GB2131158A

GB2131158A - Coal effect gas fire

Info

Publication number: GB2131158A
Application number: GB08232446A
Authority: GB
Inventors: Thomas Raymond Collier
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-11-12
Filing date: 1982-11-12
Publication date: 1984-06-13
Also published as: GB2131158B

Abstract

A coal effect gas fire has a bed of vermiculite (23) supported on the upper perforated wall (12) of a housing (2). A gas/air mixture is supplied to the housing (2), passes through the perforations in the wall (12), through the bed of vermiculite (23) and burns between refractory bodies (25) which simulate coal or logs. A back plate (7) supports an insulating blanket (24). The width of the housing (2) is at least three times its front to rear dimension, preferably five times, and, while giving the appearance of a full width and full depth fire, the fire can be particularly economical. <IMAGE>

Description

SPECIFICATION Coal effect gas fire The invention relates to a coal effect gas fire.

Coal effect gas fires have been previously proposed wherein the recess in a normal fire-back of an open hearth is filled with a tray containing particulate refractory material, in the bottom of the tray a perforated pipe or diffuser plate is provided through the perforations in which or from around the edges of which, a gas or gas/air mixture can be caused to issue, the gas or mixture passing upwardly through the mass of particulate refractory material, and a plurality of refractory bodies shaped and coloured to simulate solid fuel being disposed on the surface of the mass of particulate refractory material so that as the gas burns at the surface thereof, it burns between the refractory bodies to give the appearance of coal burning in a grate.

While such previously proposed coal effect gas fires have a satisfactory appearance, they are unduly expensive to operate in that they have, if they are to have a realistic effect, an unduly high gas consumption.

According to the invention, there is provided a coal effect fire having a plurality of refractory bodies supported on a bed of vermiculite, through which bed gas is supplied to burn at the upper surface of the bed and heat the refractory bodies.

Thus the vermiculite can disperse the gas supply such that the gas burns with a lambientflame rather than a jet flame.

Preferably, the coal effect gas fire includes a box-like housing having its upper surface perforated and supporting the bed of vermiculite, the gas supply supplies gas to the interior of the housing and a back plate extends upwardly and rearwardly at the rear of the housing.

Advantageously, the housing is so proportioned that its perforated upper surface has a dimension from side to side which is at least three times its dimension from front to rear.

Preferably, the housing is supported on three legs and comprises an elongate rectangular box with the walls thereof, except for the wall forming the perforated upper surface, formed integral with one another and integral with the back plate.

Control means for the gas supply are preferably supported on a bracket beneath the housing. Afront plate may be provided, preferably to hook onto the housing, and may include an opening to give access to the control means.

The back plate in use is preferably covered by a layer of radiant ceramic fibre insulating material, preferably in the form of a blanket of the material sold under the Trade Mark KAIOWOOL by Morganite Ceramics Limited.

The wall of the housing forming the perforated surface is preferably at a level lower than the surrounding wall, thereby to contain the bed of vermiculite and the gas or a gas/air mixture supplied to the housing passes through the perforations in the upper wall of the housing, through the bed of vermiculite and burns at the upper surface of the bed of vermiculite where it contacts secondary air from the atmosphere.

Advantageously in use, only the layer of insulating material covering the back plate and the refractory bodies lying on the bed ofvermiculite and resting against the layer of insulating material are heated, that is to say all metal parts remain cold.

The heating effect of the fire can be enhanced by including, at a position adjacent the upper edge of the back plate but spaced therefrom to leave a gap through which combustion fumes can pass to the chimney, a reflecting plate, or a box-like member, which box-like member may incorporate air inlet means and air outlet means such that heat from the fire causes convection currents to flow from said air inlet means to said air outlet means or may be formed as a tank to contain water to provide a hot water supply for drawn hot water or for a central heating system.

By providing the housing supporting the bed of vermiculite of much greater width from side to side than depth from front to rear, an impression of a full depth coal fire can be given for a much smaller surface area of the bed through which the gas permeates such that the rate of usage of gas is considerably reduced compared with previously proposed fires and the fire is thus much more economic to operate. The three legs can give stable mounting, that is to say mounting without rocking, even on uneven surfaces.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which Figure 1 is a part sectional side view of a coal effect fire according to the invention; Figure 2 is a corresponding front elevation; Figure 3 is a view similar to Figure 1 but including a bed of vermiculite, insulating blanket and refractory bodies; Figure 4 is a front elevation of the fire of Figure 3; and Figure 5 is a view similar to Figure 3 but showing additional means to enhance the heating effect of the fire.

Referring to the drawing and firstly to Figures 1 and 2, a coal effect fire generally indicated at 1 has a box-like housing 2 having a front wall 3, a bottom wall 4, a rear wall 5 and end walls 6 (only one of which is shown). The housing 2 is formed of sheet metal by cutting and bending but the walls 3,4,5 and 6 are all formed from one piece of sheet material such that the only welding required is at the junction of the sides ofthe end walls 6 and the front wall 3 and rearwall 5. The fire also includes a upwardly and rearwardly sloping back wall 7 with a horizontal portion 8 at its upper end, the back wall 7 and portion 8 being formed integral with the walls 3, 4, 5 and 6.

