EP0170585A1 - Temperature-homogenizing device for continuously moving metallic products - Google Patents
Temperature-homogenizing device for continuously moving metallic products Download PDFInfo
- Publication number
- EP0170585A1 EP0170585A1 EP85401464A EP85401464A EP0170585A1 EP 0170585 A1 EP0170585 A1 EP 0170585A1 EP 85401464 A EP85401464 A EP 85401464A EP 85401464 A EP85401464 A EP 85401464A EP 0170585 A1 EP0170585 A1 EP 0170585A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- inductors
- products
- zone
- active face
- temperature
- 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.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
- F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
- F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
- F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
- F27B9/201—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace walking beam furnace
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
- F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
- F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
- F27B9/22—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace on rails, e.g. under the action of scrapers or pushers
Definitions
- the present invention relates to the homogenization in temperature of metal products, in particular steel slabs, intended for rolling and having previously been subjected to this effect to a not perfectly homogeneous heating.
- thermal equalization zone Another solution consists in placing the heated products in the end portion of the unheated oven (so-called thermal equalization zone) so as to allow a better distribution of temperatures throughout the mass of the products.
- thermal equalization zone This process is quite slow and homogenization is only acquired at the expense of productivity or the size of the installation and at the cost of significant additional energy expenditure.
- the object of the present invention is to provide a solution which ensures at all points of the reheated product, a uniform temperature which is sufficient for the rolling operation, while avoiding the drawbacks of the aforementioned known solutions.
- the subject of the invention is a device for the temperature homogenization of moving metal products, in particular steel slabs, intended for lami swimming and previously warmed up in the heating zone of a reheating furnace having, following this heating zone, a thermal equalization zone, device characterized in that it is constituted by a plurality of inductors polyphase static magnetic field, elongated, which are placed in the thermal equalization zone of the reheating oven, parallel to themselves and in the extension of the support members of the products in movement from the heating zone, and the active face of the inductors, facing the products, has a width at least equal to the width of said support members, preferably between 1 and 4 times this width and more preferably equal to approximately 3 times this width.
- the conductors with which the inductors are fitted are oriented perpendicular to the direction of travel of the products.
- the present invention recommends selective inductive heating, located in the temperature equalization zone of the reheating oven, and located under the predetermined parts of the metal product which constitute the black traces.
- the location of the inductors in the extension of the metal product support rails guarantees their permanent arrangement with regard to the black traces which it is desired to eliminate.
- polyphase static inductors with a sliding field of elongated shape is particularly suitable because they make it possible to locally generate large induced currents, and therefore, a concentrated calorific contribution and localized at the places of the product that one wants to heat.
- thermal map of a "black trace” is pre generally feels as a family of relatively deep sinusoidal isotherms in the section of the metal.
- the spatial distribution of the power induced in the product by a sliding field inductor tends precisely to follow such a thermal profile.
- the width of the active face of the inductors is preferably in a ratio of 3 to 1 (or approaching) with the width of the support members. Beyond a ratio of 4 to 1, a non-negligible part of the induced power is unnecessarily injected at the periphery of the black trace, while below a ratio of 1 to 2, the inductor becomes undersized for the purpose of erasing the black traces.
- the invention has a decisive economic interest.
- demand is now shifting towards metallic products having particular mechanical characteristics, in particular of resilience and weldability, which require a very precise control of the grain size in the metal.
- One of the means of obtaining such characteristics consists in carrying out a so-called "low temperature” reheating, that is to say in baking the metal products at around 950 ° C. (instead of 1100 - 1200 ° C. as is usually does).
- this process while being energy efficient, requires precise control of the heating of the product.
- the device according to the invention which guarantees homogeneous heating within the metal, makes it possible to envisage the feasibility of reheating known as "at low temperature”.
- the slabs 3 are joined by their small lateral face so as to form a continuous sheet which moves from left to right in the direction indicated by the arrow F, using a pusher symbolized in 1 at the entrance 2 of the oven.
- the slabs thus travel slowly in a straight line through the oven from inlet 2 to outlet 4 where they are unloaded one by one on an inclined plane 5 which deposits them on a path with transport rollers 6 for their routing to the rolling plant (not shown).
- the oven comprises two thermal zones: a first zone 7 called “heating” with a length of about 18 m, in the upstream part of the oven and a second zone 8, called “equalization” with a length of 12 m approximately, in the downstream part of the oven.
- the heating zone 7 is conventionally composed of a first enclosure 7 ′, called the preheating of cold products, followed by a second enclosure 7 ′′ ensuring the heating of the preheated products to their nominal temperature.
- the slabs 3 are placed on the wear strip of metal slides 9 internally cooled by circulation of water. These slides 9, 20 cm wide, spaced from each other by a distance of the order of 1.5 m, form a parallel network oriented in the direction of movement of the slabs 3.
- the heating zone also includes front burners 10 and 11 respectively arranged in the upper and lower parts of the oven.
- the equalization zone 8 can also be equipped with front burners 10 ′, but only for the purpose of think of the heat losses that occur through the walls of the oven.
- the fumes produced in the oven flow against the current of the slabs 3 as far as the vicinity of the oven door where they are evacuated by a chimney 12.
- the slab-slide contact slows down the rapid rise in temperature of the slab 3 at this point and causes the formation of cold marks or "black marks".
- the slabs 3 are placed on a solid hearth 13 made of refractory material.
- This in accordance with the invention, is fitted with inductors with a sliding magnetic field 14 of elongated shape.
- These inductors 14 are placed in the extension of the slides 9 at the rate of one inductor per slide, and extend, in the example under consideration, over the entire length of the equalization zone 8.
