EP3783263A1 - Pyrolysis furnace - Google Patents

Abstract

The present invention relates to a pyrolysis furnace, in particular a small pyrolysis furnace, which can be easily manufactured, maintained and repaired in poor rural regions using regionally available resources and labor. The pyrolysis furnace of the present invention is modular and has a guide for tertiary air which is fed to the combustion process, which improves the efficiency of the furnace.

Description

Field of invention

The present invention relates to a pyrolysis furnace, in particular a small pyrolysis furnace, for producing coal from a biogenic (fossil) fuel, which is used as a hotplate during the pyrolysis process.

State of the art

The most widely used hotplate worldwide is the firewood-powered 3-stone hob, in which the cooking vessel is heated on three stones over an open flame. When cooking with the 3-stone hob, toxic smoke gases are generated, which are a major health hazard for the user. There is also a high risk of burns from the open fire.

In addition, the efficiency of the 3-stone hob is low, which leads to high fuel consumption. This means that natural resources such as forest and bush areas are greatly reduced in the corresponding areas. This in turn leads to a reduction in fertile soils, as a result of which the nutritional situation of many people in the corresponding regions deteriorates.

Small pyrolysis ovens, also known as "gasifiers", are an efficient alternative to the conventional 3-stone hob. In addition to improved efficiency, they are characterized in particular by an almost smoke-free combustion, for example by means of a chimney system through which flue gases are removed, making them less have a harmful influence on the user. Pyrolysis ovens produce a wood gas from a fuel, for example wood, with the addition of primary air, which mixes with secondary air and burns almost smoke-free. During this so-called wood gasification phase, the fuel is turned into charcoal. There is also heat that can be used for cooking, for example. The charcoal can be removed and used again, for example as fuel or as an additive for the production of a natural fertilizer (natural fertilizer).

As a rule, small pyrolysis ovens are made of metal and / or ceramics and have separate guides for primary air and secondary air. The production of such However, small pyrolysis ovens are complex and require special knowledge and experience. As a result, such stoves cannot be manufactured or affordable for many households in developing countries.

The object of the present invention is to provide a pyrolysis furnace of reduced complexity, which can be easily manufactured, maintained and repaired at the village level with the locally available materials and labor. Furthermore, a pyrolysis furnace is provided, which makes it possible to directly and efficiently use the thermal energy that arises from wood gasification.

Brief description of the invention

The task is solved by the independent claim to protection. The dependent claims relate to further aspects of the invention.

In one aspect, the present invention relates to a pyrolysis furnace having a lower element, a middle element and an upper element. The lower element has at least one spacer which is configured to create a space between the lower element and the middle element. The middle element has an opening on its lower side and on its upper side. The middle element has a combustion chamber and a flame concentrator. The combustion chamber has a support for a fuel. Furthermore, the combustion chamber has a controllable inlet connection for primary air below the support. The combustion chamber is open on its upper side and has at least one inlet opening on an upper part of its side surface.

The combustion chamber is arranged essentially within the flame concentrator and the flame concentrator at least partially covers the top of the combustion chamber. On its top side, the flame concentrator has an opening whose cross section is smaller than the cross section of the top side of the combustion chamber. There is a gap between the outer side surface of the combustion chamber and the inner side surface of the flame concentrator, which gap is designed to lead secondary air to the inlet openings of the combustion chamber. Furthermore, there is a gap between the outer side surface of the flame concentrator and the inner side surface of the middle element, which gap is designed to guide tertiary air to the opening of the flame concentrator. The upper element has at least one opening. The combustion chamber is preferably supported by the lower element and / or the middle element.

The lower element and / or the middle element and / or the upper element is preferably made from a natural material, for example from a reinforced clay or concrete. The combustion chamber and / or the flame concentrator are preferably made of metal. Locally available metals, for example made from recycled sheet metal, are particularly preferred.

According to a further aspect of the present invention, the pyrolysis furnace preferably has an efficiency ring. The efficiency ring is preferably made of metal. The efficiency ring preferably has a size adjustment mechanism. Furthermore, the efficiency ring preferably has a viewing hole.

The pyrolysis oven preferably has at least one holder which is designed to support a cooking vessel. Furthermore, the side of the holder facing the cooking vessel is preferably inclined, so that different distances between the cooking vessel and the heat source can be set by changing its position in relation to the cooking vessel.

