4
Vac-u-Fill Bottles
VacuCap fastFiltration(PALL)
FastCap(Nalgene)
Liquid Dispensers
Syringe Pump
Hand Vacuum
Pump
Selection of Filter Media :
by size
Flow propl to (Diam) sqrd
0.45um : 0.22um
1.00 : 0.25 x speed
Syringe Filter : max
Pressure 72psi (PP
body )
on top of main fil-
ter
Pre Filter : protects main
filter from blocking extends
lifetime and can improve
speed
use coarser Glass Fibre
some have Class Fibre
Multi-Layer
on top of main fil-
ter
Relative speed based on
Surface Area of Pore Size
um
13 : 25 : 33mm
0.27 : 1.0 : 1.75 x speed
Measured
Syringe Pump : Olive Oil 25C
30psi (PressGauge)
20ml 19mmID Syringe 0.5sqin >
1.0ml/min
0.45um PVDF
50ml syringe 29mmID
> 2.3ml/min
Vacuum vs Pressure
0.45um PVDF
HandPump Vacuum 350mm = -
7.0psi max developed Vac Flask Fil-
tration
Syringe Filter 25mmD
Thumb Force ~10lb max
= 20psi ( but RSI problems ???)
47mm
25mm
47mm MF Calcu-
lated
Flow=0,66ml/min
x
{ 47/25 }sqd = x
3.5
-= 2.30ml/min
Measured
20ml/6.0min =
3.3ml/min
Olive Oil
Viscosity
43cps 37C
24cps 54C
Flow is propl to 1/ vis-
cosity
heating speeds up
flow
ALL filters tend to block up depending on particulates that actually tend to fill the filter pores
- use of coarser pre-filter (glass Fibre) helps speed and the total sample throughput
for best results - match the polarity of the Membrane material with the polarity of the liquid
hydrophillic : PES > Nylon > PVDF > PTFE Hydrophobic
water-based polar solvents polyester Oils Hydrocarbon-based Oils
these are but generalisations - & it’s very much “trial and error” for each application
Filtration
Accessories
:
Filtration
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