GB2174189A

GB2174189A - A burner tube for cooking appliances

Info

Publication number: GB2174189A
Application number: GB08510336A
Authority: GB
Inventors: Michael Zannetos
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-04-23
Filing date: 1985-04-23
Publication date: 1986-10-29
Also published as: GB8510336D0

Abstract

The burner tube has an open inlet end 7 into which a jet of combustible gas is directed, the gas jet being passed through a turbulence-inducing insert 10, Fig. 2, provided in the open end of the burner tube, the insert defining one or more constricted orifices which are located inwardly of the open end of the burner tube when the insert is positioned in the tube. <IMAGE>

Description

SPECIFICATION A burner tube for cooking appliances THIS INVENTION concerns improvements in or relating to burner tubes for cooking appliances, such as gas barbecues and particularly kebab grills.

A kebab grill comprises a base in the form of an upwardly open housing made of sheet metal and a grate of metal or ceramics supported above the housing. A line of horizontally extending elongate burner tubes are arranged parallel to one another within the housing beneath the grate for heating food placed on the grate.

Each burner tube is closed at one end and a suitable mixture of air and combustible gas, such as natural gas, is injected into the other or inlet end of the burner tube. A series of burner apertures is formed along the tube and, in use, the gas mixture leaving the tube through these burner apertures is ignited.

To enable ignition of the air/gas mixture leaving the burner apertures and subsequently to provide even combustion along the length of the burner tube, it is necessary to induce turbulance in the gas/air mixture within the burner tube.

Various relatively complex and expensive arrangements have been employed in the past to achieve this effect. For example, in one known arrangement a burner tube with circular cross-section has its inlet end externally threaded for the screw-threaded attachment of a Venturi-type inlet device into which gas is injected axially and into which air is drawn radially through air-inlet ports to provide a turbulent flow of gas/air mixture into the burner tube. Whilst such Venturi-type devices are effective in operation, they are relatively expensive.It is an object of the present invention to provide a simplified and inexpensive burner tube construction for cooking appliances such as kebab grills and to this end the invention provides a burner tube construction for a cooking appliance, in which an inlet jet of combustible gas is directed into an open inlet end of the burner tube so as to entrain air as it enters the burner tube and in which the resulting air/gas mixture flows into the burner tube through a turbulence - inducing insert introduced into the open end of the burner tube and defining one or more constrictions in the cross-section of the burner tube at a location spaced inwardly from the open end of the burner tube.

In one embodiment of a burner tube in accordance with the invention, the insert takes the form of a strip of resilient material bent into a substantially V-shaped configuration and provided in an apex portion thereof with one or more apertures or notches defining constricted orifices through which the air/gas mixture passes and is thereby rendered turbulent.

In order that the invention may be readily understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a burner tube construction embodying the present invention; Figure 2 is an enlarged perspective view of the turbulence -inducing insert removed from the burner tube; Figure 3 is a longitudinal cross section through the burner tube of Fig. 1 on the line Ill - Ill; and Figure 4 is an enlarged transverse cross section through the burner tube on the line IV - IV of Fig. 1.

The drawings illustrate one embodiment of a burner tube construction in accordance with the present invention for use in a gas barbecue, e.g. kebab grill, such construction employing an elongate rectangular burner tube 1 made of steel. One end of the burner tube is closed by an end wall 2 from which projects a threaded stud 3 for use in securing the burner tube 1 in position in the kebab grill. To this end, the stud is passed through an aperture 4 in a bulkhead 5 of the grill base or housing (not otherwise shown) and secured by means of a nut.

Along its length the burner tube 1 is formed on two of its sides with a series of burner apertures 6. The other two side of the square - section tube 1 which are not shown are unapertured.

An open inlet end 7 of the burner tube is, in use, Jocated adjacent a gas inlet nozzle 8 through which a jet of combustible gas, such as natural gas, is directed axially into the open inlet end 7 of the burner tube 1. The combustible gas is supplied to the nozzle 8 via a manually operable control valve (not shown) accessible from the grill housing. The nozzle 8 is located relative to the open inlet end 7 of the burner tube 1 so that the flow combustible gas emerging therefrom entrains a flow of air into the burner tube 1 through the gap between the nozzle 8 and the open end 7 of the burner tube 1.

A turbulence - inducing insert 10 is lodged as a push-fit within the open inlet end of the burner tube 1 and is constituted by a strip of resilient material (e.g. a suitable steel or plastics material) having a width substantially equal to the width of the internal face of each of the flat walls of the burner tube 1. The strip is bent into a substantially V-shaped configuration to form two arms 11 and 12 each terminated by a respective lip 13, 14 which abuts the open end of the burner tube 1 when the device 10 is fully inserted in the burner tube. An apex portion 15 of the device 10 is formed withsharp-edged flow apertures through which gas injected into the open end 7 of the burner tube 1 emerges into the portion of the burner tube 1 downstream of the device 10.In passing through these constricted flow apertures, the gas/air flow is rendered turbulent before it reaches the series of burner apertures 6.

In the illustrated embodiment, the device 10 has a series of three circular apertures 16 arranged symmetrically with respect to the apex of the folded strip, but it is envisaged that other arrangements of apertures could be provided and indeed the apertures could be in the form of notches in the edge of the resilient strip to define suitable constricted flow apertures between the edge of the strip and the internal surface of the burner tube 1. It is also envisaged that various dimensions and arrangements of flow apertures could be provided in different interchangeable devices 10 to provide for operation of the burner tube with different combustible gases.

It will be appreciated that the present invention provides a simple and inexpensive, but nevertheless effective means of imparting turbulence to the flow of gas/air mixture within the burner tube 1.

Claims

1. A burner tube construction for a cooking appliance, in which an inlet jet of combustible gas is directed into an open inlet end of the burner tube so as to entrain air as it enters the burner tube and in which the resulting air/gas mixture flows into the burner tube through a turbulence - inducing insert introduced into the open end of the burner tube and defining one or more constrictions in the cross-section of the burner tube at a location spaced inwardly from the open end of the burner tube.

2. A burner tube construction according to Claim 1, wherein the insert has a substantially V-shaped configuration and is provided in an apex portion thereof with one or more apertures or notches defining constriction orifices through which the air/gas mixture passes and is thereby rendered turbulent.

3. A burner tube construction according to Claim 2, wherein the insert takes the form of a strip of resilient material bent into a substantially V-shaped configuration.

4. A burner tube construction substantially as hereinbefore described with reference to the accompanying drawings.

5. An insert for positioning in a burner tube of a cooking appliance adjacent on open end of the burner to induce turbulence in a combustible gas/air mixture flowing into the open end of the burner, which insert defines one or more constricted orifices which are located inwardly of the open end of the burner tube when the insert is positioned in the tube.

6. An insert according to Claim 5, wherein the insert has a substantially V-shape configuration and is provided in an apex portion thereof with one or more apertures or notches defining the constricted orifices through which the air/gas mixture passes and is thereby rendered turbulent.

7. An insert according to Claim 6, wherein the insert takes the form of a strip of resilient material bent into a substantially V-shaped configuration.

8. A burner tube insert substantially as hereinbefore described with reference to the accompaying drawings.

9. A cooking appliance including a burner tube construction according to any one of claims 1 to 4.

10. A gas barbecue, such as a kebab grill, including a burner tube construction according to any one of claims 1 to 4.

11. Any novel feature or combination of features described herein.