EP3081860A1 - Oven - Google Patents

Abstract

The invention relates to a furnace for heat generation, in particular wood burning stove, such as log burning stove or pellet stove, which comprises: a combustion chamber (2) having a rear wall (7) and two side walls (12e, 12f); an afterburner chamber (3), which is arranged below the combustion chamber (2), and a flue gas duct (6) for supplying flue gas from the combustion chamber (2) into the afterburner chamber (3), the flue gas duct (6) being arranged on the rear wall (7) of the combustion chamber (2) or on one of the side walls.

Description

FIELD OF THE INVENTION

The present invention relates generally to furnaces for heat generation, and more particularly to a furnace for generating heat with a post-combustion chamber.

BACKGROUND OF THE INVENTION

Generally, furnaces for heat generation are known which are particularly suitable for burning solid fuels such as wood, e.g. Logs or pellets, or other solid fuels are suitable. Such ovens are typically also used in living quarters, e.g. in the form of a stove, placed.

In general, there are in wood-burning stoves, which are placed like stoves in particular in living spaces, the desire to optimize the combustion by appropriate control of the air supply and thus, for example, to reduce the particulate matter pollution and the emission of nitrogen oxides.

It is known to improve combustion by providing a so-called after-burning chamber. So shows, for example EP 0 579 013 A1 a heating furnace with a secondary combustion chamber, which is arranged below a combustion chamber. Flue gas, which is formed in the combustion chamber during combustion, is passed through a flow channel, which is arranged in the bottom of the combustion chamber, from the combustion chamber down into the afterburner. The primary air flows above the flow channel into the combustion chamber.

A similar type has a combustion device that is in DE 10 2009 050 507 A1 is shown. The combustion device has a combustion chamber and a Nachbrennraum, wherein combustion chamber and Nachbrennraum are separated by a combustion grate. A primary air supply is arranged above the combustion grate. The flue gas is passed through the combustion grate in the afterburner.

The object of the present invention is to provide an improved furnace for heat generation, in particular a wood-burning stove, such as a log or pellet stove.

SUMMARY OF THE INVENTION

According to a first aspect, the present invention provides a furnace for heat generation, in particular a wood-burning stove, such as a log furnace or pellet stove, comprising: a combustion chamber having a back wall and two side walls, an afterburner chamber located below the combustion chamber, and a flue gas duct for delivery of flue gas from the combustion chamber in the secondary combustion chamber, wherein the flue gas channel is arranged on the rear wall of the combustion chamber or on one of the side walls.

Further aspects and features of the present invention will become apparent from the dependent claims, the accompanying drawings and the following description of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWING

• Fig. 1 ein Ausführungsbeispiel eines Holzofens in einer vertikalen Querschnittsseitenansicht veranschaulicht; und
• Fig. 2 den Holzofen von Fig.1 in einer vertikalen Querschnittsfrontansicht zeigt.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

• Fig. 1 an embodiment of a wood stove in a vertical cross-sectional side view illustrates; and
• Fig. 2 the wood stove of Fig.1 in a vertical cross-sectional front view.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the Fig. 1 to 2 an embodiment of a wood oven 1 in accordance with the present invention is illustrated. Before a detailed description follows first general explanations to the embodiments and their advantages.

The embodiments relate to a furnace for heat generation, which is designed to burn a solid fuel in a combustion chamber. In principle, all types of solid fuels are considered, which are made of biomass, such as pellets, wood chips, firewood, but also fuels such as brown, wood or hard coal and the like.

The further description also relates, in particular, without the present invention being restricted thereto, to a wood-burning stove, such as a wood-burning stove or a pellet stove, which is designed, for example, as a stove, tiled stove or the like and is typically set up in a living room.

In the exemplary embodiments, a furnace for generating heat, in particular a wood-burning stove, such as a log-burning stove or pellet stove, comprises a combustion chamber with a rear wall and two opposite side walls. Opposite the rear wall of the combustion chamber is typically closed on its front wall with an oven door.

The side and / or back wall of the furnace may be made of various materials typical of furnaces (e.g., sheet metal, cast iron, etc., as well as a cladding with firebricks or the like inside). The present invention is not limited to a particular material configuration of the back wall or the side wall.

In addition, the combustion chamber can also have any shape. The walls of the combustion chamber, that is, the front, rear and side walls may, viewed in a horizontal cross-section, lie on a quadrangle, square or rectangle, a triangle or another polygon. In principle, the combustion chamber can also have a round cross-section, e.g. circular or elliptical. In such embodiments, the rear wall, front wall and side walls are to be considered as corresponding portions of a continuous combustion chamber wall having a round horizontal cross section.

The furnace further comprises an afterburner chamber disposed below the combustion chamber and a flue gas passage for supplying flue gas from the combustion chamber to the reheat chamber, the flue gas passage being disposed on the rear wall of the combustion chamber and / or on one of the side walls. In the afterburning chamber and possibly also in the flue gas duct, the flue gas can continue to burn, as a result of which the total pollutant emissions of the furnace can be reduced.

