| 摘要 |
PURPOSE:To terminate a combustion before an irregular combustion occurs by a method wherein an oxygen sensing element is arranged with a clearance against a flame opening of a burner, positioned in an air flow during normal operation, contacted with the combustion flame only in the case of a vertical flame combustion and at the same time the supplying of fuel for the burner is shut off when the sensed concentration of oxygen is decreased. CONSTITUTION:An oxygen sensing element 3 is placed in an air flow with a clearance against a flame hole 2 even in case that a burner 1 is in a combustion condition and its resistance value is decreased. In turn, when the combustible gas may not be ignited under its normal combustion flame height and extended due to a clogging of an air supplying filter and a poor rotation of the blower as well as deficiency of air and the like, the combustion flame may contact with the oxygen sensing element 3. Thus, the oxygen sensing element 3 senses a condition of deficiency of oxygen in the combustion flame to increase the resistance. Thereby, a supplying of fuel for the burner is shut off and the combustion in the burner 1 is terminated only when the abnormal combustion is occurred. |
