IMPROVEMENTS IN OR RELATING TO FIRE ASSEMBLIES

Abstract: Gas fire assembly (10) comprising a turbine (32) rotatably mounted in a first conduit (18) through which exhaust gases pass. The turbine (32) is drivably connected to freely rotatable fans (40, 42) located in a second conduit located immediately behind the gas burner (12), such that convected air is warmed in the second conduit (22) and pulled therethrough by the fans (40, 42) to push convected air into a room space.

Description: IMPROVEMENTS IN OR FT ATTNft TO FIRE ASSFMBI.TFS This invention relates to fire assemblies. More particularly, but not exclusively, this invention relates to convection type fire assemblies. Conventional convection type gas fires operate by providing a convection conduit at the rear of the fire which is heated by the gas burner. The air in the conduit is thus heated, which is passed by convection into the room. Ways have been sought in order to enhance the flow of air through the convection conduit. According to the invention there is provided a fire assembly for heating a room space, comprising a first conduit to allow vapour from the heating means to exhaust from the assembly, a second conduit arranged in association with the heating means such that air in the second conduit is heated by the heating means, vapour operated drive means arranged in the first conduit, and air impeller means drivably connected to the drive means, the assembly being arranged such that vapour exhausted from the heating means operates the drive means to drive the impeDer means thereby to impel heated air through the second conduit to heat the room space. Preferably, the air impeller means comprises a rotary member arranged to be rotatable by the air drive means. Preferably, the rotary member comprises a fan to impel the air through the second conduit. Preferably the first conduit extends through the second conduit and the air impeller means may comprise rotary members arranged respectively on either side of the first conduit. A plurality of first conduits may be provided, each extending through the second conduit, with drive means in each first conduit, and respective rotary members arranged on either side of some or all of the first conduits. The drive means is preferably arranged to be rotated by vapour from the heating means. The drive means may comprise one or more turbines arranged to be rotatable by vapour exhausted from the fire assembly. Preferably, the drive means is connected by connection means to the impeller means. The connection means may comprise a shaft extending through the or each first conduit and the second conduit, upon which shaft the drive means and impeller means are mounted. Preferably, the heating means comprises a gas fired burner, and the vapour exhausted from the fire assembly may comprise flue gas formed during the burning of gas in the burner. The second conduit may extend from an air inlet at a lower region of the fire assembly to an air outlet at an upper region of the fire assembly. Preferably, the fire assembly comprises a front and a rear region, the heating means preferably being provided at said front region and the second conduit preferably being provided at said rear region. A chamber may be provided at said front region to house the heating means. Preferably, the air inlet for the second conduit is provided below said chamber and the air outlet is preferably provided above said chamber. Heat exchange means may be provided on the rear of the chamber within the second conduit. The or each first conduit preferably extends from an inlet or inlets opening into said chamber to an outlet at the rear of said fire assembly. Preferably, the or each first conduit is arranged towards the upper region of said fire assembly. lϊmbodiments of the invention will now be described by way of example only in which: Fig. 1 is a schematic front, part sectional view of a fire assembly according to the invention, showing a drive means and an impeller means; Fig. 2 is a view along the lines II-II in Fig. 1; Fig. 3 is a view along the lines III-III in Fig. 2; and Fig. 4 is a plan view of part of a modified assembly according to the invention. Referring to the drawings, there is shown a fire assembly 10 which is in the form of a gas fire, for heating a room space. The fire assembly 10 comprises heating means in the form of a gas burner 12. The gas burner 12 may be in the form of a live fuel effect burner, and may include imitation fuel, schematically represented at 14. The gas burner 12 is connected to the mains gas supply in the normal way. The gas burner 12 is housed within a chamber 16 which is in communication with the region external of the fire assembly 10 via a first conduit 