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EP0114219B1 - Furnace for straw or similar material - Google Patents

Furnace for straw or similar material Download PDF

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Publication number
EP0114219B1
EP0114219B1 EP83111204A EP83111204A EP0114219B1 EP 0114219 B1 EP0114219 B1 EP 0114219B1 EP 83111204 A EP83111204 A EP 83111204A EP 83111204 A EP83111204 A EP 83111204A EP 0114219 B1 EP0114219 B1 EP 0114219B1
Authority
EP
European Patent Office
Prior art keywords
combustion chamber
air
combustion
baffle plate
floor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP83111204A
Other languages
German (de)
French (fr)
Other versions
EP0114219A2 (en
EP0114219A3 (en
Inventor
Jürgen Simonis
Hans-Otto Dr.-Ing. Sacht
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Gebrueder Welger GmbH and Co KG
Original Assignee
Gebrueder Welger GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19823247484 external-priority patent/DE3247484A1/en
Application filed by Gebrueder Welger GmbH and Co KG filed Critical Gebrueder Welger GmbH and Co KG
Priority to AT83111204T priority Critical patent/ATE24237T1/en
Publication of EP0114219A2 publication Critical patent/EP0114219A2/en
Publication of EP0114219A3 publication Critical patent/EP0114219A3/en
Application granted granted Critical
Publication of EP0114219B1 publication Critical patent/EP0114219B1/en
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23M—CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR
    • F23M9/00—Baffles or deflectors for air or combustion products; Flame shields
    • F23M9/02—Baffles or deflectors for air or combustion products; Flame shields in air inlets
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23B—METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B1/00—Combustion apparatus using only lump fuel
    • F23B1/30—Combustion apparatus using only lump fuel characterised by the form of combustion chamber
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
    • F23G7/10—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of field or garden waste or biomasses

