GB2260806A

GB2260806A - Gas burner with associated distributor

Info

Publication number: GB2260806A
Application number: GB9222239A
Authority: GB
Inventors: Peter Bellis
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-10-22
Filing date: 1992-10-22
Publication date: 1993-04-28
Also published as: GB9222239D0

Abstract

A gas inlet or injector nozzle 18 for a gas burner 10, such as a living flame gas fire, has a piece of woven wire cloth 20 positioned in front of the nozzle in order to disturb the flow of gas from the nozzle. The wire member may be in the mouth of the nozzle being held in place by a ceramic tip (110) Fig 2 (not shown). In Fig 1 the wire cloth is in the form of a mesh preferably 2 mm from the nozzle. The mesh may be expanded metal having 40-50% free area. <IMAGE>

Description

Title: Improvements in and relating to gas burners DESCRIPTION This invention concerns improvements in and relating to gas burners.

Gas burners of the type used in some so-called "living flame" gas fires and decorative fuel effect gas fires comprise a gas inlet at the entry to one end of a tube, which tube has a series of holes along its length from which flames emerge. Primary air for combustion enters the tube around the gas inlet where the gas and air mix. Secondary air for complete combustion is that which is burnt around the flames. The resultant flames tend to blue in colour and combustion is relatively noisy.

For such gas fires with say a simulated coal fuel a yellow flame is desirable as that has a warmer appearance and is more reminiscent of a real coal fire.

Also, lower noise output from the fire is desirable.

It is an object of this invention to provide a gas inlet for a burner that may be used in "living flame" and decorative fuel effect gas fires to produce one or both of the above desired effects.

It has now been surprisingly found that disturbing gas flow into the burner may produce one or both of the above desired effects According to the invention there is provided a gas inlet or injector for a gas burner having means for disturbing gas flow associated closely with a nozzle for the inlet or injector.

In one preferred embodiment means for disturbing gas flow is positioned in front of the nozzle. In another preferred embodiment means for disturbing gas flow is positioned within the nozzle. In yet another preferred embodiment means for disturbing gas flow is positioned in front of the nozzle and within the nozzle.

The means for disturbing gas flow may be any gas permeable barrier having restricted passage therethrough for the gas. For example, various types of mesh, such as woven wire cloth, of expanded metal or of perforated metal, may be used. Possibly one or more layers of mesh may be positioned in front of the gas nozzle(s) It may even be possible to provide a mesh cover for the or each gas nozzle. Preferably the distance between a nozzle exit and the mesh layer(s) is less than 5mm, especiaLLy less than 2mm The mesh layer(s) may even be touching the nozzle exit.

Alternatively, especially where the nozzle has a ceramic tip, the mesh may be positioned within the nozzle and especially behind and preferably touching the rear face of the ceramic tip.

In addition to the mesh within the nozzle, especially touching the ceramic tip, mesh may also be provided in front of and preferably touching the nozzle exit, eg. the ceramic tip thereof.

It is believed that the more layers of mesh or the like provided in front of the nozzle the yellower the flame will become.

It is further believed that the desired effects are enhanced the more holes there are in the mesh.

Also, the gas being burnt may affect the choice of mesh, Typically for mesh to be positioned in front of a gas inlet nozzle 40 mesh woven wire cloth is suitable for the propane gas burners but it may be that 30 to 50 mesh woven wire cloth may be suitable. For natural gas 50 to 70, preferably 60 mesh woven wire cloth may be suitable.

For mesh or the like to be positioned within the nozzle, such as directly behind a ceramic tip thereof, a finer mesh may be more suitable than would be used for in front of the nozzle. Typically an expanded metal layer having from 35% to 60%, preferably 40% to 50% especially 46% of free area may be suitable. For a mesh layer a mesh size of from 300-500 mesh may be suitable.

When a combination of mesh/expanded metal is provided in front of and behind a nozzle tip, for use with natural gas the front mesh is preferably of from 20 to 40 especially 30 mesh size and the rear mesh is preferably from 300-500 mesh size. For propane gas, the front mesh preferably is upto 20 mesh size and for the rear expanded metal with upto 46% free area is preferably used.

The present invention is believed to be applicable both to natural gas burners and to propane gas burners as well as a to single and multi-injector gas burners.

It is believed that using finer meshes in the present invention, especially behind a nozzle tip, may reduce low frequency noise emission from a gas burner whilst less fine meshes, especially in front of a nozzle tip, may reduce high frequency noise emission from a gas burner.

The present invention may also be applicable to gas burners wherever they are used and not just to their use in living flame and decorative fuel effect gas fires but also, for example, in radiant gas fires.

The invention will now be further described by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates one embodiment of the invention; and Figure 2 illustrates another embodiment of the invention.

Referring to Figure 1 of the accompanying drawings1 a gas burner 10, such as of the type used in a living flame or decorative fuel effect gas fire, comprises a tube 12 having a series of apertures 14 along its upper surface, from which flames emerge during gas combustion.

