[go: up one dir, main page]

EP1087177B1 - Brenner und ofen für verbrennung und flammhydrolyse und verbrennungsverfahren - Google Patents

Brenner und ofen für verbrennung und flammhydrolyse und verbrennungsverfahren Download PDF

Info

Publication number
EP1087177B1
EP1087177B1 EP99912120A EP99912120A EP1087177B1 EP 1087177 B1 EP1087177 B1 EP 1087177B1 EP 99912120 A EP99912120 A EP 99912120A EP 99912120 A EP99912120 A EP 99912120A EP 1087177 B1 EP1087177 B1 EP 1087177B1
Authority
EP
European Patent Office
Prior art keywords
combustion
burner
tip
tube
outer tube
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
EP99912120A
Other languages
English (en)
French (fr)
Other versions
EP1087177A1 (de
EP1087177A4 (de
Inventor
Shinichi Shin-Etsu Chemical Co. Ltd. Kurotani
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.)
Shin Etsu Chemical Co Ltd
Original Assignee
Shin Etsu Chemical Co Ltd
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
Application filed by Shin Etsu Chemical Co Ltd filed Critical Shin Etsu Chemical Co Ltd
Publication of EP1087177A1 publication Critical patent/EP1087177A1/de
Publication of EP1087177A4 publication Critical patent/EP1087177A4/de
Application granted granted Critical
Publication of EP1087177B1 publication Critical patent/EP1087177B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D11/00—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
    • F23D11/36—Details, e.g. burner cooling means, noise reduction means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D11/00—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
    • F23D11/10—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space the spraying being induced by a gaseous medium, e.g. water vapour
    • F23D11/106—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space the spraying being induced by a gaseous medium, e.g. water vapour medium and fuel meeting at the burner outlet
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
    • F23D2900/00016—Preventing or reducing deposit build-up on burner parts, e.g. from carbon

