GB1593976A

GB1593976A - Gas burners

Info

Publication number: GB1593976A
Application number: GB4498676A
Authority: GB
Original assignee: Valor Newhome Ltd
Current assignee: Valor Newhome Ltd
Priority date: 1978-01-27
Filing date: 1978-01-27
Publication date: 1981-07-22

Description

(54) IMPROVEMENTS RELATING TO GAS BURNERS (71) We, VALOR NEWHOME LIMITED, a British company, of Riverside House, Corney Road, Chiswick, London W4 2SL, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a burner for use in domestic or industrial gas cooking appliances.

A known gas burner comprises a circular burner head having a series of equi-spaced apart radially outwardly directed flame ports in its outer periphery. In use the flames from adjacent flame ports can merge so that all of the flames together form a ring of fire. With gases having comparatively lowburning velocities, (natural gas, butane etc), there is a tendency for flames to move away from the flame ports, and to hold the flames in the region of the flame ports a retention slot i.e. a ring or groove is provided just underneath the flame ports. A gas/air mixture is supplied to this slot through a restricted passage, thereby issuing at a low velocity, and giving rise to a stable flame, which, in turn stabilises the main flames at the flame ports. The necessity for such stabilising flames reduces the overall efficiency.

When a pan or other cooking container is located over or actually in contact with the burner head it will be appreciated that the ring of flame heats a substantially circular region of the base of the pan, the flames spreading outwards to the edge ole the pan.

However, the centre of this circular region is unheated. This is clearly inefficient as for maximum efficiency the central region should also be heated.

The aim of the present invention is to provide a gas burner which, in use, will heat the region of a pan above the centre of the burner and dispense with the necessity for a flame retention slot, thus improving efficiency over the known gas burner.

According to the present invention there is provided a gas burner comprising a burner head defining an annular gas/air mixing chamber, a series of flame ports being provided in the radially inner wall of the chamber and being adapted to, in use, direct a gas/air mixture inwardly of the burner head and swirl the individual flames together.

In a preferred embodiment of the present invention the burner head comprises generally cylindrical inner and outer walls connected together to form an annular gas/air mixing chamber therebetween, a gas/air mixing tube being connected to the outer wall and communicating with the mixing chamber. In use the burner head is arranged with its longitudinal axis substantially vertical, the mixing tube connecting with the lower region of the burner head and the flame ports being provided in the inner wall towards the top of the burner head. The flame ports are arranged in a ring and adapted so that a flame originating from any one port will be directed around the inner wall of the burner head towards an adjacent port. Thus each flame acts as a retention flame for an adjacent flame, the flames thus being held on their respective ports. Thus the flames are swirled together.By inclining the ports slightly upwards the flames besides being directed around the radially inner wall of the burner head, are also directed slightly upwards so that the flames swirl and form a generally conical flame region i.e. a vortex.

In this manner the whole of the base of a pan or other cooking container located over the burner can be heated.

Preferably the ignition ports are located below the ring of flame ports, a suitably shaped member and an ignition device being located in the cavity defined by the said inner wall of the burner head. The shaped member is arranged above the ignition ports and the ignition device, but belowthe flame ports, an annular gap being present between the edge of the shaped member and the inner wall of the burner head. When the burner is to be lit a gas/air mixture issues from the flame ports and the ignition ports. Activation of the ignition device ignites the gas/air mixture issuing from the ignition ports, the flames passing through the said annular gap and igniting the gas/air mix issuing from some flame ports, the flames from which ignite the gas/air mix issuing from the other flame ports.Alternatively, the ignition device can be arranged at a location remote from the burner, a flash tube ignition system as disclosed in our British Patent Application No. 51772/75 (Serial No. 1570496) connecting the ignition device and the burner. Further, the ignition ports may alternatively be located in the outer wall of the burner, and the gas/air mixture ignited by an ignition device, or flash tube ignition system as already described.

A burner according to the present invention may be used with any desired form of pan support. However, preferably the burner is used with a support comprising a substantially planar base, preferably rectangular, having a central aperture through which the burner, projects.

Alternatively the base may be strictly planar. However, the base preferably has a small incline towards the aperture to allow spillage to run away. Wedge-shaped members integral with the substantially planar base and radially arranged with respect to the aperture, project from the upper surface of the substantially planar base, the upper edges of these members tapering down towards the aperture and providing a support for a pan, which support tends to centralise the pan over the burner.

Preferably the support is made of a temperature resistant non-metallic material.

The support can be made of metal but is preferably moulded out of a temperature resistant non-metallic material e.g. a glass ceramic.

