| 摘要 |
PURPOSE:To minimize gas pressure loss, in a gas pressure control system, by a mechanism wherein two controller chambers which are connected to each other are installed, with the outlet of the one of the differential pressure drive system leading to a place near the combustion heat source for ignition. CONSTITUTION:The primary pressure chamber (a) of the No.1 controller chamber 18 and the primary pressure chamber (b) of the No.2 controller chamber 22 are connected through the No.1 passage 23. The back-pressure chamber (c) of the No.1 controller chamber 18 and the secondary pressure chamber (d) of the No.2 controller chamber 22 are connected through the throttle 24. The differential pressure producing orifice 25 is provided downstream from the secondary pressure chamber (d) of the No.2 controller chamber 22. The downstream of the orifice 25 is connected to the backpressure chamber (e) to enable ignition near the burner 14 via the guide pipe 27. The force F of the driving unit 28 activates the No.2 valve of the No.2 controller chamber 22. In this way, the pressure control force F to be applied to the secondary pressure chamber (d), irrespective of the size of the No.1 controller chamber 18, is determined by the effective pressure receiving area of the valve 20 and the diaphragm 21 and by the pressure loss of the orifice 25, with the result that the force F can be minimized. |
