Nothing Special   »   [go: up one dir, main page]

EP0844310B1 - Installation for deskulling the nozzles of a vacuum treating vessel for steel melts - Google Patents

Installation for deskulling the nozzles of a vacuum treating vessel for steel melts Download PDF

Info

Publication number
EP0844310B1
EP0844310B1 EP97402772A EP97402772A EP0844310B1 EP 0844310 B1 EP0844310 B1 EP 0844310B1 EP 97402772 A EP97402772 A EP 97402772A EP 97402772 A EP97402772 A EP 97402772A EP 0844310 B1 EP0844310 B1 EP 0844310B1
Authority
EP
European Patent Office
Prior art keywords
fingers
nozzles
deskulling
frame
installation according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP97402772A
Other languages
German (de)
French (fr)
Other versions
EP0844310A1 (en
Inventor
Patrick Tassot
Patrick Lebacon
Bernard Fournier
Jean-Claude Lecas
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.)
Prosertec
Original Assignee
Prosertec
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 Prosertec filed Critical Prosertec
Publication of EP0844310A1 publication Critical patent/EP0844310A1/en
Application granted granted Critical
Publication of EP0844310B1 publication Critical patent/EP0844310B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D99/00Subject matter not provided for in other groups of this subclass
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10Handling in a vacuum
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00Charging; Discharging; Manipulation of charge
    • F27D2003/0034Means for moving, conveying, transporting the charge in the furnace or in the charging facilities
    • F27D2003/0054Means to move molten metal, e.g. electromagnetic pump
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D25/00Devices or methods for removing incrustations, e.g. slag, metal deposits, dust; Devices or methods for preventing the adherence of slag
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00Charging; Discharging; Manipulation of charge
    • F27D3/14Charging or discharging liquid or molten material

Definitions

  • the subject of the present invention is a scouring installation of divers from a tank vacuum treatment of liquid steel.
  • a tank connected to a pumping means and provided, at its lower part, two vertical divers and parallel, each with an internal channel ensuring communication between the internal part of the tank and the outside of said tank.
  • Liquid steel treatment is carried out by putting the liquid steel in a pocket, then immersing the plungers in liquid steel, pumping the atmosphere inside the tank which causes the liquid steel to rise through the channels of divers in the tank and by injecting a gas into one of the channels thus causing intense circulation of liquid steel in the divers' channels.
  • the behavior of the refractory material divers is essential to the quality of the metallurgical treatment and a deficiency in this area often leads to a loss of efficiency in terms of rate liquid steel recirculation and therefore a loss sensitive productivity.
  • the first technique consists in carrying out the scouring from the ground using a shovel striking the refractory material and the gangue deposited when the height of the divers from the floor is low enough.
  • the second technique consists in carrying out the scouring from a work platform and at means of a set of struts if the distance between divers and the work floor is too large.
  • the gunning is done the most often from a cart and using a lance manual projection.
  • Document JP-A-62151260 describes an installation cleaning of tubular divers made of refractory material a liquid steel vacuum treatment tank comprising a tank bottom supporting the plungers arranged vertically and delimiting between them an intermediate space.
  • This installation includes a movable frame horizontally and vertically, comprising, in its part upper, means for simultaneously scraping the surface external of the vacuum treatment tank plungers.
  • the object of the invention is to propose an installation mechanical cleaning of divers from a tank treatment of the liquid steel which allows to act quickly and regularly on the still hot fouling matrix, therefore flowable and limit the uncontrolled growth of this gangue, while avoiding that the operators are found in the risk zone.
  • the subject of the invention is therefore an installation cleaning of tubular divers made of refractory material a liquid steel vacuum treatment tank comprising a bottom of the tank supporting the arranged divers vertically and delimiting between them an intermediate space, the installation including a movable frame horizontally and vertically and comprising at its part upper scraping means from bottom to top and simultaneous of the external surface of said plungers, characterized in that the scraping means are formed, for each of said divers, by rakes fitted with scouring fingers, distributed along a circumference and movable by actuation means between a position retracted in which the fingers of the rakes are spread of the outer surface of the divers and an active position in which the fingers of the rakes are in contact with the external surface of said plungers and in that each rake is formed by a crossbar with supports scouring fingers and a longitudinal handle extending perpendicular to said bar, a first end of the handle being connected to the bar and a second end of this handle being secured to a transverse axis pivot
  • a liquid steel vacuum treatment tank designated as a whole by the reference 1 and which includes a bell-shaped top 2, a ferrule intermediate 3 and a tank bottom 4.
  • the top of the tank 2 has a first stitching 5 on which is mounted an addition airlock 6 and a second tap 7 connected by a pipe to a pumping device, not shown.
  • the top of the tank 2, the intermediate shell 3 and the bottom of the tank 4 each has an envelope metal 8 and a coating 9 of refractory material.
  • the bottom of the tank 4 is provided with jambs, 10 and 11 respectively, on which two are mounted plungers, respectively 12 and 13, also made of material refractory and which delimit two channels, respectively 14 and 15, ensuring communication between the party internal of the tank and the outside of said tank.
  • a diver for example the diver 12 comprises a transverse conduit, not shown, intended the introduction of an inert gas into the corresponding channel.
  • Liquid steel treatment is carried out by putting the liquid steel in a pocket, then plunging the plungers 12 and 13 of the tank 1 into liquid steel, by pumping the atmosphere contained in inside the tank 1 which causes the rise of liquid steel through channels 14 and 15 in this tank 1 and an intense circulation of the liquid steel in the channels 14 and 15.
  • the scrub installation in accordance with the invention makes it possible to remove this gangue of fouling deposited on divers 12 and 13 as well as in the intermediate space 16 between said plungers 12 and 13.
  • FIGs 2 and 3 there is shown schematically a scrub installation 20 of the outer surface of divers 12 and 13 and which includes a frame 21 movable horizontally and vertically.
  • the frame 21 is equipped with means for horizontal movement to bring this frame 21 below divers 12 and 13 and which consist of a carriage 22 on which said frame 21 is disposed.
  • the carriage 22 can be moved horizontally by means of wheels 23 which cooperate with rails, not represented.
  • the carriage 22 is movable at large and at low speed to bring the frame 21 below the divers 12 and 13 and fine-tune the positioning of the frame 21 relative to these divers.
  • the frame 21 is equipped with means vertical displacement.
  • This frame 21 which has a generally parallelepiped shape has, on its lateral uprights, rollers 24 which cooperate with vertical rails 25.
  • the lateral uprights 25 of the frame 21 are provided with cylinders 26, for example hydraulic, whose control rods are supported on the carriage 22 to vertically move the frame 21, as will be seen later.
  • the frame 21 comprises, at its upper part, scraping means 30 from bottom to the top and simultaneous of the external surface of each diver 12 and 13.
  • the frame 21 also includes, at its upper part, means 50 for scouring the intermediate space 16 between the plungers 12 and 13.
  • the scraping means 30 are formed by rakes 31 provided of scouring fingers 32 and distributed according to a circumference so as to substantially cover the part accessible from the external surface of the corresponding plunger.
  • Each rake 31 is movable by actuation means which will be described later, between a retracted position in which the fingers 32 of these rakes 31 are moved away from the external surface divers 12 and 13 and an active position in which the fingers 32 of these rakes 31 are in contact with the external surface of said plungers 12 and 13.
  • each rake 31 is movable by pivoting between the two positions.
  • each rake 31 can be movable by longitudinal sliding between the two positions.
  • each rake 31 is formed, of a part, by a crossbar 33 comprising supports 34 of the scrub fingers 32 regularly distributed over said crossbar 33 and, on the other part, by a longitudinal handle 35 extending perpendicularly to said crossbar 33.
  • each rake 31 has three scouring fingers 32.
  • each rake 31 can have a higher number of scrub fingers 32 or inside three and each rake 31 can have a different number of scouring fingers 32 in depending on the area of the diver to be covered and the dimension of this diver.
  • each support 34 includes lights 36 for the passage of fixing bolts 37 of a scouring finger 32 on the corresponding support 34.
  • each rake 31 has a first end 35a connected to the crossbar 33 of the corresponding rake 31 and a second end 35b integral with a transverse axis 38 of pivoting of the rake 31.
  • each rake 31 is connected to actuating means for moving the rake 31 as well as the scouring fingers 32 between the two positions.
  • each rake 31 includes a jack 39 for example hydraulic comprising a body 39a pivotally mounted on an axis 40 connected by fixing elements on the frame 21 and a control rod 39b whose free end is pivotally connected to the transverse axis 38 of the sleeve 35 corresponding, by at least one link 41.
  • a jack 39 for example hydraulic comprising a body 39a pivotally mounted on an axis 40 connected by fixing elements on the frame 21 and a control rod 39b whose free end is pivotally connected to the transverse axis 38 of the sleeve 35 corresponding, by at least one link 41.
  • control rod 39b of the cylinder 39 is connected to the transverse axis 38 by two rods parallel 41 connected to each other by a flange 45 (Figs. 4 and 6).
  • Each set formed by a rake 31, a transverse axis 38, a jack 39 and an axis 40 is connected to the frame 21 by support elements formed for example by flanges, respectively 46, 47 and 48 (Figs. 5 and 6).
  • Each scouring finger 32 forms with horizontal an angle between 30 and 60 ° when the rake 31 is in the active position.
  • These scouring means 50 are formed by at least two opposing and movable scouring fingers 51 horizontally.
  • Each scouring finger 51 of the space intermediate 16 is movable by actuation means between a retracted position in which the scouring fingers 51 are separated from the intermediate space 16 and an active position in which the fingers scrub 51 are in quasi-contact one against the other and are positioned in said intermediate space 16.
  • Each scouring finger 51 is mounted on a support 52 secured to a rod 53 connected to the means actuation.
  • the support 52 of the scouring finger 51 includes lights, not shown, for passing bolts 54 for fixing the scouring finger 51 to its support 52.
  • the rod 53 is slidably mounted in a supported sheath 54 by the frame 21.
  • each finger scouring 51 are formed by a jack 55 for example hydraulics which conventionally includes a firstly, a body 55a connected to the frame 21 and, secondly, a control rod 55b connected by its free end to rod 53.
  • each scouring finger 51 can be moved by pivoting between the two positions.
  • the frame 21 is equipped at its upper part a hopper 17 which allows to channel the fouling gangue detachment of divers 12 and 13 by the fingers scrub 32 and 51 in a collecting tank, not shown, arranged at the base of this frame 21.
  • This recovery tray is removable and can be emptied by means of a handling device.
  • the scouring fingers 32 and 51 are by example in high temperature abrasion resistant steel.
  • the operator commands through, for example a remote control, the movement of the assembly by the frame 21 and the carriage 22 to bring with precision this frame 21 below the plungers 12 and 13.
  • Rakes 31 means 30 for cleaning are in the raised position, as shown in lines mixed in FIG. 4, and the scouring fingers 51 means 50 for cleaning the intermediate space 16 are in the retracted position.
  • the operator controls the rise of the frame 21 by means of the jacks 26 so that this frame 21 moves vertically on the rails 25 and that the rakes 31 of the scrubbing means 30 come position at the bottom of the divers 12 and 13.
  • the operator controls the rams 39 of the rakes 21 which has the effect to tilt these rakes 31 around the transverse axis 38 in the active position so that the scouring fingers 32 are positioned against the fouling matrix deposited on the external surface divers 12 and 13.
  • the operator actuates the jacks 26 which gradually lift the frame 21 so that the fingers scrub 32 scrape from bottom to top gangue fouling deposited on divers 12 and 13.
  • the cleaning of divers 12 and 13 by fingers 32 is therefore carried out from the bottom up which allows to maintain the refractory material constituting these compression divers.
  • refractory materials have a ten times greater resistance in compression by compared to traction.
  • the surface scrub operation external of divers 12 and 13 can be performed in one or several passes depending on the importance of the thickness of gangue.
  • the rakes 31 are raised between each pass and each cleaning pass is carried out from the bottom to the top so as to hold the refractory material of these plungers 12 and 13 in compression.
  • the number of scouring fingers 32 is depending on the diameter of divers 12 and 13. In the case divers from 500 to 750mm in diameter, the number of scouring fingers 32 per plunger is nine or twelve. For smaller divers, six fingers scouring is sufficient.
  • the operator actuates the jacks 55 so that the fingers scrub 51 moves horizontally and are positioned in the intermediate space 16, as shown in figure 3.
  • the operator actuates the jacks 26 so as to lower the frame 21 which also causes the descent of the scouring fingers 51 over all the height of the intermediate space 16 between the divers 12 and 13.
  • the gangue of fouling taken off by divers 12 and 13 is funneled through the hopper 17 and falls in the recycling bin.
  • All the installation operations of scouring is carried out from a central control such as a radio control and / or a console arranged on the carriage 22 and the scouring of the divers 12 and 13 is completed in two or three minutes from from the moment the positioning of the scrub fingers is judged as correct by the operator according to the fouling rate encountered.
  • a central control such as a radio control and / or a console arranged on the carriage 22 and the scouring of the divers 12 and 13 is completed in two or three minutes from from the moment the positioning of the scrub fingers is judged as correct by the operator according to the fouling rate encountered.
  • the scrub installation according to the invention allows rapid operation at high temperatures in a temperature zone where the gangue is still subject creep which makes it easier to detach, while giving the operator working conditions greatly improved.
  • the descaling operation being carried out simultaneously at the divers' level, the intervention time is fast which allows for a gunning of the external and internal surfaces of the divers 12 and 13 by means of a suitable machine and drying of the gunning product before reuse of the tank vacuum treatment.
  • the frame 21 of the installation of scouring can also be fitted with lances gunning which allow to project a product on external and internal surfaces of divers 12 and 13.
  • each rake 31 in relation to the external surface of the divers 12 and 13 and the positioning of the scrub fingers 51 of the intermediate space 16 are adjustable as a function of the thickness of the fouling matrix and this by acting separately on the stroke of the cylinders 39 of positioning of rakes 31 and cylinders 55 of positioning of the scrub fingers 51.
  • each finger scouring 32 and 51 on its corresponding support 34 and 52 is adjustable according to the wear of these fingers cleaning.
  • each rake 31 is adjustable according to this ovalization.
  • the installation according to the invention makes it possible to extend the service life of refractory material constituting the plungers of the treatment tank and ability to perform different operations in a way safe and fast and improve working conditions operator.
  • the frequency of operations of scouring can be increased for productivity of the vacuum treatment tank.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Mechanical Engineering (AREA)
  • Cleaning In General (AREA)
  • Furnace Details (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
  • Coating With Molten Metal (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)

