| 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, an inlet part from the inlet to a throttle, a gas inlet slot proximate the throttle, and an outlet. The inlet part has a first body part, preferably of aluminum or other metal, and a replaceable molded part normally of plastic. The first body part has an inlet surface centered about a central axis defined by a concave surface having a first circular cross section. The replaceable molden part has a composite surface defined by conical surface defined by conical surface having a linear cross section and further defined by a convex surface having a second circular cross section forming the throttle. The replaceable molden outlet part has a conical surface extending from the second circular cross section to a second convex surface at the outlet. 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 simulated using parameters of the system for which the valve is intended to be used.</p> |
