Use RO permeate water if possible.
Whether the Membranes need acid or alkaline cleaning will depend on the type of foulant
suspected. We recommended acid cleaning be performed first even when alkaline
cleaning is desired. If
Membrane performance recovers with acid cleaning, then
alkaline cleaning is not necessary.
Membrane Cleaning System
Connect cleaning tank and pump system to the membrane system.
It may be necessary to clean one tube at a time (see flow requirements below).
Pump pressure must not exceed 60 psi. Permeate and concentrate lines must
return to the cleaning tank. Include a 10 micron filter in the concentrate return
line to the tank.
Membrane
Cleaning Procedure
- Preparation of Solution
Add slowly the cleaner (for amounts check the detailed procedure for that cleaner)
cleaning tank water, and mix well.
CAUTION Mix with care and wear protective clothing.
- Cleaning Procedure
CAUTION Do not allow the cleaning solution temperatures to
exceed 120°F or the flows to exceed 4 gpm for 2½" elements or 12 gpm for 4"
elements or 40 gpm for 8" elements. Recirculate solution.
- Operate system at 50 psi for 10 minutes.
During this first 10 minutes of the cleaning cycle, the flow rate should be maintained at
less than 1 gpm for 2½" elements and 9 gpm for 4" elements and 35 gpm for
8" elements for 20 minutes to clear foulants from the system.
- Do not let tank run dry. Add more water
and cleaner if necessary
- Discard cleaning solution to drain, diluting
with copious amounts of water, then rinse tank well.
- Fill tank with clean water and flush system to
drain for 10 to 15 minutes.
Add clean water as necessary. Rinse the system until the concentrate pH is
almost the same as the clean water pH.
CAUTION:
Flush thoroughly before cleaning with other
cleaners. Cleaning chemicals may react with one another or foulants to produce
additional fouling on the membrane.
