The wood kindling unit which must secure a unproblematic kindling of solid fuel by means of a grate arrangement is known fx from US patent 2004173206 and WO patent 2004079266, but these patents does not have the purpose to be used in wood burning stove with closed combustion chamber and they do not have the purpose to secure a directional supply of air for combustion, resulting in a reduction of the discharge of polluting chimney gas particle.

In principal the kindling of solid fuel in wood burning stove is problematic because air- and the ash grate conventionally placement in the bottom of the burn chamber does not consider an optimal supply of primary air to the combustion. Either because the air is blocked of the solid fuel which is about to be kindled, or if the solid fuel is placed inexpedient in respect to the ash grate you can unintended have too much supply of primary air. When blocking the air supply it becomes difficult to kindle the wood because of the lack of primary air for combustion, which leads to a much too low temperature in the burn chamber for the flammable gases to be released and set on fire. When the supply of primary air for combustion is too heavy it will result in an unintended cooling of the fuel and the burn chamber, which prevents an ignition of the fuel because of cooling and because the flames are blown away from the fuel.

In consequence of said problem it is often necessary to supply the fire medium, fx with newspapers, firelighters or lighter fuel, a number of times during the kindling procedure before the heat generation from the fuel is sufficient for the flammable gases to be released in adequate amount, leading to an ignition of the fuel and an autonomous combustion, without the need of supplying further fire media. From the initiation of the kindling procedure until the ignition of the fuel takes place the combustion is incomplete, in consequence hereof soothed polluted gases is discharged containing health damaging particles, among other PAH- compound, tar- compounds and dioxin.

The object of the present invention is to provide a wood kindling unit, which can ensure a quickly kindling of the fuel according to a standardized kindling procedure preventing said problems related to the kindling and pollution.

This is done by placing the wood kindling unit on top of the ash grate in the combustion chamber, where after the fuel, desired to ignite, is placed on the wood kindling units grate.

After ignition of a fire medium under the fuel a directional and free supply of air for combustion to the fuel is provided by the wood kindling unit and further the wood kindling unit ensures that the flames released by the fire medium touches the surface of the fuels after a predetermined flow pattern. In this way the heat energy released by the fire medium is concentrated and provides a forced heating of the fuel and the oven room resulting in the ignition of the fuel. When the ignition of the fuel occurs the combustion becomes autonomous at so high temperature, that the discharge of polluted chimney gas particle is eliminated or reduced considerable.

The invention consist of a insert to a wood burning stove, where the insert besides a grate includes a horizontal bottom plate, where the top side is connected to the horizontal lower edges of three vertical rectangular plates and where the two plates are considerable parallel to one mutual distance, corresponding to the extent of the third plate and where the three vertical plates are connected considerable in the vertical plate units and where a considerable horizontal grate arrangement is connecting to the 2 parallel plates and placed over the level of the horizontal bottom plate, in such a way, that at a cavity is crated between the bottom plate and the grate arrangement and where there are openings for ventilation in the plates, placed over the grate arrangement and where den intermediate vertical plate at least has one in the considerably horizontal guiding plate at the top and a arrangement to keep the vertical distance towards the middle of the insert.

The wood kindling unit is in full constructed in such a way that the intake of heat energy from the fire medium and the air for combustion is directional. In this way it becomes possible to kindle the fuel, leading to a quickly heating of the fuel surface and oven room, resulting in a quickly development of flammable gases.

The invention provides a placing of the fuel on a grate arrangement resulting in a free inflow of heat energy from the fire medium and the primary air for combustion via the cavity for the fuel. The bottom plate is constructed so that it is shielding for free inflow of cooling primary air on the fuel and provides, under the influence of thermodynamically conditions in the burn chamber, that heated air/gases is guided towards the cavity which speed up the heating of the fuel. The ventilation holes shown on the vertical site plates has been constructed in such a way that they provides for the supply of heated

secondary air to the fuel from the oven room, which speed up the heating of the fuel. The space holder arrangement of the hindmost vertical site plate is constructed, so as to provide for the heat energy released from the fire medium is swept over on a relatively big surface on the fuel, with high velocity. The leading plate is constructed in such a manner so as to ensure that the heat energy from the fire medium is guided towards the fuel which is placed high in the burn chamber and ignites said fuel. Between the bottom plate and the grate arrangement you have a cavity where the fire medium can be placed.

DRAWING

Shown details on the figure for a insert to a woodburning stove, with numbers of reference:

1. bottom plate

2. rectangular plates

3. ventilation openings in the plates

4. horizontal guiding plate

5. distance holder arrangement 6. grate arrangement

7. cavity between the bottom plate and grate arrangement

Insert to a woodburning stove, where the insert includes a grate, a horizontal bottom plate 1 said top side is connecting to three vertical rectangular plates 2 horizontal lower edges and where the two plates is in the considerable parallel to a mutual distance corresponding to the third plates extent and where the three vertical plates are connected considerably in the vertical plates and where a considerably horizontal grate arrangement 6 is connecting to the two parallel plates 2 and placed over the level of the horizontal bottom plate 1, in this way, a cavity 7 is created between the bottom plate and grate arrangement and where there are ventilation openings 3 in plates 2 placed over the grate arrangement 6 and where the intermediate vertical plate has at least one in the considerable horizontal guiding plate 4 at the top and a vertical space arrangement towards the insert middle.