| 摘要 |
PURPOSE:To improve an accuracy of sending of oxygen deficience when a weak combustion is performed by a method wherein a semiconductor sensor for a discharged gas of a combustion safety device in a double stepped combustion change-over gas combustion unit is arranged at a positon corresponding to a strong combustion flame and at the same time an intermittent strong combustion is performed when a weak combustion is performed. CONSTITUTION:Strong combustion flame is set at a condition F1 when a strong combustion is performed, and then returned back to a condition F2 when oxygen is reduced, resulting in that the hood 8 is convered to eliminate a bi-flow of air to cause the electrode 7a in the sensor 7 to show a low electromotive force and to operate the safety valve 3. When weak combustion is found, even if a lift-up phenomenum is occured, no covering of the hood 8 by the lift-up flame F2 is made and the sensor 7 is not operated thereby. Therefore, when the weak combustion is performed, a volume of inermittent supplying of gas is increased to enable the lift-up flame to cover the hood with the flame being set to a strong combustion condition. Thereby, a positive sensing of lack of oxygen may be performed whenever a strong or a weak cmbustion is made and a safety device may be operated. |
