CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase application of International Patent Application No. PCT/GB2018/052986, filed Oct. 17, 2018, which claims priority to Great Britain Patent Application No. GB1717556.3, filed Oct. 25, 2017, both of which are incorporated by reference herein in their entireties for all purposes.

TECHNICAL FIELD

The present invention relates to apparatus for cooking food by a barbecue grilling method.

BACKGROUND

U.S. Pat. No. 5,676,049 describes a barbecue cooking appliance which provides first and second sources of pressurised air to improve combustion efficiency. GB2511850 describes a similar type of cooking appliance with a combustion mixture inlet assembly for controlling the flow of air and fuel to the burner.

SUMMARY OF THE INVENTION

The present invention provides a cooking apparatus for cooking food by a barbecue grilling method, the apparatus comprising an outer housing, an inner housing received in the outer housing and defining a heating volume, a chamber for pressurised air between the outer housing and the inner housing, means to supply pressurised air into the chamber, a plurality of apertures in the inner housing to allow pressurised air to exit the chamber and enter the heating volume, a least one burner located in the inner housing, means to supply a fuel and air mixture to the burner which is separate from the supply of pressurised air into the chamber, and a cooking surface for supporting food.

In this apparatus, the supply of pressurised air into the chamber is separate from the supply of fuel and air to the burner. Pressurised air entering the heating volume via the apertures in the inner housing tends to pull the flame from the burner out across the base of the inner housing, heating the inner housing to provide an additional source of radiant heat for cooking food. In this way, high temperatures can be achieved to fully vaporise fats and oils from the food, while retaining excellent fuel efficiency.

In one embodiment, the cooking surface may be above the heating volume.

In another embodiment, the cooking apparatus may further comprise a top wall which is above the heating volume and which is connected to the inner housing, wherein the heating volume is enclosed by the inner housing and the top wall; wherein the cooking surface is located within the heating volume.

The means to supply a fuel and air mixture to the burner comprises a variable speed fan and a Venturi valve supplying varying levels of gas.

In this arrangement, the cooking apparatus may further comprise a thermostat for controlling the speed of the variable speed fan.

Preferably, the inner housing may comprise a base and side walls and at least one aperture may be provided towards one end of each side wall and adjacent to a corner where the side wall joins the next side wall. In this way, air flowing through the apertures from the chamber into the heating volume tends to form a vortex air flow which swirls around the heating volume. This helps to pull the flame out across the inner housing utilising the vortex air speed to decrease the relative air pressure compared to the centre burner pressure.

Preferably, the cooking apparatus further comprises a support structure located between the inner housing and the outer housing, configured to support the burner and provide a passage for the supply of the combustible fuel/air mixture to the burner which is separated from the supply of pressurised air to the chamber. The support structure strengthens the apparatus and prevents distortion as parts expand as they heat up.

