WHAT IS AN INTERNAL HEAT REACTIVATED DRYER?
These dryers use heaters installed in the desiccant bed to reactivate the desiccant. The heaters can be multiple elements installed in heater wells or, in some cases, installed in a single heater well in the center. The multiple heater element arrangements are typically more efficient. These dryers also use the least amount of purge (typically 3% of the process air) of any dryer because of the high efficiency of the multiple element arrangements. Where other heat reactivated dryers use purge air calculations directly linked to inlet air flow rates and loadings, this dryer purge flow is independent of the inlet conditions and is a function of dryer size only.