Definitions

  • the present invention relates to a burner which, when used to atomize and burn or flame-hydrolyze a liquid containing a chemical element that forms a solid oxide by combustion or flame hydrolysis, discourages the deposition and buildup of solid oxide on the burner proper, in the burner vicinity and at the interior of the furnace in which combustion takes place, by virtue of which the burner is capable of stable and continuous long-term operation and can efficiently burn or flame-hydrolyze the liquid.
  • the invention also relates to a combustion furnace equipped with this burner, and to a process for burning such a liquid using the same burner.
  • Known processes for burning combustible liquids include methods in which the combustible liquid is either rendered by a variety of techniques into a mist-like mixture of liquid droplets and gas or vaporized, then is delivered to an incinerator and burned; and methods in which the combustible liquid is mixed with a solid such as sludge, sand or assorted debris, and burned.
  • the combustion method involving vaporization with a vaporizing burner is applicable to fuels having a boiling point lower than the thermal decomposition temperature, such as distillate oils (e.g., gasoline, kerosene, gas oil).
  • distillate oils e.g., gasoline, kerosene, gas oil
  • this method gives rise to carbon deposition and other undesirable effects on account of thermal decomposition.
  • Combustion involving mixture of the combustible liquid with a solid material also has numerous limitations, including the requirement that the liquid and the solid material form a non-reactive, chemically stable combination.
  • the combustible liquid to be burned contains a chemical element from group 1A other than hydrogen, group 2A, group 3B, group 4B, group 5B, group 6B, group 7B, group 8, group 1B, group 2B, group 3A, group 4A other than carbon, group 5A other than nitrogen, or group 6A other than oxygen and sulfur (which elements are collectively referred to hereinafter as the "S element") of the CAS version of the periodic table of the elements (see F.
  • S liquid combustible liquid containing the above-described S element-containing compound
  • undesirable effects arise due to the formation of the S element oxide. These effects are especially striking when the concentration of S element-containing compound is high.
  • Measures that are used to avoid such effects include diluting the S liquid so as to lower the concentration of S element oxide in the combustion gas, and changing the type of burner or the atomization technique.
  • WO 97/22553 ( EP 0 978 487 A ) describes a method and apparatus for making fused silica glass by flame hydrolysis.
  • the apparatus includes a burner having a series of concentric channels surrounding an atomizer through which a liquid silicon-containing compound is introduced directly into a flame.
  • combustion technology designed specifically for compounds that form solids when burned.
  • special material gases such as the silanes, arsines and phosphines in waste gases discharged from semiconductor fabrication equipment, and have a construction that prevents the deposition of combustion products in the vicinity of the burner, are known to the art (see JP-A 59-279014 , JP-B 62-134414 and JP-B 1-95214 ) and have been furnished for practical use.
  • all this technology is targeted at the treatment of substances which are gases, and so the following drawbacks are encountered when these known processes are used to burn S liquids.
  • combustion furnaces may be used to burn S element-containing liquids, including stoker furnaces, fixed-bed furnaces, rotary-hearth furnaces, multiple-hearth furnaces, rotary kilns, fluidized-bed furnaces and vertical cylindrical furnaces.
  • the appropriate type of furnace is selected according to the presence or absence of solids and gases which burn at the same time, as well as the properties and amounts thereof.
  • the method hitherto used has involved temporarily stopping combustion to periodically clean off the S element oxide that has deposited, built up and solidified within the furnace and remove the oxide from the furnace, then re-igniting the furnace and continuing combustion.
  • a liquid containing a silicon compound (referred to hereinafter as a "silicon liquid”) is burned in a vertical cylindrical furnace equipped with an external-mixing burner comprising a central tube having a pressure atomizing configuration, an outer tube which concentrically surrounds the central tube and supplies air or oxygen, and a flame holder situated in front of the central tube (which burner is referred to hereinafter as a "double-tube burner”).
  • the silicon dioxide powder begins to deposit onto the surface of the flame holder and the inside walls of the furnace about 1 to 2 hours after the start of combustion. The thickness of the powder deposits gradually increases and the powder sinters, forming a hard, porous vitreous substance.
  • the vitreous substance stops good atomization from occurring, reduces the volume of the combustion chamber and changes the shape of the chamber, resulting in a loss in flame stability. In the worst case, this may lead to obstruction of the burner discharge orifices or the combustion chamber and flame failure.
  • Reducing the frequency of such cleaning calls not only for a change in the combustion conditions, such as the ratio of combustion-supporting gases (e.g., air, oxygen) and the feed rate of silicon liquid, but also for lowering the concentration of the silicon-containing compound within the silicon liquid by using a liquid capable of dilution or admixture with the silicon liquid (e.g., toluene, xylene, kerosene) to dilute or mix with the silicon liquid or, alternatively, for lowering the concentration of silicon-containing compound within the substance being burned by burning at the same time a solid material such as sludge, assorted debris or sawdust.
  • a sufficient concentration lowering effect requires, as noted above, that the concentration of the silicon-containing compound be set very low. The result is an increase in dilution-related work and in the amount of material fed to the process, and a decline in the capacity to burn silicon liquid. Clearly, this is not an economically desirable approach.
  • Another object of the invention is to provide a combustion furnace equipped with the same burner and a process for burning the foregoing liquid using the same burner.
  • the invention provides the burner, combustion furnace and combustion processes described below.
  • the chemical element that forms a solid oxide by combustion or flame hydrolysis is silicon
  • the velocity of liquid emission from the central tube is 5 to 250 m/s
  • the velocity of gas emission from the first outer tube is 1 to 250 m/s
  • the velocity of gas emission from the second outer tube is 1 to 250 m/s
  • a burner tile is provided outside of the second outer tube
  • the amount of combustion-supporting gases relative to the substance being burned is 0.5 to 5.0 times the stoichiometric amount.
