DRYING AND/OR PROCESSING OF MATERIALS

摘要

A drying and/or processing apparatus is disclosed having a chamber (10), fan means (14,30) for routing a proportion of a process gas entering a higher pressure region of the chamber (10) through a venturi device (32) so as to reduce the pressure at a duct opening into the high pressure region of the chamber (10). In one embodiment, heater means (18) are provided for heating the process gas whilst introducing little, if any, free oxygen into the process gas, along with an oxygen sensor (36) and water delivery means (38) operable to introduce a quantity of water into th? process gas in the event that the sensed free oxygen level exceeds a predetermined threshold.