Drying air by freezing - esp for compressed air with continuous removal of precipitated ice

摘要

A continuous method of drying humid gases, esp. compressed air, operates by freezing out the moisture the air is cooled to a temp. below the freezing point of its required residual humidity in a coolar; the moisture is removed as ice or frost from the cooling surfaces by mechanical or pneumatic means as it is deposited and the dried air and ice are separately removed. Preferably, the air is precooled to just above the freezing point for the moisture, the negative heat energy from the dried air being optionally used in part of the pre-cooler. The humidity is partially removed as condensate. In the preferred apparatus, the precipitated ice is continuously removed from the cooling surfaces pneumatically, e.g. by pellet-bombardment, by mechanical scrapers or by having the cooling surfaces themselves elastically deformable.