EP3841327A1

EP3841327A1 - Method for operating a combustion facility and combustion facility

Info

Publication number: EP3841327A1
Application number: EP19762725.0A
Authority: EP
Inventors: Wolfgang Kirschbaum
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-08-20
Filing date: 2019-08-20
Publication date: 2021-06-30
Also published as: JP2021536562A; WO2020038926A1; US20210172601A1; KR20210045440A; CN112585405A; CA3110130A1; DE102018120196B3

Abstract

The invention relates to a method for operating a combustion facility (1), said combustion facility (1) comprising a combustion chamber (3) arranged in a double-walled housing (2), a supply duct (4) for supplying a fuel into the combustion chamber (3), a discharge duct (5) for removing exhaust air from the combustion chamber (3), and an air channel (6) for supplying supply air into the housing (2), wherein the housing (2) comprises an inner wall (7) and an outer wall (8) which define an intermediate space (9) therebetween, wherein an air inlet (10) that cooperates with the air channel (6) is arranged in an upper end section (14) of the outer wall (8), and the intermediate space (9) and the combustion chamber (3) that is surrounded by the inner wall (7) are fluidically interconnected, said method comprising the following steps: a) supply air is introduced into the upper end section (14) of the housing (2) by means of the air channel (6); b) the supply air is guided in the intermediate space (9) towards a lower end section (15) of the housing (2); and c) the supply air is introduced into the combustion chamber (3). The aim of the invention is provide a combustion facility by means of which renewable raw materials with low energy content can be used. To this end, the method according to the invention includes the following step: the supply air is first guided out of the housing (2) by means of an air duct (11) that cooperates with an air outlet (12) arranged in the outer wall (8) and is then at least indirectly supplied to the combustion chamber (3).

Description

Method for operating a burning device and burning device

description

introduction

The present application relates to a method for operating a burning device according to the preamble of claim 1. Furthermore, the present application relates to a burning device according to the preamble of claim 8.

Such a combustion device comprises a double-walled housing, which comprises an inner wall and an outer wall surrounding the inner wall. The housing can in particular be designed with a circular cross section. The configuration with an angular, in particular rectangular or square, cross section is also conceivable. There is an intermediate space between the inner wall and the outer wall. A combustion chamber is arranged inside the interior, in which a fossil or renewable fuel can be burned. In particular, it is conceivable to burn pellets formed from renewable raw materials. In order to be able to operate the combustion, supply air must be supplied to the combustion chamber. The combustion device therefore comprises at least one air duct, by means of whose supply air can be conducted into the housing. Furthermore, the combustion device comprises at least one discharge line which is suitable for discharging exhaust air from the combustion chamber. In particular, these can be exhaust gases that are produced in the course of the combustion of a particular fuel. For the purpose of supplying fuel to the combustion chamber, the combustion device also has a corresponding supply line,

The air duct, by means of which the supply air can be conducted into the housing, is connected to the housing in an upper end section of the outer wall of the housing.

Accordingly, the combustion device has an air inlet opening in the upper end section of the outer wall, which cooperates with the air duct. In this way, supply air is in the air located between the inner wall and the outer wall

Gap can be introduced. The intermediate space and the combustion chamber are also connected to one another in terms of flow technology, so that the supply air introduced into the intermediate space can be transferred into the combustion chamber. This takes place in particular in a lower end section of the housing, the supply air starting from that in the upper one

End portion arranged air inlet opening is guided in the direction of the lower end portion of the housing before it is at least indirectly introduced into the combustion chamber. State of the art

[04] Burning devices of the type described above are already known in the prior art. For this purpose, reference is made, for example, to European Patent Application EP 2 458 275 A1. This describes a kiln for the combustion of

renewable raw materials such as wood or wood chips. The furnace has a double-walled housing, by means of which a combustion chamber is enclosed. On an upper side of an outer wall of the housing, the furnace has a fan, by means of which supply air can be introduced into an intermediate space located between the outer wall and an inner wall of the housing. Within the intermediate space, the supply air is first routed in a spiral around the combustion chamber, that is to say around the inner wall, and heated in the process, the inner wall being cooled at the same time. The preheated supply air is finally introduced into the combustion chamber through transfer openings and is then available for the combustion reaction.

[05] Further burners are, for example, from the documents

US 2007/0272201 A1 and EP 2 236 940 A1 are known.