The flue gas channel may extend over the entire width of the rear or side wall of the combustion chamber or extend over only a part of the rear or side wall. The flue gas channel may be formed by separate flue gas channel walls and / or partially or completely by areas of the rear or side walls of the combustion chamber and / or a housing of the furnace, which at least partially surrounds the combustion chamber.

The fact that the flue gas duct can divert the flue gas from the combustion chamber and leads into the afterburner chamber below the combustion chamber and can also be arranged outside the combustion chamber, the combustion chamber and the afterburner can be separated from each other.

The flue gas flow thus goes against gravity from the bottom up in the combustion chamber in the flue gas duct and then in the flue gas duct from top to bottom in the direction of gravity in the secondary combustion chamber located below the combustion chamber.

The afterburner chamber may have substantially the same horizontal cross section as the combustion chamber, but it may also be formed independently of the shape or independently of the cross section of the combustion chamber. The combustion chamber may be partially formed by walls of a housing of the furnace and / or it may be formed independently.

The primary air supply into the combustion chamber can be designed so that the flame, which arises during the combustion of fuel in the furnace, burns upright. The primary air supply may extend at least partially between the afterburner chamber and the bottom of the combustion chamber and / or the primary air supply may be partially, e.g. in the form of an air passage, extend through the afterburner chamber therethrough. As a result, supplied primary air can be preheated before it is guided into the combustion chamber. In addition, the primary air can be fed from below into the combustion chamber.

The flue gas can be sucked from an upper region of the combustion chamber through the flue gas channel, whereby the flame in the combustion chamber burns upright by the corresponding train, especially when primary air is supplied in a lower region and / or through the bottom of the combustion chamber.

Thus, the flame can, for example, be visible through a glass pane in the oven door.

In some embodiments, the combustion chamber can have an opening in an upper region of the rear wall through which flue gas flows from the combustion chamber into the flue gas channel. The flue gas channel can be connected directly to the opening or connected directly to it.

In some embodiments, the furnace may further comprise a housing, wherein the flue gas passage is partially formed by a rear wall of the housing. The flue gas duct may e.g. be formed between an outer side of the rear wall of the combustion chamber and an inner side of the rear wall of the housing. The side walls of the flue gas duct may e.g. be formed by the side end walls of the housing and / or the flue gas channel has corresponding side walls which extend away from the rear wall of the combustion chamber.

In some embodiments, the flue gas duct has a combustion air supply. The combustion air supply may also be connected to the primary air supply. By supplying fresh air into the flue gas duct, the afterburning of flue gas in the flue gas duct can be improved.

The afterburner chamber may also have a combustion air supply via which fresh air for the combustion of flue gas can be supplied. The combustion air supply may also be connected to the primary air supply.

In some embodiments, the afterburner has a flue gas port for connecting a heat exchanger. The heat exchanger can, for example, be water-conducting or have another storage material, such as, for example, firebricks or the like. In addition, the heat exchanger can also be configured as a convection air exchanger, in which the flue gas is heated by the emitted heat radiation (convection) air.

The flue gas connection can in principle be provided at any point in the afterburner chamber. In some embodiments, it is arranged on one or two sides and / or rear, so that in some embodiments, more than one heat exchanger can be supplied with flue gas and flowed through.

The flue gas, which flows through one or more heat exchangers, passes through a chimney connection into a chimney. In embodiments in which no heat exchanger is provided, the flue gas can also be passed directly through a chimney connection, which is provided, for example. Rear or top of the oven, in a fireplace.

As already stated, the furnace may comprise one (or more) heat exchangers which is connected to the flue gas connection of the afterburning chamber.

In addition, as indicated above, the furnace may comprise a housing, the afterburner chamber being partially formed by the housing. For example, the bottom of the afterburner may be formed by a bottom wall of the housing, the side walls by side end walls of the housing and / or the rear wall through the rear wall of the housing. The upper ceiling wall may, for example, be formed by a separate wall, which is arranged in the housing below the combustion chamber.

In some embodiments, the oven includes a grate and a primary air supply, wherein the primary air supply directs primary air from below through the grate into the combustion chamber. This type of primary air supply is known in principle and allows a good supply of the combustion chamber with primary air and allows good traction.

The oven may be configured as a natural draft oven and / or it may have a flue gas fan and / or a primary air fan.

Coming back to the FIGS. 1 to 2 These illustrate an embodiment of a furnace 1 according to the invention, which is designed, for example, for the combustion of wood.

The wood stove 1 has a combustion chamber 2 in which (symbolically) wood 4 is arranged as a solid fuel. An afterburner 3 for the combustion of the flue gas is arranged below the combustion chamber 2.

The combustion chamber 2 has a rear wall 7, at the top of which an opening 5 is provided, through which flue gas, which is formed during combustion of the wood 4 in the combustion chamber 2, enters a flue gas duct 6. The opening 5 is configured rectangular in the embodiment and has a cross section corresponding to the cross section of the flue gas channel 6.

The flue gas channel 6 connects the opening 5 with the afterburner chamber 3, flows from above into the afterburner chamber 3 and directs flue gas from the combustion chamber 2 into the afterburner chamber 3 (see arrows).

