Drying system with energy recuperation - uses main heat pump followed by auxiliary modular heat pump units in axial arrangement

摘要

The method of supplying hot air for drying bulk material carried through a drying chamber on a belt conveyor (1) uses a system of heat pumps. At the feed end of the belt, the incoming air is passed through the condenser coil of a heat pump circuit (A). The air may be heated by heaters at this point. At the delivery end the air is extracted through a duct containing a dust separator (7) and the evaporator coil (8) of the heat pump. At a position further along the conveyor belt (3) is an evaporator coil (18), followed by a condenser coil (19) of a second heat pump (B) under a hood enclosing the conveyor. At a second position nearer the discharge end are evaporator and condenser coils (28,29) of a second heat pump (C). These two heat pumps are modular units, each with its own drive (MB,MC) and throttles (DB,DC) etc. Alternative types of drier use similarly distributed heat pump circuits.