EP0816759B1 - Premix burner and method of operating the burner - Google Patents

Premix burner and method of operating the burner Download PDF

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Publication number
EP0816759B1
EP0816759B1 EP97810385A EP97810385A EP0816759B1 EP 0816759 B1 EP0816759 B1 EP 0816759B1 EP 97810385 A EP97810385 A EP 97810385A EP 97810385 A EP97810385 A EP 97810385A EP 0816759 B1 EP0816759 B1 EP 0816759B1
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EP
European Patent Office
Prior art keywords
burner
fuel
flow
bore
recirculation zone
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 - Lifetime
Application number
EP97810385A
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German (de)
French (fr)
Other versions
EP0816759A3 (en
EP0816759A2 (en
Inventor
Klaus Dr. Döbbeling
Hans Peter Knöpfel
Timothy Dr. Griffin
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General Electric Switzerland GmbH
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Alstom Schweiz AG
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Publication date
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Publication of EP0816759A2 publication Critical patent/EP0816759A2/en
Publication of EP0816759A3 publication Critical patent/EP0816759A3/en
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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C9/00Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber
    • F23C9/006Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber the recirculation taking place in the combustion chamber
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C7/00Combustion apparatus characterised by arrangements for air supply
    • F23C7/002Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23DBURNERS
    • F23D11/00Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
    • F23D11/36Details, e.g. burner cooling means, noise reduction means
    • F23D11/40Mixing tubes or chambers; Burner heads
    • F23D11/402Mixing chambers downstream of the nozzle
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23DBURNERS
    • F23D17/00Burners for combustion conjointly or alternatively of gaseous or liquid or pulverulent fuel
    • F23D17/002Burners for combustion conjointly or alternatively of gaseous or liquid or pulverulent fuel gaseous or liquid fuel
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23RGENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS
    • F23R3/00Continuous combustion chambers using liquid or gaseous fuel
    • F23R3/02Continuous combustion chambers using liquid or gaseous fuel characterised by the air-flow or gas-flow configuration
    • F23R3/04Air inlet arrangements
    • F23R3/10Air inlet arrangements for primary air
    • F23R3/12Air inlet arrangements for primary air inducing a vortex
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C2202/00Fluegas recirculation
    • F23C2202/40Inducing local whirls around flame
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C2900/00Special features of, or arrangements for combustion apparatus using fluid fuels or solid fuels suspended in air; Combustion processes therefor
    • F23C2900/07002Premix burners with air inlet slots obtained between offset curved wall surfaces, e.g. double cone burners
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23DBURNERS
    • F23D2209/00Safety arrangements
    • F23D2209/20Flame lift-off / stability