The present invention will now be further described, by way of example, with reference to the drawings accompanying the Provisional Specification, in which: Fig. 1 is a perspective view of a preferred embodiment of a burner constructed according to the present invention, Fig. 2 is a cross-sectional view of the embodiment of Fig. 1; Fig. 3 is a perspective view of a preferred form of pan support for use with the burner of Figs. 1 and 2; and Fig. 4 is a cross-sectional view corresponding to Fig. 2, illustrating the pan support and deflector arrangements.

A preferred embodiment of a burner according to the present invention, is illustrated in Figs. 1 and 2 and comprises a burner head 1 having a generally cylindrical inner wall 2 and a generally cylindrical outer wall 3, the walls 2 and 3 being coaxially arranged with respect to each other and interconnected at 4 and 5 to define an annular gas/air mixing chamber 6. A mixing tube 7 is integrally connected with the lower region of chamber 6 and flame ports 8 are provided in the upper region of the inner wall 2 of the burner head. These flame ports are arranged in a ring, equi-spaced apart from each other, and so constructed to direct a flame originating therefrom both around the inner wall 2 towards an adjacent port and slightly upwards.Thus each flame acts as a retention flame for a flame originating from an adjacent port and the flames merge with each other and swirl to form a vortex of flame in the centre of the burner. By varying such parameters as the angle of the ports, the port configuration, the number of ports and their relative spacing, the volume of the mixing chamber and the diameter of inner wall 2, the configuration of the vortex can be adapted to be as efficient as required, heating the whole of a pan base.

In use gas is introduced into the mixing tube 7 and mixed therein with primary air.

The gas/air mix then swirls around the annular mixing chamber 6 improving the nature of the mix, and issues from flame ports 8. Secondary air passing through the axial bore 9 extending through the burner head, supplements the gas/air mixture as does secondary air passing over the upper edge 4 of the burner head.

As evident from Fig. 2, an ignition device 10 is located in the bore 9 under a conical member 11. Ignition ports 12 are located in the inner wall 2 below the conical member 11 which is itself located beneath the ring of flame ports 8. Thus when the burner is to be ignited gas/air mix is fed to the mixing chamber 6 and issues from the ignition ports 12 and the flame ports 8. By subsequently activating the ignition device 10 the gas/air mix from the ignition ports 12 which collects under member 11, ignites and a flame or flames therefrom pass upwards between the inner wall 2 and the edge of the member 11 to ignite gas/air mix issuing from at least some of the flame ports 8. The gas/air mix issuing from the remaining flame ports is lit by the already ignited gas/air mix. In an alternative embodiment (not shown) the ignition device is at a location remote from the burner and connected with the ignition ports 12 by a flash tube as described in our copending British Patent Application No.

51772/75 (Serial No. 1570496). Further, conical member 11 can be replaced by a disc-like cover (not illustrated) or a member of any other desired configuration.

The burner of Figs. I and 2 can be used with any suitable pan support. However a preferred pan support is illustrated in Fig. 3.

This support comprises a rectangular substantially planar base 13 having a central aperture 14 with wedge-shaped pan support members 15 integrally connected with the base 13 and radially arranged with respect to the aperture 14. The upper edge 16 of each wedge-shaped member tapers down towards the aperture 14 so that when a pan is supported on these members it is centralised with respect to the aperture 14 i.e., the burner. The base itself also slopes slightly down towards aperture 14 so that any spillage from a pan will run towards the aperture 14 and be collected beneath the support. However, any spillage must not be allowed to run onto the burner located in the aperture 14 as this could result in the blockage of the flame ports.Thus a deflector 17 (see Fig. 4) is located around the burner, the deflector having a central aperture 18 which fits over the burner and a radially outwardly extending surface 19 which is inclined downwards away from the aperture 18. Spillage thus drops through aperture 14 onto surface 19 and is deflected away from the burner. In an alternative embodiment (not illustrated) the deflector is in the form of a lip around aperture 14, integral with the pan support, apertures allowing spillage to drop between the lip and the inclined surface of the base.

Alternatively the base 13 can be strictly planar. However this would not provide for the removal of spillage. The pan support is integrally moulded from a temperature resistant non-metallic meterial e.g. a glass ceramic. However, alternatively it can be made of a suitable metal.

Further, whilst the pan support described hereabove has a rectangular base 13, the base can alternatively be of any desired configuration e.g. circular, the main criterion being the arrangement of the wedge-shaped members around the burner aperture with their respective upper support edges tapering down towards the burner aperture.

Our copending Application No. 2158/80 (Serial No. 1593977) describes and claims a pan support for a gas burner comprising a base having at least one aperture therein through which, in use, flames from the gas burner can project, wedge-shaped members being integrally connected with the upper surface of the base and radially arranged with respect to the or each aperture, the wedge-shaped members tapering down towards the or each aperture.

