In this type of dryer, the wet compressed air / gas is made to pass through one of the two towers at a time. The direction of flow of air / gas is controlled with the help of automatically operated valves. As the moisture-laden air passes through the desiccant bed, the desiccant adsorbs the water molecules and dry air comes out from the top. After a particular level of saturation of the desiccant bed, an automatic changeover of the tower takes place. As the second tower comes on the adsorption line, the first tower is simultaneously depressurized. This depressurization is followed by purging the depressurized tower with a small quantity of dry air / gas from the 2nd tower.

As the dry air / gas traverses the adsorbent bed in the counter current direction, it picks up the moisture and reactivates the desiccant bed. This moisture-laden gas is now vented out to the atmosphere through the exhaust valves. To avoid pressure jolts, the reactivated tower is re-pressurized before changeover.

In this type of dryer, the wet compressed air / gas is made to pass through one of the two towers at a time. The direction of flow of air / gas is controlled with the help of automatically operated valves. As the moisture-laden air passes through the desiccant bed, the desiccant adsorbs the water molecules and dry air comes out from the top. After a particular level of saturation of the desiccant bed, an automatic changeover of the tower takes place. As the second tower comes on the adsorption line, the first tower is simultaneously depressurized. This depressurization is followed by purging the depressurized tower with a small quantity of dry air / gas from the 2nd tower.

As the dry air / gas traverses the adsorbent bed in the counter current direction, it picks up the moisture and reactivates the desiccant bed. This moisture-laden gas is now vented out to the atmosphere through the exhaust valves. To avoid pressure jolts, the reactivated tower is re-pressurized before changeover.