  • a combustion furnace is characterized by comprising the above-described burner, a mechanism which holds the surface temperature on an inside wall of the furnace or the surface temperature of solid oxide deposits on the furnace inside wall lower than the melting point or sticking temperature of the solid oxide, and/or a mechanism which can remove solid oxide deposits from the inside wall of the furnace.
  • the chemical element that forms a solid oxide by combustion or flame hydrolysis is silicon;
  • the burner is configured such that the central tube has an atomizing mechanism at the tip thereof, each outer tube concentrically surrounding the central tube has a tip that is either stepped back from the tip of the central tube or projects forward therefrom and, if necessary, a flame holder is disposed in front of the central tube; and the velocity of liquid emission from the central tube is 5 to 250 m/s, the velocity of gas emission from the first and second outer tubes is 1 to 250 m/s, and the amount of combustion-supporting gases relative to the substance being burned is 0.5 to 5.0 times the stoichiometric amount.
  • the combustion furnace additionally has a mechanism that holds the surface temperature on the inside wall of the furnace at from 200 to 1,000°C and/or a mechanism that can remove solid oxide deposits from the inside wall of the furnace.
  • a combustion process for atomizing and burning or flame hydrolysing a combustible liquid containing a chemical element that forms a solid oxide on such combustion or flame hydrolysis using a burner arrangement having a burner with a circularly-concentric multi-tube construction of three or more tubes including a central tube which is tapered towards the tip and having an atomising mechanism at the tip thereof; a first outer tube disposed concentrically outside the central tube, and a second outer tube disposed concentrically outside the first outer tube; wherein the tip portion of each of the first and second outer tubes is shaped such as to taper towards the tip; and wherein
  • a combution process according to the first embodiment further comprising carrying out treatment to hold the surface temperature at an inside wall of the combustion furnace below the melting point or sticking temperature of the solid oxide and/or carrying out treatment to remove solid oxide deposits from the inside wall of the furnace.
  • the chemical element that forms a solid oxide by combustion or flame hydrolysis is silicon, and the surface temperature on the inside wall of the furnace or the surface temperature of solid oxide deposits on the furnace inside wall is held at from 200 to 1,000°C.
  • the burner of the invention has a flame-generating burner main body with a multi-tube construction.
  • the flame formed by atomization of a liquid containing the above-described S element-containing compound is covered from the outside with a combustion-supporting gas such as air or oxygen or with a non-combustible gas such as nitrogen containing the combustion-supporting gases so as to keep combustion gases present in the furnace from passing through and mixing with the flame.
  • a combustion-supporting gas such as air or oxygen
  • a non-combustible gas such as nitrogen containing the combustion-supporting gases
  • the burner according to the above preferred embodiment atomizes and burns as fine droplets the S liquid emitted from the central tube with a combustion-supporting gas such as air or oxygen emitted from the first outer tube.
  • a combustion-supporting gas such as air or oxygen, or a non-combustible gas containing the combustion-supporting gas, that has been emitted from the second or a subsequent outer tube.
  • the flame is covered by the combustion-supporting gas such as air or oxygen, or the non-combustible gas such as nitrogen, that has been emitted from the gap between the second or subsequent outer tube and the burner tile, the flame is shielded from circulation and mixture with combustion gases present within the combustion furnace.
  • the combustion-supporting gas such as air or oxygen
  • the non-combustible gas such as nitrogen
  • the vicinity of the central tube tip is covered with a stream of air, oxygen, nitrogen or the like emitted from a second or subsequent outer tube, the small amount of S element oxide that has been entrained by the internally circulating flow never reaches the vicinity of the atomizing orifice on the central tube, making it possible to prevent deposition of the S element oxide.
  • the inventive burner thus resists the deposition and build up of S element oxides on the burner itself and in its vicinity, enabling stable and continuous operation for an extended period of time, and in turn making it possible to efficiently burn liquids such as waste products containing S element-bearing compounds.
  • the concentration of S element oxides in gases near the burner itself and near the furnace walls in the burner vicinity is minimized, effectively suppressing deposition on solid wall surfaces.
  • the small amount of S element oxide entrained by the internally circulating flow lightly deposits on the surface of the flame holder and never reaches the vicinity of the atomizing orifice at the tip portion of the central tube positioned behind the flame holder, and so no change occurs in the atomizing state, making it possible to maintain good atomization.
  • the S element oxide which has deposited on the surface of the flame holder is cooled by the combustion-supporting gas such as air or oxygen or the non-combustible gas such as nitrogen that is emitted from the first outer tube, it does not reach a temperature at which melting and solidification take place. Hence, the deposits thicken while remaining in the form of a powder, and stable combustion is not hindered by the flaking off of vitrified deposits.
  • the combustion-supporting gas such as air or oxygen or the non-combustible gas such as nitrogen that is emitted from the first outer tube
  • the combustion furnace according to the above-described preferred embodiment has a mechanism which holds the temperature of the furnace inside walls lower than the temperature at which the S element oxide fuses or sticks, preventing the melting and solidification of any S element oxide powder formed by combustion that has deposited on the inside walls, and keeping such deposits in an easy-to-remove state.
  • the above furnace also has a mechanism for removing powder deposits from the wall surface and enabling such deposits to be taken out of the combustion system. This makes it possible to prevent the buildup of S element oxide powder on the inside walls of the furnace, so that stable and continuous combustion can be achieved.
  • a specific example of an effective mechanism for holding the temperature on the inside walls of the furnace within a required range is a method that involves spraying water within the combustion chamber.
  • Other suitable methods that may be used for this purpose include cooling the walls by means of coolant circulation in a water-cooled wall construction, for example; and supplying cooling air.
