GAS OR VAPOR CONTACTING TYPE DRYING METHOD

PROBLEM TO BE SOLVED: To provide a drying method in which circulating heating medium gas is heated up to sufficient high temperature to improve a drying capacity with the heating medium gas. SOLUTION: A gas contacting type drying device 21 is provided with a heater 40 and a heating medium gas circulating flow passage connected to a drying machine 43. Heating medium gas G21 passes through the heating medium gas circulating flow passage and circulates between the heater 40 and the drying machine 43. The heating medium gas G21 is heated by the heater 40 and then mixed furnace gas G26 of high temperature generated at a heat source furnace 23 is mixed with the heating medium gas G21 and then the heating medium gas G21 is further heated. The heating medium gas G21 showing a sufficient high temperature through two stages is contacted with an object 22, to be dried in the drying machine 43 and then the object 22 is dried. Since the heating medium gas G21 is heated by mixture of the mixed furnace gas G26, the circulating heating medium gas G21 can be reheated up to a sufficient high temperature irrespective of a limit of heat-resistance of a heat transferring metal of the heater 40. It is possible to improve a drying capacity with the heating medium gas G21.