| 摘要 |
PURPOSE:To control a gas proportional valve and a burning air fan in response to gas quality, by making a gas supplying pressure constant for all grades of the gas quality. CONSTITUTION:A burner (a) is provided under a heat exchanger (c) through a combustion chamber (b). A gas supply pipe 4 and a prinary air supply pipe 3 pierce through opposing side walls of a casing 1, at the upper surface of which flame holes 2 are provided. The primary air supply pipe 3, whose diameter is larger than that of the pipe 4, is concentrically provided between the opposing side walls. The internal ends of the primary air supply pipe 3 are closed. Thus a mixing chamber 10 is formed. A original solenoid valve (f), a gas burner (g) which makes the secondary pressure constant through the gas quality, and the gas proportional valve (h) are connected to the gas supply pipe 4. The primary air supply pipe 3 and a secondary air supply pipe 9, which is opened to the combustion chamber (b) are connected to a proportional fan (e) through an air flow control valve (d). The proportional valve (h), the proportional fan (e) and the air flow control valve (d) are controlled by a control device (i) with gas grades corresponding to the gas quality. |