  • Effective methods for removing powder from the inside walls of the furnace include the installation of a movable scraper or soot blowers within the furnace.
  • the combustion furnace of the invention discourages the deposition and buildup of solid oxides on or in the vicinity of the burner, is able to maintain solid oxides which deposit on the furnace inside walls in an easy-to-remove state that enables such deposits to be taken out of the system, and can efficiently burn liquids such as S element-containing waste products.
  • every type of burner and combustion furnace that has been used to date for burning combustible liquids has been designed and developed for fuels, such as fuel oils (e.g., kerosene, heavy oils), which generate little or no solids from combustion, other than soot from incomplete combustion and products originating from trace amounts of inadvertent impurities in the fuel.
  • fuel oils e.g., kerosene, heavy oils
  • prior-art burners and combustion furnaces are not adapted for burning substances such as S liquids that generate a large amount (depending on the composition of the S liquid, at least 50% by weight of the material burned) of solids by combustion or flame hydrolysis.
  • silicon dioxide formed in the flame is entrained by the externally recirculating flow that arises near the flame and the internally recirculating flow that arises at the flame interior, and readily approaches the solid wall that extends from the vicinity of the burner discharge orifices to the furnace interior. Because the silicon dioxide formed by combustion at this time has strong cohesive and adhesive forces, it readily deposits and builds up on solid wall surfaces. In addition, the burner vicinity and the furnace walls are exposed to elevated temperatures due to the influence of radiant heat, for example, causing the silicon dioxide powder to sinter, melt and solidify, often forming hard, porous, and strongly adhering vitreous deposits.
  • the solid oxide does not readily deposit and build up on the burner itself, in the burner vicinity or inside the combustion furnace, thereby enabling stable and continuous long-term operation and making it possible to efficiently burn combustible liquids such as waste products containing silicon-bearing compounds.
  • the invention provides a burner for the combustion of silicon-containing compounds that atomizes as liquid droplets, then burns or flame-hydrolyzes, a silicon-bearing compound-containing combustible liquid within a combustion furnace.
  • the flame-generating burner main body has a circularly concentric multi-tube construction of at least three tubes comprising a central tube which emits a combustible liquid containing a silicon-bearing compound, and two or more outer tubes disposed concentrically outside the central tube which emit a combustion-supporting gas and/or a non-combustible gas.
  • the burner is constructed such that the flame discharged from the central tube is covered by the gas jets emitted from the outer tubes, thereby restricting circulation and admixture of the flame with combustion gases within the furnace.
  • Combustible liquids that may be furnished for combustion herein include organic silicon compounds such as liquid silanes (e.g., tetramethoxysilane), siloxanes (e.g., hexamethyldisiloxane) or silazanes (e.g., hexamethyldisilazane), and silicone varnishes containing these liquid organic silicon compounds.
  • organic silicon compounds such as liquid silanes (e.g., tetramethoxysilane), siloxanes (e.g., hexamethyldisiloxane) or silazanes (e.g., hexamethyldisilazane), and silicone varnishes containing these liquid organic silicon compounds.
  • Specific examples of liquids that may be furnished for combustion include silicone production equipment wash fluids, and distillation fractions and residues from silicone production.
  • Suitable examples of the combustion-supporting gas emitted from the outer tubes include air and oxygen.
  • dry air or oxygen is preferably emitted from the first outer tube concentrically surrounding the central tube which emits the above combustible liquid. Dry air or oxygen may also be emitted from the second outer tube surrounding the first outer tube, although the emission of ordinary air that has not been subjected to a drying operation suffices.
  • a burner tile may be disposed at a predetermined interval outside of the outer tubes so as to surround the outermost tube.
  • a combustion-supporting gas such as air or oxygen may be emitted between the outermost tube and the burner tile.
  • a non-combustible gas such as nitrogen may be emitted together with, or even in place of, the combustion-supporting gas.
  • the first outer tube preferably emits a combustion-supporting gas such as air or oxygen
  • the second outer tube preferably emits a combustion-supporting gas or a non-combustible gas containing a combustion-supporting gas, although in some cases it may emit only a non-combustible gas.
  • both the first and second outer tubes it is preferable for both the first and second outer tubes to emit a combustion-supporting gas or a non-combustible gas containing a combustion-supporting gas.
  • the velocity of gas emission from the first and second outer tubes is preferably from 1 to 250 m/s.
  • the velocity of gas emission from between the outermost tube and the burner tile is preferably from 5 to 100 m/s when air is used as the gas.
  • Any suitable technique may be used for atomizing the liquid in the central tube of the multi-tube burner, provided it has a mechanism for mixing the liquid with a gas to obtain a mist-like mixture of liquid droplets and gas.
  • atomizing techniques include mechanical atomization, rotary atomization and twin-fluid atomization.
  • a silicon liquid is emitted from the central tube in the multi-tube burner, and the flame generated at this time must be covered by the jets of gas discharged from the outer tubes.
  • the silicon liquid is discharged from somewhere other than the central tube, such as from the first or second outer tube, the operative principle does not apply, and so the silicon dioxide formed by combustion readily deposits in the vicinity of the discharge orifices, making the burner unfit for practical use.
  • FIGS. 1 to 3 illustrate a specific embodiment of a burner according to the present invention in which the central tube for discharging a liquid is of an external-mixing twin-fluid atomizing configuration.
  • the burner has a main body comprising a liquid-emitting central tube 1 in combination with first and second combustion-supporting gas and/or non-combustible gas-emitting outer tubes 2 and 3 disposed with circular concentricity outside of the central tube 1.
  • the tip of the central tube 1 projects out beyond the tip of the inside outer tube 2, and the tip of the inside outer tube 2 projects out beyond the tip of the outside outer tube 3.
  • the combustible liquid, the combustion-supporting gas such as air or oxygen, and/or the non-combustible gas such as nitrogen are each supplied to central tube 1 and outer tubes 2 and 3 from fluid feed ports 5.