- the active face 15 of the inductors placed opposite the hearth 13 has a length of 6 m and a width of approximately 50 cm.
- the inductor 14 is of planar structure and comprises a laminated magnetic yoke 16 having on the active face 15 regularly spaced parallel notches 17 serving as housing for conductors 18, formed of rectangular hollow copper bars to allow an internal circulation of a cooling fluid.
- the heads of the coils protruding laterally from the magnetic yoke are shown diagrammatically in 19 and 19 ′ and folded down to reduce their size under the floor 13.
- the conductors are adequately connected to a three-phase industrial frequency power supply (not shown) to produce a mobile magnetic field sliding along the longitudinal axis of the inductor.
- these inductors 14 are put in place under the sole 13 in the extension of the slides 9. In this way, the black traces 20 generated locally in the slabs 3 in contact with these slides, naturally come to pass above the inductors during the progression of the slabs in the thermal equalization zone 8.
- an insert 21 made of a refractory material with high thermal insulating properties (for example of fibrous refractory based on alumina) was housed in a recess 22 made for this purpose on the underside of the sole. 13 above the inductor 14.
- the role of this insert is to reinforce the thermal protection of the inductor 14 with respect to the heat given off by the slab 3.
- the action of the inductors 14 can be regulated in the usual way, for example by acting on the intensity of the excitation current, or on its frequency.
- An advantageous variant consists in providing a curved active face of the inductor.
- Such an arrangement makes it possible to increase the power induced in the center and to reduce it at both edges due of the variation thus obtained of the air gap according to the width of the active face 15.
- This arrangement may have an advantage insofar as the spatial distribution of the heating power induced in the slab 3 thus tends to approach the profile even more sinusoidal thermal effect of the "black trace" 20.
- inductor can be envisaged to provide a curved active face, by giving, for example, a semi-cylinder structure, or in the form of a circular sector to the inductor. .
- the sliding direction of the magnetic field can be modified according to the orientation of the busbars.
- a transverse arrangement of the conductive bars 18 that is to say perpendicular to the direction of travel of the slabs 3) was used.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
- General Induction Heating (AREA)
- Metal Rolling (AREA)
- Devices That Are Associated With Refrigeration Equipment (AREA)
- Tunnel Furnaces (AREA)
- Soil Working Implements (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Control And Other Processes For Unpacking Of Materials (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Disintegrating Or Milling (AREA)
- Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
- Control Of Heat Treatment Processes (AREA)
- Resistance Heating (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Abstract
Description
La présente invention a trait à l'homogénéisation en température de produits métalliques, notamment des brames d'acier, destinés au laminage et ayant préalablement été soumis à cet effet à un réchauffage non parfaitement homogène.The present invention relates to the homogenization in temperature of metal products, in particular steel slabs, intended for rolling and having previously been subjected to this effect to a not perfectly homogeneous heating.
Avant d'être laminés, il est en premier lieu nécessaire de porter les produits métalliques à une température adéquate, et en second lieu, souhaitable que cette température soit aussi uniforme que possible dans toute la masse de ce produit. Ce second objectif est particulièrement difficile à réaliser dans le cas de produits de taille importante tels que les brames.Before being rolled, it is first necessary to bring the metal products to an adequate temperature, and secondly, desirable that this temperature be as uniform as possible throughout the mass of this product. This second objective is particularly difficult to achieve in the case of large products such as slabs.
Dans les fours industriels à flamme habituels, destinés au réchauffage des brames avant laminage, qu'ils soient du type "poussant" (brames jointives) ou à "longerons mobiles" (brames séparées), les brames se déplacent sur une sole constituée par des organes de support disposés parallèlement dans la direction du défilement des brames. On rappelle que ces organes de support sont constitués, soit uniquement par des glissières fixes (fours poussants), soit par un groupe de barres fixes et un autre groupe de longerons mobiles, ces derniers assurant le déplacement des brames à l'intérieur du four (four à longerons). A l'endroit du contact brameorganes de support, on constate habituellement la présence de parties plus froides que l'ensemble de la brame et pouvant parfois traverser toute l'épaisseur du produit. Ces parties plus froides se manifestent superficiellement par une coloration plus foncée que le reste du produit. Pour cette raison, on les désigne généralement par "traces noires". Un tel phénomène se présente en particulier dans les fours destinés au réchauffage des produits épais où le chauffage s'effectue non seulement par la voûte mais également par le fond, sous les produits, car, d'une part, il est nécessaire de refroidir intérieurement les organes de support et, d'autre part, l'endroit du contact brame-organes de support n'est pas directement exposé à la chaleur, qui se transmet en grande partie par rayonnement.In conventional industrial flame ovens, intended for reheating slabs before rolling, whether they are of the "pushing" type (contiguous slabs) or of "movable beams" (separate slabs), the slabs move on a hearth formed by support members arranged parallel in the direction of travel of the slabs. It will be recalled that these support members are constituted, either only by fixed slides (pushing ovens), or by a group of fixed bars and another group of mobile beams, the latter ensuring the movement of the slabs inside the oven ( beam oven). At the point of contact with the support bodies, we usually observe the presence of parts that are colder than the whole of the support and which can sometimes cross the entire thickness of the product. These colder parts are superficially manifested by a darker coloring than the rest of the product. For this reason, they are generally designated by "black traces". Such a phenomenon occurs in particular in ovens intended for the reheating of thick products where the heating takes place not only by the vault but also by the bottom, under the products, because, on the one hand, it is necessary to cool internally the support members and, on the other hand, the location of the slab-support member contact is not directly exposed to the heat, which is largely transmitted by radiation.
