EP0022549B1 - Process and apparatus for the injection of solid fuel into a shaft furnace - Google Patents

Process and apparatus for the injection of solid fuel into a shaft furnace Download PDF

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Publication number
EP0022549B1
EP0022549B1 EP80103904A EP80103904A EP0022549B1 EP 0022549 B1 EP0022549 B1 EP 0022549B1 EP 80103904 A EP80103904 A EP 80103904A EP 80103904 A EP80103904 A EP 80103904A EP 0022549 B1 EP0022549 B1 EP 0022549B1
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EP
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Prior art keywords
injection
hot air
installation
nozzles
furnace
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EP80103904A
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German (de)
French (fr)
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EP0022549A1 (en
Inventor
Léon Ulveling
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Paul Wurth SA
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Paul Wurth SA
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Priority to AT80103904T priority Critical patent/ATE7515T1/en
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B5/00—Making pig-iron in the blast furnace
    • C21B5/001—Injecting additional fuel or reducing agents
    • C21B5/003—Injection of pulverulent coal

Definitions

  • the present invention relates to a process for injecting solid fuels into a shaft furnace, in particular into a blast furnace, as well as an installation for carrying out this process.
  • a blast furnace is generally provided with a circular duct connected to the base of the furnace by a lining of wind carrier and hot wind injection nozzles which is produced in an installation comprising a blower, a battery of cowpers and a station of mixture having two inlets connected respectively to the blower and to each of the cowpers and an outlet supplying the circular pipe with hot wind at a constant and regulated temperature.
  • the hot wind is generally enriched by means of a fuel which is injected into this hot wind at the level of the nozzles.
  • liquid fuels and more particularly petroleum products, have been used, so to speak. Indeed, these liquid fuels have the advantage of being very easy to handle and the means used for their injection into the nozzles are simple, inexpensive and practically do not disturb the operation of other organs or installations, in particular the temperature of the hot wind into which they are injected.
  • US-A-1,535,174 describes a process for injecting solid fuel into the nozzles of a blast furnace, according to which the fuel is transported using pressurized air.
  • the air used is drawn from the wind supply line to the nozzles and in order to transport the fuel, it is compressed using a fan.
  • US-A-3,197,304 also describes a process for injecting solid fuel into the nozzles of a blast furnace, in which a proportioned portion of the air supplying the nozzles is drawn off and sent to a compressor and then in a heat exchanger. The air then reaches a dryer where it fluidizes the fuel particles and entrains them into the nozzles.
  • the latter can be supplied with fuel separately or a supply can be common to several nozzles.
  • the temperature of the propelling air cannot exceed 80 to 120 ° C.
  • the temperature of the propelling air cannot exceed 80 to 120 ° C.
  • the objective of the present invention is to provide a new method for injecting solid fuels into a shaft furnace which makes it possible to avoid the abovementioned drawbacks, that is to say not to influence the parameters d injection of hot wind.
  • a complementary objective of the invention is the production of an installation for the implementation of this process.
  • a process for injecting solid fuels into a tank furnace provided with a circular pipe connected to the base of the furnace by a lining of wind-carrier and hot-air injection nozzles this hot wind being produced in an installation comprising a blower, a battery of cowpers and a mixing station having two inlets connected respectively to each of the cowpers as well as to the blower by means of an automatic metering device which allows passage in the mixing station the metered quantity of cold wind necessary for stabilizing the temperature of the hot wind which is sent to the circular pipe so that the hot wind circulating in it is at a regulated and constant temperature, and according to which metered quantities of solid fuels in powder form are injected into the hot wind before it enters the furnace, the transport and injection of this solid fuel being real pneumatically driven, characterized in that the pneumatic propulsion fluid used for transporting and injecting the fuel in the hot wind consists of at least one part of the said metered amount of cold wind which is drawn between the metering device and the mixing station and which
  • the installation for implementing this process is essentially characterized in that the pneumatic fuel injection circuit is arranged parallel to the circuit for supplying the circular pipe with hot wind and connected between a point located in the pipe d cold air supply to the mixing station, on the one hand and each of the nozzles on the other hand and comprising a compressor and at least one solid fuel intake device.
  • the fuel intake device preferably consists of a series of airlock airlocks, the number of which can be equal to half the number of nozzles so that an airlock is associated with a pair of nozzles.
  • FIG. 1 schematically shows a blast furnace 2 provided with a circular pipe 4 for supplying hot wind.
  • This circular pipe 4 is connected to the base of the furnace by means of a series of air carriers 6 connected to nozzles not shown embedded in the wall of the furnace.
  • the hot wind for supplying the circular pipe 4 and the wind carriers 6 is produced in an installation 8 essentially comprising a battery of cowpers 12, 14 well known per se.
  • cowpers are, in fact, ovens intended to heat the cold air coming from a blower 10 to a temperature higher than that of the hot wind injected into the oven.