Abstract

An installation for cleaning the tubular refractory plungers (12, 13) of a vat (1) for the treatment under vacuum of liquid steel comprising a vat base supporting the plungers (12, 13) arranged vertically and delimiting between them an intermediary space (16). It includes a frame (21) that can be displaced horizontally and vertically and incorporating, at its upper part, some means (30) for scraping from the bottom to the top and simultaneously the external surface of the plungers (12, 13). The means for scraping the plungers (12, 13) are made up of some rakes fitted with scraping fingers, arranged around a circumference and able to be arranged between a retracted position in which the fingers of the rakes are separated from the external surface of the plungers and an active position in which the fingers of the rakes are in contact with the external surface of the plungers. Each rake is formed by a transverse bar and can be displaced between the two positions by a pivoting action generated by, for example, a hydraulic piston. The scraping fingers are mounted at an angle of between 30 and 60 degrees with respect to the horizontal plane and the position of each can be regulated. The frame also incorporates a container for the recovery of the gangue material removed from the plungers and some gunning lances for recoating the plungers.

Description

La présente invention a pour objet une installation de décrassage des plongeurs d'une cuve de traitement sous vide de l'acier liquide.The subject of the present invention is a scouring installation of divers from a tank vacuum treatment of liquid steel.

Au cours de l'élaboration de l'acier liquide, on effectue souvent un traitement qui consiste à faire passer l'acier liquide dans une enceinte dans laquelle on fait le vide à l'aide de moyens de pompage.During the development of liquid steel, we often carry out a treatment which consists in making pass the liquid steel through an enclosure in which a vacuum is created using pumping means.

Pour faire ce traitement, on peut utiliser une cuve reliée à un moyen de pompage et munie, à sa partie inférieure, de deux plongeurs verticaux et parallèles, comportant chacun un canal interne assurant une communication entre la partie interne de la cuve et l'extérieur de ladite cuve.To do this treatment, you can use a tank connected to a pumping means and provided, at its lower part, two vertical divers and parallel, each with an internal channel ensuring communication between the internal part of the tank and the outside of said tank.

