| 摘要 |
<p>A gas-air mixing valve using a tube. The valve has an internal geometry shape for directing the flow of air and gas, including an air inlet (11), an inlet part from the inlet to a throttle, a gas inlet slot proximate the throttle, and an outlet (29). The inlet part has a first body part (15), preferably of aluminum or other metal, and a replaceable molded part (17, 23) normally of plastic. The first body part (15) has an inlet surface (19) centered about a central axis defined by a concave surface having a first circular cross section. The replaceable molded part (17, 23) has a composite surface defined by conical surface having a linear cross section and further defined by a convex surface (21) having a second circular cross section forming the throttle. The replaceable molden outlet part has a conical (25) surface extending from the second circular cross section to a second convex surface (27) at the outlet (29). The throttle has a radius with respect to the central axis of the valve defined by the relationship between the desired air flow and radius for a particular pressure drop. The gas slot has a thickness with respect to the desired gas flow defined by the relationship between the desired gas flow and gas slot for a particular pressure drop. Both relationships are computer simulatedusing parameters of the system for which the valve is intended to be used.</p> |