  • the operation of such a cowper comprises two phases, namely a phase of warming and storage of heat and a phase of removal of the stored heat and warming of the cold air. Therefore, to ensure continuous operation, at least one pair of alternating cowpers is required.
  • the designation "cold" of the air sent by the blower 10 into the cowpers 12 and 14 is not significant, since the temperature of this "cold” air is approximately 100 to 120 ° C due to the heating in the blower 10.
  • the temperature of the hot air leaving the cowpers depends on the thermal requirements for injection into the oven. When the hot air injected into the oven must have a temperature of approximately 1200 ° C, the heating produced in the cowpers 12, 14 must rise to approximately 1300 ° C to compensate for the heat losses and to be able to ensure a constant temperature in a station. mixing 16.
  • this mixing station 16 The purpose of this mixing station 16 is to ensure a constant temperature of the hot wind for injection into the oven. Indeed, it is not possible to have a constant and uniform temperature at the exit of the cowpers where there are always fluctuations of a few tens of degrees. This is the reason why it is necessary to heat the hot wind in the cowpers to a sufficient temperature in order to be able to reduce it to a uniform temperature in the mixing station 16 by admitting a metered amount of cold wind through a pipe. 17 connected to the blower 10. The necessary quantity of cold air admitted into the mixing station 16 through the line 17 is automatically adjusted by means of an automatic valve 20 which regulates the flow of cold air as a function of the temperature hot wind in the circular pipe. In this way, it is ensured that the temperature of the hot wind injected into the oven remains constant.
  • This installation 8 for producing hot wind as shown in the figure constitutes a conventional installation well known per se.
  • a parallel circuit 22 is grafted onto this installation 8 for the pneumatic injection of solid fuels into each of the furnace nozzles.
  • a pipe 24 connected to the cold air intake pipe of the mixing station 16 between the latter and the valve 20 and intended to extract the quantity of air necessary for the pneumatic propulsion of the solid fuel. The adjustment of the amount of propelled air deflected in line 24 is automatically adjusted by a valve 26 as required.
  • a compressor 28 intended to raise the pressure of the propelling air in circuit 22 so as to compensate for the pressure losses and ensure injection into the furnace.
  • the pressure difference ⁇ P produced in the compressor 28 is generally 2 bars, counting approximately 1 bar for the compensation of the pressure losses and a reserve of one bar for the injection. Consequently, if the pressure of the hot wind to be injected into the furnace is approximately 2.5 bars, the pressure of the propelling air downstream from the compressors 28 is approximately 4.5 bars.
  • the propulsion air undergoes heating in the compressor 28.
  • the temperature of the propelling air In order to prevent the temperature of the propelling air from reaching the self-ignition threshold of the solid fuel and, also, to reduce the temperature at a value approximately equal to the temperature at the place where the propelling air is drawn off, that is to say between the valve 20 and the station 16, it is preferable to provide a device downstream of the compressor 28 cooling 33.
  • the activity of this cooler 33 can be controlled automatically as a function of the heating in the compressor 28. In this way, if the temperature of the cold air circulating in the pipe 17 is approximately 120 ° C. so that the temperature of the propelling air in line 32, in particular at the time of injection into the oven is also around 120 °.
  • the integration of the circuit 22 into the circuit 8 for producing hot wind does not in any way disturb the operation of the latter and in particular the temperature of the hot wind injected into the oven.
  • the quantity of cold air required by the mixing station 16 for maintaining a constant temperature of the hot wind is determined by the valve 20 and this quantity will always pass through it. The difference is that part of the air delivered by the valve 20 is no longer sent to the mixing station 16, but through the circuit 22 so that the total amount of cold air mixed with the hot wind produced by the cowpers don't change. Part of the mixing, instead of being carried out in the mixing station 16, is now carried out at the level of the injection of the fuel into the wind carriers or into the nozzles.
  • a valve 34 is provided allowing the admission of atmospheric air in circuit 22.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture Of Iron (AREA)
  • Feeding And Controlling Fuel (AREA)
  • Blast Furnaces (AREA)

Description

La présente invention concerne un procédé d'injection de combustibles solides dans un four à cuve, notamment dans un haut fourneau, ainsi qu'une installation pour la mise en oeuvre de ce procédé.The present invention relates to a process for injecting solid fuels into a shaft furnace, in particular into a blast furnace, as well as an installation for carrying out this process.

Un haut fourneau est généralement pourvu d'une conduite circulaire reliée à la base du four par une garniture de porte-vent et de tuyères d'injection de vent chaud qui est produit dans une installation comprenant une soufflante, une batterie de cowpers et une station de mélange ayant deux entrées reliées respectivement à la soufflante et à chacun des cowpers et une sortie alimentant la conduite circulaire en vent chaud à température réglée et constante.A blast furnace is generally provided with a circular duct connected to the base of the furnace by a lining of wind carrier and hot wind injection nozzles which is produced in an installation comprising a blower, a battery of cowpers and a station of mixture having two inlets connected respectively to the blower and to each of the cowpers and an outlet supplying the circular pipe with hot wind at a constant and regulated temperature.

