GB2036954A

GB2036954A - Improvements in fire places

Info

Publication number: GB2036954A
Application number: GB7939053A
Authority: GB
Original assignee: Pynford Ltd
Current assignee: Pynford Ltd
Priority date: 1978-11-13
Filing date: 1979-11-12
Publication date: 1980-07-02
Also published as: GB2036954B

Abstract

A false floor 6 is fitted on the hearth of a domestic fireplace and supports the grate 13. The false floor 6 covers a chamber into which an air supply duct 12 discharges. The air is preheated in the chamber, passes out of the chamber through openings 10 in a front wall of the chamber, and in through openings (16, Fig. 1) in a damper 15 to the underside of the grate 13 to nourish the combustion of fuel on the fire. <IMAGE>

Description

SPECIFICATION Improvements in fire places A coventional domestic fire has a grate, often in the form of a basket, on which the coal or other fuel is burnt, and a damper having variable openings through which air passes from the room into the underside of the grate to nourish the combustion of the fuel. Air is continuously drawn in through the damper owing to the convection of the hot gaseous combustion products from the grate up the chimney. This in turn draws air into the room through ill-fitting doors and windows and leads to unpleasant cold draughts. If the doors and windows are well-fitting, particuarly when the windows are doubie-glazed, insufficient air can be drawn from the room through the damper and grate and up the chimney and as a result the fire may "smoke" into the room.One solution to this problem has been to provide an under hearth air supply in the form of a pipe which leads from outside the building and terminates with its open end beneath the grate. This arrangement is also not entirely satisfactory as large amounts of cold air are drawn up through the grate causing the fuel to burn unnecessarily fiercely, with consequential extra fuel costs.

In accordance with the present invention, a domestic fire place is provided with a grate and damper which has openings through which air can pass from the room space to the underside of the grate, the grate being mounted spaced above a false floor, preferably made of metal, which is sealed to the hearth to provide, beneath the false floor, a chamber bounded by a front wall formed with openings through which air can pass from the chamber into the room space; and an air duct which extends from outside the room and discharges air into the chamber; the arrangement being such that the air discharged from the duct is preheated in the chamber from the false floor, passes out through the openings in the front wall of the chamber, and in through the damper to nourish the combustion of fuel on the grate.

With this arrangement the grate is provided with a gentle supply of preheated combustion air which is not drawn right through the room and which can be controlled by the coventional damper control.

In a simple construction the false floor is a metal plate shaped to conform to the plan shape of a fireback and sealed to it by refractory cement.

The plate may be provided at its edge with a downwardly projecting skirt by means of which the plate is supported on the hearth. The front wall is then preferably provided by a front part of the skirt. Most simply, the grate is a fire basket standing on the false floor with a damper also standing on the false floor surrounding' the front of the basket.

An example of a fire place in accordance with the invention is illustrated in the accompanying drawings, in which: Figure 1 is a perspective view; and, Figure 2 is a central vertical section through the fire place from front to back.

The illustrated fire place has a conventional hearth 3 and fireback 4, which leads up to a flue.

An exposed surround facing into the room is shown tiled at 5.

The hearth is provided with a raised false floor formed by a fabrication of a steel plate 6 with a steel skirt 7 which extends downwardly from the edge of the plate 6 and rests on the hearth 3. The shape of the plate conforms generally to that of the fireback except for laterally projecting wings 8 at its front edge which overlap the surround of the fire place. The fabrication can be readily fitted into a conventional fireback of suitable nominal size and sealed to the hearth and fireback by fireproof cement 9 packed behind the skirt 7. A front portion 7A of the skirt 7, extending downwardly from the slightly convex front edge of the plate 6, is formed with a series of holes 10 which lead from the room space into a chamber 11 formed beneath the plate 6. An air supply duct 12 leads from an external source of air, under the room floor, and opens into the bottom of the chamber 11.

Instead of standing directly on the hearth 3, as would be conventional, a grate 13 in the form of a conventional fire basket stands by means of its four legs 14 on the plate 6 within the fireback. The front of the grate 13 is shielded by a conventional damper 1 5 formed with a number of slots 1 6 which can be opened and closed to a controlled degree upon movement of a slide 17, by manipulation of a knob 1 8, to bring corresponding slots in the slide 17 into or out of alignment with the slots 1 6.

In use the fire is made on the grate 13 and when lit the fire is nourished by air which is drawn by convection in through the openings 1 6 in the damper 1 5 to the underside of the grate 13. This air in turn is drawn through the duct 12, the chamber 11, and the holes 10 so that the air flow follows the path indicated by the arrows. It will be appreciated that the cold air entering the chamber 11 from the duct 12 impinges on the underside of the plate 6, which will be heated by radiation from the fire and by supporting hot ashes, so that the air entering the room space through the openings 10 and supplied to the fire will be prewarmed. A plentiful supply of preheated combustion air is thus provided to the fire without cold air being drawn from remote parts of the room space.