La présence de ces traces noires est la cause de gradients de température locaux suffisamment importants pour engendrer des défauts métallurgiques dans le produit, et conduire à des surépaisseurs lors du laminage ultérieur.The presence of these black traces is the cause of local temperature gradients large enough to cause metallurgical defects in the product, and lead to extra thicknesses during subsequent rolling.
On peut songer à les atténuer en agissant, au niveau du laminoir, sur les jets d'eau destinés à débarrasser les produits en défilement de leur calamine. L'effet de refroidissement qui en résulte peut être adapté en vue de l'atténuation des traces noires, par exemple en refroidissant l'ensemble du produit à l'exclusion de ces zones plus froides. Toutefois, on se rend rapidement compte que cette méthode, de mise en oeuvre peu commode, offre difficilement les résultats souhaités et, de ce fait, n'est guère utilisée.We can consider mitigating them by acting, at the level of the rolling mill, on the water jets intended to rid the moving products of their scale. The resulting cooling effect can be adapted with a view to reducing black marks, for example by cooling the entire product to the exclusion of these colder zones. However, one quickly realizes that this method, of inconvenient implementation, hardly offers the desired results and, therefore, is hardly used.
Une autre solution consiste à faire séjourner les produits réchauffés dans la partie terminale du four non chauffée (zone dite d'égalisation thermique) de manière à permettre une meilleure répartition des températures dans toute la masse des produits. Cependant, ce procédé est assez lent et l'homogénéisation n'est acquise qu'au détriment de la productivité ou de la taille de l'installation et au prix de dépenses énergétiques supplémentaires non négligeables.Another solution consists in placing the heated products in the end portion of the unheated oven (so-called thermal equalization zone) so as to allow a better distribution of temperatures throughout the mass of the products. However, this process is quite slow and homogenization is only acquired at the expense of productivity or the size of the installation and at the cost of significant additional energy expenditure.
Une autre solution, qui, à la connaissance des inventeurs, n'a pas encore reçu d'application industrielle, consiste à placer dans le convoyeur à rouleaux à la sortie du four, un ou plusieurs inducteurs à champ magnétique glissant destinés à chauffer localement les brames aux endroits des traces ncires (FR A.76/35 635). Cette technique de chauffage inductif, certainement très élégante en soi, repose cependant sur une marche discontinue des inducteurs, ce qui impose la mise au point d'un système de détection des traces noires et des phases d'arrêt au défilement des brames lorsque les traces noires se trouvent au-dessus des inducteurs.Another solution, which, to the knowledge of the inventors, has not yet received industrial application, consists in placing in the roller conveyor at the outlet of the oven, one or more inductors with a sliding magnetic field intended to locally heat the slabs at places of black marks (FR A.76 / 35 635). This inductive heating technique, certainly very elegant in itself, is however based on a discontinuous operation of the inductors, which requires the development of a system for detecting black traces and stopping phases when the slabs pass when the traces black are above the inductors.
La présente invention a pour but de fournir une solution qui assure en tout point du produit réchauffé, une température homogène et suffisante pour l'opération de laminage, en évitant les inconvénients des solutions connues prémentionnées.The object of the present invention is to provide a solution which ensures at all points of the reheated product, a uniform temperature which is sufficient for the rolling operation, while avoiding the drawbacks of the aforementioned known solutions.
A cet effet, l'invention a pour objet un dispositif pour l'homogénéisation en température de produits métalliques en défilement, notamment des brames en acier, destinés au laminage et préalablement montés en température dans la zone de chauffage d'un four de réchauffage présentant, à la suite de cette zone de chauffage, une zone d'égalisation thermique, dispositif caractérisé en ce qu'il est constitué par une pluralité d'inducteurs statiques polyphasés à champ magnétique glissant, de forme allongée, qui sont placés dans la zone d'égalisation thermique du four de réchauffage, parallèlement à eux-mêmes et dans le prolongement des organes de support des produits en défilement de la zone de chauffage, et dont la face active des inducteurs, tournée en regard des produits, présente une largeur au moins égale à la largeur desdits organes de support, de préférence comprise entre 1 et 4 fois cette largeur et de préférence encore égale à 3 fois cette largeur environ.To this end, the subject of the invention is a device for the temperature homogenization of moving metal products, in particular steel slabs, intended for lami swimming and previously warmed up in the heating zone of a reheating furnace having, following this heating zone, a thermal equalization zone, device characterized in that it is constituted by a plurality of inductors polyphase static magnetic field, elongated, which are placed in the thermal equalization zone of the reheating oven, parallel to themselves and in the extension of the support members of the products in movement from the heating zone, and the active face of the inductors, facing the products, has a width at least equal to the width of said support members, preferably between 1 and 4 times this width and more preferably equal to approximately 3 times this width.
Conformément à une variante, les conducteurs dont sont équipés les inducteurs sont orientés perpendiculairement à la direction de défilement des produits.According to a variant, the conductors with which the inductors are fitted are oriented perpendicular to the direction of travel of the products.
Comme on le comprend, la présente invention préconise un chauffage inductif sélectif, situé dans la zone d'égalisation en température du four de réchauffage, et localisé sous les parties prédéterminées du produit métallique qui constituent les traces noires.As will be understood, the present invention recommends selective inductive heating, located in the temperature equalization zone of the reheating oven, and located under the predetermined parts of the metal product which constitute the black traces.
Le positionnement ainsi que la nature des moyens de chauffage choisis font du dispositif selon l'invention, un moyen de chauffage d'appoint efficace qui complète avantageusement celui qui est effectué dans la zone de chauffage proprement dite.The positioning as well as the nature of the heating means chosen make the device according to the invention, an efficient auxiliary heating means which advantageously complements that which is carried out in the heating zone proper.