Definitions

  • the invention relates to a firing system according to the preamble of claim 1.
  • a furnace for straw with a tubular combustion chamber is known from EP-A-38962.
  • two vortex flows are to be generated by individually spaced nozzles, which are arranged in the combustion chamber floor on both sides of the vertical combustion chamber central plane.
  • the manufacture of the combustion chamber with individual nozzles and air baffles for each individual nozzle is relatively complex and requires welding work which can only be carried out to a limited extent on the highly heat-resistant material.
  • the object of the present invention is to improve the combustion chamber in such a way that more uniform combustion of the straw strand is achieved with little design effort and the feed resistance of the ember bed in the combustion chamber is reduced.
  • the object is achieved according to the invention in that the swirl movements are generated by a baffle plate under the ember bed, which completely overlaps air supply openings arranged in the combustion chamber floor and extending in the longitudinal direction of the combustion chamber, so that a gap for the lateral outflow of the combustion air is formed between the baffle plate and the combustion chamber floor, the lateral Air outflow also has a fluidized bed effect on the ember bed.
  • Another advantage of the side air flow on both sides of the baffle plate is that in the area where the ember bed protrudes laterally beyond the baffle plate, the air layer between the ember bed and the combustion chamber floor forms a kind of fluid bed for the ember bed, which reduces the axial feed resistance of the ember bed.
  • the thus reduced wall friction of the ember bed allows the ember bed to "flow" through the combustion chamber without the embers bed becoming stuck, breaking open and sliding over one another, thereby reliably preventing the combustion chamber from becoming blocked.
  • a downwardly directed nozzle row is arranged above the baffle plate region in the combustion chamber ceiling of the combustion chamber region on the feed pipe side.
  • this row of nozzles serves to supply additional combustion air in the initial area of the combustion chamber, in which most of the carbonization gases are released; on the other hand, blowing in the combustion air, for example in the vertical axis of the combustion chamber, supports early insertion and complete formation of the two vortex flows.
  • a favorable embodiment of the subject matter of the invention is further achieved in that nozzle rows arranged in the combustion chamber floor and extending approximately over the entire length of the combustion chamber are only overlapped by the baffle plate by up to half the length of the combustion chamber.
  • the embers bed which has only a small amount of combustion air flowing through them from below in the baffle plate area, is subjected to intense air from below after the baffle plate area and the fuel is burned out.
  • the invention further proposes that the width of the baffle plate corresponds to approximately one sixth of the combustion chamber inner jacket circumference and that the baffle plate is designed as an easily removable sheet metal shell made of heat-resistant steel which is adapted to the shape of the combustion chamber base and which is kept at a distance from the combustion chamber base by supporting elements and is secured against shifting in the fuel thrust direction.
  • the baffle plate can be easily removed to clean the gap and is also easy to replace after wear. No welding work is required on the combustion tube itself to form the nozzle, but only simple drilling or punching work.
  • the combustion chamber consists of a cylindrical outer jacket which encloses a frustoconical inner jacket made of high-temperature steel, an annular space through which combustion air can flow is formed between the outer jacket and the inner jacket, which is connected to a compressed air blower at the combustion chamber inlet and is closed at the combustion chamber outlet, whereby the inner jacket is slidable and removable relative to a feed pipe.
  • This configuration avoids thermal stresses within the combustion chamber and the formation of cracks.
  • the manufacture of the combustion chamber and maintenance e.g. B. cleaning and replacing the fuel tube, very simplified.
  • the cross-section of the combustion chamber is reduced in the direction of fuel thrust.
  • the combustion chamber 2 is formed by a cylindrical outer jacket 3, into which a feed pipe 4 projects.
  • the outer jacket 3 has approximately twice the diameter of the feed tube 4 and lies with its central axis inclined downwards relative to the approximately horizontal feed tube 4.
  • the outer jacket 3 is supported by a vertical end plate 5 and is closed off in the axial direction by this end plate 5 outside the circumference of the feed tube.
  • the outer jacket 3 has a recess 6, into which a compressed air blower 7 opens.
  • a somewhat shorter hollow truncated cone-shaped inner jacket 8 is arranged inside the outer jacket 3.
  • the feed pipe 4 projects into the large opening 9 of the inner casing 8 at a short distance above the underside of the inner casing, which forms a combustion chamber floor 10.
  • the small opening of the inner casing 8 closes approximately with the outer casing 3 and forms an open combustion chamber outlet 13.
  • the inner casing underside runs parallel to the outer casing 3 at a distance, so that an air-flowable annular space 11 remains between the inner casing 8 and the outer casing 3.
  • An end plate 12 closes the large opening 9 outside the circumference of the feed tube.
  • the end plate 12 carries the inner jacket 8 and has a somewhat larger inner diameter than the feed tube 4, so that the inner jacket 8 with the end plate 12 can be displaced on the feed tube 4.
  • the inner jacket 8 encloses an annular disk 14.
  • the annular disk 14 covers the annular chamber 11 on the combustion chamber outlet side, on the one hand, and on the other hand it serves to fasten the inner jacket 8 to the outer jacket 3.
  • the annular disk 14 is at the outer circumference by 90 ° to the front flanged, and this flanged edge 15 is pushed into the outer jacket 3.
  • a fastening element 16 passes through the outer jacket 3 and the flanged edge 15 above and below. After the fastening elements 16 have been removed, the inner jacket 8 can be pulled out of the outer jacket 3.
  • the combustion air is blown into the annular space 11 by the compressed air blower 7 and enters the inner shell 8 through four nozzle sets from the annular space: a) A row of nozzles 17 extending approximately over the entire length of the combustion chamber is arranged in the combustion chamber base 10 on both sides at a distance from the vertical center axis of the combustion chamber is formed from individual holes. On the feed pipe side, these rows of nozzles 17 are completely overlapped by a baffle plate 18 over approximately% of the combustion chamber length.
  • the baffle plate 18 consists of a sheet metal shell made of highly heat-resistant steel which is adapted to the shape of the combustion chamber base 10, has a width which corresponds to approximately one sixth of the inner jacket circumference and has lateral interlocks 19 as supporting elements which keep the metal shell at a distance of approximately 2 mm from the combustion chamber base 10 , so that a gap 20 is formed between the baffle plate 18 and the combustion chamber floor 10.
  • the baffle plate 18 deflects the air jets flowing through the nozzle rows 17 into the gap space 20 by approximately 90 ° to the lateral outflow, so that an air flow 21, 22 is formed along the circumference of the inner jacket on each combustion chamber side.
  • a row of nozzles 27 is arranged above the baffle plate 18 in the combustion chamber ceiling formed by the inner jacket 8 and extends in the vertical central plane of the combustion chamber and extends in the axial direction of the combustion chamber 2, the air jets 28 of which are directed downwards and the length of which corresponds to approximately half the length of the baffle plate .
  • the rows of nozzles 17 are uncovered up to the combustion chamber outlet 13, so that the air is blown upwards in the radial direction 30.
  • nozzles 31 are provided in the form of bores, the flow 32 of which is directed radially downward, over the upper third of the inner jacket circumference.
  • a fuel strand 33 made of compressed short straw is pushed in the fuel thrust direction 29 through the feed pipe 4 into the combustion chamber 2 and the compressed air blower 7 is switched on.
  • the fuel strand 33 burns off on the end face, while the fuel strand 33 is being advanced over the baffle plate 18 and over the Combustion chamber floor 10 forms a bed of embers 34 made of straw coal, which becomes flatter towards the combustion chamber outlet 13.
  • the row of nozzles 27 Due to the conical shape of the inner jacket 8, the row of nozzles 27 has a component directed towards the fuel strand end for the supply of combustion air.
  • the released, volatile carbonization gases rise to the top of the combustion chamber and are captured by the air swirl movements 23, 24, mixed intensively with air, and flow as burning air-carbonization gas swirl movements 23, 24 to the combustion chamber outlet 13, due to the tapering of the combustion chamber 2 are kept close to the ember bed 34.
  • the row of nozzles 27 supports the formation of the two oppositely symmetrical swirl movements 23, 24 by the vertically downward directed air jets 28.
  • the air flowing out laterally from the gap space 20 creates an air layer between the ember bed 34 and the combustion chamber floor 10, which reduces the feed resistance of the ember bed 34.
  • the ember bed 34 After the ember bed 34 is pushed over the baffle plate 18, it is flowed through from below by the radially upward air jets 30 of the nozzle rows 17, so that residual fuel parts are still burned.
  • the nozzles 31 distributed in the upper third of the inner jacket circumference serve to burn residual gas. After reaching the combustion chamber outlet 13, the embers bed 34 falls down into the ash room at the bottom of the furnace.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical & Material Sciences (AREA)
  • Sustainable Energy (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Thermal Sciences (AREA)
  • Glass Compositions (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)
  • Solid-Fuel Combustion (AREA)
  • Combustion Of Fluid Fuel (AREA)

