[go: up one dir, main page]

EP0126001B1 - Process and apparatus for the treatment of fuel in a fluidized bed - Google Patents

Process and apparatus for the treatment of fuel in a fluidized bed Download PDF

Info

Publication number
EP0126001B1
EP0126001B1 EP84400961A EP84400961A EP0126001B1 EP 0126001 B1 EP0126001 B1 EP 0126001B1 EP 84400961 A EP84400961 A EP 84400961A EP 84400961 A EP84400961 A EP 84400961A EP 0126001 B1 EP0126001 B1 EP 0126001B1
Authority
EP
European Patent Office
Prior art keywords
temperature
zone
plant
fluidized bed
particles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP84400961A
Other languages
German (de)
French (fr)
Other versions
EP0126001A1 (en
Inventor
Gérard Chrysostome
Robert Wang
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.)
Creusot Loire SA
Original Assignee
Creusot Loire SA
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 Creusot Loire SA filed Critical Creusot Loire SA
Priority to AT84400961T priority Critical patent/ATE32606T1/en
Publication of EP0126001A1 publication Critical patent/EP0126001A1/en
Application granted granted Critical
Publication of EP0126001B1 publication Critical patent/EP0126001B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/46—Gasification of granular or pulverulent flues in suspension
    • C10J3/54—Gasification of granular or pulverulent fuels by the Winkler technique, i.e. by fluidisation
    • C10J3/56—Apparatus; Plants
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/46—Gasification of granular or pulverulent flues in suspension
    • C10J3/48—Apparatus; Plants
    • C10J3/482—Gasifiers with stationary fluidised bed
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/46—Gasification of granular or pulverulent flues in suspension
    • C10J3/54—Gasification of granular or pulverulent fuels by the Winkler technique, i.e. by fluidisation
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10K—PURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
    • C10K1/00—Purifying combustible gases containing carbon monoxide
    • C10K1/02—Dust removal
    • C10K1/026—Dust removal by centrifugal forces
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00—Details of gasification processes
    • C10J2300/18—Details of the gasification process, e.g. loops, autothermal operation
    • C10J2300/1807—Recycle loops, e.g. gas, solids, heating medium, water
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00—Details of gasification processes
    • C10J2300/18—Details of the gasification process, e.g. loops, autothermal operation
    • C10J2300/1861—Heat exchange between at least two process streams

Definitions

  • the subject of the invention is an improved process and installation for treating a combustible material in a fluidized bed, applicable in particular to the gasification of coal.
  • a fluidized granular material treatment installation normally consists of a vertical reaction chamber supplied with granular combustible materials and provided at its base with means for injecting a fluidizing gas, the circulation speed of which can be adjusted by acting on the injection rate.
  • the reaction chamber opens into a smoke evacuation circuit which includes a gas outlet pipe opening into a device for recovering solid particles entrained with the gases.
  • This recovery device can for example be a cyclone which comprises an upper orifice for leaving gases and very fine particles and a lower orifice for leaving solid particles having a dimension greater than a certain limit which depends on the performance of the recovery device.
  • the solid particles thus recovered are returned to the fluidized bed, at the base of the reaction chamber, by a recycling circuit. In this way, the incompletely burned particles are recycled at the base of the reaction chamber, in the combustion zone, the fumes causing only the finest ashes.
  • the operating mode of the fluidized beds is linked to the injection rate and to the gas circulation speed. If the injection rate is adjusted so that the gas speed is only a little higher than the critical speed from which fluidization begins, most of the solid particles remain at the base of the reaction chamber under form a dense fluidized bed, only very fine particles being entrained with the gases.
  • the fluidization speed exceeds a limit which depends on the average size of the particles and which is of the order of 4 m / s, most of the particles are entrained with the fumes and then a distinction is made between inside the reaction chamber a dense lower zone surmounted by a dilute zone traversed by an ascending current of gases and particles which escapes through the outlet pipe, the solid particles being separated from the gases in the recovery device and returned to the dense area of the fluidized bed, at the base of the reaction chamber, by the recycling circuit. We then have a so-called running bed operation.
  • Circulating fluidized beds have a number of known advantages. In particular, they allow greater power than ordinary dense beds, the volume of the combustion chamber being better used since the reaction can occur not only in the dense bed, at the bottom of the reaction chamber, but also in the given area. ' The circulating beds are also more flexible because they make it possible to vary the speed of the gases, and to adjust the circulation rate and therefore the residence time of the fuel.
  • the efficiency of a combustible material treatment installation and in particular of a gasification installation depends on the average residence time of the particles which must be greater than the gasification time, the latter depending on the nature of the fuel and the average particle size.
  • DE-C-919 004 discloses a gasifier comprising a chamber in which a fluidized bed is provided above a fluidization grid.
  • This assembly comprises, below the grid, gasification means with endothermic reaction and, above the grid, gasification means with exothermic reaction.
  • the dust entrained by the gases is recovered in a cyclone and reintroduced into the fluidized bed.
  • a coolant is introduced to the upper part of the gasification chamber so as to avoid the deposit of sticky ash on the walls.
  • the high temperature zone is limited to the dense fluidized bed where one can reach a temperature from which the ash gradually agglomerates.
  • This has the advantage of allowing the disposal of the ashes having formed blocks of a certain size and which can be removed by a purge placed at the base of the reaction chamber.
  • the homogenisation of temperatures may not be effective enough to prevent localized overheating and therefore happens in some regions in a fusion of ash that can go all the blocking of the reactor.
  • the invention relates to a new method for operating in a circulating bed at the highest possible temperature so that the particles remain as long as possible at this high temperature without risk of sticking.
  • the temperature is relatively uniform over the entire circuit of materials
  • This cooling does not significantly decrease the yield of the reaction since the high temperature is maintained not only in the dense area of the fluidized bed but also in the diluted area.
  • the reaction can thus take place as long as possible at high temperature, the risk of sticking being less in the zones where the particles are in agitation and separated from each other.
  • reaction temperature it is therefore possible to adjust the reaction temperature to the highest possible level and in particular to a level allowing the agglomeration of the ash into blocks capable of being removed by known means, without however reaching the melting temperature which would risk cause a blockage of the reactor.
  • the bonding temperature depends on the operating conditions and therefore, having observed these, it will be possible to determine in each zone of the installation, according to the circumstances specific to this zone, the temperature limit at not to exceed.
  • the temperatures will preferably be controlled in at least one zone A at the base of the reaction chamber, that is to say in the dense zone of the fluidized bed, a zone B slightly above the level limit of the dense zone, a zone C in the diluted zone, at the upper part of the reaction chamber and a zone D just upstream of the recovery device.
  • a cold product in divided form will be injected into it, which may consist, for example, of water spray or steam, of particles recovered and cooled before being recycled in the fluidized bed or by a part of the gas produced, taken at the outlet of the recovery device and recycled in the desired zone after cooling.
  • the cold product injected can also consist of at least part of the combustible material introduced into the upper part of the diluted zone in the reaction chamber with an adjustable flow rate so that the coarsest particles fall into the dense zone. of the fluidized bed while crossing the diluted zone, the particles the finest being entrained with the fumes to the recovery device and then recycled into the fluidized bed.
  • the invention also covers an improved installation for processing combustible material, conventionally constituted by a vertical reaction chamber provided with means for supplying solid combustible material and, at its base, means for fluidization by injection of a gas with an adjustable flow rate and connected at its upper part, by a flue outlet pipe to a device for recovering entrained solid materials, comprising an upper outlet, a lower outlet for solid particles connected by a recycling circuit to the base of the reaction chamber.
  • the installation comprises, upstream of the recovery device, a plurality of zones (A, B, C, D, ...) of temperature control, staggered in the direction of circulation of the gases and materials and each covering the entire cross section of the gas passage at the level in question, each control zone (A, B, C, D, ...) being provided with a means of measuring the average ambient temperature and a means of cooling causing a localized lowering of this ambient temperature in the zone considered and that the temperature measurement and cooling means of the control zones are associated with a regulation device comprising a set of comparators of the temperatures measured with reference temperatures determined in depending on the desired operating conditions in each control zone (A, B, C, D, ...), a set of adjustment means for the cooling means and a means for controlling the adjustment means in function ction of the differences observed between the measured temperatures and the reference temperatures.
  • the single figure schematically represents a gasification plant for coal in a fluidized bed provided with improvements according to the invention.
  • the gasification installation essentially comprises a reaction chamber 1 in the form of a column, consisting of an elongated cylindrical enclosure with a vertical axis provided at its base with a grid for the homogeneous distribution of a fluidization gas introduced below the grate with a flow rate adjustable by injection means 11.
  • the reaction chamber 1 is connected at its upper part, by a flue outlet pipe 12, to a device 2 for recovering entrained solid particles, for example a dust collector cyclone comprising an upper outlet 21 for the gases and a lower outlet 22 for the recovered particles which opens into a recycling pipe 23 connected to the base of the chamber 1 by a device for reinjecting solid particles consisting for example of a siphon 24 in which can be injected into a gas allowing adjustment of the reinjection rate.
  • the combustible material, stored in a hopper 13 is introduced at the base of the combustion chamber, into the fluidized bed, for example by means of a screw feed device 14 making it possible to adjust the feed rate by acting on the speed of rotation of the screw.
  • a purge line 18 placed at the lower end of the combustion chamber 1 makes it possible to remove the agglomerated ash.
  • the flow rate of the fluidizing gas injection member 11 is adjusted so that the installation operates in a circulating bed, the gas circulation speed being greater than 4 m / s so that the gases entrain the most large part of the solid particles which then occupy the entire height of the column 1 inside which there is a lower zone 15 in the dense phase and an upper zone 16 in the diluted phase.
  • the combustible material introduced into the chamber 1 is divided into two parts: the finer particles are immediately entrained with the gases while the larger particles fall into the dense zone 15 and remain there until, after partial combustion, they reach a dimension which allows them to be trained in turn.
  • the dense zone can also contain an inert granular material serving as a support for fluidization or else having a role in the reaction.
  • the solid particles entrained in the outlet pipe 12 are stopped in the recuperator 2 and then recycled in the fluidized bed through the pipe 24.
  • control zones (A, B, C, D) are placed respectively, on the one hand at least at three levels of the reaction chamber 1, respectively in (A) in the dense part of the fluidized bed, in (B) at the boundary surface of it and in
  • the dense area of the fluidized bed contains the largest particles of fuel and inert material and is traversed by the recycled fine particles consisting of incompletely burnt material and ash. It is desirable to maintain in this zone a temperature for which the ashes are sufficiently softened to allow their agglomeration, however, avoiding their merger or solidification. In fact, by agglomerating, the ash forms blocks which are easier to remove, but too high a temperature rise could cause the ash to melt and stick together between them and on the walls of the reactor with the risk of blocking it.
  • the solid particles carried away by the gaseous fluid are found at substantially the same temperature as in the dense zone 15 and are therefore agglomerating: their concentration being lower and their agitation significant, the tendency to agglomeration is less but it is also necessary to avoid sticking of the particles on the walls of the reactor, in particular in the critical zones which it is possible to locate.
  • a number of temperature sensors 31, 32, 33, 34 can be placed in the most sensitive parts of the installation.
  • a sensor 31 was placed in the center of the dense area 15, a sensor 32 at the bottom of the diluted area 16, slightly above the limit level of the dense area, a sensor 33 at the upper end of the reaction chamber 1, near the outlet flue and a sensor 34 at the inlet of the recuperator 2 near the wall.
  • the set of sensors is connected to a measuring device 3 providing at its output signals corresponding to the temperatures measured by each of the sensors, which are applied to a set of members 41, 42, 43, 44 for comparing each signal of temperature with a displayed signal corresponding to the reference temperature determined for the zone considered.
  • This intervention means consists, in the example shown, of a cooling circuit 5 comprising a fan 51, the supply line 52 of which is connected to the sheath 26 of the gas outlet from the separator 2 in order to take off part of the evacuated gases, these having preferably been cooled by means of an exchanger 27 placed on the outlet sheath 26 upstream of the supply line 52.
  • the discharge line 5 of the fan 51 is divided into a number of branches 6 provided at their ends with injectors 61, 62, 63, 64 opening into the various zones of the installation, substantially at the height of the corresponding temperature sensor.
  • each injection branch 6 with a plurality of injectors distributed regularly in a plane transverse to the axis so that the injected cooling fluid is spread evenly throughout the cross section of the installation at the height of the area considered.
  • the members 61 62, 63, 64 make it possible to inject a product in divided form throughout the zone and at a temperature below the temperature measured in the control zone. Given the homogenizing effect of the temperatures obtained in addition by the use of a high fluidization speed, it will thus be possible to control the temperature fairly precisely inside each zone of the installation, on the entire cross section of the gas passage.
  • each branch 6 of the cooling circuit will be provided with a valve 71, 72, 73, 74 controlled by a computer 7 as a function of the temperature differences measured by the comparators 41, 42, 43, 44.
  • the computer 7 is programmed to take account of the interactions between the zones, any cooling in one zone having repercussions in the following zones.
  • the temperature control of the different zones is obtained by injecting a portion of the fumes sampled at the outlet of the separator, after cooling to a temperature below ambient temperature in the different zones of the installation.
  • a fluid cooling agent such as water vapor or water spray
  • the latter could for example be provided with an exchanger 28 making it possible to bring the temperature of the recycled particles at the desired level.
  • solid particles or water are preferably injected in the gas or liquid phase to control agglomeration.
  • water or recycled gas will be injected, via the injectors 63 or 64, to avoid sticking and accumulation in the separator.
  • the injections individually or in combination with one another, by acting either on the flow rate injected if the cooling agent is a gas or water spray, or, preferably, on the temperature if the coolant consists of recycled solid particles.
  • part of the fuel taken from the feed circuit thereof and injected at 17, preferably at the top of the diluted zone 16, can also be used as a cooling product.
  • the installation according to the invention has only been described schematically, the devices used such as the regulation system and the means for cooling and injecting the recycled product being able to be produced with known means.
  • the invention could be the subject of variants and improvements, and, for example, the reaction chamber could be divided into a greater number of temperature control zones staggered from bottom to top to 1 inside the dense zone and especially in the diluted zone of the fluidized bed.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
  • Gasification And Melting Of Waste (AREA)