  • the burner has a burner tile 4 disposed such as to surround the outside of the outermost tube 3.
  • the tip of the burner main body is situated short of the face of the burner tile on the furnace interior side thereof.
  • air or the like is fed from an air inlet 8 to a flow passage 7 (between the burner tile 4 and the second outer tube 3) having a windbox 6.
  • FIG. 3 which is a schematic partially cutaway view showing the tip portion of the multi-tube arrangement in the burner shown in FIG. 1 , a combustible liquid passage 9 is formed within the central tube 1, and gas passages 10 and 11 are formed respectively in outer tubes 2 and 3.
  • the inventive burner depicted in FIGS. 1 to 3 has the following construction.
  • the flow rate of combustion-supporting gas and non-combustible gas for covering the flame is preferable for the flow rate of combustion-supporting gas and non-combustible gas for covering the flame to be within a suitable range which is at least sufficient to shield the flame from combustion gases present within the combustion furnace, yet is not so excessive as to hinder combustion.
  • a suitable range which is at least sufficient to shield the flame from combustion gases present within the combustion furnace, yet is not so excessive as to hinder combustion.
  • the velocity of the fluid emitted from each tube in the multi-tube arrangement is regulated within a range in velocity which is at least sufficient to maintain good atomization yet not so excessive as to hinder combustion.
  • the velocity of liquid emission from the central tube is preferably set at from 5 to 250 m/s
  • the velocity of gas emission from the first outer tube is preferably set at from 1 to 250 m/s
  • the velocity of gas emission from the second outer tube is preferably set at from 1 to 250 m/s
  • the velocity of gas emission from between the outermost tube and the burner tile when air is used as the gas is preferably set at from 5 to 100 m/s.
  • the amount of combustion-supporting gas supplied between the outer tubes and the burner tile, relative to the substance being burned that is emitted from the central tube is preferably 0.5 to 5.0 times the stoichiometric amount.
  • the liquid is atomized by being emitted at the above-indicated velocity and a temperature and pressure below the boiling point and by emission of the combustion-supporting gas and/or non-combustible gas from the first outer tube at the above-indicated velocity and a temperature of 0 to 30°C.
  • the resulting atomized mixture is burned, and the flame thus generated is covered, with the combustion-supporting gas and/or non-combustible gas emitted from the second and subsequent outer tubes and also from between the burner tile and the outermost tube.
  • the temperature of the combustion-supporting gas and/or non-combustible gas emitted from the second and subsequent outer tubes and from between the burner tile and the outermost tube is preferably from 0 to 30°C.
  • a plurality of burners having the construction of the invention may be installed at the interior of a single burner tile. Moreover, the burner tile may be preheated to improve the fluidity of the combustible liquid and of the combustion-supporting gas and non-combustible gas supplied to the burner, as well as for other reasons, such as controlling combustion.
  • the combustion furnace of the invention has a cooling mechanism for maintaining the temperature at the inside walls thereof within a required range, and also has a mechanism for removing and eliminating solids that have deposited on the inside walls.
  • This arrangement has a two-fold purpose.
  • the oxide that has formed from combustion at the above-described burner has deposited as a powder on the inside walls of the furnace, the oxide powder is kept at a temperature lower than its sintering temperature or melting point so as to maintain the powder in an easy-to-remove state.
  • periodic operation of the removal mechanism serves to remove such deposits from the system while still in the form of a powder.
  • One effective mechanism for keeping the temperature of the furnace inside wall within the required range is to spray the inside of the furnace with water.
  • Other methods that may be used to achieve the same end include the use of a furnace wall having a coolant-circulating construction such as a water-cooled wall, and methods involving the supply of cold air.
  • One effective deposit-removing mechanism is a soot blower.
  • Other methods that may be used include installing a movable scraper within the furnace, and passing spheres made of a heat-resistant material such as iron or ceramic along the inside surface of the furnace walls.
  • the surface temperature at the inside wall of the furnace is preferably held within a range of 200 to 1,000°C.
  • a temperature of at least 500°C at which spontaneous ignition of organic materials occurs is preferred.
  • the burner in the combustion furnace of the invention may be an external-mixing twin-fluid atomizing burner like that shown in FIGS. 1 to 3
  • FIG. 4 illustrates a burner not according to the present invention but shown for comparison in which the liquid emitting central tube has a pressure atomizing configuration, and the flame-generating burner main body has a circularly concentric multi-tube construction composed of three tubes.
  • This burner main body has a liquid-emitting central tube 21, and first and second outer tubes 22 and 23, each of which emits a combustion-supporting gas or a combustion-supporting gas-containing non-combustible gas and is disposed concentrically outside of the central tube 21.
  • a liquid is supplied to the central tube 21 from a combustible liquid feed port 14, and a combustion-supporting gas such as air or oxygen and/or a non-combustible gas such as nitrogen are supplied to the first and second outer tubes 22 and 23 from respective gas feed ports 15 and 16.
  • a flame holder 17 is disposed inside the tip portion of the first outer tube 22 so as to be positioned in front of the central tube 21.
  • the flame holder 17, as shown in FIG. 5 is shaped as a conical plate having an opening 17a at the center. If necessary, the plate may bear a plurality of holes, or may have a plurality of blades or projections thereon. The atomized mixture emitted from behind the flame holder 17 must pass through the opening 17a and emerge in front of the flame holder 17.
  • the pressure-atomizing burner shown in FIG. 4 has the following construction.
  • the flow rate of combustion-supporting gas and/or non-combustible gas for covering the flame is preferable for the flow rate of combustion-supporting gas and/or non-combustible gas for covering the flame to be within a suitable range which is at least sufficient to shield the flame from combustion gases present within the combustion furnace, yet is not so excessive as to hinder combustion.
  • a suitable range which is at least sufficient to shield the flame from combustion gases present within the combustion furnace, yet is not so excessive as to hinder combustion.