Le traitement de l'acier liquide est réalisé en mettant l'acier liquide dans une poche, puis en plongeant les plongeurs dans l'acier liquide, en pompant l'atmosphère contenu à l'intérieur de la cuve ce qui provoque la montée de l'acier liquide par les canaux des plongeurs dans la cuve et en injectant un gaz dans un des canaux provoquant ainsi une circulation intense de l'acier liquide dans les canaux des plongeurs.Liquid steel treatment is carried out by putting the liquid steel in a pocket, then immersing the plungers in liquid steel, pumping the atmosphere inside the tank which causes the liquid steel to rise through the channels of divers in the tank and by injecting a gas into one of the channels thus causing intense circulation of liquid steel in the divers' channels.

Ainsi, un canal est parcouru par un courant ascendant et l'autre canal est parcouru par un courant descendant.So, a channel is crossed by a current ascending and the other channel is traversed by a current descending.

Au cours de l'immersion des plongeurs dans l'acier liquide et lors de la remontée de la cuve et après traitement de l'acier liquide, il se forme sur la surface externe des plongeurs une gangue d'encrassement ou garni constitué par des engraissements chauds formés d'acier, de laitier et d'alumine.During the immersion of the divers in liquid steel and when raising the tank and after treatment of the liquid steel, it forms on the outer surface of divers a gangue of fouling or filled with hot fattening formed steel, slag and alumina.

Or, on sait que le fonctionnement des cuves de traitement sous vide de l'acier liquide est très dépendant de la tenue de vie des matériaux réfractaires, d'une part de la cuve de traitement et d'autre part des plongeurs.However, we know that the operation of tanks vacuum treatment of liquid steel is very depending on the lifetime of the refractory materials, on the one hand of the treatment tank and on the other hand divers.

En particulier, la tenue du matériau réfractaire des plongeurs est indispensable à la qualité du traitement métallurgique et une carence dans ce domaine conduit souvent à une perte d'efficacité en terme de taux de recirculation de l'acier liquide et donc une perte de productivité sensible.In particular, the behavior of the refractory material divers is essential to the quality of the metallurgical treatment and a deficiency in this area often leads to a loss of efficiency in terms of rate liquid steel recirculation and therefore a loss sensitive productivity.

De ce fait, selon les nuances de l'acier traité, un entretien notamment des plongeurs doit être réalisé tous les quatre à six traitements.Therefore, depending on the nuances of the steel treated, a maintenance including divers must be performed every four to six treatments.

Pour cela, il est nécessaire dans un premier temps de décrasser les plongeurs de la gangue d'encrassement et dans un deuxième temps d'effectuer une opération de gunitage sur les surfaces exposées du matériau réfractaire avec un pisé de projection adapté.For this, it is necessary in a first time to clear the fouling gangue divers and then perform an operation of gunning on the exposed surfaces of the material refractory with an adapted projection rammed earth.

Pour le décrassage de la surface externe des plongeurs, plusieurs techniques sont utilisées jusqu'à présent.For cleaning the external surface of divers, several techniques are used up to present.

La première technique consiste à réaliser le décrassage à partir du sol au moyen d'une pelle en percutant le matériau réfractaire et la gangue déposée lorsque la hauteur des plongeurs par rapport au plancher de travail est suffisamment basse.The first technique consists in carrying out the scouring from the ground using a shovel striking the refractory material and the gangue deposited when the height of the divers from the floor is low enough.

La seconde technique consiste à réaliser le décrassage à partir d'une plate-forme de travail et au moyen d'un jeu de jambes de force si la distance entre les plongeurs et le plancher de travail est trop importante.The second technique consists in carrying out the scouring from a work platform and at means of a set of struts if the distance between divers and the work floor is too large.

Ensuite, le gunitage est réalisé le plus souvent à partir d'un chariot et au moyen d'une lance manuelle de projection.Then the gunning is done the most often from a cart and using a lance manual projection.

Mais, ces différentes opérations présentent de nombreux inconvénients.But, these different operations present many disadvantages.

En effet, le décrassage au moyen d'une pelle mécanique contribue à ébranler le matériau réfractaire des plongeurs et donc à diminuer sensiblement la performance générale de l'installation de traitement de l'acier liquide.Indeed, scouring by means of a shovel mechanical helps to shake the refractory material of divers and therefore to significantly decrease the overall performance of the liquid steel treatment plant.

Dans le cas du décrassage des plongeurs à partir d'une plate-forme et de jambes de force, l'opérateur est directement exposé à la chaleur, ce qui contribue à rendre le poste de travail particulièrement pénible du fait de la température élevée et des risques de chutes de loups provenant du haut de la cuve.In the case of scouring divers from of a platform and struts, the operator is directly exposed to heat, which helps make the particularly arduous work station due to the temperature high risk of wolves falling from from the top of the tank.

De plus, l'opérateur ne dispose pas de nombreux points d'appui ce qui diminue sensiblement la qualité de décrassage et augmente fortement le temps d'intervention.In addition, the operator does not have many support points which significantly reduces the quality of scrub and greatly increases the intervention time.

Par ailleurs, dans tous les cas, il est quasiment impossible de nettoyer proprement la zone comprise entre les plongeurs.In addition, in all cases, it is almost impossible to clean the area between divers.

En ce qui concerne le gunitage, l'utilisation d'une lance manuelle est tout à fait compatible avec la projection du produit sur la surface extérieure du plongeur. Par contre la réparation de l'intérieur ou de la base des plongeurs conduit à des rebonds de produits très important pouvant aller jusqu'à 50% ce qui induit des consommations importantes de produits et rend l'opération particulièrement difficile pour l'opérateur.Regarding gunning, the use of a manual lance is entirely compatible with projection of the product on the outer surface of the plunger. On the other hand, the repair of the interior or the base of the divers leads to very large product rebounds up to 50% which leads to consumption important products and makes the operation particularly difficult for the operator.

Le document JP-A-62151260 décrit une installation de décrassage des plongeurs tubulaires en matériau réfractaire d'une cuve de traitement sous vide de l'acier liquide comportant un bas de cuve supportant les plongeurs disposés verticalement et délimitant entre eux un espace intermédiaire. Cette installation comprend un bâti déplaçable horizontalement et verticalement, comportant, à sa partie supérieure, des moyens de raclage simultané de la surface externe des plongeurs de la cuve de traitement sous vide. Document JP-A-62151260 describes an installation cleaning of tubular divers made of refractory material a liquid steel vacuum treatment tank comprising a tank bottom supporting the plungers arranged vertically and delimiting between them an intermediate space. This installation includes a movable frame horizontally and vertically, comprising, in its part upper, means for simultaneously scraping the surface external of the vacuum treatment tank plungers.

L'invention a pour but de proposer une installation mécanique de décrassage des plongeurs d'une cuve de traitement de l'acier liquide qui permet d'agir rapidement et régulièrement sur la gangue d'encrassement encore chaude, donc fluable et de limiter la croissance non contrôlée de cette gangue, tout en évitant que les opérateurs se trouvent dans la zone à risques.The object of the invention is to propose an installation mechanical cleaning of divers from a tank treatment of the liquid steel which allows to act quickly and regularly on the still hot fouling matrix, therefore flowable and limit the uncontrolled growth of this gangue, while avoiding that the operators are found in the risk zone.

L'invention a donc pour objet une installation de décrassage des plongeurs tubulaires en matériau réfractaire d'une cuve de traitement sous vide de l'acier liquide comportant un bas de cuve supportant les plongeurs disposés verticalement et délimitant entre eux un espace intermédiaire, l'installation comprenant un bâti déplaçable horizontalement et verticalement et comportant à sa partie supérieure des moyens de raclage du bas vers le haut et simultané de la surface externe desdits plongeurs, caractérisée en ce que les moyens de raclage sont formés, pour chacun desdits plongeurs, par des râteaux munis de doigts de décrassage, répartis selon une circonférence et déplaçables par des moyens d'actionnement entre une position escamotée dans laquelle les doigts des râteaux sont écartés de la surface externe des plongeurs et une position active dans laquelle les doigts des râteaux sont en contact avec la surface externe desdits plongeurs et en ce que chaque râteau est formé par une barre transversale comportant des supports des doigts de décrassage et par un manche longitudinal s'étendant perpendiculairement à ladite barre, une première extrémité du manche étant reliée à la barre et une seconde extrémité de ce manche étant solidaire d'un axe transversal de pivotement dudit râteau, relié aux moyens d'actionnement.The subject of the invention is therefore an installation cleaning of tubular divers made of refractory material a liquid steel vacuum treatment tank comprising a bottom of the tank supporting the arranged divers vertically and delimiting between them an intermediate space, the installation including a movable frame horizontally and vertically and comprising at its part upper scraping means from bottom to top and simultaneous of the external surface of said plungers, characterized in that the scraping means are formed, for each of said divers, by rakes fitted with scouring fingers, distributed along a circumference and movable by actuation means between a position retracted in which the fingers of the rakes are spread of the outer surface of the divers and an active position in which the fingers of the rakes are in contact with the external surface of said plungers and in that each rake is formed by a crossbar with supports scouring fingers and a longitudinal handle extending perpendicular to said bar, a first end of the handle being connected to the bar and a second end of this handle being secured to a transverse axis pivoting said rake, connected to the actuating means.

