EP1259343B1 - Equipment for supplying molten metal to a continuous casting ingot mould and method for using same - Google Patents

Equipment for supplying molten metal to a continuous casting ingot mould and method for using same Download PDF

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Publication number
EP1259343B1
EP1259343B1 EP01903983A EP01903983A EP1259343B1 EP 1259343 B1 EP1259343 B1 EP 1259343B1 EP 01903983 A EP01903983 A EP 01903983A EP 01903983 A EP01903983 A EP 01903983A EP 1259343 B1 EP1259343 B1 EP 1259343B1
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EP
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Prior art keywords
mold
outlets
magnetic field
nozzle
molten metal
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EP01903983A
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German (de)
French (fr)
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EP1259343A1 (en
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Siebo Kunstreich
Marie-Claude Nove
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Rotelec SA
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Rotelec SA
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/122—Accessories for subsequent treating or working cast stock in situ using magnetic fields
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • B22D11/11—Treating the molten metal
    • B22D11/114—Treating the molten metal by using agitating or vibrating means
    • B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
    • B22D41/50—Pouring-nozzles

Definitions

  • the present invention relates to the continuous casting of metals, in particular of steel. It relates more particularly to the arrival of molten metal from above in a continuous casting mold and, more specifically, the techniques using work of the magnetic fields applied on the level of the ingot mold to modify the flows of molten metal when it arrives there.
  • the molten metal is brought into an ingot mold from a distributor placed at a distance above by a conduit plunging, called "submerged nozzle", the outlet openings of which substantially open in the main casting plane parallel to the large faces under the free surface of molten steel in the mold conventionally covered by a liquid sheet of active dairy.
  • the steelmaker Faced with the problem posed by these hydrodynamic disturbances, the steelmaker has today mainly of two axes of response: one using tools available magnetohydrodynamics suitable for the continuous casting of metals; the other focusing on the very geometry of the pouring nozzle.
  • the electromagnetic actuators that we develop for this purpose can influence the flow of recirculation of liquid metal in the ingot mold after it leaves the nozzle for the brake, or accelerate them, or to make them symmetrical on both sides of the submerged nozzle.
  • electromagnetic brakes were initially developed consisting, in apply a field to a determined height level of the interior space of the mold magnetic through which will create braking forces within the moving metal when it passes through this region (Laplace's forces).
  • a magnetic pole designed as an electromagnet with a salient pole wound, having the form of either a localized stud on either side of the nozzle between it and the small end faces of the mold (EP-A-0040383), either of a horizontal bar extending over the entire width of the large face (WO 92/12814) or two parallel bars spaced along the height in order to frame the outlet openings of the nozzle (WO 96/26029, WO 98/53936).
  • the goal is the same: on the one hand, create with the matched pole of opposite sign arranged opposite on the other side of the mold a through magnetic field whose effect is to slow down the too energetic flow flows which go up towards the free surface, and, on the other hand, to better distribute throughout the section of the mold the main flow of liquid metal going down.
  • liquid metal feed jets of the ingot mold having the ability to be able to dose locally the effect of the electromagnetic action by simple adjustment of the parameters of operation of inductors, such as the intensity of the electric current primary supply, or the pulse frequency, so the sliding speed of the magnetic field.
  • such a sliding magnetic field is generally produced by an inductor having several independent phase windings, of type "polyphase linear motor stator" (generally two or three phase) and which is placed opposite a large face of the mold so parallel to the main plane of casting (FR-A-2.324.395; FR-A-2.324.397).
  • phase windings are connected to a different phase of a polyphase power supply, according to a connection order adequate ensuring the desired slip of the magnetic field along the active face from the inductor in a direction orthogonal to the conductors.
  • the other axis of solutions consists in optimizing the geometry of the submerged part pouring nozzles, in particular outlet openings for molten metal.
  • the goal is always the same: check the distribution of liquid metal flows arriving in the mold.
  • nozzles of the type "caisson" US-A- 464.698, JP-A- 63.76753
  • the submerged part of which has a shape general bulbous like that of a painter's brush or a watering can flattened, from which it is supposed to take over the function.
  • nozzles are in fact fairly wide open at the bottom to favor a loudness in the main plane of casting of the casting jets at low speed but on a large passage section.
  • Their main property is to tend to deliver the metal liquid in an ingot mold in a uniform flow, approaching the ideal flow, said "piston", in which the speed gradient between any two points in a section right would be close to zero and said section would quickly become as close as possible from that of the mold.
  • These box-shaped nozzles are beginning to be widespread industrially, especially on continuous casting installations for thin slabs.
  • the metal recirculation flows towards the free surface of the cast metal can indeed be very attenuated, so much so that we could provide, if necessary, additional openings on the top of the box or on the side to allow emission of molten metal threads directed upwards to ensure thermal input of regular support to the free surface, which we know to be necessary for the smooth running of the casting.
  • This category of solutions also includes straight nozzles with two differentiated pairs of lateral outlets which are oriented according to the main plane of casting, parallel to the large faces of the mold.
  • Gills placed in position bass on the barrel barrel generally deliver down the main metal flow to extract from the mold.
  • the other gills are arranged in the upper part in order to deliver a secondary flow intended to thermally supply the free surface, via a regular supply but at low flow rate of "new" molten metal barely reaching the ingot mold, therefore at high enthalpy.
  • the relatively low cost of this type of nozzle can be a significant economic advantage for such wear elements which must be renewed regularly.
  • the electromagnetic actuators are by more flexible in use, therefore better suited to follow such variations. In return, they are not optimized for any particular operating mode. They control the flow of liquid metal once it reaches the mold and sometimes act as an accelerator, sometimes as a flow brake. But, they don't unlike some of the tips seen above, there is absolutely no concern distribution of the incoming flow rate of molten metal between the upper region of the mold (in direction of the free surface) and the bottom (direction of extraction of the cast product). In moreover, they are relatively expensive in investment cost and in consumption cost. of electrical energy, and involve complex and financially heavy modifications of the ingot mold technology that receives them.
  • the object of the present invention is precisely to provide steelmakers with a means for supplying molten metal to a continuous casting ingot mold which allows easily a quick and precise adjustment of the incoming distribution of the metal flow between the upper and lower regions of the mold.
  • said inducing unit is a unit electromagnetic consisting of at least one electromagnet.
  • said inducing unit is constituted by inductors with multi-winding phase of the "sliding field" type facing either side of said main casting plane, and by a supply associated electric supplying each of said windings with direct current separately, and the means for adjusting the relative intensity of the magnetic field include means for moving the location of the magnetic poles in the air gap of said electromagnetic unit.
  • the pole magnetic field must always deliver a directed magnetic field perpendicular to the wall of the mold opposite which the inductor is mounted. Otherwise, the desired effect is not obtained.
  • the opposite magnetic poles have opposite signs in order to create a magnetic field crossing, that is to say whose lines of force connect the two poles by extending perpendicular to the main casting plane in which the jets of metal through the outlet openings of the nozzle placed in the air gap of the two inducers.
  • a magnetic pole of an inductor as the region of the active face of the inductor where the magnetic field it produces is maximum.
  • the pole is the often protruding end of the metallic mass ferromagnetic coil which characterizes the device.
  • the magnetic pole has no fixed material representation attached to a given ferromagnetic mass of the cylinder head, but can move on the active face of the inductor according to the instantaneous intensity phase alternating currents which supply the conductors and their phase shift.
  • a magnetic field "covers" the gills of nozzles, when these are in a region of the interior of the mold where the maximum prevails magnetic induction produced by this field.
  • the first operating variant cited may be preferred if, compared to the size and distance from the magnetic pole used, the gills of the two categories are distant enough from each other on the body of the nozzle so that the values of the magnetic induction in their respective places can be very different whereas the intensity of the field is maximum for example on the gills covered by this field.
  • the second variant cited is better suited to the case, probably the most inevitably frequent, where all the gills are covered and where only the displacement of the pole can provide sufficient field differential between them to obtain marked the results sought by the invention.
  • the displacement of the magnetic pole will be obtained by a mobile mounting of the electromagnet on a chassis secured to the casting machine provided with means which allow it to be moved on the face of the ingot mold on which it is mounted and immobilize it on the chosen location.
  • the loudspeakers will be covered by the magnetic field main, namely those with the highest output rate of molten metal, (generally those directed downwards), because the variations of the action of this field on outlet flows will be more sensitive than those where the metal flow is weaker.
  • the field magnetic covers downward main outlet openings.
  • the invention uses a traversing magnetic field, displaceable in height at the level of the nozzle, but produced by a fixed inductor unit: a pair of inductors opposite one on the other, each of the type “linear motor stator with sliding magnetic field", paired to be in phase opposition and thus each produce a magnetic field whose lines of force are oriented in the same direction (condition specific to obtaining of a magnetic field called "traversing"), but whose phase windings are connected to individual DC power supplies, independently adjustable each other.
  • a traversing magnetic field displaceable in height at the level of the nozzle, but produced by a fixed inductor unit: a pair of inductors opposite one on the other, each of the type “linear motor stator with sliding magnetic field", paired to be in phase opposition and thus each produce a magnetic field whose lines of force are oriented in the same direction (condition specific to obtaining of a magnetic field called "traversing"), but whose phase windings are connected to individual DC power supplies, independently adjustable each other.
  • This change of position of the poles is obtained by selectively activating the windings of the inductor by simply adjusting the operating parameters of the elementary power supplies, namely, in practice, the intensity of the electric currents they deliver.
  • These settings are achievable instantly, during casting itself if desired, away from the machine completely safe for the operators and completely transparent, that is to say without risk of disruption, even minimal, of the smooth running of the operation of casting.
  • the structure of this type of inductor has been known for a long time, and we also know its use in continuous casting of slabs as a means setting the molten metal in motion according to the height of the mold (see par example the aforementioned patents FR-A-2,324,395; FR-A-2324397).
  • the subject of the invention is also a method of implementing the preferred equipment defined above, which consists of adjusting the intensity of the field magnetic, either by moving the position of the poles of the inductor unit, or by modifying the intensity of the electric current supplying the inductor unit.
  • main casting plane means the vertical median plane P passing through the casting axis S in the center of the mold and parallel to the large faces 22 of it.
  • Figures 1 and 5 are precisely in the casting plane principal P.
  • the other analogous plane, but parallel to the small lateral faces 13 of the ingot mold, is he called secondary casting plan.
  • Figures 3a and 3b are in the secondary flow plan.
  • an inductor unit constituted by a pair of inductors electromagnetic 14, 15, is arranged opposite the end portion of the nozzle.
  • These two inductors are paired so as to each produce a magnetic pole making facing each other, of opposite sign in order to create a crossing magnetic field, perpendicular to the large faces 22.
  • this field through is located in "M” in the lower part of the air gap in order to "cover” the gills of category 7 located at the lower end of the body of the nozzle 6.
  • these inductors are designed so that their magnetic poles can be moved together in the air gap.
  • the displacement will be done according to the height of the mold, since the conductors 16 ... 17 'are arranged horizontally.
  • This joint displacement poles of the inductor over a distance of about 10 or 15 cm approximately, will cause a corresponding displacement of the magnetic field passing through the air gap, therefore a correlative modification of the local magnetic conditions at the level of the outlets differentiated 7 and 8 of the nozzle.
  • the consequence is a sought-after redistribution of metal flows leaving its two categories of gills, the total flow remaining unchanged or almost unchanged.
  • an initial position has been represented at M low magnetic field in the air gap, and in N, a high end position after a vertical displacement operation over a distance "d" towards the openings 8 delivering metal jets up.
  • the displacement of the magnetic field can be obtained by means of a couple "electromagnet” type inductors, therefore with a protruding magnetic pole serving as support for a wired conductor wound around, and mounted movable in translation on a chassis secured to the casting installation.
  • This realization therefore requires a physical displacement of the inducing unit.
  • inductor unit as shown schematically in Figure 2, constituted, opposite one on the other on both sides of the large faces 22 of the mold, by a two inductors with multi-winding phases of the "sliding magnetic field” type.
  • the inductor shown here is a flat inductor of the "linear motor stator” type and two-phase (therefore with two phase windings). Its conductors are straight bars of copper 16, 17, 16 ', 17', four in number, mutually parallel, spaced and arranged horizontally.
  • Each winding is composed of two bars connected between it in series-opposition so that the electric current flows through them in directions opposed.
  • the connected bars can be immediately bars neighboring, such as 17 with 16 'and 16 with 17' (inductor with adjacent poles), or offset, such as 16 with 16 'and 17 with 17' (inductor with distributed poles), as shown in the Fig.
  • each phase winding is connected to an elementary current power supply continuous (or straightened) and alone and which is independent of that of the other winding.
  • elementary power supplies symbolized in 18 and 19 in FIG. 2, may have their neutral pooled for convenience. They are integrated in an electrical power supply unit 20 provided with means 2 la and 21b of autonomous adjustment of the intensities of the currents delivered by each power supply elementary 18, 19 in order to be able, for example, to pass a current of intensity maximum in one winding while the other is inactive (zero intensity), and conversely, as well as all the intermediate settings.
  • the field inductor 14 (15) will no longer be able to create a sliding field as it does ordinarily, but a static magnetic field, including the magnetic pole which can be moved on the active face of the inductor in a direction orthogonal to the conductors, simply by suitably modifying the intensities of current in the two windings.
  • a static magnetic field including the magnetic pole which can be moved on the active face of the inductor in a direction orthogonal to the conductors, simply by suitably modifying the intensities of current in the two windings.
  • the low position "M" of the magnetic pole corresponds to a current maximum in the winding 16.16 ', associated with a zero current in the winding 17.17'.
  • the high position "N" in FIG. 3 corresponds to a maximum current in the winding 17,17 'associated with a zero current in the winding 16,16'.
  • the two paired plane inductors 14 and 15 are configured so that their respective magnetic poles facing each other have opposite polarities. In this way, the magnetic field of one adds to the magnetic field of the other at any point in the air gap between the two inductors.
  • the configuration is of the "through field" type: as illustrated by the arrow marks B, the lines of force join the magnetic poles from one inductor to another while crossing perpendicularly to the main casting plane P, therefore the direction of the metal jets in fusion coming out of the nozzle.
  • the nozzle must have outlet openings in the main casting plane of the ingot mold so that the invention can be applied, it can also be provided with other gills placed elsewhere, for example diagonally in direction of the angles of the mold.
  • the more direction the exit jets are orthogonal to the lines of force of the field the more the invention produces its effects, since the efficiency of the electromagnetic action obtained is directly proportional to the vector product between the magnetic field and the velocity vector of the jets as they exit the nozzle openings.
  • the invention gives better results in the case of the nozzles type "box" seen above, it also accommodates straight nozzles, the main thing is that the submerged nozzles used for casting have outlet openings differentiated into at least two categories by directions - the most 5 often upwards and downwards - which they imprint on the jets of molten metal which come out parallel to the large faces.
  • the invention applies by example also for straight nozzles with differentiated side vents up-down on the barrel of the nozzle.
  • the intensity B of the field magnetic remains constant. However, as already indicated, it can very well vary, in modifying the intensity of the supply currents, the field being able to be moved in same time in the air gap, or separately.
  • the inductor 14 (likewise of course inductor 15) can be split into two identical parts 14a and 14b placed side by side side on the same face of the ingot mold on either side of the casting axis S on which is moreover, conventionally centered the pouring nozzle.
  • autonomous adjustments of the inductive parts 14a and 14b we thus arrive at to better symmetrize the flows in the ingot mold because we intervene on them at the moment they get out of the nozzle.
  • each part inductive is supplied with current by its own elementary power supply (not shown) so that different height adjustments can be made if necessary of the magnetic pole on each of them, as well as separate modifications of the intensities of current flowing through them.
  • inductors of the "sliding field” type we can opt not only for electromagnets, as already mentioned, but also for permanent, natural or industrial magnets.
  • the expression "elementary direct current power supplies" used in the presentation means, not necessarily an addition of unit feeds structurally independent, but still a single polyphase supply, two or three phases, and adjustable frequency, which is set at zero frequency to obtain a direct current.
  • Polyphase power supplies of this type are well known. They are of the inverter type with adjustable chopping threshold and are commonly used to activate electric motors with rotating or sliding magnetic field. Setting as a function of such a power supply to supply the windings of inductor 14, at the rate of one phase per winding, consists in adjusting the inverter to the zero frequency, making such adjustments at selected times so that the intensities of the currents in each phase are, at these times, those which one wishes to obtain in the windings connected to these phases.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
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Abstract

