Patent ID: 8684512

Claim:
An ink drying apparatus comprising: a gas passage which is circulatingly defined and is configured such that a gas can be circulated in the gas passage, wherein a printed material passes through a part of the gas passage; a fan to form a flow of the gas such that the gas in the gas passage flows in a given direction for circulation; a heater to heat the gas in the gas passage, the heater being provided upstream of the part of the gas passage through which the printed material passes; a radiator to which a radiating part is connected, the radiating part being exposed to an inside of the gas passage to heat the gas in the gas passage, the radiator being provided upstream of the part of the gas passage through which the printed material passes; and an endothermic device to which a cooling part is connected, the cooling part being exposed to an inside of the gas passage to cool the gas in the gas passage, thereby condensing an ink solvent, the endothermic device being provided downstream of the part of the gas passage through which the printed material passes and upstream of the radiating part, wherein the radiator and the endothermic device are associated with each other such that heat can be transferred therebetween by a heat pump system having a compressor and an expansion valve, wherein the heat pump system comprises a circulating coolant passage, in which the radiator, the expansion valve, the endothermic device and the compressor are arranged in the listed order along a direction of a coolant flow in the coolant passage, wherein when the heat pump system is operated by driving the compressor and the expansion valve, the radiator is heated by the coolant in a high-temperature and high-pressure state, which has passed through the compressor, to result in a part of the heat transmitted from the radiator to the radiating part and the endothermic device being cooled by the coolant in a low-temperature and low-pressure state, which has passed through the expansion valve, to result in a part of the heat transmitted from the cooling part to the endothermic device, and a part of the heat transmitted to the endothermic device is transmitted to the coolant flowing in the coolant passage, thereby to be returned back to the radiator, and wherein the gas heated by the heater and the radiating part promotes the drying of the ink attached to the printed material, and then the ink solvent generated by the drying is condensed in the cooling part.