GB2284883A

GB2284883A - Atmospheric gas burner

Info

Publication number: GB2284883A
Application number: GB9324942A
Authority: GB
Inventors: John Poole
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-12-06
Filing date: 1993-12-06
Publication date: 1995-06-21
Anticipated expiration: 2013-12-06
Also published as: GB9324942D0; GB2284883B

Abstract

An atmospheric gas burner comprises a central deflector element 14, at least two inwardly pointing gas jets 12 and a gas supply chamber 4 extending around the deflector element to supply gas to the gas jets. The gas jets are arranged serially along the gas supply chamber. The arrangement of the gas supply chamber around the central element allows a large hole to be created in the centre of the burner, enhancing upward airflow. The mounting of gas jets around the supply chamber allows them to be located remotely from the supporting legs 16 and the number of legs can be minimized, further enhancing airflow to the jets. The jets are in pillars 8 which form supports for a combustion tube 23. <IMAGE>

Description

TITLE: Atmospheric gas burner DESCRIPTION Field of the invention The invention relates to atmospheric gas burners, in particular for catering applications.

Background of the invention Gas burners have long been used for cooking and, for certain applications such as commercial Chinese and tandoori cooking, high temperature burners are required.

One such burner is described in British Patent No.

2219071. A number of hollow legs radiate from a central point and conduct gas from an inlet to inwardly directed gas jets at the ends of the legs. The gas emerging from the jets along the legs is deflected upwards by inclined surfaces mounted on the legs. A combustion tube is mounted on the legs to enclose the region of combustion.

Summary of the invention The invention provides an atmospheric gas burner comprising a central deflector element, at least two inwardly pointing gas jets and a gas supply chamber extending around the deflector element to supply gas to the gas jets. The gas jets are arranged serially along the gas supply chamber.

Preferably, the supply chamber forms a complete circuit with the gas jets spaced around it. The deflector element may have a central hole and be connected to the ring by two or more legs. Such legs are preferably connected to the ring at points located between the gas jets. The preferred number of legs is three. The gas jets may be mounted on pillars formed integrally with a ring containing the gas supply chamber. The pillars may taper along a radial direction towards the jets.

The burner according to the invention has a number of advantages over previously known burners, principally deriving from the arrangement of the gas supply chamber around, rather than within, the central element. This allows a large hole to be created in the centre of the burner, through which air is drawn up to enhance combustion. Whereas the prior art burners required the gas jets to be mounted at the ends of the radiating legs, so that the legs themselves interfered with upward flow of air to the gas jets, the present invention makes it possible to locate the jets at points remote from the legs further enhancing airflow. Where the pillars have a tapering cross-section, airflow to the jets is also improved.

In the prior art, the number of legs had to be equal to the number of gas jets so an increased number of jets led to a diminished airflow and less efficient combustion. In the present invention, the number of jets can be increased without the need for any additional legs so efficiency is maintained. With six jets, the burner of the present invention has been found to be of the order of 25 more efficient than comparable known designs.

The jets themelves can be of various known types and optionally an air intake at the side of the nozzle so that a gas-air mixture is emitted from the jet. The jets may be directed precisely towards the centre of the ring or the emerging gas may be given a tangential component: either by angling each of the jets away from a radial orientation or by mounting deflectors on the ring or the combustion tube to divert emerging gas away from the radial direction.

The small number of legs also increases hygiene because of the reduced surface area to which matter falling onto the burner can become attached.

The burner described here lends itself to economical manufacture because the outer ring, pillars, deflector element and legs can all be formed from cast iron in a single moulding. Thus, comparatively little machining is required.

The Drawings Figure 1 is a plan view of a burner in accordance with the invention; and Figure 2 is a somewhat schematic sectional view, generally along line II-II of Figure 1, illustrating the path of gas through the burner.

Description of a preferred embodiment The burner illustrated in Figures 1 and 2 includes a hollow outer ring 2 containing an annular chamber 4. A gas inlet 6 in an outer wall of the ring 2 allows gas to be supplied to the annular chamber 4. Equally spaced around the ring 2 are six pillars 8, integrally moulded with the ring 2 and projecting from its upper surface.