Brief description of the figures

Fig. 1:

Eine schematische Schnittansicht des Pyrolyseofens gemäß einem Aspekt der vorliegenden Erfindung;

Fig. 2:

Eine schematische Schnittansicht des Pyrolyseofens mit Effizienzring gemäß einem Aspekt der vorliegenden Erfindung; und

Fig. 3:

Eine schematische Schnittansicht des Pyrolyseofens mit Effizienzring und Haltern für ein Kochgefäß gemäß einem Aspekt der vorliegenden Erfindung.

The invention is explained in more detail with reference to the attached figures. Show it:

Fig. 1:

A schematic sectional view of the pyrolysis furnace according to an aspect of the present invention;

Fig. 2:

A schematic sectional view of the pyrolysis furnace with efficiency ring according to an aspect of the present invention; and

Fig. 3:

A schematic sectional view of the pyrolysis oven with efficiency ring and holders for a cooking vessel according to an aspect of the present invention.

Detailed description of the invention

Fig. 1 shows a pyrolysis furnace 1000 according to the invention. The preferably modular pyrolysis furnace 1000 has a housing 1, 2, 3, with at least one first air inlet for primary air 100 (solid line) and at least one second air inlet 11 for secondary air 200 (dashed line) and tertiary air 300 ( dotted line) in the lower area of the housing. The housing 1, 2, 3 also has a combustion gas outlet 8 its upper end. The housing 1, 2, 3 surrounds an upwardly open combustion chamber 4 with a controllable air inlet 7 which is in communication with the first air inlet of the housing and a flame concentrator 5 which surrounds the upper section of the combustion chamber 4. The air inlet 7 of the combustion chamber 4 is preferably formed by an inlet connector. The inlet connector preferably extends radially, ie perpendicular to the longitudinal axis of the combustion chamber 4, so that the opening of the inlet connector penetrates at least one side wall of the housing 1, 2, 3 or protrudes beyond it.

The flame concentrator 5 comprises an opening 51 on its upper side, the cross section of which is smaller than the cross section of the upper opening of the combustion chamber 4. A gap 24 is formed between the outer wall of the combustion chamber 4 and the inner wall of the flame concentrator 5, through which the secondary air 200 is guided to inlet openings 41 which are provided in the upper section of the combustion chamber 4. Between the outer wall of the flame concentrator 5 and the inner wall of the housing 1, 2, 3 there is a gap 25 through which tertiary air 300 is passed into the area of the upper opening 51 of the flame concentrator 5.

The housing 1, 2, 3 and / or the combustion chamber 4 and / or the flame concentrator 5 preferably have a cylindrical shape. The housing 1, 2, 3 is particularly preferably arranged coaxially with the combustion chamber 4 and / or the flame concentrator 5. The cross section of the housing 1, 2, 3 and / or the combustion chamber 4 and / or the flame concentrator 5 is preferably circular, elliptical, rectangular or square.

The housing 1, 2, 3 is preferably made of a natural material, for example clay or concrete. The housing is particularly preferably made from a reinforced clay or concrete.

According to a further aspect of the present invention, the pyrolysis furnace 1000 preferably has an efficiency ring 9 on the housing section 3 (see FIG Fig. 2 ) on. The efficiency ring 9 is preferably made from a locally available material, for example from recycled sheet metal. The efficiency ring 9 preferably has a mechanism for size adjustment, by means of which its circumference can be adapted to the circumference of a cooking vessel. The cooking vessel (not shown) can be positioned on an upper side of the housing 1, 2, 3. Furthermore, the efficiency ring 9 preferably has an opening 91 through which the user can Can observe the combustion process without having to open the pyrolysis furnace 1000 for this purpose.

The pyrolysis furnace 1000 preferably has at least one holder 10 on the housing section 3 (see FIG Fig. 3 ), which is designed to place the cooking vessel thereon and to create a distance between the top of the housing 1, 2, 3 and the cooking vessel. Furthermore, the side of the holder 10 facing the cooking vessel is preferably inclined, so that different distances between the cooking vessel and the combustion gas outlet 8 of the housing 1, 2, 3 can be set by changing its position. Particularly preferably, the holder 10 can consist of several parts that are movable relative to one another.

The housing 1, 2, 3 is preferably of modular design, with a lower element 1, a middle element 2 and an upper element 3. The lower element 1 preferably has at least one spacer 15, which is designed to be between the lower element 1 and to create a distance to the middle element 2, so that a second air inlet 11 is formed. Secondary air 200 and tertiary air 300 flow through this air inlet 11 into the interior of the middle element 2. The upper element 3 has the combustion gas outlet 8.

