Removal of Insolubles(Filtration)
Filtrationremoval of solid particles from a fluid by passing the fluid through a filtering medium or septum, on which
the solids are deposited
• Air Filter• Liquid Filter (water purifier)
MicroorganismInsoluble fermentation broth
Soluble brothvs
Equipment
Laboratory Scale
vacuum
Filter paper
Large Scale
Plate and Frame Horizontal Plate
Vertical Leaf Candle Type
Equipment
Continuous Rotary Vacuum Filter
Microfiltration(membrane separation)
Continuous Rotary Vacuum Filter
Filter Press (Pressure Filter)
40 ~ 150 lb/in2
ΔP
Canvas
Feed
Frame FramePlatePlateCanvas Canvas Canvas
Liquid(filtrate)
Wet Cake
Filter Press Operation
i. Feed inputii. Filtrate flow stops or sudden
increase in filtration pressureiii. Wash liquid inputiv. Air blowing (steam blowing)v. Open press and scraping off of
solids
Automation Materials(SUS, PP--)
Operating Variables
• vacuum• wash/spray water
Darcy’s Law
l
Pk
flow rate through a porous bed
where: ν – velocity of the liquidk – constant (Darcy’s law permeability of the bed)ΔP – pressure drop across the bed of thickness lμ – viscosity of the liquid
Holds only when:Reynold No
51
d
where: d – particle size or pore diameterρ – liquid densityε – void fraction in the cake
[1]
[2]
Filtration: Theory
For batch filtration
dt
dV
A
1 where: V – total volume of filtrate
A – filter area
CM RRk
l where: RM – resistance of the filter medium
RC – resistance of the accumulated mass
CM RR
P
dt
dV
A
1
[3]
[4]
[5]
Incompressible Cakes
areafilter
volumefiltratethicknesscake
Therefore, cake resistance RC
A
VRC 0
where: α – specific cake resistanceρ0 – mass of cake solids per volume of filtrateΑ : dimension – length/mass
[6]
Substitution of Eq. 6 into Eq. 5
MRAV
P
dt
dV
A
0
1
[7]
Initial condition 00 Vt [8]
Integration of Eq. 7 yields
BA
VK
P
R
A
V
PV
At M
20 [9]
A plot of (At/V) vs (V/A) should be linear. The slope K is a function of ΔP and of the cake properties.
If medium resistance RM is insignificant, then
2
0
2
A
V
Pt
[10]
Compressible Cakes
SP ' Assume!
Figure 1. Cake resistance versus pressure drop.
Example 2.3-1) Streptomyces Filtration from an Erythromycine Broth
Filtration time(sec)
Volume of fil-trate(L)
5 0.040
10 0.055
20 0.080
30 0.095
Q. Determine specific cake resistance α, medium resistance RM.
A=0.1 ft2
μ=1.1 cP∆P=20 in. of mercuryρ=0.015kg dry cake/L
sol.) Darcy’s law:
in. in.∴α=2.4 X 1011 cm/ g
∴RM=0
(V/A) vs. (At/V) plot → y-intercept= 0
Example 2.3-2) Filtration of Beer Containing Protease
Q.1 How long will it take to filter beer at 50 psi? 2 How long will it take at half this pressure drop?
Filtering 3000 L with 15 frames(each of area 3520 cm2)RM is negligible.Total pressure drop(∆P)= 65 psi
* Compressible cake* With funnel 5 cm,filtering 100 cm3 of beer in 24 min* s=2/3
& ∵ compressible cake
0
∴
psi
min psi1/3 /cm3
( R∵ M is negligible.)
psi1/3
Q.1 How long will it take to filter beer at 50 psi?
psi
Q.2 How long will it take at half this pressure drop?
psi
∆P= 25 psi
Example 2.3-3) Filtration of Incompressible Steroid Crystals
Weight of crystals 62 g
Pressure of filtration 15 psi
Filter diameter 5.08 cm
Cake depth 12.5 cm
Cake volume 253.3 cm3
Filtration time 163 min
*Assumption: - Cake is incompressible. - Feed pump: 10 psi - filtrate is raised against the equivalent of 15 ft head.
Q.1 Predict the number of frames needed. 2 Estimate time required to filter a 63 kg batch of steroid.
inin
Q.1 Predict the number of frames needed.
The number of frames needed is 18 frames.
Q.2 Estimate time required to filter a 63 kg batch of steroid.
psi
psi
psi
psi
psi
psi
in2
Purification of the IgG antibody by affinity cross-flow filtration
2011. 10. 5.Danim Yun
24
IgG & cross-flow filtration
Antibodies are proteins made by the immune system to destroy foreign invaders. There are five major types of antibodies: immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin E (IgE) and immunglobulin D (IgD). An IgG antibody helps to battle bacterial and viral infections.
Protein A
IgG
25
Crystalline bacterial cell surface layers (S-layers)
Identical subunits and functional groups show same position and orientation on each S-layer subunit
-> crystalline matrix has a nanometer range.-> using for immobilization of Protein A
Steep rejection curves cut-off; 45,000
After crosslinking the S-layer protein with glutaraldehyde, carboxyl groups from acidic amino acids were activated with carbodiimide and used for immobilization of Protein A
26
cross-flow filtration system
27
Results from affinity cross-flow filtration experiments
Albumin and minor amounts of nonadsorbed IgG
IgG-human albumin mixture
Eluted IgG fraction
28
Thank you
Top Related