IE54023B1 - Improvements in and relating to room heating apparatus - Google Patents

Abstract

Room heating apparatus adapted to be located in and to seal the entrance to a conventional open fireplace, and comprising an adjustable valve (6) enabling the flow of air through the apparatus to the fire zone to be regulated, and an air duct system (15a, 15c) within the apparatus enabling air to enter the apparatus from the room in which the fireplace is located and, without entering the fire zone, to be heated in the apparatus before being returned to the room. The apparatus enables the rate of combustion of fuel in the fireplace to be controlled and enables fuel to be converted into heat in an efficient manner. The apparatus may also have a back water boiler (10) and a thermostatic control mechanism (not shown).

Description

The present invention relates to fireplaces and provides roam heating apparatus adapted to be fitted to an open fronted fireplace, canprising a substantially planar panel structure adapted to be fitted across the front of the fixeplaas opening and including: (a) a door, vhich, when open, allows solid fuel to be fed from the rocm throu^i the apparatus to the fireplace, (b) valve means for allowing a regulatable flow of air from the roan throu$t the apparatus to the fireplace, (c) an air duct system allowing air fran the roan to be heated without entering the fireplace and then returned to the room, and (d) an adjustable baffle projecting rearwerdly from the panel structure for varying the sire of the entrance from the fireplace to the flue.

Advantageously, the valve means enabling the flow of air to be regulated aonprisee a spin valve located in the lower part of the apparatus. The spin valve is ideally located in a door providing access to a fireplace ashpan beneath the grate.

Preferably, the duct system conprises a generally rectangular systen of ducts including horizontally disposed lower end ipper ducts adjacent the bottom and top of the apparatus, the upper and lower ducts being joined together at their ends ty two vertically disposed ducts, one at each side of the apparatus.

In a particular construction according to the invoition, the planar structure includes two castings, bolted or otherwise secured together to form a unit, the front casting having on its rear side adjacent its periphery a pair of mutually parallel U-shaped channel elements to receive the projecting linte of a continuous U-shaped channel inenter ai the rear casting and thereby to form a continuous duct within and adjacent the top, sides and lower region of the planar structure.

The invention will hereinafter be described more particularly with reference to the accaipanying drawings which illustrate, by way of exanple only, a preferred embodiment and a modification thereof.

In the drawings: Figure 1 is a front elevation of a fireplace apparatus according to the invention; Figure 2 is a sectional side elevatiai on line II-II of Figure 1 showing the apparatus in the entrance to a fireplace which includes a firegrate and back boiler; Figure 3 is a sectional plan view at line III-III of Figure 1, certain parts being omitted for the sake of clarity, again showing the apparatus in the entranas to a fireplace vhieh includes a firegrate and back boiler; Figures 4, 5, 6 and 7 are partial sectional plan views on lines IV-IV, V-V, VI-VI and VII-VII respectively, of Figure 1; and - 3 Figure 3 i» a partially cut away front elevation of a modified apparatus.

Referring to the drawings, and initially to Figures 1, 2 and 3 the fireplace apparatus comprises a front casting 1 and a rear casting 2, connected together to form a unit.

The front casting 1 has three recesses in which are located (a) a rectangular panel 3 having a series of apertures 29, (b) a glass door 4 providing access to the fireplace and grate 7 through a rectangular aperture 8 in the front casting 1, and (c) a door 5 providing access to the ashpan below the grate 7. In the door 5 is a manually adjustable spin valve 6.

The front casting 1 has a pair of U-shaped channel elements 12 which extend around the casting 1 adjacent its perimeter and into which project and are secured the ends of limbs 13 of a generally U-shaped channel member integral with the rear casting 2.

The U-shaped channel member of the rear casting 2 co-operates with the U-shaped channel elements 12 of the front casting 1 to form a continuous air duct system within the apparatus, the duct system being generally rectangular when viewed in elevation and conprising a lower horizontal duct 15a, two vertical side ducts 15b and an upper horizontal duct 15c. - 4 The front casting 1 and rear casting 2 are bolted together, in the manner shown in Figure 4, the bolt 16 passing through the front casting 1 and engaging the base 13a of the U-shaped channel member of the rear casting 2. The castings 1 and 2 are also bolted together by bolts 31, as shown in Figures 2 and 7.

Air inlets (not shown) to the duet system are provided at each end of the lower duct 15a and an outlet 17 is provided in the upper duct 15c, the outlet 17 being co-incident with and co-operating with the apertures 29 in the panel 3.

The air when heated in the lower duct 15a flows upwardly through the vertical side ducts 15b to the upper horizontal duct 15c from where it emerges into the room through the outlet 17 and apertures 29.

Thus the apparatus by conduction and convection heats and circulates air in the room. If desired, an electrically powered fan (not shown) may be provided to enhance the flow of air through the duct system.

Figures 2 and 3 show the apparatus in a fireplace which has a back boiler 10 defined by side panels 10a, a rear panel 10b, a transverse panel 10c, a water inlet lOd and water outlet lOe.

An adjustable baffle 18 (see Figure 2) is supported by a cradled pivot connection 24 on one of the 54(ί 23 - 5 rearwardly extending lipa 2a of the rear casting 2.

Also supported on each lip 2a is a fixing bracket 9 which can be tightened against the fireplace lintel 20. Connected to the rear of the upper transverse channel of the rear casting 2 are brackets (not shown) for supporting a plate (not shown) which acts as a heat sink and protects the lintel 20 from overheating. The lower part of the duct system is similarly protected.

The apparatus is installed by locating it in the fireplace entrance and then pushing it back until (see Figure 3) the backwardly extending lips 2a of tha rear casting 2 contact the forward edges 19 of the back boiler side panels 10a. The bottom and side edges of the apparatus are then sealed using fire cement. The glass door 4 is then opened and the fixing brackets 9 are swung around their pivot points so that their free ends engage the rear of the lintel 20. Bracket nuts 21 are then tightened to hold the apparatus in position. The top edge is then sealed by filling the space between the front casting 1, duct system 3 and lintel 20 with fire cement. The sealing not only increases the efficiency of the apparatus but also prevents the entry into the room of dust, smoke and fumes from the fire rone. Unwanted draughts are also eliminated. - 6 When the apparatus is in position, the baffle 18 is adjusted to an appropriate setting to restrict loss of heat. The baffle 18 may be moved from the position shown, to any of the three other positions indicated by dotted lines in Figure 2.

The baffle 18 is fixed in position by engagement of one of the eyes 22 of the baffle arm 23 with a stop pin 30 fixed to the lip 2a.

The glass door 4 can be opened by latch 14 (see 10 Figures 1 and 6) and ia hinged by hinge 11 so that it can be swung through a full lStf and so that it may easily be detached.

Below the grate 7 ia an ashpan (not shown).

Accese to the ashpan is via door 5 which has a handle 5a.

In operation, the glass door 4 is opened, and coal, turf or othar solid fuel is loaded onto the grate. When the fire is lighting, the glass door 4 is closed and the spin valve 6 is opened fully. Air is drawn into the fireplace through the epin valve 6. When a good blaze has been established, if it is desired to sit in front of an open fire, the glass door 4 may be opened. Alternatively, the glass door 4 may be left closed and the spin valve 6 set to give the desired rate of burning. When the glass door 4 is closed, the room is 34023 - 7 heated primarily by convected air flow through th· duct system and also by heat radiating from the fire through the glass door 4 and from the apparatus. When the glass door 4 is shut it is possible to regulate the air flow through the spin valve 6 and thereby to control the consumption of fuel and the temperature in the room and of the water in the bach boiler 10.

In the closed door mode, the fan (if provided) is switched on and the spin valve 6 is left partially open. Room air enters the lower duct 15a via the inlets (not shown). The air is heated in the lower duct 15a. The heated air rises through the ducts 15b where the air absorbs further heat before being returned to the room via outlet 17 and apertures 29.

IS It is generally unsafe to leave a fire in a conventional open fireplace unattended for a long period of time (i.e. overnight). Using an apparatus according to the invention, the fire may be left burning at night by closing the spin valve 6 (or thermostat when fitted). To enable the grate 7 to ba stacked with sufficient fuel to last through the night, the grate 7 has a vertical grate front 7a which is somewhat higher than that provided in a conventional fireplace. The glass door 4 is then closed and the adjustable spin valve 6 set for the minimum flow of primary air. - 8 enabling sufficient primary air to enter the fireplace to keep the fire smouldering but not to allow the fire to blaze. The fan (if provided) is switched off. As the fire smoulders, very little heat goes up the chimney or is emitted as radiant heat; most of the heat is transferred to room air passing through the duct system by natural circulation, and in this way the room is kept warm. In the morning the spin valve is reopened and the fire blazes almost immediately. Unattended burning times of ten to twelve hours can be achieved using an 1© apparatus according to the invention.

Figure 8 illustrates a thermostatic control mechanism for the primary air flow. λ primary air inlet 25 is provided at the bottom of the left hand side of the front casting 2. The thermostatic control mechanism comprises a lever arm 27 having a fulcrum or pivot point at its upper end, an effort point midway along its length, and a load point at its lower end.

The position of the fulcrum is set by the screw adjustment 28. A sensor 29, one end of which projects into the fire, is connected at its other end to the lever arm 27, the point of connection constituting the load point. When the sensor expands or contracts the lever swings clockwise or anticlockwise (es seen in Figure 8), about its fulcrum point. This movement of 4 0 2 3 - 9 the lever arm admits more or lee· air into the air inlet 25. The thermostatic control mechanism may be adjusted by adjusting the fulcrum point by means of screw adjustment 28.

The fuel efficiency of a fire provided with an apparatus according to the invention is much greater than the fuel efficiency of an open fire. The apparatus enables the fuel burning rate to be controlled, and reduces the demand for combustion air.

Typical open firee remove approximately two hundred and forty cubic metres of air per hour from a room, whereas an apparatus according to the invention requires approximately twenty five per cent of that volume of air for efficient working.

Fires in open fireplaces are approximately fifteen per cent efficient due to heat loss going tp the chimney. By the use of an apparatus according to the invention, the fuel efficiency could be increased to more than sixty five per cent.

The burning rate for coal may be from one kilogramme to two kilogrammes per hour and this could - 10 provide sufficient heat for an indirect domestic hot water cylinder feeding six radiators.

The apparatus shown in Figures 1 to 7 weighs about forty five kilograms and is designed for a fireplace 0.4 metres to 0.46 metres wide and 0.56 metres high.

Claims (10)

1. qjJMS·.

1. Room heating apparatus adapted to be fitted to an open fronted fireplace, apprising a substantially planar panel structure adapted to be fitted across the front of the fireplace 5 opening and including: (a) a door, vftiich, when open, allows solid fuel to be fed from the roan through the apparatus to the fireplace, (b) valve means for allowing a regulatable flow of air frcm the roan through the apparatus to the fireplace, (c) an air duct system allowing air from the room to be heated without 10 altering the fireplace and then returned to the room, and (d) an adjustable baffle projecting rearwardly fran the panel structure for varying the size of the entrance from the fireplace to the flue.

2. Apparatus as claimed in Claim 1, in which the 15 valve means enabling the flow of air to be regulated aonprises a spin valve located in the lo^mr part of the apparatus.

3. Apparatus as claimed in Claim 2, in which the spin valve is located in a door providing access to a 20 fireplace ashpan beneath the grate,

4. Apparatus as claimed in Claim 2 or Claim 3 in which the spin valve is manually operable.

5. Apparatus as claimed in any one of the preceding claims, in which the duct means comprises a generally 25 rectangular system of ducts including horizontally disposed lower and upper ducts adjacent the bottom and - 12 tcp of the apparatus, the upper and lower ducts being joined together at their ends ty two vertically disposed ducts, cr» at each side of the apparatus.

6. Apparatus as claimed in Claim 5, in uhich an air 5 inlet is provided at each end of the lower duct and an air outlet is provided intermediate the ends of the upper duct.

7. Apparatus as claimed in any one of the preceding claims, in which the planar structure includes tuo castings, bolted or otherwise secured together to form a unit, the 10 front casting having on its rear side adjacent its periphery a pair of mutually parallel U-shaped channel elements to receive the projecting limbs of a continuous U-shaped channel mother cn the rear casting and thereby to fans a continuous duct within and adjacent the top, sides and lower 15 regicn of ths planar structure.

8. Apparatus as claimed in any one of the preceding claims, in which fixing brackets are provided for securing the apparatus in position in the fireplace entrance, the fixing brackets being pivotally mounted on the apparatus, so 20 that each bracket my be swung into a position in uhich it engages the rear of the fireplace lintel and thereby secures the apparatus in position.

9. Apparatus as claimed in any aie of the preceding claim including means cn the apparatus for 25 protecting the fireplace lintel fran overheating. 54033 - 13 10. Apparatus as claimed in Claim 7, including means for protecting the lower part of the duct system from overheating. 11. Apparatus as elaimsd in any one of the preceding 5 claims, including a fan for driving air through the duct system. 12. Apparatus as claimed in Claim 1 or any of Claims 4 to 11 as dependent on Claim 1, in which the adjustable flow valve is thermostatically controlled.

10. 13. Room heating apparatus substantially as herein described with reference to and as illustrated in Figures 1 to 7 or Figures 1 to 7 as modified by Figure 8 of the accompanying drawings.