| 摘要 |
PURPOSE:To prevent the base plate and backer plate of the valve mechanism part of air flap valve from the dew condensation of vapor by equipping the temperature regulation mechanism together with providing a heating body to heat the base plate and backer plate respectively. CONSTITUTION:Where the temperatures of the base plate 19 and backer plate to be detected by the temperatue detector 27, 28 are lower than the specified dew condensation preventive temperature, an electric current is sent to the heater before the pulse combustion begins, and the plate 19 and plate 20 is heated respectively. When the temperatures of 19 and 20 reach not lower than the specified dew condenstion preventive temperature, the sending of electric current to 25 and 26 is stopped. At the same time, the air for combustion and the gas for fuel are supplied in the combustion room and the pulse combustion begins. From the reasons stated above, it is not feared that the vapor, included in the combustion gas during the pulse combustion, produce the dew condensation at the base plate, the backer plate and the like of the valve mechanism part 5. |