[06] Combustion devices of the known type are generally not suitable for burning highly compressed fuels. These can be pressed pellets, for example, which are produced from waste materials, in particular those from agriculture. For example, it is conceivable to dry agricultural manure and press it into such pellets. However, such pellets burn much worse than, for example, wood pellets. It has been found that the known

Burners with such a fuel do not work satisfactorily.

task

[07] The object of the present application is therefore to provide a method and a combustion device by means of which even highly compressed fuels can be burned.

solution

[08] The underlying object is achieved according to the invention by a method with the features of claim 1. Advantageous refinements result from subclaims 2 to 7.

The method according to the invention is characterized in that the supply air after it has been introduced into the intermediate space and before it is introduced into the combustion chamber by means of an air line out of the housing and then at least indirectly the

Combustion chamber is fed. For this purpose, the air line interacts with an air outlet opening arranged in the outer wall, through which the supply air can be guided out of the intermediate space and thus out of the housing. In particular, the supply air can be transferred by means of the air line to a separate area of the intermediate space, which is spatially separated from the area of the intermediate space to which the supply air is supplied by means of the air duct. For example, the intermediate space can be divided into two separate areas by means of an intermediate floor. By means of the air line, the supply air can then be supplied from the first area to the second separated area of the intermediate space. Starting from this separated area, the supply air is then fed to the combustion chamber, so that the supply air as a whole is fed indirectly to the combustion chamber by means of the air line. In the case of a direct supply line, the air line is connected directly to the inner wall, the air line in particular being able to penetrate the intermediate space. In this embodiment, the supply air can flow directly into the combustion chamber from the air line through a transfer opening.

[10] The method according to the invention has many advantages. In particular, by guiding the supply air before it is led into the combustion chamber by means of the air line, the possibility is created of interrupting a flow of the air line that is in the intermediate space, which in particular extends spirally around the inner wall, and then of the supply air specifically with a different flow characteristic the

To feed the combustion chamber. The supply of the (preheated) supply air to the combustion chamber can hereby be set precisely, whereby the combustion reaction taking place in the combustion chamber can be influenced in a targeted manner. In particular, it is possible to supply the supply air in a circular manner in the course of its supply to the combustion chamber according to the principle of a swirl chamber, first around the burner plate on which the respective fuel is burned and then in the radial direction of the flame. This type of air flow has ultimately proven to be particularly positive in connection with the combustion of highly compressed fuels.

[11] As already indicated above, it can be particularly advantageous if the space is divided into an upper area and an area by means of an intermediate floor

Sub-area is divided. The intermediate base is preferably oriented horizontally and arranged in the lower end section of the housing. The air line is arranged on the housing in such a way that the supply air, which is introduced into the intermediate space in the upper end section and therefore in the upper region of the housing, exclusively by means of the Air line is led from the upper area to the lower area of the intermediate space. The interruption of the intermediate space by means of the intermediate base means that a flow of the supply air prevailing in the upper region, which is in particular formed spirally around the inner wall, cannot be transferred to the flow prevailing in the lower region of the intermediate space. Instead, the

Flow characteristics of the supply air in the upper area of the intermediate space with the introduction of the supply air into the air line and the associated line of the supply air “broken off” from there, whereupon the supply air in the course of the supply line to the

A “new” flow characteristic can be impressed on the lower part of the gap,

[2] Advantageously, the supply air is then fed to the combustion chamber through at least one transition opening after it has been fed to the lower region of the intermediate space. The lower region of the intermediate space and the combustion chamber are preferably connected to one another in terms of flow technology by means of a plurality of transition openings. For example, it is conceivable that the inner wall has a total of four transition openings which are arranged in the inner wall in a uniformly distributed manner in a horizontal plane (that is to say each offset by 90 °). Transfer openings are advantageously designed with such a small cross section, in particular in the form of horizontal slots, that the transfer openings act as throttles, so that the

Overflow of the supply air from the sub-area of the intermediate space into the combustion chamber takes place at least substantially uniformly through all the transfer openings. Furthermore, the throttling effect leads to a local acceleration of the flow of the supply air. The higher flow velocity of the supply air contributes to more turbulent combustion in the combustion chamber, which can then develop higher temperatures and cause a highly compressed fuel to break open.