Each pillar 8 includes a vertical bore 10 intersecting the annular chamber 4.

Near the top of an inwardly facing wall of each pillar 8 is a horizontal bore 11 through the wall, which intersects the vertical bore 10 in the pillar 8. The nozzle of a gas jet 12 is located in each of the horizontal bores 11 so that the six gas jets 12 are all directed towards a common point on the axis of the ring 2. In use, the burner is supplied with gas through the gas inlet 6. The gas then distributes itself evenly around the annular chamber 4, flows up through the vertical bores 10 in the pillars 8 and out through the gas jets 12 towards the centre of the burner, as indicated by the arrows in Figure 2.

In the centre of the burner is a hollow, generally frustoconical deflector member 14, integrally moulded with the ring 2. Three equally spaced legs 16 connect the deflector member 14 to the ring 2 at points located between the gas jets 12. The conical inner surface 18 of the deflector member 14 ends in a circular, central hole 20 at its top. The outer surface of the deflector member 14 comprises six generally flat facets 22. Each facet 22 faces one of the gas jets 12, which is directed towards it, so that, in use, gas emanating from the gas jet 12 is deflected upwards by the facet 22, as shown by the arrows in Figure 2. The upward flow of gas entrains air drawn through the central hole 20 to support combustion of the gas. Air is also drawn up through the spaces between the deflector member 14, the ring 2 and the legs 16.The arrangement of legs 16 between the gas jets 12 ensures that the legs 16 do not obstruct the supply of this air to the emerging gas.

In use, a combustion tube 23, of generally cylindrical shape, rests on the pillars 8 to contain the burning gas and air mixture and to shield the gas jets 12 from falling matter. Air may be drawn into the tube 23 through the gaps between the tube 23, the ring 2 and the pillars 8. The supply of such air to the gas jets is improved by the tapering cross-section of the pillars 8 shown in Figure 1.

The ring 2, pillars 8, legs 16 and deflector element 14 are formed as a single cast iron moulding. The annular chamber 4 is formed during the moulding process as a channel around the lower surface of the ring 2. The annular opening of the channel is subsequently machined and then sealed with an insert 24. This provides an efficient method of manufacturing the burner, in which further machining is only necessary for the formation of the vertical bores 10, the horizontal bores 11 and the gas inlet 6.

The horizontal bores 11 are most conveniently drilled through the entire width of each pillar 8 from the outer surface intersecting the vertical bore 10. The resulting hole in the outer wall of the pillar 8 may be sealed with a plug 26. The plug 26 can be removed to assist with replacement of a gas jet 12, particularly in the case where the gas jet 12 has broken to leave a stub in the horizontal bore 11.

Claims

1. A gas burner comprising a central deflector element, two or more gas jets pointing inwardly towards the deflector element and a gas supply chamber extending at least partially around the deflector element for supplying gas to the gas jets, the gas jets being arranged serially along the gas supply chamber.

2. A gas burner according to claim 1, wherein the gas supply chamber is in the form of a ring about the central deflector element, with the gas jets being spaced around the ring.

3. A gas burner according to claim 1 or claim 2, wherein the deflector element has a hole through its centre.

4. A gas burner according to any preceding claim, wherein the deflector element is connected to the supply chamber by two or more legs.

5. A gas burner according to claim 4, wherein the number of legs is three.

6. A gas burner according to claim 4 or claim 5, wherein the legs are connected to the supply chamber at points located between the gas jets.

7. A gas burner according to any preceding claim, wherein each gas jet is mounted on a pillar formed integrally with the gas supply chamber.

8. A gas burner according to claim 7, wherein each gas jet is mounted on an inward face of the pillar and wherein the cross section of the pillar tapers towards its inward face.

9. A gas burner according to any of claims 1 to 8, wherein each gas jet points inwardly along a line that doe not intersect the axis of the burner, so as to give a circumferential component of motion to gas emerging from the gas jets.

10. A gas burner according to any of claims 1 to 8, wherein the central deflector element or the gas supply chamber includes means for imparting a circumferential component of motion to gas emerging from the gas jets.

11. A gas burner substantially as described herein with reference to the drawings.