초록 ▼

A variable orifice gas modulating valve for use with an atmospheric Bunsen-type burner is disclosed. The variable orifice valve discharges a jet of fuel directly into the burner mixing tube and modulates the gas flow to the burner by changing the cross-sectional area of the gas jet. This is accompli

A variable orifice gas modulating valve for use with an atmospheric Bunsen-type burner is disclosed. The variable orifice valve discharges a jet of fuel directly into the burner mixing tube and modulates the gas flow to the burner by changing the cross-sectional area of the gas jet. This is accomplished by a thin moveable sheet interposed between a valve body and a cap, through which pass the upstream and downstream portions of a short gas discharge passageway. The sheet has a hole which is positioned relative to the axis of the gas discharge passageway so as to produce a discharge orifice of variable size. The gas jet has the same velocity at all inputs, and flow rate variation is manifested by variation in the jet cross-sectional flow area. This contrasts with the conventional method for gas flow modulation for atmospheric burners wherein the gas jet issues from a fixed orifice and the gas pressure ahead of this orifice is modulated such that variable flow rate is manifested in a gas jet of constant cross-sectional flow area and variable velocity. These two methods of gas flow modulation result in quite different flame characteristics as the burner is turned down, and the variable orifice valve produces superior combustion characteristics at low input. The variable orifice gas valve also has the advantages of mechanical simplicity and linearity of heat input versus valve setting.

대표청구항 ▼

An automatic gas modulating valve for regulating the flow of gaseous fuel from a fuel source to a gas burner, comprising a first valve body member having a first generally planar slide surface and a gas inlet opening communicatively connected to a gas flow conduit extending through the first valve b

An automatic gas modulating valve for regulating the flow of gaseous fuel from a fuel source to a gas burner, comprising a first valve body member having a first generally planar slide surface and a gas inlet opening communicatively connected to a gas flow conduit extending through the first valve body member and terminating in an inlet port formed in the first planar slide surface; a second valve body member fixed to the first valve body member and including a second generally planar slide surface disposed parallel to and spaced from the first planar slide surface of the first valve body member so as to define a relatively thin planar slide cavity between the first valve body member and the second valve body member, the sound valve body member having an outlet port formed in the second planar slide surface in coaxial relation to said inlet port so as to form a contiguous gas discharge passageway between the inlet port of the first valve body member and the outlet port of the second valve body member; a moveable slide sheet which is slightly thinner than the width of said thin planar slide cavity, having an opening formed therein, and sandwiched within said thin planar slide cavity, said slide sheet being moveable back and forth within the planar slide cavity, the opening of the slide sheet being interposed between the inlet and outlet ports such that the sliding motion of the slide sheet varies the position of the slide sheet opening relative to the inlet and outlet ports so as to form a variable orifice within the gas discharge passageway, whereby the flow of gas from the source to the burner is modulated and controlled by the sliding movement of the slide sheet; means to constrain the movement of the slide sheet between two extreme positions, corresponding to two sizes of said variable orifice, such that the flow of gaseous fuel is constrained to be a rate between a maximum rate and a nonzero minimum rate, whereby a flow of gas less than the minimum rate is not permitted, and a flow of gas greater than the maximum rate is not permitted; sealing means to minimize the leakage of fuel gas from the valve structure to the surroundings; an automatic actuator which is responsive to a control signal and which is associated with the gas modulating valve for positioning the slide sheet within the planar slide cavity at a position between said two extreme positions, whereby automatic modulating control of the gas flow may be effected; and connecting means connected between the automatic actuator and the slide sheet for sliding the slide sheet back and forth in response to the actuation of the actuator.