Abstract

1. Process for a fluidized bed treatment of a fuel in a plant comprising a vertical reaction chamber (1) provided at its base with means (14) for feeding fuel and means (11) for fluidizing by injecting a gas and whose upper end is connected by a gas exit duct (12) to a device (2) for recovering the entrained solid particles comprising an exit orifice (21) for the gases and an exit orifice (22) for the solid particles which are connected by a recycling circuit (23) to the base of the reaction chamber (1), characterized in that, with the nature of the fuel and the operating conditions, such as the shape and the dimensions of the plant, the particle size measurements of the particles and the gas circulation velocities, being taken into account : - a reference temperature is determined, above which the stationary solid particles are liable to adhere to each other inside the recovery device (2), - the fluidization conditions are adjusted to produce a circulating bed regime in the plant, - the reaction temperature in the dense part (15) of the fluidized bed is adjusted to a level above the reference temperature, - the average temperatures are measured in a plurality of temperature control zones (A, B, C, D, etc) placed at intervals in the direction of travel of the gases and of the solids inside the plant, - each measured temperature is compared with the determined reference temperature, and - a lowering of the average temperature is produced locally in any one zone, upstream of the recovery device (2) each time the temperature measured therein reaches the reference temperature, in order to keep the average temperature in each zone continually below the corresponding reference temperature.

Description

L'invention a pour objet un procédé et une installation perfectionnée de traitement d'une matière combustible en lit fluidisé, applicable notamment à la gazéification du charbon.The subject of the invention is an improved process and installation for treating a combustible material in a fluidized bed, applicable in particular to the gasification of coal.

Une installation de traitement de matières granulaires en fluidisé se compose normalement d'une chambre de réaction verticale alimentée en matières conbustibles granulaires et munie à sa base de moyens d'injection d'un gaz de fluidisation dont on peut régler la vitesse de circulation en agissant sur le débit d'injection.A fluidized granular material treatment installation normally consists of a vertical reaction chamber supplied with granular combustible materials and provided at its base with means for injecting a fluidizing gas, the circulation speed of which can be adjusted by acting on the injection rate.

A sa partie supérieure, la chambre de réaction débouche dans un circuit d'évacuation des fumées qui comprend une conduite de sortie des gaz débouchant dans un dispositif de récupération des particules solides entraînées avec les gaz. Ce dispositif de récupération peut être par exemple un cyclone qui comprend un orifice supérieur de sortie des gaz et des particules très fines et un orifice inférieur de sortie des particules solides ayant une dimension supérieure à une certaine limite qui dépend des performances du dispositif de récupération. Les particules solides ainsi récupérées sont renvoyées dans le lit fluidisé, à la base de la chambre de réaction, par un circuit de recyclage. De la sorte, les particules incomplètement brûlées sont recyclées à la base de la chambre de réaction, dans la zone de combustion, les fumées n'entraînant que les cendres les plus fines.At its upper part, the reaction chamber opens into a smoke evacuation circuit which includes a gas outlet pipe opening into a device for recovering solid particles entrained with the gases. This recovery device can for example be a cyclone which comprises an upper orifice for leaving gases and very fine particles and a lower orifice for leaving solid particles having a dimension greater than a certain limit which depends on the performance of the recovery device. The solid particles thus recovered are returned to the fluidized bed, at the base of the reaction chamber, by a recycling circuit. In this way, the incompletely burned particles are recycled at the base of the reaction chamber, in the combustion zone, the fumes causing only the finest ashes.

