Heatless Dryers remove water vapor from compressed air through the adsorption and pressure swing process. Using the twin towers and a solid state controller, compressed air is pushed through one tower where water vapor is adsorbed, some of that dried air is then pushed through the other tower to regenerate (purge) that off-stream bed of the moisture adsorbed during the previous cycle.

Externally Heat Reactivated Dryers use the twin tower adsorption method to remove water vapor from compressed air. To reduce the regeneration purge consumption required in heatless dryers, air is pushed through an external heater prior to being used for regeneration of the off-stream desiccant tower.

An external blower sends atmospheric air through a heater to be used for purging the off-stream desiccant tower. In this design all compressed air that enters the dryer can be utilized for the consumer’s process.