16
Start up of cassettes
2.7 Cassette Cleaning
Filter cassettes should be cleaned after every filtration run to prevent a sedi-
ment layer build-up on the membrane and in the retentate channels. Over time,
this layer becomes compacted, making it difficult to remove completely. As a
result, this will decrease the flux rate of your filter cassettes and reduce their
lifespan.
We recommend the following cleaning agents and conditions for the various
membrane materials. This table gives suggested procedures only; requirements may
vary in individual cases:
Cleaning agent
Concentration pH
Time [min] Temperature [°C]
Sodium hydroxide 1 N
14
60
50
Phosphoric acid
2% by weight
1.3
30
50
Adjust the following pressures:
p
inlet
= 29 psi|2.0 bar|200 kPa
p
ret
= 0 psi|0 bar|0 kPa
Ultrafilter cassettes:
Recirculate cleaning solution with permeate valves open for 60 minutes.
Repeat as required.
Flush the filter cassettes with purified water as described in
“Flushing the Filter
Cassettes”
. Determine the flux rate of the cleaned cassette as described in
“Determining clean water flux for filter cassettes”
. Compare results with the
previously determined clean water flux (CWF). It is normal to have a greater drop in
clean water flux rate after the first processing and complete cleaning. Good cleaning
practice will result in less water flux deviation.
If the flux rate remains below this level after further cleaning attempts, please
contact your local Sartorius Stedim application specialist.
Generally, the Sartorius product and material limitations, especially regarding pH and
temperature stability of the membranes and cassettes, must be adhered to.
The Sartorius INCREASE
®
Program offers evaluation of product specific cleaning
procedures.
Detection Method of NaOH cleaning agent clearance:
t
Neutral pH effluent in both retentate and permeate.
t
Conductivity.
Summary of Contents for Sartocon ECO Series
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