GB2481026A

GB2481026A - Space heater with selective flow to divided cavity

Info

Publication number: GB2481026A
Application number: GB1009582.6A
Authority: GB
Inventors: Frederick Frank Waghorn
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-06-08
Filing date: 2010-06-08
Publication date: 2011-12-14
Anticipated expiration: 2030-06-08
Also published as: GB201009582D0; GB2481026B

Abstract

A space heating, such as a solid fuel stove or oven, has a combustion chamber 11 with a cavity 25 at a rear or side face divided from the combustion chamber by a plate 24, the cavity being in selectable communication with a source of air from the combustion chamber 11 and a source of air from outside the combustion chamber. The selectable communication can be by means of a pivotable flap 34, worked manually or thermostatically to prevent heating above a predetermined temperature, and some embodiments the outside air can be from below the fire bed. A heat exchanger 30 for central heating can be in the cavity 25. Various grate arrangements are described.

Description

Space Heatinu The present invention relates to space heating, in particular to room heaters such as solid fliel stoves.

Solid ftiel room heaters typically provide very little, if any, control over the heat generated and thus output to the room. Thus once a fire in the heater is established, it is difficult to cause a reduction in heat output other than by reducing the airflow through the fuel and allowing ftiel within the heater to bum down. This is a particular problem with solid ftiel room heaters which include a heat exchanger to supply heated water to a central heating system since lack of control can lead to excessive heat expansion of and pressure within the heat exchanger. This can result in premature failure of the heat exchanger. The present invention seeks to provide a solution to this problem.

In its broadest sense, the present invention provides a space heating apparatus comprising a combustion chamber for receipt of a combustible ftiel having a cavity divided from the combustion chamber by means of a cavity plate. The cavity is in selectable communication with a source of air from the combustion chamber and a source of air from outside the combustion chamber.

Suitably, the cavity plate is formed of an insulating material, suitably an insulating board.

Preferably, the cavity is in selectable communication with the sources of air by means of a

pivotable flap.

The cavity is formed at a rear or side face of the apparatus.

Preferably, the apparatus further comprises a thermostatic sensor and flap adjustment means arranged that when the temperature of the thermostatic sensor exceeds a first predetermined temperature, the flap is caused to move to a position in which the cavity is in communication with the source of air from outside the combustion chamber. More preferably, when the temperature of the thermostatic sensor falls below a second predetermined temperature, the flap is caused to move to a position in which the cavity is in communication with the source of air from within the combustion chamber.

In preferred embodiments, the heater ftirther comprises a heat exchanger for a central heating system, the heat exchanger being positioned within the cavity.

In one embodiment, the source of air from outside the combustion chamber is a source of air from a rear face of the heater. In an alternative embodiment, the heater ftirther comprises a fire bed or fire grate supported above a floor of the heater and the source of air from outside the combustion chamber is a source of air from below the fire bed or fire grate.

The above and other aspects of the present invention will now be described in further detail, by way of example only, with reference to the accompanying figures, in which: Figure 1 is a sectional view of a first embodiment of a heater in accordance with the present invention in the form of a heater having a fire grate in a first configuration; Figure 2 is a sectional view of the embodiment of Figure 1 in a second configuration; Figure 3 is a sectional view of a second embodiment of a heater in accordance with the present invention in the form of a wood-burning heater in a first configuration; Figure 4 is a sectional view of the embodiment of Figure 3 in a second configuration; Figure 5 is a sectional view of a third embodiment of a heater in accordance with the present invention in the form of a heater having a fire bed in a first configuration; Figure 6 is a sectional view of the embodiment of Figure 5 in a second configuration; Figure 7 is a sectional view of a modification of the embodiment of Figure 5 in a first configuration; and Figure 8 is a sectional view of the embodiment of Figure 7 in a second configuration; and Figure 9 is a part sectional view of a modification of the embodiment of Figure 1 in combination with an oven.

Referring to Figures 1 and 2, there is shown a first embodiment of a heater 10 in accordance with the present invention. The heater comprises a combustion chamber 11 having a glass front 12 facing, in use, the room to be heated. The heater includes a base 13 above which is supported a fire grate 14 on which a combustible material to be burned, such as coal, is placed such that a space 15 is formed between base 13 and fire grate 14 to allow for flow of air through grate 14. Air to space 15 is regulated by a regulator valve 20 in a conventional manner. Combustion chamber 11 is in communication with a flue 21 for exhausting waste gasses and includes a throat plate 22 of conventional construction.

The heater 10 includes a rear wall 23 and a generally parallel cavity plate 24 forming a cavity 25 between the combustion chamber 11 and the rear wall 23 of the heater. In the embodiment shown, a heat exchanger 30 is mounted within cavity 25. Heat exchanger 30 is coupled to a central heating system in a conventional manner.