[13] The supply air is advantageously deflected in the course of the passage into the combustion chamber by means of at least one air guiding element. This deflection advantageously takes place in such a way that a tangential flow component is impressed on the supply air. This means that when the air enters the combustion chamber, it is not fed directly in a radial direction to the burner plate and therefore to the fire, but rather initially "swirls" the burner plate in a circle, which has proven to be particularly advantageous with regard to the combustion reactions. The radial supply of air in the direction of the burner plate or the fire on it is driven by the negative pressure or “suction” that occurs in the area of the burner plate due to the oxygen consumption of the burning reaction. As already indicated above, it is fundamentally particularly advantageous if the supply air spirally turns in the course of its flow starting from the air inlet opening arranged in the upper end section of the housing in the direction of the air outlet opening of the outer wall arranged in the lower end section of the housing the inner wall is led around. This air flow is accompanied by a much greater heating of the supply air along the inner wall than if the supply air were only guided linearly downwards along the inner wall. The spiral guide leads to the fact that an air duct, over which the supply air along the

Inner wall of the burner flows, is comparatively long. Accordingly, the dwell time of the supply air on the inner wall is also comparatively long, which means that the supply air can be heated particularly strongly. In other words, there can be a large amount of thermal energy transition from the inner wall to the supply air. The high temperature of the supply air when it is introduced into the combustion chamber is of particular importance in order to also burn fuels with a high compression.

[15] The spiral flow of the supply air around the inner wall can

be forced in particular by means of air guiding elements. In this case, the supply air is advantageously deflected within the intermediate space by means of at least one air guiding element. In particular, it is advantageous if the supply air is passed from the air duct through the air inlet opening into the intermediate space immediately after it has passed, by means of which the supply air can be impressed with the spiral flow.

[16] As an alternative or in addition to the deflection of the supply air by means of at least one air guide element, it can be advantageous to consider the supply air - viewed in a horizontal sectional plane of the combustion device - with a tangential directional component in the

To initiate space. The air duct is preferably at least in a connection area with which it connects directly to the outer wall of the housing

is connected, aligned obliquely with respect to the outer wall in such a way that a main flow direction of the supply air with the outer wall in the region of the

Air inlet opening includes an angle in the range between 60 ° and 90 °, preferably between 70 ° and 90 °, more preferably between 80 ° and 90 °. In this way, the supply air is already supplied to the intermediate space with a tangential flow component, as a result of which the spiral flow can be set.

[17] In terms of device technology, the underlying task

solved according to the invention by means of a burner with the features of claim 8. Advantageous refinements result from subclaims 9 to 16. [18] The combustion device according to the invention is characterized by an air line which cooperates with its first end with an air outlet opening which is arranged in a lower end section of the housing. Starting from this air outlet opening, the air line initially extends out of the housing or in one direction away from the housing, so that at least one outer section of the air line extends outside the housing. Finally, the air line is designed such that the supply air can be supplied at least indirectly to the combustion chamber by means of the air line. Such an indirect supply line can consist, for example, of first supplying the supply air to the intermediate space again, in particular a separated area of the intermediate space, before finally supplying the supply air through at least one transfer opening

Inner wall is transferred into the combustion chamber. In particular, the air line can interact with a passage cross section arranged in the outer wall.

Alternatively, a direct supply of the supply air into the combustion chamber can consist in the fact that the air line is connected directly to the inner wall starting from the outlet opening, so that the supply air through one of the air outlet openings

opposite second end of the air line arranged transition opening can be introduced into the combustion chamber. In this variant, the air line is preferably guided in the radial direction through an opening in the outer wall and through the intermediate space.

[19] The process according to the invention can be carried out using the process according to the invention

Carry out the burner particularly easily. The advantages already set out above are achieved here. In particular, the possibility is created to specifically impart a flow characteristic to the supply air after it has warmed up, which the supply air experiences in the course of its flow in the intermediate space along the inner wall, which is advantageous for combustion even of highly compressed fuels.

[20] In an advantageous embodiment of the combustion device according to the invention, it comprises an intermediate floor, by means of which the intermediate space is divided into an upper region and a lower region. The intermediate floor is advantageously arranged in a lower end section of the housing, the intermediate floor preferably being arranged directly below the air outlet opening. The air line leads from the air outlet opening - and thus the upper area of the intermediate space - into the lower area of the intermediate space located below. In this way, a flow characteristic impressed in the sub-area of the supply air can be set completely independently of the flow characteristic in the ear area of the intermediate space. The air line is preferably to a passage opening arranged in the outer wall connected so that the air line is connected to the outer wall with both ends. In particular, the air line can be designed in the form of a 180 ° bend which is oriented vertically, that is to say whose two ends are arranged one above the other.

