GB2242738A - Simulated solid fuel gas fires - Google Patents

Abstract

A simulated solid fuel gas fire has a plenum chamber 10 with a first cover 12, sealed to the sides 14 of the chamber 10 and itself having first apertures 16 to pass the gas/air fuel upwards, and a refractory second cover 18 above the first cover 12, the second cover 18 having second apertures 20 matching the first apertures. The second cover 18 has an extended portion 40 comprising four stepped portions 44 with at least three distinct front portions 48 one above another that are adapted to be heated by flames of the fire. The extended cover 18 includes air ducts 50 arranged to draw flames back towards the forward-facing portions 48. <IMAGE>

Description

"Simulated Solid Fuel Gas Fires" BACKGROUND TO THE INVENTION This invention relates to gas fires having the effect of fires burning solid fuel, e.g. coals or logs.

It is known to use a refractory material to underlie simulated solid fuel elements of a gas fire.

THE INVENTION According to the invention, there is provided refractory material according to claim 1. The refractory material may be higher at one point than another. Preferably, it slopes up towards the back of the fire. It is particularly useful for it to have a stepped formation.

The material may be stepped with three or more of said portions. These features may be employed as means to aid forward radiation from the fire and/or means to reduce the quantity of simulated solid fuel elements required.

Reference will now be made by way of example to the accompanying drawings, in which: Fig.1 is a vertical section, taken along I-I of Fig.5, of one embodiment of the invention; Fig.2 is a part section corresponding to Fig.1, showing a detail of the Fig.1 embodiment; Figs.3 and 4 correspond to Fig.2 but show details of alternative embodiments; and Fig.5 is a plan view of the Fig.1 embodiment, partly broken away to show further details.

Reference is made to the patent specification of application 2198836 from which the present application is divided out, which discloses the advantages of various features of the embodiments hereinafter described.

Referring to the drawings, a simulated solid fuel gas fire has a plenum chamber 10 with a first cover 12 sealed to the sides 14 of the chamber and itself having first apertures 16 to pass the gas fuel upwards, and a refractory second cover 18 above the first cover 12, the second cover 18 having second apertures 20 matching the first apertures 16 so as to have the effect, in use, of drawing most of the gas fuel through the second aperture 20 and away from the edges 22 of the second cover 18 below the latter, the fire being provided with means 24 (see Fig.2) to prevent light-back into the plenum chamber 10 ("Light-back" is a known term of the art and refers to the action of changing, fromr a state in which a gas fuel passes through an orifice and flames only on the external side of the orifice, the change being the passing of the flame back through the orifice.) The gas fuel is provided by a gas supply pipe 26 and draws air through openings 28 with it into plenum chamber 10, where the air and gas mix. The gas escapes through apertures 16 and 20. When the gas is lighted above apertures 20, member 24 (to be described below) prevents light-back, and the burning of the gas above second cover 18 draws the gas away from the edges 22 of the second cover 18 below the latter, thus tending to prevent unwanted escape of gas from the region of member 24 around the edges rather than the desired escape through its apertures 20. This process is aided by ensuring that the first apertures 16 do not extend to near the edges of first cover 12, as seen in Fig.5.

The means 24 to prevent light-back provide a fine-aperture structure in the region of the first cover 12. As shown in Fig.2, the means comprise a fine-apertured sheet 24 covering the first cover 12.

This sheet may be of fine metal gauze, but is preferably a sheet of metal perforated with round holes in a triangular arrangement as seen in Fig.5, the holes preferably having a diameter of 1.5mm and being spaced 3mm. apart. This sheet 24 may be loosely placed within a rim 30 (to be described below) or may be welded thereto. Alternatively, small portions 32 of sheet material such as sheet 24 just described may be individually welded to first cover 12 to provide each of the first apertures 16 with a fine-apertured structure in the form of a piece of fine-apertured sheet 32 attached to the first cover 12 at each first aperture 16. Alternatively, the first cover 12 may be formed integrally with apertured material 34 in each first aperture 16, e.g. by forming each aperture 16 as a plurality of small perforations in the sheet material of which first cover 12 is formed.In this case, each of the first apertures 16 is in the form of a structure of fine apertures in the first cover 12. The plenum chamber 10 is formed of sheet metal and the first cover 12 is formed likewise, the two members being welded together around their common rim 36. Above this is welded a rim 30 of L-section, which may have welded to it sheet 24 as described above. The upstanding edge of rim 30 serves to locate and mount loosely the second cover 18 in relation to the first cover 12.

The rim 30 may extend upwardly in one or more parts, or all round, as shown in dashed lines in Fig.1, to serve as a retainer for solid fuel elements 38.

