Freezing water removal is one of the main methods of compressed air drying. The principle is to use the pressure to maintain a constant temperature and humidity in the wet air with the decline in the nature of the.
Freeze drying machine (cold dryer) is the most widely used compressed air water removal equipment. Cold and dry cooling technology using the machine, into the dryer humidity saturated compressed air temperature is suddenly reduced, forcing most of the water vapor (steam and oil) is condensed into liquid water (oil), and separated from the air after the compressed air temperature to a higher temperature to reduce the relative humidity after delivery to downstream gas equipment.
In the compressed air refrigeration dryer, because in the evaporator, the compressed air is always saturated, in the circulation process will continue to precipitate condensation water, and its dew point will also fall - the limit is the freezing point of water. It is due to the freezing point of the limit, the evaporation temperature cannot freeze dryer refrigeration system as a refrigerator that is set too low, which limits the further decline of compressed air dew point, so the compressed air refrigeration dryer with dryness (moisture) is limited. Under normal circumstances, no matter how much pressure the compressed air, the working pressure of the dew point (referred to as "pressure dew point") are above zero, the general 2-10 as a symbol of its purification efficiency.