GB2134641A - A solid fuel effect gas fire - Google Patents

Abstract

In a solid fuel effect gas fire of the "sand-burner" kind, at least one wall of a sand-containing tray 11 or 12 is used to define a perforated gas-supplying duct from which the gas escapes to percolate through the sand 14. The duct may conveniently be defined by perforating said one wall, fixing a manifold to it to form a substantially gas-tight enclosure around the perforations and providing the manifold with a gas inlet; or by fixing a perforated sheet to the inside of said one wall to form a substantially gas- tight tunnel with the wall, and providing the tunnel with a gas inlet. Preferably the perforations run substantially parallel with the tray base. The imitation fuel itself may advantageously rest on a grid above the sand, rather than sitting directly on the surface of the sand. <IMAGE>

Description

SPECIFICATION A solid fuel effect gas fire The invention relates to a solid fuel effect gas fire.

Solid fuel effect gas fires are well-known generally. UK Patent Specifications Nos.

1 541 423 (Mitchell), 1 602 904 (Mitchell), 2 081 890A (Features Fires Ltd), and 2 084 31 0A (Mitchell) all show examples of solid fuel effect gas fires of the "sand-burner" kind, i.e. in which gas percolates through a bed of silica sand or like material held in a tray and is ignited at the surface of the sand to play around imitation logs or imitation coal lumps sitting on the bed of sand.

In each of these known arrangements, a perforated gas-supplying tube is embedded in, and surrounded on all sides by, the sand. The tube is an initially separate component which is fitted to the tray during assembly of the fire. If the tube is disturbed during servicing of the fire, or if it has to be removed for attention in its own right, the sand around it is disturbed. This can affect the performance of the fire adversely, and requires the whole of the sand to be emptied from the tray and then redistributed about the tube if the tube is removed altogether and subsequently replaced.

According to the present invention, a solid fuel effect gas fire of the sand-burner kind is characterised by the feature that at least one wall of the tray is used to define a perforated gassupplying duct from which the gas escapes to percolate through the sand. This duct, unlike the tubes of the known arrangements reviewed above, is not surrounded on all sides by the sand; the duct thus defined will not move in the sand during subsequent use of the fire; and the sand need not be disturbed should the duct need servicing or other subsequent attention in its own right.

The duct may conveniently be defined by perforating said one wall, fixing a manifold to it to form a substantially gas-tight enclosure around the perforations, and providing the manifold with a gas inlet.

Alternatively the duct may be defined by fixing a perforated sheet to the inside of said one wall to form a substantially gas-tight tunnel with that wall, and providing the tunnel with a gas inlet.

In the case just outlined, the perforated sheet may conveniently span the angle between a side wall and the base of the tray.

In any arrangement embodying the invention, the perforations may advantageously run substantially parallel with the tray base.

In the known gas fires reviewed at the beginning of this specification, the imitation fuel lumps sit directly on the surface of the sand bed.

Here again, if the fuel is disturbed, or gradually decomposes during use of the fire, the performance of the fire can all too easily be impaired. In another advantageous development of the present invention, the "fuel" rests on a grid above the sand, and so the sand-containing tray is not an open-topped tray but is effectively closed off by the grid.

The grid just mentioned may be a mesh of criss-crossed bars, or it may alternatively consist of a perforated sheet. Whatever its construction, it will of course allow gas and gas-air mixture to reach the imitation fuel from the sand bed, and it will be made of material which sufficiently resists the heat generated around it.

Examples of solid fuel effect gas fires each embodying the invention are shown in the accompanying drawings. They will now be described with reference to those drawings. They are currently the best ways known to the applicant of putting the invention into practice.

In the drawings: Figure 1 shows in sectioned end elevation a first fire embodying the invention; Figure 2 shows the fire of Figure 1 in sectioned plan; and Figures 3, 4, 5 and 6 each show respectively different ways of defining the perforated gassupplying duct in the sand-containing tray of a gas fire embodying the invention.

All the drawings are diagrammatic drawings, but the intended skilled addressee of this specification will readily be able to use them in conjunction with the previously-published UK Patent Specifications referred to above in order to put the present invention into practice.

In Figure 1 , two individual rectangular opentopped trays 11, 12 are carried on bearers 1 3 and are spaced apart so as to run parallel with one another as illustrated in Figure 2. Each tray contains silica sand 14. imitation fuel-effect ceramic lumps 1 5 sit on top of the sand 14 with air gaps in between them. In this particular embodiment, the "fuel" lumps 1 5 span the gap between the two trays, and are piled higher in one tray than in the other.

The tray with the higher pile of imitation lumps of fuel is the back tray of this particular fire when the fire is installed in a domestic fireplace and connected to the gas supply.

