GB2310924A

GB2310924A - Gas fire

Info

Publication number: GB2310924A
Application number: GB9704421A
Authority: GB
Inventors: Mark Andrew Broadbent
Original assignee: Dunsley Heat Ltd
Current assignee: Dunsley Heat Ltd
Priority date: 1996-03-05
Filing date: 1997-03-04
Publication date: 1997-09-10
Also published as: GB9704421D0; GB9604698D0

Description

GAS FIRE This invention relates to a gas fire of the type which seeks to replicate the appearance of a solid fuel fire.

According to a first aspect of the present invention there is provided a solid fuel effect gas fire which has simulated solid fuel "pieces" and a gas burner beneath them, the burner having a row of frontal gas outlet orifices arranged widthwise of the fire, the orifices being so located that the flames therefrom play over frontal portions of the frontal simulated solid fuel "pieces" of the fire, wherein the spacing between the orifices is substantially constant or varies such that in regions corresponding to spaces between the frontal "pieces" the orifices are absent or further apart than in the regions corresponding to the frontal "pieces".

It has been found that when the frontal orifices are so located that the flames therefrom can play over frontal portions of the frontal simulated solid fuel "pieces" of the fire, the front of the fire achieves a realistic solid fuel fire "glow" effect. Depending upon the arrangement of simulated solid fuel "pieces", the frontal orifices may perfectly adequately be evenly spaced within the row, widthwise of the fire. In other, preferred, embodiments, however, the frontal orifices are preferentially arranged in the region of the frontal "pieces", with the spaces between the "pieces" having no orifices, or a lower density of orifices.

The term "primary air" as used hereinafter denotes air which is mixed with gas to form the combustion mixture. The term "secondary air" as used hereinafter denotes air from the atmosphere which mixes with the flames.

We have found that particularly good results are achievable in accordance with the present invention when a baffle strip is present across the front of the fire, the baffle strip being spaced forwardly of the frontal orifices so as to enable the delivery of a stream of secondary air to the flames issuing from the frontal orifices, said stream urging the flames against the frontal portions of the frontal "pieces". Accordingly such a baffle strip is preferably present. Suitably the arrangement is such that the stream of secondary air flows upwardly into the space between the baffle strip and the frontal "pieces" through a gap between the baffle strip and the front upper edge of the burner.

It is preferred that the baffle strip, when present, extends below the front upper edge of the burner to define a passage between the baffle strip and the front of the burner.

It is preferred that the baffle strip, when present, extends above the front upper edge of the burner to screen from view the lower regions of the frontal flames.

Suitably the baffle strip, when present, is arranged generally upright but has an upper edge region inclined towards the frontal "pieces", preferably at an angle in the range 30 to 600 to the vertical, and preferably projecting across 10-50% of the space between the main plane of the strip, and the frontal portions of the frontal "pieces".

Several "pieces" of the fire - for example including the frontal "pieces" - may be formed on a plaque, and/or individual "pieces" may be employed.

In accordance with a second aspect of the invention there is provided a solid fuel effect gas fire which has a heat resisting moulded plaque on the top surface of a gas burner having gas outlet orifices, the plaque having a cavity formed on its under surface, the cavity terminating at least in a front wall and side walls, which front wall and side walls rest on the gas burner, and the plaque having flues extending from the cavity, to the upper surface of the plaque, the flues corresponding in number and location to orifices in the gas burner; wherein secondary air can enter the cavity.

Preferably, secondary air may enter the cavity through an opening at the rear of the plaque.

Preferably, individual simulated solid fuel "pieces" are located on the plaque, in use. Preferably, also, the plaque itself may be moulded with integral "pieces".

Preferably, the flues taper in the upward direction.

Preferably, the plaque extends beyond the rear edge of the burner, to overhang it, and the cavity thereby extends beyond the rear edge of the burner, to provide the inlet to the cavity, for the secondary air.

At least some of the gas outlet orifices of the second aspect, and preferably at least the rearmost ones, are associated with shields to assist flames therefrom from rising within said flues. Whilst shields may be located on the upstream side of the flames, relative to the flow of secondary air, it has surprisingly been found that better results are obtainable when such shields are located on the downstream side of the flames. Such shields may be provided by providing upward projections from the top surface of the burner, or by downward projections from the underside of the plaque.

Preferably, the plaque tapers towards the front so that rear flues are longer than front flues.

Suitably rear orifices of the second aspect are larger in area than front orifices.

Preferably, the first and second aspects of the invention are embodied together in a gas fire. The orifices of the first aspect are distinct from the orifices of the second aspect, the latter orifices being located rearwardly of the former and preferably being larger than the former orifices. The former orifices are suitably of cross sectional area in the range 0.5-5 mm2, preferably 1-2 mm2, whilst the latter orifices are suitably of cross sectional area in the range 20-100 mm2, preferably 40-80 mm2.

Suitably primary air is supplied to the burner and mixed therein with gas, so that a gas/air mixture is supplied to the gas outlet orifices.