The apparatus comprises a submerged entry nozzle (6) having outlets in the main casting plane (P) which differ in their direction of output and fall within two categories (7, 8), said nozzle being associated with two inductors (14, 15) opposite each other on each broad face (22) of the casting mold forming a gap which surrounds the nozzle and producing a traversing magnetic field covering the outlets of at least one category (7), means being provided for adjusting the intensity of the field or for moving it so as to be able to change the distribution between the outlets of the total flow of molten metal. In particular, implementing the invention makes it possible to adjust at any time that fraction of the metal flow which is directed toward the free surface (9) with respect to that, main, fraction directed toward the bottom of the mold. Advantageously, the invention applies to the continuous casting of steel slabs.

Description

La présente invention a trait à la coulée continue des métaux, notamment de l'acier. Elle concerne plus particulièrement l'arrivée du métal en fusion par le haut dans une lingotière de coulée continue et, plus précisément encore, les techniques mettant en oeuvre des champs magnétiques appliqués au niveau de la lingotière pour modifier les écoulements du métal en fusion lors de son arrivée dans celle ci.The present invention relates to the continuous casting of metals, in particular of steel. It relates more particularly to the arrival of molten metal from above in a continuous casting mold and, more specifically, the techniques using work of the magnetic fields applied on the level of the ingot mold to modify the flows of molten metal when it arrives there.

On sait que l'application d'un champ magnétique à une lingotière de coulée continue, lorsque l'action électromagnétique est conduite de manière appropriée, permet d'augmenter la productivité de l'installation de coulée tout en préservant la qualité métallurgique des produits coulés obtenus, voire même en l'améliorant. On a pu en effet déjà mettre en lumière la nuisance à cet égard des turbulences hydrodynamiques dues aux écoulements recirculants qui s'établissent de plus en plus vigoureusement au sein de la lingotière lorsqu'on augmente la vitesse de coulée, et ce notamment dans le cas de la coulée de produits à section allongée, tels que des brames par exemple.We know that the application of a magnetic field to a casting mold continuous, when the electromagnetic action is properly conducted, allows increase the productivity of the casting installation while preserving the quality metallurgy of the cast products obtained, or even improving it. We could indeed already highlight the nuisance in this regard of hydrodynamic turbulence due to recirculating flows which are established more and more vigorously within the ingot mold when increasing the casting speed, especially in the case of casting of elongated section products, such as slabs for example.

On rappelle que, lors de la coulée continue de brames, le métal en fusion est apporté en lingotière depuis un répartiteur placé à distance au-dessus par un conduit plongeant, appelé "busette immergée", dont les ouïes de sortie débouchent sensiblement dans le plan principal de coulée parallèlement aux grandes faces sous la surface libre de l'acier en fusion dans la lingotière classiquement recouverte par une nappe liquide de laitier actif.It is recalled that, during the continuous casting of slabs, the molten metal is brought into an ingot mold from a distributor placed at a distance above by a conduit plunging, called "submerged nozzle", the outlet openings of which substantially open in the main casting plane parallel to the large faces under the free surface of molten steel in the mold conventionally covered by a liquid sheet of active dairy.

On a pu établir que la vitesse des jets de métal liquide à la sortie des ouïes de la busette s'élève à plusieurs mètres par seconde dès que la vitesse de coulée atteint 1 à 1,5m/mn environ. Les écoulements recirculants qui en résultent alors dans la lingotière agitent fortement l'interface métal-laitier. Ces fluctuations de la surface libre du métal coulé sont responsables d'irrégularités de solidification de la première peau du produit coulé que l'on sait être à l'origine de défauts gênants, voire rédhibitoires sur le produit final (boursouflures, exfoliations, etc...). De plus, des fragments de laitier de couverture peuvent être entraínés en lingotière dans le coeur même du produit coulé, dégradant ainsi la propreté du métal solidifié obtenu.It has been established that the velocity of the jets of liquid metal leaving the gills of the nozzle rises to several meters per second as soon as the casting speed reaches 1 to 1.5m / min approximately. The recirculating flows which then result in the ingot mold strongly agitate the metal-slag interface. These fluctuations in the free surface of the metal poured are responsible for irregularities in the solidification of the first skin of the product cast which is known to be the cause of annoying or even unacceptable mistakes in the product final (blisters, exfoliations, etc ...). In addition, fragments of roofing slag can be dragged into the mold in the very heart of the cast product, thus degrading the cleanliness of the solidified metal obtained.

Face au problème posé par ces perturbations hydrodynamiques, l'aciériste dispose aujourd'hui principalement de deux axes de réponse: l'un faisant appel aux outils disponibles de la magnétohydrodynamique adaptés à la coulée continue des métaux; l'autre s'attachant à la géométrie même de la busette de coulée.Faced with the problem posed by these hydrodynamic disturbances, the steelmaker has today mainly of two axes of response: one using tools available magnetohydrodynamics suitable for the continuous casting of metals; the other focusing on the very geometry of the pouring nozzle.

Les actionneurs électromagnétiques que l'on développe à cet effet, qu'ils soient à champ magnétique statique ou glissant, permettent d'influencer les écoulements de recirculation de métal liquide dans la lingotière après sa sortie de la busette pour les freiner, ou les accélérer, ou pour les symétriser de part et d'autre de la busette immergée. The electromagnetic actuators that we develop for this purpose, whether they are static or sliding magnetic field, can influence the flow of recirculation of liquid metal in the ingot mold after it leaves the nozzle for the brake, or accelerate them, or to make them symmetrical on both sides of the submerged nozzle.