The second cover 18 is a ceramic fibre block, e.g. Foseco's "Procal 50" with a hìgh temperature paint as a surface sealant to reduce tendency to break up under heat, which may be, for example, 25mm thick (when the height of sides 14 is 45mm), the block having (as seen in Fig.5) a front breadth of 350mm, a back breadth of 255mm and a depth (back to front) of 135mm. The second apertures 20 are made sufficiently long in an upwards direction-(as seen in Fig.1) to give a substantial directivity to the gas fuel emerging from apertures 20, preferably so that the spread is substantially 30 or less at the point of emergence at the top of aperture 20, or more preferably substantially 15 or less.It is considered that a suitable range of lengths in the upwards direction of the second aperture 20 is substantially 2 to 3 cm.

The second cover lt is higher at one point than another. It slopes up towards the back of the fire. It has a stepped formation.

These features are indicated in the extended portion 40 of second cover 18 as seen in dotted lines in Fig.1. The slope may be very slight, e.g. 1 cm steps, or even only a total of 2 cm by which the back is higher than the front, with the dimensions given above by way of example. It will be readily seen that this will aid forward radiation from the fire. Also, this will provide means to reduce the quantity of simulated solid fuel elements required. Alternatively, for the latter purpose, there may simply be a central upwardly extended portion of cover 18.

Some or all of the simulated solid fuel elements 38 may be replaced by cavity means elements as disclosed under reference 30 in UK patent specification 2135767 of the present inventor and for the purposes disclosed in that specification.

As seen in Figs. 1 and 2, the second apertures 20 have enlarged entry ports at the bottom facing towards the matching first apertures 16 and may be the same size as the latter (Fig.1) or larger than the latter (Fig.2).

In particular features of embodiments of the invention, there is provided refractory material adapted to underlie simulated solid fuel elements of a gas fire and having the following features: (a) being stepped with three or more distinct stepped portions, (b) sloping upwardly with two or more distinct interrupted portions, (c) having multiple distinct front portions, one above another, (d) having multiple distinct forward-facing portions, and (e) having gas fuel duct means, and air duct means arranged to draw flames back towards forwardfacing portions of the material, which portions may be in the form of forwardly directed teeth, which air duct means may have inlet means at the rear of the material. The material may be in a plurality of separate strata, e.g. one to each step in case (a), which may be keyed together. The strata may be separate castings.By way of example, as seen in Fig.1, cover 18 comprises a refractory material which is one or more hard ceramic castings having a rating of at least 1400"C and preferably at least 2000"C. This, having the extended portion 40, underlies simulated solid fuel elements 38 of gas fire 42 and has the following characteristics: (a) it is stepped with more than three distinct stepped portions 44, (b) it slopes upwardly with more than two distinct interrupted portions 46, (c) it has multiple distinct front portions 48, one above another, (d) it has multiple distinct forwardfacing portions 48, and (e) it has gas fuel duct means 20, and air duct means 50 arranged to draw flames back towards forward-facing portions 48 of the material 18, which portions (52, Fig.6) may be in the form of forwardly directed teeth, and which air duct means 50 may have inlet means 54 at the rear of the material 18 (Fig.1). The material may be in a plurality of separate strata (touching at lines 56, Fig.1), e.g.

one to each stepped portion in case (a), keyed together by mating projections and recesses 58, e.g. each stratum being a separate casting. Embodiments including these features need not include the two-cover feature mentioned above.

Reference is made to the disclosure (including claims) of copending patent applications No. 8629586 and 8629561 (Serial No. 2198837 and 2198835 respectively), features of either or both of which can usefully be combined with the present invention and embodiments, in view of which the disclosure thereof is hereby imported into the present specification.

Claims (14)

1. Refractory material adapted to underlie simulated solid fuel elements of a gas fire and having at least three distinct front portions one above another that are adapted to be heated to incandescence.

2. Material as claimed in claim 1, in which said portions are forward-facing.

3. Material as claimed in claim 1 or 2, which slopes upwardly with two or more distinct interrupted portions.

4. Material as claimed in any preceding claim, which is stepped with three or more of said portions.

5. Material as claimed in any preceding claim, having gas fuelr duct means, and air duct means arranged to draw flames back towards forward-facing portions of the material.

6. Material as claimed in claim 5, in which said forward-facing portions are in the form of forwardly directed teeth.

7. Material as claimed in claim 5 or 6, in which the air duct means have inlet means at the rear of the material.

8. Material as claimed in any preceding claim, which is in the form of a plurality of separate strata.

9. Material as claimed in claim 8, in which there is one of said strata to each stepped portion.

10. Material as claimed in claim 8 or 9, in which the separate strata are keyed together.

11. Material as claimed in any preceding claim, in the form of one or more hard ceramic castings.

12. Material as claimed in claim 1 and substantially according to any example hereinbefore described.

13. Material as claimed in claim 1 and substantially according to any example hereinbefore described with reference to and illustrated in the accompanying drawings.

14. A simulated solid fuel effect gas fire comprising refractory material as claimed in any preceding claim.