SnowPure Electropure EXL Series, Руководство по проектированию OEM, Страница: 78 / 81


SNOWPURE, LLC, 2005-2018 VERSION 3.5 (XL+EXL)
–FEBRUARY 2018
PAGE 78
Appendix #10: Procedure to Prevent Freezing of EDI Modules
This is SnowPure’s recommendation for the prevention of freezing of Electropure™
EDI modules. Freezing may take place either during shipment (by air or by land), or
in storage. Electropure™ EDI modules are shipped sealed, bacteria-free, and
drained of free water but still wet. No antifreeze or brine solution is added to the
modules before shipment. There are disadvantages to all added solutions, which will
be outlined below.
SnowPure’s Recommendation: Avoid Freezing.
As with pure water resin bead systems, the primary recommendation is to maintain
the temperature of the modules or packages above 2

C at all times. Brief exposure
of the packaged modules to freezing temperatures (for example in the cargo hold of
an airplane or the bed of a truck) may be tolerated since the packaging provides
insulation and the mass of the module provides thermal inertia. Avoid cyclical
freezing as this causes more damage than a single freeze.
Alternate Recommendation: Use USP Organic Antifreeze.
Certain non-
ionic organic chemicals may be used as “antifreeze solutions” to prevent
freezing of EDI modules. The problem with introducing organic chemicals into the
modules is the long time it takes to rinse them out. A 15% solution (by weight) of any
of these will provide about -5

C freeze protection (to 23

F). There are three
acceptable organic compounds that may be used:
1. USP grade Glycerol [CAS 56-81-5]
2. USP grade Propylene Glycol [CAS 57-55-6]
3. USP grade Glutaraldehyde [CAS 111-30-8]
The easiest of the three is Glycerol, since it will rinse out the fastest. The most
widely used of the three is Propylene Glycol. Glutaraldehyde provides bacteriological
protection in addition to antifreeze protection.
Procedure:
a) Prepare a 15% solution by weight of one of the above.
b) Circulate the solution by pump into all three streams (feed, concentrate,
and electrode).
c) Drain excess solution from the module/system.
d) Seal the module/system.
e) If the module/system freezes, be sure to let it thaw slowly.
f) To restore the system, first re-torque the bolts then flush the modules to
drain using RO or DI water for 15 minutes. Flush for an additional 4-24
hours with the system operating (DC power applied). Test for organic
(TOC) in the product and flush to drain until levels are acceptable to
customer. Flushing with warm water will accelerate the rinseout.
g) Sanitize the module/system if necessary.