Ainsi, des freins électromagnétiques ont initialement été développés consistant, à appliquer à un niveau en hauteur déterminé de l'espace intérieur de la lingotière un champ magnétique traversant qui va créer au sein du métal en mouvement des forces de freinage lorsque celui-ci passe dans cette région (les forces de Laplace). A cet effet, il a été proposé de disposer sur chaque grande face de la lingotière un pôle magnétique, conçu comme un électroaimant à pôle saillant bobiné, présentant la forme soit d'un plot localisé de part et d'autre de la busette entre celle-ci et les petites faces d'extrémité de la lingotière (EP-A-0040383), soit d'une barre horizontale s'étendant sur toute la largeur de la grande face (WO 92/12814) ou de deux barres parallèles espacées sur la hauteur afin d'encadrer les ouïes de sortie de la busette (WO 96/26029, WO 98/53936). Quelque soit la géométrie retenue, le but est le même: d'une part, créer avec le pôle apparié de signe opposé disposé en regard sur l'autre face de la lingotière un champ magnétique traversant dont l'effet est de freiner les flux d'écoulement trop énergiques qui remontent vers la surface libre, et, d'autre part, de mieux répartir dans toute la section de la lingotière le flux principal de métal liquide qui descend vers le bas.Thus, electromagnetic brakes were initially developed consisting, in apply a field to a determined height level of the interior space of the mold magnetic through which will create braking forces within the moving metal when it passes through this region (Laplace's forces). To this end, it has been proposed to have on each large face of the mold a magnetic pole, designed as an electromagnet with a salient pole wound, having the form of either a localized stud on either side of the nozzle between it and the small end faces of the mold (EP-A-0040383), either of a horizontal bar extending over the entire width of the large face (WO 92/12814) or two parallel bars spaced along the height in order to frame the outlet openings of the nozzle (WO 96/26029, WO 98/53936). Whatever the geometry retained, the goal is the same: on the one hand, create with the matched pole of opposite sign arranged opposite on the other side of the mold a through magnetic field whose effect is to slow down the too energetic flow flows which go up towards the free surface, and, on the other hand, to better distribute throughout the section of the mold the main flow of liquid metal going down.

Pour conférer à ce type de technique une plus grande souplesse de réglage, il a été proposé d'utiliser des champs magnétiques, non plus statiques, mais glissants, lesquels, on le sait, ont la faculté d'entraíner le métal liquide dans leur déplacement (EP-A- 0151 648, WO 83/02079, JP-B-1 534 702). Deux inducteurs à champ glissant horizontalement (conducteurs orientés verticalement) sont placés sur chaque grande face de la lingotière de part et d'autre d'une busette immergée à ouïes de sortie latérales, entre celle-ci et les petites faces d'extrémités de manière à faire intercepter par le champ magnétique glissant le métal en fusion dès son arrivée dans ces zones de la lingotière. On parvient ainsi à accélérer (ou à freiner, selon le sens de déplacement relatif donné au champ glissant) les jets d'alimentation en métal liquide de la lingotière en ayant la faculté de pouvoir doser localement l'effet de l'action électromagnétique par simple réglage des paramètres de fonctionnement des inducteurs, comme par exemple l'intensité du courant électrique d'alimentation primaire, ou la fréquence de pulsation, donc la vitesse de glissement du champ magnétique.To give this type of technique greater flexibility of adjustment, it has been proposed to use magnetic fields, no longer static, but sliding, which, we know it, have the faculty to entrain the liquid metal in their displacement (EP-A- 0151 648, WO 83/02079, JP-B-1 534 702). Two horizontally sliding field inductors (vertically oriented conductors) are placed on each large face of the mold on either side of a submerged nozzle with lateral outlet openings, between this and the small end faces so as to be intercepted by the sliding magnetic field the molten metal upon arrival in these areas of the mold. We thus arrive at accelerate (or brake, depending on the relative direction of movement given to the sliding field) liquid metal feed jets of the ingot mold having the ability to be able to dose locally the effect of the electromagnetic action by simple adjustment of the parameters of operation of inductors, such as the intensity of the electric current primary supply, or the pulse frequency, so the sliding speed of the magnetic field.

On rappelle au besoin qu'un tel champ magnétique glissant est généralement produit par un inducteur ayant plusieurs enroulements de phase indépendants, de type "stator de moteur linéaire polyphasé" (bi-ou triphasé généralement) et que l'on place en regard d'une grande face de la lingotière donc parallèlement au plan principal de coulée (FR-A-2.324.395; FR-A-2.324.397). Chaque enroulement est connecté à une phase différente d'une alimentation électrique polyphasée, selon un ordre de branchement adéquat assurant le glissement recherché du champ magnétique le long de la face active de l'inducteur dans une direction orthogonale aux conducteurs.If necessary, it is recalled that such a sliding magnetic field is generally produced by an inductor having several independent phase windings, of type "polyphase linear motor stator" (generally two or three phase) and which is placed opposite a large face of the mold so parallel to the main plane of casting (FR-A-2.324.395; FR-A-2.324.397). Each winding is connected to a different phase of a polyphase power supply, according to a connection order adequate ensuring the desired slip of the magnetic field along the active face from the inductor in a direction orthogonal to the conductors.

Il a également déjà été proposé, dans le but cette fois de contrecarrer des phénomènes observés de propagation de vagues sur la surface libre d'une petite face à l'autre de la lingotière, de symétriser au mieux les écoulements de métal en fusion arrivant en lingotière dans les zones de part et d'autre de la busette à l'aide d'un plot magnétique mobile, mécaniquement réglable en position, ou de deux plots magnétiques fixes adjacents intercorrélés dans leurs actions respectives sur le métal en mouvement (EP-A-0.832.704; JP-A-03275256).It has also already been proposed, this time with the aim of thwarting observed phenomena of wave propagation on the free surface of a small face the other of the ingot mold, to best symmetrical the flows of molten metal arriving in an ingot mold in the areas on either side of the nozzle using a magnetic pad mobile, mechanically adjustable in position, or two fixed magnetic studs adjacent intercorrelated in their respective actions on the moving metal (EP-A-0.832.704; JP-A-03275256).

L'autre axe de solutions consiste à optimiser la géométrie de la partie immergée des busettes de coulée, notamment des ouïes de sortie du métal en fusion. Le but est toujours le même: contrôler la répartition des écoulements de métal liquide parvenant dans la lingotière.The other axis of solutions consists in optimizing the geometry of the submerged part pouring nozzles, in particular outlet openings for molten metal. The goal is always the same: check the distribution of liquid metal flows arriving in the mold.

On trouve par exemple dans cette catégorie de solutions des busettes de type "caisson" (US-A- 464.698, JP-A- 63.76753), dont la partie immergée présente une forme générale bulbeuse rappelant celle d'un pinceau de peintre ou d'une pomme d'arrosoir aplatie, dont elle est d'ailleurs supposée reprendre la fonction.In this category of solutions, for example, there are nozzles of the type "caisson" (US-A- 464.698, JP-A- 63.76753), the submerged part of which has a shape general bulbous like that of a painter's brush or a watering can flattened, from which it is supposed to take over the function.

Ces busettes sont en effet assez largement ouvertes vers le bas pour favoriser une sonie dans le plan principal de coulée des jets de coulée à faible vitesse mais sur une grande section de passage. Leur propriété principale est de tendre ainsi à délivrer le métal liquide en lingotière selon un écoulement uniforme, approchant l'écoulement idéal, dit "piston", dans lequel le gradient de vitesse entre deux points quelconques d'une section droite serait voisin de zéro et ladite section deviendrait rapidement la plus proche possible de celle de la lingotière. Ces busettes en forme de caisson commencent à être répandues industriellement, notamment sur les installations de coulée continue de brames minces. Les flux de recirculation de métal en direction de la surface libre du métal coulé peuvent être en effet très atténués, à tel point d'ailleurs que l'on pourrait prévoir le cas échéant des ouvertures supplémentaires sur le haut du caisson ou sur le côté pour permettre l'émission de filets de métal en fusion dirigés vers le haut pour assurer un apport thermique d'appoint régulier à la surface libre, que l'on sait être nécessaire au bon déroulement de la coulée.These nozzles are in fact fairly wide open at the bottom to favor a loudness in the main plane of casting of the casting jets at low speed but on a large passage section. Their main property is to tend to deliver the metal liquid in an ingot mold in a uniform flow, approaching the ideal flow, said "piston", in which the speed gradient between any two points in a section right would be close to zero and said section would quickly become as close as possible from that of the mold. These box-shaped nozzles are beginning to be widespread industrially, especially on continuous casting installations for thin slabs. The metal recirculation flows towards the free surface of the cast metal can indeed be very attenuated, so much so that we could provide, if necessary, additional openings on the top of the box or on the side to allow emission of molten metal threads directed upwards to ensure thermal input of regular support to the free surface, which we know to be necessary for the smooth running of the casting.

On trouve également dans cette catégorie de solutions des busettes droites à deux paires différenciées d'ouïes de sortie latérale que l'on oriente selon le plan principal de coulée, parallèlement aux grandes faces de la lingotière. Des ouïes placées en position basse sur le fut de la busette délivrent globalement vers le bas le flux de métal principal à extraire de la lingotière. Les autres ouïes sont disposées en partie haute afin de délivrer un flux secondaire destiné à alimenter thermiquement la surface libre, via un apport régulier mais à faible débit de métal en fusion "neuf' à peine parvenu en lingotière, donc à forte enthalpie. Le relativement faible coût de revient de ce type de busette peut être un avantage économique significatif pour des éléments d'usure de ce genre qui doivent être renouvelés régulièrement.This category of solutions also includes straight nozzles with two differentiated pairs of lateral outlets which are oriented according to the main plane of casting, parallel to the large faces of the mold. Gills placed in position bass on the barrel barrel generally deliver down the main metal flow to extract from the mold. The other gills are arranged in the upper part in order to deliver a secondary flow intended to thermally supply the free surface, via a regular supply but at low flow rate of "new" molten metal barely reaching the ingot mold, therefore at high enthalpy. The relatively low cost of this type of nozzle can be a significant economic advantage for such wear elements which must be renewed regularly.

Cela dit, quelque soit la conformation retenue pour la busette, droite ou caissonnée, celle-ci est nécessairement figée dans sa géométrie et ne peut donc être optimisée que pour un seul mode de fonctionnement de l'opération de coulée, ou pour un format coulé particulier. Ce type de solutions apparaít donc mal adapté aux inévitables variations ou modifications de fonctionnement subis ou voulus propres aux machines de coulée continue modernes, tels que variations de la vitesse de coulée, changements de formats, etc...That said, whatever the conformation chosen for the nozzle, straight or boxed, it is necessarily fixed in its geometry and therefore cannot be optimized for only one operating mode of the casting operation, or for one particular cast format. This type of solution therefore appears ill-suited to the inevitable variations or modifications of operation undergone or intended specific to the machines of modern continuous casting, such as variations in casting speed, changes in formats, etc ...

