Side 11 af 16
The following procedure should be repeated for each bank of membranes to be cleaned.
Detailed Cleaning Procedure
1.
Flush Train
The train to be cleaned should be shut down and flushed with dechlorinated potable water
until the brine and feed conductivities are within 10% of each other (approx. 10 minutes).
2.
Acidic Wash
A 2% w/v solution of RoClean P303 should be made up by adding 1kg of RoClean P303
per 50 litres of heated potable water. The water should be heated to a minimum of 15
o
C
and a maximum of 45
o
C. The total volume of cleaning solution required should be detailed
in your Operating and Maintenance manual.
Once the solution is mixed and the pH has been verified to be 2.5>pH<3.5 introduce the
cleaning solution to the (feed/brine side of the) plant at a low flow and displace the flushing
water to drain before diverting the flow to the CIP tank. Keep the cleaning fluid in contact
with the membranes for a total of 2 hours stopping and starting the recirculation pump
every 15 minutes to allow deep soaking and scouring action on the foulant layer. The
recirculation flow should be increased to the point where the differential pressure reaches
40psi or where the flow reaches 10 m
3
/hr/pressure vessel.
Note the pH, temperature, differential pressure, flowrate and any discolouration/changes to
the cleaning solution on a half hourly basis as before.
At the end of this period pump the solution out of the system and drain down to remove as
much solution as possible.
3.
Flush out Remaining Acidic Solution
Rinse out the cleaning tank and then fill it with un-chlorinated potable water. Rinse each
pressure vessel until the conductivity of the outlet is within 20% of the inlet.
4.
Make Up High pH Cleaning Solution and Circulate It
A 2% w/v solution of RoClean P111 should be made up by adding 1kg of RoClean P111
per 50 litres of heated potable water. The water should be heated to a minimum of 30
o
C
and a maximum of 45
o
C and it should be confirmed that the pH of the solution is between
10>pH<11.
Introduce the cleaning solution to the (feed/brine side of the) plant at a low flow and
displace the flushing water to drain before diverting the flow to the CIP tank. Keep the
cleaning fluid in contact with the membranes for a total of 2 hours stopping and starting the
recirculation pump every 15 minutes to allow deep soaking and scouring action on the
foulant layer. The recirculation flow should be increased to the point where the differential