The wood-burning stove 1 has a housing 12 having a ceiling wall 12a, a rear wall 12b, a front wall 12c with an oven door 11, a bottom 12d, and two side walls 12e and 12f.

The combustion chamber 2 is formed by the front wall 12c, the ceiling wall 12, the rear wall 7, by two portions of the side walls 12e and 12f and a grid 10 on which the wood 4 is arranged for combustion.

The flue gas duct 6 is formed by the rear wall 7 of the combustion chamber 2, by a portion of the rear wall 12 b and portions of the side walls 12 e and 12 f and by a small portion of the ceiling wall 12 of the housing 12.

The flue gas channel 6 thus extends between the rear wall 7 of the combustion chamber 2 and the rear wall 12b of the housing 12, along the entire rear wall 7 of the combustion chamber 2 in the vertical direction until it opens into the afterburner chamber 3.

On the rear wall 12b of the housing 12, a combustion air connection 14 is provided approximately in the middle of the flue gas duct 6, can be passed through the fresh air into the flue gas duct 6 for combustion of flue gas in the flue gas duct 6.

The afterburner chamber 3 is formed by the bottom 12 d, two portions of the side walls 12 e and 12 f of the housing 12, by corresponding portions of the front wall 12 c and the rear wall 12 b of the housing 12 and a ceiling wall 16.

The ceiling wall 16 is spaced from the grid 10 and connected to the rear wall 7, and it separates the afterburner 3 and the combustion chamber 2 from each other such that the afterburner chamber 3 communicates with the combustion chamber 2 only via the flue gas channel 6.

Between the top wall 16 of the afterburning chamber 3 and the grate 10, a gap is provided in which a primary air supply 9 supplies primary air, so that primary air flows from below through openings of the grate 10 into the combustion chamber 2 and supplies the combustion there with primary air.

In the space between the top wall 16 of the afterburner 3 and the grid 10 may also be arranged an ash box (not shown).

The primary air supplied as described above supplies combustion of the wood 4 located on the grate 10 with oxygen from below. The resulting during combustion flue gas flows against the force of gravity in the combustion chamber 2 upwards and The flue gas duct 6 then directs the flue gas in the direction of gravity from above into the afterburner chamber 3 under the combustion chamber 2, wherein the flue gas burns in the flue gas duct 6 and in the afterburner chamber 3. Possibly. For example, a blower (not shown) may assist the flue gas flow.

On the rear wall 12b of the housing 12, a combustion air connection 15 is provided in the lower region of the afterburner chamber 3, is supplied through the fresh air for combustion of the flue gas in the afterburner 3.

The afterburner chamber 3 also has two flue gas ports 8a and 8b, which are arranged opposite each other in the left and right side wall 12e and 12f of the housing 12 in the region of the afterburner chamber 3.

At the flue gas port 8a of the right side wall 12e, a first heat exchanger 13a is connected, and at the opposite flue gas port 8b of the left side wall 12f is connected in the second heat exchanger 13b.

The two heat exchangers 13a and 13b are traversed by flue gas from the afterburning chamber 3 which, when flowing, transfers its heat to a heat storage medium, e.g. Water, in the heat exchanger 13 a and 13 b emits.

The heat exchangers 13a and 13b are connected via a chimney port to a chimney (not shown), so that the flue gas from the heat exchangers 13a and 13b is led into the chimney.

Claims (9)

Furnace for heat generation, in particular wood-burning stove, such as log burning stove or pellet stove, comprising: a combustion chamber (2) having a rear wall (7) and two side walls (12e, 12f); an afterburner chamber (3), which is arranged below the combustion chamber (2), and a flue gas duct (6) for supplying flue gas from the combustion chamber (2) into the afterburner chamber (3), the flue gas duct (6) being arranged on the rear wall (7) of the combustion chamber (2) or on one of the side walls (3a, 3b) is. Furnace for generating heat according to claim 1, wherein the combustion chamber (2) has an opening (5) in an upper region of the rear wall (7), flows through the flue gas from the combustion chamber (2) in the flue gas duct (6). A furnace for generating heat according to any one of the preceding claims, further comprising a housing (12), the flue gas duct (6) being formed in part by a rear wall (12b) of the housing (12b). Furnace for generating heat according to one of the preceding claims, wherein the flue gas duct (6) has a combustion air supply (14). A furnace for generating heat according to any one of the preceding claims, wherein the afterburner chamber (3) has a combustion air supply (15). Furnace for generating heat according to one of the preceding claims, wherein the afterburner chamber (3) has a flue gas connection (8a, 8b) for connecting a heat exchanger (13a, 13b) A heat generation furnace according to claim 6, further comprising a heat exchanger (13a, 13b) connected to the flue gas port (8a, 8b) of the afterburner chamber (3). A furnace for generating heat according to any one of the preceding claims, further comprising a housing (12), said afterburner chamber (3) being partially formed by said housing (12). Furnace for generating heat according to one of the preceding claims, further comprising a combustion grate (10) and a primary air supply (9), wherein the primary air supply (9) directs primary air from below through the combustion grate (10) in the combustion chamber (2).

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