7/24/2019 Bi gng cng ngh mng
1/13
KThut Mng vng Dng
Bi 4: M hnh ha qu trnh chuyn khitrn mng
Ging vin: Nguyn Minh Tn
Bmn QT-TB CN Ha hc & Thc phm
Trngi hc Bch khoa H [email protected]
Vn chuyn vt cht trn bmt mng
Cc hiung gimng lc qu trnhTrlc cp khi cc b
Dung dch vo Nc trong
Phn cc nngpha dungdch vo
Lp
hot
ng
Lp
rng
Phn ccnngphanc trong
-Phn cc nngtrong lpbin pha dch vo(v phn ccnhittrong qu trnh thm bcv thm kh)
- Phn bnngtrong lp dcamngo pha/mng Composit
-Tn tht p sut ca dng thm
qua lp- Phn cc nngtrong lp binca pha nc trong
7/24/2019 Bi gng cng ngh mng
2/13
Vn chuyn vt cht trn bmt mngCc hiung gimng lc qu trnh
Phn cc nngtrong lp bin pha dch vo
Dng (khuych tn, i lu, chnh) trong lp bin pha dch vo
Phn cc nngpha dch vo
Mng
Vn chuyn vt cht trn bmt mng
Cc hiung gimng lc qu trnhPhn cc nngtrong lp bin pha dch vo
(1) Qu trnh chuyn cht phthuc vo mng
- Xy ra trong cc qu trnh phn tch cc cht lng tan ln tun theo nguyn lHatan Khuych tn
- Dng nc lc nh
- Trlc ca mngng vai tr quan trng
- Dng nc lc chunh hng ca hin tng phn cc nng
(2) Qu trnh chuyn cht phthuc lp cn- Xy ra trong qu trnh Siu lc (UF) v Vi lc (MF)- Dng nc lc ln hn- Hskhuych tn ca cc phn tbmng gili nhhn- Cc cu tbgili trn mng lin kt vi nhau to thnh lp
cn/cake layer- Trlc ca mng nhhn trlc ca lp cn
7/24/2019 Bi gng cng ngh mng
3/13
Vn chuyn vt cht trn bmt mng
Cc hiung gimng lc qu trnh
Phn cc nngtrong lp bin pha dch vo(1) Qu trnh chuyn cht phthuc vo mng
Gii thittnh ton nngca cc cu ttrn bmt mng:- Qu trnht cn bng- Qu tnh khuych tn tun theonh lut Fick- Khng xy ra bini ha hc- Gradient nngtheo hng song song vi mng nhhn
Gradient nngvung gc vi mng
Cn bng vt liui vi cu tj bn pha dch vo:
( )
= y
w
Dymwy
j
ijFyGesj &0
Dngi luDng khuych tn
Vn chuyn vt cht trn bmt mng
Cc hiung gimng lc qu trnh
constmym PGes == && )( constmym PijGesij == ,, )( &&
Phn cc nngtrong lp bin pha dch vo
Tch phn phng trnh cn bng vt liu trn kt hp vi:
hay
Cng viiu kin bin:
2:0 jj wwy ==
1: jjF wwy ==
Phn bnng khong khng gian bn trn mng:
=
=
F
y ijF
P
jj
jj
D
dym
ww
ww
0
*
2
*
1exp &
i vi mng loing (htatr)
=
i
Fi
R
R ijF
MP
jj
jj
Dr
drRm
ww
ww
&exp*
2
*1
Nngkhi lng cutj trong dng lc ti v
trang kho st
Dng lc
7/24/2019 Bi gng cng ngh mng
4/13
Vn chuyn vt cht trn bmt mng
Cc hiung gimng lc qu trnhPhn cc nngtrong lp bin pha dch vo
Kt qutch phn l phng trnh m tphn cc nngtrong lp bin pha dch vo
=
=
FF
P
ijF
FP
jj
jj
k
m
D
m
ww
ww
&&expexp
*
2
*
1
i vi mng loing (htatr)
ijF
MP
D
Rm
Fi
ij
Fi
i
ijF
MP
jj
jj
kR
D
R
R
D
Rm
ww
ww
=
=
&
&1lnexp
*
2
*
1
Hscp khi1/kF
Vn chuyn vt cht trn bmt mng
Cc hiung gimng lc qu trnh
ijF
hydP
D
dmPe
=
&
Phn cc nngpha dung dchu vo ca mt skiu mun mng
Phn cc nngpha dch vo trong cc loi mun mng khc nhau
Chun sPecle
=
=
Sh
Pe
dk
PeD
ww
ww
hydF
ij
jj
jjexpexp
*
2
*
1
7/24/2019 Bi gng cng ngh mng
5/13
Vn chuyn vt cht trn bmt mngTrlc cp khi trong lp phtr
Tng quan gia cc dng dc theo chiu di mun z
di tngi