On sait que le mode de fonctionnement des lits fluidisés est lié au débit d'injection et à la vitesse de circulation des gaz. Si le débit d'injection est réglé de telle sorte que la vitesse des gaz soit seulement un peu supérieure à la vitesse critique à partir de laquelle commence la fluidisation, la plus grande partie des particules solides reste à la base de la chambre de réaction sous forme d'un lit fluidisé dense, seules les particules très fines étant entraînées avec les gaz. En revanche, si la vitesse de fluidisation dépasse une limite qui dépend de la dimension moyenne des particules et qui est de l'ordre de 4 m/s, la plus grande partie des particules est entraînée avec les fumées et l'on distingue alors à l'intérieur de la chambre de réaction une zone inférieure dense surmontée d'une zone diluée parcourue par un courant ascendant de gaz et de particules qui s'échappe par la conduite de sortie, les particules solides étant séparées des gaz dans le dispositif de récupération et renvoyées dans la zone dense du lit fluidisé, à la base de la chambre de réaction, par le circuit de recyclage. On a alors un fonctionnement dit en lit circulant.It is known that the operating mode of the fluidized beds is linked to the injection rate and to the gas circulation speed. If the injection rate is adjusted so that the gas speed is only a little higher than the critical speed from which fluidization begins, most of the solid particles remain at the base of the reaction chamber under form a dense fluidized bed, only very fine particles being entrained with the gases. On the other hand, if the fluidization speed exceeds a limit which depends on the average size of the particles and which is of the order of 4 m / s, most of the particles are entrained with the fumes and then a distinction is made between inside the reaction chamber a dense lower zone surmounted by a dilute zone traversed by an ascending current of gases and particles which escapes through the outlet pipe, the solid particles being separated from the gases in the recovery device and returned to the dense area of the fluidized bed, at the base of the reaction chamber, by the recycling circuit. We then have a so-called running bed operation.

Les lits fluidisés circulants présantant un certain nombre d'avantages connus. En particulier, ils permettant une plus grande puissance que les lits ordinaires denses, la volume de la chambre de combustion étant mieux utilisé puisque la réaction peut se produire non seulament dans le lit dense, à la partie inférieure de la chambre de réaction, mais également dans la zone dituée.'Les lits circulants sont également plus souples car ils permettent de faire varier la vitesse des gaz, et d'ajuster la taux de circulation donc le temps de séjour du combustible. Or, le rendement d'une installation de traitement de matières combustibles et en particulier d'une installation de gazéification dépend du temps de séjour moyen des particules qui doit être supérieur au temps de gazéification, ce dernier dépendant de la nature du combustible et de la dimension moyenne des particules. Il est évident en particulier que si le temps de combustion ou de gazéification est trop important, la masse fluidisée augmante et le niveau limite de la zone dense va monter, ce qui oblige à réduire le débit d'alimentation en matière combustible ou bien à utiliser une chambre de réaction de grande hauteur pour absorber les variations du niveau limite.Circulating fluidized beds have a number of known advantages. In particular, they allow greater power than ordinary dense beds, the volume of the combustion chamber being better used since the reaction can occur not only in the dense bed, at the bottom of the reaction chamber, but also in the given area. ' The circulating beds are also more flexible because they make it possible to vary the speed of the gases, and to adjust the circulation rate and therefore the residence time of the fuel. However, the efficiency of a combustible material treatment installation and in particular of a gasification installation depends on the average residence time of the particles which must be greater than the gasification time, the latter depending on the nature of the fuel and the average particle size. It is evident in particular that if the combustion or gasification time is too long, the increasing fluidized mass and the limit level of the dense zone will rise, which means that the feed rate of combustible material must be reduced or else use must be made. a tall reaction chamber to absorb variations in the limit level.

Pour diminuer le temps de gazéification, on peut jouer sur la dimension des particules et sur la température de réaction. Toutefois, on sait qu'en augmentant la température de réaction, on risque d'atteindre une température à partir de laquelle les particules et en particulier les cendres collent entre elles et sur les parois de l'installation ce qui risque d'amener un blocage de celle-ci. Cette température de collage dépend de la nature de la matière, de sa granulométrie et des conditions de fonctionnement. En effet, on a observé que le risque de collage est moins important dans les zones où les particules sont soumises à une agitation importante et relativement écartées les unes des autres. En revanche, le collage se fait plus facilement dans les zones denses, en particulier lorsque les particules sont immobiles, et c'est le cas du dispositif de récupération des particules solides qui peut ainsi se bloquer facilement.To reduce the gasification time, one can play on the particle size and the reaction temperature. However, it is known that by increasing the reaction temperature, there is a risk of reaching a temperature from which the particles and in particular the ashes stick to each other and to the walls of the installation, which risks causing blockage. of it. This bonding temperature depends on the nature of the material, its particle size and the operating conditions. In fact, it has been observed that the risk of sticking is less significant in the areas where the particles are subjected to significant agitation and relatively spaced from one another. On the other hand, bonding takes place more easily in dense areas, in particular when the particles are stationary, and this is the case of the device for recovering solid particles which can thus be easily blocked.

Dans le fonctionnement des installations de traitement et en particulier de gazéification, on est donc partagé entre la volonté d'augmenter autant que possible la température de réaction pour diminuer le temps de gazéification et le risque de collage des particules.In the operation of treatment and in particular gasification installations, there is therefore a division between the desire to increase the reaction temperature as much as possible to reduce the gasification time and the risk of particle sticking.

On connaît dans le DE-C-919 004 un gazogène comportant une chambre dans laquelle est ménagé un lit fluidisé au-dessus d'une grille de fluidisation. Cet ensemble comporte, au-dessous de la grille, des moyens de gazéification à réaction endothermique et, au-dessus de la grille, des moyens de gazéification à réaction exothermique. Les poussières entraînées par les gaz sont récupérées dans un cyclone et réintroduites dans le lit fluidisé. De plus, on introduit un fluide réfrigérant à la partie supérieure de la chambre de gazéification de façon à éviter le dépôt des cendres collants sur les parois.DE-C-919 004 discloses a gasifier comprising a chamber in which a fluidized bed is provided above a fluidization grid. This assembly comprises, below the grid, gasification means with endothermic reaction and, above the grid, gasification means with exothermic reaction. The dust entrained by the gases is recovered in a cyclone and reintroduced into the fluidized bed. In addition, a coolant is introduced to the upper part of the gasification chamber so as to avoid the deposit of sticky ash on the walls.

Lorsque l'on utilise un lit fluidisé à faible vitesse, la zone à haute température est limitée au lit fluidisé dense où l'on peut atteindre une température à partir de laquelle les cendres s'agglomèrent progressivement. Ceci présente l'avantage de permettre l'évacuation des cendres ayant formé des blocs d'une certaine dimension et qui peuvent être retirés par une purge placée à la base de la chambre de réaction. Cependant, dans un lit fluidisé à faible vitesse, l'homogénéisation des températures peut ne pas être assez efficace pour éviter des surchauffes localisées et on arrive donc dans certaines régions à une fusion des cendres qui peut aller jusqu'au blocage du réacteur.When using a fluidized bed at low speed, the high temperature zone is limited to the dense fluidized bed where one can reach a temperature from which the ash gradually agglomerates. This has the advantage of allowing the disposal of the ashes having formed blocks of a certain size and which can be removed by a purge placed at the base of the reaction chamber. However, in a fluidized li t at low speed, the homogenisation of temperatures may not be effective enough to prevent localized overheating and therefore happens in some regions in a fusion of ash that can go all the blocking of the reactor.

Pour diminuer le risque de fusion des cendres à haute température, on a donc intérêt à augmenter la vitesse de circulation des gaz et l'on arrive à un fonctionnement en lit circulant qui, comme on l'a indiqué, permet d'augmenter la puissance de l'installation pour une taille donnée. Cependant, lorsque l'on fonctionne en lit circulant, du fait, précisément, de la circulation continue de la plus grande partie des particules solides, la température est pratiquement la même dans toutes les parties de l'installation. Or, le risque de collage est plus important dans certaines zones, en particulier dans les conduites de liaison et surtout dans le dispositif de récupération où les particules sont pratiquement immobiles et forment un lit dense. Par conséquent, même en fonctionnant en lit circulant, on est amené à limiter la température de réaction.To reduce the risk of ash melting at high temperature, it is therefore advantageous to increase the speed of circulation of the gases and one arrives at a functioning in circulating bed which, as indicated, allows to increase the power of the installation for a given size. However, when operating in a circulating bed, precisely because of the continuous circulation of most of the solid particles, the temperature is practically the same in all parts of the installation. However, the risk of sticking is greater in certain areas, in particular in the connecting pipes and especially in the recovery device where the particles are practically stationary and form a dense bed. Consequently, even when operating in a circulating bed, it is necessary to limit the reaction temperature.

