| 摘要 |
PURPOSE:To protect the combustion apparatus against incomplete combustion that is possibly caused after long use of the apparatus, by providing shielding portions for restricting supply of the secondary air at a portion of burner flame and a sensor for detecting partial pressure of oxygen gas at a downstream portion of the burner flame on the outside of the flame where supply of the secondary air is restricted. CONSTITUTION:When a pilot burner 6 is ignited through manipulation of a cock or the like and flame F1 is formed by a burner 6, it is detected by a sensor 7 and a solenois valve 11 is opened and held in its open position by an electronic circuit 10. With subsequent ignition of the main burner 2 and formation of flame F2, temperature of a combustion sensor 9 disposed downwardly from fins 4 of a heat exchanger is raised and it is detected that fuel is combusted in a stable state. Here, if incomplete combustion of fuel is caused subsequently due to lack of air or by other reasons, flame F3 restricted of the secondary air by shielding portions 8 represents the state of incomplete combustion, and the solenoid valve 11 is closed by the output of the sensor 9 via the electronic circuit 10. |