Abstract

1. Furnace for straw or similar material, with a horizontal, tubular combustion chamber (2) projecting into a heating boiler (1), into which chamber the fuel is inserted from the outside in the axial direction and to which the combustion air is supplied from an annular space (11) on the circumferential side encasing the combustion chamber (2), the shape of the combustion chamber (2) and the arrangement of the supply of combustion air being so co-ordinated with each other that they force the combustion air and the gasified fuel components into two powerful twisting movements (23, 24) and direct them as eddy currents in the axial direction closely over an incandescent bed (34) lying on the floor (10) of the combustion chamber, characterized in that the twisting movements (23, 24) are produced by a baffle plate (18) underneath the incandescent bed (34), which plate completely overlaps air supply openings (17) which are arranged in the combustion chamber floor (10) and run in the longitudinal direction of the combustion chamber, so that between the baffle plate (18) and the combustion chamber floor (10) a clearance space (20) is formed for the combustion air to flow out laterally, the lateral air outflow (21, 22) additionally exerting a fluidized bed effect on the incandescent bed (34).

Description

Die Erfindung bezieht sich auf eine Feuerungsanlage nach dem Oberbegriff des Patentanspruches 1.The invention relates to a firing system according to the preamble of claim 1.

Eine Feuerungsanlage für Stroh mit rohrförmiger Brennkammer ist aus der EP-A-38962 bekannt. Beim Gegenstand der am 13.1.83 veröffentlichten DE-A-3126419 sollen zwei Wirbelströmungen durch einzelne beabstandete Düsen erzeugt werden, die im Brennkammerboden beidseits der vertikalen Brennkammermittelachsebene angeordnet sind. Mit dieser Ausgestaltung werden zwar schon relativ gute Verbrennungsergebnisse erzielt, es hat sich jedoch gezeigt, dass der Strohstrang im Bereich jeder Einzeldüse intensiver verbrannt wird als im Raum zwischen den Düsen. Ferner ist die Herstellung der Brennkammer mit Einzeldüsen und Luftleitblechen für jede Einzeldüse relativ aufwendig und bedingt Schweissarbeiten, die an dem hochhitzebeständigen Material nur begrenzt durchführbar sind. Der vorliegenden Erfindung liegt die Aufgabe zugrunde, die Brennkammer so zu verbessern, dass mit geringem konstruktivem Aufwand eine gleichmässigere Verbrennung des Strohstranges erreicht und der Vorschubwiderstand des Glutbettes in der Brennkammer verringert wird.A furnace for straw with a tubular combustion chamber is known from EP-A-38962. In the subject of DE-A-3126419 published on January 13, 1983, two vortex flows are to be generated by individually spaced nozzles, which are arranged in the combustion chamber floor on both sides of the vertical combustion chamber central plane. With this configuration, relatively good combustion results are achieved, but it has been shown that the straw strand is burned more intensively in the area of each individual nozzle than in the space between the nozzles. Furthermore, the manufacture of the combustion chamber with individual nozzles and air baffles for each individual nozzle is relatively complex and requires welding work which can only be carried out to a limited extent on the highly heat-resistant material. The object of the present invention is to improve the combustion chamber in such a way that more uniform combustion of the straw strand is achieved with little design effort and the feed resistance of the ember bed in the combustion chamber is reduced.

Die Aufgabe wird erfindungsgemäss dadurch gelöst, dass die Drallbewegungen durch eine Prallplatte unter dem Glutbett erzeugt werden, welche im Brennkammerboden angeordnete und in Brennkammerlängsrichtung verlaufende Luftzuführöffnungen vollständig überlappt, so dass zwischen Prallplatte und Brennkammerboden ein Spaltraum zur seitlichen Ausströmung der Verbrennungsluft gebildet wird, wobei die seitliche Luftausströmung zusätzlich einen Fliessbetteffekt auf das Glutbett ausübt.The object is achieved according to the invention in that the swirl movements are generated by a baffle plate under the ember bed, which completely overlaps air supply openings arranged in the combustion chamber floor and extending in the longitudinal direction of the combustion chamber, so that a gap for the lateral outflow of the combustion air is formed between the baffle plate and the combustion chamber floor, the lateral Air outflow also has a fluidized bed effect on the ember bed.