Advantageously, the inner wall has at least one, preferably a plurality of transition openings, by means of which a fluidic connection is made between the intermediate space and the combustion chamber. The transition openings are preferably arranged in a lower region of the intermediate space, which is structurally separated, in particular by means of an intermediate floor, from an upper region of the intermediate space. If there are a plurality of transition openings, it is furthermore advantageous if they are designed to be evenly distributed on the inner wall.

[22] The outer wall advantageously has a passage opening which interacts with the air line. In particular, the passage opening can interact fluidically with a second end of the air line, so that the air, starting from the air outlet opening, which corresponds to the first end of the air line, can be directed to the second end and hence the passage opening, through which the supply air can be passed back to the intermediate space , The passage opening can in particular be arranged in a sub-area of the intermediate space described above. In this way, the supply air can be directed solely from the upper region of the intermediate space to the lower region of the intermediate space by means of the air duct. One in the

The prevailing flow characteristic of the supply air is destroyed in the course of the flow of the supply air through the air duct, whereupon a “new” flow characteristic can be impressed on the supply air in the lower region.

[23] The combustion device according to the invention, the air duct is connected to the outer wall of the housing such that a central axis of the air duct in the region of the air inlet opening forms an angle with the outer wall in the range between 60 ° and 90 °, preferably between 70 ° and 90 ° more preferably between 80 ° and 90 °. In this way it is possible for the air duct

Intermediate supply air already tangential in the course of the supply line

Imprint flow directions, which is then particularly easy to convert into a spiral flow characteristic within the space. In this way, it is possible in a particularly simple manner to conduct the supply air spirally from the air inlet opening along the inner wall in the direction of the lower end section of the housing and thus in the direction of the air outlet opening. The advantages resulting from this have already been set out above. [24] Regardless of the orientation of the air duct relative to the housing, it can also be particularly advantageous if the combustion device has a plurality of air guiding elements which are arranged in the intermediate space. Advantageously, one of the air guide elements, preferably all the air guide elements, are arranged on the inner wall of the housing, these air guide elements starting from the

Extend inner wall in the direction of the outer wall and thus within the space. By means of the air guiding elements, it is possible in a particularly simple manner to impart the desired spiral flow characteristic to the supply air within the intermediate space, which leads to particularly strong heating of the supply air on the inner wall of the housing. The air guide elements can be formed in particular by plate-shaped guide plates. Such baffles allow by means of a corresponding inclination and advantageous

Dimensions a targeted influence on the flow characteristics of the supply air.

Furthermore, such a combustion device can be of particular advantage, the space between which is divided into a wide area and a narrow area. In the wide area, a horizontally measured width of the space exceeds the width of the space measured in the narrow area. In a typically circular

Cross-sectional housing is advantageously a diameter of the outer wall constant over the height of the housing, while a diameter of the inner wall is different across the height of the housing. In particular, it can be advantageous if the diameter of the inner wall is in an upper one

End portion of the housing is smaller than in a lower end portion of the housing. Advantageously, the diameter of the inner wall increases suddenly from a small diameter to a large diameter. The wide area of the space describes the area in which the inner wall has the small diameter, while the narrow area describes the area of the space in which the

Inner wall has the large diameter.

The wide area of the intermediate space advantageously corresponds to the air inlet opening of the air duct. This offers the particular advantage that in the

Sufficient space is available to redirect the supply air introduced into the intermediate space by means of comparatively large air guide elements, so that the supply air subsequently has a desired, in particular spiral, flow characteristic. As soon as the supply air has the desired flow characteristics, the larger space which the intermediate space has in its wide area is then no longer required to control the flow of the supply air in the desired manner. Instead, the large diameter of the inner wall offers a larger circumferential surface Inner wall, which is available as a heat exchanger surface for the supply air. The efficient heating of the supply air in the narrow area of the intermediate space is therefore particularly easy. The air outlet opening, through which the supply air is guided out of the housing according to the invention by means of the air line, is advantageously arranged in the narrow region of the intermediate space.

Irrespective of the smaller available space, air supply of the supply air is also possible in the narrow area, wherein in particular elongated air guiding elements running in the circumferential direction of the inner wall or slightly inclined against the circumferential direction can be arranged on the inner wall. These can help to maintain the desired spiral flow of the supply air in the narrow area and to control the spiral flow of the supply air with a comparatively small slope. The air duct along which the supply air flows through the space between the air inlet opening and the air outlet opening is then particularly long, as a result of which the desired heat transfer from the inner wall to the supply air is made possible to a considerable extent.

embodiments

[28] The invention is explained in more detail below on the basis of exemplary embodiments which are illustrated in the figures. It shows:

Fig. 1: A vertical cross section through an inventive

Burning device,

Fig. 2: A horizontal cross section through a sub-area of the

1 according to FIG.

