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5.5
Change polypropylene cartridge when it has clogged. Pressure
drop of 0,1 MPa or greater on the sediment filter indicates that filter
cartridge needs to be replaced as soon as possible.
5.6
Perform CIP or another suitable chemical cleaning protocol
when any of the following conditions are encountered:
–
permeate flow rate drops 10-15% of its initial value;
–
conductivity of permeate increases 10-15% of initial value, raw
water conductivity remaining at the same level;
–
pressure drop along the membrane module increases 10-15%
of its initial value.
5.7
After installing freshly cleaned membrane, perform 1 hour
rinse discarding all permeate and concentrate. If chemical cleaning
fails to restore normalized flow or rejection to design specifications,
membrane element is irreparably fouled and has to be replaced.
5.8
To prevent microbial contamination, the unit should be
operated for at least 1 hour a day. In case 48 hours or longer
shutdown is to occur, membrane should be treated with preservative
solution. Preservative treatment is accomplished by circulating 1%
sodium metabisulfite solution through the membrane module for
30 minutes or by preparing metabisulfite solution of the above
strength in the module. Before resuming operation of a machine that
had been treated with preservative, rinse the membrane.
Do not use raw water with over 0,1 mg/L of free chlorine
without pre-treatment with activated carbon or other means
of dechlorination. Chlorine will destroy the membrane.
5.9
To replace sediment filter cartridge proceed as follows:
–
remove the power from the unit;
–
shut off water supply and relieve pressure;
–
screw off filter bowl and remove it, taking care not to spill
water on parts of the unit;