Durch diese erfindungsgemässe Ausbildung der Brennkammer wird beidseits der Prallplatte entlang deren gesamter Länge eine kontinuierliche Ausströmung der Verbrennungsluft erzielt und damit eine gleichmässige Luftdurchströmung und Verbrennung des Strohstranges gewährleistet. Die beidseits der Prallplatte austretenden Luftströmungen treffen im oberen Brennkammerbereich frontal gegeneinander, wodurch sie etwa um 90° nach unten abgelenkt und in zwei kräftige, entgegengesetzt symmetrische Rotationswirbel gezwungen werden. Dadurch wird die im oberen Brennkammerbereich besonders heisse Luft mit den vom Glutbett aufsteigenden Schwelgasen intensiv vermischt, wodurch die beiden wichtigen Voraussetzungen für eine gute Verbrennung der Schwelgase, nämlich gute Durchmischung der Schwelgase mit Verbrennungsluft bei gleichzeitig hoher Verbrennungstemperatur, auf konstruktiv einfache Weise verwirklicht werden können. Einen weiteren Vorteil bietet die seitliche Luftausströmung beidseits der Prallplatte dadurch, dass in dem Bereich, in dem das Glutbett seitlich über die Prallplatte hinausragt, die Luftschicht zwischen Glutbett und Brennkammerboden eine Art Fliessbett für das Glutbett bildet, wodurch der axiale Vorschubwiderstand des Glutbettes verringert wird. Die so verminderte Wandreibung des Glutbettes lässt das Glutbett durch die Brennkammer «fliessen», ohne dass ein Festsetzen, Aufbrechen und Übereinanderschieben des Glutbettes stattfindet, wodurch das Verstopfen der Brennkammer sicher verhindert wird.Through this design of the combustion chamber according to the invention, a continuous outflow of the combustion air is achieved on both sides of the baffle plate along its entire length and thus a uniform air flow and combustion of the straw strand is ensured. The air currents emerging on both sides of the baffle plate meet head-on in the upper combustion chamber area, causing them to be deflected downwards by about 90 ° and forced into two powerful, oppositely symmetrical rotary vortices. As a result, the particularly hot air in the upper combustion chamber area is mixed intensively with the carbonization gases rising from the ember bed, which means that the two important requirements for good combustion of the carbonization gases, namely thorough mixing of the carbonization gases with combustion air and at the same time high combustion temperature, can be achieved in a structurally simple manner. Another advantage of the side air flow on both sides of the baffle plate is that in the area where the ember bed protrudes laterally beyond the baffle plate, the air layer between the ember bed and the combustion chamber floor forms a kind of fluid bed for the ember bed, which reduces the axial feed resistance of the ember bed. The thus reduced wall friction of the ember bed allows the ember bed to "flow" through the combustion chamber without the embers bed becoming stuck, breaking open and sliding over one another, thereby reliably preventing the combustion chamber from becoming blocked.

In einer bevorzugten Ausgestaltung der Erfindung ist oberhalb des Prallplattenbereiches in der Brennkammerdecke des zuführrohrseitigen Brennkammerbereiches eine nach unten gerichtete, etwa in der vertikalen Brennkammermittelachsebene gelegene und sich in axialer Richtung der Brennkammer erstreckende Düsenreihe angeordnet. Einerseits dient diese Düsenreihe dazu, im Anfangsbereich der Brennkammer, in dem der Grossteil der Schwelgase freigesetzt wird, zusätzlich Verbrennungsluft zuzuführen, andererseits unterstützt das Einblasen der Verbrennungsluft etwa in der vertikalen Brennkammermittelachsebene ein frühzeitiges Einsetzen und eine vollständige Ausbildung der beiden Wirbelströmungen.In a preferred embodiment of the invention, above the baffle plate region in the combustion chamber ceiling of the combustion chamber region on the feed pipe side, a downwardly directed nozzle row, approximately in the vertical axis of the combustion chamber and extending in the axial direction of the combustion chamber, is arranged. On the one hand, this row of nozzles serves to supply additional combustion air in the initial area of the combustion chamber, in which most of the carbonization gases are released; on the other hand, blowing in the combustion air, for example in the vertical axis of the combustion chamber, supports early insertion and complete formation of the two vortex flows.

Eine günstige Ausgestaltung des Erfindungsgegenstandes wird ferner dadurch erreicht, dass im Brennkammerboden angeordnete und sich etwa über die gesamte Brennkammerlänge erstreckende Düsenreihen nur etwa bis zur Hälfte der Brennkammerlänge von der Prallplatte überlappt werden. Dadurch wird das Glutbett, welches im Prallplattenbereich von unten nur wenig mit Verbrennungsluft durchströmt wird, im Anschluss an den Prallplattenbereich intensiv von unten mit Luft beaufschlagt und das Brennmaterial ausgebrannt.A favorable embodiment of the subject matter of the invention is further achieved in that nozzle rows arranged in the combustion chamber floor and extending approximately over the entire length of the combustion chamber are only overlapped by the baffle plate by up to half the length of the combustion chamber. As a result, the embers bed, which has only a small amount of combustion air flowing through them from below in the baffle plate area, is subjected to intense air from below after the baffle plate area and the fuel is burned out.

Die Erfindung schlägt ferner vor, dass die Breite der Prallplatte etwa einem Sechstel des Brennkammer-Innenmantelumfanges entspricht und dass die Prallplatte als eine leicht herausnehmbare, der Form des Brennkammerbodens angepasste Blechschale aus hitzebeständigem Stahl ausgebildet ist, welche durch Stützelemente auf Abstand zum Brennkammerboden gehalten wird und gegen Verschieben in Brennstoffschubrichtung gesichert ist. Die Prallplatte lässt sich zum Reinigen des Spaltraumes leicht entnehmen und ist ausserdem nach Verschleiss einfach ersetzbar. Am Brennrohr selbst sind zur Düsenbildung keine Schweissarbeiten notwendig, sondern nur einfache Bohr- oder Stanzarbeiten.The invention further proposes that the width of the baffle plate corresponds to approximately one sixth of the combustion chamber inner jacket circumference and that the baffle plate is designed as an easily removable sheet metal shell made of heat-resistant steel which is adapted to the shape of the combustion chamber base and which is kept at a distance from the combustion chamber base by supporting elements and is secured against shifting in the fuel thrust direction. The baffle plate can be easily removed to clean the gap and is also easy to replace after wear. No welding work is required on the combustion tube itself to form the nozzle, but only simple drilling or punching work.

