| 摘要 |
PURPOSE:To secure safety by providing a plurality of exhaust gas suction tubes of different heights on a flame, allowing the tubes to communicate with an oxygen concentration battery, and forming an exhaust gas suction port switching unit in the course, thereby detecting in advance the oxygen shortage state of a chamber to stop the combustion. CONSTITUTION:When oxygen concentration in a chamber is normal, the outer peripheral electrode surface of an oxygen concentration battery 5 becomes oxygen lacking state by a flame 4a, while the inner peripheral electrode surface is contacted with exhaust gas which is introduced to a suction tube 6 but since the height of the flame 4a is low, high concentration oxygen exists in the exhaust gas, and a high voltage signal is fed from the battery 5 to open a solenoid valve 3. When the interior of the chamber is oxygen lacking state, a flame 13a extends as shown to reach an opening surface. Accordingly, a voltage drops, the valve 3 is closed, and the combustion is stopped. When the chamber temperature rises so that the combustion amount is switched to weak state, the flame 4b becomes low as shown, and safety can be secured by switching to a suction tube 7. |
