Principle Of Operation; Compressed Air Heat Exchanger - Sullair RH Series User & Service Manual

SECTION 3

3.11 PRINCIPLE OF OPERATION

The refrigerant circuit can be divided in 3 parts:
1. Low pressure section with an evaporator
(heat exchanger)
2. High pressure section including: Condenser,
liquid receiver, (if installed) and the filter
dryer.
3. Control circuit including: Compressor, meter-
ing device, hot gas by-pass valve (if
installed), fan pressure switch, safety high/
low pressure switch. Water cooled dryers are
equipped with a
valve.Refrigeration Heat Exchanger
4. The compressor compresses gaseous refrig-
erant.
5. The hot refrigerant gas condenses in the
condenser and once liquefied it passes
through the liquid receiver (optional)
6. The liquid refrigerant leaves the liquid
receiver and is injected into the evaporator
(heat exchanger) by a metering device.
7. This metering device is protected by a filter
dryer, that retains particles and humidity that
could be in the circuit
8. The injected liquid evaporates (changes
states from liquid to gas) by absorbing heat
from the compressed air.
water flow control
The gaseous
PRODUCT USER MANUAL
refrigerant is sucked into the compressor
and the cycle carries on.
9. In order to keep the evaporation pressure
steady, and maintain the refrigerant tempera-
ture in the heat exchanger, a hot gas by-pass
valve injects hot gaseous refrigerant into the
low pressure refrigerant circuit.
3.12 COMPRESSED AIR HEAT
EXCHANGER
1. The saturated, hot compressed air flows into
the air/air heat exchanger where it is pre
cooled by the out going chilled air.
2. The compressed air then enters the evapo-
rator where it is cooled to the desired dew
point.
3. The cooled compressed air passes through
the air/water separator where the liquid con-
densate is removed by the centrifugal sepa-
ration and drained away by the automatic
trap. The outgoing, chilled air is then warmed
up in the air/air heat exchanger by the hot
incoming air. This energy efficient air-to-air
heat exchanger significantly reduces the
load on the compressor.
4. As long as the compressed air temperature
does not drop below dew point, there will be
no further condensation in the compressed
air piping.
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