Les actionneurs électromagnétiques (freins, accélérateurs, symétriseurs) sont par nature plus souples d'utilisation, donc mieux appropriés pour suivre de telles variations. En contrepartie, ils ne sont optimisés pour aucun mode de fonctionnement particulier. Ils contrôlent les écoulements du métal liquide une fois celui-ci parvenu en lingotière et agissent alors tantôt en accélérateur, tantôt en frein d'écoulements. Mais, ils ne se préoccupent absolument pas, contrairement à certaines busettes vu précédemment, de la répartition du débit d'arrivée de métal en fusion entre la région haute de la lingotière (en direction de la surface libre) et le bas (direction de l'extraction du produit coulé). En outre, ils sont relativement chers en coût d'investissement et en coût de consommation d'énergie électrique, et impliquent des modifications complexes et financièrement lourdes de la technologie des lingotière qui les reçoivent.The electromagnetic actuators (brakes, accelerators, baluns) are by more flexible in use, therefore better suited to follow such variations. In return, they are not optimized for any particular operating mode. They control the flow of liquid metal once it reaches the mold and sometimes act as an accelerator, sometimes as a flow brake. But, they don't unlike some of the tips seen above, there is absolutely no concern distribution of the incoming flow rate of molten metal between the upper region of the mold (in direction of the free surface) and the bottom (direction of extraction of the cast product). In moreover, they are relatively expensive in investment cost and in consumption cost. of electrical energy, and involve complex and financially heavy modifications of the ingot mold technology that receives them.

Le but de la présente invention est précisément de procurer aux aciéristes un moyen d'alimentation en métal en fusion d'une lingotière de coulée continue qui permette aisément un réglage rapide et précis de la répartition entrante du débit de métal entre les régions haute et basse de la lingotière.The object of the present invention is precisely to provide steelmakers with a means for supplying molten metal to a continuous casting ingot mold which allows easily a quick and precise adjustment of the incoming distribution of the metal flow between the upper and lower regions of the mold.

Avec cet objectif en vue, l'invention a pour objet un équipement pour alimenter en métal en fusion une lingotière d'une installation de coulée continue de produits à section rectangulaire, tel que des brames, comprenant:

  • une busette immergée dotée d'ouïes de sortie du métal en fusion situées dans, ou sensiblement dans, le plan principal de coulée parallèle aux grandes faces de la lingotière, ces ouïes étant différenciées par leur direction de sortie en au moins deux catégories distinctes; et
  • une unité inductrice placée en regard des grandes faces de la lingotière pour y produire des pôles magnétiques de signes opposés se faisant face de part et d'autre dudit plan principal de coulée caractérisé en ce que ladite unité inductrice a son entrefer sensiblement circonscrit à la busette, et délivre un champ magnétique traversant couvrant les ouïes d'au moins une desdites catégories distinctes ; et en ce que lédit équipement comprend
  • des moyens de réglage de l'intensité relative dudit champ magnétique à l'endroit des ouïes de sortie de ladite catégorie couverte par rapport aux ouïes de l'autre catégorie, de manière à pouvoir modifier la répartition du débit total de métal en fusion entre toutes les ouïes de sortie de ladite busette.
    • With this objective in view, the subject of the invention is equipment for supplying molten metal to an ingot mold for a continuous casting installation for products with rectangular section, such as slabs, comprising:
  • a submerged nozzle provided with outlet openings for molten metal located in, or substantially in, the main casting plane parallel to the large faces of the ingot mold, these openings being differentiated by their outlet direction into at least two distinct categories; and
  • an induction unit placed opposite the large faces of the ingot mold to produce there magnetic poles of opposite signs facing each other on said main casting plane characterized in that said induction unit has its air gap substantially circumscribed to the nozzle , and delivers a through magnetic field covering the gills of at least one of said distinct categories; and in that the said equipment includes
  • means for adjusting the relative intensity of said magnetic field at the outlet openings of said covered category relative to the openings of the other category, so as to be able to modify the distribution of the total flow of molten metal between all the outlet openings of said nozzle.

    • Conformément à une variante de réalisation, ladite unité inductrice est une unité électromagnétique constituée par au moins un électroaimant. According to an alternative embodiment, said inducing unit is a unit electromagnetic consisting of at least one electromagnet.

    Conformément à une autre variante de réalisation, ladite unité inductrice est constituée par des inducteurs à pluri-enroulements de phase de type "à champ glissant" se faisant face de part et d'autre dudit plan principal de coulée, et par une alimentation électrique associée alimentant en courant continu chacun desdits enroulements séparément, et les moyens de réglage de l'intensité relative du champ magnétique comprennent des moyens pour déplacer la localisation des pôles magnétiques dans l'entrefer de ladite unité électromagnétique.According to another alternative embodiment, said inducing unit is constituted by inductors with multi-winding phase of the "sliding field" type facing either side of said main casting plane, and by a supply associated electric supplying each of said windings with direct current separately, and the means for adjusting the relative intensity of the magnetic field include means for moving the location of the magnetic poles in the air gap of said electromagnetic unit.

    Il est envisageable d'utiliser un inducteur (électroaimant ou un inducteur de type "champ glissant") que sur une seule face de la lingotière, mais au détriment dans ce cas de la puissance électromagnétique disponible. En tout cas, selon l'invention, le pôle magnétique de l'inducteur doit toujours délivrer un champ magnétique dirigé perpendiculairement à la paroi de la lingotière en regard de laquelle l'inducteur est monté. Sinon, l'effet recherché n'est pas obtenu. Ainsi, si deux inducteurs sont face à face, les pôles magnétiques en regard sont de signes opposés afin de créer un champ magnétique traversant, c'est-à-dire dont les lignes de force relient les deux pôles en s'étendant perpendiculairement au plan principal de coulée dans lequel se développent les jets de métal au travers des ouïes de sortie de la busette placée dans l'entrefer des deux inducteurs.It is possible to use an inductor (electromagnet or an inductor of the type "sliding field") only on one side of the mold, but to the detriment in this case of the electromagnetic power available. In any case, according to the invention, the pole magnetic field must always deliver a directed magnetic field perpendicular to the wall of the mold opposite which the inductor is mounted. Otherwise, the desired effect is not obtained. Thus, if two inductors are facing each other, the opposite magnetic poles have opposite signs in order to create a magnetic field crossing, that is to say whose lines of force connect the two poles by extending perpendicular to the main casting plane in which the jets of metal through the outlet openings of the nozzle placed in the air gap of the two inducers.

    On définit un pôle magnétique d'un inducteur comme la région de la face active de l'inducteur où le champ magnétique qu'il produit est maximal. Dans le cas d'un électroaimant, le pôle est l'extrémité, souvent saillante, de la masse métallique ferromagnétique bobinée qui caractérise l'appareil. Dans le cas d'un inducteur de type à champ glissant à pluri-enroulements de phase, le pôle magnétique n'a pas de représentation matérielle fixe attachée à une masse ferromagnétique donnée de la culasse, mais peut se déplacer sur la face active de l'inducteur en fonction de l'intensité instantanée des courants alternatifs de phase qui alimentent les conducteurs et de leur déphasage. On dira de même qu'un champ magnétique "couvre" des ouïes de busettes, lorsque celles-ci se trouvent dans une région de l'espace intérieur de la lingotière où règne le maximum d'induction magnétique produite par ce champ.We define a magnetic pole of an inductor as the region of the active face of the inductor where the magnetic field it produces is maximum. In the case of a electromagnet, the pole is the often protruding end of the metallic mass ferromagnetic coil which characterizes the device. In the case of a type inductor sliding field with multiple phase windings, the magnetic pole has no fixed material representation attached to a given ferromagnetic mass of the cylinder head, but can move on the active face of the inductor according to the instantaneous intensity phase alternating currents which supply the conductors and their phase shift. We will also say that a magnetic field "covers" the gills of nozzles, when these are in a region of the interior of the mold where the maximum prevails magnetic induction produced by this field.

    Ces précisons étant faites, on comprend qu'il est aisé de modifier l'action du champ magnétique dans la zone des ouïes de la busette couverte par ce champ, conformément à l'invention (relativement à l'action éventuellement exercée à l'endroit des autres ouïes) par un réglage adéquat de l'intensité de ce champ dans la zone considérée. Cette action sera menée soit en faisant varier (en diminuant, ou en augmentant) l'intensité du champ magnétique sans modifier la position du pôle magnétique qui le délivre, soit en modifiant la position de celui ci sur les grandes faces de lingotière en conservant son intensité. La première variante opératoire citée pourra être préférée si, par rapport à la taille et à l'éloignement du pôle magnétique utilisé, les ouïes des deux catégories sont assez éloignées les unes des autres sur le corps de la busette pour que les valeurs de l'induction magnétique à leurs endroits respectifs puissent être très différentes alors que l'intensité du champ est maximale par exemple sur les ouïes couvertes par ce champ. En revanche, la seconde variante citée est mieux adaptée au cas, sans doute le plus inévitablement fréquent, où toutes les ouïes sont couvertes et où seul le déplacement du pôle peut procurer un différentiel de champ suffisant entre elles pour obtenir de façon marquée les résultats recherchés par l'invention.These details being made, we understand that it is easy to modify the action of the magnetic field in the area of the gills of the nozzle covered by this field, in accordance with the invention (relative to the action possibly exerted on the other hearing) by an adequate adjustment of the intensity of this field in the area considered. This action will be carried out either by varying (decreasing, or increasing) the intensity of the magnetic field without modifying the position of the magnetic pole which delivers it, modifying the position of this one on the large faces of the ingot mold while keeping its intensity. The first operating variant cited may be preferred if, compared to the size and distance from the magnetic pole used, the gills of the two categories are distant enough from each other on the body of the nozzle so that the values of the magnetic induction in their respective places can be very different whereas the intensity of the field is maximum for example on the gills covered by this field. In however, the second variant cited is better suited to the case, probably the most inevitably frequent, where all the gills are covered and where only the displacement of the pole can provide sufficient field differential between them to obtain marked the results sought by the invention.

    Bien entendu, dans le cas d'un électroaimant, le déplacement du pôle magnétique sera obtenu par un montage mobile de l'électroaimant sur un châssis solidaire de la machine de coulée doté de moyens qui permettent de le déplacer sur la face de la lingotière sur laquelle il est monté et de l'immobiliser sur le lieu choisi.Of course, in the case of an electromagnet, the displacement of the magnetic pole will be obtained by a mobile mounting of the electromagnet on a chassis secured to the casting machine provided with means which allow it to be moved on the face of the ingot mold on which it is mounted and immobilize it on the chosen location.

    On peut également dans certains cas trouver avantage à dédoubler l'inducteur en deux parties inductives placées côte à côte sur la même face de la lingotière, chaque partie contrôlant ainsi les ouïes de sortie disposées d'un coté de la busette, indépendamment de celles disposées de l'autre coté.We can also in some cases find it advantageous to split the inductor into two inductive parts placed side by side on the same face of the mold, each part thus controlling the outlet openings arranged on one side of the nozzle, regardless of those on the other side.