Selon d'autres caractéristiques de l'invention :

  • le bâti comporte à sa partie supérieure des moyens de décrassage de l'espace intermédiaire entre lesdits plongeurs,
  • le bâti est équipé de moyens de déplacement horizontal pour amener ledit bâti au-dessous desdits plongeurs,
  • le bâti est équipé de moyens de déplacement vertical pour amener les moyens de raclage au niveau desdits plongeurs,
  • chaque râteau est déplaçable par coulissement longitudinal entre les deux positions,
  • chaque râteau est déplaçable par pivotement entre les deux positions,
  • les moyens d'actionnement du pivotement de chaque râteau comprennent un vérin par exemple hydraulique comportant un corps pivotant sur un axe et une tige de commande dont l'extrémité libre est reliée à l'axe transversal du manche correspondant par au moins une biellette,
  • chaque doigt de décrassage forme avec l'horizontale un angle compris entre 30 et 60°,
  • les moyens de décrassage de l'espace intermédiaire entre les plongeurs comportent au moins deux doigts de décrassage opposés et déplaçables par des moyens d'actionnement entre une position escamotée dans laquelle les doigts de décrassage sont écartés de l'espace intermédiaire et une position active dans laquelle lesdits doigts de décrassage sont positionnés dans ledit espace intermédiaire,
  • chaque doigt de décrasse de l'espace intermédiaire est monté sur un support déplaçable par coulissement dans un fourreau d'une tige reliée aux moyens d'actionnement,
  • la position de chaque doigt de décrassage sur son support est réglable,
  • le bâti comporte à sa partie supérieure une trémie,
  • le bâti comporte un bac de récupération de la gangue d'encrassement enlevée des plongeurs,
  • le bâti est équipé de lances de gunitage des surfaces externe et interne des plongeurs.
According to other characteristics of the invention:
  • the frame comprises at its upper part means for cleaning the intermediate space between said plungers,
  • the frame is equipped with horizontal displacement means for bringing said frame below said plungers,
  • the frame is equipped with vertical displacement means for bringing the scraping means to the level of said plungers,
  • each rake can be moved by longitudinal sliding between the two positions,
  • each rake can be moved by pivoting between the two positions,
  • the means for actuating the pivoting of each rake comprise a hydraulic cylinder, for example comprising a body pivoting on an axis and a control rod whose free end is connected to the transverse axis of the corresponding handle by at least one connecting rod,
  • each scouring finger forms an angle between 30 and 60 ° with the horizontal,
  • the scouring means of the intermediate space between the plungers comprise at least two opposite scouring fingers which can be moved by actuation means between a retracted position in which the scouring fingers are separated from the intermediate space and an active position in which said scouring fingers are positioned in said intermediate space,
  • each scrub finger of the intermediate space is mounted on a support that can be moved by sliding in a sheath of a rod connected to the actuation means,
  • the position of each scouring finger on its support is adjustable,
  • the frame has a hopper at its upper part,
  • the frame includes a collecting tank for the gangue of fouling removed from the divers,
  • the frame is equipped with gunning lances of the external and internal surfaces of the divers.

Les caractéristiques et avantages de l'invention apparaítront au cours de la description qui va suivre, donnée à titre d'exemple et faite en référence aux dessins annexés, sur lesquels :

  • la Fig. 1 est une vue schématique en coupe d'une cuve de traitement sous vide de l'acier liquide,
  • la Fig. 2 est une vue schématique en perspective d'une installation de décrassage conforme à l'invention,
  • la Fig. 3 est une vue schématique de dessus de l'installation de décrassage conforme à l'invention,
  • la Fig. 4 est une vue de côté d'un râteau de raclage de la surface externe d'un plongeur de la cuve de traitement,
  • la Fig. 5 est une vue de dessus de la Fig.4,
  • la Fig. 6 est une vue de côté montrant les moyens d'actionnement d'un râteau de raclage,
  • la Fig.7 est une vue de côté des moyens de raclage de l'espace intermédiaire entre les plongeurs.
The characteristics and advantages of the invention will appear during the description which follows, given by way of example and made with reference to the accompanying drawings, in which:
  • Fig. 1 is a schematic sectional view of a vacuum treatment tank for liquid steel,
  • Fig. 2 is a schematic perspective view of a scouring installation according to the invention,
  • Fig. 3 is a schematic top view of the scouring installation according to the invention,
  • Fig. 4 is a side view of a scraper rake of the external surface of a plunger of the treatment tank,
  • Fig. 5 is a top view of FIG. 4,
  • Fig. 6 is a side view showing the means for actuating a scraper rake,
  • Fig.7 is a side view of the scraping means of the intermediate space between the plungers.

Sur la Fig.1, on a représenté schématiquement une cuve de traitement sous vide de l'acier liquide, désignée dans son ensemble par la référence 1 et qui comprend un haut de cuve 2 en forme de cloche, une virole intermédiaire 3 et un bas de cuve 4.In Fig. 1, there is shown schematically a liquid steel vacuum treatment tank, designated as a whole by the reference 1 and which includes a bell-shaped top 2, a ferrule intermediate 3 and a tank bottom 4.

Le haut de cuve 2 comporte un premier piquage 5 sur lequel est monté un sas à additions 6 et un deuxième piquage 7 relié par une canalisation à un dispositif de pompage, non représenté.The top of the tank 2 has a first stitching 5 on which is mounted an addition airlock 6 and a second tap 7 connected by a pipe to a pumping device, not shown.

Le haut de cuve 2, la virole intermédiaire 3 et le bas de cuve 4 comporte chacun une enveloppe métallique 8 et un revêtement 9 en matériau réfractaire.The top of the tank 2, the intermediate shell 3 and the bottom of the tank 4 each has an envelope metal 8 and a coating 9 of refractory material.

Le bas de cuve 4 est muni de jambages, respectivement 10 et 11, sur lesquels sont montés deux plongeurs, respectivement 12 et 13, également en matériau réfractaire et qui délimitent deux canaux, respectivement 14 et 15, assurant une communication entre la partie interne de la cuve et l'extérieur de ladite cuve.The bottom of the tank 4 is provided with jambs, 10 and 11 respectively, on which two are mounted plungers, respectively 12 and 13, also made of material refractory and which delimit two channels, respectively 14 and 15, ensuring communication between the party internal of the tank and the outside of said tank.

Un plongeur, par exemple le plongeur 12 comporte un conduit transversal, non représenté, destiné à l'introduction d'un gaz inerte dans le canal correspondant.A diver, for example the diver 12 comprises a transverse conduit, not shown, intended the introduction of an inert gas into the corresponding channel.

Le traitement de l'acier liquide est réalisé en mettant l'acier liquide dans une poche, puis en plongeant les plongeurs 12 et 13 de la cuve 1 dans l'acier liquide, en pompant l'atmosphère contenue à l'intérieur de la cuve 1 ce qui provoque la montée de l'acier liquide par les canaux 14 et 15 dans cette cuve 1 et une circulation intense de l'acier liquide dans les canaux 14 et 15.Liquid steel treatment is carried out by putting the liquid steel in a pocket, then plunging the plungers 12 and 13 of the tank 1 into liquid steel, by pumping the atmosphere contained in inside the tank 1 which causes the rise of liquid steel through channels 14 and 15 in this tank 1 and an intense circulation of the liquid steel in the channels 14 and 15.

Au cours de l'immersion des plongeurs 12 et 13 dans l'acier liquide et lors de la remontée de la cuve 1 après traitement de l'acier liquide, il se forme sur la surface externe des plongeurs 12 et 13 une gangue d'encrassement ou garni constitué par des engraissements formés d'acier, de laitier et d'alumine.During the immersion of divers 12 and 13 in liquid steel and when raising the tank 1 after treatment of the liquid steel, it forms on the outer surface of divers 12 and 13 a gangue fouling or lined with fattening formed of steel, slag and alumina.

L'installation de décrassage conforme à l'invention permet de retirer cette gangue d'encrassement déposée sur les plongeurs 12 et 13 ainsi que dans l'espace intermédiaire 16 entre lesdits plongeurs 12 et 13.The scrub installation in accordance with the invention makes it possible to remove this gangue of fouling deposited on divers 12 and 13 as well as in the intermediate space 16 between said plungers 12 and 13.