En vue de l'entretien du processus de réduction dans le haut fourneau, le vent chaud est généralement enrichi au moyen d'un combustible que l'on injecte dans ce vent chaud au niveau des tuyères. Jusqu'à présent on a utilisé pour ainsi dire exclusivement des combustibles liquides et plus particulièrement des produits pétroliers. En effet, ces combustibles liquides ont l'avantage d'être très facilement manipulables et les moyens mis en oeuvre pour leur injection dans les tuyères sont simples, peu coûteux et ne perturbent pratiquement pas le fonctionnement d'autres organes ou installations, notamment la température du vent chaud dans lequel ils sont injectés.In order to maintain the reduction process in the blast furnace, the hot wind is generally enriched by means of a fuel which is injected into this hot wind at the level of the nozzles. Until now, liquid fuels, and more particularly petroleum products, have been used, so to speak. Indeed, these liquid fuels have the advantage of being very easy to handle and the means used for their injection into the nozzles are simple, inexpensive and practically do not disturb the operation of other organs or installations, in particular the temperature of the hot wind into which they are injected.

Toutefois, la hausse croissante du prix des produits pétroliers, ainsi que l'épuisement progressif des réserves, ont ouvert la course au remplacement de ces produits par d'autres combustibles, notamment du charbon ou de la lignite. Il est connu que ces combustibles solides pourraient rendre les mêmes services que les combustibles liquides en ce que concerne l'entretien du processus de réduction dans le haut fourneau.However, the increasing rise in the price of petroleum products, as well as the progressive exhaustion of reserves, opened the race to the replacement of these products by other fuels, in particular coal or lignite. It is known that these solid fuels could render the same services as liquid fuels with regard to the maintenance of the reduction process in the blast furnace.

Le brevet US-A-1 535 174 décrit un procédé d'injection de combustible solide dans les tuyères d'un haut fourneau, selon lequel le combustible est transporté à l'aide d'air sous pression. L'air utilisé est soutiré de la conduite d'amenée de vent aux tuyères et afin d'assurer le transport du combustible, il est comprimé à l'aide d'un ventilateur.US-A-1,535,174 describes a process for injecting solid fuel into the nozzles of a blast furnace, according to which the fuel is transported using pressurized air. The air used is drawn from the wind supply line to the nozzles and in order to transport the fuel, it is compressed using a fan.

Le brevet US-A-3 197 304 décrit également un procédé d'injection de combustible solide dans les tuyères d'un haut fourneau, selon lequel une partie dosée de l'air d'alimentation des tuyères est soutirée et envoyée dans un compresseur puis dans un échangeur de chaleur. L'air parvient ensuite dans un sécheur où il effectue une fluidisation des particules de combustible et entraîne ces dernières dans les tuyères. Ces dernières peuvent être alimentées séparément en combustible ou une alimentation peut être commune à plusieurs tuyères.US-A-3,197,304 also describes a process for injecting solid fuel into the nozzles of a blast furnace, in which a proportioned portion of the air supplying the nozzles is drawn off and sent to a compressor and then in a heat exchanger. The air then reaches a dryer where it fluidizes the fuel particles and entrains them into the nozzles. The latter can be supplied with fuel separately or a supply can be common to several nozzles.

Cependant, il subsiste toujours un problème au niveau de l'injection des combustibles solides dans le courant de vent chaud dans les tuyères. En effet, pour la maîtrise parfaite de l'opération du four, il est nécessaire quela température du vent chaud soit constante ou, du moins, qu'elle soit contrôlable. A cet effet, on a prévu en amont de la conduite circulaire une station de mélange dans laquelle on mélange au vent chaud produit dans les cowpers et dont la température est susceptible de fluctuations dans le temps, une certaine quantité d'air froid pour éliminer ces pointes de fluctuations et réduire la température du vent chaud injecté dans le four à une valeur constante. Si l'on utilise la voie pneumatique pour l'injection de combustibles solides dans les fours, il faut envisager des quantités relativement importantes de fluides de propulsion, qui est généralement de l'air. Or, pour éviter un auto- allumage du combustible solide dans les conduites de transport pneumatiques, la température de l'air de propulsion ne peut pas dépasser 80 à 120°C. Autrement dit, non seulement on risque de rendre néant l'effet de la station de mélange en perturbant à nouveau la température du vent chaud au moyen de l'air de propulsion, mais également il faudra, ou bien augmenter la puissance des cowpers pour compenser cette perte de température, ou bien se contenter d'une température opérative du vent chaud plus basse.However, there is still a problem with the injection of solid fuels into the hot wind current in the nozzles. Indeed, for perfect control of the operation of the oven, it is necessary that the temperature of the hot wind is constant or, at least, that it is controllable. For this purpose, a mixing station has been provided upstream of the circular pipe in which a certain amount of cold air is mixed with the hot wind produced in the cowpers and the temperature of which is liable to fluctuate over time. peaks of fluctuation and reduce the temperature of the hot wind injected into the oven to a constant value. If the pneumatic route is used for injecting solid fuels into ovens, consider relatively large quantities of propellant fluids, which is usually air. However, to avoid self-ignition of the solid fuel in the pneumatic conveying lines, the temperature of the propelling air cannot exceed 80 to 120 ° C. In other words, not only is there a risk of nullifying the effect of the mixing station by again disturbing the temperature of the hot wind by means of the propelling air, but also it will be necessary, or else increase the power of the cowpers to compensate this loss of temperature, or else be satisfied with a lower operating temperature of the hot wind.