In vorteilhafter Weise besteht die Brennkammer aus einem zylindrischen Aussenmantel, der einen hohlkegelstumpfförmigen Innenmantel aus hochhitzebeständigem Stahl umschliesst, wobei zwischen Aussenmantel und Innenmantel ein von Verbrennungsluft durchströmbarer Ringraum gebildet wird, der am Brennkammereingang mit einem Druckluftgebläse in Verbindung steht und am Brennkammerausgang stirnseitig geschlossen ist, wobei der Innenmantel gegenüber einem Zuführrohr verschiebbar und herausnehmbar ausgebildet ist. Durch diese Ausgestaltung werden Wärmespannungen innerhalb der Brennkammer und damit auftretende Rissbildungen vermieden. Überdies wird die Herstellung der Brennkammer und die Wartung, z. B. Reinigen und Auswechseln des Brennrohres, sehr vereinfacht.Advantageously, the combustion chamber consists of a cylindrical outer jacket which encloses a frustoconical inner jacket made of high-temperature steel, an annular space through which combustion air can flow is formed between the outer jacket and the inner jacket, which is connected to a compressed air blower at the combustion chamber inlet and is closed at the combustion chamber outlet, whereby the inner jacket is slidable and removable relative to a feed pipe. This configuration avoids thermal stresses within the combustion chamber and the formation of cracks. Furthermore, the manufacture of the combustion chamber and maintenance, e.g. B. cleaning and replacing the fuel tube, very simplified.

Um zu gewährleisten, dass die Wirbelströmungen über die gesamte Brennkammerlänge dicht über das Glutbett geführt werden, verkleinert sich der Brennkammerquerschnitt in Brennstoffschubrichtung.In order to ensure that the eddy currents are conducted closely over the ember bed over the entire length of the combustion chamber, the cross-section of the combustion chamber is reduced in the direction of fuel thrust.

Ein Beispiel des Erfindungsgegenstandes ist in der Zeichnung dargestellt und im folgenden beschrieben. Hierbei zeigen:

  • Fig. 1 eine vertikalen Mittelschnitt durch eine erfindungsgemässe Brennkammer einer Feuerungsanlage.
  • Fig. 2 einen Querschnitt in der Schnittebene A-B.
  • Fig. 3 einen Querschnitt in der Schnittebene C-D.
An example of the subject of the invention is shown in the drawing and described below. Here show:
  • Fig. 1 is a vertical central section through a combustion chamber according to the invention of a furnace.
  • Fig. 2 shows a cross section in the sectional plane AB.
  • Fig. 3 shows a cross section in the sectional plane CD.

Von der beispielsweise in der DE-A-3126419 näher beschriebenen Feuerungsanlage, deren Heizungskessel 1 hier nur andeutungsweise dargestellt ist, wird im folgenden im wesentlichen nur die Ausbildung der Brennkammer 2 dargestellt und beschrieben.Of the firing system described in more detail, for example, in DE-A-3126419, the heating boiler 1 of which is only indicated here, essentially only the design of the combustion chamber 2 is shown and described below.

Die Brennkammer 2 wird gebildet von einem zylindrischen Aussenmantel 3, in den ein Zuführrohr 4 hineinragt. Der Aussenmantel 3 hat etwa den doppelten Durchmesser des Zuführrohres 4 und liegt mit seiner Mittelachse gegenüber dem etwa horizontalen Zuführrohr 4 nach unten geneigt. Der Aussenmantel 3 wird von einer vertikalen Stirnplatte 5 getragen und ausserhalb des Zuführrohrumfanges von dieser Stirnplatte 5 in axialer Richtung abgeschlossen. Im unteren Bereich weist der Aussenmantel 3 eine Ausnehmung 6 auf, in die ein Druckluftgebläse 7 mündet.The combustion chamber 2 is formed by a cylindrical outer jacket 3, into which a feed pipe 4 projects. The outer jacket 3 has approximately twice the diameter of the feed tube 4 and lies with its central axis inclined downwards relative to the approximately horizontal feed tube 4. The outer jacket 3 is supported by a vertical end plate 5 and is closed off in the axial direction by this end plate 5 outside the circumference of the feed tube. In the lower area, the outer jacket 3 has a recess 6, into which a compressed air blower 7 opens.

Innerhalb des Aussenmantels 3 ist ein etwas kürzerer hohlkegelstumpfförmiger Innenmantel 8 angeordnet. In die grosse Öffnung 9 des Innenmantels 8 ragt in geringem Abstand oberhalb der Innenmantelunterseite, die einen Brennkammerboden 10 bildet, das Zuführrohr 4 hinein. Die kleine Öffnung des Innenmantels 8 schliesst etwa mit dem Aussenmantel 3 ab und bildet einen offenen Brennkammerausgang 13. Die Innenmantelunterseite verläuft mit Abstand parallel zum Aussenmantel 3, so dass zwischen Innenmantel 8 und Aussenmantel 3 auf dem ganzen Umfang ein von Luft durchströmbarer Ringraum 11 verbleibt.A somewhat shorter hollow truncated cone-shaped inner jacket 8 is arranged inside the outer jacket 3. The feed pipe 4 projects into the large opening 9 of the inner casing 8 at a short distance above the underside of the inner casing, which forms a combustion chamber floor 10. The small opening of the inner casing 8 closes approximately with the outer casing 3 and forms an open combustion chamber outlet 13. The inner casing underside runs parallel to the outer casing 3 at a distance, so that an air-flowable annular space 11 remains between the inner casing 8 and the outer casing 3.

