GB2135767A

GB2135767A - Simulated solid fuel gas fires

Info

Publication number: GB2135767A
Application number: GB08304896A
Authority: GB
Inventors: David James Izzard
Original assignee: MELDA ENTERPRISES
Current assignee: MELDA ENTERPRISES
Priority date: 1983-02-19
Filing date: 1983-02-19
Publication date: 1984-09-05
Also published as: GB8304896D0; GB2135767B

Abstract

To improve the efficiency of a simulated solid fuel gas fires, there is provided between the bed 12 and solid fuel elements 18 thereof, cavity means 22 with at least an upper surface 24 that is perforate, so constructed and arranged that air will be drawn therein, below the said surface 24 the air can mix with gas and the mixture start to combust and the combustion can continue through and above the said surface 24. The cavity means are preferably of non-metallic refractory material, perforate throughout, comprising a plurality of separate elements each of ovate form and in the form of a hollow skin, inserted loose into the fire and arranged in a heap, while being open to the back of the fire to draw in air therefrom. An alternative embodiment utilises an air and gas guide element as disclosed in co-pending Patent Application 8304341 interposed between the bed 12 and cavity means 22. <IMAGE>

Description

SPECIFICATION Gas fires The invention relates to gas fires which simulate the effect of a solid fuel fire.

Such simulated solid fuel effect gas fires are known comprising an open-topped tray, a bed of refractory previous material within the tray, gas inlet means to supply gaseous fuel to the bed, and a body of refractory simulated solid fuel elements above the bed, with spaces between the elements to allow gaseous fuel from the bed to penetrate between the elements. These fires (hereinafter referred to as a fire of the type defined") are to some degree inefficient, mainly because the gas has to burn with a luminous flame in order to simulate the flames of a solid fuel fire.Attempts to supply air at particular places in the body of simulated solid fuel elements in order to change the manner of combustion of the gaseous fuel at those places and hence change the colour of the flame there in order to produce a more realistic effect have done little to improve the overall efficiency of such a fire, for example, because there are allowed to remain substantial areas of said body substantially with no improved air supply. Attempts have been made by the present inventor to mix air with the gaseous fuel within the gas inlet means but, when sufficient air has been intermixed with the gaseous fuel to improve the efficiency of combustion substantially, there has been an overall reduction in the luminosity of the flames which seriously detracts from the realism of the effect.

The invention consists in a fire of the type defined having, between the bed and solid fuel elements thereof, cavity means with at least an upper surface that is perforate, so constructed and arranged that air will be drawn therein, below the said surface the air can mix with gas and the mixture start to combust and the combustion can continue through and above the said surface. By allowing air to be drawn into the cavity means and starting the combusion process there, much improved efficiency of combustion is obtained.

The cavity means preferably comprises nonmetallic refractory material, such as a gas radiant, which of itself and in co-operation with the lower surfaces of the simulated solid fuel elements there-above produces reverberation of heat, the so-called "furnace effect", which raises the temperature of combustion above what it would be without the cavity means and in fact can produce an almost completely non-luminous flame with very high efficiency of combustion, by which is meant reduction of carbon monoxide, compiete combustion of the gas and a higher temperature of combustion. This produces greater heat output and better efficiency of burning of the gas and, at the same time, has been found to draw luminous flames from the edges of the fire towards the centre to retain a realistic effect.

The cavity means are preferably perforate throughout, which allows better throughflow of air, for which reason the cavity means preferably comprise at least one element of ovate form and preferably in the form of a hollow skin. For convenience of manufacture, the cavity means are inserted loose in a fire of the type defined. For improved efficiency and to reduce the number of simulated solid fuel elements, the cavity means may comprise a plurality of separate elements, preferably arranged in a heap. While the air may be drawn in from the sides of the fire, the fire generally has a better appearance if the cavity means are open to the back of the fire to draw in air therefrom.

A particularly efficient arrangement is produced if the cavity means are located on a guide element constructed and/or arranged as claimed and/or described in our co-pending Patent Application 8304341 lodged on 1 6 February 1 983. For the purposes of des cribing and claiming such an arrangement, the whole of the text, claims and drawings of the said Patent Application are hereby imported into the present description.

Reference will now be made by way of example to the accompanying drawings, in which: Figure 1 is a diagrammatic side section through a fire embodying the invention; Figure 2 is a diagrammatic side section through a fire according to a second embodiment of the invention comprising a guide element disclosed in the said Patent Application; Figure 3 is a top plan view of a cavity means element used in the embodiments of Figs. 1 and 2; and Figure 4 is a side view of the element shown in Fig. 3.