L'invention a pour objet un nouveau procédé permettant de fonctionner en lit circulant à la température la plus élevée possible de telle sorte que les particules restent le plus longtemps possible à cette haute température sans risque de collage.The invention relates to a new method for operating in a circulating bed at the highest possible temperature so that the particles remain as long as possible at this high temperature without risk of sticking.

Conformément à l'invention, en tenant compte de la nature de la matière combustible et des conditions de fonctionnement telles que la forme et les dimensions de l'installation, la granulométrie des particules et les vitesses de circulation des gaz:

  • - on détermine une température de référence à partir de laquelle les particules de matière immobiles sont susceptibles de se coller les unes aux autres à l'intérieur du dispositif de récupération,
  • - on règle les conditions de fluidisation pour réaliser un fonctionnement de l'installation en lit circulant,
  • - on règle la température de la réaction dans la partie dense du lit fluidisé à un niveau supérieur à la température de référence,
  • - on mesure les températures moyennes dans une pluralité de zones (A, B, C, D,...) de contrôle de températures échelonnées dans le sens de circulation des gaz et des matières à l'intérieur de l'installation,
  • - on compare chaque température mesurée à la température de référence déterminée,
  • - et on produit localement, dans l'une ou l'autre zone, en amont du dispositif de récupération, un abaissement de la température moyenne chaque fois que la température mesurée y atteint la température de référence, pour le maintien permanent de la température moyenne dans chaque zone au-dessous de la température de référence correspondante.
In accordance with the invention, taking into account the nature of the combustible material and the operating conditions such as the shape and dimensions of the installation, the particle size of the particles and the gas circulation speeds:
  • a reference temperature is determined from which the particles of immobile material are capable of sticking to each other inside the recovery device,
  • - the fluidization conditions are adjusted to operate the installation in a circulating bed,
  • the temperature of the reaction in the dense part of the fluidized bed is adjusted to a level higher than the reference temperature,
  • - the average temperatures are measured in a plurality of zones (A, B, C, D, ...) of temperature control staggered in the direction of circulation of the gases and materials inside the installation,
  • - each measured temperature is compared to the determined reference temperature,
  • - and locally, in one or the other zone, upstream of the recovery device, a reduction in the average temperature is produced each time the measured temperature reaches the reference temperature therein, for the permanent maintenance of the average temperature in each zone below the corresponding reference temperature.

Ainsi, alors que, dans un lit circulant, la température est relativement homogène sur tout le circuit des matières, dans le procédé selon l'invention, on peut avoir une haute température jusqu'à l'entrée du dispositif de récupération et produire à ce moment le refroidissement nécessaire à l'abaissement de la température des particules au-dessous du niveau pour lequel pourrait se produire leur collage au moment où les particules sont tassées et relativement immobiles les unes par rapport aux autres. Ce refroidissement ne diminue pas sensiblement le rendement de la réaction étant donné que la haute température est maintenue non seulement dans la zone dense du lit fluidisé mais également dans la zone diluée. La réaction peut ainsi se produire le plus longtemps possible à haute température, le risque de collage étant moindre dans les zones où les particules sont en agitation et écartées les unes des autres.Thus, while, in a circulating bed, the temperature is relatively uniform over the entire circuit of materials, in the process according to the invention, one can have a high temperature up to the inlet of the recovery device and produce at this moment the cooling necessary to lower the temperature of the particles below the level for which their bonding could occur when the particles are compacted and relatively immobile with respect to each other. This cooling does not significantly decrease the yield of the reaction since the high temperature is maintained not only in the dense area of the fluidized bed but also in the diluted area. The reaction can thus take place as long as possible at high temperature, the risk of sticking being less in the zones where the particles are in agitation and separated from each other.

On peut donc de la sorte régler la température de réaction au niveau le plus élevé possible et en particulier à un niveau permettant l'agglomération des cendres en blocs susceptibles d'être évacués par des moyens connus, sans atteindre cependant la température de fusion qui risquerait d'entraîner un blocage du réacteur.In this way it is therefore possible to adjust the reaction temperature to the highest possible level and in particular to a level allowing the agglomeration of the ash into blocks capable of being removed by known means, without however reaching the melting temperature which would risk cause a blockage of the reactor.

Comme on l'a indiqué, la température de collage dépend des conditions de fonctionnement et par conséquent, ayant observé celles-ci, on pourra déterminer dans chaque zone de l'installation, en fonction des circonstances propres à cette zone, la température limite à ne pas dépasser.As indicated, the bonding temperature depends on the operating conditions and therefore, having observed these, it will be possible to determine in each zone of the installation, according to the circumstances specific to this zone, the temperature limit at not to exceed.

Selon les caractéristiques constructives de chaque installation, on pourra contrôler l'ensemble de celle-ci ou bien certaines zones bien choisies. D'une façon générale les températures seront contrôlées de préférence dans au moins une zone A à la base de la chambre de réaction, c'est-à-dire dans la zone dense du lit fluidisé, une zone B légèrement au-dessus du niveau limite de la zone dense, une zone C dans la zone diluée, à la partie supérieure de la chambre de réaction et une zone D juste en amont du dispositif de récupération.According to the constructive characteristics of each installation, it will be possible to control all of it or else certain well-chosen zones. In general, the temperatures will preferably be controlled in at least one zone A at the base of the reaction chamber, that is to say in the dense zone of the fluidized bed, a zone B slightly above the level limit of the dense zone, a zone C in the diluted zone, at the upper part of the reaction chamber and a zone D just upstream of the recovery device.

Pour réaliser un abaissement local de température dans la zone choisie, on injectera dans celle-ci un produit froid sous forme divisée qui peut être constitué par exemple par de l'eau pulvérisée ou de la vapeur d'eau, par des particules récupérées et refroidies avant d'être recyclées dans le lit fluidisé ou bien par une partie du gaz produit, prélevée à la sortie du dispositif de récupération et recyclée dans la zone voulue après refroidissement. Mais le produit froid injecté peut aussi être constitué par au moins une partie de la matière combustible introduite à la partie supérieure de la zone diluée dans la chambre de réaction avec un débit réglable de telle sorte que les particules les plus grosses tombent dans la zone dense du lit fluidisé en traversant la zone diluée, les particules les plus fines étant entraînées avec les fumées vers le dispositif de récupération puis recyclées dans le lit fluidisé.To achieve a local temperature reduction in the chosen area, a cold product in divided form will be injected into it, which may consist, for example, of water spray or steam, of particles recovered and cooled before being recycled in the fluidized bed or by a part of the gas produced, taken at the outlet of the recovery device and recycled in the desired zone after cooling. However, the cold product injected can also consist of at least part of the combustible material introduced into the upper part of the diluted zone in the reaction chamber with an adjustable flow rate so that the coarsest particles fall into the dense zone. of the fluidized bed while crossing the diluted zone, the particles the finest being entrained with the fumes to the recovery device and then recycled into the fluidized bed.

L'invention couvre également une installation perfectionnée de traitement de matière combustible constituée, de façon classique, par une chambre de réaction verticale munie de moyens d'alimentation en matière combustible solide et, à sa base, de moyens de fluidisation par injection d'un gaz avec un débit reglable et relié à sa partie supérieure, par un conduit de sortie des fumées à un dispositif de récupération des matières solides entraînées, comprenant une sortie supérieure, une sortie inférieure des particules solides reliées par un circuit de recyclage à la base de la chambre de réaction.The invention also covers an improved installation for processing combustible material, conventionally constituted by a vertical reaction chamber provided with means for supplying solid combustible material and, at its base, means for fluidization by injection of a gas with an adjustable flow rate and connected at its upper part, by a flue outlet pipe to a device for recovering entrained solid materials, comprising an upper outlet, a lower outlet for solid particles connected by a recycling circuit to the base of the reaction chamber.

Suivant l'invention l'installation comprend, en amont du dispositif de récupération, une pluralité de zones (A, B, C, D,...) de contrôle de température, échelonnées dans le sens de circulation des gaz et des matières et couvrant chacune toute la section transversale de passage des gaz au niveau considéré, chaque zone de contrôle (A, B, C, D,...) étant munie d'un moyen de mesure de la température ambiante moyenne et d'un moyen de refroidissement provoquant un abaissement localisé de cette température ambiante dans la zone considérée et que les moyens de mesure de température et de refroidissement des zones de contrôle sont associés à un dispositif de régulation comprenant un ensemble de comparateurs des températures mesurées avec des températures de référence déterminées en fonction des conditions de fonctionnement souhaitées dans chaque zone de contrôle (A, B, C, D,...), un ensemble d'organes de réglage des moyens de refroidissement et un moyen de pilotage des organes de réglage en fonction des différences constatées entre les températures mesurées et les températures de référence.According to the invention, the installation comprises, upstream of the recovery device, a plurality of zones (A, B, C, D, ...) of temperature control, staggered in the direction of circulation of the gases and materials and each covering the entire cross section of the gas passage at the level in question, each control zone (A, B, C, D, ...) being provided with a means of measuring the average ambient temperature and a means of cooling causing a localized lowering of this ambient temperature in the zone considered and that the temperature measurement and cooling means of the control zones are associated with a regulation device comprising a set of comparators of the temperatures measured with reference temperatures determined in depending on the desired operating conditions in each control zone (A, B, C, D, ...), a set of adjustment means for the cooling means and a means for controlling the adjustment means in function ction of the differences observed between the measured temperatures and the reference temperatures.

