AU2003203495A1 - Burner with Tangential Gas Inlet - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT BURNER WITH TANGENTIAL GAS INLET Background of the Invention The present invention relates to burners with a tangential gas inlet. More particularly, although not exclusively, the invention relates to a circular or toroidal burner for use in a heating appliance, such as, but not limited to patio heaters.

Patio heaters, often used at outdoor restaurants, include a post at the top of which there is situated a gas-burning radiator. These radiate heat primarily downwardly toward restaurant patrons seated at the restaurant's tables alongside which the heaters are situated. This localised radiation source can be uncomfortable for the restaurant's patrons, particularly over a period of time. A better approach would be to provide a more even heat radiation from the post itself and to this end, an efficient low-mounted gas burner might be provided to heat the inside of a tubular heat exchanger.

Such a gas burner might also have application in domestic or commercial water heaters for example.

Known toroidal gas burners as used in water heaters and cook-tops for example have a radially extending gas inlet. This not only increases the "footprint" of the burner itself, but also hinders the flow of gas into the annular space beneath the burning ports. Also, where the inlet extends radially from the burner, the gas line attached thereto further increases the required space as the gas line must be bent or curved back (or otherwise contorted to result in wasted space) for connection to a gas-flow control device that might be mounted on the exterior of the appliance. Furthermore, the gas must turn sharply after having been injected into the annular space via the inlet.

The burner should preferably be space-efficient in its construction and have a small footprint so as to enable reduction in the size of the appliance in which it is incorporated.

The arrangement of the gas inlet should be such that a gas supply line can be connected thereto in a space-efficient manner.

A burner should also provide efficient gas distribution to it's burning ports.

Objects of the Invention It is an object of the present invention to provide a space-efficient gas burner for use in a heating appliance.

It is another object of the present invention to provide a gas burner giving efficient gas distribution to its burning ports.

It is a further object of the present invention to provide a toroidal gas burner having a tangential gas inlet to reduce the "footprint" of the burner and reduce space requirements within the appliance for any gas supply line.

Disclosure of the Invention There is disclosed herein a gas burner having a substantially toroidal gas distribution channel distributing gas from an inlet that includes a gas injector delivering gas to the gas distribution channel tangentially.

Preferably, the gas distribution channel distributes the gas to a substantially circular array of burning ports.

Preferably the inlet includes a mixing tube through which gas from the injector passes tangentially to the distribution channel.

Preferably a venturi is situated in the mixing tube so as to accelerate gas injected by the injector into the distribution channel.

The burning ports can be circular apertures.

Alternatively, the burning ports can be radially extending slots.

Alternatively, the burning ports are circumferentially extending slots in a pair of concentric arrays.

Preferably the distribution channel is annular so as to allow secondary combustion air to pass through a centre thereof.

There is further disclosed herein a heating appliance having the above-disclosed gas burner mounted therein so as to direct heat to a heat exchanger.

Preferably, the appliance further includes a gas supply line extending substantially colinearly with and from the gas inlet directly to a gas-flow control valve.

Brief Description of the Drawings Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: Figure 1 is a schematic plan view of a gas burner, Figure 2 is a schematic cross-sectional elevation of a gas distribution channel, Figure 3 is a schematic side elevation of the gas burner of Figure 1, Figure 4 is another schematic side elevation of the gas burner of Figure 1, Figure 5 is a schematic plan view of an alternative gas burner, Figure 6 is a schematic side elevation of the burner of Figure Figure 7 is another schematic side elevation of the gas burner of Figure Figure 8 is a schematic perspective illustration of yet another gas burner, Figure 9 is a schematic parts-exploded perspective illustration of the gas burner of Figure 9, Figure 10 is a schematic close-up detail diagram of the burning ports of the gas burner of Figure 9, and Figure 11 is a schematic cross-sectional elevational view of a patio heater having the gas burner of any one of Figures 1 to 9 therein.

Description of the Preferred Embodiments In Figures 1 to 4 of the accompanying drawings there is schematically depicted a circular or toroidal burner 10. The burner 10 might typically be formed as a steel pressing, but might alternatively be cast or otherwise fabricated. The burner 10 includes a toroidal gas distribution channel 21. Channel 21 is of annular or toroidal form.

The burner 10 includes a mixing tube 14 via which gas enters the distribution channel 21.

The mixing tube includes a venturi or constriction 13 via which gas is accelerated after having been injected by an injector 12.

Gas is delivered to the injector 12 via an inlet 11. A gas-delivery line extending say from a control valve would be attached to the inlet 11. The gas delivery line might extend straight from the inlet 11 to the control valve as a continuous straight tangent. As one could imagine, this would significantly reduce the footprint of the appliance within which the burner is incorporated, as compared to the situation where the mixing tube extends radially from an edge of the burner The burner 10 includes a plurality of burning ports 15 facing upwardly in use.

