SnowPure Electropure EXL Series, Руководство по проектированию OEM

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
SNOWPURE, LLC, 2005-2018 VERSION 3.5 (XL+EXL)
–FEBRUARY 2018
PAGE 76
Procedure outline:
1. Isolate the resins by closing the concentrate and electrolyte ports and
valves. High pH cleaners will attack the concentrate screens and damage
them.
2. Slowly circulate the high pH cleaning solution through the EDI purifying
chambers. Ideal is to circulate the solution downward to keep the resin
bed packed (introduce the solution in the product port, collect it at the feed
port).
3. Monitor the pH of the solution, and reformulate if the pH drops below 10.5
4. Treat for at least 60 minutes.
5. Neutralize and dispose of cleaning solution according to local waste
treatment regulations.
6. Rinse the module with DI water, downward if possible, until the effluent is
below pH 9. This may take some time since the NaOH has permeated
the resins and the membranes.
7. The anion resins and membranes will be fully in the OH- form.
8. The cation resins and membranes will be fully in the Na+ form.
9.
Operate the module under “regeneration” conditions with product and
concentrate and electrode flow all flowing to drain. This may take 8-16
hours to fully remove the excess Na
+
ions. Monitor the pH and
conductivity of the concentrate to watch the progress. The pH of the
concentrate should be acidic, and lower than the pH of the EDI feed.
10. It is expected that the quality of the EDI product will decline with each
cleaning. This is why it is better to avoid fouling/cleaning by using the
best pretreatment possible.
Suggestion : Use 3-way valves in the design of a CIP system to eliminate the need to
manually disconnect the plumbing when servicing the EDI module.
Caustic Cleaning Solution Formula 1:

9.8 liters deionized water

200 ml RoClean
tm
L211 solution (100 ml for mild fouling), available from Avista
Technologies. The pH will be 10.5-11.0. Technical specification sheet and
MSDS available at www.snowpure.com/knowledgebase.

The solution should be heated to 45-50°C for aggressive cleaning.
Caustic Cleaning Solution Formula 2:

9.8 liters deionized water

Sodium Hydroxide (pure NaOH) to make a 0.1-0.5% solution. Target pH 12-13.

The solution should be heated to 40-50°C for aggressive cleaning.
Procedure:

Do not “brine” the resins with NaCl salt or the EDI product quality will never
recover.

Plug the concentrate and electrode inlet and outlet ports. Isolate the Feed and
Product ports from the RO and the product plumbing.

The cleaning of the resins is DOWNWARD FLOW.