The middle element 2 has at least one opening each on its underside and on its upper side. The middle element 2 is preferably cylindrical or conical. The middle element 2 encloses the combustion chamber 4 and the flame concentrator 5.

The combustion chamber 4 preferably has a support 6 for fuel. The combustion chamber 4 has an air inlet 7 for primary air 100 below the support 6. The air inlet 7 extends preferably perpendicular to the longitudinal axis of the combustion chamber 4 in a radial direction, with at least the opening of the air inlet 7 penetrating the outer wall of the housing 1, 2, 3. The air inlet 7 particularly preferably extends radially into the distance formed by the spacer 15 between the lower element 1 and the middle element 2.

In an upper region, the combustion chamber 4 has at least one inlet opening 41 through which secondary air 200, which flows into the middle element 2 through the air inlet 11, is guided into the combustion chamber 4.

The combustion chamber 4 is surrounded in an upper region by the flame concentrator 5, and the flame concentrator 5 covers the upper side of the combustion chamber 4 at least partially. The flame concentrator 5 has an opening 51 on its upper side. The opening 51 of the flame concentrator 5 has a smaller cross section than the cross section of the open top of the combustion chamber 4.

The combustion chamber 4 is preferably supported by the lower element 1 and / or the middle element 2. The lower element 1 and / or the middle element 2 and / or the upper element 3 are preferably made of a natural material, for example clay or concrete. The natural material is particularly preferably reinforced. The combustion chamber 4 and / or the flame concentrator 5 are preferably made of a locally available material. The combustion chamber 4 and the flame concentrator are particularly preferably made from locally available metal, for example from recycled sheet metal.

A gap 24 is formed between the outer wall of the combustion chamber 4 and the inner wall of the flame concentrator 5, through which secondary air 200, which flows through the air inlet 11 into the middle element 2, is guided to inlet openings 41 which are provided in the upper section of the combustion chamber 4 . Between the outer wall of the flame concentrator 5 and the inner wall of the middle element 2 of the housing 1, 2, 3 there is a gap 25 through which tertiary air 300 is passed into the region of an upper opening 51 of the flame concentrator 5.

The combustion process of the fuel, which is preferably located on the support 6 of the combustion chamber 4, takes place via the supply of primary air 100 into the combustion chamber 4 through the adjustable air inlet 7. The fire is started in the upper area of the combustion chamber and the wood gas production then continues up to in the lower area of the combustion chamber (top to down concept) to support the fuel chamber and produces the charcoal in this combustion phase. After lighting, the cross section of the air inlet 7 is reduced (closed) by a metal slide after a certain time in order to avoid the fuel being completely burned by too much (continuous supply of) primary air 100. By reducing (closing) the air inlet 7, the fuel is more effectively charred.

In the course of the carbonization of the fuel, combustion gas is produced, which rises into the upper part of the combustion chamber 4. Due to the smaller cross section of the upper opening 51 of the flame concentrator 5 relative to the cross section of the open top of the combustion chamber 4, the combustion gas does not leave the combustion chamber 4 unimpeded, but is bundled at the upper end of the combustion chamber 4. Secondary air 200 is admixed with the hot combustion gas through the inlet openings 41 in the upper region of the combustion chamber 4, and the combustion gas also burns.

The combustion gas continues to rise through the upper opening 51 of the flame concentrator 5 in the direction of the combustion gas outlet 8 of the housing 1, 2, 3. After the combustion gas has passed the upper opening 51 of the flame concentrator 5, it mixes in the gap 25 with the tertiary air 300 passing through the air inlet 11 is passed into the housing 1, 2, 3 to the upper opening 51 of the flame concentrator 5. As a result of the supply of tertiary air 300, further, previously unburned portions of the combustion gas flowing out of the combustion chamber 4 and the flame concentrator 5 burn.

The heat generated during the combustion and charring as well as unburned components of the combustion gas exit the housing 1, 2, 3 through the combustion gas outlet 8. According to one aspect of the invention, the resulting heat is used to heat a cooking vessel which is located above the combustion gas outlet 8.

With the pyrolysis furnace according to the present invention, secondary air 200 and later tertiary air 300 is supplied to the combustion of the wood gas. This creates an afterburning effect, which improves the thermal efficiency of the pyrolysis furnace and reduces smoke formation.

Thanks to the size-adjustable efficiency ring, the energy used for cooking is directed specifically to the cooking vessel, which is also beneficial for the thermal efficiency of the pyrolysis oven.