18. The chamber 16 is isolated from the room space to prevent flue gases entering the room space. When the gas burner 12 is burning, flue gases are emitted which pass from the burner 12 in the direction of the arrow Cl to be exhausted from the fire assembly 10 via the first conduit 18 in the direction of the arrow C2. The flue gases are usually then passed by a chimney or other appropriate construction to a region outside the building. The chamber 16 is defined at the rear by a back wall 20. A second conduit 22 extends from an inlet 24 at a lower region of the fire assembly 10 to an outlet 26 at an upper region of the fire assembly 10. The second conduit 22 extends behind the chamber 16 and is defined by the back wall 20 of the chamber 16 and a rear wall 28 of the fire assembly 10. When the gas burner 12 is in operation, to burn gas fed from the mains, the heat produced thereby warms the back wall 20 which, in turn, warms the air in the second conduit 22 directly behind the back wall 20. The air in the second conduit 22 then rises by convection in the direction of the arrows D. The rising air in the section of the conduit 22 behind the back wall 20 creates a partial vacuum which causes air to be sucked into the conduit 22 from outside the fire assembly 10 via the inlet 24. The rising air then passes out of the conduit 22 via the outlet 26 to warm the room. Vapour operated drive means 30 is mounted in the first conduit 18. The drive means 30 comprises a turbine 32 mounted on a shaft 34. As can be seen, the first conduit 18 extends through the second conduit 22 centrally thereof. The first and second conduits 18, 22 are isolated from each other by walls 36,38. The shaft 34 extends from the turbine 32 through the walls 36,38 and is journalled in suitable bearings in the walls 36,38. Appropriate sealing means are provided to ensure that the flue gases passing through the first conduit 18 do not leak into the second conduit 22. Mounted on the shaft 34 in the second conduit 22, at either side of the turbine 32 are first and second rotary fans 40,42, the purpose of which is to impel air through the second conduit 22 thereby enhancing the warming of the room as effected by convection. In operation, the turbine 32 is rotated about the shaft 34 by the flue gasses passing through the first conduit 18. Since the turbine 32, and the fans 40,42 are each fixedly mounted on the shaft 34, the rotation of the turbine 32 causes corresponding rotation of the fans 40,42. The fans 40, 42 are provided with a plurality of vanes 44, which are so angled that rotation thereof by the rotating turbine 32 causes the fans 40,42 to impel air in the direction of the arrows D. This impelling of the air by the fans 40,42 enhances the flow of warm air through the second conduit 22 over that which would be caused by convection alone, thereby improving the efficiency of the fire assembly 10. The flue gases will be pulled by the chimney or other structure through the first conduit 18. The taller the chimney, generally the greater the pull provided thereby. In conventional fires this can be disadvantageous in taking heat too quickly from the fire. However, in assemblies according to the invention, the greater the pull the greater the speed of rotation of the turbine 30 and hence fans 40,42, and thus the circulation of hot air into the room space. Fig. 4 shows a modified arrangement with three first conduits 46,48,50 extending through the second conduit 22 which is hence divided into four parts 52. The central first conduit 48 is larger than the two side first conduits 46,50, and each first conduit is equispaced from each other and the sides of the second conduit 22, by the parts 52. Each first conduit 46,48,50 locates a respective size turbine 54, and fans 56 are located in each of the parts 52. The turbines 54 and fans 56 are all mounted on a shaft 58. This arrangement provides for a more even draw off of flue gases, and also better heat transfer. Various other modifications can be made without departing from the scope of the invention. For example, the first conduit 18 could be arranged to pass through the second conduit 22 at one side thereof. In such an arrangement, the fans 40,42 could be replaced by a single fan. In fact a wide variety of configurations of the first and second conduits are possible. Also, instead of a direct drive between the turbine 32 and the fans 40,42 an appropriate gearing arrangement could be provided. Heat exchanger means such as fins, could be provided on the rear of the back wall 20 and/or elsewhere to assist heating of the air passing through the second conduit. Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims: riaims;- 1. A fire assembly (10) for heating a room space, comprising a first conduit (18,46,48,50) to allow vapour from the heating means (12) to exhaust from the assembly (10), a second conduit (22) arranged in association with the heating means (12) such that air in the second conduit is heated by the heating means (12), characterised in that the assembly also comprises vapour operated drive means (30) arranged in the first conduit (18,46,48,50), and air impeller means (40,42,56) drivably connected to the drive means (30), the assembly (10) being arranged such that vapour exhausted from the heating means (12) operates the drive means (30) to drive the impeller means (40,42,56) thereby to impel heated air through the second conduit (22) to heat the room space. 2. An assembly according to claim 1, characterised in that the air impeller means comprises a rotary member (40,42,56) arranged to be rotatable by the air drive means (30). 3. An assembly according to claim 2, characterised in that the rotary member comprises a fan (40,42,56) to impel the air through the second conduit (22). 4. An assembly according to any of claims 1 to 3, characterised in that the first conduit (18,46,48,50) extends through the second conduit (22). 5. An assembly according to claim 4 when dependent on claims 2 or 3, characterised in that the air impeller means comprises rotary members (32,54) arranged respectively on either side of the first conduit (18). 6. An assembly according to claim 5, characterised in that a plurality of first conduits (46,48,50) are provided, each extending through the second conduit (22), with drive means (54) in each first conduit, and respective rotary members (56) arranged on either side of some or all of the first conduits (46,48,50). 7. An assembly according to any of the preceding claims, characterised in that the drive means (30) is arranged to be rotated by vapour from the heating means (12). 8. An assembly according to claim 7, characterised in that the drive means (30) comprises one or more turbines (32,54) arranged to be rotatable by vapour exhausted from the fire assembly (10). 9. An assembly according to any of the preceding claims, characterised in that the drive means (30) is connected by connection means (34,58) to the impeller means (40,42,56). 10. An assembly according to claim 9, characterised in that the connection means comprises a shaft (34,58) extending through the or each first conduit (18,46,48,50) and the second conduit (22), upon which shaft (34,58) the drive means (30) and impeller means (40,42,56) are mounted. 11. An assembly according to any of the preceding claims, characterised in that the heating means comprises a gas fired burner (12). 12. An assembly according to claim 11, characterised in that the vapour exhausted from the fire assembly (10) comprises flue gas formed during the burning of gas in the burner (12). 13. An assembly according to any of the preceding claims, characterised in that the second conduit (22) extends from an air inlet (24) at a lower region of the fire assembly (10) to an air outlet (26) at an upper region of the fire assembly (10). 14. An assembly according to any of the preceding claims, characterised in that the fire assembly (10) comprises a front and a rear region, the heating means (12) preferably being provided at said front region and the second conduit (22) preferably being provided at said rear region. 15. An assembly according to claim 14, characterised in that a chamber (16) is provided at said front region to house the heating means (12). 16. An assembly according to claim 15 when dependent on claim 13, characterised in that the air inlet (24) for the second conduit (22) is provided below said chamber (16). 17. An assembly according to claims 15 or 16 when dependent on claim 13, characterised in that the air outlet (26) for the second conduit (22) is provided above said chamber (16). 18. An assembly according to any of claims 15 to 17, characterised in that heat exchange means is provided on the rear of the chamber (16) within the second conduit (22). 19. An assembly according to any of claims 15 to 18, characterised in that the or each first conduit (18,46,48,50) extends from an inlet or inlets opening into said chamber (16) to an outlet at the rear of said fire assembly. 20. An assembly according to claim 19, characterised in that the or each first conduit (18,46,48,50) is arranged towards the upper region of said fire assembly (10).

Inventors: GREEN MICHAEL JOHN, KINDER JOHN MICHAEL, GREEN, MICHAEL, JOHN, KINDER, JOHN, MICHAEL
Applicants: GREEN MICHAEL JOHN, KINDER FIRES LTD, KINDER JOHN MICHAEL, GREEN, MICHAEL, JOHN, KINDER FIRES LIMITED, KINDER, JOHN, MICHAEL
Application year: 1997
Main classification: F24B7
IPC codes: F24B1