| 摘要 |
PURPOSE:To stabilize combustion at all times even when the pressure of a combustion chamber is fluctuated, by a method wherein a venturi unit is provided between a burner and a fan to detect pressure difference in between and the output of the fan is controlled so that the pressure difference is matched with the supplying amount of fuel. CONSTITUTION:A venturi unit 11 is provided in the supplying passageway 5a of combustion air, which connects a burner 4 and a fan 5, while a pressure difference detecting device 10 is connected to the supplying passageway 5a on upstream and downstream of the venturi unit 11. The load of a combustion device is operated by a control unit 7 by comparing the signal of an output hot-water thermistor 12, provided at the outlet port of a heat exchanger 2, with a set temperature to determine the output (supplying amount of gas) of a gas control valve 6 in accordance with the operated load. On the other hand, the control unit determines the output (torque) of the fan 5 so that the pressure difference, detected by the pressure difference detecting device 10, becomes equal to the pressure difference of the venturi 11 in accordance with the determined output of the gas control valve 6. The fan 5 is rotated by the signal of the control unit 7 to supply the combustion air. According to this method, combustion may be stabilized even when the fins of the heat exchanger are clogged by soot or the like. |