  • the velocity of the fluid emitted from each tube in the multi-tube arrangement is regulated within, a range in velocity which is at least sufficient to maintain good atomization yet not so excessive as to hinder combustion.
  • the velocity of combustible liquid emission from the central tube is preferably set at from 5 to 250 m/s, and especially from 5 to 50 m/s in the case of pressure atomization.
  • the velocity of gas emission from the first and second outer tubes is preferably set at from 5 to 50 m/s when air is used in a pressure-atomizing burner.
  • the amount of combustion-supporting gas supplied between the outer tubes and the burner tile, relative to the substance being burned that is emitted from the central tube, is preferably 0.5 to 5.0 times the stoichiometric amount. To hold the flame stable, it is even more preferable to set the amount of combustion-supporting agent at from 0.8 to 2.0 times the stoichiometric amount.
  • the liquid is atomized by being emitted at the above-indicated velocity and a temperature and pressure below the boiling point and by emission of the combustion-supporting gas and/or non-combustible gas from the first outer tube at the above-indicated velocity and a temperature of 0 to 30°C.
  • the resulting atomized mixture is burned, and the flame thus generated is covered, with the combustion-supporting gas and/or non-combustible gas emitted from the second and subsequent outer tubes and also from between the burner tile and the outermost tube.
  • the temperature of the combustion-supporting gas and/or non-combustible gas emitted from the second and subsequent outer tubes and from between the burner tile and the outermost tube is preferably from 0 to 30°C.
  • a plurality of burners having the construction of the invention may be installed at the interior of a single burner tile. Moreover, the burner tile may be preheated to improve the fluidity of the combustible liquid and of the combustion-supporting gas and non-combustible gas supplied to the burner, as well as for other reasons, such as controlling combustion.
  • FIG. 6 illustrates an embodiment of a combustion furnace which can be used with burners according to the present invention, and specifically a vertical cylindrical furnace having at the top a pressure-atomizing three-tube burner, a water-spraying nozzle for temperature regulation, and a movable scraper driving mechanism.
  • the furnace is provided in a barrel portion thereof with soot blowers and a movable scraper.
  • This combustion furnace has a furnace main body 18 in which there is disposed at the top thereof a burner like that shown in FIG. 4 comprising a central tube 21 and outer tubes 22 and 23.
  • the burner supplies and ignites an S liquid and a combustion-supporting gas such as air or oxygen, thereby burning the S liquid and forming a solid oxide within the furnace main body 18.
  • the furnace main body 18 is provided on a sidewall thereof with a water-spraying nozzle 19 for cooling.
  • the nozzle 19 sprays water to allow combustion to continue while keeping the combustion temperature in the furnace main body 18 within a range where the S element oxide does not melt or sinter.
  • soot blowers 24 are installed at suitable positions on the sidewall of the furnace main body 18 where S element oxide powder formed by combustion deposits and builds up. The soot blowers 24 are periodically operated at fixed intervals of time to knock down S element oxide powder from the furnace wall. The knocked down powder is discharged together with combustion gases from an exhaust opening 25 at the bottom of the furnace main body 18.
  • An annular movable scraper 26 is normally situated within the furnace main body 18 at the top thereof.
  • the scraper 26 is coupled by a chain 27 to a drive mechanism 28 located outside of the furnace main body 18. Operation of the drive mechanism 28 causes the chain 27 to wind onto or play out from the drive mechanism 28, causing the scraper 26 to slide upward or downward along the inner peripheral wall surface of the furnace main body 18 so as to knock down any S element oxide powder that has deposited and built up on the walls of the furnace main body 18 and has not been removed by the soot blowers 24.
  • a burner tile may be provided in the manner described above.
  • Temperature control within the illustrated furnace is carried out by a water spraying system but, as noted earlier, any suitable mechanism which maintains the inside wall surface at a temperature at which the S element oxide powder does not melt or sinter may be used.
  • Illustrative examples include a direct cooling system such as water-cooled walls, and methods involving the supply of cold air.
  • any other suitable method may be used without particular limitation so long as it is a mechanism which knocks down such powder from the inside surfaces of the furnace walls.
  • Illustrative examples include a method in which heat-resistant spheres are dropped from the top of the furnace and a method that involves vibrating the entire furnace.
  • the type of furnace used in the present embodiment is a vertical cylindrical furnace which burns only liquids containing S element-bearing compounds. However, if the combustion furnace must also be fed other liquids and/or solids at the same time, use may be made of any suitable type of furnace, provided this has the mechanisms critical to the practice of the invention, as noted below.
  • the combustion furnace shown in FIG. 6 has a construction which includes the following features.
  • Tetramethoxysilane was burned under the following conditions using a burner of the construction shown in FIGS. 1 to 3 .
  • Central tube (stainless steel): bore, 8 mm; bore at discharge orifice, 4 mm
  • First outer tube stainless steel: bore, 20 mm; bore at discharge orifice, 8 mm
  • Second outer tube stainless steel: bore, 32 mm; bore at discharge orifice, 28 mm
  • Tetramethoxysilane combustion was carried out under the same conditions as in Example 1 using a burner which was similar but had a two-tube construction without a second outer tube.
  • Tetramethoxysilane gas obtained by vaporizing tetramethoxysilane with an evaporator was burned under the following conditions using the burner described in Comparative Example 1.
  • Tetramethoxysilane (Si(OCH 3 ) 4 ) combustion was carried out under the following conditions using a burner of the construction shown in FIG. 4 .
  • Tetramethoxysilane combustion was carried out under the same conditions as in Comparative Example 3 using a burner which was similar but had a two-tube construction without a second outer tube.
  • silicon dioxide powder continued to settle onto the surface of the flame holder and onto the outside and tip of the first outer tube for as long as combustion continued. After about 2 hours, the surface of the flame holder and the front of the first outer tube became almost entirely obstructed by silicon dioxide, at which point combustion could no longer be continued.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)