En effet, la localisation des inducteurs dans le prolongement des glissières de support des produits métalliques garantit leur disposition permanente en regard des traces noires que l'on souhaite éliminer.Indeed, the location of the inductors in the extension of the metal product support rails guarantees their permanent arrangement with regard to the black traces which it is desired to eliminate.
En outre, le choix d'inducteurs statiques polyphasés à champ glissant de forme allongée est particulièrement approprié car ils permettent de générer localement des courants induits importants, et donc, un apport calorifique concentré et localisé aux endroits du produit que l'on veut chauffer.In addition, the choice of polyphase static inductors with a sliding field of elongated shape is particularly suitable because they make it possible to locally generate large induced currents, and therefore, a concentrated calorific contribution and localized at the places of the product that one wants to heat.
De plus, la carte thermique d'une "trace noire" se présente généralement sous la forme d'une famille d'isothermes sinusoïdales relativement profondes dans la section du métal. La répartition spatiale de la puissance induite dans le produit par un inducteur à champ glissant tend précisément à épouser un tel profil thermique.In addition, the thermal map of a "black trace" is pre generally feels as a family of relatively deep sinusoidal isotherms in the section of the metal. The spatial distribution of the power induced in the product by a sliding field inductor tends precisely to follow such a thermal profile.
A ce titre, il a pu être déterminé que, dans les conditions habituelles de marche des fours, la largeur de la face active des inducteurs est de préférence dans un rapport de 3 pour 1 (ou approchant) avec la largeur des organes de support. Au-delà d'un rapport de 4 pour 1, une part non négligeable de la puissance induite est inutilement injectée à la périphérie de la trace noire, alors qu'en-deçà d'un rapport de 1 pour 2, l'inducteur devient sous-dimensionné pour les besoins d'effacement des traces noires.As such, it could be determined that, under the usual operating conditions of ovens, the width of the active face of the inductors is preferably in a ratio of 3 to 1 (or approaching) with the width of the support members. Beyond a ratio of 4 to 1, a non-negligible part of the induced power is unnecessarily injected at the periphery of the black trace, while below a ratio of 1 to 2, the inductor becomes undersized for the purpose of erasing the black traces.
Par ailleurs, l'invention présente un intérêt économique déterminant. En effet, la demande s'oriente désormais vers des produits métalliques possédant des caractéristiques mécaniques particulières, notamment de résilience et de soudabilité, qui nécessitent une maîtrise très précise de la grosseur de grain dans le métal. Un des moyens d'obtenir de telles caractéristiques consiste à effectuer un réchauffage dit "à basse température", c'est-à-dire à défourner les produits métalliques à environ 950 °C (au lieu de 1100 - 1200 °C comme cela se fait habituellement). Bien entendu, ce procédé, tout en étant énergétiquement économique, nécessite un contrôle précis du réchauffage du produit. Le dispositif selon l'invention, qui garantit un chauffage homogène au sein du métal, permet d'envisager la faisabilité du réchauffage dit "à basse température".Furthermore, the invention has a decisive economic interest. In fact, demand is now shifting towards metallic products having particular mechanical characteristics, in particular of resilience and weldability, which require a very precise control of the grain size in the metal. One of the means of obtaining such characteristics consists in carrying out a so-called "low temperature" reheating, that is to say in baking the metal products at around 950 ° C. (instead of 1100 - 1200 ° C. as is usually does). Of course, this process, while being energy efficient, requires precise control of the heating of the product. The device according to the invention, which guarantees homogeneous heating within the metal, makes it possible to envisage the feasibility of reheating known as "at low temperature".
D'autres avantages et caractéristiques apparaîtront au vu de la description qui va suivre, donnée à titre d'exemple non limitatif, en référence aux planches de dessins annexées sur lesquelles :
- - la figure 1 représente une coupe schématique longitudinale d'un four poussant pour le réchauffage de brames en acier et équipé du dispositif selon l'invention ;
- - la figure 2 est un agrandissement de la partie référencée A du four exemplifiée sur la figure 1 et pourvue du dispositif selon l'invention ;
- - la figure 3 représente une coupe transversale selon le plan XX' de la figure 1 ou de la figure 2 ;
- - la figure 4 représente une variante de réalisation de l'invention selon une vue analogue à celle de la figure 3.
- - Figure 1 shows a schematic longitudinal section of a push furnace for reheating steel slabs and equipped with the device according to the invention;
- - Figure 2 is an enlargement of the part referenced A of the oven exemplified in Figure 1 and provided with the device according to the invention;
- - Figure 3 shows a cross section along the plane XX 'of Figure 1 or Figure 2;
- FIG. 4 represents an alternative embodiment of the invention according to a view similar to that of FIG. 3.
