Adsorption drying is a common method for preparing dew point below zero degree of compressed air. The principle is to use some of the material that has the ability to absorb water, known as adsorbent (active alumina) to absorb the moisture in compressed air.
In a dryer, adsorbent in adsorption was reduced to a certain water in the air after itself will reach saturation state (known as the "equilibrium"), you must will have reached the adsorption equilibrium state of adsorbent dehydration -- a process called adsorption desorption, and the adsorption capacity to recover the original state of this process is known as adsorbent regeneration".
When the water vapor in the compressed air is contacted with the surface of the adsorbent, the adsorption process can be carried out immediately without the external energy. But the desorption process is not spontaneous, but must be fully involved in the external energy to complete. The regeneration method of adsorbent and regeneration energy consumption are the main factors affecting the operation of adsorption dryer.
The dryer compressed air dew point can reach very low (compressed air pressure dew point is -20 ~-40 degrees), so in need of dry compressed air apply.so adsorption dryer is most widely used.