Claims (18)

  1. Verbrennungsverfahren zur Zerstäubung und Verbrennung oder Flammenhydrolyse einer brennbaren Flüssigkeit, die ein chemisches Element enthält, das bei einer solchen Verbrennung oder Flammenhydrolyse ein Festoxid bildet, unter Verwendung einer Brenneranordnung mit einem Brenner mit einem kreisförmig-konzentrischen Mehrrohraufbau mit drei oder mehreren Rohren,
    mit einem zentralen Rohr (1, 21), das sich auf eine Spitze hin verjüngt und an seiner Spitze einen Zerstäubungsmechanismus aufweist;
    einem ersten äußeren Rohr (2, 22), das konzentrisch außerhalb des zentralen Rohrs angeordnet ist, und einem zweiten äußeren Rohr (3, 23), das konzentrisch außerhalb des ersten äußeren Rohrs angeordnet ist;
    wobei der Spitzenabschnitt des ersten und des zweiten äußeren Rohrs jeweils so geformt ist, dass er sich auf eine Spitze hin verjüngt; und wobei
    (a) die Spitze des ersten äußeren Rohrs (2) in Bezug auf die Spitze des zentralen Rohrs (1) nach hinten versetzt ist und die Spitze des zweiten äußeren Rohrs (3) in Bezug auf die Spitze des ersten äußeren Rohrs (2) nach hinten versetzt ist, wobei die Spitzen der äußeren Rohre (2, 3) sich zu ihrer jeweiligen Spitze hin verjüngen, oder
    (b) die Spitzen der äußeren Rohre (22, 23) in Bezug auf die Spitze des zentralen Rohrs (21) vorstehen;
    wobei die Brenneranordnung gegebenenfalls den Brenner in einer durch einen Brennerstein (4) hindurch verlaufenden Öffnung befestigt aufweist, wobei ein Abstand zwischen dem äußersten Rohr des Brenners und dem Brennerstein vorliegt, der einen Gasdurchlass (7) um den Brenner definiert;
    wobei im Zuge des Verfahrens:
    die brennbare Flüssigkeit in das zentrale Rohr (1, 21) zugeführt wird und in zerstäubter Form aus dem Zerstäubungsmechanismus an dessen Spitze mit etwa 5 bis 250 m/s ausgestoßen wird;
    die Verbrennung unterstützendes Gas oder die Verbrennung unterstützendes Gas und nicht brennbares Gas mit 1 bis 250 m/s aus dem ersten äußeren Rohr ausgestoßen wird, und die Verbrennung unterstützendes Gas und/oder nicht brennbares Gas mit 1 bis 250 m/s aus dem zweiten äußeren Rohr ausgestoßen wird und gegebenenfalls aus allen weiteren äußeren Rohren und dem gegebenenfalls vorhandenen Gasdurchlass (7), und
    die zerstäubte Flüssigkeit aus dem zentralen Rohr (1, 21) in aus den äußeren Rohren und dem gegebenenfalls vorhandenen Gasdurchlass (7) zugeführtem, die Verbrennung unterstützendem Gas verbrennt, während die resultierende Flamme durch aus den äußeren Rohren und dem gegebenenfalls vorhandenen Gasdurchlass (7) ausgestoßenen Gasströmen abgedeckt ist.
  2. Verbrennungsverfahren nach Anspruch 1, worin das chemische Element, das durch Verbrennung oder Flammenhydrolyse ein Festoxid bildet, ein Element der Gruppe 1A (außer Wasserstoff), der Gruppe 2A, der Gruppe 3B, der Gruppe 4B, der Gruppe 5B, der Gruppe 6B, der Gruppe 7B, der Gruppe 8, der Gruppe 1B, der Gruppe 2B, der Gruppe 3A, der Gruppe 4A (außer Kohlenstoff), der Gruppe 5A (außer Stickstoff) oder der Gruppe 6A (außer Sauerstoff und Schwefel) der CAS-Version der Langform des Periodensystems der Elemente ist.
  3. Verbrennungsverfahren nach Anspruch 2, worin das chemische Element das durch Verbrennung oder Flammenhydrolyse ein Festoxid bildet, Silicium ist.
  4. Verbrennungsverfahren nach Anspruch 3, worin die Flüssigkeit eine flüssige organische Siliciumverbindung ist.
  5. Verbrennungsverfahren nach Anspruch 3 oder 4, worin die Menge der die Verbrennung unterstützenden Gase in Bezug auf die Menge der Substanz, die verbrannt wird, dem 0,5- bis 5fachen der stöchiometrischen Menge entspricht.
  6. Verbrennungsverfahren nach einem der Ansprüche 1 bis 5, worin das die Verbrennung unterstützende Gas Sauerstoff oder Luft ist.
  7. Verbrennungsverfahren nach einem der vorangegangenen Ansprüche, worin der Brennerstein (4) außerhalb des zweiten äußeren Rohrs (3) vorliegt, um den Gasdurchlass (7) um den Brenner zwischen dem zweiten äußeren Rohr (3) und dem Brennerstein (4) zu definieren.
  8. Verbrennungsverfahren nach einem der vorangegangenen Ansprüche, worin der Brenner die Spitze des ersten äußeren Rohrs (2) in Bezug auf die Spitze des zentralen Rohrs (1) nach hinten versetzt aufweist und die Spitze des zweiten äußeren Rohrs (3) in Bezug auf die Spitze des ersten äußeren Rohrs (2) nach hinten versetzt aufweist.
  9. Verbrennungsverfahren nach einem der vorangegangenen Ansprüche, worin die Spitze des ersten äußeren Rohrs (22) in Bezug auf die Spitze des zentralen Rohrs (21) vorsteht und die Spitze des zweiten äußeren Rohrs (23) in Bezug auf die Spitze des ersten äußeren Rohrs (22) vorsteht.
  10. Verbrennungsverfahren nach einem der vorangegangenen Ansprüche, worin die Spitzen der äußeren Rohre (22, 23) in Bezug auf die Spitze des zentralen Rohrs (21) vorstehen und die Brenneranordnung einen Flammenstabilisator (17) umfasst, der vor dem zentralen Rohr (21) und innerhalb der nach vorne vorstehenden Spitzen der äußeren Rohre (22, 23) bereitgestellt ist.
  11. Verbrennungsverfahren nach einem der vorangegangenen Ansprüche, worin die Brenneranordnung in einem Verbrennungsofen (14) vorliegt, der Folgendes umfasst:
    - Mittel (19), um die Oberflächentemperatur einer Innenwand des Ofens oder etwaiger Festoxidabscheidungen auf dieser Innenwand unter einem Schmelzpunkt oder der Temperatur zu halten, bei der solche Abscheidungen klebrig werden;
    und/oder
    - Mechanismen (24, 26, 27, 28), um Festoxidabscheidungen von der Innenwand des Ofens zu entfernen.
  12. Verbrennungsverfahren nach Anspruch 11 und 3, worin die Innenwand des Ofens auf einer Temperatur von 200 °C bis 1.000 °C gehalten wird.
  13. Brenneranordnung, die geeignet ist, um ein Verfahren nach einem der Ansprüche 1 bis 7 durchzuführen und Folgendes umfasst:
    einen Brenner mit kreisförmig-konzentrischem Mehrrohraufbau aus drei oder mehr Rohren,
    mit einem zentralen Rohr (1, 21), das sich auf eine Spitze hin verjüngt und an seiner Spitze einen Zerstäubungsmechanismus aufweist, um die zerstäubte brennbare Flüssigkeit abzugeben;
    einem ersten äußeren Rohr (2, 22), das konzentrisch außerhalb des zentralen Rohrs angeordnet ist, und einem zweiten äußeren Rohr (3, 23), das konzentrisch außerhalb des ersten äußeren Rohrs angeordnet ist, wobei der Spitzenabschnitt des ersten und des zweiten äußeren Rohrs jeweils so geformt ist, dass er sich auf eine Spitze hin verjüngt;
    wobei die Brenneranordnung gegebenenfalls auch einen äußeren Gasdurchlass (7) bereitstellt, der durch einen Abstand zwischen dem äußersten Rohr (3, 23) des Brenners und einer Öffnung in einem Brennerstein (4), in dem der Brenner angebracht ist, bereitgestellt ist;
    und wobei
    (a) die Spitze des ersten äußeren Rohrs (2) in Bezug auf die Spitze des zentralen Rohrs (1) nach hinten versetzt ist und die Spitze des zweiten äußeren Rohrs (3) in Bezug auf die Spitze des ersten äußeren Rohrs (2) nach hinten versetzt ist, wobei die Spitzen der äußeren Rohre (2, 3) sich zu ihrer jeweiligen Spitze hin verjüngen, oder
    (b) die Spitzen der äußeren Rohre (22, 23) in Bezug auf die Spitze des zentralen Rohrs (21) vorstehen;
    so dass Gas, das aus den äußeren Rohren (2, 3, 22, 23) und dem gegebenenfalls vorhandenen Gasdurchlass (7), wenn dieser vorhanden ist, ausgestoßen wird, eine bei Betrieb durch die Verbrennung von zerstäubter Flüssigkeit, die aus dem zentralen Rohr (1, 21) ausgestoßen wird, erzeugte Flamme abdecken kann.
  14. Brenneranordnung nach Anspruch 13, wobei Option (b) vorliegt, bei der die Spitze des ersten äußeren Rohrs (22) in Bezug auf das zentrale Rohr (21) vorsteht und die Spitze des zweiten äußeren Rohrs (23) in Bezug auf die Spitze des ersten äußeren Rohrs (22) vorsteht.
  15. Brenneranordnung nach Anspruch 14, die ferner einen Flammenstabilisator (17) umfasst, der vor dem zentralen Rohr (21) und innerhalb der nach vorne vorstehenden Spitzen der äußeren Rohre (22, 23) bereitgestellt ist.
  16. Brenneranordnung nach einem der Ansprüche 13 bis 15, die den Brennerstein (4) außerhalb des zweiten äußeren Rohrs (3) umfasst, wobei der äußere Gasdurchlass (7) zwischen dem zweiten äußeren Rohr (3) des Brenners und der Öffnung des Brennersteins (4) definiert ist.
  17. Verbrennungsofen, der eine Brenneranordnung nach einem der Ansprüche 13 bis 16 umfasst.
  18. Verbrennungsofen nach Anspruch 17, der Folgendes umfasst:
    - Mittel (19), um die Oberflächentemperatur einer Innenwand des Ofens oder etwaiger Festoxidabscheidungen auf dieser Innenwand unter einem Schmelzpunkt oder der Temperatur zu halten, bei der solche Abscheidungen klebrig werden;
    und/oder
    - Mechanismen (24, 26, 27, 28), um Festoxidabscheidungen von der Innenwand des Ofens zu entfernen.
EP99912120A 1999-04-06 1999-04-06 Brenner und ofen für verbrennung und flammhydrolyse und verbrennungsverfahren Expired - Lifetime EP1087177B1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP1999/001821 WO2000060286A1 (fr) 1999-04-06 1999-04-06 Bruleur et four a combustion de combustion et d'hydrolyse a la flamme, et procede de combustion correspondant