A side wall of each tray 14 is perforated at invervals along its length. The perforations are indicated by the reference numeral 1 6. They run in-line along the respective tray wall. Each line of perforations 1 6 is surrounded by a respective elongate rectangular manifold 17, 1 8 which is fixed to the perforated wall of the associated tray to surround the line of perforations 1 6 in a substantially gas-tight manner.

The manifolds 17, 1 8 may be welded, braised or otherwise permanently fixed around the perforations 1 6; or they may be screwed into place. The perforations 1 6 are of relatively small diameter, and are drilled parallel with the base of each tray 1 1, 12.

Each of the manifolds 17, 1 8 is drilled and tapped to provide an inlet for gas flowing through a union 1 9. The gas supplied to this union goes through a tap (not illustrated) which enables gas to be supplied simultaneously to both trays; or to either of the two trays by choice; or, of course, to neither tray when the tap is switched "off". The details of the tap are not an essential feature of the present invention, and can readily be supplied by the skilled reader.

In use, with the gas tap turned "on" and supplying either or both of the trays 11, 12, the fire works in the way familiar from the prior art.

Gas enters each tray through the perforations 1 6 and percolates up through the bed of sand 14 to spread over the surface of the sand, where it is ignited to form flames which then play around the imitation fuel 1 5. The gaps between the individual lumps of fuel create a gas-air mixture in certain randomly-spaced regions of the fuel 15 and this adds to the realism of the fire.

In Figure 3, the gas-supplying duct is defined in similar manner to that of Figure 1 and 2, but the manifold 1 7 is flanged and is screwed removably to the perforated side wall of the tray 11 rather than being permanently braised or welded to it.

This gives access to the perforations 16, should they become blocked, but without having to disturb the sand at all.

In Figure 3, the perforations 1 6 are again drilled parallel to the base of the tray 11.

In Figure 4, a sheet 21 is perforated at intervals along its length, as indicated by numeral 16, and is fixed to the inside of the tray wall to define with that wall a tunnel which is substantially gas-tight apart from the perforations 1 6. A drilled and tapped hole 22 through the side wall provides a gas inlet into the thus-defined tunnel for gas supplied through the union 1 9.

In Figure 5 a sheet 21 is again fixed to the inside of the tray wall to define a tunnel which is substantially gas-tight apart from perforations 1 6 in the sheet. In this case, the tunnel is triangular in cross-section, whereas in Figure 4 it was rectangular. In both cases, the perforated sheet 21 spans the angle between a side wall and the base of the tray.

Here again, the perforations 16 are drilled parallel to the base of the tray. This makes it less likely that sand grains will enter them and block them or part-fill the tunnel itself.

In Figure 5 the gas inlet is not illustrated. It is in fact formed in an end wall of the tunnel, so that the gas flows in parallel with the length of the tunnel rather than at right angles to it as in Figures 1 to4.

In Figure 5 also, the tray is not an open-topped tray but is closed off, after the sand 1 4 has been poured in, by a grid 23. The grid 23 is a perforated sheet of heat-resistant material. The sand 14 fills the whole of the tray up to the underside of the grid 23.

Finally in Figure 6 the gas-supplying duct is defined by perforating the base of the tray and fixing a manifold 1 7 to the underside of the base, with a suitable gas inlet into the manifold. In this particular case, the perforations 1 6 are very small, and the silica sand is relatively coarse-grained, to minimise the risk of the perforations and/or the duct itself becoming choked.

Air-induction means could be provided, so that some parts of the fire burn a mixture of gas and air to give a more realistic overall effect. The prior specifications, referred to, disclose such means.

Claims (10)

1. A solid fuel effect gas fire of the "sandburner" kind, characterised by the feature that at least one wall of the sand-containing tray is used to define a perforated gas-supplying duct from which the gas escapes to percolate through the sand.

2. A gas fire according to Claim 1 and in which the duct is defined by perforating said one wall, fixing a manifold to it to form a substantially gastight enclosure around the perforations, and providing the manifold with a gas inlet.

3. A gas fire according to Claim 1 and in which the duct is defined by fixing a perforated sheet to the inside of said one wall to form a substantially gas-tight tunnel with the wall, and providing the tunnel with a gas inlet.

4. A gas fire according to Claim 3 and in which the perforated sheet spans the angle between a side wall and the base wall of the tray.

5. A gas fire according to any of the previous claims and in which the perforations run substantially parallel with the tray base.

6. A gas fire according to any of the preceding claims and in which the imitation fuel rests on a grid above the sand.

7. A gas fire according to Claim 6 and in which the grid is a mesh of criss-crossed bars.

8. A gas fire according to Claim 6 and in which the grid is a perforated sheet.

9. A gas fire substantially as described herein with reference to and as illustrated in any appropriate combination of the accompanying drawings.

10. Means, suitable for putting or intended to put into effect the invention defined in any of the preceding claims.