Definitions

  • the invention relates to the field of combustion technology. It concerns a premix burner of the double cone type and a method of operating the burner.
  • EP 0 321 809 B1 and DE-A-4416650 describe the basic structure of a burner the double-cone design known to the invention refers.
  • This burner consists essentially of hollow, partial conical bodies that complement one another, with tangential air inlet slots and feeds for gaseous and liquid fuels where the central axes the hollow partial cone body is widening in the direction of flow Have a taper and in the longitudinal direction to each other run staggered.
  • a fuel nozzle on the burner head placed in the part cone bodies formed conical interior.
  • the gaseous fuel becomes the combustion air flow prior to its inflow into the interior of the burner arranged along the entry slots Gas injectors supplied.
  • the formation of the fuel / air mixture thus happens directly at the end of the tangential air inlet slots.
  • the entrance level of the combustion air and the gas entry level (perforation level) fall at this known prior art together.
  • the cause of the vibrations and the extinction at comparatively fuel-rich conditions is the inadequate Flame stabilization of the burner.
  • the burner will stabilized by the inner recirculation zone, which in the Head stage operation is supplied with additional fuel.
  • the outer shear layer of the fuel / air mixture emerging from the burner which has a much larger contact area between fresh gas and exhaust gas compared to the inner one Recirculation zone is available, however, so far not used for stabilization.
  • the invention seeks to remedy this. You have the task based on the well-known burner of the double cone type with simple constructive means and to change it operate in such a way that additional stabilization of the Flame occurs without causing a significant increase of pollutant emission levels is coming.
  • this is achieved in that one Burner according to the preamble of claim 1 in the burner sickle at least one bore is arranged, which the supply of gaseous fuel to the outer recirculation zone serves. According to the invention, this is the case with a method to operate the burner by approx. 3 up to 8% of the total gaseous fuel to the outside Recirculation zone can be mixed.
  • the advantages of the invention include that the flame stability is improved, i.e. there are fewer Pressure pulsations in the flame. Also draws the burner according to the invention compared to the known one State of the art due to a lower lean extinguishing limit off so that it has an expanded operating range. By intensifying the outer reaction front Another advantage is a shorter burnout length.
  • the holes under one An angle of approx. 45 ° to the burner axis is arranged obliquely outwards are. Then there is a particularly intense mix of Fuel with the exhaust gas from the outer recirculation zone possible. The same is advantageously done if the additional holes arranged in the burner sickle are that they inject the fuel in the opposite direction to the swirl direction of the exhaust gas in the recirculation zone cause.
  • FIG. 1 shows a perspective view of the inventive Burner.
  • FIG. 1 shows a perspective view of the inventive Burner.
  • the burner consists of two hollow partial cone bodies 1, 2, which are offset from one another.
  • the two partial cone bodies 1, 2 each have a cylindrical starting part 9, 10, which also run offset to each other, so that in this area too the tangential air inlet slots 5, 6 are present.
  • In this cylindrical starting part 9, 10 is a nozzle 11 for Atomization of the liquid fuel 12 housed.
  • the Burner can also without the cylindrical starting parts 9, 10th be designed so that it is purely conical. Then the fuel nozzle 11 is accommodated directly in the cone tip.
  • the two partial cone bodies 1, 2 each have one Fuel line 13, 14, which are provided with openings 15 which are fuel injectors. Through the Fuel injectors 15 becomes gaseous fuel 16 flowing through the tangential air inlet slots 5, 6 Combustion air 7 added
  • Combustion chamber side 17 has a burner as an anchor for the partial cone body 1, 2 serving front plate 18 with a Number of holes 19 through which dilution or cooling air 20 the front part of the combustion chamber 17 or its wall can be supplied.
  • liquid fuel 12 is used to operate the burner, so it flows through the nozzle 11 and is in one injected acute angle into the burner interior 17, wherein a homogeneous fuel spray is established.
  • the conical Liquid fuel profile 23 is of a tangentially flowing rotating combustion air flow 7 enclosed.
  • concentration of the liquid fuel becomes axial 12 continuously through the mixed combustion air 7 reduced.
  • the optimal fuel concentration over the Cross section is only in the area of the vertebral burst, i.e. reached in the area of the inner recirculation zone 24.
  • the Ignition occurs at the top of the inner recirculation zone 24. This is in the so-called head stage operation (not shown) supplied with additional fuel. Only at this point creates a stable flame front 25.
  • the flame stabilization results from an increase in the swirl number in the direction of flow along the cone axis. The flame strikes back enters the interior of the burner under normal operating conditions not on.
  • this outer recirculation zone is located 28 in the outer area of the combustion chamber 17, close the wall of the combustion chamber 21.
  • the holes 27 can be in different ways in the burner sickle 26 may be arranged, for example parallel to Burner axis 22. In other exemplary embodiments, they can also at an angle to the burner axis 22 of approximately 45 ° be arranged obliquely outwards, so that the additional gaseous fuel 16 injected towards the combustion chamber wall becomes. It is particularly advantageous if the bores 27 are arranged so that the additional gaseous fuel 16 in the counter-swirl direction to the recirculation flow is introduced because then a particularly intensive mixture of the additional fuel with the recirculating exhaust gas and the resulting flame stabilization is particularly high is.
  • the burner is to be operated such that only about 3 to 8% of the total gaseous fuel through the Open openings 27 into the outer recirculation zone 28. Since the cooling air 20 is already mixed in at this point and the recirculating exhaust gases are already part of theirs have given sensible heat to the front panel 18 this additional fuel addition is not worth mentioning Increase in NOx emissions. This is especially true when the injections are small enough to stabilize to avoid at the entrance beams. After Fuel is mixed in after a certain ignition delay Auto ignition and just before or directly on the outer shear layer of the emerging fuel / air mixture.
  • the invention provides an external additional stabilization (by mini pilots), which among other things to an extension the operating range of the burner and to an increased Flame stability leads.
  • FIG. 4 is a concrete embodiment in a cross section presented the invention.
  • the cross section shows the area the burner exit sickle 26.
  • In the sickle 26 are 14 Positions on the circumference with an angular division of approximately 10 ° Bores 26 arranged with a diameter of 0.8 mm.
  • the number and size of the bores 26 was chosen so that approx. 3% of the total fuel mass flow there and in the outer recirculation zone, not shown in Fig. 4 28 can be mixed.
  • the inventive Solution can also be used for burners, which consist of more than two partial cone bodies, e.g. for so-called Four slot burner.
  • the holes 27 can also both in their number and in their position in the Burner sickle 26 vary. You just have to take care that the additional fuel mass flow that goes into the outer recirculation zone is mixed in, no more than accounts for approx. 8% of the total fuel.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Gas Burners (AREA)
  • Pressure-Spray And Ultrasonic-Wave- Spray Burners (AREA)

Description

Technisches GebietTechnical field

Die Erfindung bezieht sich auf das Gebiet der Verbrennungstechnik. Sie betrifft einen Vormischbrenner der Doppelkegelbauart und ein Verfahren zum Betrieb des Brenners.The invention relates to the field of combustion technology. It concerns a premix burner of the double cone type and a method of operating the burner.

