| 摘要 |
PROBLEM TO BE SOLVED: To detect a clogging at a burner or a flue and an inverse flow of discharged gas from the flue easily and positively and perform a positive prevention of gas leakage to outside and improve its safety characteristics.SOLUTION: A gas suction mechanism 6 is provided with a Venturi pipe 13 and arranged at a suction port 5a of a blower 5. The gas suction mechanism 6 has a gas supply passage 7 connected to a throat part 13a of the Venturi pipe 13 and as the air is sucked into the blower 5 through the Venturi pipe 13, gas is also sucked through the gas supply passage 7 and fed into the blower 5 together with the air. A gas pressure adjusting valve 8 arranged at the gas supply passage 7 adjusts its degree of opening to keep the gas pressure at the outlet at an inlet side pressure of the Venturi pipe 13 or the atmospheric pressure. A pressure difference between the inlet side pressure of the Venturi pipe 13 and a pressure at the throat part is monitored by differential pressure monitoring means 9.SELECTED DRAWING: Figure 1 |
