Function; Functional Description - Comprag Rdx Serie Bedienungsanleitung

2.2 Function

RDX series compressed air refrigerating dryers are designed for removing condensate
from compressed air entering the compressed-air line from a compressor.
Air drying takes place by means of cooling the flow of compressed air to a temperature at
which water vapour, present in the compressed air, reaches saturation point (dew-point) and
turns from gaseous state to liquid. Condensate formed this way is extracted by the conden-
sate drain valve, which is actuated at set intervals on a time relay.

2.3 Functional description

1. Refrigerant compressor
2. Evaporator
3. Condenser
4. Fan
5. Filter dryer
6. Evaporator temperature sensor
7. Expansion valve
8. Low pressure pressure switch
9. Condensate drain valve
10. Condenser temperature sensor
Fig. 2.1 Flow chart of compressed air dryer
The refrigerant compressor (1) compresses the gaseous refrigerant in the condenser (3),
where the majority of the refrigerant changes into the liquid phase. The liquefied refriger-
ant is passed through the filter dryer (5), injected into the Evaporator (2) via the expansion
valve (7) and vaporized, where it absorbs the heat from the compressed air. Due to the heat
exchange between the compressed air and the refrigerant, the refrigerant changes into the
gaseous state. This cycle repeats itself continuously. The refrigeration circuit is equipped
with an expansion valve (7) for adapted refrigeration to the changing load conditions. The
temperature in the Evaporator (2) is kept constant and the pressure dew point never drops
below +3° C in order to prevent the Evaporator (2) from icing up.
COMPRAG RDX series compressed air refrigerated dryer
2
7
6
9
5
8
1
4
Refrigerant
Compressed air
10
3
11