DRYING APPARATUS AND OPERATING METHOD THEREOF

摘要

A drying apparatus includes a heat pump apparatus having a main circuit and a bypass circuit 8A. In the main circuit, refrigerant is circulated through a compressor 1, a radiator 2, a first throttle apparatus 3A, a gas-liquid separator 4, a second throttle apparatus 5 and an evaporator 6 in this order. In the bypass circuit 8A, refrigerant flows from an upper portion of the gas-liquid separator 4 to the compressor 1 through a flow rate control valve 7. Air heated by the radiator 2 is introduced into a dry chamber 11, the heated air dries a subject to be dried 10 in the dry chamber 11, the air attracted moisture due to this drying operation is dehumidified by the evaporator 6, and the dehumidified air is again heated by the radiator 2. The drying apparatus includes flow rate control means 14 for controlling an operig degree of the flow rate control valve 7, thereby adjusting the opening degree of the flow rate control valve 7. With this, the drying apparatus can be controlled such that the radiator ability, the evaporator ability and the like are equal to each other. Therefore, unlike the conventional technique, the heat pump apparatus can be operated in a stable refrigeration cycle without discharging excessive heat quantity outside.