| 摘要 |
PURPOSE:To prevent self-oscillation of a proportional control valve during operation at a low flow rate, by a method wherein a resistor is located on the downstream side from the center of a pipeline on the outlet side, provided at its forward end with a burner nozzle and at its rear end with the outlet of a pressure regulating device, and on the upper stream side of an outlet for a gas pressure to a sensor. CONSTITUTION:A resistor 12 is located on the nozzle 7 side and apart by a distance of longer than a half the length of a line 11 on the outlet side from the outlet of a pressure regulating device 1. A secondary volume from a pressure regulating part to the resistor 12 is increased, the effect of compliance begins to be excercised, and acoustically, pressure waves reflected by the opening part and the shut-off part of the resistor 12, interfer with each other in the line 11 on the outlet side. The level of a reflecting component at a frequency zone in the vicinity of the resonant frequancy of the line 11 on the outlet side is decreased, Q of the resonant part of acoustic impedence of the line 11 on the outlet side is decreased, and this suppresses self-oscillation of the pressure regulating device 1. |