Fig. 3: A vertical cross section through a further invention

Burner and

4: A horizontal cross section through the combustion device according to FIG. 3.

A first exemplary embodiment, which is shown in FIGS. 1 and 2, comprises a combustion device 1 according to the invention, which has a combustion chamber 3 surrounded by a housing 2 with a circular cross section. The combustion device 1 has a feed line 4 by means of which a fuel, in particular in the form of pellets, can be fed to a burner plate 27 within the combustion chamber 3. The feed line 4 is guided through the housing 2 here. The housing 2 is double-walled and therefore comprises one

outer wall 8 and an inner wall 7 Die

The outer wall 8 and the inner wall 7 together delimit one in between io

Interstice 9 located. Furthermore, the combustion device 1 according to the invention has a discharge line 5, which is arranged on a ceiling 36 of the housing 2. The discharge line 5 is used to discharge exhaust gases, in particular flue gases, which occur in the combustion chamber 3 as a result of the combustion of the respective fuel.

Typically, such a combustion device 1 also has at least one heat exchanger arrangement, not shown in the figures, by means of which the thermal energy released in the course of the combustion reaction can be transferred to a heat transfer medium. The latter is typically formed by water, it being possible for the heat exchanger arrangement to be formed, for example, in the form of a water coil which extends spirally within the combustion chamber 3 and around which hot exhaust gases from the combustion reaction taking place in the combustion chamber 3 flow. In such a water snake, thermal energy contained in the exhaust gases can be transferred to the heat transfer medium and the latter can thereby be heated up considerably. In particular, the heat transfer medium is first evaporated and then preferably the steam is then overheated, for example to a temperature in the range above 500 ° C. In this way, the energy contained in the respective fuel is first converted into thermal energy and then made mechanically usable, it being possible, for example, to drive a turbine by means of the steam generated, typically by means of water vapor generated. The exhaust gas leaving the combustion device 1 can furthermore be replaced for the pre-drying of a fuel to be burned.

[31] An air duct 6 is connected to the intermediate space 9, with supply air being able to be introduced into the intermediate space 9 by means of the air duct 6 through an air inlet opening 10. The air inlet opening 10 is arranged in an upper end section 14 of the housing 2, the air inlet opening 10 advantageously being arranged directly below a ceiling 36 of the housing 2. The supply air initially flows in the air duct 6 along a main flow direction 16 parallel to a central axis 24 of the air duct 6, before it is deflected in the intermediate space 9 by means of air guide elements 26, 31. These air guide elements 26, 31 are arranged in the intermediate space 9 and serve to force the supply air into a spiral flow around the inner wall 7. This is based on the consideration that the supply air can be heated by flowing around the inner wall 7, the inner wall 7 taking place in the combustion chamber 3 as a result of this

Combustion has a high temperature. In this way, the supply air is guided downward from the air inlet opening 10 within the intermediate space 9 in the direction of a lower end section 15 of the housing 2 and is heated in the process. The air guiding elements 26, 31 are designed differently in the example shown. In particular, the air guide elements 26 are assigned to an upper wide area 34 of the housing 2, while the air guide elements 31 are assigned to a narrow area 33. The wide area 34 and the narrow area 33 differ in the width or extent of the intermediate space 9 measured in the radial direction. In the example shown, the housing 2 is constructed such that a diameter of the outer wall 8 is constant over the entire height of the housing 2 , The inner wall 7, on the other hand, is designed with a variable diameter, the inner wall 7 having a small diameter in the wide area 34 and a large diameter in the narrow area 33. As a result, a radially measured distance between the

Inner wall 7 and outer wall 8, which corresponds to the width of the intermediate space 9, is larger in the wide area 34 than in the narrow area 33. The wide area 34 is typically assigned to the upper end section 14, in which the air inlet opening 10 of the air duct 6 is arranged. The wide area 34 offers the advantage that in the

Space 9 has enough space to be comparatively large

To provide air guiding elements 26. These serve to initially impart a spiral flow to the supply air, the air guide elements 26 being arranged in a corresponding orientation on the inner wall 7. The air guide elements 26 are from here

plate-shaped components are formed, which extend from the inner wall 7 in the direction of the outer wall 8. The air guiding elements 26 can be at least partially inclined to a vertical to deflect the

Main flow direction 16 of the supply air to produce "obliquely downwards".