Mais l'invention sera mieux comprise en se référant à un mode de réalisation particulier, donné à titre d'exemple et représenté sur le dessin annexé.However, the invention will be better understood by referring to a particular embodiment, given by way of example and shown in the accompanying drawing.

La figure unique représente schématiquement une installation de gazéification de charbon en lit fluidisé munie des perfectionnements selon l'invention.The single figure schematically represents a gasification plant for coal in a fluidized bed provided with improvements according to the invention.

L'installation de gazéification comprend essentiellement une chambre de réaction 1 en forme de colonne, constituée d'une enceinte cylindrique allongée à axe vertical munie à sa base d'une grille de distribution homogène d'un gaz de fluidisation introduit au-dessous de la grille avec un débit réglable par des moyens d'injection 11. La chambre de réaction 1 est reliée à sa partie supérieure, par une conduite 12 de sortie des fumées, à un dispositif 2 de récupération des particules solides entraînées, par exemple un dépoussiéreur à cyclone comprenant une sortie supérieure 21 des gaz et une sortie inférieure 22 des particules récupérées qui débouche dans une conduite 23 de recyclage reliée à la base de la chambre 1 par un dispositif de réinjection des particules solides constituée par exemple d'un siphon 24 dans lequel peut être injecté en 25 un gaz permettant le réglage du débit de réinjection.The gasification installation essentially comprises a reaction chamber 1 in the form of a column, consisting of an elongated cylindrical enclosure with a vertical axis provided at its base with a grid for the homogeneous distribution of a fluidization gas introduced below the grate with a flow rate adjustable by injection means 11. The reaction chamber 1 is connected at its upper part, by a flue outlet pipe 12, to a device 2 for recovering entrained solid particles, for example a dust collector cyclone comprising an upper outlet 21 for the gases and a lower outlet 22 for the recovered particles which opens into a recycling pipe 23 connected to the base of the chamber 1 by a device for reinjecting solid particles consisting for example of a siphon 24 in which can be injected into a gas allowing adjustment of the reinjection rate.

La matière combustible, stockée dans une trémie 13 est introduite à la base de la chambre de combustion, dans le lit fluidisé, par exemple au moyen d'un dispositif 14 d'alimentation à vis permettant de régler le débit d'alimentation en agissant sur la vitesse de rotation de la vis. De plus, une conduite de purge 18 placée à l'extrémité inférieure de la chambre de combustion 1 permet d'évacuer les cendres agglomérées.The combustible material, stored in a hopper 13 is introduced at the base of the combustion chamber, into the fluidized bed, for example by means of a screw feed device 14 making it possible to adjust the feed rate by acting on the speed of rotation of the screw. In addition, a purge line 18 placed at the lower end of the combustion chamber 1 makes it possible to remove the agglomerated ash.

Bien entendu, l'ensemble de l'installation mais tout particulièrement les parois de la chambre de combustion sont revêtues d'un revêtement réfractaire et isolant.Of course, the entire installation, but especially the walls of the combustion chamber are coated with a refractory and insulating coating.

Le débit de l'organe 11 d'injection de gaz de fluidisation est réglé de telle sorte que l'installation fonctionne en lit circulant, la vitesse de circulation des gaz étant supérieure à 4 m/s de telle sorte que les gaz entraînent la plus grande partie des particules solides qui occupent alors toute la hauteur de la colonne 1 à l'intérieur de laquelle on distingue une zone inférieure 15 en phase dense et une zone supérieure 16 en phase diluée. En pratique, la matière combustible introduite dans la chambre 1 se divise en deux parties: les particules les plus fines sont immédiatement entraînées avec les gaz alors que les particules les plus grosses tombent dans la zone dense 15 et y restent jusqu'au moment où, après combustion partielle, elles atteignent une dimension qui leur permet d'être entraînées à leur tour. La zone dense peut également contenir une matière granulaire inerte servant de support à la fluidisation ou bien ayant un rôle dans la réaction.The flow rate of the fluidizing gas injection member 11 is adjusted so that the installation operates in a circulating bed, the gas circulation speed being greater than 4 m / s so that the gases entrain the most large part of the solid particles which then occupy the entire height of the column 1 inside which there is a lower zone 15 in the dense phase and an upper zone 16 in the diluted phase. In practice, the combustible material introduced into the chamber 1 is divided into two parts: the finer particles are immediately entrained with the gases while the larger particles fall into the dense zone 15 and remain there until, after partial combustion, they reach a dimension which allows them to be trained in turn. The dense zone can also contain an inert granular material serving as a support for fluidization or else having a role in the reaction.

Les particules solides entraînées dans la conduite de sortie 12 sont arrêtées dans le récupérateur 2 puis recyclées dans le lit fluidisé par la conduite 24.The solid particles entrained in the outlet pipe 12 are stopped in the recuperator 2 and then recycled in the fluidized bed through the pipe 24.

On peut distinguer dans l'installation un certain nombre de zones (A, B, C, D,...) échelonnées dans le sens de circulation des gaz et des particules, et pour chacune desquelles il est possible de définir une température optimale qui dépend des conditions de fonctionnement régnant dans la zone considérée.One can distinguish in the installation a certain number of zones (A, B, C, D, ...) staggered in the direction of circulation of gases and particles, and for each of which it is possible to define an optimal temperature which depends on the operating conditions prevailing in the area considered.

Les zones de contrôle (A, B, C, D) sont placées respectivement, d'une part à au moins trois niveaux de la chambre de réaction 1, respectivement en (A) dans la partie dense du lit fluidisé, en (B) à la surface limite de celui-ci et enThe control zones (A, B, C, D) are placed respectively, on the one hand at least at three levels of the reaction chamber 1, respectively in (A) in the dense part of the fluidized bed, in (B) at the boundary surface of it and in

(C) à la sortie de la chambre de réaction, et d'autre part, en (D) dans le séparateur 2.(C) at the outlet of the reaction chamber, and on the other hand, at (D) in the separator 2.

La zone dense du lit fluidisé contient les particules de combustible et de matière inerte les plus grosses et est traversée par les particules fines recyclées constituées de matière incomplètement brûlée et de cendres. Il est souhaitable de maintenir dans cette zone une température pour laquelle les cendres sont suffisamment ramolies pour permettre leur agglomération en évitant cependant leur fusion ou prise en masse. En effet, en s'agglomérant, les cendres forment des blocs plus faciles à éliminer mais une trop forte élévation de température pourrait entraîner la fusion des cendres et leur collage entre elles et sur les parois du réacteur avec risque de blocage ce celui-ci.The dense area of the fluidized bed contains the largest particles of fuel and inert material and is traversed by the recycled fine particles consisting of incompletely burnt material and ash. It is desirable to maintain in this zone a temperature for which the ashes are sufficiently softened to allow their agglomeration, however, avoiding their merger or solidification. In fact, by agglomerating, the ash forms blocks which are easier to remove, but too high a temperature rise could cause the ash to melt and stick together between them and on the walls of the reactor with the risk of blocking it.

Dans la zone diluée 16, les particules solides emportées par le fluide gazeux se trouvent sensiblement à la même température que dans la zone dense 15 et sont donc agglomérantes: leur concentration étant plus faible et leur agitation importante, la tendance à l'agglomération est moindre mais il faut encore éviter le collage des particules sur les parois du reacteur en particulier dans les zones critiques qu'il est possible de localiser.In the diluted zone 16, the solid particles carried away by the gaseous fluid are found at substantially the same temperature as in the dense zone 15 and are therefore agglomerating: their concentration being lower and their agitation significant, the tendency to agglomeration is less but it is also necessary to avoid sticking of the particles on the walls of the reactor, in particular in the critical zones which it is possible to locate.

Ce risque de collage sur les parois est encore plus important dans le séparateur 2 en raison de l'effet de la force centrifuge qui plaque les cendres contre les parois et du fait que les particules solides y sont tassées et pratiquement immobiles les unes par rapport aux autres avant d'être renvoyées vers la chambre de réaction par le circuit 24.This risk of sticking to the walls is even greater in the separator 2 because of the effect of the centrifugal force which presses the ashes against the walls and the fact that the solid particles are packed there and practically immobile with respect to the others before being returned to the reaction chamber by circuit 24.

