IES86857B2 - Air control means for a batch fuel fed stove - Google Patents

Abstract

A batch fuel fed stove (10), is operable to burn different types of solid fuels. The stove has channels or conduits (38) adapted to deliver primary air for the combustion of wood or timber fuel and separately for delivering primary air for the combustion of other fuels. A further channel or conduit is provided for delivering secondary air for combustion. The stove has a single air control means (34) operable to control, vary and close off the two primary air supplies and the secondary air supply. The single air control means (34) comprises a movable elongate plate cover operable to open and close air openings in a plenum box (38) supplying air to the air supply channels or conduits. The plate cover (34 is provided with a pivot point (48) about which the plate cover can pivot to open and close the air openings in the plenum box (38) and also is provided with a slot (46) engaged in a sliding manner with the pivot point (48) to provide an additional plane of movement to open and close the air openings in the plenum box. <Figure 1>

Description

AIR CONTROL MEANS FOR A BATCH FUEL FED STOVE The present invention relates to a batch fuel fed stove, in particular to a solid fuel stove manufactured from cast iron or steel. More particularly, the invention relates to control of an air management system for a batch fuel fed stove.

The burning of solid fuels in stoves is becoming more stringent and is subject to various pollution and clean air regulations in very many countries and jurisdictions. It is well known to have wood burning stoves and also to have stoves which burn bituminous or fossil fuels such as coal, coke, turf and various smokeless fuels. The difficulty that arises is that in order to have efficient burning of wood and timber, the bulk of air to provide for combustion should be substantially delivered from the top of the fuel, whereas the other fuels burn more efficiently when the bulk of the combustion air is substantially fed from underneath the fuel through a grate. Major problems arise when a user attempts to burn bituminous fuels in a wood burning stove and vice versa when burning wood in a stove for other fuels.

The object of the invention is to alleviate the above disadvantages.

The present invention provides a batch fuel fed stove which is operable to burn different types of solid fuels, the stove having channels or conduits adapted to deliver primary air for the combustion of wood or timber fuel and separately for delivering primary air for the combustion of other fuels together with a further channel or conduit for delivering secondary air for combustion, the stove further comprising a single air control means operable to control, vary and close off the two primary air supplies and the secondary air supply.

Advantageously, the single air control means comprises a movable elongate plate cover operable to open and close air openings in a plenum base supplying air to the air supply channels or conduits.

Advantageously, the plate cover is provided with a pivot point about which the plate cover can pivot to open and close the air openings in the plenum base.

Preferably, the plate cover is provided with a slot engaged in a sliding manner with the pivot point to provide an additional plane of movement to open and close the air openings in the plenum base.

Conveniently, the plate cover is provided with an elongate handle for use by a user to manipulate the plate cover and open and close air openings in the plenum base as desired to regulate the flow of primary air and secondary air as required.

Optionally, the air control means of the stove is adapted to provide tertiary air in addition to primary and secondary air.

By “primary air” is meant air that is supplied to provide for combustion of fuel in the stove thereby providing for primary combustion.

By “secondary air” is meant air that is supplied to provide for combustion of the byproducts resulting from primary combustion thereby providing secondary combustion.

By “tertiary air” is meant air that is supplied to provide for combustion of the secondary byproducts of primary and secondary combustion thereby providing tertiary combustion.

The invention will hereinafter be more particularly described with reference to the accompanying drawings what show, by way of example only, one embodiment of a stove according to the invention.

In the drawings: Figure 1 is a perspective view of the stove; Figure 2 is a cross-sectional side view through the stove and the air conduit mechanism at the base of the stove; Figure 3 is an underneath cross-sectional plan view of the air control conduit mechanism detecting the movement capabilities of a chamber control of the air control means to the stove; Figure 4 is a cross-sectional plan view of the air control means showing the start-up setting of the damper control; Figure 5 is a cross-sectional plan view of the air control means showing the wood burning setting of the chamber control; Figure 6 is a cross-sectional plan view of the air control means showing the coal burning setting of the chamber control; Figure 7 is a cross-sectional plan view of air control means showing the secondary air setting of the chamber control; and Figure 8 is a cross-sectional plan view of the air control means showing the shut down setting of the chamber.

