Drying powdered substances in hot conveying gas - which flows through tube with electrical resistance heating to improve drying effectiveness

摘要

A pulverulent substance is dried by heating as the substance is conveyed by a carrier gas through a drying tube which is heated by electrical resistance heating. Pref. the carrier gas is recycled and, before it reenters the drying tube, is heated up by contact with the outer surface of the tube. The carrier gas is pref. an inert gas. By conveying the powder in a hot gas through a tube the walls of which are additionally heated, much more effective drying is obtainable and much higher drying temps are achieved than with simple hot gas drying.