Heatless Type Dryer By Airro Engineering Co.

Wet incoming compressed air or gas is passed through a desiccant bed; the desiccant adsorbs its moisture. After some time of operation, this desiccant gets saturated and needs regeneration. Reactivation or regeneration of desiccant is then necessary to drive-off the adsorbed moisture and to re-store its original adsorptive capacity. This is accomplished via purging the adsorbent by dry air or gas at atmospheric pressure and temperature in reverse direction.

ACTUAL OPERATION
Heatless Drying Unit has two towers filled with the desiccant for continuous drying operation. At a time, one tower is used for drying while the other tower is reactivated simultaneously. After a fixed time of interval, the drying towers get changeover automatically by operation of sequence timer and interconnected valves.

Referring to the flow diagram, assume that the left tower is under DRYING and the right tower is under REACTIVATION. Wet air or gas enters the tower from bottom side, passes up through the desiccant and comes out from the top. A small bleed flow is split from the exit of left tower and enters the right tower at atmospheric pressure. This bleed air pick-up the moisture from the desiccant and vented out to the atmosphere. After complete reactivation of desiccant, direction of control valves is reversed to place the left tower on reactivation and right tower on drying.