Cooling System; Fluid Coolers; Air-Cooled Fluid Coolers; Water-Cooled Fluid Coolers - Quincy QGV-100 Instruction Manual

Section II - Description

Cooling System

Fluid Coolers

Fluid coolers may use either air or water
as a cooling medium. The following
descriptions point out the major
differences between the two types of
coolers.

Air-cooled Fluid Coolers

The air-cooled fluid cooler and aftercooler
are of the finned aluminum tube, one
piece design. Ambient air is forced
through the fins by a motor driven fan,
cooling the fluid and air in the tubes. To
maintain proper compressor operation,
the ambient air temperature should
not exceed the temperatures listed in
Appendix B - Technical Data. The cooler
fins must be kept clean at all times. Fluid
leaving the reservoir passes through a
thermal mixing valve before traveling on
to the cooler. The purpose of the thermal
valve is to maintain a minimum fluid
discharge temperature at the compressor
of approximately 80°F.

Water-cooled Fluid Coolers

Water-cooled fluid coolers are of the shell
and tube design. Fluid passes through
the shell transferring its heat to the water
flowing through the tubes. Fluid leaving
the cooler does not pass through a thermal
mixing valve as in an air-cooled unit, but
8
goes directly to the fluid filter and the
compressor. Fluid discharge temperature
at the compressor is maintained by a water
temperature regulating valve located
in the discharge water line. The water
temperature regulating valve uses a probe
to sense fluid temperature and opens and
closes, governing water flow through the
cooler.

Aftercoolers

Aftercoolers reduce the amount of water
in the discharge air. They are used to
lower the temperature of the discharge
air thereby condensing water vapor from
the compressed air. This allows most of
the contained water to be trapped and
expelled from the unit, reducing water
related problems downstream.
Air-cooled aftercoolers are part of the air-
cooled fluid cooler. Cooling air from the
fan is blown through the aftercooler and
the fluid cooler.
Water-cooled aftercoolers are placed in
series with the fluid cooler. Incoming water
is first directed through the aftercooler and
then on to the fluid cooler.
A combination moisture separator and
water trap is provided for collecting and
expelling water to the customer's drain.
Quincy Compressor-QGV Series