Dans le four poussant illustré sur la figure 1, les brames 3 sont jointives par leur petite face latérale de manière à former une nappe continue qui se déplace de gauche à droite dans le sens indiqué par la flèche F, à l'aide d'une pousseuse symbolisée en 1 à l'entrée 2 du four. Les brames défilent ainsi lentement en ligne droite au travers du four depuis l'entrée 2 jusqu'à la sortie 4 où elles sont défournées une à une sur un plan incliné 5 qui les dépose sur un chemin à rouleaux de transport 6 en vue de leur acheminement vers l'installation de laminage (non représentée).In the pushing furnace illustrated in FIG. 1, the
Le four comprend deux zones thermiques : une première zone 7 dite "de chauffage" d'une longueur de 18 m environ, dans la partie amont du four et une seconde zone 8, dite "d'égalisation" d'une longueur de 12 m environ, dans la partie aval du four.The oven comprises two thermal zones: a
La zone de chauffage 7 est composée classiquement d'une première enceinte 7', dite de préchauffage des produits froids, suivie d'une deuxième enceinte 7" assurant le chauffage des produits préchauffés jusqu'à leur température nominale.The
Dans cette zone de chauffage, les brames 3 sont posées sur la bande d'usure de glissières métalliques 9 refroidies intérieurement par circulation d'eau. Ces glissières 9, de 20 cm de large, espacées les unes des autres d'une distance de l'ordre de 1,5 m, forment un réseau parallèle orienté dans la direction de déplacement des brames 3. La zone de chauffage comporte également des brûleurs frontaux 10 et 11 respectivement disposés dans les parties supérieures et inférieures du four.In this heating zone, the
La zone d'égalisation 8 peut également être équipée de brûleurs frontaux 10', mais dans le but, uniquement, de compenser les pertes thermiques qui se produisent par les parois du four.The equalization zone 8 can also be equipped with
Les fumées produites dans le four circulent à contre- courant des brames 3 jusqu'au voisinage de la porte d'enfournement où elles sont évacuées par une cheminée 12.The fumes produced in the oven flow against the current of the
Comme il a été dit précédemment, le contact brame-glissière freine en cet endroit la montée rapide en température de la brame 3 et entraîne la formation de marques froides ou "traces noires".As mentioned above, the slab-slide contact slows down the rapid rise in temperature of the
Dans la zone d'égalisation 8 (ou d'homogénéisation en température), les brames 3 sont posées sur une sole pleine 13 en matériau réfractaire. Celle-ci, conformément à l'invention, est équipée d'inducteurs à champ magnétique glissant 14 de forme allongée. Ces inducteurs 14 sont placés dans le prolongement des glissières 9 à raison d'un inducteur par glissière, et s'étendent, dans l'exemple considéré, sur la totalité de la longueur de la zone d'égalisation 8. Dans cet exemple, la face active 15 des inducteurs placée en regard de la sole 13 présente une longueur de 6 m et une largeur d'environ 50 cm.In the equalization 8 (or temperature homogenization) zone, the
En se reportant aux figurés 2 et 3, on distingue l'aménagement réalisé dans la sole d'égalisation 13 pour la mise en place d'un inducteur 14 à champ glissant.Referring to FIGS. 2 and 3, a distinction is made between the arrangement made in the
Comme on peut le voir, l'inducteur 14 est de structure plane et comprend une culasse magnétique feuilletée 16 présentant sur la face active 15 des encoches parallèles régulièrement espacées 17 servant de logement à des conducteurs 18, formées de barres rectangulaires en cuivre creux pour permettre une circulation interne d'un fluide refroidissant. On a schématiquement représenté en 19 et 19' les têtes des bobines dépassant latéralement de la culasse magnétique et repliées vers le bas pour réduire leur encombrement sous la sole 13.As can be seen, the
Les conducteurs sont reliés de façon adéquate à une alimentation électrique triphasée de fréquence industrielle (non représentée) pour produire un champ magnétique mobile glissant selon l'axe longitudinal de l'inducteur.The conductors are adequately connected to a three-phase industrial frequency power supply (not shown) to produce a mobile magnetic field sliding along the longitudinal axis of the inductor.
Conformément à l'invention, ces inducteurs 14 sont mis en place sous la sole 13 dans le prolongement des glissières 9. De la sorte, les traces noires 20 générées localement dans les brames 3 au contact de ces glissières, viennent naturellement défiler au-dessus des inducteurs au cours de la progression des brames dans la zone 8 d'égalisation thermique.According to the invention, these
Dans l'exemple décrit, un insert 21 en un matériau réfractaire à propriétés élevées d'isolant thermique (par exemple en réfractaire fibreux à base d'alumine) a été logé dans un évidement 22 pratiqué à cet effet sur la face inférieure de la sole 13 au-dessus de l'inducteur 14. Cet insert a pour rôle de renforcer la protection thermique de l'inducteur 14 à l'égard de la chaleur dégagée par la brame 3.In the example described, an
Par ailleurs, pour augmenter le rendement de chauffage de l'inducteur 14, on a avantage à le rapprocher de la brame 3 d'une distance inférieure à l'épaisseur de la sole 13 afin de réduire l'entrefer (distance séparant la face active 5 de l'inducteur des brames 3).La figure 3 montre que ce résultat peut être obtenu aisément à l'aide d'un insert 2 à base concave, servant d'empreinte à l'inducteur 14.Furthermore, to increase the heating efficiency of the
En outre, l'action des inducteurs 14 peut être régulée de la façon habituelle, par exemple en agissant sur l'intensité du courant excitateur, ou sur sa fréquence.In addition, the action of the
L'expérience a montré que, dans le cas du four décrit ci-dessus,. pour "effacer" intégralement les traces noires dans des brames de 250 mm d'épaisseur et de 3,5 m de long sur 2 m de large, réchauffées à 950°C, on doit utiliser, avec une fréquence de 50 Hz du courant, une puissance de 58 kW/inducteur quand la production du four est de 85 t/h.Experience has shown that, in the case of the oven described above ,. to completely "erase" the black traces in slabs 250 mm thick and 3.5 m long by 2 m wide, heated to 950 ° C, it is necessary to use, with a frequency of 50 Hz of the current, a power of 58 kW / inductor when the oven production is 85 t / h.
Par contre, il faut induire une puissance de 220 kW/inducteur dans le cas où la production de ce four est de 160 t/h.On the other hand, it is necessary to induce a power of 220 kW / inductor in the case where the production of this oven is 160 t / h.
Il va de soi que l'invention n'est pas limitée à l'exemple décrit ci-dessus.It goes without saying that the invention is not limited to the example described above.
Une variante avantageuse consiste à ménager une face active bombée de l'inducteur.An advantageous variant consists in providing a curved active face of the inductor.