Stand der TechnikState of the art

Aus EP 0 321 809 B1 und aus DE-A-4416650 ist der prinzipielle Aufbau eines Brenners der Doppelkegelbauart bekannt, auf den sich die Erfindung bezieht. Dieser Brenner besteht im wesentlichen aus hohlen, sich zu einem Körper ergänzenden Teilkegelkörpern, mit tangentialen Lufteintrittsschlitzen und Zuführungen für gasförmige und flüssige Brennstoffe, bei dem die Mittelachsen der hohlen Teilkegelkörper eine in Strömungsrichtung sich erweiternde Kegelneigung aufweisen und in Längsrichtung zueinander versetzt verlaufen. Im von den Teilkegelkörpern gebildeten kegelförmigen Innenraum ist am Brennerkopf eine Brennstoffdüse plaziert. Der gasförmige Brennstoff wird dem Verbrennungsluftstrom vorgängig seiner Einströmung in den Brennerinnenraum über entlang der Eintrittsschlitze angeordneten Gasinjektoren zugeführt. Die Bildung des Brennstoff/Luft-Gemisches geschieht somit direkt am Ende der tangentialen Lufteintrittsschlitze. Die Eintrittsebene der Verbrennungsluft und die Gaseintrittsebene (Belochungsebene) fallen bei diesem bekannten Stand der Technik zusammen. EP 0 321 809 B1 and DE-A-4416650 describe the basic structure of a burner the double-cone design known to the invention refers. This burner consists essentially of hollow, partial conical bodies that complement one another, with tangential air inlet slots and feeds for gaseous and liquid fuels where the central axes the hollow partial cone body is widening in the direction of flow Have a taper and in the longitudinal direction to each other run staggered. In the part cone bodies formed conical interior is a fuel nozzle on the burner head placed. The gaseous fuel becomes the combustion air flow prior to its inflow into the interior of the burner arranged along the entry slots Gas injectors supplied. The formation of the fuel / air mixture thus happens directly at the end of the tangential air inlet slots. The entrance level of the combustion air and the gas entry level (perforation level) fall at this known prior art together.

Die Zunahme des Dralles entlang der Kegelachse, verbunden mit der plötzlichen Querschnittserweiterung am Brenneraustritt, führt dazu, dass sich stromab des Brenneraustrittes auf der Brennerachse eine Rückströmzone (innere Rezirkulationszone) bildet, die die Flamme stabilisiert. Erst im Staupunkt dieser inneren Rückströmzone wird die Zündung der Flamme eingeleitet.The increase in twist along the cone axis associated with the sudden cross-sectional expansion at the burner outlet, leads to the fact that downstream of the burner outlet on the Burner axis a backflow zone (inner recirculation zone) forms, which stabilizes the flame. Only at the stagnation point of this ignition of the flame is initiated in the inner backflow zone.

In bestimmten Betriebszuständen, z.B. nahe der Löschgrenze oder bei magerem Betrieb der Vormischstufe, d.h. beim Übergang zum Kopfstufenbetrieb, bei dem zwecks Anfettung des Brennstoff/Luft-Gemisches zusätzlich Pilotgas in Achsnähe des Brenners eingedüst wird (interne Pilotisierung), neigt der Brenner zu Schwingungen. Das hat wiederum zur Folge, dass der betreibbare Bereich des Brenners, also sein Stabilitätsbereich eingeschränkt wird und der Brenner frühzeitig verlöscht.In certain operating conditions, e.g. near the deletion limit or with lean operation of the premix stage, i.e. at the transition to head stage operation, in order to enrich the Fuel / air mixture additionally pilot gas near the axis of the Brenners is injected (internal pilotization), the tends Burner to vibrate. This in turn means that the operable area of the burner, i.e. its stability area is restricted and the burner extinguishes prematurely.

Die Ursache für die Schwingungen und das Verlöschen bei vergleichsweise brennstoffreichen Bedingungen ist die unzureichende Flammenstabilisierung des Brenners. Der Brenner wird zwar durch die innere Rezirkulationszone stabilisiert, die im Kopfstufenbetrieb mit Zusatzbrennstoff versorgt wird. Die äussere Scherschicht des aus dem Brenner austretenden Brennstoff/Luft-Gemisches, die eine wesentlich grössere Kontaktfläche zwischen Frischgas und Abgas im Vergleich zur inneren Rezirkulationszone zur Verfügung stellt, wird jedoch bisher nicht zur Stabilisierung benutzt.The cause of the vibrations and the extinction at comparatively fuel-rich conditions is the inadequate Flame stabilization of the burner. The burner will stabilized by the inner recirculation zone, which in the Head stage operation is supplied with additional fuel. The outer shear layer of the fuel / air mixture emerging from the burner, which has a much larger contact area between fresh gas and exhaust gas compared to the inner one Recirculation zone is available, however, so far not used for stabilization.

Darstellung der ErfindungPresentation of the invention

Hier will die Erfindung Abhilfe schaffen. Ihr liegt die Aufgabe zugrunde, den bekannten Brenner der Doppelkegelbauart mit einfachen konstruktiven Mitteln so zu verändern und ihn so zu betreiben, dass eine zusätzliche Stabilisierung der Flamme erfolgt, ohne dass es zu einer nennenswerten Erhöhung der Schadstoffemissionswerte kommt.The invention seeks to remedy this. You have the task based on the well-known burner of the double cone type with simple constructive means and to change it operate in such a way that additional stabilization of the Flame occurs without causing a significant increase of pollutant emission levels is coming.

Erfindungsgemäss wird dies dadurch erreicht, dass bei einem Brenner gemäss dem Oberbegriff des Anspruchs 1 in der Brennersichel mindestens eine Bohrungen angeordnet ist, welche der Zufuhr von gasförmigem Brennstoff in die äussere Rezirkulationszone dient. Erfindungsgemäss wird dies bei einem Verfahren zum Betrieb des Brenners dadurch erreicht, dass ca. 3 bis 8% des gesamten gasförmigen Brennstoffes in die äussere Rezirkulationszone eingemischt werden.According to the invention this is achieved in that one Burner according to the preamble of claim 1 in the burner sickle at least one bore is arranged, which the supply of gaseous fuel to the outer recirculation zone serves. According to the invention, this is the case with a method to operate the burner by approx. 3 up to 8% of the total gaseous fuel to the outside Recirculation zone can be mixed.