WHAT WE CLAIM IS: 1. A gas burner comprising a burner head defining an annular gas/air mixing chamber, a series of flame ports being provided in the radially inner wall of the chamber and being adapted to, in use, direct a gas/air mixture inwardly of the burner head and to swirl the individual flames together.

2. A gas burner as claimed in claim 1, in which the burner head comprises generally cylindrical inner and outer walls connected together to form the annular gas/air mxiing chamber, a gas/air mixing tube communicating with the mixing chamber.

3. A gas burner as claimed in claim 2, in which, in use, the central axis of the annular mixing chamber is arranged substantially vertically, the mixing tube connecting with the lower region of the burner head and the flame ports being provided in the said inner wall towards the top of the burner head.

4. A gas burner as claimed in any one of claims 1 to 3, in which the flame ports are arranged in a ring and adapted so that a flame originating from any one port will be directed towards an adjacent port.

5. A gas burner as claimed in claim 4, in which the flame ports are inclined to the plane of the ring.

6. A gas burner as claimed in claim 4, in which ignition ports are provided in the radially inner wall of the gas/air mixing chamber in a position which with the burner in use, is below the ring of flame ports.

7. A gas burner as claimed in claim 6, in which an ignition device and a shaped member are located in the cavity defined by the said inner wall of the burner head, the shaped member being arranged above the ignition ports and the ignition device but below the flame ports.

8. A gas burner as claimed in claim 7, in which the shaped member is conical and an annular gap is present between the edge of the shaped member and the inner wall of the burner head.

9. A gas burner as claimed in claim 6, in which a shaped member and one end of a flash tube of a flash tube ignition system, are located in the cavity defined by said inner wall of the burner head.

10. A gas burner as claimed in claim 4, in which the ignition ports are provided in a radially outer wall of the gas/air mixing chamber.

11. A gas burner as claimed in any one of the preceding claims, in which the gas burner is mounted within or beneath an aperture in a pan support, the pan support comprising a base with wedge-shaped members integral with the base and projecting from the upper surface thereof, the upper edges of the wedge-shaped members tapering downwards towards the aperture.

12. A gas burner as claimed in claim 11, in which said base is planar.

13. A gas burner as claimed in claim II, in which the base slopes in all directions down towards the aperture.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. preferred pan support is illustrated in Fig. 3. This support comprises a rectangular substantially planar base 13 having a central aperture 14 with wedge-shaped pan support members 15 integrally connected with the base 13 and radially arranged with respect to the aperture 14. The upper edge 16 of each wedge-shaped member tapers down towards the aperture 14 so that when a pan is supported on these members it is centralised with respect to the aperture 14 i.e., the burner. The base itself also slopes slightly down towards aperture 14 so that any spillage from a pan will run towards the aperture 14 and be collected beneath the support. However, any spillage must not be allowed to run onto the burner located in the aperture 14 as this could result in the blockage of the flame ports.Thus a deflector 17 (see Fig. 4) is located around the burner, the deflector having a central aperture 18 which fits over the burner and a radially outwardly extending surface 19 which is inclined downwards away from the aperture 18. Spillage thus drops through aperture 14 onto surface 19 and is deflected away from the burner. In an alternative embodiment (not illustrated) the deflector is in the form of a lip around aperture 14, integral with the pan support, apertures allowing spillage to drop between the lip and the inclined surface of the base. Alternatively the base 13 can be strictly planar. However this would not provide for the removal of spillage. The pan support is integrally moulded from a temperature resistant non-metallic meterial e.g. a glass ceramic. However, alternatively it can be made of a suitable metal. Further, whilst the pan support described hereabove has a rectangular base 13, the base can alternatively be of any desired configuration e.g. circular, the main criterion being the arrangement of the wedge-shaped members around the burner aperture with their respective upper support edges tapering down towards the burner aperture. Our copending Application No. 2158/80 (Serial No. 1593977) describes and claims a pan support for a gas burner comprising a base having at least one aperture therein through which, in use, flames from the gas burner can project, wedge-shaped members being integrally connected with the upper surface of the base and radially arranged with respect to the or each aperture, the wedge-shaped members tapering down towards the or each aperture. WHAT WE CLAIM IS:

1. A gas burner comprising a burner head defining an annular gas/air mixing chamber, a series of flame ports being provided in the radially inner wall of the chamber and being adapted to, in use, direct a gas/air mixture inwardly of the burner head and to swirl the individual flames together.

12. A gas burner as claimed in claim 11, in which said base is planar.

14. A gas burner as claimed in any one of

claims 11 to 13, in which the pan support is moulded out of a temperature resistant nonmetallic material.

15. A gas burner as claimed in claim 14, in which the material is a glass ceramic.

16. A gas burner constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the drawings accompanying the provisional specification.