trong cn th, ngi ta s dng NaoH, kmno4
RCOOC2H5 + NaoH RCooNa + C2 H5OH
R1COOH + NaoH R1CooNa + H2O
2 KMnO4 + 3 CH3CHO+ NAOH 2 CH3COOK + 2MnO2 +
2H2OCH3COONa
Tinh ch cn gin on
Cho cn th va x l vo thng 1, dng hi trc tip v gin tip un
n 80 900C
- ng van hi, cho phn ng 1 2 gi, ng thi m nh nc
ngng t phn hi ru bay ln.
- M van hi gin tip un ti si, ng thi m nc ngng ton
b hi ru i vo 3, phn kh khng ngng qua 4 ra ngoi (nu c ru cn
thu li)
- Sau 30 60' si v hi lu, cc tp cht bay hi c y ln nh
thp.
iu chnh hi v nc lm lnh ly ra 3 5% cn u 6 12% cn
2a.
iu chnh hi lu ly ra cn sn phm chnh III
Lng ny ~ 60 80%
Cn 2b 6 12%
Du fusel 3 5% (du kht, alol cao phn t)
Cso th ly du pusel theo tng m hoc 2 3 m ly 1 ln
-
Thit b chng ct v tinh luyn bn lin tc
(Chng gin on, luyn lin tc)
Sau khi ln men xong, dm chn c bm vo thng cha 1. V lm
vic gin on nn b tr hai thng song song nhng lm vic so le n
nh phn no nng cn th trc khi vo thp tinh.
Thng ct th c un trc tip bng hi c p sut 0,8 1kg/cm2.
Hi ru bay ln c ngng t 2 ri vo thng cha 3, tip lin tc
i vo thp tinh ch 4 thit b 4, un nng bng hi trc tip, t a tip
liu (a 16 18 tnh t di ln) n pha y thp th nng cn gim
dn n 0,015 0,03% ri ra ngoi. Nhit dy thp ~ 103 1050C. Hi
ru bay ln c tng dn nng , phn ln c ngng t 5, ri hi lu
tr li thp. Mt phn nh cha kp ngng cn cha nhiu tp cht u c
a sang ngng t tip 6 v ly ra dng cn u. Cn u ch dng
pha vecni, lm cn t st trng hoc em x l v ct li.
Cn sn phm ly ra dng lng cch a hi lu t trn xung)
khong 3 6 a, lm lnh 7 ri cha vo thng. Cn ly ra nh vy c
nng thp hn so vi cn ly nh khong 0,3 0,5V nhng cha t este
-
v andehit hn. Cht lng cn tu thuc vo chiu cao thp v cch vn
hnh song v nguyn tc u tho mln TCVN - 1971.
S chng luyn bn lin tc
1. Thng ct th 5. Bnh ngng t
2. Thng ngng t cn th 6. Bnh ngng t
3. Thng tm cha cn th 7. Bnh lm lnh
4. Thp tinh ch 8. Bnh lm lnh
Thit b chng ct v tinh luyn lin tc
Loi 2 thp
Dm chn c bm ln thng cao v 1, sau i vo bnh hm dm
2. y dm chn c hm nng ti 70 800C bng n nhit ca hi cn
th, sau qua bnh tch CO2 3 ri i vo thp 4. Hi cn bay ln ngng t
-
2, phn cha ngng tip tc sang ngng 6. Ton b cn th ngng 2, 6,
7 i vo thp tinh ch 8 a16 18 t di tnh ln. Thp tinh ch c cp
nhit bng hi nc c p sut 0,8 1kg/cm2. Hi ru bay ln c nng
cao dn nng cn ra khi thp i vo thit b 9. Ti y ta iu chnh
lng nc lm lnh ly cn u ra thit b 7, khong 3 5% so vi
ton b lng cn a vo thp. Lng cn ngng thit b 9 c hi lu
tr li thp.
Cn thnh phm c ly ra dng lng cch a hi lu 3 6 a,
ri c lm lnh thit b 10.
Nhit y ca 2 thp lun bo m 103 1050C.
Nhit nh thp 4 ph thuc nng cn trong dm v thng vo
khong 93 970C. Nhit nh thp tinh luyn v tr cch a tip liu v
pha trn 3 4 a c khng ch 82 830C.
Du fusel ly ra dng hi t a 6 11 (tnh t di ln) c ngng
v lm lnh thit b 11.