Eine Stirnplatte 12 verschliesst ausserhalb des Zuführrohrumfanges die grosse Öffnung 9. Die Stirnplatte 12 trägt den Innenmantel 8 und besitzt einen etwas grösseren Innendurchmesser als das Zuführrohr 4, so dass der Innenmantel 8 mit der Stirnplatte 12 auf dem Zuführrohr 4 verschiebbar ist. Kurz vor dem Brennkammerausgang 13 umschliesst den Innenmantel 8 eine Ringscheibe 14. Die Ringscheibe 14 deckt einerseits den Ringraum 11 brennkammerausgangsseitig ab, und andererseits dient sie als Befestigung des Innenmantels 8 am Aussenmantel 3. Zur Befestigung ist die Ringscheibe 14 am Aussenumfang um 90° nach vorn gebördelt, und dieser Bördelrand 15 ist in den Aussenmantel 3 geschoben. Oben und unten durchsetzt den Aussenmantel 3 und den Bördelrand 15 jeweils ein Befestigungselement 16. Nach Entfernen der Befestigungselemente 16 lässt sich der Innenmantel 8 aus dem Aussenmantel 3 herauszeihen.An end plate 12 closes the large opening 9 outside the circumference of the feed tube. The end plate 12 carries the inner jacket 8 and has a somewhat larger inner diameter than the feed tube 4, so that the inner jacket 8 with the end plate 12 can be displaced on the feed tube 4. Shortly before the combustion chamber outlet 13, the inner jacket 8 encloses an annular disk 14. The annular disk 14 covers the annular chamber 11 on the combustion chamber outlet side, on the one hand, and on the other hand it serves to fasten the inner jacket 8 to the outer jacket 3. For fastening, the annular disk 14 is at the outer circumference by 90 ° to the front flanged, and this flanged edge 15 is pushed into the outer jacket 3. A fastening element 16 passes through the outer jacket 3 and the flanged edge 15 above and below. After the fastening elements 16 have been removed, the inner jacket 8 can be pulled out of the outer jacket 3.

Die Verbrennungsluft wird vom Druckluftgebläse 7 in den Ringraum 11 geblasen und tritt aus dem Ringraum in den Innenmantel 8 durch vier Düsensätze ein: a) Im Brennkammerboden 10 ist beidseits im Abstand zur vertikalen Brennkammermittelachsebene eine sich etwa über die gesamte Brennkammerlänge erstreckende Düsenreihe 17 angeordnet, die aus Einzelbohrungen gebildet wird. Zuführrohrseitig werden diese Düsenreihen 17 über etwa % der Brennkammerlänge von einer Prallplatte 18 vollständig überlappt. Die Prallplatte 18 besteht aus einer der Form des Brennkammerbodens 10 angepassten Blechschale aus hochhitzebeständigem Stahl, besitzt eine Breite, die etwa einem Sechstel des Innenmantelumfanges entspricht und weist seitliche Verschränkungen 19 als Stützelemente auf, die die Blechschale auf einen Abstand von etwa 2mm zum Brennkammerboden 10 halten, so dass zwischen Prallplatte 18 und Brennkammerboden 10 ein Spaltraum 20 gebildet wird. Die Prallplatte 18 lenkt die durch die Düsenreihen 17 in den Spaltraum 20 einströmenden Luftstrahlen etwa um 90° zur seitlichen Ausströmung um, so dass sich auf jeder Brennkammerseite eine Luftströmung 21, 22 entlang des Innenmantelumfanges bildet. Die Luftströmungen 21, 22 treffen im oberen Brennkammerbereich frontal gegeneinander, wodurch diese etwa um 90° nach unten abgelenkt und in zwei kräftige, entgegengesetzt symmetrische Drallbewegungen 23, 24 gezwungen werden, die als axiale Rotationswirbel zum Brennkammerausgang 13 strömen. Um eine Verschiebung der Prallplatte 18 gegenüber dem Brennkammerboden 10 zu vermeiden, greift ein an der Prallplatte 18 befestigter, nach unten gerichteter Zapfen 25 in eine Bohrung 26 im Brennkammerboden 10 ein. b) Im zuführrohrseitigen Brennkammerbereich ist oberhalb der Prallplatte 18 in der vom Innenmantel 8 gebildeten Brennkammerdecke eine in der vertikalen Brennkammermittelachsebene gelegene und in axialer Richtung der Brennkammer 2 verlaufende Düsenreihe 27 angeordnet, deren Luftstrahlen 28 nach unten gerichtet sind und deren Länge etwa der halben Prallplattenlänge entspricht. c) In Brennstoffschubrichtung 29 gesehen hinter der Prallplatte 18 sind die Düsenreihen 17 bis zum Brennkammerausgang 13 hin unbedeckt, so dass die Luft in radialer Richtung 30 nach oben geblasen wird. d) In der Brennkammerdecke sind kurz vor dem Brennkammerausgang 13 über das obere Drittel des Innenmantelumfanges verteilt Düsen 31 in Form von Bohrungen vorgesehen, deren Strömung 32 radial nach unten gerichtet ist.The combustion air is blown into the annular space 11 by the compressed air blower 7 and enters the inner shell 8 through four nozzle sets from the annular space: a) A row of nozzles 17 extending approximately over the entire length of the combustion chamber is arranged in the combustion chamber base 10 on both sides at a distance from the vertical center axis of the combustion chamber is formed from individual holes. On the feed pipe side, these rows of nozzles 17 are completely overlapped by a baffle plate 18 over approximately% of the combustion chamber length. The baffle plate 18 consists of a sheet metal shell made of highly heat-resistant steel which is adapted to the shape of the combustion chamber base 10, has a width which corresponds to approximately one sixth of the inner jacket circumference and has lateral interlocks 19 as supporting elements which keep the metal shell at a distance of approximately 2 mm from the combustion chamber base 10 , so that a gap 20 is formed between the baffle plate 18 and the combustion chamber floor 10. The baffle plate 18 deflects the air jets flowing through the nozzle rows 17 into the gap space 20 by approximately 90 ° to the lateral outflow, so that an air flow 21, 22 is formed along the circumference of the inner jacket on each combustion chamber side. The air flows 21, 22 hit each other frontally in the upper combustion chamber area, thereby deflecting them downward by approximately 90 ° and forcing them into two powerful, oppositely symmetrical swirl movements 23, 24, which flow as axial swirls to the combustion chamber outlet 13. In order to avoid a displacement of the baffle plate 18 with respect to the combustion chamber base 10, a pin 25 fastened to the baffle plate 18 and directed downwards engages in a bore 26 in the combustion chamber base 10. b) In the combustion chamber area on the supply pipe side, a row of nozzles 27 is arranged above the baffle plate 18 in the combustion chamber ceiling formed by the inner jacket 8 and extends in the vertical central plane of the combustion chamber and extends in the axial direction of the combustion chamber 2, the air jets 28 of which are directed downwards and the length of which corresponds to approximately half the length of the baffle plate . c) Seen in the fuel thrust direction 29 behind the baffle plate 18, the rows of nozzles 17 are uncovered up to the combustion chamber outlet 13, so that the air is blown upwards in the radial direction 30. d) In the combustion chamber ceiling, shortly before the combustion chamber outlet 13, nozzles 31 are provided in the form of bores, the flow 32 of which is directed radially downward, over the upper third of the inner jacket circumference.

