more Filtration Hints 2016
|
Filtration Accessories Filtration Hints
|
Vac-u-Fill Bottles PDF VacuCap fast Filtration(PALL) FastCap(Nalgene)
|
Liquid Dispensers DoibleCheckValve Dispenser Syringe Syringe Pump
|
Hand Vacuum Pump
|
Selection of Filter Media : by size >Flow proportional to (Diam) sqrd
|
0.45um : 0.22um 1.00 : 0.25 x speed
|
Syringe Filter : max Pressure 72psi (PP body )
|
Membrane Filter
|
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 filter
|
Relative speed based on - Surface Area of Pore Size um
|
13 : 25 : 33mm;(50mm 90mm 0.27:1.0:1.75:4.0, 1.3 x speed
|
at same Pore Size um & samemembrane material
|
|
- Liquid Temperature
|
eg ambient +20degC
|
~2x the speed 1/2 the viscosity
|
DON”T exceed membrane or filter holder max use Temp - generally 65degC MAX > BUT CHECK !
|
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 Filtration Syringe Filter 25mmD Thumb Force ~10lb max = 20psi ( but RSI problems ???)
|
47mm
25mm
|
47mm MF Calculated Flow=0,66ml/min x { 47/25 }sqd = x 3.5 -= 2.30ml/min Measured 20 ml /6.0min = 3.3ml/min
|
Olive Oil
|
Viscosity 43cps 37C 24cps 54C
|
Flow is proportional to 1/ viscosity
|
heating speeds up flow approx x2 for every +20degC
|
PROBLEMS ?
|
OK ! heat to help dissolve sample into “solvent” matrix generally let mix cool before filtration to below << 65deg C
|
On-Cooling the sample itself can crystallise out and completely block the filter membrane and even the Glass Frit or support base of the filter holder
|
Membrane Filter and Filter Holder
|
Max Temp
|
Check the MAX Temperature use for each !
|