Cavity 25 is in selective communication with combustion chamber 11 at a lower end of the cavity by means of a first aperture 31 such that air (and frame) can be arranged to flow from the combustion chamber to the cavity. The cavity is also in selective communication with a chamber 33 from which air from outside the combustion chamber, which will accordingly be at a lower temperature, by means of a second aperture 32. In the embodiment shown, chamber 33 is open at the rear of the heater and so draws cooler air in from around and underneath the heater.

Selective communication between cavity 25 and first and second apertures 31,32 is arranged by means of a pivotable flap 34 which is moveable between a first configuration in which first aperture 31 is open and second aperture 32 is closed (Figure 1) allowing heated air from the combustion chamber to enter cavity 25; and a second configuration in which the first aperture 31 is closed and second aperture 32 is open (Figure 2) allowing cooler air from outside the combustion chamber 11 to enter cavity 25.

In the second configuration, it will be appreciated that the cooler air entering cavity 25 will act to avoid further increase in the temperature of the heat exchanger 30.

Suitably, cavity plate 24 is formed of an insulating material, such as insulation board. In alternative embodiments, cavity plate 24 is a metal plate.

Pivotable flap 34 may be manually operated by means of a mechanical linkage. In preferred embodiments, however, the heater includes a thermostatic sensor (not shown) within or adjacent cavity 25 or heat exchanger 30 in operative connection with a flap actuating motor, gearing and switching assembly which acts to position flap 34 into the first configuration when the sensor senses a temperature below a first predetermined value and which acts to position the flap 34 into the second configuration when the sensor senses a temperature above a second predetermined temperature.

In preferred embodiments, the assembly further acts on valve 20 by decreasing air pressure to reduce primary airflow to the combustion chamber to reduce the rate of combustion and thus the temperature within the combustion chamber.

In the embodiments shown, an upper end of cavity 25 includes a secondary flap 35 adapted to close off the upper end of the cavity to allow a more rapid build up of heat within the cavity during the initial heating up of the apparatus.

Figures 3 and 4 are views corresponding with those of Figures 1 and 2 respectively of a second embodiment in the form of a wood-burning stove in which wood is placed directly on the base 13 of the heater. The other features of this embodiment are common to the embodiment of Figures 1 and 2 above and will not be described in further detail.

Figures 5 and 6 are further views corresponding with Figures 1 and 2 respectively showing a variation in which the heater includes a fire bed 40 on which a combustible material is supported above the base 13 of the heater. The fire bed is of the type described in our co-pending patent application GB 1004830.4 and will not be described in further detail here.

In this embodiment, chamber 33 is in communication with cavity 15 below the fire bed 40 rather than being in communication with the rear of the heater.

Figures 7 and 8 are further corresponding views of a variation of the embodiment of Figures 5 and 6 in which chamber 33 is in communication with the rear of the heater as with the embodiments of Figures 1 to 4, but without a heat exchanger 30 within cavity 25.

This illustrates that the present invention is equally applicable to stand-alone heaters not forming part of a central heating installation.

Figure 9 shows a modification of the embodiment of Figures 1 and 2 in which cavity 25 is formed at a side of the combustion chamber rather than at its rear and an oven cavity 41 is provided adjacent the cavity 25 to be heated by air and flame passing through aperture 31 into cavity 25.

Claims

CLAIMS: 1. A space heating apparatus comprising a combustion chamber for receipt of a combustible fuel having a cavity at a rear face thereof, divided from the combustion chamber by means of a cavity plate, wherein the cavity is in selectable communication with a source of air from the combustion chamber and a source of air from outside the combustion chamber.
2. A space heating apparatus as claimed in Claim 1 wherein the cavity plate is formed of an insulating material, suitably an insulating board.
3. A space heating apparatus as claimed in Claim 1 or Claim 2 wherein the cavity is in selectable communication with the sources of air by means of a pivotable flap.
4. A space heating apparatus as claimed in any preceding claim wherein the heater further comprises a thermostatic sensor and flap adjustment means arranged that when the temperature of the thermostatic sensor exceeds a first predetermined temperature, the flap is caused to move to a position in which the cavity is in communication with the source of air from outside the combustion chamber.
5. A space heating apparatus as claimed in Claim 5 wherein when the temperature of the thermostatic sensor falls below a second predetermined temperature, the flap is caused to move to a position in which the cavity is in communication with the source of air from within the combustion chamber.
6. A space heating apparatus as claimed in any preceding claim wherein the heater further comprises a heat exchanger for a central heating system, the heat exchanger being positioned within the cavity.
7. A space heating apparatus as claimed in any preceding claim wherein the source of air from outside the combustion chamber is a source of air from a rear face of the heater.
8. A space heating apparatus as claimed in any one of claims 1 to 6 wherein the heater further comprises a fire bed or fire grate supported above a floor of the heater and the source of air from outside the combustion chamber is a source of air from below the fire bed or fire grate.
9. A space heating apparatus as claimed in any preceding claim further comprising an oven cavity.
10. A space heating apparatus substantially as herein described with reference to the accompanying drawings.