Die Vorteile der Erfindung bestehen unter anderem darin, dass die Flammenstabilität verbessert wird, d.h. es treten geringere Druckpulsationen in der Flamme auf. Ausserdem zeichnet sich der erfindungsgemässe Brenner gegenüber dem bekannten Stand der Technik durch eine niedrigere magere Löschgrenze aus, so dass er einen erweiterten Betriebsbereich aufweist. Durch die Intensivierung der äusseren Reaktionsfront ergibt sich als weiterer Vorteil eine verkürzte Ausbrandlänge.The advantages of the invention include that the flame stability is improved, i.e. there are fewer Pressure pulsations in the flame. Also draws the burner according to the invention compared to the known one State of the art due to a lower lean extinguishing limit off so that it has an expanded operating range. By intensifying the outer reaction front Another advantage is a shorter burnout length.

Es ist besonders zweckmässig, wenn die Bohrungen parallel zur Brennerachse ausgerichtet sind, weil diese Ausführung sehr einfach zu realisieren ist.It is particularly useful if the holes parallel to Burner axis are aligned because this version is very is easy to implement.

Ferner ist es vorteilhaft, wenn die Bohrungen unter einem Winkel von ca. 45° zur Brennerachse schräg nach aussen angeordnet sind. Dann ist eine besonders intensive Mischung des Brennstoffes mit dem Abgas der äusseren Rezirkulationszone möglich. Gleiches wird in vorteilhafter Weise bewirkt, wenn die zusätzlichen Bohrungen in der Brennersichel derart angeordnet sind, dass sie eine Eindüsung des Brennstoffes in Gegendrallrichtung zur Drallrichtung des Abgases in der Rezirkulationszone bewirken. It is also advantageous if the holes under one An angle of approx. 45 ° to the burner axis is arranged obliquely outwards are. Then there is a particularly intense mix of Fuel with the exhaust gas from the outer recirculation zone possible. The same is advantageously done if the additional holes arranged in the burner sickle are that they inject the fuel in the opposite direction to the swirl direction of the exhaust gas in the recirculation zone cause.

Kurze Beschreibung der ZeichnungBrief description of the drawing

In der Zeichnung ist ein Ausführungsbeispiel der Erfindung anhand eines Brenners der Doppelkegelbauart, der z.B. zum Betrieb einer Gasturbine eingesetzt wird, dargestellt.In the drawing is an embodiment of the invention using a double cone type burner, e.g. for operation a gas turbine is used.

Es zeigen:

Fig. 1
eine perspektivische Darstellung des Doppelkegelbrenners;
Fig. 2
einen Längsschnitt des Brenners mit der Brennkammer in schematischer Darstellung;
Fig. 3
einen Querschnitt des Brenners gemäss Fig. 1 entlang der Ebene III-III;
Fig. 4
einen Querschnitt des Brenners gemäss Fig. 1 entlang der Ebene IV-IV.
Show it:
Fig. 1
a perspective view of the double cone burner;
Fig. 2
a longitudinal section of the burner with the combustion chamber in a schematic representation;
Fig. 3
a cross section of the burner according to Figure 1 along the plane III-III.
Fig. 4
a cross section of the burner according to FIG. 1 along the plane IV-IV.

Es sind nur die für das Verständnis der Erfindung wesentlichen Elemente gezeigt. Die Strömungsrichtung der verschiedenen Medien ist mit Pfeilen bezeichnet.It is only essential for understanding the invention Elements shown. The flow direction of the different Media is marked with arrows.

Weg zur Ausführung der ErfindungWay of carrying out the invention

Nachfolgend wird die Erfindung anhand eines Ausführungsbeispieles und der Fig. 1 bis 4 näher erläutert.The invention is described below using an exemplary embodiment and FIGS. 1 to 4 explained in more detail.

Fig. 1 zeigt in perspektivischer Darstellung den erfindungsgemässen Brenner. Zum besseren Verständnis ist es vorteilhaft, wenn gleichzeitig zu Fig. 1 die Schnitte in den Fig. 2 bis 4 herangezogen werden.Fig. 1 shows a perspective view of the inventive Burner. For a better understanding, it is advantageous if at the same time as FIG. 1 the sections in FIG. 2 to 4 are used.