On peut, par le calcul et, dans une certaine mesure, empiriquement, définir pour chaque zone la température optimale de fonctionnement dont il faut se rapprocher le plus possible pour obtenir une bonne agglomération mais sans la dépasser pour éviter la fusion des cendres. D'autre part, on peut placer un certain nombre de capteurs de température 31, 32, 33, 34 dans les parties les plus sensibles de l'installation. Ainsi, dans l'exemple de réalisation représenté sur la figure, on a placé un capteur 31 dans le centre de la zone dense 15, un capteur 32 à la partie inférieure de la zone diluée 16, légèrement au-dessus du niveau limite de la zone dense, un capteur 33 à l'extrémité supérieure de la chambre de réaction 1, près du carneau de sortie et un capteur 34 à l'entrée du récupérateur 2 près de la paroi.It is possible, by calculation and, to a certain extent, empirically, to define for each zone the optimal operating temperature which must be brought as close as possible to obtain good agglomeration but without exceeding it to avoid the melting of the ashes. On the other hand, a number of temperature sensors 31, 32, 33, 34 can be placed in the most sensitive parts of the installation. Thus, in the embodiment shown in the figure, a sensor 31 was placed in the center of the dense area 15, a sensor 32 at the bottom of the diluted area 16, slightly above the limit level of the dense area, a sensor 33 at the upper end of the reaction chamber 1, near the outlet flue and a sensor 34 at the inlet of the recuperator 2 near the wall.

L'ensemble des capteurs est relié à un dispositif de mesure 3 fournissant à sa sortie des signaux correspondant aux températures mesurées par chacun des capteurs, qui sont appliqués à un ensemble d'organes 41, 42, 43, 44 de comparaison de chaque signal de température avec un signal affiché correspondant à la température de référence déterminée pour la zone considérée.The set of sensors is connected to a measuring device 3 providing at its output signals corresponding to the temperatures measured by each of the sensors, which are applied to a set of members 41, 42, 43, 44 for comparing each signal of temperature with a displayed signal corresponding to the reference temperature determined for the zone considered.

D'autre part, dans chaque zone, on dispose d'un moyen d'intervention localisé permettant de diminuer rapidement la température de la zone considérée dès qu'une élévation excessive de température est détectée. Ce moyen d'intervention est constitué, dans l'exemple représenté, d'un circuit de refroidissement 5 comprenant un ventilateur 51 dont la conduite d'alimentation 52 est branché sur la gaine 26 de sortie des gaz du séparateur 2 pour prélever une partie des gaz évacués, ceux-ci ayant été de préférence refroidis grâce à un échangeur 27 placé sur la gaine de sortie 26 en amont de la conduite d'alimentation 52. La conduite de refoulement 5 du ventilateur 51 se divise en un certain nombre de branches 6 munies à leurs extrémités d'injecteurs 61, 62, 63, 64 débouchant dans les différentes zones de l'installation, sensiblement à la hauteur du capteur de température correspondant. On peut d'ailleurs, en cas de besoin, munir chaque branche d'injection 6 d'une pluralité d'injecteurs répartis régulièrement dans un plan transversal à l'axe de façon que le fluide de refroidissement injecté se répande de façon homogène dans toute la section transversale de l'installation à la hauteur de la zone considérée. Les organes 61 62, 63, 64 permettent d'injecter dans l'ensemble de la zone un produit sous forme divisée et à une température inférieure à la température mesurée dans la zone de contrôle. Etant donné l'effet d'homogénéisation des températures obtenues en outre par l'utilisation d'une vitesse de fluidisation élevée, on pourra ainsi contrôler la température de façon assez précise à l'intérieur de chaque zone de l'installation, sur l'ensemble de la section transversale de passage des gaz.On the other hand, in each zone, there is a localized intervention means making it possible to rapidly decrease the temperature of the zone considered as soon as an excessive rise in temperature is detected. This intervention means consists, in the example shown, of a cooling circuit 5 comprising a fan 51, the supply line 52 of which is connected to the sheath 26 of the gas outlet from the separator 2 in order to take off part of the evacuated gases, these having preferably been cooled by means of an exchanger 27 placed on the outlet sheath 26 upstream of the supply line 52. The discharge line 5 of the fan 51 is divided into a number of branches 6 provided at their ends with injectors 61, 62, 63, 64 opening into the various zones of the installation, substantially at the height of the corresponding temperature sensor. It is also possible, if necessary, to provide each injection branch 6 with a plurality of injectors distributed regularly in a plane transverse to the axis so that the injected cooling fluid is spread evenly throughout the cross section of the installation at the height of the area considered. The members 61 62, 63, 64 make it possible to inject a product in divided form throughout the zone and at a temperature below the temperature measured in the control zone. Given the homogenizing effect of the temperatures obtained in addition by the use of a high fluidization speed, it will thus be possible to control the temperature fairly precisely inside each zone of the installation, on the entire cross section of the gas passage.

A cet effet, chaque branche 6 du circuit de refroidissement sera muni d'une vanne 71, 72, 73, 74 pilotée par un calculateur 7 en fonction des différences de températures mesurées par les comparateurs 41, 42, 43, 44. Bien entendu, le calculateur 7 est programmé de façon à tenir compte des interactions entre les zones, tout refroidissement dans une zone ayant des répercussions dans les zones suivantes. On dispose ainsi d'un moyen souple et précis de contrôle de la température dans les différentes zones de l'installation permettant d'éviter une surchauffe localisée avec fusion des cendres et risque de collage sur les parois, en tenant compte des conditions de fonctionnement propres à chaque zone et notamment de la section de passage des gaz, de la granulométrie et de la densité des particules solides. En cas de besoin, on pourrait évidemment augmenter le nombre de zones de contrôle et notamment placer plusieurs détecteurs de température et plusieurs injecteurs de fluide froid échelonnés sur toute la hauteur de la zone diluée 16 de la colonne 1.To this end, each branch 6 of the cooling circuit will be provided with a valve 71, 72, 73, 74 controlled by a computer 7 as a function of the temperature differences measured by the comparators 41, 42, 43, 44. Of course, the computer 7 is programmed to take account of the interactions between the zones, any cooling in one zone having repercussions in the following zones. There is thus a flexible and precise means of controlling the temperature in the various zones of the installation, making it possible to avoid localized overheating with melting of the ashes and risk of sticking to the walls, taking account of the proper operating conditions. to each zone and in particular of the gas passage section, the particle size and the density of the solid particles. If necessary, one could obviously increase the number of control zones and in particular place several temperature detectors and several cold fluid injectors staggered over the entire height of the diluted zone 16 of column 1.

Dans l'exemple représenté, le contrôle de température des différentes zones est obtenu par injection d'une partie des fumées prélevées à la sortie du séparateur, après refroidissement à une température inférieure à la température ambiante dans les différentes zones de l'installation. On pourrait cependant injecter un autre agent refroidissant fluide tel que de la vapeur d'eau ou de l'eau pulvérisée en tenant compte évidemment de l'influence d'une telle injection sur le bilan thermique. Mais on peut aussi injecter des particules solides finement pulvérisées de façon à se répandre rapidement dans la zone de contrôle. C'est le cas, en particulier, des particules solides retenues par le séparateur 2 et recyclées dans le lit fluidisé par le circuit 23. Celui-ci pourrait être muni par exemple d'un échangeur 28 permettant de ramener la température des particules recyclées au niveau souhaité. Dans ce cas, on agit directement sur la température existant dans le lit fluidisé, les particules recyclées étant immédiatement réparties dans la zone 15 par l'effet de turbulence produit par la fluidisation mais, on peut aussi prélever un certain débit de particules sur la conduite de recyclage 23, en aval de l'échangeur 28, pour les réintroduire par des moyens appropriés dans d'autres zones de l'installation.In the example shown, the temperature control of the different zones is obtained by injecting a portion of the fumes sampled at the outlet of the separator, after cooling to a temperature below ambient temperature in the different zones of the installation. One could however inject another fluid cooling agent such as water vapor or water spray, obviously taking into account the influence of such an injection on the thermal balance. However, it is also possible to inject finely pulverized solid particles so as to spread quickly in the control zone. This is the case, in particular, of the solid particles retained by the separator 2 and recycled into the fluidized bed by the circuit 23. The latter could for example be provided with an exchanger 28 making it possible to bring the temperature of the recycled particles at the desired level. In this case, one acts directly on the temperature existing in the fluidized bed, the recycled particles being immediately distributed in the zone 15 by the turbulence effect produced by the fluidization but, one can also take a certain flow of particles on the pipe. recycling 23, downstream of the exchanger 28, to reintroduce them by appropriate means in other areas of the installation.

Le système qui vient d'être décrit permet donc de contrôler les températures dans l'ensemble de l'installation et la nature du produit refroidissant injecté pourra être déterminée en fonction de la zone sur laquelle on souhaite agir et de l'effet souhaité.The system which has just been described therefore makes it possible to control the temperatures throughout the installation and the nature of the injected cooling product can be determined as a function of the zone on which it is desired to act and of the desired effect.