    Quelque soit la variante de réalisation retenue, on aura sans doute déjà compris que l'idée à la base de l'invention consiste à utiliser un champ magnétique en quelque sorte comme un clapet immatériel d'obturation du passage offert par une catégorie d'ouies de la busette pour modifier le débit de sortie de l'autre catégorie d'ouïes. Le débit d'alimentation étant lui constant, ou en tout cas peu affecté par l'action du champ magnétique, celle ci, qui agit directement au niveau d'une catégories d'ouïes de sortie, aura pour effet de modifier la répartition des fractions du débit total entre les deux catégories d'ouïes. On réalise de la sorte une busette immergée à géométrie variable sans modification de sa forme.Whatever variant is chosen, we will no doubt already have understood that the idea behind the invention is to use a magnetic field in some sort of like an intangible shutter for closing the passage offered by a category of hearing of the nozzle to modify the output flow of the other category of hearing. The flow power being constant, or in any case little affected by the action of the field magnetic, this one, which acts directly at the level of a category of output gills, will have the effect of modifying the distribution of the fractions of the total flow between the two hearing categories. This produces a submerged nozzle with variable geometry without modification of its shape.

    De préférence, on couvrira par le champ magnétique les ouïes de sonie principales, à savoir celles dont le débit de sortie du métal en fusion est le plus important, (généralement celles dirigées vers le bas), car les variations de l'action de ce champ sur les écoulements de sortie y seront plus sensibles que sur celles où le débit de métal est plus faible. Dans la suite de l'exposé, on considérera par souci de clarté que le champ magnétique couvre des ouïes de sortie principales dirigées vers le bas.Preferably, the loudspeakers will be covered by the magnetic field main, namely those with the highest output rate of molten metal, (generally those directed downwards), because the variations of the action of this field on outlet flows will be more sensitive than those where the metal flow is weaker. In the rest of the presentation, it will be considered for the sake of clarity that the field magnetic covers downward main outlet openings.

    On aura également compris que dans une forme de réalisation préférée, l'invention fait appel à un champ magnétique traversant, déplaçable en hauteur au niveau de la busette, mais produit par une unité inductrice fixe: un couple d'inducteurs en regard l'un de l'autre, chacun du type "stator de moteur linéaire à champ magnétique glissant", appariés pour être en opposition de phase et produire ainsi chacun un champ magnétique dont les lignes de forces sont orientées dans le même sens (condition propre à l'obtention d'un champ magnétique dit "traversant"), mais dont les enroulements de phase sont connectés à des alimentations individuelles à courant continu, réglables indépendamment les unes des autres. Une telle unité inductrice est alors apte, comme on le sait, à générer des pôles magnétiques de signes opposés, donc un champ magnétique statique traversant, localisables là où on le veut dans l'entrefer. Ce changement de position des pôles s'obtient en activant de manière sélective les enroulements de l'inducteur par simple réglage des paramètres de fonctionnement des alimentations élémentaires, à savoir, en pratique, l'intensité des courants électriques qu'elles délivrent. Ces réglages sont réalisables instantanément, pendant la coulée elle-même si on le souhaite, à distance de la machine de coulée, en toute sécurité pour les opérateurs, et de manière totalement transparente, c'est-à-dire sans risque de perturbation, même minime, du bon déroulement de l'opération de coulée. On rappelle que la structure de ce type d'inducteur est connue de longue date, et on connaít bien aussi son utilisation en coulée continue de brames en tant que moyen de mise en mouvement du métal en fusion selon la hauteur de la lingotière (cf. par exemple les brevets prémentionnés FR-A-2.324.395; FR-A-2.324.397).It will also be understood that in a preferred embodiment, the invention uses a traversing magnetic field, displaceable in height at the level of the nozzle, but produced by a fixed inductor unit: a pair of inductors opposite one on the other, each of the type "linear motor stator with sliding magnetic field", paired to be in phase opposition and thus each produce a magnetic field whose lines of force are oriented in the same direction (condition specific to obtaining of a magnetic field called "traversing"), but whose phase windings are connected to individual DC power supplies, independently adjustable each other. As we know, such an inducing unit is then capable of generating magnetic poles of opposite signs, therefore a traversing static magnetic field, located wherever you want in the air gap. This change of position of the poles is obtained by selectively activating the windings of the inductor by simply adjusting the operating parameters of the elementary power supplies, namely, in practice, the intensity of the electric currents they deliver. These settings are achievable instantly, during casting itself if desired, away from the machine completely safe for the operators and completely transparent, that is to say without risk of disruption, even minimal, of the smooth running of the operation of casting. It is recalled that the structure of this type of inductor has been known for a long time, and we also know its use in continuous casting of slabs as a means setting the molten metal in motion according to the height of the mold (see par example the aforementioned patents FR-A-2,324,395; FR-A-2324397).

    Ainsi, l'invention a également pour objet un procédé de mise en oeuvre de l'équipement préféré défini ci avant, et qui consiste à régler l'intensité du champ magnétique, soit en déplaçant la position des pôles de l'unité inductrice, soit en modifiant l'intensité du courant électrique alimentant l'unité inductrice.Thus, the subject of the invention is also a method of implementing the preferred equipment defined above, which consists of adjusting the intensity of the field magnetic, either by moving the position of the poles of the inductor unit, or by modifying the intensity of the electric current supplying the inductor unit.

    L'invention sera bien comprise, et d'autres aspects et avantages apparaítront plus clairement au vu de la description qui suit, donnée uniquement à titre d'exemple non limitatif de réalisation en référence aux planches de dessins annexées sur lesquelles:

    • la figure 1 représente schématiquement, vue de face en coupe verticale selon le plan principal de coulée, une lingotière de coulée continue de brames d'acier pourvue à sa partie supérieure d'un équipement d'alimentation en métal en fusion conforme à l'invention selon une variante de réalisation à un seul inducteur par face de lingotière;
    • la figure 2, en vignette de la figure 1, est un schéma explicitant la structure d'un inducteur-plan de type connu pouvant convenir pour la mise en oeuvre de l'invention, et relié à cet effet à une alimentation électrique à courant continu;
    • la figure 3 est un schéma issu d'une vue en section verticale selon le plan vertical R-R de la figure 1 et illustrant, vu par le côté de la lingotière, le mode de fonctionnement "à champ traversant " de l'invention.
    • la figure 4 est un schéma issu d'une vue en section horizontale selon le plan horizontal Q-Q de la figure 1 et illustrant, vu selon selon l'axe de coulée, le mode de fonctionnement "à champ traversant "de l'invention;
    • la figure 5 est une vue schématique analogue à celle de la figure 1, mais illustrant une variante de réalisation de l'invention à deux inducteurs côte à côte par face de la lingotière.
    The invention will be well understood, and other aspects and advantages will appear more clearly in the light of the description which follows, given solely by way of nonlimiting example of embodiment with reference to the plates of attached drawings in which:
    • Figure 1 shows schematically, front view in vertical section along the main casting plane, a mold for continuous casting of steel slabs provided at its upper part with a molten metal supply equipment according to the invention according to an alternative embodiment with a single inductor per face of the mold;
    • Figure 2, in thumbnail of Figure 1, is a diagram explaining the structure of a plane inductor of known type which may be suitable for the implementation of the invention, and connected for this purpose to a DC power supply ;
    • Figure 3 is a diagram from a vertical section view along the vertical plane RR of Figure 1 and illustrating, seen from the side of the mold, the operating mode "through field" of the invention.
    • Figure 4 is a diagram from a horizontal section view along the horizontal plane QQ of Figure 1 and illustrating, seen along the casting axis, the operating mode "through field" of the invention;
    • Figure 5 is a schematic view similar to that of Figure 1, but illustrating an alternative embodiment of the invention with two inductors side by side by face of the mold.

    Sur ces figures, les mêmes éléments sont désignés par des références identiques.In these figures, the same elements are designated by identical references.

    Une lingotière 1, en cuivre ou en alliage de cuivre énergiquement refroidi par une circulation d'eau sur sa paroi extérieure, reçoit par le haut un certain débit de métal en fusion 2 qu'elle évacue vers le bas sous la forme d'un demi-produit sidérurgique 3, que l'on admettra être ici une brame d'acier. A la sortie de la lingotière, la brame 3, encore liquide à coeur 4, mais déjà solidifiée en périphérie 5 suite à son contact avec la paroi intérieure refroidie de la lingotière, achève de se solidifier complètement au cours de sa progression selon l'axe de coulée S au travers des étages inférieurs de l'installation de coulée notamment par projection d'eau directement à sa surface. L'arrivée du métal "neuf" en lingotière se fait par une busette immergée 6 dont la partie supérieure, non visible sur la figure, est fixée autour d'un orifice de coulée ménagé dans le fond d'un répartiteur placé à distance au-dessus et dont la partie basse est immergée en lingotière. Cette partie inférieure comporte des ouïes de sortie 7, 8 débouchant sous la surface libre 9 du métal liquide recouverte par un matelas 10 de laitier de couverture. Comme on le voit, ces ouïes de sortie, orientées selon le plan de coulée principal, sont de deux catégories différenciées:

    • des ouïes principales 7 inclinées vers le bas et délivrant la majeure partie du débit d'acier alimentant la lingotière par des jets 11 selon une direction d'ensemble placée dans le plan principal de coulée (le plan de la figure) et allant globalement vers le bas de la lingolière;
    • des ouïes secondaires 8 placées au-dessus, inclinées vers le haut et délivrant plutôt dans cette direction le solde du débit de métal par des jets 12 apportant à la surface 9 un appoint de chaleur nécessaire pour éviter des phénomènes de solidification parasites sur le ménisque (cornes de solidification, etc..)..
    An ingot mold 1, made of copper or a copper alloy vigorously cooled by a circulation of water on its outer wall, receives from above a certain flow of molten metal 2 which it discharges downwards in the form of a half - steel product 3, which we will admit to be here a slab of steel. At the outlet of the mold, the slab 3, still liquid at the core 4, but already solidified at the periphery 5 following its contact with the cooled inner wall of the mold, completes to solidify completely during its progression along the axis flow S through the lower stages of the casting installation, in particular by spraying water directly on its surface. The arrival of the "new" metal in the mold is done by a submerged nozzle 6, the upper part of which, not visible in the figure, is fixed around a pouring orifice formed in the bottom of a distributor placed at a distance above and whose lower part is immersed in an ingot mold. This lower part comprises outlet openings 7, 8 opening out under the free surface 9 of the liquid metal covered by a mattress 10 of covering slag. As we can see, these outlets, oriented according to the main casting plane, are of two differentiated categories:
    • main openings 7 inclined downwards and delivering the major part of the steel flow supplying the ingot mold by jets 11 in an overall direction placed in the main casting plane (the plane of the figure) and going generally towards the bottom of the mold;
    • secondary vents 8 placed above, inclined upward and rather delivering in this direction the balance of the metal flow by jets 12 bringing to the surface 9 an additional heat necessary to avoid parasitic solidification phenomena on the meniscus ( solidification horns, etc.).

