Page 19 - PNEUMATIC AND HYDRAULIC

1.2.5 Drying by Refrigeration (Low Temperature Drying)

1. Refrigerated air dryers remove moisture and contaminants from compressed
air by chilling the air to a temperature that causes the moisture in the air to

condense and form droplets.
2. These can be separated from the air stream and discharged from the dryer.

3. This is the principle applied in drying of air by refrigeration, the compressed

air thereby being cooled to temperatures between about 1.7 and 5 degrees
Celsius.

4. This type of dryer uses;
a. a refrigeration system (one for air-to-refrigeration)

b. heat exchanger (one for air-to-air)

c. separator and drain
4. Drying by refrigeration is only suitable for pressure dew points over 0

degree Celsius.

Figure 1.12: Low Temperature Drying Process

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