AU2003203464A1 - Patio Heater - Google Patents

Description

AUSTRALIA

Patents Act 1990 STANDARD PATENT: COMPLETE SPECIFICATION PATIO HEATER Background of the Invention The present invention relates to patio heaters. More particularly, although not exclusively, the invention relates to a gas-burning columnar patio heater incorporating a circular or toroidal gas burner for use in heating outdoor areas such as might be found at alfresco restaurants and the like.

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 goers, particularly over an extended period of time.

The above-described heaters are also of low efficiency, as in order to warm the body and legs of the restaurant patrons, the high-mounted radiator must produce more heat and is desirable to warm the patrons' heads and necks.

A better approach would be to provide a distributed heat source of 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.

Objects of the Invention It is an object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.

It is a further object of the present invention to provide an improved patio heater.

It is another object of the present invention to provide a columnar gas-burning heater that radiates the heat efficiently.

It is yet a further object of the present invention to provide a patio heater that can efficiently exploit a circular gas burner to reduce the "footprint" of the heater and thereby monopolise less floor space.

Disclosure of the Invention There is disclosed herein a heater comprising: a flue having an inlet and an outlet, a gas burner delivering heat to an interior of the flue, a safety grate surrounding the flue and spaced therefrom, and a reflector situated outside of the flue near its outlet and configured to reflect heat from the flue and/or outlet through the safety grate to a place of need.

Preferably the flue includes an internal scrub-enhancer forcing gases within the flue to negotiate a tortuous path en route from the inlet to the outlet.

Preferably a movable reflector is situated between the grate and the flue.

Preferably the heater includes a gas control and the movable reflector is situated between an operational position for the gas control and the flue.

Preferably the flue is a vertical pipe, the inlet is at the bottom of the pipe and the outlet is at the top of the pipe.

Preferably the exterior surface of the flue is black.

Preferably the reflector is black.

Preferably the flue comprises a tapered lower portion.

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 cross-sectional elevational view of a heater, Figure 2 is a schematic plan view of the heater of Figure 1, and Figure 3 is a schematic cross-sectional elevational view of a of heater having minor modifications including a tapered lower heat exchanger tube.

Description of the Preferred Embodiments In Figures 1 and 2 of the accompanying drawings there is schematically depicted a heater 10. The heated 10 includes a base 21 upon which there is situated a gas cylinder 20 within a compartment made of steel or a polyethylene blow moulding for example.

The heater 10 might typically be a patio heater having a flue or heat exchanger 11 within which there is situated an exhaust gas scrub-enhancer 12. Scrub-enhancer 12 might be in the form of metallic or ceramic baffles or serpentine structures as shown.

The scrub-enhancer serves to slow the flow of combustion gases upwardly through the heat exchanger to be exhausted at 17. The aim here is to cause sufficient contact between the gases and the flue to result ideally in cool gases escaping at the exhaust 17.

The heat exchanger 11 is in the form of a circular cross-sectioned, vertically oriented pipe. A ring of flame is directed against the inner surface of the pipe by an annular gas burner 13. Gas is not wasted, as might be the case if flames were directed at the centre of the pipe under the scrub enhancer for example.

Gas supply from the gas cylinder 20 to the burner 13 is controlled by a gas-control 18.

A safety grate 14 surrounds the heat exchanger 11. The safety grate serves to prevent people from being burned as might occur by touching the heat exchanger 11. The safety grate also serves to support a reflector 15 above a rain cap 16, which is in turn situated upon the heat exchanger at it's exhaust 17. A movable reflector 19 is situated between the grate 14 and the heat exchanger 11 at a position that will protect a person operating the gas-control 18 from heat radiated by the heat exchanger. The movable reflector might be pivotable, or slidable for convenient positioning. For example, there might be provided upper and lower annular tracks guiding the upper and lower horizontal edges of the movable reflector 19 so as to enable the movable reflector 19 to be repositioned throughout 360 degrees of the heat exchanger 11.

The heat exchanger 11 and the reflector 15 are typically coated with a heat-resistant matt black heat-reflective coating. A further reflective surface 19 at the bottom of the heat exchanger 11 might also be coated with a matt black heat-reflective coating.

In Figure 3 of the accompanying drawings there is pictured a heat exchanger 100 wherein the heat exchanger comprises an upper straight tubular portion 11 a and a lower tapered portion 1ib. The tapered portion 1 lb accommodates a larger toroidal burner 13. The baffles 12' in the upper straight tubular portion 1 Ia under a simple discs affixed to a central support 22. These discs are of the differing diameter and impede and disturb the flow of combustion products so that the scrubbing of the internal surface of the tube 12' is enhancer and therefore more heat is given up.

Efficiency is similar to that achieved by the spiral baffle of Figure 1, but manufacturing costs are reduced. Also, in the embodiments of Figure numeral 3, the conical 16 and inverted cone 15 have been deleted and replaced with a heat baffle and rain cap as depicted.

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 heat exchanger might be triangular, square or rectangular for example. Furthermore, the combustion chamber defined about the burner 13 can incorporate whether-proof air intake vents.

Claims (8)

1. A heater comprising: a flue having an inlet and an outlet, a gas burner delivering heat to an interior of the flue, a safety grate surrounding the flue and spaced therefrom, and a reflector situated outside of the flue near its outlet and configured to reflect heat from the flue and/or outlet through the safety grate to a place of need.

2. The heater of Claim 1 wherein the flue includes an internal scrub-enhancer forcing gases within the flue to negotiate a tortuous path en route from the inlet to the outlet.

3. The heater of Claim 1 including a moveable reflector situated between the grate and the flue.

4. The heater of Claim 3 further including a gas control and wherein the movable reflector is situated between an operational position for the gas control and the flue.

The heater of Claim 1 wherein the flue is a vertical pipe, the inlet is at the bottom of the pipe and the outlet is at the top of the pipe.

6. The heater of Claim 1 wherein the exterior surface of the flue is black.

7. The heater of Claim 1 wherein the reflector is black. 7

8. The heat exchanger of Claim 1 wherein the flue comprises a tapered lower portion. Dated this 2nd day of April, 2003 Chiaphua Industries Limited Patent Attorneys for the Applicant HALFORD CO.