Der Brenner besteht aus zwei hohlen Teilkegelkörpern 1, 2, die versetzt zueinander aufeinander liegen. Die Versetzung der jeweiligen Mittelachsen 3, 4 der Teilkegelkörper 1, 2 zueinander schafft auf beiden Seiten in spiegelbildlicher Anordnung jeweils einen tangentialen Lufteintrittsschlitz 5, 6, durch welche die Verbrennungsluft 7 in den Innenraum 8 des Brenners gelangt. Die beiden Teilkegelkörper 1, 2 haben jeweils einen zylindrischen Anfangsteil 9, 10, die ebenfalls versetzt zueinander verlaufen, so dass auch in diesem Bereich die tangentiale Lufteintrittsschlitze 5, 6 vorhanden sind. In diesem zylindrischen Anfangsteil 9, 10 ist eine Düse 11 zur Zerstäubung des flüssigen Brennstoffes 12 untergebracht. Der Brenner kann auch ohne die zylindrischen Anfangsteile 9, 10 ausgeführt sein, so dass er rein kegelig ausgebildet ist. Dann ist die Brennstoffdüse 11 direkt in der Kegelspitze untergebracht. Die beiden Teilkegelkörper 1, 2 weisen je eine Brennstoffleitung 13, 14 auf, die mit Öffnungen 15 versehen sind, welche Brennstoffinjektoren darstellen. Durch die Brennstoffinjektoren 15 wird gasförmiger Brennstoff 16 der durch die tangentialen Lufteintrittsschlitze 5, 6 strömenden Verbrennungsluft 7 zugemischt.The burner consists of two hollow partial cone bodies 1, 2, which are offset from one another. The dislocation the respective central axes 3, 4 of the partial cone bodies 1, 2 to each other creates a mirror image arrangement on both sides each have a tangential air inlet slot 5, 6, through which the combustion air 7 in the interior 8 of the Brenners arrives. The two partial cone bodies 1, 2 each have a cylindrical starting part 9, 10, which also run offset to each other, so that in this area too the tangential air inlet slots 5, 6 are present. In this cylindrical starting part 9, 10 is a nozzle 11 for Atomization of the liquid fuel 12 housed. The Burner can also without the cylindrical starting parts 9, 10th be designed so that it is purely conical. Then the fuel nozzle 11 is accommodated directly in the cone tip. The two partial cone bodies 1, 2 each have one Fuel line 13, 14, which are provided with openings 15 which are fuel injectors. Through the Fuel injectors 15 becomes gaseous fuel 16 flowing through the tangential air inlet slots 5, 6 Combustion air 7 added.

Brennraumseitig 17 weist der Brenner eine als Verankerung für die Teilkegelkörper 1, 2 dienende Frontplatte 18 mit einer Anzahl Bohrungen 19 auf, durch welche Verdünnungs- bzw. Kühlluft 20 dem vorderen Teil des Brennraumes 17 bzw. dessen Wand zugeführt werden kann.Combustion chamber side 17 has a burner as an anchor for the partial cone body 1, 2 serving front plate 18 with a Number of holes 19 through which dilution or cooling air 20 the front part of the combustion chamber 17 or its wall can be supplied.

Wird zum Betrieb des Brenners flüssiger Brennstoff 12 verwendet, so strömt dieser durch die Düse 11 und wird in einem spitzen Winkel in den Brennerinnenraum 17 eingedüst, wobei sich ein homogener Brennstoffspray einstellt. Das kegelige Flüssigbrennstoffprofil 23 wird von einem tangential einströmenden rotierenden Verbrennungsluftstrom 7 umschlossen. In axialer Richtung wird die Konzentration des Flüssigbrennstoffes 12 fortlaufend durch die eingemischte Verbrennungsluft 7 verringert. Die optimale Brennstoffkonzentration über den Querschnitt wird erst im Bereich des Wirbelaufplatzens, d.h. im Bereich der inneren Rezirkulationszone 24 erreicht. Die Zündung erfolgt an der Spitze der inneren Rezirkulationszone 24. Diese wird im sogenannten Kopfstufenbetrieb (nicht dargestellt) mit Zusatzbrennstoff versorgt. Erst an dieser Stelle entsteht eine stabile Flammenfront 25. Die Flammenstabilisation ergibt sich durch Zunahme der Drallzahl in Strömungsrichtung entlang der Kegelachse. Ein Rückschlagen der Flamme in das Innere des Brenners tritt unter normalen Betriebsbedingungen nicht auf.If liquid fuel 12 is used to operate the burner, so it flows through the nozzle 11 and is in one injected acute angle into the burner interior 17, wherein a homogeneous fuel spray is established. The conical Liquid fuel profile 23 is of a tangentially flowing rotating combustion air flow 7 enclosed. In The concentration of the liquid fuel becomes axial 12 continuously through the mixed combustion air 7 reduced. The optimal fuel concentration over the Cross section is only in the area of the vertebral burst, i.e. reached in the area of the inner recirculation zone 24. The Ignition occurs at the top of the inner recirculation zone 24. This is in the so-called head stage operation (not shown) supplied with additional fuel. Only at this point creates a stable flame front 25. The flame stabilization results from an increase in the swirl number in the direction of flow along the cone axis. The flame strikes back enters the interior of the burner under normal operating conditions not on.

Wird gasförmiger Brennstoff 16 verbrannt, so geschieht die Gemischbildung mit der Verbrennungsluft 7 in den Lufteintrittsschlitzen 5, 6, also vor Eintritt in den Brennerinnenraum 8.If gaseous fuel 16 is burned, this happens Mixture formation with the combustion air 7 in the air inlet slots 5, 6, i.e. before entering the burner interior 8th.