Ainsi, dans le bas ou dans le centre de la zone 15 du lit fluidisé, on injectera de préférence des particules solides ou de l'eau en phase gazeuse ou liquide pour contrôler l'agglomération.Thus, at the bottom or in the center of zone 15 of the fluidized bed, solid particles or water are preferably injected in the gas or liquid phase to control agglomeration.

A la hauteur de la surface de séparation de la zone dense et de la zone diluée, pour éviter le collage des cendres sur les parois, on injectera, en 62 des particules recyclées, de l'eau ou une partie des fumées prélevées après refroidissement et recyclées par le circuit 5.At the height of the separation surface of the dense zone and the diluted zone, in order to avoid sticking of the ashes on the walls, we will inject, at 62, recycled particles, water or part of the fumes collected after cooling and recycled by circuit 5.

A la sortie de la zone dense 16, dans la conduite de liaison 12 ou à l'entrée du séparateur 2, on injectera de l'eau ou du gaz recyclé, par les injecteurs 63 ou 64, pour éviter les collages et les accumulations dans le séparateur. Pour modifier la température dans le sens souhaité, on pourra évidemment utiliser les injections isolément ou en combinaison entre-elles, en agissant soit sur le débit injecté si l'agent refroidissant est un gaz ou de l'eau pulvérisée, soit, de préférence, sur la température si l'agent refroidissant est constitué de particules solides recyclées.At the exit from the dense zone 16, in the connection line 12 or at the entrance to the separator 2, water or recycled gas will be injected, via the injectors 63 or 64, to avoid sticking and accumulation in the separator. To modify the temperature in the desired direction, it is obviously possible to use the injections individually or in combination with one another, by acting either on the flow rate injected if the cooling agent is a gas or water spray, or, preferably, on the temperature if the coolant consists of recycled solid particles.

Dans un mode de réalisation particulier, on peut aussi utiliser comme produit de refroidissement une partie du combustible prélevé sur le circuit d'alimentation de celui-ci et injecté en 17, de préférence à la partie supérieure de la zone diluée 16.In a particular embodiment, part of the fuel taken from the feed circuit thereof and injected at 17, preferably at the top of the diluted zone 16, can also be used as a cooling product.

Les grosses particules tombent directement dans la zone dense 15 et les fines sont emportées directement vers le séparateur 2 par la conduite de sortie 12. Cette introduction de combustible froid dans la zone diluée 16 qui se trouve au-dessous de la stoechiométrié provoque donc un abaissement de température dans la zone d'injection non seulement du fait de l'introduction d'un produit froid mais également par l'effet de la réaction endothermique d'élimination des matières volatiles contenues dans le charbon au contact des gaz chauds. De la sorte, en plus du refroidissement on obtient un effet secondaire de dégazage du carbon qui permet de diminuer le risque d'agglomération. Ce pré-traitement peut être utile pour certains charbons agglomérants difficiles à traiter dans un lit fluidisé. En outre, on augmente ainsi la teneur en méthane du gaz produit et par conséquent son pouvoir calorifique ce qui est intéressant lorsque le gaz produit est utilisé comme combustible.The large particles fall directly into the dense zone 15 and the fines are carried directly to the separator 2 via the outlet line 12. This introduction of cold fuel into the diluted zone 16 which is below the stoichiometry therefore causes a lowering of temperature in the injection zone not only due to the introduction of a cold product but also by the effect of the endothermic reaction of elimination of the volatile materials contained in the coal in contact with the hot gases. In this way, in addition to cooling, a secondary degassing effect of carbon is obtained which makes it possible to reduce the risk of agglomeration. This pre-treatment can be useful for certain agglomerating coals which are difficult to treat in a fluidized bed. In addition, this increases the methane content of the gas produced and therefore its calorific value which is advantageous when the gas produced is used as fuel.

Bien entendu, l'installation selon l'invention n'a été décrite que schématiquement, les dispositifs utilisés tels que le système de régulation et les moyens de refroidissement et d'injection du produit recyclé pouvant être réalisés avec des moyens connus. D'une façon générale, l'invention pourrait faire l'objet de variantes et de perfectionnements, et, par exemple, on pourrait diviser la chambre de réaction en un plus grand nombre de zones de contrôle de température échelonnées de bas en haut à l'intérieur de la zone dense et surtout dans la zone diluée du lit fluidisé.Of course, the installation according to the invention has only been described schematically, the devices used such as the regulation system and the means for cooling and injecting the recycled product being able to be produced with known means. In general, the invention could be the subject of variants and improvements, and, for example, the reaction chamber could be divided into a greater number of temperature control zones staggered from bottom to top to 1 inside the dense zone and especially in the diluted zone of the fluidized bed.

Claims (13)

1. Process for a fluidized bed treatment of a fuel in a plant comprising a vertical reaction chamber (1) provided at its base with means (14) for feeding fuel and means (11) for fluidizing by injecting a gas and whose upper end is connected by a gas exit duct (12) to a device (2) for recovering the entrained solid particles comprising an exit orifice (21) for the gases and an exit orifice (22) for the solid particles which are connected by a recycling circuit (23) to the base of the reaction chamber (1), characterized in that, with the nature of the fuel and the operating conditions, such as the shape and the dimensions of the plant, the particle size measurements of the particles and the gas circulation velocities, being taken into account:
- a reference temperature is determined, above which the stationary solid particles are liable to adhere to each other inside the recovery device
(2),
- the fluidization conditions are adjusted to produce a circulating bed regime in the plant,
- the reaction temperature in the dense part (15) of the fluidized bed is adjusted to a level above the reference temperature,
- the average temperatures are measured in a plurality of temperature control zones (A, B, C, D, etc) placed at intervals in the direction of travel of the gases and of the solids inside the plant,
- each measured temperature is compared with the determined reference temperature, and
- a lowering of the average temperature is produced locally in any one zone, upstream of the recovery device (2) each time the temperature measured therein reaches the reference temperature, in order to keep the average temperature in each zone continually below the corresponding reference temperature.
2. Treatment process according to Claim 1, characterized in that the reaction temperature in the dense part (15) of the fluidized bed is adjusted at a level which permits ash to agglomerate into blocks capable of being discharged.
3. Treatment process according to Claim 1, characterized in that the measurement of the average temperatures in the zones (A, B, C, D, etc) is made so as to control the temperatures in at least one zone (A) at the base of the reaction chamber (1) in the dense zone of the fluidized bed, a zone (B) slightly above the level limiting chamber (1) and a zone (D) just upstream of the recovery device (2).
4. Treatment process according to one of the preceding claims, characterized in that the local lowering of temperature is produced by injecting a cold substance in a divided form into the zone in question.
5. Treatment process according to Claim 4, characterized in that the cold substance injected consists of finely sprayed water or of steam.
6. Treatment process according to Claim 4, characterized in that the cold substance injected consists of particles recovered at the exit of the recovery device (2) and recycled into the fluidized bed after cooling.
7. Treatment process according to Claim 4, characterized in that the cold substance injected consists of a part of the gas produced, abstracted at the exit of the recovery device (2) and recycled, after cooling, into the desired zone.
7. Treatment process according to Claim 4, characterized in that the cold substance injected consists of at least a part of the fuel introduced into the upper part of the dilute zone (16) of the reaction chamber (1), at a flow rate which can be regulated, with the largest particles falling into the dense zone (15) of the fluidized bed by passing through the dilute zone (16) and with the finest particles being entrained with the fumes towards the recovery device (2) and then being recycled into the fluidized bed (15).
9. Plant for treating a fuel, comprising a vertical reaction chamber (1) provided with means (14) for feeding solid fuel and, at its base, means (11) for fluidizing by injecting a gas at a flow rate which can be regulated and connected, in its upper part, by a fume exit duct (12) to a device (2) for recovering the solid matter entrained, comprising an upper exit (21), and a lower exit (22) for the solid particles which are connected by a recycle circuit (23) to the base of the reaction chamber (1), characterized in that it comprises, upstream of the recovery device (2), a plurality of temperature control zones (A, B, C, D, etc) placed at intervals in the direction of travel of the gases and of the solids and each covering the entire gas flow cross-section at the level in question, each control zone (A, B, C, D, etc) being provided with a means (31, 32, 33, 34) for measuring the average ambient temperature and with a means (61, 62, 63, 64) for cooling causing a localized lowering of this ambient temperature in the zone in question and in that the means for measuring temperature (31, 32, 33, 34) and for cooling (61, 62, 63, 64) of the control zones are associated with a regulating device comprising a set of comparators (41) of the measured temperatures with the determined reference temperatures as a function of the desired operating conditions in each control zone (A, B, C, D, etc), a set of instruments for regulating the means of cooling (61, 62, 63, 64) and a means (7) for controlling the regulating instruments as a function of the differences found between the measured temperatures and the reference temperatures.
10. Plant according to Claim 9, characterized in that the control zones (A, B, C, D) are placed respectively, on the one hand, at at least three levels of the combustion chamber at (A) in the dense part of the fluidized bed, at (B) at the surface limiting the latter, and at (C) at the outlet of the combustion chamber, respectively, and, on the other hand, at (D) in the separating device (2).
11. Treatment plant according to Claim 9, characterized in that the means for localized cooling consist, for each control zone (A, B, C, D), of an instrument (61, 62, 63, 64) for injecting into the whole zone a substance in divided form which is at a temperature below the temperature measured in the control zone.
12. Treatment plant according to Claims 9 and 10, characterized in that the means of cooling comprise an instrument (27) for cooling the fumes leaving the separator (2) and a circuit (5) for abstracting a part of the fumes after cooling comprising several branches (6) opening, respectively, into the zone in question of the plant, by means of an injector (61, 62, 63, 64) and each being provided with an instrument (71, 72, 73, 74) for regulating the reinjected flow rate, controlled by a regulating device (7) as a function of the temperatures measured in the zone in question.
13. Treatment plant according to one of Claims 9 to 12, characterized in that each control zone (A, B, C, D) covers the whole flow cross-section of the gases at the location in question in the plant.
EP84400961A 1983-05-17 1984-05-11 Process and apparatus for the treatment of fuel in a fluidized bed Expired EP0126001B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84400961T ATE32606T1 (en) 1983-05-17 1984-05-11 METHOD AND DEVICE FOR TREATMENT OF A FUEL IN A FLUIDIZED BED.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8308166 1983-05-17
FR8308166A FR2546177B1 (en) 1983-05-17 1983-05-17 IMPROVED PROCESS AND INSTALLATION FOR TREATING A FUEL MATERIAL IN A FLUIDIZED BED