    On rappelle que l'on entend par "plan de coulée principal" le plan médian vertical P passant par l'axe de coulée S au centre de la lingotière et parallèle aux grandes faces 22 de celle-ci. En l'espèce, les figures 1 et 5 sont précisément dans le plan de coulée principal P. L'autre plan analogue, mais parallèle aux petites faces latérales 13 de la lingotière, est lui qualifié de plan de coulée secondaire. Les figures 3a et 3b sont dans le plan de coulée secondaire.Remember that the term "main casting plane" means the vertical median plane P passing through the casting axis S in the center of the mold and parallel to the large faces 22 of it. In this case, Figures 1 and 5 are precisely in the casting plane principal P. The other analogous plane, but parallel to the small lateral faces 13 of the ingot mold, is he called secondary casting plan. Figures 3a and 3b are in the secondary flow plan.

    La loi de conservation des flux "matière" impose bien entendu l'égalité entre le débit de métal extrait par le dessous de la lingotière et celui, intégralement liquide, entrant dans la lingotière par la busette 6. Comme la vitesse d'extraction V est un paramètre de la coulée, c'est elle qui, pour une section de produit 3 donnée, impose le débit entrant, donc la vitesse de sortie du métal liquide hors des ouïes de la busette. Comme on l'a déjà dit, si l'installation de coulée est à haute productivité (seuil de vitesse d'extraction V de l'ordre de 1,5 m/mn environ), les flux de recirculation, qui inévitablement s'établissent en lingotière en raison de l'importance de l'écart entre la vitesse d'extraction et celle, cent fois supérieure, des jets de sortie du métal hors des ouïes de la busette, deviennent vite très vigoureux. Des boucles de recirculation violentes et turbulentes, dopées par les réflexions des jets de métal contre les petites faces 13 de la lingotière, viennent alors perturber fortement la surface libre 9. Ces perturbations sont nuisibles et doivent être atténuées, voire éliminées. Mais, cette atténuation ne doit pas mettre en cause l'apport calorifique à la surface libre 9 véhiculé par les jets secondaires 12. Comme le régime de fonctionnement d'une machine de coulée continue est avant tout de type "transitoire" du fait notamment des variations de la vitesse de coulée, c'est donc en quasi-permanence que cet équilibre recherché entre le besoin d'une surface libre calme et plate, et d'une surface libre réchauffée par du métal en fusion "neuf" venant de la busette est remis en question.The law for the conservation of "material" flows naturally imposes equality between the flow rate of metal extracted from below the ingot mold and that, entirely liquid, entering in the ingot mold by the nozzle 6. As the extraction speed V is a parameter of the flow, it is it which, for a given product section 3, imposes the incoming flow, therefore the speed of exit of the liquid metal from the vents of the nozzle. As we said before, if the casting installation is highly productive (extraction speed threshold V of the order about 1.5 m / min), the recirculation flows, which inevitably settle in ingot mold due to the importance of the difference between the extraction speed and that, one hundred times higher, metal jets out of the nozzle holes, quickly become very vigorous. Violent and turbulent recirculation loops, doped by reflections of the metal jets against the small faces 13 of the mold, then come strongly disturb the free surface 9. These disturbances are harmful and must be mitigated or even eliminated. However, this reduction should not call into question the contribution calorific at the free surface 9 conveyed by the secondary jets 12. As the regime of operation of a continuous casting machine is above all of the "transient" type from in particular varies the casting speed, so it's almost always that this sought-after balance between the need for a calm and flat free surface, and a surface free heated by "new" molten metal coming from the nozzle is questioned.

    C'est la raison pour laquelle que, conformément à l'invention, sur chaque grande face 22 de la lingotière, une unité inductrice, constituée par un couple d'inducteurs électromagnétiques 14, 15, est disposée en regard de la partie terminale de la busette. Ces deux inducteurs sont appariés de manière à produire chacun un pôle magnétique faisant face à l'autre, de signe opposé afin de créer un champ magnétique traversant, perpendiculaire aux grandes faces 22. Comme on le voit sur les figures 1 et 3, ce champ traversant est localisé en "M" dans la partie basse de l'entrefer afin de "couvrir" les ouïes de la catégorie 7 situées à l'extrémité basse du corps de la busette 6. Toutefois, ces inducteurs sont conçus de manière que leurs pôles magnétiques puissent être déplacés ensemble dans l'entrefer. Ici, le déplacement se fera selon la hauteur de la lingotière, puisque les conducteurs 16...17' sont disposés à l'horizontale. Ce déplacement conjoint des pôles de l'inducteur, sur une distance de l'ordre de 10 ou 15 cm environ, provoquera un déplacement correspondant du champ magnétique traversant dans l'entrefer, donc une modification corrélative des conditions magnétiques locales au niveau des ouïes de sortie différenciées 7 et 8 de la busette. La conséquence est une redistribution recherchée des débits de métal sortant de ses deux catégories d'ouïes, le débit total restant lui inchangé ou quasiment inchangé. Ainsi, sur la figure 3, on a représenté en M une position initiale basse du champ magnétique dans l'entrefer, et en N, une position finale haute après une opération de déplacement vertical sur une distance "d" en direction des ouïes 8 délivrant des jets de métal vers le haut.This is the reason why, according to the invention, on each large face 22 of the ingot mold, an inductor unit, constituted by a pair of inductors electromagnetic 14, 15, is arranged opposite the end portion of the nozzle. These two inductors are paired so as to each produce a magnetic pole making facing each other, of opposite sign in order to create a crossing magnetic field, perpendicular to the large faces 22. As can be seen in Figures 1 and 3, this field through is located in "M" in the lower part of the air gap in order to "cover" the gills of category 7 located at the lower end of the body of the nozzle 6. However, these inductors are designed so that their magnetic poles can be moved together in the air gap. Here, the displacement will be done according to the height of the mold, since the conductors 16 ... 17 'are arranged horizontally. This joint displacement poles of the inductor, over a distance of about 10 or 15 cm approximately, will cause a corresponding displacement of the magnetic field passing through the air gap, therefore a correlative modification of the local magnetic conditions at the level of the outlets differentiated 7 and 8 of the nozzle. The consequence is a sought-after redistribution of metal flows leaving its two categories of gills, the total flow remaining unchanged or almost unchanged. Thus, in FIG. 3, an initial position has been represented at M low magnetic field in the air gap, and in N, a high end position after a vertical displacement operation over a distance "d" towards the openings 8 delivering metal jets up.

    Le déplacement du champ magnétique peut être obtenu au moyen d'un couple d'inducteurs de type "électroaimant", dotés donc d'un pôle magnétique saillant servant de support à un conducteur filaire bobiné autour, et montés mobile en translation sur un châssis solidaire de l'installation de coulée. Cette réalisation nécessite donc un déplacement physique de l'unité inductrice.The displacement of the magnetic field can be obtained by means of a couple "electromagnet" type inductors, therefore with a protruding magnetic pole serving as support for a wired conductor wound around, and mounted movable in translation on a chassis secured to the casting installation. This realization therefore requires a physical displacement of the inducing unit.

    Quand les conditions prévalantes le permettent, on optera de préférence pour un champ magnétique déplaçable dans un entrefer fixe. On sait qu'une telle possibilité est offerte par une unité inductrice, telle que schématisée sur la figure 2, constituée, en regard l'un de l'autre de part et d'autre des grandes faces 22 de la lingotière, par un deux inducteurs à pluri-enroulements de phases de type " à champ magnétique glissant". L'inducteur représenté ici est un inducteur plan de type "stator de moteur linéaire" et biphasé (donc à deux enroulements de phase). Ses conducteurs sont des barres rectilignes de cuivre 16, 17, 16', 17', au nombre de quatre, parallèles entre elles, espacées et disposées horizontalement. Chaque enroulement est composé de deux barres reliées entre elle en série-opposition de manière que le courant électrique les parcourt dans des sens opposés. Les barres reliées peuvent être indifféremment des barres immédiatement voisines, telles que 17 avec 16' et 16 avec 17' (inducteur à pôles adjacents), ou décalées, telles que 16 avec 16' et 17 avec 17' (inducteur à pôles répartis), comme représenté sur la figure.When prevailing conditions allow, we will preferably opt for a movable magnetic field in a fixed air gap. We know that such a possibility is offered by an inductor unit, as shown schematically in Figure 2, constituted, opposite one on the other on both sides of the large faces 22 of the mold, by a two inductors with multi-winding phases of the "sliding magnetic field" type. The inductor shown here is a flat inductor of the "linear motor stator" type and two-phase (therefore with two phase windings). Its conductors are straight bars of copper 16, 17, 16 ', 17', four in number, mutually parallel, spaced and arranged horizontally. Each winding is composed of two bars connected between it in series-opposition so that the electric current flows through them in directions opposed. The connected bars can be immediately bars neighboring, such as 17 with 16 'and 16 with 17' (inductor with adjacent poles), or offset, such as 16 with 16 'and 17 with 17' (inductor with distributed poles), as shown in the Fig.

    Il importe cependant que, quelque soit la configuration choisie, chaque enroulement de phase soit relié à une alimentation électrique élémentaire à courant continu (ou redressé) et à elle seule et qui soit indépendante de celle de l'autre enroulement. Ces alimentations élémentaires, symbolisées en 18 et 19 sur la figure 2, peuvent avoir leur neutre mis en commun pour des raisons de commodité. Elles sont intégrées dans une unité d'alimentation électrique 20 pourvue de moyens 2 la et 21b de réglage autonome des intensités des courants délivrés par chaque alimentation élémentaire 18, 19 afin de pouvoir, par exemple, faire passer un courant d'intensité maximale dans un enroulement pendant que l'autre est inactivé (intensité nulle), et réciproquement, ainsi que tous les réglages intermédiaires. C'est dans ces conditions que l'inducteur-plan 14 (15) pourra créer, non plus un champ glissant comme il le fait ordinairement, mais un champ magnétique statique, dont le pôle magnétique qui le délivre pourra être déplacé sur la face active de l'inducteur selon une direction orthogonale aux conducteurs, simplement en modifiant convenablement les intensités de courant dans les deux enroulements. On trouvera d'ailleurs au besoin une description plus détaillée de ce type d'inducteur et de son mode de fonctionnement en champ glissant ainsi qu'en champ statique dans la Demande de brevet international PCT publiée sous le n° WO 99/30856 au nom du demandeur.However, it is important that, whatever the configuration chosen, each phase winding is connected to an elementary current power supply continuous (or straightened) and alone and which is independent of that of the other winding. These elementary power supplies, symbolized in 18 and 19 in FIG. 2, may have their neutral pooled for convenience. They are integrated in an electrical power supply unit 20 provided with means 2 la and 21b of autonomous adjustment of the intensities of the currents delivered by each power supply elementary 18, 19 in order to be able, for example, to pass a current of intensity maximum in one winding while the other is inactive (zero intensity), and conversely, as well as all the intermediate settings. It is under these conditions that the field inductor 14 (15) will no longer be able to create a sliding field as it does ordinarily, but a static magnetic field, including the magnetic pole which can be moved on the active face of the inductor in a direction orthogonal to the conductors, simply by suitably modifying the intensities of current in the two windings. A more detailed description will be found if necessary. detailed description of this type of inductor and its operating mode in sliding field as well as in the static field in the PCT International Patent Application published under the WO 99/30856 in the name of the applicant.