Erfindungsgemäss sind im Bereich der Brennersichel 26 eine Reihe von Bohrungen 27 angeordnet, die der Zufuhr und Einmischung von zusätzlichem gasförmigem Brennstoff 16 in die äussere Rezirkulationszone 28 dienen. Der zusätzliche gasförmige Brennstoff 16 kann im Extremfall auch nur über eine einzige in der Brennersichel 26 angeordnete Bohrung 27 in die äussere Rezirkulationszone 28 eingebracht werden.According to the invention in the area of the burner sickle 26 Row of holes 27 arranged for the supply and interference of additional gaseous fuel 16 to the outside Recirculation zone 28 serve. The additional gaseous In extreme cases, fuel 16 can only have one in the burner sickle 26 arranged bore 27 in the outer Recirculation zone 28 are introduced.

Wie aus Fig. 2 hervorgeht, befindet sich diese äussere Rezirkulationszone 28 im äusseren Bereich des Brennraumes 17, nahe der Wand der Brennkammer 21.As can be seen from Fig. 2, this outer recirculation zone is located 28 in the outer area of the combustion chamber 17, close the wall of the combustion chamber 21.

Die Bohrungen 27 können in verschiedener Weise in der Brennersichel 26 angeordnet sein, beispielsweise parallel zur Brennerachse 22. In anderen Ausführungsbeispielen können sie auch unter einem Winkel zur Brennerachse 22 von etwa 45° schräg nach aussen angeordnet sein , so dass der zusätzliche gasförmige Brennstoff 16 in Richtung Brennkammerwand eingedüst wird. Besonders vorteilhaft ist es, wenn die Bohrungen 27 so angeordnet sind, dass der zusätzliche gasförmige Brennstoff 16 in Gegendrallrichtung zur Rezirkulationsströmung eingebracht wird, weil dann eine besonders intensive Mischung des Zusatzbrennstoffes mit dem rezirkulierendem Abgas erfolgt und die darauf beruhende Flammenstabilisierung besonders hoch ist.The holes 27 can be in different ways in the burner sickle 26 may be arranged, for example parallel to Burner axis 22. In other exemplary embodiments, they can also at an angle to the burner axis 22 of approximately 45 ° be arranged obliquely outwards, so that the additional gaseous fuel 16 injected towards the combustion chamber wall becomes. It is particularly advantageous if the bores 27 are arranged so that the additional gaseous fuel 16 in the counter-swirl direction to the recirculation flow is introduced because then a particularly intensive mixture of the additional fuel with the recirculating exhaust gas and the resulting flame stabilization is particularly high is.

Der Brenner ist erfindungsgemäss so zu betreiben, dass nur etwa 3 bis 8% des gesamten gasförmigen Brennstoffes durch die Öffnungen 27 in die äussere Rezirkulationszone 28 gelangen. Da an dieser Stelle bereits die Kühlluft 20 beigemischt ist und die rezirkulierenden Abgase bereits einen Teil ihrer fühlbaren Wärme an die Frontplatte 18 abgegeben haben, bewirkt diese zusätzliche Brennstoffzugabe keine nennenswerte Erhöhung der NOx-Emissionen. Dies trifft insbesondere dann zu, wenn die Eindüsungen genügend klein sind, um eine Stabilisierung an den Eintrittsstrahlen zu vermeiden. Nach der Brennstoffeinmischung erfolgt nach einer gewissen Zündverzugszeit Selbstzündung und zwar kurz vor oder direkt an der äusseren Scherschicht des austretenden Brennstoff/Luft-Gemisches.According to the invention, the burner is to be operated such that only about 3 to 8% of the total gaseous fuel through the Open openings 27 into the outer recirculation zone 28. Since the cooling air 20 is already mixed in at this point and the recirculating exhaust gases are already part of theirs have given sensible heat to the front panel 18 this additional fuel addition is not worth mentioning Increase in NOx emissions. This is especially true when the injections are small enough to stabilize to avoid at the entrance beams. After Fuel is mixed in after a certain ignition delay Auto ignition and just before or directly on the outer shear layer of the emerging fuel / air mixture.

Durch die Erfindung wird eine externe Zusatzstabilisierung (durch Minipiloten) realisiert, die u.a. zu einer Erweiterung des Betriebsbereiches des Brenners und zu einer erhöhten Flammenstabilität führt.The invention provides an external additional stabilization (by mini pilots), which among other things to an extension the operating range of the burner and to an increased Flame stability leads.

Messungen an einem perfekt vorgemischten Versuchsbrenner haben gezeigt, dass eine Verschiebung der mageren Löschgrenze um ca. 100K zu kleineren Temperaturen hin mit einer sehr geringen Zunahme der Schadstoffemissionen (zusätzlich ca. 1,5 vppmd 15%O2, d.h. Konzentration des NOx im trockenen Abgas) möglich ist.Measurements on a perfectly premixed test burner have shown that a shift of the lean extinguishing limit by approx. 100K to lower temperatures with a very small increase in pollutant emissions (additionally approx. 1.5 vppmd 15% O 2 , ie concentration of NOx in the dry exhaust gas ) is possible.