Sur les figures 2 et 3, on a représenté schématiquement une installation de décrassage 20 de la surface externe des plongeurs 12 et 13 et qui comprend un bâti 21 déplaçable horizontalement et verticalement.In Figures 2 and 3, there is shown schematically a scrub installation 20 of the outer surface of divers 12 and 13 and which includes a frame 21 movable horizontally and vertically.

Pour cela, le bâti 21 est équipé de moyens de déplacement horizontal pour amener ce bâti 21 au-dessous des plongeurs 12 et 13 et qui sont constitués par un chariot 22 sur lequel est disposé ledit bâti 21.For this, the frame 21 is equipped with means for horizontal movement to bring this frame 21 below divers 12 and 13 and which consist of a carriage 22 on which said frame 21 is disposed.

Le chariot 22 est déplaçable horizontalement grâce à des roues 23 qui coopèrent avec des rails, non représentés. The carriage 22 can be moved horizontally by means of wheels 23 which cooperate with rails, not represented.

Le chariot 22 est déplaçable à grande et à petite vitesse pour amener le bâti 21 au-dessous des plongeurs 12 et 13 et d'ajuster avec précision le positionnement du bâti 21 par rapport à ces plongeurs.The carriage 22 is movable at large and at low speed to bring the frame 21 below the divers 12 and 13 and fine-tune the positioning of the frame 21 relative to these divers.

Par ailleurs, le bâti 21 est équipé de moyens de déplacement vertical.Furthermore, the frame 21 is equipped with means vertical displacement.

Ce bâti 21 qui a une forme générale parallélépipédique comporte, sur ses montants latéraux, des galets 24 qui coopèrent avec des rails verticaux 25.This frame 21 which has a generally parallelepiped shape has, on its lateral uprights, rollers 24 which cooperate with vertical rails 25.

Les montants latéraux 25 du bâti 21 sont pourvus de vérins 26, par exemple hydrauliques, dont les tiges de commande prennent appui sur le chariot 22 pour déplacer verticalement le bâti 21, comme on le verra ultérieurement.The lateral uprights 25 of the frame 21 are provided with cylinders 26, for example hydraulic, whose control rods are supported on the carriage 22 to vertically move the frame 21, as will be seen later.

Par ailleurs, le bâti 21 comporte, à sa partie supérieure, des moyens 30 de raclage du bas vers le haut et simultané de la surface externe de chaque plongeur 12 et 13.Furthermore, the frame 21 comprises, at its upper part, scraping means 30 from bottom to the top and simultaneous of the external surface of each diver 12 and 13.

D'autre part, le bâti 21 comporte également, à sa partie supérieure, des moyens 50 de décrassage de l'espace intermédiaire 16 entre les plongeurs 12 et 13.On the other hand, the frame 21 also includes, at its upper part, means 50 for scouring the intermediate space 16 between the plungers 12 and 13.

En se reportant maintenant aux figures 3 à 6, on va décrire les moyens 30 de raclage de la surface externe d'un plongeur, les moyens 30 de raclage de l'autre plongeur étant identiques.Referring now to Figures 3 to 6, we will describe the means 30 for scraping the surface external of a plunger, the means 30 for scraping the other diver being identical.

Ainsi que représenté sur ces figures, les moyens 30 de raclage sont formés par des râteaux 31 munis de doigts de décrassage 32 et répartis selon une circonférence de façon à couvrir sensiblement la partie accessible de la surface externe du plongeur correspondant.As shown in these figures, the scraping means 30 are formed by rakes 31 provided of scouring fingers 32 and distributed according to a circumference so as to substantially cover the part accessible from the external surface of the corresponding plunger.

Chaque râteau 31 est déplaçable par des moyens d'actionnement qui seront décrit ultérieurement, entre une position escamotée dans laquelle les doigts 32 de ces râteaux 31 sont écartés de la surface externe des plongeurs 12 et 13 et une position active dans laquelle les doigts 32 de ces râteaux 31 sont en contact avec la surface externe desdits plongeurs 12 et 13.Each rake 31 is movable by actuation means which will be described later, between a retracted position in which the fingers 32 of these rakes 31 are moved away from the external surface divers 12 and 13 and an active position in which the fingers 32 of these rakes 31 are in contact with the external surface of said plungers 12 and 13.

Dans le mode de réalisation représenté sur les figures, chaque râteau 31 est déplaçable par pivotement entre les deux positions.In the embodiment shown on the figures, each rake 31 is movable by pivoting between the two positions.

Selon une variante, chaque râteau 31 peut être déplaçable par coulissement longitudinal entre les deux positions.According to a variant, each rake 31 can be movable by longitudinal sliding between the two positions.

Comme représenté plus particulièrement sur les figures 4 à 6, chaque râteau 31 est formé, d'une part, par une barre transversale 33 comportant des supports 34 des doigts de décrassage 32 régulièrement répartis sur ladite barre transversale 33 et, d'autre part, par un manche longitudinal 35 s'étendant perpendiculairement à ladite barre transversale 33.As shown more particularly on Figures 4 to 6, each rake 31 is formed, of a part, by a crossbar 33 comprising supports 34 of the scrub fingers 32 regularly distributed over said crossbar 33 and, on the other part, by a longitudinal handle 35 extending perpendicularly to said crossbar 33.

Dans l'exemple représenté sur les figures, chaque râteau 31 comporte trois doigts de décrassage 32.In the example shown in the figures, each rake 31 has three scouring fingers 32.

Selon une variante, chaque râteau 31 peut comporter un nombre de doigts de décrassage 32 supérieur ou intérieur à trois et chaque râteau 31 peut comporter un nombre différent de doigts de décrassage 32 en fonction de la surface du plongeur à couvrir et de la dimension de ce plongeur.According to a variant, each rake 31 can have a higher number of scrub fingers 32 or inside three and each rake 31 can have a different number of scouring fingers 32 in depending on the area of the diver to be covered and the dimension of this diver.

Ainsi que représenté à la Fig. 6, chaque support 34 comporte des lumières 36 pour le passage de boulons de fixation 37 d'un doigt de décrassage 32 sur le support 34 correspondant.As shown in FIG. 6, each support 34 includes lights 36 for the passage of fixing bolts 37 of a scouring finger 32 on the corresponding support 34.

Ces lumières 36 permettent de régler la position de chaque doigt de décrassage 32 sur le râteau 31.These lights 36 make it possible to adjust the position of each scouring finger 32 on the rake 31.

Le manche 35 de chaque râteau 31 possède une première extrémité 35a reliée à la barre transversale 33 du râteau 31 correspondant et une seconde extrémité 35b solidaire d'un axe transversal 38 de pivotement du râteau 31.The handle 35 of each rake 31 has a first end 35a connected to the crossbar 33 of the corresponding rake 31 and a second end 35b integral with a transverse axis 38 of pivoting of the rake 31.

Ainsi que représenté sur les figures 4 et 6, l'axe transversal 38 de chaque râteau 31 est relié à des moyens d'actionnement permettant de déplacer le râteau 31 ainsi que les doigts de décrassage 32 entre les deux positions.As shown in Figures 4 and 6, the transverse axis 38 of each rake 31 is connected to actuating means for moving the rake 31 as well as the scouring fingers 32 between the two positions.

Ces moyens d'actionnement du pivotement de chaque râteau 31 comprennent un vérin 39 par exemple hydraulique comportant un corps 39a monté pivotant sur un axe 40 relié par des éléments de fixation sur le bâti 21 et une tige de commande 39b dont l'extrémité libre est reliée de manière pivotante à l'axe transversal 38 du manche 35 correspondant, par au moins une biellette 41.These means for actuating the pivoting of each rake 31 includes a jack 39 for example hydraulic comprising a body 39a pivotally mounted on an axis 40 connected by fixing elements on the frame 21 and a control rod 39b whose free end is pivotally connected to the transverse axis 38 of the sleeve 35 corresponding, by at least one link 41.

Dans l'exemple de réalisation représenté sur les figures 4 à 6, la tige de commande 39b du vérin 39 est reliée à l'axe transversal 38 par deux biellettes parallèles 41 reliées entre elles par un flasque 45 (Figs. 4 et 6).In the embodiment shown on Figures 4 to 6, the control rod 39b of the cylinder 39 is connected to the transverse axis 38 by two rods parallel 41 connected to each other by a flange 45 (Figs. 4 and 6).