En conséquence, l'objectif de la présente invention est de prévoir un nouveau procédé d'injection de combustibles solides dans un four à cuve qui permette d'éviter les inconvénients précités, c'est-à-dire de ne pas influencer les paramètres d'injection du vent chaud. Un objectif complémentaire de l'invention est la réalisation d'une installation pour la mise en oeuvre de ce procédé.Consequently, the objective of the present invention is to provide a new method for injecting solid fuels into a shaft furnace which makes it possible to avoid the abovementioned drawbacks, that is to say not to influence the parameters d injection of hot wind. A complementary objective of the invention is the production of an installation for the implementation of this process.

Pour atteindre cet objectif, il est prévu un procédé d'injection de combustibles solides dans un four à cuve pourvu d'une conduite circulaire reliée à la base du four par une garniture de porte-vent et de tuyères d'injection de vent chaud, ce vent chaud étant produit dans une installation comprenant une soufflante, une batterie de cowpers et une station de mélange ayant deux entrées reliées respectivement à chacun des cowpers ainsi qu'à la soufflante par l'intermédiaire d'un dispositif de dosage automatique qui laisse passer dans la station de mélange la quantité dosée de vent froid nécessaire à la stabilisation de la température du vent chaud qui est envoyé, vers la conduite circulaire de façon que le vent chaud circulant dans celle-ci soit à température réglée et constante, et selon lequel on injecte dans le vent chaud avant sa pénétration dans le four des quantités dosées de combustibles solides sous forme pulvérulente, le transport et l'injection de ce combustible solide étant réalisés par voie pneumatique, caractérisé en ce que le fluide de propulsion pneumatique utilisé pour le transport et l'injection du combustible dans le vent chaud est constitué par au moins une partie de ladite quantité dosée de vent froid que l'on soutire entre le dispositif de dosage et la station de mélange et que l'on comprime à une pression suffisante pour la compensation des pertes de charges et l'injection du combustible dans le vent chaud et dans le four.To achieve this objective, there is provided a process for injecting solid fuels into a tank furnace provided with a circular pipe connected to the base of the furnace by a lining of wind-carrier and hot-air injection nozzles, this hot wind being produced in an installation comprising a blower, a battery of cowpers and a mixing station having two inlets connected respectively to each of the cowpers as well as to the blower by means of an automatic metering device which allows passage in the mixing station the metered quantity of cold wind necessary for stabilizing the temperature of the hot wind which is sent to the circular pipe so that the hot wind circulating in it is at a regulated and constant temperature, and according to which metered quantities of solid fuels in powder form are injected into the hot wind before it enters the furnace, the transport and injection of this solid fuel being real pneumatically driven, characterized in that the pneumatic propulsion fluid used for transporting and injecting the fuel in the hot wind consists of at least one part of the said metered amount of cold wind which is drawn between the metering device and the mixing station and which is compressed to a pressure sufficient to compensate for pressure drops and the injection of fuel into the hot wind and in the oven.

L'installation pour la mise en oeuvre de ce procédé est essentiellement caractérisée en ce que le circuit pneumatique d'injection de combustible est disposé parallèlement au circuit d'alimentation de la conduite circulaire en vent chaud et branché entre un point situé dans la conduite d'alimentation en air froid de la station de mélange, d'une part et chacune des tuyères d'autre part et comprenant un compresseur et au moins un dispositif d'admission du combustible solide.The installation for implementing this process is essentially characterized in that the pneumatic fuel injection circuit is arranged parallel to the circuit for supplying the circular pipe with hot wind and connected between a point located in the pipe d cold air supply to the mixing station, on the one hand and each of the nozzles on the other hand and comprising a compressor and at least one solid fuel intake device.

