Freezing Weather Operation - SPX Cooling Technologies MH Fluid Cooler User Manual

Note
Caution
operation

Freezing Weather Operation

The Marley film-fill system used in the MH Fluid Cooler has air entrance louvers
that are molded as an integral part of the fill. This feature makes these fluid
coolers very forgiving of cold weather operation, even at the low temperature
and reduced load conditions encountered in low temperature applications.
Nevertheless, during operation in subfreezing weather, the opportunity exists
for ice to form in the colder regions of the fluid cooler.
Slushy, transitory ice forms routinely in the colder regions of the
fill of low temperature fluid coolers, and is visible through the fluid
cooler louvers. Such ice normally has no adverse effect on fluid
cooler operation, but its appearance should be a signal to the op-
erator to undertake ice control procedures.
It is the operator's responsibility to prevent the formation of destruc-
tive (hard) ice on the fluid cooler fill. Certain guidelines should be
followed:
1. Do not allow the fluid cooler's leaving process fluid temperature to drop
below 7°C. If such low temperature operation is necessary or beneficial
to your process, establish the minimum allowable level as follows:
During the coldest days of the first winter of operation, observe whether
any ice is forming on the louver face, particularly near the bottom part of
the louver face. If hard ice is present on the louvers, you must increase
the allowable cold water temperature.
If the minimum allowable cold process fluid temperature is es-
tablished at or near minimum heat load, it should be safe for all
operating conditions.
Having established the minimum allowable cold water temperature,
maintaining that temperature can be accomplished by fan manipulation,
as outlined in Item 4 under Fluid Cooler Operation.
2. As cold air enters the louvers, it causes the water flowing over the fill to
be drawn inward toward the center of the fluid cooler. Thus, under fan
operation, the louvers and lower periphery of the fluid cooler structure
remain partly dry, seeing only random splashing from within the fluid
cooler—plus normal atmospheric moisture from the entering air. Such
lightly wetted areas are most subject to freezing.
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