Dch vo
Dng nc lccc b
Dch nc lcchung
(1) Phn cc nng
Vn chuyn vt cht trn bmt mng
Trlc cp khi trong lp phtr
Phn bnngtrong lpkhi dng mng bti xng
Lp
-
7/24/2019 Bi gng cng ngh mng
6/13
Vn chuyn vt cht trn bmt mngTrlc cp khi trong lp phtr
Phn cc nngtrong lptrong cc qu trnh khc nhau
Nc trong
p sut pha nc trong
Khi lng ring nc trong
Hskhuych tn
rng lp
Bdy lp
Phn cc nng
Vn chuyn vt cht trn bmt mng
(2) Tn tht p sutTrlc cp khi trong lp phtr
Tn tht p sut trong lp
p sut trong thit bngng t
p
sutsaulphotng
Dng lc
Isopropanol- nc
7/24/2019 Bi gng cng ngh mng
7/13
Vn chuyn vt cht trn bmt mngDng pha trn hng trc /axial back mixing
Dng pha trn hng trc
c hiu l tt cc cc dngvn chuyn khng ngoi dngi lu
Phn bcc xung chuynng
Thiim pht sinh xung Thiimo
Xung chun khit=0
Xung bi suy gim do cc dng pha trn hng trc:phn bvn tc, dng xoy, khuych tn phn t,
Phn b i xng ti mithiim
Vn chuyn vt cht trn bmt mng
Cc loi trlc v hiung thyng lc tcng ti qu trnh tiu ha cc mun mng
- Cn bng vt cht trong khng gian trc mng v sau mng
- Tn tht p sut trong khng gian sau mng
- Phn cc nngphia dch vo
- c tnh ca mng
- c tnh dng nc trong cc b
7/24/2019 Bi gng cng ngh mng
8/13
Vn chuyn vt cht trn bmt mngPhng php tnh ton cng sut lc cc bca mng
Hphng trnh tnh ton cng sut lc ca mng (trng hp tun theo m
hnh Ha tan Khuch tn)Phn cc nngpha dch vo
Trlc ca mng
Thm thu ngc(RO)
Thm bc (PV)
Trlc ca lp
Phn cc nngpha nc trong
Vn chuyn vt cht trn bmt mng
Phng php tnh ton cng sut cc bca mng
Thm thu ngc: Hphng trnh tnh ton c kdn phn cc nngpha dchvo v trlc ca mng
Sh= f( Re, Sh, kch thc hnh hc)
7/24/2019 Bi gng cng ngh mng
9/13
Vn chuyn vt cht trn bmt mngPhng php tnh ton cng sut cc bca mng
Phn cc nngtrong qu trnh thm thu ngc
Vn chuyn vt cht trn bmt mng
Phng php tnh ton cng sut cc bca mng
nh hng ca phn cc nngpha dchc ti dng qua mng trong cc trnghp khc nhau
Qu trnh mng
Hcht
Mng
Mun Loi ti Loi bn Loing
7/24/2019 Bi gng cng ngh mng
10/13
Vn chuyn vt cht trn bmt mngnh hng ca vtr lp hotng ca mng
Dung dch vo Nc trong
Phn cc nngpha dungdch vo
Lp
rng
Phn ccnngphanc trong
Lp hot
ng
Vn chuyn vt cht trn bmt mng
nh hng ca vtr lp hotng ca mng
Hphng trnh tnh ton cng sut lc ca mng khi lp dtip xc vi dch votrong qu trnh RO
7/24/2019 Bi gng cng ngh mng
11/13
Vn chuyn vt cht trn bmt mngnh hng ca vtr lp hotng ca mng
Hphng trnh tnh ton cng sut lc ca mng khi lp dtip xc vi dch vo
trong qu trnh PV
Vn chuyn vt cht trn bmt mng
nh hng ca vtr lp hotng ca mngHphng trnh tnh cthcho qu trnh RO v GP
7/24/2019 Bi gng cng ngh mng
12/13
Vn chuyn vt cht trn bmt mng
Cc phng php tng cng qu trnh cp khi trnmng
- To ra dng nhiu pha
- Thm cc ccu to xoy trong khng gian dch vo: Feed-Spacer
- To mng rung khi lm vic
- a dchc vo mun di dng xung
Vn chuyn vt cht trn bmt mng
Cc phng php tng cng qu trnh cp khi trnmng
S nguyn l pp to dnga pha
7/24/2019 Bi gng cng ngh mng
13/13
Vn chuyn vt cht trn bmt mng
Dng Feed Spacer
S nguyn l pp dng Feed Spacer