In Fig. 4 ist in einem Querschnitt eine konkrete Ausführung der Erfindung dargestellt. Der Querschnitt zeigt den Bereich der Brenneraustrittssichel 26. In der Sichel 26 sind an 14 Positionen am Umfang mit einer Winkelteilung von etwa 10° Bohrungen 26 mit einem Durchmesser von 0,8mm angeordnet. Die Anzahl und Grösse der Bohrungen 26 wurde so gewählt, dass ca. 3% des gesamten Brennstoffmassenstromes dort austreten und in die in Fig. 4 nicht dargestellte äussere Rezirkulationszone 28 eingemischt werden.4 is a concrete embodiment in a cross section presented the invention. The cross section shows the area the burner exit sickle 26. In the sickle 26 are 14 Positions on the circumference with an angular division of approximately 10 ° Bores 26 arranged with a diameter of 0.8 mm. The The number and size of the bores 26 was chosen so that approx. 3% of the total fuel mass flow there and in the outer recirculation zone, not shown in Fig. 4 28 can be mixed.

Die erfindungsgemässe Lösung kann ebenso auch für Brenner verwendet werden, die aus mehr als zwei Teilkegelkörpern bestehen, z.B. für sogenannte Vierschlitzbrenner. Die Bohrungen 27 können ausserdem sowohl in ihrer Anzahl als auch in ihrer Position in der Brennersichel 26 variieren. Es ist lediglich darauf zu achten, dass der zusätzliche Brennstoffmassenstrom, der in die äussere Rezirkulationszone eingemischt wird, nicht mehr als ca. 8% des Gesamtbrennstoffes ausmacht.The inventive Solution can also be used for burners, which consist of more than two partial cone bodies, e.g. for so-called Four slot burner. The holes 27 can also both in their number and in their position in the Burner sickle 26 vary. You just have to take care that the additional fuel mass flow that goes into the outer recirculation zone is mixed in, no more than accounts for approx. 8% of the total fuel.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

11
TeilkegelkörperPartial conical bodies
22
TeilkegelkörperPartial conical bodies
33
Mittelachse von Pos. 1Central axis of item 1
44
Mittelachse von Pos. 2Central axis of item 2
55
tangentialer Lufteintrittsschlitztangential air inlet slot
66
tangentialer Lufteintrittsschlitztangential air inlet slot
77
Verbrennungsluftcombustion air
88th
BrennerinnenraumBurner interior
99
zylindrischer Anfangsteil von Pos. 1cylindrical starting part of item 1
1010
zylindrischer Anfangsteil von Pos. 2cylindrical starting part of item 2
1111
Brennstoffdüsefuel nozzle
1212
flüssiger Brennstoffliquid fuel
1313
Brennstoffleitung für Pos. 16Fuel line for item 16
1414
Brennstoffleitung für Pos. 16Fuel line for item 16
1515
Brennstoffinjektor für Pos. 16Fuel injector for item 16
1616
gasförmiger Brennstoffgaseous fuel
1717
Brennraumcombustion chamber
1818
Frontplattefront panel
1919
Bohrung für Pos. 20Hole for item 20
2020
Verdünnungs- bzw. KühlluftDilution or cooling air
2121
Brennkammercombustion chamber
2222
BrennerachseBrenner
2323
FlüssigbrennstoffprofilLiquid fuel profile
2424
innere Rezirkulationszoneinner recirculation zone
2525
Flammenfrontflame front
2626
Brennersichelburner sickle
2727
Bohrungdrilling
2828
äussere Rezirkulationszoneouter recirculation zone

Claims (5)

  1. Burner for burning liquid (12) and gaseous fuels (16), comprising at least two hollow sectional cone bodies (1, 2) complementing one another to form one body, having tangential air-inlet slots (5, 6) and feeds (13, 14) for gaseous fuels (16), in which burner the centre axes (3, 4) of the hollow sectional cone bodies (1, 2) have a conicity widening in the direction of flow and run offset from one another in the longitudinal direction, a fuel nozzle (11) for the liquid fuel (12) being placed at the burner head in the conical interior space (8) formed by the sectional cone bodies (1, 2), and the feeds (13, 14) for the gaseous fuel (16) being provided with fuel injectors (15), and air-inlet slots (5, 6) being closed off on the combustion-chamber side by a burner sickle (26), characterized in that at least one bore (27) is arranged in the burner sickle (26), which bore (27) is provided for the feed of gaseous fuel (16).
  2. Burner according to Claim 1, characterized in that the at least one bore (27) is arranged parallel to the burner axis (22).
  3. Burner according to Claim 1, characterized in that the at least one bore (27) is arranged so as to slope outwards at an angle to the burner axis (22), preferably at an angle of 45°.
  4. Method of operating a burner according to one of Claims 1 to 3, a conical liquid fuel column (23) being formed in the interior space (8) of the burner, which liquid fuel column (23) spreads in the direction of flow, does not wet the walls of the interior space (8), is enclosed by a rotating combustion-air flow (7) flowing tangentially into the burner and/or is fed to the combustion-air flow (7) before it flows into the interior space (8) of the burner, the ignition of the mixture takes place only at the outlet of the burner, and the flame is stabilized in the region of the burner orifice by an inner recirculation zone (24), characterized in that 3 to 8 % of the total mass fuel flow is mixed into an outer recirculation zone (28).
  5. Method according to Claim 4, characterized in that the fuel (16) mixed into an outer recirculation zone (28) is injected in the opposite direction to the swirl direction of the recirculation flow.
EP97810385A 1996-06-29 1997-06-18 Premix burner and method of operating the burner Expired - Lifetime EP0816759B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19626240A DE19626240A1 (en) 1996-06-29 1996-06-29 Premix burner and method of operating the burner
DE19626240 1996-06-29
US08/865,102 US5782627A (en) 1996-06-29 1997-05-29 Premix burner and method of operating the burner

