Dryer Operation Continued

After some time, the tower on the left hand side gets saturated with moisture and its ability to absorb moisture diminishes. At that time, the towers are switched. The right hand tower is put in service while the left hand tower is regenerated.

The switching process is carried on by the two four-way valves shown at the middle of the two towers. These valves are able to rotate and route incoming air to the left or the right tower. Similarly the outlet and the purge connection can be made to the left or the right tower.

Usually the tower switching is controlled by a timer.