GB2175388A - Gas fire with convection air heating - Google Patents

Abstract

A gas fire has a fire box 14 in which the fire is located and a surrounding casing 18 defining a convection air space around the fire box, said air space opening into the room in which the fire is situated at its lower and upper ends; passages 24 for exhaust gases leading from said fire box through said convection air space; and an electric fan 30 at the base of said convection air space for providing a flow of air through the said space. <IMAGE>

Description

SPECIFICATION Improvements in or relating to domestic fires The present invention concerns improvements in or relating to domestic fires, especially but not exclusively those fires known as gas coal or log effect fires. Such fires are open fires having artificial coal or logs thereon under which a gas burner or series of burners is arranged so that products of combustion from the gas burner(s) pass through the artificial coal or logs to cause them to glow and, with the luminous flames produced, to give the effect of a real fire.

Objections to these fires have been raised on the basis that they give off no useful heat, all the heat resulting from combustion being carried by the exhaust gases through the flue.

In the past attempts have been made to obviate or mitigate this problem by enclosing the gas fire in a hollow casing so that air within the casing can be heated and can be circulated by convection into the room in which the fire is installed.

It is an object of the present invention to obviate or mitigate disadvantages encountered in prior arrangements.

According to the present invention there is provided a gas fire incorporating a fire box in which the fire is located, an outer casing at least partiaily surrounding the fire box to define a convection air space therearound, an inlet to the convection air space at or near its base, an outlet from the convection air space at or near its top, means passing through the convection air space in heat exchange relationship with air therein for conveying exhaust gases from the fire to a flue under which it is adapted for location and an electric fan for providing forced convection located in the convection air space at or near the base thereof.

Preferably the fire box is open-fronted, has inwardly converging sides and a substantially vertical rear which extends towards the front of the fire as the extension progresses upwardly.

Preferably a passage means for exhaust gases is provided in said extension. The passage means may comprise three hollow circular cross-section tubes.

Preferably the casing is open fronted and has substantially rectangular cross-sections in plan, front and side elevations.

Preferably a deflector is provided at the upper corner of the casing at the junction of its back and top. This deflector may be arcuate.

Preferably a transverse downwardly extending baffle is provided on the extension of the firebox rear wall on the side of the passage means nearest the fire front. Preferably a tray is mounted in the fire box for supporting the gas burner(s). The tray is preferably arranged above the level of the electric motor.

Preferably the casing has a flange at its front. Preferably a decorative covering may be provided for fitment over the flange, the covering being a sliding fit on the flange.

Preferably the external dimensions of the casing are such that the fire can be located within an existing standard fire place without the need to carry out alterations thereto.

Preferably means are provided on mounting the fire within a standard existing fire place to ensure that the flange is located in front of the front of the fire-place by a distance sufficient to enable the passage behind the flange of gas and electrical conduits to the fire box and convection air space.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig. 1 shows a front elevation of a coal/log effect gas fire; Fig. 2 shows a cross-sectional side elevation; Fig. 3 shows a plan; and Fig. 4 shows a view similar to Fig. 2 of a modified fire.

A gas fire comprises a base 10 which is substantially rectangular in plan and supports a fire box manufactured from sheet metal and comprising two inwardly converging sides 12 and a back 14 which arcs forwardly as it progresses upwardly from a point approximately midway up the fire box. The fire box is surrounded by a sheet metal casing having two facing sides 16, a back 18 and a top 20, the casing being substantially rectangular in plan and in front and side elevations. The back of the casing 18 is spaced from the back of the fire box 14 to define a space for convection air and it will be realised also that there is a space for convection air at the side of the fire box due to the inwardly converging nature of its sides. Additionally, as the top 20 of the casing is spaced above the arcuate portion of the back 14 of the fire box there is an air space above the fire box.This air space terminates in an outlet slot 22 in the front of the fire.

To provide a passage for products of combustion to a flue under which the fire is arranged there is provided three hollow tubes 24 which extend from openings in the arcuate section of the fire box back to the top 20 of the casing. It will be realised that these tubes are in heat exchange relationship with air passing through the convection air space surrounding the fire box. In the unlikely event that products of combustion tend to by-pass the exhaust tubes 24 and move towards the open front of the fire there is provided a transverse baffle 25 which extends downwardly into the fire box from a line immediately in front of the tube opening.

The fire front is surrounded by an outwardly projecting flange 26 which can be given a decorative effect by sliding a brass, copper, or stainless steel cover thereover.

The extemal dimensions of the casing are so chosen that the fire can be located within a standard fire place opening without making any modifications thereto. This is an important feature of the fire of the invention as a purchaser does not wish to have to meet the expense of costly alterations to accommodate his fire.