The invention will now be further described, by way of example, with reference to the accompanying drawings in which: Fig. 1 shows the upper surface of a gas burner; Fig. 2 is a side sectional view of the burner, on which a moulded plaque is resting; Fig 3. is a plan view of the plaque, on the burner; and; Fig. 4 is a side sectional view of a second embodiment.

The fire illustrated in the drawings is intended to fit in the conventional domestic fire space which narrows towards the rear. Each fire has a framework which is generally not illustrated.

With reference to Fig. 1, the fire comprises a single burner 2, having a flat upper surface 4. The burner has four straight rows of gas outlet orifices, arranged widthwise of the burner. The front row 6 is at the front of the burner, and is a row of small, circular, evenly spaced gas outlet orifice 8, of diameter 1.2 mm. The other three rows are all of larger, circular orifice 10.

The rearmost such row has four orifices of diameter 8 mm.

The next row has five. The central three are of diameter 8 mm, and the outer two are of diameter 7 mm. The next row again has four, of diameter 7 mm. Fig. 2 shows a ceramic heat resistant moulded plaque 12 resting on the burner 2. The burner 2 is fed with an air/gas mixture by a pipe 14, the plaque has a cavity 16 formed in its underside, the plaque having a skirt around its periphery, defining this cavity. The front wall 18 of the skirt and the side walls (not shown) rest on the burner. The rearmost wall 20 does not rest on the burner. In fact, the rear region of the plaque extends beyond the rear edge of the burner, to leave an opening 22 through which secondary air can reach the larger outlet orifices 10.

It will be observed from Fig. 2 that the front of the plaque 12, which front is shaped to simulate solid fuel coals, is adjacent to, but slightly set back from, the front row of outlet orifices 6. The plaque tapers towards its front.

The plaque has a series of flues 28 extending upwardly through it, a respective flue being located above each of the outlet orifices 10, with the flues being longer and wider, towards the rear of the plaque. The flues are generally smooth-sided, and are generally rectangular in horizontal cross-section - see Fig. 3.

They taper in the upward direction. Individual "pieces" are located on top of the plaque but are not shown in the drawings, for clarity.

The outlet orifices 10 of the rearmost row of orifices are shielded from the effect of the air entering the cavity 16 by means of heat resistant deflector shields 26 carried by the burner, to ensure that the respective flames rise within the flues. It has not been found necessary, in this embodiment, to similarly shield the orifices of the two other rows, beneath the plaque, though this can be done if required. In other embodiments such deflectors may be constituted by downward projections from the plaque itself.

Individual solid fuel "pieces" (not shown) simulating pieces of coal are placed in pre-determined positions on the upper surface of the plaque.

Figure 2 shows the flames of the fire immediately after ignition and at a low setting. At higher settings and when the fire is hot, the front row of flames are drawn onto the frontal surfaces of the "pieces" 24, and the other flames extend above the plaque, to play onto and through individual "pieces" resting thereon.

It is found that the provision of a row of outlet orifices positioned so that flames play against the frontal "pieces" of the fire gives the front of the fire a realistic flame effect, in use. It is further found that the use of a plaque of the type described, with flues corresponding in position to the larger outlet orifices, and with outlet orifices shielded if necessary from the incoming secondary air, also provides a realistic flame effect, within the core of the fire.

The fire shown in Fig.4 is similar to that of the first embodiment of Figs. 1 to 3 and the same numerals are used to denote parts which are the same as in the first embodiment. However, there are three important differences. The first difference is that a baffle strip 100 is located across the entire front of the fire, secured at each end to the framework of the fire. The baffle strip 100 extends above the upper front edge 102 of the burner 2 to a height of about one-third of the height of the frontal "pieces" 24. Its upper edge region 104 is inclined inwardly at about 450 from the vertical, towards the frontal flames, and thereby projects across about onethird of the space between the main plane of the strip, and the front portions of the frontal "pieces"; otherwise the baffle strip is planar and in a vertical plane. The strip extends below the upper front edge of the burner 2 to define, between the strip and the frontal face 106 of the burner, a passage 108 of even spacing (12 mm width in this embodiment). In operation, air is drawn into the passage 108, and flows upwardly until it passes the upper front edge 102, which represents the end of the passage 108. It is then in the space between the baffle strip and the frontal "pieces" 24. The supply of secondary air to lowermost regions of the frontal flames itself assists in obtaining a realistic effect. Furthermore, the direction of flow of the secondary air is such that the flames are urged onto the frontal portions of the frontal "pieces", causing the flames to blaze against the "pieces". Also, the strip protects the frontal flames from draughts, and screens their lowermost regions from view. The latter is important because even though the supply of secondary air assists in obtaining a realistic effect, it is unavoidable that the lowermost regions will nevertheless tend to be the least realistic-looking parts of the flames. Fig. 4 shows the frontal flames at their highest, and the bottom one-third to one-half of the flames are then screened from view by the strip. The flames issuing from the larger orifices are shown extending out of the flues and in practical use they will play onto and through the individual "pieces" (not shown) located on top of the plaque.

