| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the generation of high ignition noise even when an ignition error occurs and to prevent the occurrence of a lift of a combustion flame at the initial stage of ignition by a method wherein during a period between firing of a burner and ignition of the burner, an on-off valve to open and close an exhaust gas flow passage is closed. SOLUTION: A combustion device comprises an exhaust gas reflux passage 5 to effect reflux of a part of exhaust gas H to a fan 4; a solenoid valve 6 for reflux disposed in the exhaust gas reflux passage 5; and a controller 7 to control opening and closing operation of the solenoid valve 6 for reflux and combustion of a gas burner 2. When, even in a case firing operation of the gas burner 2 is effected, an electric output of a flame rod 81 is below a given value, no energization is effected on the solenoid valve 6 for reflux and the solenoid valve 6 maintains a closing state. Thereby, even when, during the starting of ignition, an ignition error occurs and unburnt gas is discharged from a gas burner 2 to a combustion housing 1, high ignition noise is prevented from generating.</p> |