1. A domestic fire place provided with a grate and damper which has openings through which air can pass from the room space to the underside of the grate, the grate being mounted spaced above a false floor which is sealed to the hearth to provide, beneath the false floor a chamber bounded by a front wall formed with openings through which air can pass from the chamber into the room space; and an air duct which extends from outside the room and discharges air into the chamber; the arrangement being such that the air discharged from the duct is preheated in the

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in fire places A coventional domestic fire has a grate, often in the form of a basket, on which the coal or other fuel is burnt, and a damper having variable openings through which air passes from the room into the underside of the grate to nourish the combustion of the fuel. Air is continuously drawn in through the damper owing to the convection of the hot gaseous combustion products from the grate up the chimney. This in turn draws air into the room through ill-fitting doors and windows and leads to unpleasant cold draughts. If the doors and windows are well-fitting, particuarly when the windows are doubie-glazed, insufficient air can be drawn from the room through the damper and grate and up the chimney and as a result the fire may "smoke" into the room.One solution to this problem has been to provide an under hearth air supply in the form of a pipe which leads from outside the building and terminates with its open end beneath the grate. This arrangement is also not entirely satisfactory as large amounts of cold air are drawn up through the grate causing the fuel to burn unnecessarily fiercely, with consequential extra fuel costs. In accordance with the present invention, a domestic fire place is provided with a grate and damper which has openings through which air can pass from the room space to the underside of the grate, the grate being mounted spaced above a false floor, preferably made of metal, which is sealed to the hearth to provide, beneath the false floor, a chamber bounded by a front wall formed with openings through which air can pass from the chamber into the room space; and an air duct which extends from outside the room and discharges air into the chamber; the arrangement being such that the air discharged from the duct is preheated in the chamber from the false floor, passes out through the openings in the front wall of the chamber, and in through the damper to nourish the combustion of fuel on the grate. With this arrangement the grate is provided with a gentle supply of preheated combustion air which is not drawn right through the room and which can be controlled by the coventional damper control. In a simple construction the false floor is a metal plate shaped to conform to the plan shape of a fireback and sealed to it by refractory cement. The plate may be provided at its edge with a downwardly projecting skirt by means of which the plate is supported on the hearth. The front wall is then preferably provided by a front part of the skirt. Most simply, the grate is a fire basket standing on the false floor with a damper also standing on the false floor surrounding' the front of the basket. An example of a fire place in accordance with the invention is illustrated in the accompanying drawings, in which: Figure 1 is a perspective view; and, Figure 2 is a central vertical section through the fire place from front to back. The illustrated fire place has a conventional hearth 3 and fireback 4, which leads up to a flue. An exposed surround facing into the room is shown tiled at 5. The hearth is provided with a raised false floor formed by a fabrication of a steel plate 6 with a steel skirt 7 which extends downwardly from the edge of the plate 6 and rests on the hearth 3. The shape of the plate conforms generally to that of the fireback except for laterally projecting wings 8 at its front edge which overlap the surround of the fire place. The fabrication can be readily fitted into a conventional fireback of suitable nominal size and sealed to the hearth and fireback by fireproof cement 9 packed behind the skirt 7. A front portion 7A of the skirt 7, extending downwardly from the slightly convex front edge of the plate 6, is formed with a series of holes 10 which lead from the room space into a chamber 11 formed beneath the plate 6. An air supply duct 12 leads from an external source of air, under the room floor, and opens into the bottom of the chamber 11. Instead of standing directly on the hearth 3, as would be conventional, a grate 13 in the form of a conventional fire basket stands by means of its four legs 14 on the plate 6 within the fireback. The front of the grate 13 is shielded by a conventional damper 1 5 formed with a number of slots 1 6 which can be opened and closed to a controlled degree upon movement of a slide 17, by manipulation of a knob 1 8, to bring corresponding slots in the slide 17 into or out of alignment with the slots 1 6. In use the fire is made on the grate 13 and when lit the fire is nourished by air which is drawn by convection in through the openings 1 6 in the damper 1 5 to the underside of the grate 13. This air in turn is drawn through the duct 12, the chamber 11, and the holes 10 so that the air flow follows the path indicated by the arrows. It will be appreciated that the cold air entering the chamber 11 from the duct 12 impinges on the underside of the plate 6, which will be heated by radiation from the fire and by supporting hot ashes, so that the air entering the room space through the openings 10 and supplied to the fire will be prewarmed. A plentiful supply of preheated combustion air is thus provided to the fire without cold air being drawn from remote parts of the room space. CLAIMS

1. A domestic fire place provided with a grate and damper which has openings through which air can pass from the room space to the underside of the grate, the grate being mounted spaced above a false floor which is sealed to the hearth to provide, beneath the false floor a chamber bounded by a front wall formed with openings through which air can pass from the chamber into the room space; and an air duct which extends from outside the room and discharges air into the chamber; the arrangement being such that the air discharged from the duct is preheated in the chamberfrnm the false floor, passes out through the openings in the front wall of the chamber, and in through the damper to nourish the combustion of fuel on the grate.

2. A fire place according to claim 1, in which the false floor is a metal plate shaped to conform substantially to the plan shape of a fireback and sealed thereto by refractory cement.

3. A fire place according to claim 2, in which the plate is provided at its edge with a downwardly projecting skirt by means of which the plate is supported on the hearth.

4. A fire place according to claim 3, in which the front wall is provided by a front part of the skirt.

5. A fire place according to claim 4, in which the front edge of the plate and the front wall are outwardly convex.

6. A fire place according to any one of the preceding claims, in which the air duct terminates with an end pointing upwards beneath the false floor.

7. A fire place according to any one of the preceding claims, in which the grate is a fire basket standing on the false floor with a damper also standing on the false floor surrounding the front of the basket.

8. A fire place according to claim 1, substantially as described with reference to the accompanying drawings.