PHL – Heatless Dryer
A typical heatless dryer includes two towers filled with desiccant, activated alumina, or molecular sieve. One tower, the initial tower, dries the air while the other tower, is re-generated. As the air flows through the initial tower, the desiccant absorbs moisture, its pores capture and hold moisture, and the dried air flows out of that tower. When the initial tower is saturated, the towers switch roles.
A portion of the dry air, called the purge air, is depressurized to near atmospheric pressure. It then flows through the saturated tower and re-generates its desiccant. The wet purge air is then discharged to atmosphere through a silencer or muffler.