Publications (2)

Publication Number Publication Date
EP0126001A1 EP0126001A1 (en) 1984-11-21
EP0126001B1 true EP0126001B1 (en) 1988-02-24

Family

ID=9288925

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84400961A Expired EP0126001B1 (en) 1983-05-17 1984-05-11 Process and apparatus for the treatment of fuel in a fluidized bed

Country Status (8)

Country Link
EP (1) EP0126001B1 (en)
AT (1) ATE32606T1 (en)
BR (1) BR8402303A (en)
CA (1) CA1270699A (en)
DE (1) DE3469442D1 (en)
FR (1) FR2546177B1 (en)
IN (1) IN161204B (en)
ZA (1) ZA843725B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI86105C (en) * 1985-11-19 1992-07-10 Ahlstroem Oy FOERFARANDE OCH ANORDNING FOER REGLERING AV EN VIRVELBAEDDSREAKTORS FUNKTION.
DE3580488D1 (en) * 1985-12-09 1990-12-13 Ahlstroem Oy REACTOR WITH CIRCULATING FLUID BED, METHOD FOR SEPARATING SOLIDS FROM SMOKE GAS.
US4763585A (en) * 1987-09-08 1988-08-16 Ogden Environmental Services Method for the combustion of spent potlinings from the manufacture of aluminum

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1074803B (en) * 1960-02-04 Badische Anilin- &. Soda-Fabrik Aktiengesellschaft, Ludwigshafen/Rhein Process for generating fuel gas by gasifying finely divided solid or liquid fuels and / or by splitting gaseous fuels in a fluidized bed
DE919004C (en) * 1951-11-10 1954-10-11 Basf Ag Method and device for gasifying solid fuels
US4158552A (en) * 1977-08-29 1979-06-19 Combustion Engineering, Inc. Entrained flow coal gasifier
GB2027444B (en) * 1978-07-28 1983-03-02 Exxon Research Engineering Co Gasification of ash-containing solid fuels
DE2925441C2 (en) * 1979-06-23 1982-10-14 Carbon Gas Technologie GmbH, 4030 Ratingen Method and device for gasifying coal in a fluidized bed
JPS5776088A (en) * 1980-10-31 1982-05-12 Nippon Kokan Kk <Nkk> Coal gasification using powdered coal and its device

Also Published As

Publication number Publication date
CA1270699A (en) 1990-06-26
BR8402303A (en) 1984-12-26
IN161204B (en) 1987-10-17
ATE32606T1 (en) 1988-03-15
FR2546177A1 (en) 1984-11-23
ZA843725B (en) 1984-12-24
FR2546177B1 (en) 1987-07-17
DE3469442D1 (en) 1988-03-31
EP0126001A1 (en) 1984-11-21

Similar Documents

Publication Publication Date Title
EP0161970B1 (en) Method and installation for the treatment of material in a circulating fluidized bed
EP0093063B1 (en) Process and device for controlling the temperature of a reaction carried out in a fluidized bed
FR2470152A1 (en) PROCESS FOR GASIFYING CARBON MATERIALS
EP2758711B1 (en) Chemical looping combustion method with removal of ash and fines in the reduction area, and a facility using such a method
EP0084492B1 (en) Furnace and process for treating solid fuel particles in a fluidized bed
EP0162748B1 (en) Process and apparatus for bringing solid particles into circulation within a fluidisation chamber
EP0173782B1 (en) Process for treating materials
EP0156703A1 (en) Method and device for controlling heat transfer in a fluidized bed
FR2554107A1 (en) PROCESS AND APPARATUS FOR THE CALCINATION OF MINERAL MATERIALS REDUCED IN POWDER
EP0065436A1 (en) Process and installation for the production of a cement-clinker by the dry method
EP0126001B1 (en) Process and apparatus for the treatment of fuel in a fluidized bed
FR2463893A1 (en) METHOD AND APPARATUS FOR SELF-MAINTAINING INCINERATION OF EASILY FRIABLE COMBUSTIBLE AGGLOMERES WITH HIGH WATER CONTENT
FR2586941A1 (en) DEVICE FOR TREATING SOLID MATERIALS IN THE FORM OF PARTICLES, IN A FLUIDIZED FLOWING BED, IN PARTICULAR GASIFICATION DEVICE
FR2485178A1 (en) IMPROVEMENTS IN DEVICES FOR REACTING, SUCH AS COMBUSTION, BETWEEN A SOLID AND A GAS
EP0049677A2 (en) Device for the transformation of ligneous waste materials, particularly of wood waste, into combustible granules of small diameters, and granules obtained with this device
EP0148799B1 (en) Process for the gasification of coal and slams
FR2593891A1 (en) COMBUSTION PLANT HAVING A REACTION CHAMBER FOR A CIRCULATING FLUIDIZED BED
EP0308300B1 (en) Combustion process in a fluidised bed and installation for carrying out the process
EP0050579B1 (en) Process and apparatus for producing cold and clean combustible gases by means of a gasification installation for solid combustibles
EP0140763B1 (en) Installation for the treatmet of fuel material, and its operating mode
EP0037782B1 (en) Process for the modification of the properties of swelling coal, system for carrying out the process and vessel for treatment by fluidizing and grinding
EP0995067A1 (en) Method and installation for producing heat, in a reactor with fluidised bed, by combustion of fuels with low calorific value
FR3103027A1 (en) Method of regulating a combustion installation, as well as the corresponding combustion installation
FR2474525A1 (en) Gasification chamber for semi-pulverised solid fuels - provides combustible gases, esp. from coal, which are fed to furnaces etc. previously using gas or liq. fuels
BE511497A (en)

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

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

17P Request for examination filed

Effective date: 19850204

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

REF Corresponds to:

Ref document number: 32606

Country of ref document: AT

Date of ref document: 19880315

Kind code of ref document: T

ITF It: translation for a ep patent filed
GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
REF Corresponds to:

Ref document number: 3469442

Country of ref document: DE

Date of ref document: 19880331

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

Ref country code: LU

Payment date: 19910208

Year of fee payment: 8

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

Ref country code: DE

Payment date: 19910227

Year of fee payment: 8

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

Ref country code: GB

Payment date: 19910424

Year of fee payment: 8

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

Ref country code: AT

Payment date: 19910517

Year of fee payment: 8

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

Ref country code: SE

Payment date: 19910521

Year of fee payment: 8

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

Ref country code: CH

Payment date: 19910523

Year of fee payment: 8

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

Ref country code: FR

Payment date: 19910530

Year of fee payment: 8

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19910531

Year of fee payment: 8

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

Ref country code: BE

Payment date: 19910605

Year of fee payment: 8

EPTA Lu: last paid annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

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

Effective date: 19920511

Ref country code: GB

Effective date: 19920511

Ref country code: AT

Effective date: 19920511

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

Ref country code: SE

Effective date: 19920512

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

Ref country code: LI

Effective date: 19920531

Ref country code: CH

Effective date: 19920531

Ref country code: BE

Effective date: 19920531

BERE Be: lapsed

Owner name: CREUSOT-LOIRE

Effective date: 19920531

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

Ref country code: NL

Effective date: 19921201

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

Effective date: 19920511

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19930129

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

Ref country code: DE

Effective date: 19930202

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EUG Se: european patent has lapsed

Ref document number: 84400961.3

Effective date: 19921204