Aquatec Watermaker AC 110, Technical Manual

Page: 12 / 38

12
Membrane cleaning.
Description:
When the fresh water production decreases more than 15 %, the membrane should be cleaned
chemically.
Warning!
Cleaning chemical no. 1 is alkaline and cleaning chemical no. 2 is an acid.
Please consider the hazard notes on the canisters. Working with chemicals,
please wear protective glasses, breathing protection and rubber gloves for your
own safety. Do must not mix different chemicals.
Instruction for cleaning of membranes.
Warning!
Make sure that you follow the following instructions carefully so that no cleaning
chemical gets into your fresh water tank.
Note!
Working pressure 0 bar!!!
1) Close the sea water intake valve.
2) The pressure control valve must be open. Turn the product water three-way valve (no. 2) to
position test-outlet to avoid that chemicals get into the drinking water tank.
3) Rinse the system with fresh water as described in “Fresh water flushing”.
4) Turn the three-way valve (no. 4) according to the flow diagram “Long term preservation
(mothballing) of the plant”. Open valve (no.1).
5) Blend about 10 liters warm chlorine-free fresh water, temperature app. 25° Celsius (77°
Fahrenheit), with chemical no. 1 (Alkaline), according to the instructions on the package and pour
it into the tank for conservation. (To avoid negative pressure, do not close the cap tightly) Since
there are about 1,5 litre of water already in each membrane and 1 litre of water in each filter,
please add the according amount of chemical to the water that has to be blended in every
membrane and filter.
6) Switch on the feed pump and the high-pressure pump. The unit is run for about 5 minutes to
circulate the solution through the membrane. Temperature of the solution must not exceed more
than 45° Celsius. Then allowed to rest for an hour, and then run again for 5 minutes. Perform
possibly exiting the test outlet liquid back into the preservative tank.
7) The chemical in the tank can be discharged overboard after turning the three-way valve (no. 4).
It should be noted that the system gets no air. Switch pumps off.
8) After this, the system is put back into service, unpressurized, and run for 15 minutes or so to
clear out the cleaning solution, before being returned to regular service. Once again, the initial
product water will need to be discharged for 30 minutes over the test outlet.
9) If there is no change in freshwater output, repeat the procedure 1 to 7 with chemical no. 2 (Acid).
Attention!
Prior to a longer period of shutdown, the Aquatec has to be preserved with
Biocide after cleaning and flushing.
Warning!
At every recommissioning after cleaning or mothballing, divert the product water
over the test-outlet for the first 30 minutes to rinse the chemical completely out
of the system.