To provide a direct fire gas burner furnace capable of maintaining a furnace interior at a set temperature while reducing exhaust heat loss, saving energy, and reducing a CO2 exhaust amount.
In the direct fire gas burner furnace, an object 13 to be heated is directly heated by combustion gas, and the combustion gas is exhausted out of the furnace. An exhaust amount of the combustion gas in the furnace is controlled by controlling a burning capacity of a gas burner 2 on the basis of an in-furnace temperature detected by a temperature sensor 3 in the furnace, and controlling a rotational frequency of an exhaust fan 8 on the basis of the burning capacity. Consequently, combustion gas of an amount appropriating an amount of the combustion gas introduced into the furnace can be exhausted out of the furnace, and suction of outside air of an ordinary temperature into the furnace can be prevented.
Jun Tsuruta
Shinozaki Masami
Masaya Nishiyama