The housing 2 is supported on legs 9 and 10 at the front and a leg 11 at the rear.

Inserted in the upper end of the box but at a level below the upper edges of the walls 3,5 and 6, is a horizontal upperwall 12 with perforations 13 therein.

A cover member in the form of a vertical plate 14 may be provided to hook onto the upper end of the front wall 3.

Slung beneath the housing 2 on a sheet metal bracket 15 is a control unit 16 having an input 17 for a gas supply, control knobs 18 for controlling gas supply to the fire and spark ignition therefor and a gas outlet 19 leading to the fire. The gas outlet 19 suppiies gas by means of a pipe 20 to a gas connector 21 at the rear of the housing 2, which gas connector 21 may include means for mixing primary air with the gas. The housing 2 has a width, that is to say between the two end walls 6, at least three times its depth, that is to say the distance between the front wall 3 and the rear wall 5, and preferably the width is approximately five times the depth.

As indicated at the lefthand side of Figure 2, gas supply monitor means 22, preferably in the form of a pilot flame and a thermocouple, may be provided to monito the supply of gas and control the control means 16.

In use, the front cover plate 14 is provided to conceal the space beneath the housing 2, as shown in Figure 3 but not shown in Figure 4, and a bed of vermiculite 23 is provided on the perforated plate 12 up to the level approximately of the upper edge of the front wall 3 and the end wall 6. A blanket 24, for example of Kaiowool and 21/2 cm thick, is provided to cover the back plate 7 and the portion 8 thereof and has its lower end resting on the rear part of the perforated plate 12. Refractory bodies 25 preferably formed of ceramic fibre are stacked on the top of the bed 23 of vermiculite and rest against the blanket 24.

On supply of gas through the connector 21 to the interior of the housing 2, the gas is mixed with air by the connector 21 and the gas/air mixture passes through the perforations 13 in the perforated plate 12 and through the interstices in the bed 23 of vermiculite and is ignited at the upper surface of the bed of vermiculite. The heat from the burning gas causes the refractory bodies 25 to glow red and simulate burning coals.

Figure 5 shows that a plate 26 is provided adjacent the upper end of the back plate 7 and approximately perpendicular thereto, the lower edge of the plate being spaced from the refractory bodies 25 so that combustion fumes, indicated by solid lines with arrows thereon, can pass between the blanket 24 and the plate 26 to pass to atmosphere through a chimney (not shown). Heat rising from the glowing refractory bodies 25, which heat is indicated by the dotted line arrows, strikes the plate 26 and is reflected outwardly.

If desired, the plate 26 may form the front wall of a housing generally indicated at 27, which housing may have air inlet connection pipes shown at 28 with outlet apertures 29 being provided at the upper part of the plate 26 such that air will be drawn by the heat of the fire inwardly through the tube 28, as indicated by the arrow 30, and will pass through the outlet 29 in the form of convection currents. Alternatively, the housing 27 could be formed as a watertankto provide a supply of hot water.

One 18 inch wide example of a coal effect fire according to the invention burnt 21,000 B T U per hour on full gas supply and only 13,000 B T U per hour on low supply while giving a realistic coal effect. A 16 inch side version burnt 19,000 B T U per hour on full gas supply and only 13,000 B T U per hour on low supply while still giving a good coal effect.

One reason for the economy is that, as shown in Figure 5 where the rear wall 31 and floor wall 32 of a fire-back are illustrated, is that instead of the fire forming the full base of the fire-back, there is a considerable void behind the back plate 7 such that gas only burns over a relatively small area represented by the surface of the perforated plate 12 compared with the overall floor area of the fire-back.

CLAIMS (Filed on 28th October 1983) 1. A coal effect gas fire having a plurality of refractory bodies supported on a bed of vermiculite, through which bed gas is supplied to burn at the upper surface of the bed and heat the refractory bodies.

2. A coal effect gas fire according to claim 1, including a box-like housing having its upper surface perforated and supporting the bed of vermiculite, to the interior of which housing the gas is supplied, and a back plate extending upwardly and rearwardly at the rear of the housing.

3. A coal effect gas fire according to claim 2, in which the housing is so proportioned that its perforated upper surface has a dimension from side to side which is at least three times its dimension from front to rear.

4. A coal effect gas fire according to claim 2 or claim 3, in which the housing is supported on three legs and comprises an elongate rectangular box with the walls thereof, except for the wall forming the perforated upper surface, formed integral with one another and integral with the back plate.

5. A coal effect gas fire according to claim 4, including control means for the gas supply supported on a bracket beneath the housing and front plate including an opening to give access to the control means.

