Drying Desk: Closed-cycle drying -- What? When? How?
Closed-cycle drying doesn’t emit any vapors to the atmosphere. (This is unlike open-cycle drying, in which noncondensable gas, carrying along with it the moisture or the volatile component evaporated during drying, is exhausted into the atmosphere.) The moisture evaporated during closed-cycle drying is recovered separately along with the dried product, which can be an advantage in many applications. A closed-cycle drying system can operate in continuous or batch mode and under atmospheric pressure or vacuum conditions. For simplicity, this column will address continuous closed-cycle drying under atmospheric pressure.