[33] As soon as the spiral flow of the supply air is set, further measures to maintain this spiral flow are only necessary by means of smaller air guide elements 31. These are arranged in the narrow area 33 and are in the example shown elongated, the curvature of the inner wall 7 adapted

Air baffles formed. These can differ in particular in the circumferential direction

Inner wall 7 viewed at least substantially extend horizontally or be slightly inclined to the horizontal, in particular by less than 10 °, preferably by less than 5 °. A part of the air guide elements 31 is preferably arranged horizontally, while another part of the air guide elements 31 is designed to be inclined to the horizontal. In this way, air channels are formed along the inner wall 7 in the narrow area 33 to a certain extent, which receive a spiral flow of the supply air around the inner wall 7, with an increase in the flow being kept so small that an air duct and consequently also a dwell time of the supply air the inner wall 7 are as long as possible in the course of the flow through the intermediate space 9. This ensures that a pronounced heat transfer from the

Inner wall on the supply air can take place, whereby the supply air is heated particularly strongly. The latter is for the combustion of highly compressed fuels in the

Combustion chamber 3 is particularly advantageous. The large diameter of the inner wall 7 in the narrow area 33 means that the circumferential surface of the inner wall 7 is particularly large, as a result of which the air guide path along which the supply air flows around the inner wall 7 is particularly long.

In the lower end section 15, which is located below the upper end section 14, the outer wall 8 has an air outlet opening 12 which interacts with an air line 11. The air outlet opening 12 is arranged here in the narrow area 33. By means of this air line 11, the supply air can be led from the intermediate space 9 in a direction radially outward from the housing 2. In other words, the air line 11 extends to a certain extent in an environment 23 of the housing 2. The air line 11 is at its first end 18 connected to the air outlet opening 12. A second end 19 of the air line 11 interacts with a passage opening 22, which is likewise arranged in the outer wall 8 of the housing 2. The air line 11 is accordingly designed to a certain extent in the form of a 180 ° bend which is oriented vertically, the two ends 18, 19 of which are arranged at different height levels. Extending between the air outlet opening 12 and the passage opening 22 is an outer section 21 of the air line 11, which in the example shown forms the complete air line 11.

[35] In the example shown, the intermediate space 9 is divided into an upper region 29 and a lower region 30 with an intermediate floor 28. The intermediate floor 28 is suitable for fluidically separating the upper region 29 and the lower region 30 of the intermediate space 9. A flow of the supply air from the upper region 29 into the lower region 30 is therefore only possible by means of the air line 11. The air outlet opening 12 cooperates with the upper region 29 and the through opening 22 with the lower region 30 of the intermediate space 9. Correspondingly, the air line 11 is the only fluidic connection between the upper region 29 and the lower region 30

Sub-area 30 of the space 9 fed. Starting from the sub-area 30, the supply air is then transferred into the combustion chamber 3 by means of a plurality of through openings 13 which are arranged in the inner wall 7. Within the

Combustion chamber 3, the supply air is finally fed to the fire 25, so that supply air is available as a reaction partner for the combustion reaction of the respective fuel. [36] As can be seen in particular from FIG. 2, which represents a horizontal cross section through the housing 2 in the sub-area 30, the supply air becomes in the course of its

Transfer from the air line 11 into the intermediate space 9 is deflected by means of an air guide element 37 such that the main flow direction 16 of the supply air is tangential

Receives flow component. This leads to the supply air starting from the

Passage opening 22 executes a circular flow within the intermediate space 9, which flows around the inner wall 7. The transfer openings 13, of which in the example shown a total of five pieces are evenly distributed around the circumference of the inner wall 7 (in each case offset by 72 °), finally allow the supply air to pass into the combustion chamber 3. The transfer openings are thereby 13 in the form of horizontally aligned slots, which form a flow resistance for the supply air. In this way, the transfer openings 13 act as throttles, which lead to a local increase in the flow velocity of the supply air in the course of the transfer into the

Guide combustion chamber 3. The transfer openings 13 in turn also participate

Air guiding elements 32 together, which have a tangential inflow of the supply air into the

Ensure combustion chamber 3. Due to the oxygen requirement of the fire 25, the supply air is finally “sucked” into the fire 25, as it were, by means of a vacuum formed in the area of the fire 25. A tangential flow direction of the supply air is maintained until the very end.