Publications (3)

Publication Number Publication Date
EP1087177A1 EP1087177A1 (de) 2001-03-28
EP1087177A4 EP1087177A4 (de) 2002-08-21
EP1087177B1 true EP1087177B1 (de) 2011-12-28

Family

ID=14235414

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99912120A Expired - Lifetime EP1087177B1 (de) 1999-04-06 1999-04-06 Brenner und ofen für verbrennung und flammhydrolyse und verbrennungsverfahren

Country Status (2)

Country Link
EP (1) EP1087177B1 (de)
WO (1) WO2000060286A1 (de)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2889578B1 (fr) * 2005-08-04 2007-09-21 Air Liquide Procede de combustion d'un combustible liquide a atomisation etagee
WO2011016800A1 (en) * 2009-08-03 2011-02-10 Dow Global Technologies Inc. Atomizer nozzle assembly for use with fluidized bed apparatus

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5523067A (en) * 1978-08-07 1980-02-19 Nippon Telegr & Teleph Corp <Ntt> Forming method for oxide powder layer for optical fiber
JPH04362034A (ja) * 1991-06-05 1992-12-15 Sumitomo Electric Ind Ltd ガラス微粒子堆積体の製造方法
US5743723A (en) * 1995-09-15 1998-04-28 American Air Liquide, Inc. Oxy-fuel burner having coaxial fuel and oxidant outlets
WO1997022553A1 (en) 1995-12-19 1997-06-26 Corning Incorporated Method and apparatus for forming fused silica by combustion of liquid reactants
JP3908818B2 (ja) * 1997-03-13 2007-04-25 大陽日酸株式会社 排ガスの処理方法
JP3362632B2 (ja) * 1997-03-26 2003-01-07 信越化学工業株式会社 シラン類含有ガスの処理方法
EP0978487A3 (de) * 1998-08-07 2001-02-21 Corning Incorporated Brenner mit abgedichtetem Kopf und ohne Vormischung für die Abscheidung von Quarzglas

Also Published As

Publication number Publication date
EP1087177A1 (de) 2001-03-28
WO2000060286A1 (fr) 2000-10-12
EP1087177A4 (de) 2002-08-21

Similar Documents

Publication Publication Date Title
US5092760A (en) Oxygen-fuel burner assembly and operation
TWI439642B (zh) 液態燃料燃燒方法及設備
US5269236A (en) Method and apparatus for preventing the adhesion of dust in an incinerator or melting furnace
CN1997439A (zh) 用于控制气体污染物燃烧的装置和方法
US20040216494A1 (en) Burner for combustion or flame hydrolysis, and combustion furnace and process
JP3346267B2 (ja) 燃焼又は火炎加水分解用燃焼炉及び燃焼方法
RU2198349C2 (ru) Способ и реактор для сжигания горючих материалов
EP1087177B1 (de) Brenner und ofen für verbrennung und flammhydrolyse und verbrennungsverfahren
US6422160B1 (en) Apparatus for the combustion of vanadium-containing fuels
US6186410B1 (en) Lance for heating or ceramic welding
US4194454A (en) Method for incinerating sludges
KR102429928B1 (ko) 금속 가공용 노를 가열하기 위한 방법 및 버너
JP3346266B2 (ja) 燃焼又は火炎加水分解用バーナー及び燃焼方法
JPH0252170B2 (de)
KR20190115662A (ko) 폐액 소각용 분무 노즐
UA76740C2 (uk) Спосіб обробки шламу з частинками, що містять метал, оксид металу чи гідроксид металу, і апарат для здійснення даного способу
RU2591940C2 (ru) Способ и устройство для изготовления ацетилена и синтез-газа
JP2699778B2 (ja) 溶射補修装置
JP3551604B2 (ja) 火炎溶射方法
KR100236539B1 (ko) 폐액 분무 소각 버너
JP3574967B2 (ja) 固形廃棄物の溶融処理及び廃油の部分燃焼処理方法
JPH0631217A (ja) 二流体噴霧ノズル
SU875183A1 (ru) Устройство дл огневого обезвреживани жидких горючих отходов
SU953373A1 (ru) Шахтна печь дл переработки фосфорсодержащих шламов
RU2222570C1 (ru) Способ удаления кокса и ингибирования коксообразования в печах пиролиза и устройство для его осуществления

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20001006

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

A4 Supplementary search report drawn up and despatched

Effective date: 20020710

AK Designated contracting states

Kind code of ref document: A4

Designated state(s): DE FR GB

RIC1 Information provided on ipc code assigned before grant

Free format text: 7C 03B 37/014 A, 7C 03B 19/14 B

17Q First examination report despatched

Effective date: 20030205

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 69943956

Country of ref document: DE

Effective date: 20120308

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20121001

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 69943956

Country of ref document: DE

Effective date: 20121001

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 18

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 19

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20170313

Year of fee payment: 19

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20170405

Year of fee payment: 19

Ref country code: DE

Payment date: 20170329

Year of fee payment: 19

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 69943956

Country of ref document: DE

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20180406

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20181101

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180406

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180430