Selon un mode de réalisation avantageux, il est préférable de prévoir immédiatement en aval du compresseur un échangeur thermique afin de réduire la température de l'air à une température égale à celle immédiatement en amont du compresseur, et d'éviter ainsi le dépassement de la température d'auto- allumage du combustible.According to an advantageous embodiment, it is preferable to provide a heat exchanger immediately downstream of the compressor in order to reduce the air temperature to a temperature equal to that immediately upstream of the compressor, and thus avoid exceeding the fuel self-ignition temperature.

Le dispositif d'admission du combustible est de préférence constitué par une série de sas à rotor alvéolaire dont le nombre peut être égal à la moitié du nombre de tuyères de sorte qu'un sas soit associé à une paire de tuyères.The fuel intake device preferably consists of a series of airlock airlocks, the number of which can be equal to half the number of nozzles so that an airlock is associated with a pair of nozzles.

D'autres particularités ressortiront de la description détaillée d'un mode de réalisation présenté ci-dessous, à titre d'exemple, en référence à la figure unique qui montre un schéma synoptique d'une installation d'injection de combustibles solides selon la présente invention.Other particularities will emerge from the detailed description of an embodiment presented below, by way of example, with reference to the single figure which shows a block diagram of an installation for injecting solid fuels according to the present. invention.

Cette figure montre schématiquement un haut fourneau 2 pourvu d'une conduite circulaire 4 d'alimentation en vent chaud. Cette conduite circulaire 4 est reliée à la base du four au moyen d'une série de porte-vent 6 reliés à des tuyères non montrées encastrées dans la paroi du four. Le vent chaud pour l'alimentation de la conduite circulaire 4 et des porte-vent 6 est produit dans une installation 8 comprenant essentiellement une batterie de cowpers 12, 14 bien connus en soi. Ces cowpers sont, en fait, des fours destinés à réchauffer l'air froid en provenance d'une soufflante 10 jusqu'à une température supérieure à celle du vent chaud injecté dans le four. L'opération d'un tel cowper comporte deux phases, à savoir une phase de réchauffement et d'emmagasinage de chaleur et une phase de prélèvement de la chaleur emmagasinée et de réchauffement de l'air froid. Par conséquent, pour assurer une opération continue, il faut au moins une paire de cowpers travaillant en alternance.This figure schematically shows a blast furnace 2 provided with a circular pipe 4 for supplying hot wind. This circular pipe 4 is connected to the base of the furnace by means of a series of air carriers 6 connected to nozzles not shown embedded in the wall of the furnace. The hot wind for supplying the circular pipe 4 and the wind carriers 6 is produced in an installation 8 essentially comprising a battery of cowpers 12, 14 well known per se. These cowpers are, in fact, ovens intended to heat the cold air coming from a blower 10 to a temperature higher than that of the hot wind injected into the oven. The operation of such a cowper comprises two phases, namely a phase of warming and storage of heat and a phase of removal of the stored heat and warming of the cold air. Therefore, to ensure continuous operation, at least one pair of alternating cowpers is required.

La désignation de "froid" de l'air envoyé par la soufflante 10 dans les cowpers 12 et 14 n'est pas significative, étant donné que la température de cet air "froid" est approximativement 100 à 120°C à cause du réchauffement dans la soufflante 10. La température de l'air chaud à la sortie des cowpers dépend des besoins thermiques au niveau de l'injection dans le four. Lorsque l'air chaud injecté dans le four doit avoir une température d'environ 1200°C, le réchauffement produit dans les cowpers 12, 14 doit monter environ à 1300°C pour compenser les pertes thermiques et pouvoir assurer une température constante dans une station de mélange 16.The designation "cold" of the air sent by the blower 10 into the cowpers 12 and 14 is not significant, since the temperature of this "cold" air is approximately 100 to 120 ° C due to the heating in the blower 10. The temperature of the hot air leaving the cowpers depends on the thermal requirements for injection into the oven. When the hot air injected into the oven must have a temperature of approximately 1200 ° C, the heating produced in the cowpers 12, 14 must rise to approximately 1300 ° C to compensate for the heat losses and to be able to ensure a constant temperature in a station. mixing 16.