In an alternative embodiment, which is shown in FIGS. 3 and 4, the main difference from the embodiment according to FIGS. 1 and 2 is that the supply air, starting from the intermediate space 9, directly into the combustion chamber 3 by means of the air line 11 is initiated. For this purpose, the air line 11 is initially led away from the air outlet opening 12 in the lower end section 15 of the housing 2 away from the housing 2 and then penetrates the outer wall 8 in the region of a

Passage opening 22. The air line 11 then extends from the passage opening 22 through the intermediate space 9 and ends at one

Transition cross section 13 to which the second end 19 of the air line 11 is connected.

The air line 11 therefore comprises an outer section 21 extending outside the housing 2 and an inner section 20 extending inside the housing 2 (more precisely: within the intermediate space 9). The configuration has the consequence that the spiral main flow direction 16 prevailing in the intermediate space 9 Supply air is interrupted or cut off because the supply air is forced into the air line 11, which forces the supply air to flow within the air line 11. The housing 2 is also closed in its lower end section 15, so that the supply air can escape from the intermediate space 9 solely through the air line 11. through the air line 11 which, as described here, directly to the combustion chamber 3

is connected, in the course of the flow of the supply air from the air line 11 into the combustion chamber 3, the possibility is given to control the main flow direction 16 of the supply air in the desired manner. In particular, it is conceivable to connect the air line 11 obliquely relative to the inner wall 7 to the latter such that the main flow direction 16 of the supply air is oriented at an angle 35 with respect to the transition cross section 13. The angle 35 here is approximately 60 °, the supply air being tangential

Flow component is impressed. This means that the supply air flows round or “swirls” around the burner plate 27, which has proven to be particularly advantageous for the combustion of highly compressed fuels.

[38] In principle, regardless of the direct connection of the air line 11 to the inner wall 7, the intermediate space 9 is formed in the second exemplary embodiment with a constant cross section over the entire height of the housing 2. The generation of a spiral flow in the area of the intermediate space 9 is achieved here at least initially by means of an inclined position of the air duct 6 relative to the outer wall 8. This inclined division is designed such that the main flow direction 16 of the supply air oriented parallel to the central axis 24 of the air duct 6 forms an angle 17 with a plane of the air inlet opening 10, which here is approximately 70 °. In this way, the supply air can already be introduced into the intermediate space 9 with a tangential flow component, and due to the arrangement of the air outlet opening 12 in the lower end section 15 of the housing 2, a downward flow of the supply air also occurs. As a result, the desired spiral flow characteristic of the supply air is obtained from the air inlet opening 10 to the air outlet opening 12

LIST OF REFERENCE NUMBERS

1 burner

2 housings

3 combustion chamber

4 supply line

5 derivative

6 air duct

7 inner wall

8 outer wall

9 space

10 Air inlet opening 1 1 air line

12 air outlet opening

13 transition opening 14 upper end section

15 lower end section

16 main flow direction

17 angles

18 first end

19 second end

20 interior section

21 outer section 22 through opening 23 surroundings

24 central axis

25 fires

26 air guiding element

27 burner plates 28 intermediate shelf

29 upper area

30 sub-area

31 air guiding element 32 air guiding element

33 narrow range

34 wide range

35 angles

36 blanket

37 air guiding element

Claims

claims

1. Method for operating a combustion device (1), comprising the combustion device (1)

at least one combustion chamber (3) arranged in a double-walled housing (2),

at least one feed line (4) for feeding a fuel into the combustion chamber (3),

at least one discharge line (5) for discharging exhaust air from the combustion chamber (3),

at least one air duct (6) for supplying supply air into the

Housing (2),

wherein the housing (2) comprises an inner wall (7) and an outer wall (8) which delimit an intermediate space (9) between them, an air inlet opening (10) being arranged in an upper end section (14) of the outer wall (8) which interacts with the air duct (6) so that supply air can be introduced into the intermediate space (9) by means of the air duct (6),

wherein the intermediate space (9) and the combustion chamber (3) enclosed by the inner wall (7) are connected to one another in terms of flow technology, so that the supply air introduced into the intermediate space (9) can be transferred into the combustion chamber (3),

comprising the following process steps:

a) By means of the air duct (6), supply air is introduced into the upper end section (14) of the housing (2).

b) The supply air is in the direction of a space (9)

lower end portion (15) of the housing (2) passed. c) The supply air is introduced into the combustion chamber (3),

characterized by the following process steps:

d) The supply air is by means of an air line (1 1), which with a in the

Outside wall (8) arranged air outlet opening (12)

interacts, first out of the housing (2) and then at least indirectly fed to the combustion chamber (3).