Bei der Inbetriebnahme wird ein Brennstoffstrang 33 aus komprimiertem Kurzstroh in Brennstoffschubrichtung 29 durch das Zuführrohr 4 in die Brennkammer 2 geschoben und das Druckluftgebläse 7 eingeschaltet. Nach einer Initialzündung brennt der Brennstoffstrang 33 stirnseitig ab, wobei während des Vorschiebens des Brennstoffstranges 33 über der Prallplatte 18 und über dem Brennkammerboden 10 ein Glutbett 34 aus Strohkohle ausbildet, das zum Brennkammerausgang 13 hin flacher wird. Durch die konische Form des Innenmantels 8 weist die Düsenreihe 27 eine auf die Brennstoffstrangstirnseite gerichtete Komponente zur Verbrennungsluftzufuhr auf. Während der Verbrennung steigen die freigesetzten, flüchtigen Schwelgase nach oben zur Brennkammerdekke und werden von den Luftdrallbewegungen 23, 24 erfasst, intensiv mit Luft durchmischt und strömen als brennende Luft-Schwelgas-Drallbewegungen 23, 24 zum Brennkammerausgang 13, wobei sie infolge der Verjüngung der Brennkammer 2 nahe am Glutbett 34 gehalten werden. Die Düsenreihe 27 unterstützt durch die vertikal nach unten gerichteten Luftstrahlen 28 die Bildung der beiden entgegengesetzt symmetrischen Drallbewegungen 23, 24. Die seitlich aus dem Spaltraum 20 ausströmende Luft erzeugt zwischen Glutbett 34 und Brennkammerboden 10 eine Luftschicht, die den Vorschubwiderstand des Glutbettes 34 verringert. Nachdem das Glutbett 34 über die Prallplatte 18 hinausgeschoben ist, wird es durch die radial nach oben gerichteten Luftstrahlen 30 der Düsenreihen 17 von unten durchströmt, so dass auch Restbrennstoffteile noch verbrannt werden. Die im oberen Drittel des Innenmantelumfanges verteilten Düsen 31, dienen der Restgasverbrennung. Das Glutbett 34 fällt nach Erreichen des Brennkammerausgangs 13 nach unten in den Ascheraum am Boden der Feuerungsanlage.When starting up, a fuel strand 33 made of compressed short straw is pushed in the fuel thrust direction 29 through the feed pipe 4 into the combustion chamber 2 and the compressed air blower 7 is switched on. After an initial ignition, the fuel strand 33 burns off on the end face, while the fuel strand 33 is being advanced over the baffle plate 18 and over the Combustion chamber floor 10 forms a bed of embers 34 made of straw coal, which becomes flatter towards the combustion chamber outlet 13. Due to the conical shape of the inner jacket 8, the row of nozzles 27 has a component directed towards the fuel strand end for the supply of combustion air. During the combustion, the released, volatile carbonization gases rise to the top of the combustion chamber and are captured by the air swirl movements 23, 24, mixed intensively with air, and flow as burning air-carbonization gas swirl movements 23, 24 to the combustion chamber outlet 13, due to the tapering of the combustion chamber 2 are kept close to the ember bed 34. The row of nozzles 27 supports the formation of the two oppositely symmetrical swirl movements 23, 24 by the vertically downward directed air jets 28. The air flowing out laterally from the gap space 20 creates an air layer between the ember bed 34 and the combustion chamber floor 10, which reduces the feed resistance of the ember bed 34. After the ember bed 34 is pushed over the baffle plate 18, it is flowed through from below by the radially upward air jets 30 of the nozzle rows 17, so that residual fuel parts are still burned. The nozzles 31 distributed in the upper third of the inner jacket circumference serve to burn residual gas. After reaching the combustion chamber outlet 13, the embers bed 34 falls down into the ash room at the bottom of the furnace.