Referring to the drawings, a fire of the type defined comprises an open-topped tray 10, a bed 1 2 of refractory pervious material within the tray 10, gas inlet means 14 to supply gaseous fuel to the bed, and a body 1 6 of refractory simulated solid fuel elements 1 8 above the bed, with spaces 20 between the elements 1 8 to allow gaseous fuel from the bed 10 to penetrate between the elements 18. The fire has, between the bed 10 and solid fuel elements 18 thereof, cavity means 22 with at least an upper surface 24 that is perforate, so constructed and. arranged that air will be drawn therein, below ;t.he said surface 24 the air can mix with gas and the mixture start to combust and the combustion can continue through and above the said surface 24.The cavity means 22 comprise non-metallic refactory material which may be china clay or any suitable alumina-silicate. As seen in Figs. 3 and 4, the cavity means are perforate throughout, having holes 26 throughout their upper and lower surfaces 24 and 28 respectively. As also seen in Fig. 3 and 4, the cavity means in this embodiment comprise at least one element of ovate form and in the form of a hollow skin. As seen in Figs. 1 and 2, the cavity means 22 are inserted loose in the fire just as the simulated solid fuel elements 1 8.

The cavity means comprise a plurality of separate elements 30 and each is a gas radiant some 7 cms. long and some 4.5 cms. wide and high and made in the form of a perforate skin varying in thickness from 0.5 to 1 cm,.

and having mesh (i.e. netlike) form, as shown in Figs. 3 and 4. As seen in Fig. 1, the separate elements 30 are arranged in a heap to provide the cavity means 22 which are open to the back of the fire to draw in air therefrom. As seen in Fig. 2, the lowest layer of elements 30 is replaced by a guide element 32 which act as, and for the purposes, described in the said Patent Application, except that the gas and air are supplied separately through guide element 32 to the cavity means elements 30 and hence to the spaces 20 between fuel elements 1 8 rather than directly to spaces 20 between fuel elements 1 8. In the Fig. 1 embodiment, for a tray 10 that is 30 cms.X 30 cms., there be used a heap of 1 5 to 20 elements 30 of the size mentioned above, arranged with perhaps three elements 30 from the back towards the front of the tray 10, going up in perhaps three diminishing layers, while in the Fig. 2 embodiment for a similar tray, there might be some 10 to 1 5 elements 30 arranged in one less layer. In a particular trial, using elements 30 able to withstand 1100 C, the temperature just below the solid fuel increased from about 800"C towards 1000 C.

In an alternative embodiment (not shown), gas radiant elements of cylindrical form about 3 cms. in diameter and 25 cms. long but otherwise similar in form and material to the elements 30 described above, may be used by laying them with their long axis from the back towards the front of the fire, 3 or 4 layers high.

Alternatively, with ovate or cylindrical elements, or indeed with any other cavity means, the fire can be arranged (not shown) with the cavity means open to the side of the fire to draw in air therefrom.

While the preferred form of elements 30 is as a hollow skin, they could alternatively be formed as perforated solids and, indeed could be formed out of non-metallic refractory material but of wire mesh squashed up loosely into the form of a ball or other suitable shape, but the furnace effect would not then be obtained so well.

In the embodiments described, extra air is supplied to all of the spaces between the solid fuel elements.

Claims

1. A fire of the type defined having, between the bed and solid fuel elements thereof, cavity means with at least an upper surface that is perforate, so constructed and arranged that air will be drawn therein, below the said surface the air can mix with gas and the mixture start to combust and the combustion can continue through and above the said surface.

2. A fire as claimed in Claim 1, in which the cavity means comprises non-metallic refractory material.

3. A fire as claimed in Claim 1 or 2, in which the cavity means are perforate throughout.

4. A fire as claimed in any preceding claim, in which the cavity means comprise at least one element of ovate form.

5. A fire as claimed in any preceding claim, in which the cavity means comprise at least one element in the form of a hollow skin.

6. A fire as claimed in any preceding claim, in which the cavity means are inserted loose.

7. A fire as claimed in any preceding claim, in which the cavity means comprise a plurality of separate elements.

8. A fire as claimed in Claim 7, in which the separate elements are arranged in a heap.

9. A fire as claimed in any preceding claim, in which the cavity means are open to the back of the fire to draw in air therefrom.

10. A fire as claimed in any preceding claim, in which the cavity means are located on a guide element constructed and/or arranged as claimed and/or described in our Co- pending Patent Application 8304341 lodged on 16 February 1983.

11. A fire of the type defined comprising cavity means and substantially according to any embodiment hereinbefore described.

1 2. A fire substantially according to any embodiment hereinbefore described with reference to and illustrated in the accompanying drawings.