The drawings do not show the gas burner and artificial fuel assembly but the burner and artificial coals or logs are supported on a tray in the fire box which is located above the slotted opening 28 in the base of the rear wall 14 of the fire box which provides communication with the fire box, or more precisely with that area of the fire box below the burner tray.

To provide for forced convection a fan and electrical motor assembly 30 is mounted on two support members (not shown) fixed to the base 10 and to the rear wall 18 immediately behind the slotted opening 28. The tray for the burner(s) is perforated to allow for air used in the combustion of the gas to be supplied to the burner(s).

By locating the fan and motor assembly in the convection air space the positioning of the burner tray is not dictated to by the dimensions of the fan and motor assembly as has been the case with previous arrangements where the fan and motor assembly has been located at the front of the fire. This makes it much easier to design a fire which can provide a forced convection facility while remaining of such suitable shape and dimensions to enable its fitment in a standard fire place opening.

Spacer means (not shown) may be provided on the rear face of the flange to hold the fire spaced from the front of the fire-place opening by a distance sufficient to enable gas and electricity supply conduits to pass behind the flange into the fire.

To assist in the smooth flow of convected air through the convector air space an arcuate baffle 32 may be arranged at the junction between the rear 18 and top 20 of the casing.

Various modifications can be made without departing from the scope of the invention, for example the fire box, outer casing, front flange, exhaust tubes, electric motor positioning, gas tray burner positioning can take any convenient form.

The modification shown in Fig. 4 is provided with a floor plate 32 which defines a passage 34 for convected air from a slot 36 at the fire front to the slotted opening 28. An extension plate 38 extends forwardly of the floor plate 32 to provide a ledge on which a fire front may be supported without obstructing the air inlet slot 36. The motor 30 is mounted on supports 38 and a removable access door 40 for the motor is provided in the back 14 of the fire box.

Claims (16)

1. A gas fire incorporating a fire box in which the fire is located, an outer casing at least partially surrounding the fire box to define a convection air space therearound, an inlet to the convection air space at or near its base, an outlet from the convection air space at or near its top, means passing through the convection air space in heat exchange relationship with air therein for conveying exhaust gases from the fire to a flue under which it is adapted for location and an electric fan for providing forced convection located in the convection air space at or near the base thereof.

2. A gas fire as claimed in claim 1, in which the fire box is open-fronted, has inwardly converging sides and a substantially vertical rear which extends towards the front of the fire as the extension progresses upwardly.

3. A gas fire as claimed in claim 2, in which a passage means for exhaust gases is provided in said extension.

4. A gas fire as claimed in claim 3, in which the passage means comprises three hollow circular cross-section tubes.

5. A gas fire as claimed in any one of the preceding claims, in which the casing is open fronted and has substantially rectangular cross-sections in plan, front and side elevations.

6. A gas fire as claimed in claim 5, in which an arcuate deflector is provided at the upper corner of the casing at the junction of its back and top.

7. A gas fire as claimed in any one of claims 2 to 7, in which a transverse downwardly extending baffle is provided on the extension of the firebox rear wall on the side of the passage means nearest the fire front.

8. A gas fire as claimed in any one of the preceding claims, in which a tray is mounted in the fire box for supporting the gas burner(s).

9. A gas fire as claimed in claim 8, in which the tray is arranged above the level of the electric motor.

10. A gas fire as claimed in any one of claims 2 to 7, in which the fire box has a base plate spaced above the base of the outer casing to define an inlet air passage leading from the front of the fire to the inlet to the convection air space.

11. A gas fire as claimed in any one of the preceding claims in which the casing has a flange at its front.

12. A gas fire as claimed in claim 11, in which a decorative covering is provided for fitment over the flange, the covering being a sliding fit on the flange.

13. A gas fire as claimed in any one of the preceding claims, in which the external dimen sions of the casing are such that the fire can be located within an existing standard fire place without the need to carry out alterations thereto.

14. A gas fire as claimed in claim 13, in which means are provided on mounting the fire within a standard existing fire place to ensure that the flange is located in front of the front of the fire place by a distance sufficient to enable the passage behind the flange of gas and electrical conduits to the fire box and convection air space.

15. A gas fire substantially as hereinbefore described with reference to Figs. 1 to 3 or Fig. 4 of the accompanying drawings.

16. Any novel subject matter or combination including novel subject matter disclosed in the foregoing specification or claims and/or shown in the drawings, whether or not within the scope of or relating to the same invention as any of the preceding claims.