Ranges of the conventional type utilized in kitchens for cooking typically have one or more atmospheric burner assemblies that each receive a mixture of pressurized gaseous fuel (such as natural gas, manufactured gas, propane, etc.) and atmospheric air. Most of the air constituent is conventionally introduced into the burner or burners at its atmospheric pressure by induction through an air inlet opening that remains of constant size over a complete range of burner gaseous fuel flow rates. The remaining air is convected to the flame from under the burner in an uncontrolled manner and in great excess to the amount needed. Thus, the ideal ratio of air to gaseous fuel is not maintained uniformly over the burner's range of gaseous fuel flow rates and optimum combustion efficiency is not assured at all operational settings of the burner.
We have discovered that an optimum (maximum) combustion efficiency can be assured over a range of gaseous fuel flow rates by introducing air into the range burners at a constant pressure greater than atmospheric pressure, and simultaneously varying the size of the burner's air inlet opening as a function of gaseous fuel flow rate to provide an ideal air flow over a wide range of combustion rates.