Claims (6)

1. Furnace for straw or similar material, with a horizontal, tubular combustion chamber (2) projecting into a heating boiler (1), into which chamber the fuel is inserted from the outside in the axial direction and to which the combustion air is supplied from an annular space (11) on the circumferential side encasing the combustion chamber (2), the shape of the combustion chamber (2) and the arrangement of the supply of combustion air being so co-ordinated with each other that they force the combustion air and the gasified fuel components into two powerful twisting movements (23, 24) and direct them as eddy currents in the axial direction closely over an incandescent bed (34) lying on the floor (10) of the combustion chamber, characterised in that the twisting movements (23, 24) are produced by a baffle plate (18) underneath the incandescent bed (34), which plate completely overlaps air supply openings (17) which are arranged in the combustion chamber floor (10) and run in the longitudinal direction of the combustion chamber, so that between the baffle plate (18) and the combustion chamber floor (10) a clearance space (20) is formed for the combustion air to flow out laterally, the lateral air outflow (21, 22) additionally exerting a fluidized bed effect on the incandescent bed (34).
2. Furnace according to Claim 1, characterised in that above the region of the baffle plate in the combustion chamber roof of the region of the combustion chamber on the supply pipe side, a downwardly directed row of nozzles (27) is arranged, situated approximately in the vertical mid-axis plane of the combustion chamber and extending in the axial direction of the combustion chamber (2).
3. Furnace according to Claim 1 or 2, characterised in that rows of nozzles (17) which are arranged in the combustion chamber floor (10) and extend approximately over the entire length of the combustion chamber, are only overlapped by the baffle plate (18) approximately up to a half of the length of the combustion chamber.
4. Furnace according to one of Claims 1 to 3, characterised in that the width of the baffle plate (18) corresponds to approximately on sixth of the inner casing circumference of the combustion chamber and that the baffle plate (18) is constructed as an easily removable sheet metal dish of heat-resistance steel which is adapted to the shape of the combustion chamber floor (10) and which, by supporting elements (19), is held at a distance from the combustion chamber floor (10) and secured against displacement in the direction of feed of the fuel (29).
5. Furnace according to one of Claims 1 to 4, characterised in that the combustion chamber (2) consists of a cylindrical outer casing (3), which surrounds a hollow frustum-shaped inner casing (8) of highly heat-resistant steel, whereby between the outer casing (3) and the inner casing (8) an annular space (11) is formed through which combustion air can flow, and which communicates with a compressed air blower (7) at the combustion chamber inlet, and is closed at the combustion chamber outlet (13) at the front side, the inner casing (8) being constructed so as to be slidable with respect to a supply pipe (4) and removable.
6. Furnace according to one of Claims 1 to 5, characterised in that the cross-section of the combustion chamber reduces in the direction of feed of the fuel (29).
EP83111204A 1982-12-22 1983-11-10 Furnace for straw or similar material Expired EP0114219B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT83111204T ATE24237T1 (en) 1982-12-22 1983-11-10 FURNACE FOR STRAW OR SIMILAR MATERIAL.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3247484 1982-12-22
DE19823247484 DE3247484A1 (en) 1981-07-04 1982-12-22 Furnace installation for straw or similar material

Publications (3)

Publication Number Publication Date
EP0114219A2 EP0114219A2 (en) 1984-08-01
EP0114219A3 EP0114219A3 (en) 1985-08-28
EP0114219B1 true EP0114219B1 (en) 1986-12-10

Family

ID=6181419

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83111204A Expired EP0114219B1 (en) 1982-12-22 1983-11-10 Furnace for straw or similar material

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EP (1) EP0114219B1 (en)
AT (1) ATE24237T1 (en)
DE (1) DE3368319D1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2671166B1 (en) * 1990-12-28 1993-04-16 Biomasse Normandie Assoc Rgle BOILER ROOM SPECIALLY DESIGNED FOR THE COMBUSTION OF CHIPPED WOOD.
ATE285551T1 (en) * 1999-10-07 2005-01-15 Maskinfabrikken Reka As BOILER WITH COMBUSTION RETORT
SE0100662D0 (en) * 2001-02-27 2001-02-27 Haakan Thunstroem combustion device
FR2907198A1 (en) * 2006-10-12 2008-04-18 S N E Ronot BURNER WITH CEREALS
CN102269403A (en) * 2011-07-06 2011-12-07 农业部规划设计研究院 Straw fuel suspension combustion furnace
AT513896B1 (en) * 2013-01-24 2016-03-15 Otto Ing Keiml Burner for solid fuels with rotatable combustion tube
CN103836614A (en) * 2014-03-28 2014-06-04 张崇鑫 Biomass burner

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU5987580A (en) * 1980-04-16 1981-11-10 Hellzen, J.T. Arrangement for firing solid fuels
DE3016531C2 (en) * 1980-04-29 1982-10-07 Siegfried 2301 Osdorf Bieder Device for the combustion of loosely stored solids, especially compacted straw
AT386268B (en) * 1981-04-10 1988-07-25 Trunkenpolz Maschinen DEVICE FOR BURNING STRAW, WOOD SHAVINGS AND THE LIKE
DE3126419C2 (en) * 1981-07-04 1986-05-22 Gebrüder Welger GmbH & Co KG, 3340 Wolfenbüttel Firing system for straw or similar material

Also Published As

Publication number Publication date
DE3368319D1 (en) 1987-01-22
EP0114219A2 (en) 1984-08-01
ATE24237T1 (en) 1986-12-15
EP0114219A3 (en) 1985-08-28

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