6. A coal effect gas fire according to any one of claims 2 to 5, in which the back plate in use is covered by a layer of radiant ceramic fibre insulating material.

7. A coal effect gas fire according to any one of claims 2 to 6, in which the wall of the housing forming the perforated surface is at a level lower than the surrounding wall, thereby to contain the bed of vermiculite and the gas or a gaslair mixture supplied to the housing passes through the perfora tions in the upper wall of the housing, through the bed of vermiculite and burns at the upper surface of the bed of vermiculite where it contacts secondary air from the atmosphere.

8. A coal effect gas fire according to any one of claims 2 to 7, in which in use, only the layer of insulating material covering the back plate and the refractory bodies lying on the bed of vermiculite and resting againstthe layer of insulating material are heated, that is to say all metal parts remain cold.

9. A coal effect gas fire according to any one of claims 2 to 8, in which the heating effect of the fire can be enhanced by including, at a position adjacent the upper edge of the back plate but spaced

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Slung beneath the housing 2 on a sheet metal bracket 15 is a control unit 16 having an input 17 for a gas supply, control knobs 18 for controlling gas supply to the fire and spark ignition therefor and a gas outlet 19 leading to the fire. The gas outlet 19 suppiies gas by means of a pipe 20 to a gas connector 21 at the rear of the housing 2, which gas connector 21 may include means for mixing primary air with the gas. The housing 2 has a width, that is to say between the two end walls 6, at least three times its depth, that is to say the distance between the front wall 3 and the rear wall 5, and preferably the width is approximately five times the depth. As indicated at the lefthand side of Figure 2, gas supply monitor means 22, preferably in the form of a pilot flame and a thermocouple, may be provided to monito the supply of gas and control the control means 16. In use, the front cover plate 14 is provided to conceal the space beneath the housing 2, as shown in Figure 3 but not shown in Figure 4, and a bed of vermiculite 23 is provided on the perforated plate 12 up to the level approximately of the upper edge of the front wall 3 and the end wall 6. A blanket 24, for example of Kaiowool and 21/2 cm thick, is provided to cover the back plate 7 and the portion 8 thereof and has its lower end resting on the rear part of the perforated plate 12. Refractory bodies 25 preferably formed of ceramic fibre are stacked on the top of the bed 23 of vermiculite and rest against the blanket 24. On supply of gas through the connector 21 to the interior of the housing 2, the gas is mixed with air by the connector 21 and the gas/air mixture passes through the perforations 13 in the perforated plate 12 and through the interstices in the bed 23 of vermiculite and is ignited at the upper surface of the bed of vermiculite. The heat from the burning gas causes the refractory bodies 25 to glow red and simulate burning coals. Figure 5 shows that a plate 26 is provided adjacent the upper end of the back plate 7 and approximately perpendicular thereto, the lower edge of the plate being spaced from the refractory bodies 25 so that combustion fumes, indicated by solid lines with arrows thereon, can pass between the blanket 24 and the plate 26 to pass to atmosphere through a chimney (not shown). Heat rising from the glowing refractory bodies 25, which heat is indicated by the dotted line arrows, strikes the plate 26 and is reflected outwardly. If desired, the plate 26 may form the front wall of a housing generally indicated at 27, which housing may have air inlet connection pipes shown at 28 with outlet apertures 29 being provided at the upper part of the plate 26 such that air will be drawn by the heat of the fire inwardly through the tube 28, as indicated by the arrow 30, and will pass through the outlet 29 in the form of convection currents. Alternatively, the housing 27 could be formed as a watertankto provide a supply of hot water. One 18 inch wide example of a coal effect fire according to the invention burnt 21,000 B T U per hour on full gas supply and only 13,000 B T U per hour on low supply while giving a realistic coal effect. A 16 inch side version burnt 19,000 B T U per hour on full gas supply and only 13,000 B T U per hour on low supply while still giving a good coal effect. One reason for the economy is that, as shown in Figure 5 where the rear wall 31 and floor wall 32 of a fire-back are illustrated, is that instead of the fire forming the full base of the fire-back, there is a considerable void behind the back plate 7 such that gas only burns over a relatively small area represented by the surface of the perforated plate 12 compared with the overall floor area of the fire-back. CLAIMS (Filed on 28th October 1983)

1. A coal effect gas fire having a plurality of refractory bodies supported on a bed of vermiculite, through which bed gas is supplied to burn at the upper surface of the bed and heat the refractory bodies.

therefrom to leave a gap through which combustion fumes can pass to the chimney, a reflecting plate, or a box-like member, which box-like member may incorporate air inlet means and air outlet means such that heat from the fire causes convection currents to flow from said air inlet means to said air outlet means or may be formed as a tank to contain water to provide a hot water supply for drawn hot water or for a central heating system.

10. A coal effect gas fire substantailly as hereinb efore described and illustrated with reference to the accompanying drawings.