    Sur la figure 3, la position basse "M" du pôle magnétique correspond à un courant maximal dans l'enroulement 16,16', associé à un courant nul dans l'enroulement 17,17'. A l'inverse, la position haute "N" de la figure 3 correspond à un courant maximal dans l'enroulement 17,17' associé à un courant nul dans l'enroulement 16,16'. On peut bien entendu ajuster la localisation du pôle de l'inducteur à un niveau quelconque entre ces deux positions extrêmes en combinant les intensités des courants à l'aide des moyens de réglage 21 équipant l'alimentation électrique 20.In FIG. 3, the low position "M" of the magnetic pole corresponds to a current maximum in the winding 16.16 ', associated with a zero current in the winding 17.17'. AT conversely, the high position "N" in FIG. 3 corresponds to a maximum current in the winding 17,17 'associated with a zero current in the winding 16,16'. We can well heard adjusting the location of the inductor pole to any level between these two extreme positions by combining the intensities of the currents using the means of setting 21 fitted to the power supply 20.

    On voit bien sur la figure 4 que les deux inducteurs-plan appariés 14 et 15 sont configurés de manière que leurs pôles magnétiques respectifs en regard l'un de l'autre aient des polarités opposées. De la sorte, le champ magnétique de l'un s'additionne au champ magnétique de l'autre en tout point de l'entrefer entre les deux inducteurs. La configuration est du type "à champ traversant": comme l'illustrent les traits fléchés B, les lignes de force joignent les pôles magnétiques d'un inducteur à l'autre en traversant perpendiculairement le plan principal de coulée P, donc la direction des jets de métal en fusion sortant de la busette.It can be seen in FIG. 4 that the two paired plane inductors 14 and 15 are configured so that their respective magnetic poles facing each other have opposite polarities. In this way, the magnetic field of one adds to the magnetic field of the other at any point in the air gap between the two inductors. The configuration is of the "through field" type: as illustrated by the arrow marks B, the lines of force join the magnetic poles from one inductor to another while crossing perpendicularly to the main casting plane P, therefore the direction of the metal jets in fusion coming out of the nozzle.

    Vu sous un autre angle, on retrouve ce type de configuration sur la figure 3. Le champ magnétique traversant créé par les pôles de chaque inducteur 14, 15 peut être déplacé en hauteur d'une distance "d", depuis une localisation basse "M" où l'action magnétique de freinage sur les écoulements des ouïes principales 7 est maximale, jusqu'à une localisation haute "N" correspondant à une action magnétique de freinage affaiblie sur les ouïes principales 7, mais renforcée sur les ouïes secondaires 8.Seen from another angle, we find this type of configuration in Figure 3. The through magnetic field created by the poles of each inductor 14, 15 can be displaced in height by a distance "d", from a low location "M" where the action magnetic braking on the flows of the main openings 7 is maximum, up to a high "N" location corresponding to a weakened magnetic braking action on the main openings 7, but reinforced on the secondary openings 8.

    Il va de soi que l'invention n'est pas limitée aux réalisations exemplifiées ci-avant, mais s'étend à de nombreuses variantes ou équivalents dans la mesure où est respectée sa définition donnée dans les revendications jointes.It goes without saying that the invention is not limited to the embodiments exemplified above, but extends to many variants or equivalents as long as its definition given in the appended claims.

    On aura compris en effet que si la busette doit comporter des ouïes de sortie dans le plan principal de coulée de la lingotière pour que l'invention puisse s'appliquer, elle peut également être pourvue d'autres ouïes placées ailleurs, par exemple en diagonale en direction des angles de la lingotière. En fait, plus la direction des jets de sortie est orthogonale aux lignes de force du champ, plus l'invention produit ses effets, puisque l'efficacité de l'action électromagnétique obtenue est directement proportionnelle au produit vectoriel entre le champ magnétique et le vecteur vitesse des jets à leur sortie des ouïes de la busette.It will be understood in fact that if the nozzle must have outlet openings in the main casting plane of the ingot mold so that the invention can be applied, it can also be provided with other gills placed elsewhere, for example diagonally in direction of the angles of the mold. In fact, the more direction the exit jets are orthogonal to the lines of force of the field, the more the invention produces its effects, since the efficiency of the electromagnetic action obtained is directly proportional to the vector product between the magnetic field and the velocity vector of the jets as they exit the nozzle openings.

    De même, si la conception de l'invention a été motivée principalement par le souci de pouvoir mieux gérer les apports caloriques à la surface libre à partir du métal en fusion lui, même arrivant en lingotière et, par conséquent a été axée préférentiellement sur des busettes dotées d'ouïes de sorties dirigées certaines vers le bas et les autres vers le haut l'invention n'en demeure pas moins d'application générale à toute busette dont les ouïes de sortie n'ont pas toutes la même direction. En effet, dès que deux ouïes ont des directions de sortie différentes, même faiblement différentes, par exemple de quelques degrés d'angle seulement, l'invention en toute rigueur s'applique. Elle s'applique toutefois dans la mesure où ces deux ouïes sont tout de même suffisamment éloignées l'une de l'autre pour permettre à un champ magnétique traversant d'en couvrir une et pas l'autre, ou du moins lui permettre de les couvrir toutes deux mais avec des valeurs d'induction qui, au même moment, sont passablement différentes sur l'une et sur l'autre. C'est en effet, comme on l'aura sans doute compris, la possibilité d'avoir un écart de l'intensité du champ entre deux points de l'espace intérieur d'une lingotière de coulée continue de produits à format allongé qui est à la base même de l'idée mère de l'invention.Similarly, if the conception of the invention was motivated mainly by the concern to be able to better manage the caloric contributions to the free surface from the molten metal himself, even arriving in an ingot mold and, consequently, was preferentially focused on nozzles with outlet openings directed some downwards and others upwards the invention nevertheless remains of general application to any nozzle including the gills of not all exit in the same direction. Indeed, as soon as two gills have directions different, even slightly different, for example a few degrees angle only, the invention strictly applies. However, it applies in the as these two gills are still far enough apart from each other to allow a traversing magnetic field to cover one and not the other, or at least allow it to cover both but with induction values which at the same moment, are quite different on one and on the other. It is indeed, as we will probably have understood, the possibility of having a difference in the intensity of the field between two points of the interior space of a mold for continuous casting of format products elongated which is at the very basis of the mother idea of the invention.

    Ainsi, bien que l'invention donne de meilleurs résultats dans le cas des busettes de type "caisson" vu précédemment, elle s'accommode également de busettes droites, l'essentiel étant que les busettes immergées dont on se sert pour la coulée présentent des ouïes de sortie différenciées en au moins deux catégories par les directions -le plus 5 souvent vers le haut et vers le bas- qu'elles impriment aux jets de métal en fusion qui en sortent parallèlement aux grandes faces. Autrement-dit, l'invention s'applique par exemple également aux busettes droites ayant des ouïes latérales différenciées haut-bas sur le fût de la busette. Thus, although the invention gives better results in the case of the nozzles type "box" seen above, it also accommodates straight nozzles, the main thing is that the submerged nozzles used for casting have outlet openings differentiated into at least two categories by directions - the most 5 often upwards and downwards - which they imprint on the jets of molten metal which come out parallel to the large faces. In other words, the invention applies by example also for straight nozzles with differentiated side vents up-down on the barrel of the nozzle.

    D'autre part, on a supposé implicitement ci-avant que l'intensité B du champ magnétique reste constante. Toutefois, comme déjà indiqué, elle peut fort bien varier, en modifiant l'intensité des courants d'alimentation, le champ lui pouvant être déplacé en même temps dans l'entrefer, ou séparément.On the other hand, it has been implicitly assumed above that the intensity B of the field magnetic remains constant. However, as already indicated, it can very well vary, in modifying the intensity of the supply currents, the field being able to be moved in same time in the air gap, or separately.

    De même, comme le montre la figure 5, l'inducteur 14 (de même bien entendu l'inducteur 15) peut être dédoublé en deux parties identiques 14a et 14b placées côte à côte sur la même face de la lingotière de part et d'autre de l'axe de coulée S sur lequel est d'ailleurs classiquement centrée la busette de coulée. On vise de cette manière à "couvrir" par un champ magnétique les zones latérales de la busette indépendamment l'une de l'autre, afin de pouvoir agir sélectivement sur les jets de métal coulé 11,12 sortant de ces zones. Par des réglages autonomes des parties inductives 14a et 14b, on parvient ainsi à mieux symétriser encore les écoulements dans la lingotière car on intervient sur eux au moment même où ils sortent de la busette. Ce résultat, bien entendu, est obtenu en complément à l'effet premier de l'invention qui demeure la répartition entre les différents orifices de la busette du débit total sortant de métal par un réglage en hauteur du pôle magnétique sur chaque partie inductive 14a et 14b. Dans cette variante, chaque partie inductive est alimentée en courant par sa propre alimentation élémentaire (non représentée) de manière à pouvoir pratiquer au besoin des réglages en hauteur différents du pôle magnétique sur chacune d'elles, ainsi que des modifications séparées des intensités de courant qui les parcourent.Similarly, as shown in FIG. 5, the inductor 14 (likewise of course inductor 15) can be split into two identical parts 14a and 14b placed side by side side on the same face of the ingot mold on either side of the casting axis S on which is moreover, conventionally centered the pouring nozzle. In this way we aim to "cover" by a magnetic field the lateral zones of the nozzle independently of one of the other, in order to be able to act selectively on the cast metal jets 11,12 leaving these areas. By autonomous adjustments of the inductive parts 14a and 14b, we thus arrive at to better symmetrize the flows in the ingot mold because we intervene on them at the moment they get out of the nozzle. This result, of course, is obtained in complement to the primary effect of the invention which remains the distribution between the different orifices of the nozzle for the total flow leaving the metal by adjusting the height of the pole magnetic on each inductive part 14a and 14b. In this variant, each part inductive is supplied with current by its own elementary power supply (not shown) so that different height adjustments can be made if necessary of the magnetic pole on each of them, as well as separate modifications of the intensities of current flowing through them.

    Par ailleurs, en lieu et place d'inducteurs du type "à champ glissant", on pourra opter, non seulement pour des électroaimants, comme déjà mentionné, mais encore pour des aimants permanents, naturels ou industriels.In addition, instead of inductors of the "sliding field" type, we can opt not only for electromagnets, as already mentioned, but also for permanent, natural or industrial magnets.

