There are several ways to remove water and moisture from compressed air: cooling, over compression, absorption, adsorption. Adsorption dryers are used when the compressed air application requires a pressure dew point below 0°C.
The Adsorption air dryer is composed typically of two towers, one in operation and one in regeneration phase, the operation cycle is repetitive and controlled by a timer. Compressed air, after pre-filtration, enters the working tower at the lower and flows upwards through the tower, the desiccant adsorbs the water vapor drying air. Once the top of the tower is reached, the air leaves the dryer via check valve.

There are two major techniques to regenerate the desiccant beads: Cold regeneration: a small portion of dried compressed air is expanded to atmospheric pressure and sent over the saturated vessel of desiccant.Heat regeneration: By heating the beads, the Van Der Waals forces are broken and the moisture is released from the beads. An air flow transports the moisture away from the saturated vessel.