Chaque ensemble formé par un râteau 31, un axe transversal 38, un vérin 39 et un axe 40 est relié au bâti 21 par des éléments de support formés par exemple par des brides, respectivement 46, 47 et 48 (Figs. 5 et 6).Each set formed by a rake 31, a transverse axis 38, a jack 39 and an axis 40 is connected to the frame 21 by support elements formed for example by flanges, respectively 46, 47 and 48 (Figs. 5 and 6).

Chaque doigt de décrassage 32 forme avec l'horizontale un angle compris entre 30 et 60° lorsque le râteau 31 est en position active.Each scouring finger 32 forms with horizontal an angle between 30 and 60 ° when the rake 31 is in the active position.

En se reportant maintenant aux figures 3 et 7, on va décrire les moyens 50 de décrassage de l'espace intermédiaire 16 entre les plongeurs 12 et 13.Referring now to Figures 3 and 7, we will describe the means 50 for cleaning the space intermediate 16 between divers 12 and 13.

Ces moyens 50 de décrassage sont formés par au moins deux doigts de décrassage 51 opposés et déplaçables horizontalement.These scouring means 50 are formed by at least two opposing and movable scouring fingers 51 horizontally.

Chaque doigt de décrassage 51 de l'espace intermédiaire 16 est déplaçable par des moyens d'actionnement entre une position escamotée dans laquelle les doigts de décrassage 51 sont écartés de l'espace intermédiaire 16 et une position active dans laquelle les doigts de décrassage 51 sont en quasi-contact l'un contre l'autre et sont positionnés dans ledit espace intermédiaire 16.Each scouring finger 51 of the space intermediate 16 is movable by actuation means between a retracted position in which the scouring fingers 51 are separated from the intermediate space 16 and an active position in which the fingers scrub 51 are in quasi-contact one against the other and are positioned in said intermediate space 16.

Chaque doigt de décrassage 51 est monté sur un support 52 solidaire d'une tige 53 reliée aux moyens d'actionnement.Each scouring finger 51 is mounted on a support 52 secured to a rod 53 connected to the means actuation.

Comme pour les doigts de décrassage 32, le support 52 du doigt de décrassage 51 comporte des lumières, non représentées, pour le passage de boulons 54 de fixation du doigt de décrassage 51 sur son support 52.As with the scrub fingers 32, the support 52 of the scouring finger 51 includes lights, not shown, for passing bolts 54 for fixing the scouring finger 51 to its support 52.

Ces lumières ménagées sur le support 52 permettent de régler la position du doigt de décrassage 51 correspondant.These lights made on the support 52 adjust the position of the scrub finger 51 correspondent.

Ainsi que représenté à la figure 7, la tige 53 est montée coulissante dans un fourreau 54 supporté par le bâti 21.As shown in Figure 7, the rod 53 is slidably mounted in a supported sheath 54 by the frame 21.

Les moyens d'actionnement de chaque doigt de décrassage 51 sont formés par un vérin 55 par exemple hydraulique qui comporte, de manière classique, d'une part, un corps 55a relié au bâti 21 et, d'autre part, une tige de commande 55b reliée par son extrémité libre à la tige 53.The means of actuation of each finger scouring 51 are formed by a jack 55 for example hydraulics which conventionally includes a firstly, a body 55a connected to the frame 21 and, secondly, a control rod 55b connected by its free end to rod 53.

Selon une variante, chaque doigt de décrassage 51 peut être déplaçable par pivotement entre les deux positions.According to a variant, each scouring finger 51 can be moved by pivoting between the two positions.

Le bâti 21 est équipé à sa partie supérieure d'une trémie 17 qui permet de canaliser la gangue d'encrassement décollée des plongeurs 12 et 13 par les doigts de décrassage 32 et 51 dans un bac de récupération, non représenté, disposé à la base de ce bâti 21.The frame 21 is equipped at its upper part a hopper 17 which allows to channel the fouling gangue detachment of divers 12 and 13 by the fingers scrub 32 and 51 in a collecting tank, not shown, arranged at the base of this frame 21.

Ce bac de récupération est amovible et peut être vidé au moyen d'un engin de manutention. This recovery tray is removable and can be emptied by means of a handling device.

Les doigts de décrassage 32 et 51 sont par exemple en acier résistant à l'abrasion à haute température.The scouring fingers 32 and 51 are by example in high temperature abrasion resistant steel.

L'installation de décrassage fonctionne de la manière suivante.The scrub installation works from the next way.

Après une ou plusieurs opérations de traitement sous vide de l'acier liquide, l'opérateur procède à un décrassage simultané des plongeurs 12 et 13.After one or more processing operations under vacuum of liquid steel, the operator proceeds simultaneous scouring of divers 12 and 13.

Pour cela, après relevage de la cuve 1 et évacuation de la poche contenant l'acier liquide, l'opérateur commande par l'intermédiaire, par exemple d'une télécommande, le déplacement de l'ensemble constitué par le bâti 21 et le chariot 22 pour amener avec précision ce bâti 21 au-dessous des plongeurs 12 et 13.For this, after lifting the tank 1 and evacuation of the pocket containing the liquid steel, the operator commands through, for example a remote control, the movement of the assembly by the frame 21 and the carriage 22 to bring with precision this frame 21 below the plungers 12 and 13.

Les râteaux 31 des moyens 30 de décrassage sont en position relevée, comme représentée en traits mixtes sur la figure 4, et les doigts de décrassage 51 des moyens 50 de décrassage de l'espace intermédiaire 16 sont en position escamotée.Rakes 31 means 30 for cleaning are in the raised position, as shown in lines mixed in FIG. 4, and the scouring fingers 51 means 50 for cleaning the intermediate space 16 are in the retracted position.

Ensuite, l'opérateur commande la montée du bâti 21 par l'intermédiaire des vérins 26 pour que ce bâti 21 se déplace verticalement sur les rails 25 et que les râteaux 31 des moyens 30 de décrassage viennent se positionner au niveau de la partie inférieure des plongeurs 12 et 13.Then, the operator controls the rise of the frame 21 by means of the jacks 26 so that this frame 21 moves vertically on the rails 25 and that the rakes 31 of the scrubbing means 30 come position at the bottom of the divers 12 and 13.

Après la montée du bâti 21, l'opérateur commande les vérins 39 des râteaux 21 ce qui a pour effet de faire basculer ces râteaux 31 autour de l'axe transversal 38 en position active de telle manière que les doigts de décrassage 32 viennent se positionner contre la gangue d'encrassement déposée sur la surface externe des plongeurs 12 et 13.After the rise of the frame 21, the operator controls the rams 39 of the rakes 21 which has the effect to tilt these rakes 31 around the transverse axis 38 in the active position so that the scouring fingers 32 are positioned against the fouling matrix deposited on the external surface divers 12 and 13.

L'opérateur actionne les vérins 26 qui soulèvent progressivement le bâti 21 pour que les doigts de décrassage 32 raclent du bas vers le haut la gangue d'encrassement déposée sur les plongeurs 12 et 13.The operator actuates the jacks 26 which gradually lift the frame 21 so that the fingers scrub 32 scrape from bottom to top gangue fouling deposited on divers 12 and 13.

Le décrassage des plongeurs 12 et 13 par les doigts 32 est donc réalisé du bas vers le haut ce qui permet de maintenir le matériau réfractaire constituant ces plongeurs en compression.The cleaning of divers 12 and 13 by fingers 32 is therefore carried out from the bottom up which allows to maintain the refractory material constituting these compression divers.

En effet, les matériaux réfractaires ont une résistance dix fois supérieures en compression par rapport à la traction.In fact, refractory materials have a ten times greater resistance in compression by compared to traction.

L'opération de décrassage de la surface externe des plongeurs 12 et 13 peut être effectuée en une ou plusieurs passes selon l'importance de l'épaisseur de la gangue.The surface scrub operation external of divers 12 and 13 can be performed in one or several passes depending on the importance of the thickness of gangue.

Dans le cas d'un décrassage en plusieurs passes, les râteaux 31 sont relevés entre chaque passe et chaque passe de décrassage est réalisée du bas vers le haut de façon à maintenir le matériau réfractaire de ces plongeurs 12 et 13 en compression.In the case of multiple cleaning passes, the rakes 31 are raised between each pass and each cleaning pass is carried out from the bottom to the top so as to hold the refractory material of these plungers 12 and 13 in compression.