Optionally, the burner ports may also be located on the sides of the distribution channel.

These are distributed the whole way around the burner to provide a circular array of flames. As shown in Figure 1, the mixing tube 14 extends substantially tangentially from the circular array of burning ports 15. However, it could be said that the mixing tube 14 is offset slightly radially from a true tangential position. In an alternative construction, the mixing tube 40 could be formed as just more than one loop of a coil, with an inlet end positioned beneath the other end portion of the distribution channel. This remote or other end portion would be blocked. In such a construction, the mixing tube 14 would extend linearly from the inlet end of the mixing channel beneath the overlapping end portion.

As shown in Figure 2, the distribution channel might be of hexagonal cross-section.

However, the cross-section might be circular, square, rectangular or any other conveniently manufactured shape.

Figures 5 to 7 depict an alternative burner 20, also of circular/toroidal form and including features similar to those described with reference to Figures 1 to 4. In this embodiment however, the burning ports 15 are in the form of radially extending slots. However, there are many styles of burner porting possible. For example, there might be one or more continuous circular slots extending circumferentially.

Figures 8 and 9 depict a further alternative burner 30. The burner 30 comprises upper and lower pressings 31 and 32 spot welded, riveted, screwed or otherwise connected together to form a gas distribution channel 21. The burner ports 15 are provided in concentric arrays and are in the form of circumferentially elongated slots. The inner array of burner ports is formed between an inner annular steel pressing 34 having outwardly facing port formations thereon and an intermediate annular steel pressing having inner port formations aligned with the outer port formations of the inner metal pressing. The outer array of burner ports is formed between the intermediate annular metal pressing 35 (having outer port formations thereon) and formations 36 on the upper pressing 32. A metal band 37 fits between the inner annular metal pressing 34 and the intermediate annular metal pressing 35, whereas a metal band 38 fits between the intermediate annular metal pressing 35 and the formations 36 on the upper pressing 32.

This detail can be seen in Figure 10 wherein the metal bands divide each port 15 into inner and outer portions.

The gas inlet tube 14 has a straight section followed by a curve section 39 that is tangential to the toroidal burner head.

In the embodiments of Figures 1 to 4, Figures 5 to 7 and Figures 8 and 9, primary air 16 is drawn the into the venturi 17 via suction forces induced as a result of gas injection by the injector 12. Also, in each embodiment, secondary combustion air is provided from both the centre of the burner through the large hole H shown in the plan view of Figures 1 and 5) and the area radially outside of the burner.

Figure 11 depicts a typical installation of a burner 10, 20 or 30. This diagram shows a patio heater having a heat exchanger 17 within which there is situated an exhaust gas scrub enhancer 19. The heat exchanger is in the form of a circular cross-sectioned, vertically oriented pipe. It might be desired to direct a ring of flame against the inner surface of the heat exchanger, without wasting flame up through the centre of the heat exchanger.

The gas burners described above are particularly suited to such an application, because a patio heater should not take up too much floor space, particularly in a small outdoor restaurant. The compact heat exchanger of small footprint (with reduced space requirements for the gas-delivery pipe) resulting from the tangential arrangement of the gas inlet and venturi is eminently suitable to such an application.

It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, instead of being circular, the burner might be oval shaped. Also, in a gas cook-top arrangement for example, the burner might be complemented by a centrally-mounted 7 burner enabling a broad spread of flame-control and this might be particularly suited to cooking with a wok.

Claims (9)

1. A gas burner having a substantially toroidal gas distribution channel distributing gas from an inlet that includes a gas injector delivering gas to the gas distribution channel tangentially.

2. The gas burner of Claim 1, wherein the gas distribution channel includes a substantially circular array of burning ports.

3. The gas burner of Claim 1, wherein the inlet includes a mixing tube through which gas from the injector passes tangentially to the distribution channel.

4. The gas burner of Claim 1 further including a venturi situated in the mixing tube and arranged to accelerate gas injected by the injector into the distribution channel.

The gas burner of Claim 2, wherein the burning ports are circular apertures.

6. The gas burner of Claim 2, wherein the burning ports are radially extending slots.

7. The gas burner of Claim 2, wherein the burning ports are circumferentially extending slots in a pair of concentric arrays.

8. The gas burner of Claim 1, wherein the distribution channel is annular so as to allow secondary combustion air to pass through a centre thereof.

9. A heating appliance having the gas burner of Claim 1 mounted therein so as to direct heat to a heat exchanger. 9 The heating appliance of Claim 9 further including a gas supply line extending substantially co-linearly with and from the gas inlet directly to a gas-flow control valve. Dated this 4th day of April, 2003 Chiaphua Industries Limited Patent Attorneys for the Applicant Halford Co.