The second difference relates to the shields used adjacent to the larger outlet orifices. In the embodiment of Fig. 4 the shields 120, of similar size and shape to the shields 26 shown in Fig. 1, are moulded as part of the plaque rather than as separate parts carried by the burner. More significantly they are located just downstream of the orifices of the rearmost row of orifices. It has been found that this gives a cleaner burn, whilst still assisting the flames from rising properly within the respective flues.

The third difference, not apparent in Fig. 4, is that in the linear row of frontal orifices, the density of orifices in front of the frontal "pieces" is higher than that in front of spaces in between. The spacing of orifices in front of the "pieces" is about half of the spacing of orifices in front of the spaces.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAINS

1. A solid fuel effect gas fire which has simulated solid fuel "pieces" and a gas burner beneath them, the burner having a row of frontal gas outlet orifices arranged widthwise of the fire, the orifices being so located that the flames therefrom play over frontal portions of the frontal simulated solid fuel "pieces" of the fire, wherein the spacing between the orifices is substantially constant or varies such that in regions corresponding to spaces between the frontal simulated solid fuel "pieces" the orifices are absent or further apart than in the regions corresponding to the frontal "pieces".

2. A solid fuel effect gas fire as claimed in Claim 1, wherein a baffle strip is present across the front of the fire, the baffle strip being spaced forwardly of the frontal orifices so as to enable the delivery of a stream of secondary air to the frontal flames issuing from the frontal orifices, said stream urging the flames against the frontal portions of the frontal "pieces".

3. A solid fuel effect gas fire as claimed in Claim 2, wherein the arrangement is such that the stream of secondary air flows upwardly into the space between the baffle strip and the frontal "pieces" through a gap between the baffle strip and the front upper edge of the burner.

4. A solid fuel effect gas fire as claimed in Claim 3, wherein the baffle strip extends below the front upper edge of the burner to define a passage between the baffle strip and the front of the burner.

5. A solid fuel effect gas fire as claimed in Claim 3 or 4, wherein the baffle strip extends above the front upper edge of the burner to screen from view the lower regions of the frontal flames.

6. A solid fuel effect gas fire as claimed in Claim 5, wherein the baffle strip is arranged generally upright but with an upper edge region inclined towards the frontal flames.

7. A solid fuel effect gas fire as claimed in any preceding claim, wherein gas outlet orifices are preferentially arranged in the region of the frontal "pieces", with the spaces between the "pieces" having no orifices, or a lower density of orifices.

8. A solid fuel effect gas fire as claimed in any preceding claim, having a plaque on which there is defined a plurality of "pieces".

9. A solid fuel effect gas fire as claimed in Claim 8, which has a heat resisting moulded plaque on the top surface of a gas burner having gas outlet orifices, additional to said frontal orifices, the plaque having a cavity formed on its under surface, the cavity terminating at least in a front wall and side walls, which front wall and side walls rest on the gas burner, and the plaque having flues extending from the cavity, to the upper surface of the plaque, the flues corresponding in number and location to said additional orifices in the gas burner; wherein secondary air is able to enter the cavity.

10. A solid fuel effect gas fire as claimed in Claim 9, wherein shields are provided adjacent to at least some of said additional orifices to assist flames therefrom to rise within said flues.

11. A solid fuel effect gas fire as claimed in Claim 10, wherein said shields are located downstream of the flames, relative to the flow of secondary air.

12. A solid fuel effect gas fire as claimed in any of Claims 9 to 11, wherein the plaque has an opening at the rear of the plaque to permit secondary air to enter the cavity.

13. A solid fuel effect gas fire as claimed in Claim 12, wherein the plaque extends beyond the rear edge of the burner, to overhang it, and the cavity thereby extends beyond the rear edge of the burner, to provide the inlet to the cavity, for the secondary air.

14. A solid fuel effect gas fire as claimed in any of Claims 9 to 13, wherein the flues taper in an upward direction.

15. A solid fuel effect gas fire as claimed in any of Claims 9 to 14, wherein the plaque tapers towards the front so that the rear flues are longer than the front flues.

16. A solid fuel effect gas fire as claimed in any of Claims 9 to 15, wherein said additional orifices are each of cross sectional area in the range 20-100 mm2.

17. A solid fuel effect gas fire as claimed in Claim 16, wherein the said additional orifices are each of cross sectional area in the range 40-80 mm2.

18. A solid fuel effect gas fire as claimed in any preceding claim, wherein the frontal orifices are each of cross sectional area in the range 0.5-5 mm2.

19. A solid fuel effect gas fire as claimed in Claim 16, wherein the frontal orifices are each of cross sectional area in the range 1-2 mm2.

20. A solid fuel effect gas fire as claimed in any preceding claim, wherein primary air is supplied to the burner and mixed therein, so that a gas/air mixture is supplied to the gas outlet orifices.

21. A solid fuel effect gas fire as substantially herein before described with reference to the accompanying drawings.