Le nombre de doigts de décrassage 32 est fonction du diamètre des plongeurs 12 et 13. Dans le cas de plongeurs de diamètre de 500 à 750mm, le nombre de doigts de décrassage 32 par plongeur est de neuf ou douze. Pour des plus petits plongeurs, six doigts de décrassage sont suffisants.The number of scouring fingers 32 is depending on the diameter of divers 12 and 13. In the case divers from 500 to 750mm in diameter, the number of scouring fingers 32 per plunger is nine or twelve. For smaller divers, six fingers scouring is sufficient.

A la fin du décrassage de la surface externe des plongeurs 12 et 13 et lorsque les doigts de décrassage 32 sont au niveau de la partie supérieure de ces plongeurs 12 et 13, l'opérateur commande les vérins 39 des râteaux 31 pour que les doigts de décrassage 32 s'écartent des plongeurs 12 et 13 et se positionnent en position relevée, comme représentée en traits mixtes sur la figure 4.At the end of the cleaning of the external surface divers 12 and 13 and when the scrub fingers 32 are at the top of these divers 12 and 13, the operator controls the cylinders 39 rakes 31 so that the scrub fingers 32 move away from divers 12 and 13 and position themselves in raised position, as shown in dashed lines on Figure 4.

Ensuite, pour réaliser le décrassage de l'espace intermédiaire 16 entre les plongeurs 12 et 13, l'opérateur actionne les vérins 55 afin que les doigts de décrassage 51 se déplacement horizontalement et viennent se positionner dans l'espace intermédiaire 16, comme représenté à la figure 3.Then, to carry out the cleaning of the intermediate space 16 between the plungers 12 and 13, the operator actuates the jacks 55 so that the fingers scrub 51 moves horizontally and are positioned in the intermediate space 16, as shown in figure 3.

Ensuite, l'opérateur actionne les vérins 26 de façon à descendre le bâti 21 ce qui provoque également la descente des doigts de décrassage 51 sur toute la hauteur de l'espace intermédiaire 16 entre les plongeurs 12 et 13.Then, the operator actuates the jacks 26 so as to lower the frame 21 which also causes the descent of the scouring fingers 51 over all the height of the intermediate space 16 between the divers 12 and 13.

Au cours de la descente de ces doigts de décrassage 51, la gangue d'encrassement déposée entre les plongeurs 12 et 13 est décollée.During the descent of these fingers of slag 51, the gangue of fouling deposited between divers 12 and 13 is lifted off.

La gangue d'encrassement décollée des plongeurs 12 et 13 est canalisée par la trémie 17 et tombe dans le bac de récupération.The gangue of fouling taken off by divers 12 and 13 is funneled through the hopper 17 and falls in the recycling bin.

L'ensemble des opération de l'installation de décrassage est réalisé à partir d'une commande centrale comme par exemple une radio commande et/ou un pupitre disposé sur le chariot 22 et le décrassage des plongeurs 12 et 13 est réalisé en deux ou trois minutes à partir du moment où le positionnement des doigts de décrassage est jugé comme correct par l'opérateur en fonction du taux d'encrassement rencontré.All the installation operations of scouring is carried out from a central control such as a radio control and / or a console arranged on the carriage 22 and the scouring of the divers 12 and 13 is completed in two or three minutes from from the moment the positioning of the scrub fingers is judged as correct by the operator according to the fouling rate encountered.

L'installation de décrassage selon l'invention permet d'opérer rapidement à forte température dans une zone de température où la gangue est encore sujette au fluage ce qui permet de faciliter son décollement, tout en donnant à l'opérateur des conditions de travail fortement améliorées.The scrub installation according to the invention allows rapid operation at high temperatures in a temperature zone where the gangue is still subject creep which makes it easier to detach, while giving the operator working conditions greatly improved.

L'opération de décrassage étant réalisée simultanément au niveau des plongeurs, le temps d'intervention est rapide ce qui permet de réaliser un gunitage des surfaces externe et interne des plongeurs 12 et 13 au moyen d'un machine adaptée et un séchage du produit de gunitage avant réutilisation de la cuve de traitement sous vide.The descaling operation being carried out simultaneously at the divers' level, the intervention time is fast which allows for a gunning of the external and internal surfaces of the divers 12 and 13 by means of a suitable machine and drying of the gunning product before reuse of the tank vacuum treatment.

A cet effet, le bâti 21 de l'installation de décrassage peut également être équipé de lances de gunitage qui permettent de projeter un produit sur les surfaces externe et interne des plongeurs 12 et 13.To this end, the frame 21 of the installation of scouring can also be fitted with lances gunning which allow to project a product on external and internal surfaces of divers 12 and 13.

D'autre part, le positionnement de chaque râteau 31 par rapport à la surface externe des plongeurs 12 et 13 et le positionnement des doigts de décrassage 51 de l'espace intermédiaire 16 sont réglables en fonction de l'épaisseur de la gangue d'encrassement et cela en agissant séparément sur la course des vérins 39 de positionnement des râteaux 31 et des vérins 55 de positionnement des doigts de décrassage 51.On the other hand, the positioning of each rake 31 in relation to the external surface of the divers 12 and 13 and the positioning of the scrub fingers 51 of the intermediate space 16 are adjustable as a function of the thickness of the fouling matrix and this by acting separately on the stroke of the cylinders 39 of positioning of rakes 31 and cylinders 55 of positioning of the scrub fingers 51.

De plus, le positionnement de chaque doigt de décrassage 32 et 51 sur son support 34 et 52 correspondant est réglable en fonction de l'usure de ces doigts de décrassage.In addition, the positioning of each finger scouring 32 and 51 on its corresponding support 34 and 52 is adjustable according to the wear of these fingers cleaning.

En cas d'ovalisation de la surface externe de l'un ou des deux plongeurs 12 et 13, le positionnement de chaque râteau 31 est réglable en fonction de cette ovalisation.In case of ovalization of the external surface one or two divers 12 and 13, positioning of each rake 31 is adjustable according to this ovalization.

L'installation selon l'invention permet de prolonger la durée de vie du matériau réfractaire constituant les plongeurs de la cuve de traitement et de pouvoir réaliser les différentes opérations de manière sûre et rapide et d'améliorer les conditions de travail de l'opérateur.The installation according to the invention makes it possible to extend the service life of refractory material constituting the plungers of the treatment tank and ability to perform different operations in a way safe and fast and improve working conditions operator.

De plus, la fréquence des opérations de décrassage peut être augmentée au bénéfice de la productivité de la cuve de traitement sous vide.In addition, the frequency of operations of scouring can be increased for productivity of the vacuum treatment tank.

Claims (14)

  1. Installation for deskulling the tubular nozzles (12, 13) made of refractory material of a vacuum treating vessel (I) for steel melts including a vessel bottom supporting tile nozzles (12, 13) arranged vertically and delimiting a buffer space (16) between them the installation including a frame (21) which can be moved horizontally and vertically and including, on its upper part, means (30) of simultaneous scraping from bottom to top and of the external surface of the said nozzles (12, 13) <characterised by the scraping means being> formed, for each of the said nozzles (12, 13), by rakes (31) fitted with deskulling fingers (32) distributed according to the circumference and movable by operating means (35, 41) between a retracted position in which the fingers (32) of the rakes (31) are removed from the external surfaces of the nozzles (12, 13), and an active position in which the fingers (32) of the rakes (31) are in contact with the external surface of the said nozzles (12, 13) and in that each rake (31) is formed by a transversal bar (33) including supports (34) for the deskulling fingers (32) and by a longitudinal shaft (35) extending perpendicular to the said bar (33), one end (35a) of this shaft (35) being connected to the said bat (33) and a second end (35b) of the shaft (35) being integral with a lateral pivoting axis (38) for the said rake (31), connected to the operating means (39, 41).
  2. Installation according to claim 1, characterised by the fiame (21) including, on its top part, means (50) for deskulling the buffer space (16) between the said nozzles (12, 13).
  3. Installation according to one of claims 1 and 2, characterised by the frame (21) being fitted with a means (22, 23) of horizontal movement to guide the said frame (21) under the said nozzles (12, 13).
  4. Installation according to one of claims 1 and 2, characterised by the frame (21) being fitted with means (24, 25, 26) of vertical movement to guide the scraping means (30) to the level of the said nozzles (12, 13).
  5. Installation according to claim 1, characterised by each rake (31) being movable by longitudinal sliding between the two positions.
  6. Installation according to claim 1, characterised by each rake (31) being movable by pivoting between the two positions.
  7. Installation according to claim 1, characterised by the operating methods for pivoting each rake (31) including a jack (39), hydraulic for example, containing a barrel (39a) mounted pivoting on an axis (40) and control rod (39b) whose free end is connected to the lateral axis (38) of the corresponding shaft (35) by at least one rod (41).
  8. Installation according to claim 1, characterised by each deskulling finger (32) forming with the horizontal an angle between 30 and 60°.
  9. Installation according to claim 2, characterised by the means (50) for deskulling the buffer space (16) between the nozzles (12, 13) including at least two opposing deskulling fingers (51) movable by operating means (55) between a retracted position in which the deskulling fingers (51) are removed from the buffer space (16) and an active position in which the deskulling fingers (51) are positioned in the said buffer space (16).
  10. Installation according to claim 9, characterised by each finger (51) for deskulling the buffer space (16) being mounted on a support (52) movable by sliding in a sleeve (54) of a rod (53) connected to the operating means (55).
  11. Installation according to any of claims 1 to 10, characterised by the position of each deskulling finger (32, 51) on its support (34, 52) being adjustable.
  12. Installation according to any one of claims 1 to 4, characterised by the frame (21) including, on its top part, a hopper (17).
  13. Installation according to any one of claims I to 4, characterised by the frame (21) including a drain pan for the clogging gangue removed from the nozzles (12, 13).
  14. Installation according to any one of claims 1 to 4, characterised by the frame (21) being fitted with pipes for guniting the external and internal surfaces of the nozzles (12, 13).
EP97402772A 1996-11-22 1997-11-18 Installation for deskulling the nozzles of a vacuum treating vessel for steel melts Expired - Lifetime EP0844310B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9614326A FR2756200B1 (en) 1996-11-22 1996-11-22 INSTALLATION FOR CLEANING THE DIVERS OF A LIQUID STEEL VACUUM TREATMENT TANK
FR9614326 1996-11-22