Une telle disposition permet d'accroître la puissance induite au centre et de la réduire aux deux bords en raison de la variation ainsi obtenue de l'entrefer selon la largeur de la face active 15. Cette disposition peut présenter un avantage dans la mesure où la répartition spaciale de la puissance induite de chauffage dans la brame 3 tend ainsi à se rapprocher plus encore du profil thermique sinusoidal de la "trace noire" 20.Such an arrangement makes it possible to increase the power induced in the center and to reduce it at both edges due of the variation thus obtained of the air gap according to the width of the
Par ailleurs, il est clair que d'autres variantes de structure de l'inducteur peuvent être envisagées pour ménager une face active bombée, en donnant, par exemple, une structure en demi-cylindre, ou en forme de secteur circulaire à l'inducteur.Furthermore, it is clear that other structural variants of the inductor can be envisaged to provide a curved active face, by giving, for example, a semi-cylinder structure, or in the form of a circular sector to the inductor. .
De même, la direction de glissement du champ magnétique peut être modifiée selon l'orientation des barres conductrices. Dans le cas d'exemples décrits ci-avant, on a utilisé une disposition transversale des barres conductrices 18 (c'est-à-dire perpendiculaires à la direction de défilement des brames 3).Likewise, the sliding direction of the magnetic field can be modified according to the orientation of the busbars. In the case of the examples described above, a transverse arrangement of the conductive bars 18 (that is to say perpendicular to the direction of travel of the slabs 3) was used.
On peut très bien opter pour une disposition longitudinale des barres conductrices (c'est-à-dire parallèles à la direction de défilement des brames 3) de manière à procurer un champ qui glisse suivant une direction perpendiculaire à celle du déplacement de la brame 3. Une telle variante a été représentée sur la figure 4. La différence essentielle entre cette variante et la forme de réalisation décrite précédemment réside dans le fait que les barres conductrices 18' sont disposées dans des encoches longitudinales 17' parallèles cette fois à la direction de défilement des brames 3 et la culasse magnétique 16' de l'inducteur 14' est feuilletée selon des plans de coupe parallèles au plan de la figure.One can very well opt for a longitudinal arrangement of the busbars (that is to say parallel to the direction of travel of the slabs 3) so as to provide a field which slides in a direction perpendicular to that of the movement of the
De plus, en ce qui concerne la disposition des inducteurs dans le rôle d'égalisation du four, il va de soi que d'autres variantes que celle décrite auparavant sont envisageables. Notamment, on peut songer à répartir les inducteurs à différents endroits dans la sole d'égalisation, chaque inducteur étant bien entendu disposé dans le prolongement des glissières.In addition, with regard to the arrangement of the inductors in the role of equalization of the furnace, it goes without saying that other variants than that described above can be envisaged. In particular, one can think of distributing the inductors at different locations in the equalization hearth, each inductor being of course arranged in the extension of the slides.
En outre, on comprend aisément que plus la longueur des inducteurs augmente, moins la puissance surfacique de chauffe de chaque inducteur doit être importante; A la limite, on peut prévoir des inducteurs qui fassent toute la longueur de la sole d'égalisation.In addition, it is easily understood that the longer the length of the inductors increases, the less the surface heating power of each inductor must be significant; Ultimately, we can provide inductors that run the entire length of the leveling deck.
Claims (7)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT85401464T ATE34832T1 (en) | 1984-07-27 | 1985-07-17 | DEVICE FOR HOMOGENIZING THE TEMPERATURE OF METAL WORKPIECES IN CONTINUOUS MOVEMENT. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR8412228A FR2568359B1 (en) | 1984-07-27 | 1984-07-27 | DEVICE FOR THE INDUCTIVE TEMPERATURE HOMOGENEIZATION OF RUNNING METAL PRODUCTS |
FR8412228 | 1984-07-27 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0170585A1 true EP0170585A1 (en) | 1986-02-05 |
EP0170585B1 EP0170585B1 (en) | 1988-06-01 |
Family
ID=9306724
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP85401464A Expired EP0170585B1 (en) | 1984-07-27 | 1985-07-17 | Temperature-homogenizing device for continuously moving metallic products |
Country Status (12)
Country | Link |
---|---|
US (1) | US4745252A (en) |
EP (1) | EP0170585B1 (en) |
JP (1) | JPS6144127A (en) |
KR (1) | KR920001610B1 (en) |
AT (1) | ATE34832T1 (en) |
AU (1) | AU574208B2 (en) |
BR (1) | BR8503562A (en) |
CA (1) | CA1251640A (en) |
DE (1) | DE3563115D1 (en) |
ES (1) | ES8608665A1 (en) |
FR (1) | FR2568359B1 (en) |
ZA (1) | ZA855378B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1994008190A1 (en) * | 1992-10-05 | 1994-04-14 | Acon Finland Oy Ltd | Method and apparatus for improving the performance of a heating furnace for metal slabs |
NL1010415C2 (en) * | 1998-10-28 | 2000-05-01 | Acon Europ Limited | Apparatus for heating a steel sheet before it is rolled out. |