Due to the improved efficiency, the fuel consumption can be reduced compared to conventional pyrolysis ovens or the 3-stone hob. This has a positive effect on the environment and reduces operating costs.

Furthermore, with the pyrolysis furnace according to the invention, no fire management is necessary after lighting, which simplifies handling and reduces the risk of burns.

The production costs of the pyrolysis furnace according to the invention are many times lower compared with conventional small pyrolysis ovens, since cheap, locally occurring materials are used, such as clay, concrete or recycled metal. Thus, the pyrolysis furnace of the present invention can be produced regionally, whereby jobs are created on a regional / village level.

Due to its modular design, the pyrolysis furnace can be repaired easily and inexpensively and enables simple, inexpensive maintenance on site. This creates closed economic cycles in poor, rural regions, which is also beneficial for the residents there.

Although the invention is illustrated and described in detail by means of the figures and the associated description, this illustration and this detailed description are to be understood as illustrative and exemplary and not as limiting the invention. It is understood that those skilled in the art can make changes and modifications without departing from the scope of the following claims. In particular, the invention also comprises embodiments with any combination of features that are mentioned or shown above in relation to various aspects and / or embodiments.

The invention also includes individual features in the figures even if they are shown there in connection with other features and / or are not mentioned above.

In the following, the term “comprise” and derivatives thereof do not exclude other elements or steps. Likewise, the indefinite article “a” or “an” and derivatives thereof do not exclude a plurality. The functions of several features listed in the claims can be fulfilled by one unit. The terms “essentially”, “about”, “approximately” and the like in connection with a property or a value also define, in particular, precisely the property or precisely the value. All reference signs in the claims are not to be understood as limiting the scope of the claims.

Claims (13)

Pyrolysis oven (1000) with: (a) a housing (1, 2, 3) (Al) with at least one first air inlet for primary air (100) and at least one second air inlet (11) for secondary air (200) and tertiary air (300) in the lower region of the housing and (a2) a combustion gas outlet (8) at the upper end of the housing, (b) a combustion chamber (4) which is open at the top and is arranged in the housing (1, 2, 3) and has an air inlet (7) which is arranged in the lower region of the combustion chamber (4) and communicates with the first air inlet of the housing, and (c) a flame concentrator (5) which surrounds an upper section of the combustion chamber (4) and which has an upper opening (51) which is smaller in cross section than the cross section of the upper opening of the combustion chamber (4), (d) a gap (24) for introducing the secondary air (200) to inlet openings (41) in the upper section of the combustion chamber (4) being provided between the outer wall of the combustion chamber (4) and the inner wall of the flame concentrator (5), and (e) wherein between the outer wall of the flame concentrator (5) and the inner wall of the housing (1, 2, 3) a gap (25) for introducing the tertiary air (300) into the area of the upper opening (51) of the flame concentrator (5) is provided. Pyrolysis furnace (1000) according to claim 1, wherein the housing (1, 2, 3) and / or the combustion chamber (4) and / or the flame concentrator (5) are cylindrical. Pyrolysis furnace (1000) according to Claim 2, the housing (1, 2, 3) being arranged coaxially with the combustion chamber (4) and / or the flame concentrator (5). Pyrolysis furnace (1000) according to one of Claims 1 to 3, the housing (1, 2, 3) being made from a natural material. Pyrolysis furnace (1000) according to one of Claims 1 to 4, the housing (1, 2, 3) being of modular design with a lower element (1), a middle element (2) and an upper element (3). Pyrolysis furnace (1000) according to claim 5, wherein the combustion chamber (4) is supported by the lower element (1) and / or the middle element (2). Pyrolysis furnace (1000) according to one of Claims 1 to 6, the combustion chamber (4) and / or the flame concentrator (5) being made of metal. Pyrolysis furnace (1000) according to one of Claims 1 to 7, which has an efficiency ring (9). Pyrolysis furnace (1000) according to claim 8, wherein the efficiency ring (9) has a mechanism for size adjustment. Pyrolysis furnace (1000) according to Claim 8 or 9, the efficiency ring (9) having an opening (91) on a side wall. The pyrolysis oven (1000) according to any one of claims 1 to 10, which has at least one holder (10) for supporting a cooking vessel. Pyrolysis oven (1000) according to claim 11, wherein a side of the holder (10) facing the cooking vessel is inclined. Pyrolysis furnace (1000) according to one of Claims 11 or 12, the holder (10) consisting of several parts which can move relative to one another.

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