A number of gas-fired appliances such as barbecues, space heaters, lamps and the like are intended for outdoor use. Such devices may be plumbed directly into a natural gas supply line or alternatively, may be coupled to a replaceable propane tank or cylinder. In either configuration, gaseous fuel is conducted to the burner of the appliance and, at a point just upstream from the burner, is typically premixed with a sub-stoichiometric quantity of combustion air commonly referred to as primary combustion air. The mixture continues on through a conduit to the burner where additional combustion air combines with the mixture to achieve a stochiometric mixture to thereby provide for proper combustion.
Primary combustion air is typically drawn into a fuel stream by a venturi tube device, also commonly referred to as a mixing tube, wherein the flow of gas within the conduit is managed so as to reduce pressure below ambient and thereby cause air to be drawn into the gas stream through an exposed port. The venturi tube must be situated so as not to hinder the flow of fresh combustion air thereto. Similarly, a path for combustion air flow to the burner must also be kept open at all times in order to support complete combustion.
Outdoor type applications are problematic to the extent that gusting wind can extinguish the flame. In addition to the nuisance that is posed by having to repeatedly relight an appliance, a susceptibility to wind gusts is especially problematic in barbecue applications wherein the extinction of the flame may not be immediately apparent, should for example a cover be in place, and a delay in relighting the burner may have an adverse effect on the cooking process.
An improved gas burning apparatus is therefore needed that is less susceptible to wind gusts to thereby render such apparatus more useable during windy conditions. Barbecues for use in boating applications would be particularly well served by such an improvement as they are typically put to use while cantilevered over the side of the boat where they are especially exposed to gusts and are difficult to protect therefrom.