2. The method according to claim 1, characterized in that the intermediate space (9) by means of an intermediate floor (28) in the lower end section (15) is divided into an upper region (29) and a lower region (30), the supply air being exclusively by means of Air line (11) is guided starting from the upper region (29) into the lower region (30) of the intermediate space (9).

3. The method according to claim 2, characterized in that the supply air starting from the sub-area (30) of the intermediate space (9) through at least one transition opening (13), preferably through a plurality of

Transfer openings (13) through which the combustion chamber (3) is fed.

4. The method according to any one of claims 1 to 3, characterized in that the supply air is deflected in the course of the passage into the combustion chamber (3) by means of at least one air guide element (32), wherein preferably a tangential flow component is impressed on the supply air.

5. The method according to any one of claims 1 to 4, characterized in that the supply air in the course of the flow from the air inlet opening (10) to the

Air outlet opening (12) of the outer wall (8) spirally around the

Inner wall (7) is guided around.

6. The method according to claim 5, characterized in that the supply air is deflected by means of at least one air guide element (26, 31) within the intermediate space (9), so that the spiral flow is established.

7. The method according to any one of claims 1 to 6, characterized in that the supply air - viewed in a horizontal sectional plane of the combustion device (1) - is introduced into the intermediate space (9) with a tangential directional component, preferably a main flow direction (16) Inlet air with the outer wall (8) in the area of the air inlet opening (10) encloses an angle (17) in the area between 60 ° and 90 °, preferably between 70 ° and 90 °, further preferably between 80 ° and 90 °.

8. Combustion device (1), in particular for the combustion of pellets produced from regenerative substances, comprising

at least one combustion chamber (3) arranged in a double-walled housing (2), at least one feed line (4) for feeding a fuel into the combustion chamber (3),

at least one discharge line (5) for discharging exhaust air from the

Combustion chamber (3),

at least one air duct (6) for supplying supply air into the

Housing (2),

wherein the housing (2) comprises an inner wall (7) and an outer wall (8) which delimit an intermediate space (9) between them, one in an upper end section (14) of the outer wall (8)

Air inlet opening (10) is arranged, which interacts with the air duct (6), so that supply air can be introduced into the intermediate space (9) by means of the air duct (6),

marked by

an air line (11) which cooperates with its first end (18) with an air outlet opening (12) arranged in a lower end section (15) of the housing (2) in the outer wall (8),

wherein at least one outer section (21) of the air line (1 1) extends outside the housing (2),

the supply air by means of the air line (1 1) starting from the

Air outlet opening (12) can be fed at least indirectly to the combustion chamber (3).

9. Burning device (1) according to claim 8, characterized by a

Intermediate floor (28) by means of which the intermediate space (9) is divided into an upper region (29) and a lower region (30), preferably the

Air outlet opening (12) is arranged in the upper area (29) and the supply air by means of the air line (11) starting from the upper area (29)

Sub-area (30) is too conductive.

10. Burner (1) according to claim 9, characterized in that the

Inner wall (7) has a plurality of transition openings (13) by means of 20 of which a fluidic connection between the sub-area (30) of the intermediate space (9) and the combustion chamber (3) is established.

1 1. Burning device (1) according to one of claims 8 to 10, characterized

characterized in that the outer wall (8) has a passage opening (22) through which the supply air by means of the air duct (11) into the

Interspace (9) is feasible.

12 combustion device (1) according to one of claims 8 to 11, characterized

characterized in that a central axis (24) of the air duct (6) - viewed in a horizontal sectional plane - with the outer wall (8) in the area of the air inlet opening (10) forms an angle (17) in the area between 60 ° and 90 °, preferably between 70 ° and 90 °, more preferably between 80 ° and 90 °.

13. Combustion device (1) according to one of claims 8 to 12, characterized by a plurality of air guide elements (26, 31) which are arranged in the intermediate space (9), preferably at least one of the air guide elements (31), preferably all of the air guide elements ( 31), are arranged on the inner wall (7).

14. Burning device (1) according to claim 13, characterized in that

at least one air guide element (26, 31), preferably all air guide elements (26, 31), are formed by plate-shaped guide plates.

15. Burning device (1) according to one of claims 8 to 14, characterized

characterized in that the space (9) is divided into a wide area (34) and a narrow area (33), a horizontally measured extent of the space (9) in the wide area (34) being greater than in the narrow area (33).

16. Combustion device (1) according to claim 15, characterized in that the air inlet opening (10) with the wide area (34) and the air outlet opening (12) cooperate with the narrow area (33).