Le but de cette station de mélange 16 est d'assurer une température constante du vent chaud en vue de son injection dans le four. En effet, il n'est pas possible d'avoir une température constante et uniforme à la sortie des cowpers où il existe toujours des fluctuations de quelques dizaines de degrés. C'est donc la raison pour laquelle il faut chauffer le vent chaud dans les cowpers à une température suffisante afin de pouvoir la réduire à une température uniforme dans la station de mélange 16 par admission d'une quantité dosée de vent froid à travers une conduite 17 reliée à la soufflante 10. La quantité nécessaire d'air froid admis dans la station de mélange 16 à travers la conduite 17 est réglée automatiquement au moyen d'un clapet automatique 20 qui règle le débit d'air froid en fonction de la température du vent chaud dans la conduite circulaire. De cette manière, on est assuré que la température du vent chaud injecté dans le four reste constante.The purpose of this mixing station 16 is to ensure a constant temperature of the hot wind for injection into the oven. Indeed, it is not possible to have a constant and uniform temperature at the exit of the cowpers where there are always fluctuations of a few tens of degrees. This is the reason why it is necessary to heat the hot wind in the cowpers to a sufficient temperature in order to be able to reduce it to a uniform temperature in the mixing station 16 by admitting a metered amount of cold wind through a pipe. 17 connected to the blower 10. The necessary quantity of cold air admitted into the mixing station 16 through the line 17 is automatically adjusted by means of an automatic valve 20 which regulates the flow of cold air as a function of the temperature hot wind in the circular pipe. In this way, it is ensured that the temperature of the hot wind injected into the oven remains constant.

Cette installation 8 de production de vent chaud telle que représentée sur la figure constitue une installation classique bien connue en soi. Conformément à la présente invention, on greffe sur cette installation 8 un circuit parallèle 22 pour l'injection, par voie pneumatique, de combustibles solides dans chacune des tuyères du four. A cet effet, on a prévu une conduite 24 branchée sur la conduite d'admission d'air froid de la station de mélange 16 entre celle-ci et le clapet 20 et destinée à soutirer la quantité d'air nécessaire pour la propulsion pneumatique du combustible solide. Le réglage de la quantité d'air de propulsion dévié dans la conduite 24 est réglé automatiquement par un clapet 26 en fonction des besoins.This installation 8 for producing hot wind as shown in the figure constitutes a conventional installation well known per se. In accordance with the present invention, a parallel circuit 22 is grafted onto this installation 8 for the pneumatic injection of solid fuels into each of the furnace nozzles. For this purpose, there is provided a pipe 24 connected to the cold air intake pipe of the mixing station 16 between the latter and the valve 20 and intended to extract the quantity of air necessary for the pneumatic propulsion of the solid fuel. The adjustment of the amount of propelled air deflected in line 24 is automatically adjusted by a valve 26 as required.

Dans le circuit 22 on a prévu un compresseur 28 destiné à élever la pression de l'air de propulsion dans le circuit 22 de manière à compenser les pertes de charge et assurer l'injection dans le four. La différence de pression ΔP réalisée dans le compresseur 28 est généralement de 2 bars en comptant approximativement 1 bar pour la compensation des pertes de charge et une réserve d'un bar pour assurer l'injection. Par conséquent, si la pression du vent chaud à injecter dans le four est d'environ 2,5 bars la pression de l'air de propulsion en aval des compresseurs 28 est environ de 4,5 bars.In circuit 22 there is provided a compressor 28 intended to raise the pressure of the propelling air in circuit 22 so as to compensate for the pressure losses and ensure injection into the furnace. The pressure difference ΔP produced in the compressor 28 is generally 2 bars, counting approximately 1 bar for the compensation of the pressure losses and a reserve of one bar for the injection. Consequently, if the pressure of the hot wind to be injected into the furnace is approximately 2.5 bars, the pressure of the propelling air downstream from the compressors 28 is approximately 4.5 bars.

L'admission de combustible solide, sous forme poudreuse ou pulvérulente dans le circuit 22 est effectuée à l'aide d'un sas de soufflage à rotor alvéolaire 30 bien connu en soi. Ce combustible solide, qui peut être de la poudre de lignite ou de la poudre de charbon est ensuite propulsé à travers la conduite 32 dans les tuyères du four. On peut alimenter, par exemple, deux tuyères au moyen d'une seule conduite 32 de sorte que le nombre de conduites 32 et le nombre de sas 30 sera égal à la moitié du nombre de tuyères. Ce rapport peut être changé suivant les besoins.The admission of solid fuel, in powder or powder form into the circuit 22 is carried out using a blast airlock with a cellular rotor 30 well known per se. This com solid fuel, which can be lignite powder or coal powder, is then propelled through line 32 into the furnace nozzles. One can feed, for example, two nozzles by means of a single line 32 so that the number of lines 32 and the number of airlocks 30 will be equal to half the number of nozzles. This report can be changed as required.

Il est à noter que l'air de propulsion subit un réchauffement dans le compresseur 28. Afin d'éviter que la température de l'air de propulsion n'atteigne le seuil d'autoallumage du combustible solide et, également, pour réduire la température à une valeur approximativement égale à la température à l'endroit de soutirage de l'air de propulsion, c'est-à-dire entre le clapet 20 et la station 16, il est préférable de prévoir en aval du compresseur 28 un dispositif de refroidissement 33. L'activité de ce refroidisseur 33 peut être commandée automatiquement en fonction du réchauffement dans le compresseur 28. De cette manière, si la température de l'air froid circulant dans la conduite 17 est approximativement de 120°C on peut faire en sorte que la température de l'air de propulsion dans la conduite 32, notamment au moment de l'injection dans le four soit également de 120° environ.It should be noted that the propulsion air undergoes heating in the compressor 28. In order to prevent the temperature of the propelling air from reaching the self-ignition threshold of the solid fuel and, also, to reduce the temperature at a value approximately equal to the temperature at the place where the propelling air is drawn off, that is to say between the valve 20 and the station 16, it is preferable to provide a device downstream of the compressor 28 cooling 33. The activity of this cooler 33 can be controlled automatically as a function of the heating in the compressor 28. In this way, if the temperature of the cold air circulating in the pipe 17 is approximately 120 ° C. so that the temperature of the propelling air in line 32, in particular at the time of injection into the oven is also around 120 °.

Comme on peut le constater, l'intégration du circuit 22 dans le circuit 8 de production de vent chaud ne perturbe en aucune manière le fonctionnement de ce dernier et notamment la température du vent chaud injecté dans le four. En effet, la quantité d'air froid demandée par la station de mélange 16 pour le maintien d'une température constante du vent chaud est déterminée par le clapet 20 et cette quantité passera toujours à travers celui-ci. La différence est qu'une partie de l'air débitée par le clapet 20 n'est plus envoyée dans la station de mélange 16, mais à travers le circuit 22 de sorte que la quantité totale d'air froid mélangée au vent chaud produit par les cowpers ne change pas. Une partie du mélange, au lieu d'être effectuée dans la station de mélange 16, est maintenant effectuée au niveau de l'injection du combustible dans les porte-vent ou dans les tuyères.As can be seen, the integration of the circuit 22 into the circuit 8 for producing hot wind does not in any way disturb the operation of the latter and in particular the temperature of the hot wind injected into the oven. In fact, the quantity of cold air required by the mixing station 16 for maintaining a constant temperature of the hot wind is determined by the valve 20 and this quantity will always pass through it. The difference is that part of the air delivered by the valve 20 is no longer sent to the mixing station 16, but through the circuit 22 so that the total amount of cold air mixed with the hot wind produced by the cowpers don't change. Part of the mixing, instead of being carried out in the mixing station 16, is now carried out at the level of the injection of the fuel into the wind carriers or into the nozzles.

Pour le cas où le four est mis en "veilleuse", c'est-à-dire que la quantité de vent chaud est réduite au minimum, et que le clapet 26 est fermé, on a prévu un clapet 34 permettant l'admission d'air atmosphérique dans le circuit 22.In the case where the oven is put on "standby", that is to say that the quantity of hot wind is reduced to a minimum, and that the valve 26 is closed, a valve 34 is provided allowing the admission of atmospheric air in circuit 22.

Claims (6)

1. Process for the injection of solid fuel into a shaft furnace equipped with a circular conduit connected to the base of the furnace by a plurality of tuyere stocks and injection nozzles for the injection of hot air, said hot air being produced in an installation comprising a booster, set of cowpers and a mixing station with two inlets connected respectively to each of the cowpers and to the booster via an automatic regulating valve which reduces quantity of cold air flowing into the mixing station to the amount necessary for the stabilization of the temperature of the hot air injected into the circular conduit, so that the hot air circulating in the latter remains at a regulated and constant temperature, wherein solid fuel in powdered form is transported and injected pneumatically into the hot air before the injection into the furnace, characterized in that the fluid for the pneumatic transport and the injection of the fuel into the hot air consists in at least a part of the quantity of proportioned cold air which is removed at a point between the regulating valve and the mixing station and which is compressed at a sufficient pressure for compensation of the load losses and injection of the fuel into the furnace.
2. Process in accordance with claim 1, characterized in that, after having been compressed, the air is cooled in accordance with the reheating during this compression.
3. Installation for the implementation of the process in accordance with claims 1 or 2, in a blast furnace equipped with a circular conduit (4) connected to the base of the furnace (2) by a plurality of tuyere stocks (6) and injection nozzles for the injection of hot air produced in an installation (8) comprising a booster (10), a set of cowpers (12, 14) and a mixing station (16) with two inlets connected respectively through an automatic regulating valve (20) and a conduit (17) to the booster (10) and to each of the cowpers (12, 14) and an outlet supplying the circular conduit (4) with hot air with a controlled and constant temperature and a pneumatic circuit (22) for the injection of a fuel in powdered form into each of the tuyere stocks (6) or the injection nozzles, characterized in that this circuit (22) is arranged parallel to the hot air supply circuit of the circular conduit (4) and connected at a point situated in the cold air supply conduit (17) of the mixing station (16), on the one hand, and each of the tuyere stocks (6) or the injection nozzles on the other hand, and comprises a compressor (28) and at least one dispenser (30) for the solid fuel.
4. Installation in accordance with claim 3, characterized by a heat exchanger (33) provided between the compressor (28) and the solid fuel dispenser (30).
5. Installation in accordance with one of claims 3 or 4, characterized in that the solid fuel dispenser (30) is a cellular wheel sluice.
6. Installation in accordance with claim 5, characterized in that the number of cellular wheel sluices (30) is less than the number of nozzles (6) each sluice (30) being connected to several nozzles.
EP80103904A 1979-07-17 1980-07-09 Process and apparatus for the injection of solid fuel into a shaft furnace Expired EP0022549B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80103904T ATE7515T1 (en) 1979-07-17 1980-07-09 METHOD AND PLANT FOR INJECTING SOLID FUEL INTO A STACK FURNACE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
LU81519 1979-07-17
LU81519A LU81519A1 (en) 1979-07-17 1979-07-17 METHOD AND INSTALLATION FOR INJECTING SOLID FUELS INTO A TANK OVEN

Publications (2)

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EP0022549A1 EP0022549A1 (en) 1981-01-21
EP0022549B1 true EP0022549B1 (en) 1984-05-16

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Application Number Title Priority Date Filing Date
EP80103904A Expired EP0022549B1 (en) 1979-07-17 1980-07-09 Process and apparatus for the injection of solid fuel into a shaft furnace

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US (1) US4325312A (en)
EP (1) EP0022549B1 (en)
JP (1) JPS5616607A (en)
AR (1) AR221650A1 (en)
AT (1) ATE7515T1 (en)
AU (1) AU536120B2 (en)
BR (1) BR8004523A (en)
CA (1) CA1150505A (en)
DE (1) DE3067831D1 (en)
ES (1) ES494171A0 (en)
LU (1) LU81519A1 (en)
PL (1) PL225726A1 (en)
ZA (1) ZA804195B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3441082A1 (en) * 1984-07-23 1986-01-23 Japan Foundry Service Co., Ltd., Komaki, Aichi MELTING ARRANGEMENT

Families Citing this family (3)

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Publication number Priority date Publication date Assignee Title
JPS5852858U (en) * 1981-09-28 1983-04-09 テンパール工業株式会社 Electric leakage or disconnection
LU83671A1 (en) * 1981-10-02 1983-06-08 Wurth Paul Sa METHOD OF INJECTING QUANTITIES OF POWDERED MATERIALS BY PNEUMATIC ROUTE INTO A VESSEL PRESSURE ENCLOSURE AND APPLICATION TO A TANK OVEN
LU90150B1 (en) 1997-10-15 1999-04-16 Kuettner Gmbh & Co Kg Dr Method and device for blowing reducing agent into a shaft furnace

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US1535174A (en) * 1920-09-29 1925-04-28 Mcgregor Alexander Grant Art of feeding powdered coal to blast furnaces
US1505723A (en) * 1923-01-26 1924-08-19 United Eng Foundry Co Rotary feed member
US3197304A (en) * 1961-10-12 1965-07-27 United States Steel Corp Method for introducing coal into a blast furnace
BE630649A (en) * 1962-04-05
FR1364215A (en) * 1962-06-15 1964-06-19 Kellogg M W Co Injection system for flowable solids, for example for blast furnaces
BE623054A (en) * 1963-09-03
US3301544A (en) * 1964-02-18 1967-01-31 Babcock & Wilcox Co Blast furnace pulverized coal firing system
DE1256149B (en) * 1964-11-17 1967-12-07 Waeschle Maschf Gmbh Process for conveying heat-sensitive, powdery or granular material using compressed air
US3371917A (en) * 1965-10-21 1968-03-05 Buell Engineering Company Inc Apparatus for feeding fuel into a blast furnace
LU81388A1 (en) * 1979-06-15 1979-09-12 Wurth Paul Sa METHOD AND INSTALLATION FOR DOSING AND PNEUMATIC TRANSPORT OF SOLID MATERIALS TO A PRESSURE VESSEL

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3441082A1 (en) * 1984-07-23 1986-01-23 Japan Foundry Service Co., Ltd., Komaki, Aichi MELTING ARRANGEMENT

Also Published As

Publication number Publication date
US4325312A (en) 1982-04-20
AU536120B2 (en) 1984-04-19
ES8103579A1 (en) 1981-03-16
AR221650A1 (en) 1981-02-27
ZA804195B (en) 1981-07-29
PL225726A1 (en) 1981-05-08
CA1150505A (en) 1983-07-26
BR8004523A (en) 1981-02-03
ES494171A0 (en) 1981-03-16
EP0022549A1 (en) 1981-01-21
DE3067831D1 (en) 1984-06-20
ATE7515T1 (en) 1984-06-15
JPS5616607A (en) 1981-02-17
LU81519A1 (en) 1979-10-31
AU5962880A (en) 1981-01-22

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