EP2225401A2 (en) * | 2007-12-19 | 2010-09-08 | Nu-Iron Technology, LLC | System and method for producing metallic iron |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2633792B2 (en) * | 1993-03-31 | 1997-07-23 | 本田技研工業株式会社 | High frequency heating method and apparatus |
US6110805A (en) * | 1997-12-19 | 2000-08-29 | Micron Technology, Inc. | Method and apparatus for attaching a workpiece to a workpiece support |
FR2829232B1 (en) * | 2001-09-06 | 2004-08-20 | Air Liquide | METHOD FOR IMPROVING THE TEMPERATURE PROFILE OF AN OVEN |
US6841763B1 (en) * | 2003-08-27 | 2005-01-11 | Ksp Technologies Corp. | Heat induction workstation |
ITUB20169915A1 (en) * | 2016-01-12 | 2017-07-12 | Siti B & T Group Spa | Kiln for ceramics with improved efficiency |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1408638A (en) * | 1964-09-23 | 1965-08-13 | Ofenbau Union Gmbh | Solid hearth for industrial furnaces used for the heat treatment of metallurgical products |
DE1236545B (en) * | 1965-12-09 | 1967-03-16 | Bbc Brown Boveri & Cie | Method and device for the elimination of cool shadows on hot material heated in a heating furnace |
US3342468A (en) * | 1964-06-30 | 1967-09-19 | United States Steel Corp | Apparatus for removing cold skid marks from objects |
DE1268644B (en) * | 1965-12-17 | 1968-05-22 | Didier Werke Ag | Heating beam for the equalizing hearth of a pusher oven |
FR2417737A1 (en) * | 1978-02-16 | 1979-09-14 | Stein Surface | Heating oven with conveyor and induction coils - has photoelectric cells to monitor appearance of black streaks |
FR2445085A1 (en) * | 1978-12-22 | 1980-07-18 | Courdille Rene | INDUCTION HEATING SYSTEM FOR FLAT METALLURGICAL PRODUCTS |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3469052A (en) * | 1967-09-01 | 1969-09-23 | Westinghouse Electric Corp | Heating apparatus for metal workpieces |
US3471673A (en) * | 1968-02-19 | 1969-10-07 | United States Steel Corp | Apparatus for inductively heating a traveling metal slab |
US3715556A (en) * | 1970-10-05 | 1973-02-06 | Park Ohio Industries Inc | Slab heating method and apparatus |
US4087238A (en) * | 1976-09-13 | 1978-05-02 | United States Steel Corporation | Method for enhancing the heating efficiency of continuous slab reheating furnaces |
FR2372402A1 (en) * | 1976-11-25 | 1978-06-23 | Siderurgie Fse Inst Rech | Homogenising of the temperature of hot metal slabs - by means of a magnetic field |
US4289944A (en) * | 1977-12-19 | 1981-09-15 | Reese Thurston F | Apparatus for reheating, storing and conveying cast bars |
JPS57168489A (en) * | 1981-04-07 | 1982-10-16 | Mitsubishi Electric Corp | Stationary induction heater |
-
1984
- 1984-07-27 FR FR8412228A patent/FR2568359B1/en not_active Expired
-
1985
- 1985-07-17 ZA ZA855378A patent/ZA855378B/en unknown
- 1985-07-17 DE DE8585401464T patent/DE3563115D1/en not_active Expired
- 1985-07-17 AT AT85401464T patent/ATE34832T1/en not_active IP Right Cessation
- 1985-07-17 EP EP85401464A patent/EP0170585B1/en not_active Expired
- 1985-07-23 AU AU45250/85A patent/AU574208B2/en not_active Ceased
- 1985-07-24 JP JP60163792A patent/JPS6144127A/en active Pending
- 1985-07-26 BR BR8503562A patent/BR8503562A/en not_active IP Right Cessation
- 1985-07-26 ES ES545584A patent/ES8608665A1/en not_active Expired
- 1985-07-26 CA CA000487732A patent/CA1251640A/en not_active Expired
- 1985-07-27 KR KR1019850005401A patent/KR920001610B1/en active IP Right Grant
-
1986
- 1986-10-03 US US06/914,530 patent/US4745252A/en not_active Expired - Fee Related
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3342468A (en) * | 1964-06-30 | 1967-09-19 | United States Steel Corp | Apparatus for removing cold skid marks from objects |
FR1408638A (en) * | 1964-09-23 | 1965-08-13 | Ofenbau Union Gmbh | Solid hearth for industrial furnaces used for the heat treatment of metallurgical products |
DE1236545B (en) * | 1965-12-09 | 1967-03-16 | Bbc Brown Boveri & Cie | Method and device for the elimination of cool shadows on hot material heated in a heating furnace |
DE1268644B (en) * | 1965-12-17 | 1968-05-22 | Didier Werke Ag | Heating beam for the equalizing hearth of a pusher oven |
FR2417737A1 (en) * | 1978-02-16 | 1979-09-14 | Stein Surface | Heating oven with conveyor and induction coils - has photoelectric cells to monitor appearance of black streaks |
FR2445085A1 (en) * | 1978-12-22 | 1980-07-18 | Courdille Rene | INDUCTION HEATING SYSTEM FOR FLAT METALLURGICAL PRODUCTS |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1994008190A1 (en) * | 1992-10-05 | 1994-04-14 | Acon Finland Oy Ltd | Method and apparatus for improving the performance of a heating furnace for metal slabs |
US5609785A (en) * | 1992-10-05 | 1997-03-11 | Acon Finland Oy Ltd. | Method and apparatus for improving the performance of a heating furnace for metal slabs |
NL1010415C2 (en) * | 1998-10-28 | 2000-05-01 | Acon Europ Limited | Apparatus for heating a steel sheet before it is rolled out. |
WO2000025077A1 (en) * | 1998-10-28 | 2000-05-04 | Acon Europe Limited | Device for heating a steel plate before it is rolled out |
GB2347486A (en) * | 1998-10-28 | 2000-09-06 | Acon Europ Limited | Device for heating a steel plate before it is rolled out |
EP2225401A2 (en) * | 2007-12-19 | 2010-09-08 | Nu-Iron Technology, LLC | System and method for producing metallic iron |
EP2225401A4 (en) * | 2007-12-19 | 2010-12-29 | Nu Iron Technology Llc | System and method for producing metallic iron |
US8025711B2 (en) | 2007-12-19 | 2011-09-27 | Nu-Iron Technology, Llc | System and method for producing metallic iron |