Publications (2)

Publication Number Publication Date
EP0844310A1 EP0844310A1 (en) 1998-05-27
EP0844310B1 true EP0844310B1 (en) 2001-10-10

Family

ID=9497930

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97402772A Expired - Lifetime EP0844310B1 (en) 1996-11-22 1997-11-18 Installation for deskulling the nozzles of a vacuum treating vessel for steel melts

Country Status (5)

Country Link
EP (1) EP0844310B1 (en)
AT (1) ATE206768T1 (en)
DE (1) DE69707245T2 (en)
ES (1) ES2166963T3 (en)
FR (1) FR2756200B1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE20022375U1 (en) * 2000-06-09 2001-08-09 SMS Mevac GmbH, 45141 Essen Trunk cleaning device for vacuum degassing systems
DE102007040882A1 (en) * 2007-08-29 2009-03-05 Sms Mevac Gmbh Cleaning device for dip tubes or probes of vacuum degassing plants

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5819446A (en) * 1981-07-25 1983-02-04 Nisshin Steel Co Ltd Removing device for slag in rh furnace or the like
GB8331152D0 (en) * 1983-11-22 1983-12-29 Henderson & Co Ltd John M Vessel nozzle cleaning apparatus
JPS62151260A (en) * 1985-12-25 1987-07-06 Kobe Steel Ltd Device for removing deposit from molten metal immersion pipe
JPH0632842B2 (en) * 1989-04-28 1994-05-02 黒崎窯業株式会社 Equipment for removing deposits from immersion pipes in molten metal processing equipment
JPH0645820B2 (en) * 1989-12-28 1994-06-15 黒崎窯業株式会社 Equipment for removing molten steel suction pipe in vacuum degassing equipment

Also Published As

Publication number Publication date
FR2756200A1 (en) 1998-05-29
DE69707245T2 (en) 2002-06-27
ES2166963T3 (en) 2002-05-01
FR2756200B1 (en) 1999-04-02
DE69707245D1 (en) 2001-11-15
EP0844310A1 (en) 1998-05-27
ATE206768T1 (en) 2001-10-15

Similar Documents

Publication Publication Date Title
EP0192019A1 (en) Apparatus for introducing and changing a pouring tube
FR2460027A1 (en) PROCESS FOR HANDLING COMBUSTIBLE ASSEMBLIES AND PENS WHEN RECHARGING A NUCLEAR REACTOR
FR2535835A1 (en) TILTING ARC OVEN
EP0675769B1 (en) Method and device for cleaning solid elements
CA1112404A (en) System for slagging off pouring ladles
EP0844310B1 (en) Installation for deskulling the nozzles of a vacuum treating vessel for steel melts
EP0767843B1 (en) Method and device for directly feeding liquid metal from a ladle into an electric furnace
EP0838540A1 (en) Process for changing spent anodes in Aluminium-Electrolysis vats and apparatus for collecting emitted gases during this process
CA2632845C (en) Method for removing anode residues attached to spent anodes coming from melt bath electrolysis potlines
EP3114257A2 (en) System for carrying out operations linked to the use of cells of a facility for producing aluminium by means of electrolysis
FR2504663A1 (en) METHOD AND APPARATUS FOR LOADING AN OVEN
EP0079290A1 (en) Equipment for the temperature measurement and/or the sampling of a refining installation
FR2548819A1 (en) METHOD AND DEVICE FOR CHARGING A METALLIC CONTAINER OF A MIXED VITREOUS MASS CONTAINING VERY RADIOACTIVE FISSION PRODUCTS
EP0234140A1 (en) Cleaning device for anode holes used in the aluminium industry
FR2521168A1 (en) IMPROVED PROCESS FOR REMOVING THE ECUME FROM A LEAN AND LEVER REFINING CRUCIBLE USING THE SAME
EP0562913B1 (en) Vessel containing several separated beds of solid material dischargeable by gravity without mixing of material
EP0501173A1 (en) Process and apparatus for treating steel-making slags
FR2668026A1 (en) APPARATUS FOR HARVESTING AND PROCESSING RAW MATERIALS, ADVANTAGEALLY PLANT WITHOUT TRANSHIPMENT.
FR3032456B1 (en) SERVICE MACHINE FOR OPERATING AN ALUMINUM PRODUCTION FACILITY
EP3903057B1 (en) Walking beam furnace for continuously discharging and shredding scale
FR2674946A1 (en) Electric furnace for metal production
FR2787871A1 (en) Machine for automatic lining of crucibles with refractory material for induction heating furnaces
EP4352413A1 (en) Device for feeding a container for an installation for the heat treatment of waste
FR2588574A1 (en) Device for breaking the points of Soederberg anodes
FR2476114A1 (en) Coke oven charging trolley - which carries mechanically driven scrapers removing carbonaceous deposits from oven charging holes and their lids

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

Kind code of ref document: A1

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

AX Request for extension of the european patent

Free format text: AL;LT;LV;RO;SI

17P Request for examination filed

Effective date: 19981029

AKX Designation fees paid

Free format text: AT BE CH DE DK ES FR GB IT LI LU NL SE

RBV Designated contracting states (corrected)

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

17Q First examination report despatched

Effective date: 19991105

RTI1 Title (correction)

Free format text: INSTALLATION FOR DESKULLING THE NOZZLES OF A VACUUM TREATING VESSEL FOR STEEL MELTS

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

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 DK ES FR GB IT LI LU NL SE

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

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20011010

Ref country code: GB

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20011010

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20011010

REF Corresponds to:

Ref document number: 206768

Country of ref document: AT

Date of ref document: 20011015

Kind code of ref document: T

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REF Corresponds to:

Ref document number: 69707245

Country of ref document: DE

Date of ref document: 20011115

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

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20020110

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20020110

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
GBV Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed]

Effective date: 20011010

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2166963

Country of ref document: ES

Kind code of ref document: T3

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: CH

Payment date: 20061016

Year of fee payment: 10

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

Ref country code: DE

Payment date: 20061108

Year of fee payment: 10

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

Ref country code: ES

Payment date: 20061113

Year of fee payment: 10

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

Ref country code: LU

Payment date: 20061114

Year of fee payment: 10

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

Ref country code: BE

Payment date: 20061128

Year of fee payment: 10

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

Ref country code: IT

Payment date: 20061130

Year of fee payment: 10

BERE Be: lapsed

Owner name: *PROSERTEC

Effective date: 20071130

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

Ref country code: LI

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

Effective date: 20071130

Ref country code: CH

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

Effective date: 20071130

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: BE

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

Effective date: 20071130

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

Ref country code: DE

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

Effective date: 20080603

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

Ref country code: FR

Payment date: 20061013

Year of fee payment: 10

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20080930

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20071119

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

Ref country code: FR

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

Effective date: 20071130

Ref country code: ES

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

Effective date: 20071119

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: 20071118

Ref country code: IT

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

Effective date: 20071118