    En outre, l'expression "alimentations élémentaires en courant continu" utilisée dans l'exposé signifie, non nécessairement une addition d'alimentations unitaires structurellement indépendantes, mais encore une alimentation polyphasée unique, à deux ou trois phases, et à fréquence réglable, que l'on règle à fréquence nulle pour obtenir un courant continu. Les alimentations électriques polyphasées de ce type sont bien connues. Elles sont du type à onduleur à seuil de hachage réglable et sont ordinairement utilisées pour activer des moteurs électriques à champ magnétique tournant ou glissant. La mise en fonction d'une telle alimentation électrique pour alimenter les enroulements de l'inducteur 14, à raison d'une phase par enroulement, consiste à régler l'onduleur à la fréquence nulle, en effectuant de tels réglages à des moments choisis afin que les intensités des courants dans chaque phase soient, à ces moments-là, celles que l'on souhaite obtenir dans les enroulements reliés à ces phases.In addition, the expression "elementary direct current power supplies" used in the presentation means, not necessarily an addition of unit feeds structurally independent, but still a single polyphase supply, two or three phases, and adjustable frequency, which is set at zero frequency to obtain a direct current. Polyphase power supplies of this type are well known. They are of the inverter type with adjustable chopping threshold and are commonly used to activate electric motors with rotating or sliding magnetic field. Setting as a function of such a power supply to supply the windings of inductor 14, at the rate of one phase per winding, consists in adjusting the inverter to the zero frequency, making such adjustments at selected times so that the intensities of the currents in each phase are, at these times, those which one wishes to obtain in the windings connected to these phases.

    On rappelle encore que si l'invention trouve un terrain d'application privilégié avec la coulée continue de brames d'acier pour laquelle elle a d'ailleurs été initialement conçue, elle n'en demeure pas moins applicable à la coulée continue des métaux en général, et à la coulée continue des brames minces en particulier.It is also recalled that if the invention finds a privileged field of application with the continuous casting of steel slabs for which it was also originally designed, it nonetheless remains applicable to the continuous casting of metals in in general, and in the continuous casting of thin slabs in particular.

    Claims (12)

    1. An apparatus for feeding a mold of a plant for the continuous casting of products of rectangular cross section, such as slabs, with molten metal, which comprises a submerged entry nozzle (6) provided with outlets for the molten metal which lie in, or substantially in, the main casting plane (P) parallel to the broad faces of the mold, these outlets differing in their direction of outflow and falling within at least two separate types (7, 8) ; and an inductive unit placed facing the broad faces of the mold in order to produce thereon magnetic poles of opposite sign facing each other on each side of said main casting plane (P) characterized in that the said inductive unit (14, 15) has its gap substantially surrounding the nozzle (6), and delivers a traversing magnetic field covering the outlets of at least one (7) of said separate types (7, 8); and in that the said apparatus comprises means (20, 21) for adjusting the relative intensity of said magnetic field, in the region of the outlets of said type (7) which is covered, with respect to the outlets of the other type (8), so as to be able to modify the distribution of the total flow of molten metal between all the outlets of said nozzle (6).
    2. The apparatus as claimed in claim 1, characterized in that said inductive unit is an electromagnetic unit consisting of at least one electromagnet.
    3. The apparatus as claimed in claim 1, characterized in that said inductive unit consists of inductors (14, 15) having a plurality of phase windings of the "traveling field" type, facing each other on each side of said main casting plane (P), and of an associated power supply which supplies each of said windings separately with DC current and in that the means (20, 21) for adjusting the relative intensity of the magnetic field comprise means for moving the location of the magnetic poles in the gap of said electromagnetic unit.
    4. The apparatus as claimed in claim 1, characterized in that said inductive unit consists of at least one permanent magnet.
    5. The apparatus as claimed in claim 2 or 3, characterized in that said means for adjusting the relative intensity of the magnetic field comprise a device for varying the intensity of the electric current supplied to the inductive unit.
    6. The apparatus as claimed in claim 2 or 4, characterized in that said means for adjusting the relative intensity of said magnetic field comprise an arrangement in which the magnets or electromagnets can move in a sliding manner.
    7. The apparatus as claimed in claim 3, characterized in that said means for modifying the location of the magnetic poles in the gap consist of means for separately adjusting the intensities of the DC electric currents individually supplying the phase windings of said inductors (14, 15).
    8. The apparatus as claimed in any one of claims 1 to 7, characterized in that said inductive unit consists, on each side of the main casting plane (P), of two similar entities (14a, 14b) placed side by side on each side of the casting axis.
    9. The apparatus as claimed in any one of the preceding claims, characterized in that the submerged entry nozzle is a nozzle provided, in the main casting plane (P), with lower main outlets (7) directed toward the bottom of the mold and with upper secondary outlets (8) directed upward.
    10. The apparatus as claimed in claim 9, characterized in that the lower main outlets form one and the same outlet.
    11. A process for operating an apparatus as claimed in claim 1 so as to feed a mold of a plant for the continuous casting of products of rectangular cross section with molten metal, characterized in that the relative intensity of the magnetic field produced by the magnetic poles of the inductive unit is adjusted by moving the position of the magnetic poles.
    12. A process for operating an apparatus as claimed in claim 1 so as to feed a mold of a plant for the continuous casting of products of rectangular cross section with molten metal, characterized in that the relative intensity of the magnetic field produced by the magnetic poles of the inductive unit is adjusted by modifying the intensity of the electric current supplying said inductive unit.
    EP01903983A 2000-02-29 2001-01-29 Equipment for supplying molten metal to a continuous casting ingot mould and method for using same Expired - Lifetime EP1259343B1 (en)

    Applications Claiming Priority (3)

    Application Number Priority Date Filing Date Title
    FR0002501 2000-02-29
    FR0002501A FR2805483B1 (en) 2000-02-29 2000-02-29 EQUIPMENT FOR SUPPLYING MOLTEN METAL TO A CONTINUOUS CASTING LINGOTIERE, AND METHOD OF USING SAME
    PCT/FR2001/000263 WO2001064373A1 (en) 2000-02-29 2001-01-29 Equipment for supplying molten metal to a continuous casting ingot mould and method for using same

    Publications (2)

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    EP1259343A1 EP1259343A1 (en) 2002-11-27
    EP1259343B1 true EP1259343B1 (en) 2003-09-03

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    US (1) US20020179281A1 (en)
    EP (1) EP1259343B1 (en)
    JP (1) JP4580135B2 (en)
    KR (1) KR100751021B1 (en)
    CN (1) CN1192833C (en)
    AT (1) ATE248672T1 (en)
    AU (1) AU771606B2 (en)
    BR (1) BR0108754B1 (en)
    CA (1) CA2398724C (en)
    DE (1) DE60100707T2 (en)
    ES (1) ES2206399T3 (en)
    FR (1) FR2805483B1 (en)
    RU (1) RU2248859C2 (en)
    TW (1) TWI290070B (en)
    WO (1) WO2001064373A1 (en)

    Families Citing this family (7)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    JP4585504B2 (en) * 2006-12-05 2010-11-24 新日本製鐵株式会社 Method for continuous casting of molten metal
    MY166993A (en) * 2010-07-02 2018-07-27 Vesuvius Crucible Co Submerged entry nozzle
    JP5669509B2 (en) * 2010-07-16 2015-02-12 高橋 謙三 Molding device for continuous casting with stirring device
    RU2741611C1 (en) * 2020-02-27 2021-01-27 Федеральное государственное бюджетное образовательное учреждение высшего образования "Комсомольский-на-Амуре государственный университет" (ФГБОУ ВО "КнАГУ") Device for steel supply and mixing in crystallizer of continuous casting plant
    CN112276025B (en) * 2020-10-28 2022-03-08 安徽工业大学 Device and method for inhibiting vortex formation at ladle nozzle by adding electromagnetic field
    RU2760696C1 (en) * 2021-02-09 2021-11-29 Федеральное государственное бюджетное образовательное учреждение высшего образования "Комсомольский-на-Амуре государственный университет" (ФГБОУ ВО "КнАГУ") Apparatus for supplying and mixing steel in the crystalliser of a continuous casting unit
    CN113102686B (en) * 2021-04-01 2022-11-29 杭州红山磁性材料有限公司 Alnico integral magnetic steel orientation casting method

    Family Cites Families (12)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    US4949778A (en) * 1987-12-16 1990-08-21 Kawasaki Steel Corporation Immersion nozzle for continuous casting
    JP2773154B2 (en) * 1988-09-30 1998-07-09 日本鋼管株式会社 Steel continuous casting method
    SE500745C2 (en) * 1991-01-21 1994-08-22 Asea Brown Boveri Methods and apparatus for casting in mold
    LU88034A1 (en) * 1991-11-13 1993-05-17 Centrem Sa Electromagnetic stirring process in continuous casting
    IT1267242B1 (en) * 1994-05-30 1997-01-28 Danieli Off Mecc UNLOADER FOR THIN SLABS
    JPH08257692A (en) * 1995-03-24 1996-10-08 Nippon Steel Corp Production of continuously cast slab and immersion nozzle for continuous casting
    JP3410607B2 (en) * 1996-04-23 2003-05-26 新日本製鐵株式会社 Continuous casting method and immersion nozzle for continuous casting
    IT1290931B1 (en) * 1997-02-14 1998-12-14 Acciai Speciali Terni Spa FEEDER OF MELTED METAL FOR INGOT MACHINES OF CONTINUOUS CASTING MACHINES.
    JPH10263777A (en) * 1997-03-26 1998-10-06 Nkk Corp Method for continuously casting steel
    JPH1147897A (en) * 1997-07-31 1999-02-23 Nippon Steel Corp Immersion nozzle for continuously casting thin and wide cast slab
    FR2772294B1 (en) * 1997-12-17 2000-03-03 Rotelec Sa ELECTROMAGNETIC BRAKING EQUIPMENT OF A MOLTEN METAL IN A CONTINUOUS CASTING SYSTEM
    JPH11197807A (en) * 1998-01-08 1999-07-27 Kawasaki Steel Corp Immersion nozzle for casting cast slab having plural layers and production of plural layer cast slab

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    Publication number Publication date
    FR2805483A1 (en) 2001-08-31
    RU2002122721A (en) 2004-02-20
    TWI290070B (en) 2007-11-21
    KR100751021B1 (en) 2007-08-22
    AU771606B2 (en) 2004-04-01
    BR0108754A (en) 2002-12-10
    CN1392810A (en) 2003-01-22
    DE60100707D1 (en) 2003-10-09
    JP4580135B2 (en) 2010-11-10
    JP2003525129A (en) 2003-08-26
    US20020179281A1 (en) 2002-12-05
    FR2805483B1 (en) 2002-05-24
    ES2206399T3 (en) 2004-05-16
    KR20020086913A (en) 2002-11-20
    RU2248859C2 (en) 2005-03-27
    ATE248672T1 (en) 2003-09-15
    CA2398724A1 (en) 2001-09-07
    AU3192501A (en) 2001-09-12
    CN1192833C (en) 2005-03-16
    DE60100707T2 (en) 2004-07-29
    EP1259343A1 (en) 2002-11-27
    BR0108754B1 (en) 2010-06-15
    WO2001064373A1 (en) 2001-09-07
    CA2398724C (en) 2008-10-07

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