Thermal dehydration of bulk material esp. food prods. - such as fodder, cereals, meat, fish and vegetables

摘要

The prod. is heated in an enclosed atmosphere to vapourise the contained moisture. The temp. is maintained while the water vapour is drawn off in an atmos. air current and the prod. is then cooled. The prod. is pref. heated to about 70 degrees C by being conveyed along heated constant surfaces while agitated. Cooling is pref. effected by blowing ambient air through the prod. The heated contact surfaces pref. form parts. of a series of horizontal tunnels through which the prod. is advanced by scrapers bringing the prod. into contact with the heated surfaces. These surfaces are pref. heated by hot gas, partic. from an air heater, flowing along the side of the surface remote from the prod. Uniform treatment throughout the bulk material with indirect heating and agitation ensures efficient dehydration without loss of nutritional value in proteins and vitamins.