US8377371B2 (en) | 2007-12-19 | 2013-02-19 | Nu-Iron Technology, Llc | System and method for producing metallic iron |
AU2008343167B2 (en) * | 2007-12-19 | 2013-07-11 | Nu-Iron Technology, Llc | System and method for producing metallic iron |
EP2725108A1 (en) * | 2007-12-19 | 2014-04-30 | Nu-Iron Technology, Inc | System and method for producing metallic iron |
Also Published As
Publication number | Publication date |
---|---|
AU4525085A (en) | 1986-01-30 |
JPS6144127A (en) | 1986-03-03 |
KR920001610B1 (en) | 1992-02-20 |
ATE34832T1 (en) | 1988-06-15 |
AU574208B2 (en) | 1988-06-30 |
FR2568359A1 (en) | 1986-01-31 |
ZA855378B (en) | 1986-05-28 |
US4745252A (en) | 1988-05-17 |
EP0170585B1 (en) | 1988-06-01 |
BR8503562A (en) | 1986-04-22 |
FR2568359B1 (en) | 1987-01-09 |
ES545584A0 (en) | 1986-06-16 |
KR860000902A (en) | 1986-02-20 |
ES8608665A1 (en) | 1986-06-16 |
DE3563115D1 (en) | 1988-07-07 |
CA1251640A (en) | 1989-03-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0170585B1 (en) | Temperature-homogenizing device for continuously moving metallic products | |
CA2036460C (en) | Glass sheet reheating furnace | |
EP0462011A1 (en) | Induction heating coil | |
FR2934587A1 (en) | UNIT AND METHOD FOR FLAT GLASS SURFACE TREATMENTS WITH GLASS THERMAL CONDITIONING | |
EP0527937B1 (en) | Process and devices for the induction heating of a moving elongate metallurgical product | |
FR2998497B1 (en) | PROCESS FOR SELECTIVE MERGING OF BEDS OF POWDER BY HIGH ENERGY BEAM UNDER A GAS DEPRESSION | |
FR2465692A1 (en) | METHOD AND DEVICE FOR SHAPING GLASS SHEETS USING MOLDS OF DIFFERENT SHAPES | |
US4547256A (en) | Method for thermally treating a semiconductor substrate | |
EP1419675B1 (en) | Cold crucible with induction heating and heat pipe cooling | |
EP0274673A1 (en) | Process for sintering by induction | |
FR2534275A1 (en) | PROCESS FOR PRODUCING ELECTROMAGNETIC STEEL SHEETS OR STRIPS | |
FR2887707A1 (en) | DEVICE AND METHOD FOR GUIDING A METAL STRIP IN CONTINUOUS PROCESS EQUIPMENT | |
EP0013218B1 (en) | Induction heating apparatus for flat metallurgical products | |
EP0044787A1 (en) | Furnace with interchangeable heating walls for the heat treatment of glass sheets | |
FR2658276A3 (en) | Device for localised reheating of metallurgical products moving past | |
FR2628993A3 (en) | Ceramic lateral sealing device - used for sealing mould gap between rollers of a continuous casting mould | |
FR2821774A1 (en) | METHOD FOR HEATING SLABS AND INSTALLATION FOR IMPLEMENTING SAME | |
BE891760A (en) | OVEN FOR HEATING BRAMES, BILLETS AND FLANS | |
WO2019043334A1 (en) | Improved heat treatment device | |
EP0875315A1 (en) | Twin roll continuous caster for metallic strip | |
CA2159164C (en) | Reheating, maintenance and storage furnace for iron and steel products | |
KR101337496B1 (en) | Apparatus For Improving Surface of Cast Strip and Method of it | |
FR2559692A1 (en) | Method for preparing stratified metallic semi-finished products, particularly made from steel, and device for implementing this | |
FR2701493A1 (en) | Plant for pickling a metal strip | |
FR2607582A1 (en) | Induction furnace including a tunnel for the passage of components to be treated |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Designated state(s): AT BE DE FR GB IT LU NL SE |
|
17P | Request for examination filed |
Effective date: 19860725 |
|
17Q | First examination report despatched |
Effective date: 19870604 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE DE FR GB IT LU NL SE |
|
REF | Corresponds to: |
Ref document number: 34832 Country of ref document: AT Date of ref document: 19880615 Kind code of ref document: T |
|
ITF | It: translation for a ep patent filed |
Owner name: ING. DR. LAZZARO MARTINI S.R.L. |
|
REF | Corresponds to: |
Ref document number: 3563115 Country of ref document: DE Date of ref document: 19880707 |
|
GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) | ||
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: FR Payment date: 19930507 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 19930514 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 19930519 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 19930521 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19930526 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 19930616 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: LU Payment date: 19930701 Year of fee payment: 9 |
|
ITTA | It: last paid annual fee | ||
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 19930731 Year of fee payment: 9 |
|
EPTA | Lu: last paid annual fee | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19940717 Ref country code: GB Effective date: 19940717 Ref country code: AT Effective date: 19940717 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19940718 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Effective date: 19940731 |
|
BERE | Be: lapsed |
Owner name: INSTITUT DE RECHERCHES DE LA SIDERURGIE FRANCAISE Effective date: 19940731 |
|
EUG | Se: european patent has lapsed |
Ref document number: 85401464.4 Effective date: 19950210 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Effective date: 19950201 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19940717 |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19950331 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19950401 |
|
EUG | Se: european patent has lapsed |
Ref document number: 85401464.4 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |