GB2050596A - Solid fuel effect fires - Google Patents

Abstract

A heating appliance comprises a solid fuel effect gas fire (5) in combination with a duct (9) formed in part by a back plate (11) of the appliance and a further plate (13) spaced forwardly of the back plate and a plurality of tubes (27) and upper and lower headers (19, 17) of a water tube boiler located in the duct. The hot gaseous products of combustion which are produced when the fire is in use serve to heat the water in the boiler. <IMAGE>

Description

SPECIFICATION Solid fuel effect gas fire and a boiler therefor This invention relates to the provision of a boiler for use with a solid fuel effect gas fire. Solid fuel effect gas fires are known and comprise basically a plurality of refractory bodies shaped and coloured to represent solid fuel and arranged in a heap above a gas distributor whereby, in use, gas from the distributor is burnt in the spaces between the simulated solid fuel. Such fires have a pleasing appearance and, at a distance, cannot be readily distinguished from a conventional solid fuel fire.In my Patent Number 1 541,423 1 have described and claimed such a solid fuel effect gas fire having the provision of at least one air passage for providing extra combustion air to the gaseous fuel flowing to only some of the spaces between thf refractory bodies so that, in use, the gaseous fuel provided with the extra combustion air burns with a hotter non-luminous flame and that without the extra combustion air burns with a luminous flame thereby realistically simulating a solid fuel fire.

To increase the efficiency of such a fire, I now propose to incorporate a boiler by which some of the heat generated in the fire can be used to raise the temperature of water for domestic purposes and/or for a central heating system.

Accordingly, the present invention resides in a solid fuel effect gas fire in combination with a duct for receiving products of combustion from the fire and connectible to a flue, and a boiler associated with the duct.

The duct may comprise one or a plurality of tubes surrounded by a boiler jacket in which liquid to be heated is contained. The or each tube is heated by the products of combustion passing therethrough and the liquid is heated by conduction with the tubes.

Alternatively, the products of combustion are passed along the duct and the boiler comprises a plurality of first tubes located in the duct and connected between upper and lower headers and at least one second tube located in the duct and connected to one of the headers whereby, in use, liquid circulates along the or each second tube to said header and then in parallel flow along the first tubes to te other header.

The liquid, usually water, circulating along the first and second tubes is heated by the products of combustion passing along the duct to the flue.

The duct is conveniently defined by a back plate of the appliance, which is spaced from a reflector which serves to reflect radiant heat emitted by the gas fire into the room in which it is situated.

Preferably the lower header is positioned at the bottom of the duct close to the mass of simulated solid fuel and the upper header is located at the other end of the duct adjacent an entrance to the flue. After heat exchange with the liquid the products of combustion entering the flue may be mixed with excess air to reduce the temperature still further of the combustion products as they enter into the flue.

The direction of the water flow along the first tubes is opposite to that along the or each second tube and the direction of flow along the first tubes may be in the same direction as the flow of combustion products in the duct. Alternatively, more usually with a pumped system, the flow along the first tubes may be in the opposite direction to the flow of products of combustion along the duct.

In order that the invention may be more readily understood it will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front elevation, partly in section, of a solid fuel effect heating appliance in accordance with the present invention, Figure 2 is a side elevation on the line A-A of Figure 1, and Figure 3 is a sectional plan on the line B-B of Figure 1.

Referring to the figures a solid fuel effect gas fire consists of an open topped tray 1 containing a mass of particulate refractory material with a gas inlet pipe (not shown) embedded in this material.

One or more excess air tubes 3 extend from below the tray 1 and through the tray to a position above the surface of the refractory material. A plurality of refractory bodies 5, shaped and coloured to represent solid fuel such as coal and/logs, are arranged in a heap above the tray 1. A front guard 7 of ornamental form is provided to prevent a user of the fire from seeing the tray 1 and its contents.

A duct 9 is defined by a curved back plate 11 of insulating material which is spaced from a curved reflector 13 conveniently of stainless steel and mounted above the simulated solid fuel 5. The lower end of the duct 9 is positioned close to the simulated solid fuel 5 and the upper and extends to a flue 1 5. A lower header 1 7 is positioned at the bottom of the duct behind the simulated solid fuel 5 and a second header 1 9 is positioned at the upper end of the duct. A guard 21 fits around part of the upper header 1 9 to hide it from view and a hood or canopy 23, spaced from the guard 21, provides a passage 25 for excess air which flows into the flue 1 5 where it mixes with the products of combustion to cool them.

A plurality of tubes 27 are located in the duct 9.

Referring particularly to Figure 1, a plurality of the tubes 27, referred to as the first tubes, are connected between the upper and lower headers.

One tube 27', referred to as the second tube, is connected to the lower header 1 7 and to a compartment 29 in the upper header 19, and is separated from the remaining part of the header by a partition wall 31.

A plurality of tubular projections 33 are in communication with the lower header 1 7 and project into, and are embedded in, the mass of simulated solid fuel 5. These tubular projections are disclosed in my co-pending application No.

14870/77.

In use, the gas supplied to the fire is ignited and it burns in the spaces between the simulated soUd fuel 5. Some of the fuel burns with luminous flames and that which is mixed with excess air through the tubes 3 burns with non-luminous flames. The refractory bodies 5 are heated and begin to glow. The water in the projections 33, and hence in the lower header 17, is heated by conduction and radiation and it flows upwardly through the tubes 27 apart from the tube 27'. The products of combustion from the fire are drawn up the duct 9 and, after being mixed with excess air passing beneath the canopy 23, passes into the flue 1 5.A plurality of openings or slots 35 are provided in the reflector 13 above the level of the refractory bodies heaped on the tray to permit further products of combustion to enter into the duct without greatly interfering with the desired flame patterns. These hot products of combustion transfer much of their heat to the water in the tubes 27 causing it to rise by convection to the header 1 9. The water flows through the pipes 27 in parallel flow. The upward flow along the pipes 27 draws colder water downwardly along the boiler tube 27' to replenish the supply in the lower header 17. The water heated in this way can be used for domestic purposes and/or for heating one or more central heating radiators.

If desired, a pumped flow can be arranged in which the water is pumped downwardly from the header 19 and along the tubes 27 to the lower header 1 7 so that it is in counter-current to the flow of the products of combustion along the duct 9. This ensures a greater heat transfer between the products of combustion and the water in the tubes 27. The water then flows upwardly along the tube 27'. To prevent any water hammer and to provide automatic rectification of any water degassing, a small hole, say 2 mm diameter, may be drilled through the partition wall 31.

The diameter of the tube 27' may be greater or less than that of each of the tubes 27.

Guard 21 is preferably removable to gain access to the header to allow ease of making the water connections both to and from the boiler.

Reflector 13 is removable to enable the duct and tubes to be periodically cleaned.

As mentioned above, the products of combustion may pass along the tubes and in this case the tubes are located in a sheil type boiler containing the liquid to be heated.

Claims (6)

1. A heating appliance comprising a solid fuel effect gas fire, a duct defined in part by a back plate of the appliance and a further plate spaced forwardly of the back plate, said duct being connectible to a flue and being arranged to receive gaseous products of combustion when the fire is in use, and a plurality of tubes of a water tube boiler located in the duct and connected at their ends tb respective upper and lower headers located in the duct.

2. A heater appliance as claimed in claim 1, in which an opening is provided below said further plate to allow products of combustion to flow therethrough into the duct and said further plate is apertured above the level of the fire to permit further products of combustion to flow therethrough into the duct.

3. A heating appliance as claimed in claim 1 or 2, in which the surface of the further plate which faces the fire is arranged to act as a reflector.

4. A heating appliance as claimed in any preceding claim, in which a plurality of tubular projections in communication with the lower header are embedded in a heap of refractory bodies shaped and coloured to simulate solid fuel and forming part of the gas fire.

5. A heating appliance as claimed in any preceding claim, in which all of the tubes of the boiler are connected to the lower header and one of the tubes is connected to an upper header which is separate from the upper header to which the other tubes are connected.

6. A heating appliance substantially as hereinbefore described with reference to the accompanying drawing.