At one end of the tube 12 is an injector nozzle 18 for gas supply. The nozzle 18 is spaced slightly away from the tube end so that air for combustion can enter the tube around the nozzle 18 where mixing of gas and air takes place. Positioned just in front of the nozzle 18, say less than 5mm away, is a sheet of 60 mesh woven wire cloth 20 for natural gas or 40 mesh for propane. Alternatively two or more such layers may be provided.

The mesh 20 disturbs the flow of gas as it passes through the mesh and this results in quieter burning and also softening and yellowing of the resultant flames Turning to Figure 2 of the accompanying drawings a gas burner 100, such as of the type used in a living flame or decorative fuel effect gas fire, comprises a tube 102 having a series of apertures 104 along its upper surface from which flames emerge during gas combustion.

At one end of the tube 102 is an injector nozzle 108 for gas supply. The nozzle 108 is spaced slightly away from the tube end so that air for combustion can enter the tube around the nozzle 108 where mixing of gas and air takes place.

The nozzle 108 has a ceramic tip 110 in a rebate at its end. The ceramic tip 110 has a single hole or a plurality of apertures 112 therethrough. Behind the ceramic tip and touching same is a disc 114 of expanded metal mesh typically having about 46% full area.

Alternatively, a mesh disc of mesh size 300-500 may be used instead. The disc 114 of metal mesh, it is believed, disturbs the gas flow through the nozzle, which results in quieter burning.

It is possible to modify the embodiment of Figure 2 by adding a mesh disc or cover to fit in front of and touching the ceramic tip 110. Such a mesh for a natural gas burner may have a mesh size of about 30 but for a propane gas burner may have a mesh size upto 20.

Claims

1. A gas inlet or injector for a gas burner having means for disturbing gas flow associated closely with a nozzle of the inlet or injector.

2. A gas inlet or injector as claimed in claim 1, wherein the means for disturbing gas flow is positioned in front of the nozzle.

3. A gas inlet or injector as claimed in claim 1, wherein the means for disturbing gas flow is positioned within the nozzle.

4. A gas inlet or injector as claimed in claim 1, wherein the means for disturbing gas flow is positioned in front and within the nozzle.

5. A gas inlet or injector as claimed in any one of claims 1 to 4, wherein the means for disturbing gas flow is a gas permeable barrier having restricted passage therethrough for the gas.

6. A gas inlet or injector as claimed in claim 5, wherein the means for disturbing gas flow comprises a mesh.

7. A gas inlet or injector as claimed in claim 5, wherein the mesh is of woven wire cloth.

8. A gas inlet or injector as claimed in claim 5, wherein the mesh is an expanded metal mesh.

9 A gas inlet or injector as claimed in claim 5, wherein the mesh is of perforated metal

10. A gas inlet or injector as claimed in any one of claims 6 to 9, wherein one or more layers of mesh are positioned in front of the nozzle.

11. A gas inlet or injector as claimed in any one of claims 6 to 9, wherein the mesh is in the form of a cover for the nozzle.

12. A gas inlet or injector as claimed in any one of claims 6 to 11, wherein the distance between the nozzle exit and the mesh is less than 5mm.

13. A gas inlet or injector as claimed in claim 12, wherein the distance between the nozzle exit and the mesh is less than 2mmu

14. A gas inlet or injector as claimed in claim 13, wherein the mesh layer or layers are touching the nozzle exit.

15. A gas inlet or injector as claimed in claim 3, wherein means for disturbing gas flow is a mesh and positioned within the nozzle.

16. A gas inlet or injector as claimed in claim 15, wherein the nozzle has a ceramic tip and the mesh is positioned touching the rear of the tip.

17. A gas inlet or injector as claimed in claim 16 further comprising a mesh layer or cover in front of the nozzle.

18. A gas inlet or injector as claimed in any one of claims 6 to 17, wherein the mesh is 30 to 50 mesh woven wire cloth.

19. A gas inlet or injector as claimed in claim 18, wherein the mesh is 40 mesh woven wire cloth.

20. A gas inlet or injector as claimed in any one of claims 6 to 17, wherein the mesh is 50 to 70 mesh woven wire cloth.

21. A gas inlet or injector as claimed in claim 20, wherein the mesh is 60 mesh woven wire cloth

22. A gas inlet or injector as claimed in 15, 16 or 17, wherein the mesh is of expanded metal having from 35 to 658 free area.

23. A gas inlet or injector as claimed in claim 22, wherein the mesh is of expanded metal having from 40 to 50% free area.

24. A gas inlet or injector as claimed in claim 15, 16 or 17, wherein a woven wire cloth mesh is used having a size of 300-500 mesh.

25. A gas inlet or injector as claimed in claim 17 with claims 22 or 23, wherein the mesh in front of the nozzle has a size of from 20 to 40 mesh.

26. A gas inlet or injector substantially as hereinbefore described with reference to and as illustrated in Figure 1 or Figure 2 of the accompanying drawings.