Referring to the drawings and the specific embodiment shown therein, stove 10 is of steel construction and has two side walls 11, a front wall 12, a rear wall 13, a base 14 and a top 15. A flue 16 may be connected to the top 15 (Figure 1) or the rear wall 13 (Figure 2). A door 20 is pivotally attached to the front wall 12 and can be opened and closed using handle 22. The door is provided with a glass window 24 through which a fire burning on grate 26 in the stove is visible. Secondary air passes over the inside surface of the glass window to keep it clean.

The air control means of the stove is operated by a handle 30 located beneath ash pan 28. Movement of the handle 30 transversely and laterally relative to the front wall 12 operates air control plate 34 to open and close various orifices 36 so as to control the flow of primary and secondary air from the plenum base 38 to the air supply channels and conduits 40 in the stove.

The operation of the air control means will now be described with reference to Figures 3 to 8. In Figure 3, air control plate 34 has an orifice 35 which is located over a solid panel of metal in the plenum base 38, thereby closing off air inlet 42 (the coal burning air inlet) and air inlet 44 (the wood burning air inlet). The handle 30 allows the control plate 34 to be moved laterally by means of slot 46 moving relative to the fixed pivot pin 48 and also to move pivotally relating to the pivot pin 48.

In the start up setting shown in Figure 4, the coal burning air inlet 42 is partially open and the wood burning air inlet 44 is also partially open because the orifice 35 is located between the two inlets 42 and 44.

In the wood burning setting as shown in Figure 5, the wood burning air inlet 44 is open as it is in line with the orifice 35 of the air control plate 34 and the air inlet 42 is closed.

In the coal burning setting as shown in Figure 6, the coal burning air inlet 42 is open and the air inlet 44 is closed.

In Figure 7 the secondary air control portion 45 of the wood burning air inlet 44 is open as the orifice 35 is only located over the portion 45.

Finally, the shut down setting is shown in Figure 8 with all air inlets 42, 44 and portion 45 fully closed. This setting is the same setting as shown in Figure 3 from the other plan view.

In the batch fuel fed stove as shown in Figure 1, there is one air control means controlling both primary and secondary air. When in the centre it will provide 50% secondary and 50% primary, when pushed in a first direction the percentage primary will increase and the percentage secondary reduce. When pushed fully in the first direction the air supply is 100% primary air and 0% secondary air.

When pushed in a second direction the percentage secondary air will increase and the percentage primary air reduce.

When pushed fully in the second direction the air supply is 100% secondary air and 0% primary air.

When burning wood, the air control means should always be in the centre or moved slightly in the second direction from the centre. On the initial light up, the handle 30 should be marginally in the second direction centre and pushed fully in providing some under grate air for the fire bed to become established.

When the fire has established, the air control means should be pushed in the second direction to provide for a more efficient burn on wood and then pulled forwards to slow the burn rate as desired.

If necessary to provide a little primary while burning wood, the air control means can be moved a little towards the centre to provide a little primary to maintain the fire.

When burning coal, the air control means should always be moved in the first direction from the centre. On initial light up the handle 30 should be pushed slightly in the first direction from the centre and pushed fully in providing under grate air fully while still providing some window - wash air to maintain a clear viewing glass.

When the fire has established, the air control means should be pushed fully in the first direction for most efficient burning of smokeless coals and then pulled towards the centre to slow the burn rate as desired.

The stove shown in the drawings can be varied in many ways without detracting from the invention. No limitation is intended to the materials used to manufacture the stove, the type, the design and number of doors to the stove and the shape and dimensions of the stove. These can be altered to suit any particular requirement.

It is to be understood that the invention is not limited to the specific details described herein and which are given by way of example only and that various modifications and alterations are possible without departing from the scope of the invention.

Claims (6)

CLAIMS:

1. A batch fuel fed stove which is operable to burn different types of solid fuels, the stove having channels or conduits adapted to deliver primary air for the combustion of wood or timber fuel and separately for delivering primary air for the combustion of other fuels together with a further channel or conduit for delivering secondary air for combustion, the stove further comprising a single air control means operable to control, vary and close off the two primary air supplies and the secondary air supply.

2. A batch fuel fed stove as claimed in Claim 1, in which the single air control means comprises a movable elongate plate cover operable to open and close air openings in a plenum base supplying air to the air supply channels or conduits; in which the plate cover is provided with a pivot point about which the plate cover can pivot to open and close the air openings in the plenum base; in which the plate cover is provided with a slot engaged in a sliding manner with the pivot point to provide an additional plane of movement to open and close the air openings in the plenum base; and in which the plate cover is provided with an elongate handle for use by a user to manipulate the piate cover and open and close air openings in the plenum base as desired to regulate the flow of primary air and secondary air as required.

3. A batch fuel fed stove as claimed in any one of the preceding claims, in which the air control means of the stove is adapted to provide tertiary air in addition to primary and secondary air.; by “primary air” is meant air that is supplied to provide for combustion of fuel in the stove thereby providing for primary combustion; by “secondary air” is meant air that is supplied to provide for combustion of the by-products resulting from primary combustion thereby providing secondary combustion; and by “tertiary air” is meant air that is supplied to provide for combustion of the secondary by-products of primary and secondary combustion thereby providing tertiary combustion; in which the stove is of steel construction and has two side walls, a front wall, a rear wall, a base and a top, a door is pivotally attached to the front wall and can be opened and closed using a handle, a grate for burning the fuel, the door is provided with a glass window through which a fire burning on the grate in the stove is visible, whereby during combustion, secondary air passes over the inside surface of the glass window to keep it clean; in which the air control means of the stove is operated by a handle located beneath an ash pan wherein movement of the handle transversely and laterally relative to the front wall operates an air control plate to open and close various orifices so as to control the flow of primary and secondary air from the plenum base to the air supply channels and conduits in the stove; in which air control plate has an orifice which is located over a solid panel of metal in the plenum base, thereby closing off coal burning air inlet and wood burning air inlet, the handle allowing the control plate to be moved laterally by means of a slot moving relative to a fixed pivot pin and also to move pivotally relating to the pivot pin; in which in the start-up setting the coal burning air inlet is partially open and the wood burning air inlet is also partially open as a result of the orifice being located between the two inlets whereby, in the wood burning setting the wood burning air inlet is open as it is in line with the orifice of the air control plate and the coal burning air inlet is closed and in the coal burning setting the coal burning air inlet is open and the air inlet is closed; and in which the secondary air control portion of the wood burning air inlet is open as the orifice is only located over the portion and in the shut down setting all air inlets and portion are fully closed.

4. A batch fuel fed stove as claimed in any one of the preceding claims, in which there is one air control means controlling both primary and secondary air; when in the centre it will provide 50% secondary and 50% primary, when pushed in a first direction the percentage primary will increase and the percentage secondary reduce, when pushed fully in the first direction the air supply is 100% primary air and 0% secondary air, when pushed in an opposite second direction, the percentage secondary air will increase and the percentage primary air reduce, and when pushed fully in the second direction the air supply is 100% secondary air and 0% primary air; in which when burning wood, the air control is always in the centre or moved slightly in the second direction from the centre, on the initial light up, the air control means is marginally in the second direction centre and pushed fully in providing some under grate air for the fire bed to become established and when the fire has established, the air control means is pushed in the second direction to provide for a more efficient burn on wood and then pulled forwards to slow the burn rate as desired and if necessary to provide a little primary while burning wood the control can be moved a little towards the centre to provide a little primary to maintain the fire; and in which when burning coal, the air control means is moved in the first direction from the centre, on initial light up the air control means is pushed slightly in the first direction from the centre and pushed fully in providing under grate air fully while still providing some window wash air to maintain a clear viewing glass, and when the fire has 5. Established, the air control means is pushed fully in the first direction for most efficient burning of smokeless coals and then pulled towards the centre to slow the burn rate as desired.

5. A batch fuel fed stove substantially as herein described with reference to and as

6. 10 shown in the accompanying drawings.