heated air dryer

Adsorption devices are commonly installed in compressed air systems to remove moisture.  Heatless compressed air dyers are the most common type furnished to meet the requirement for -40° F dew point “commercially dry” air, especially in systems of less than 1,000 standard cubic feet per minute (scfm).  Heatless air dryers are pressure swing adsorbers designed to retain the heat of adsorption within the desiccant beds during the drying process. 

The stored heat of adsorption is consumed during the regeneration process to remove moisture from the desiccant to provide continuous service.  If the heat is lost prematurely, such as by excessive flow rates, the heatless dryer cannot regenerate and the system fails requiring priming at minimal flow for an extended period of time before continuing.  The dryer is heater-less, but it relies on the retention of the heat of adsorption evolved during the drying process to provide continuous service.