Publications (3)

Publication Number Publication Date
EP0816759A2 EP0816759A2 (en) 1998-01-07
EP0816759A3 EP0816759A3 (en) 1998-11-11
EP0816759B1 true EP0816759B1 (en) 2003-01-08

Family

ID=26027058

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Application Number Title Priority Date Filing Date
EP97810385A Expired - Lifetime EP0816759B1 (en) 1996-06-29 1997-06-18 Premix burner and method of operating the burner

Country Status (5)

Country Link
US (1) US5782627A (en)
EP (1) EP0816759B1 (en)
JP (1) JPH1061916A (en)
CN (1) CN1170844A (en)
DE (1) DE19626240A1 (en)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19839085C2 (en) 1998-08-27 2000-06-08 Siemens Ag Burner arrangement with primary and secondary pilot burner
US6672862B2 (en) 2000-03-24 2004-01-06 North American Manufacturing Company Premix burner with integral mixers and supplementary burner system
GB2362847A (en) * 2000-06-02 2001-12-05 Hamworthy Combustion Eng Ltd Fuel burner nozzle
US6360776B1 (en) * 2000-11-01 2002-03-26 Rolls-Royce Corporation Apparatus for premixing in a gas turbine engine
WO2003088508A2 (en) * 2002-04-09 2003-10-23 Sapias, Inc. Asset management platform
US6623267B1 (en) 2002-12-31 2003-09-23 Tibbs M. Golladay, Jr. Industrial burner
US20040202977A1 (en) * 2003-04-08 2004-10-14 Ken Walkup Low NOx burner
JP4913746B2 (en) * 2004-11-30 2012-04-11 アルストム テクノロジー リミテッド Method and apparatus for burning hydrogen in a premix burner
EP1828684A1 (en) * 2004-12-23 2007-09-05 Alstom Technology Ltd Premix burner comprising a mixing section
DE102006005386B4 (en) * 2006-02-03 2009-04-09 Uhde Gmbh Gas burner with optimized nozzle arrangement
US20090301054A1 (en) * 2008-06-04 2009-12-10 Simpson Stanley F Turbine system having exhaust gas recirculation and reheat
CN102128453A (en) * 2011-01-28 2011-07-20 岳阳科德科技有限责任公司 Pre-combustion burner
US8984887B2 (en) * 2011-09-25 2015-03-24 General Electric Company Combustor and method for supplying fuel to a combustor
CZ305842B6 (en) * 2014-06-13 2016-04-06 Vysoké Učení Technické V Brně Burner head of injector-type stabilization burner
US10739006B2 (en) * 2017-03-15 2020-08-11 General Electric Company Fuel nozzle for a gas turbine engine
US10982846B2 (en) * 2017-06-14 2021-04-20 Webster Combustion Technology Llc Vortex recirculating combustion burner head

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2302483A1 (en) * 1975-02-28 1976-09-24 Heurtey Efflutherm Evapn. and thermal oxidn. of liq. effluents - by burning with flame in combustion chamber
DE3446788A1 (en) * 1984-12-21 1986-07-03 L. & C. Steinmüller GmbH, 5270 Gummersbach Flame vaporising-burner with precombustion chamber
DE3662462D1 (en) * 1985-07-30 1989-04-20 Bbc Brown Boveri & Cie Dual combustor
CH674561A5 (en) * 1987-12-21 1990-06-15 Bbc Brown Boveri & Cie
US4863371A (en) * 1988-06-03 1989-09-05 Union Carbide Corporation Low NOx high efficiency combustion process
JP2713627B2 (en) * 1989-03-20 1998-02-16 株式会社日立製作所 Gas turbine combustor, gas turbine equipment including the same, and combustion method
CH682952A5 (en) * 1991-03-12 1993-12-15 Asea Brown Boveri Burner for a premixing combustion of a liquid and / or gaseous fuel.
CH684962A5 (en) * 1991-07-03 1995-02-15 Asea Brown Boveri Burner for operating an internal combustion engine, a combustor of a gas turbine group or a firing.
DE59104727D1 (en) * 1991-12-23 1995-03-30 Asea Brown Boveri Device for mixing two gaseous components and burner in which this device is used.
US5307634A (en) * 1992-02-26 1994-05-03 United Technologies Corporation Premix gas nozzle
DE4304213A1 (en) * 1993-02-12 1994-08-18 Abb Research Ltd Burner for operating an internal combustion engine, a combustion chamber of a gas turbine group or a combustion system
DE4411623A1 (en) * 1994-04-02 1995-10-05 Abb Management Ag Premix burner
DE4416650A1 (en) * 1994-05-11 1995-11-16 Abb Management Ag Combustion process for atmospheric combustion plants

Also Published As

Publication number Publication date
EP0816759A3 (en) 1998-11-11
EP0816759A2 (en) 1998-01-07
DE19626240A1 (en) 1998-01-02
US5782627A (en) 1998-07-21
CN1170844A (en) 1998-01-21
JPH1061916A (en) 1998-03-06

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