EP0340057A1 - Protecting device for induction poles and inductor provided with this device - Google Patents

Protecting device for induction poles and inductor provided with this device Download PDF

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Publication number
EP0340057A1
EP0340057A1 EP89400908A EP89400908A EP0340057A1 EP 0340057 A1 EP0340057 A1 EP 0340057A1 EP 89400908 A EP89400908 A EP 89400908A EP 89400908 A EP89400908 A EP 89400908A EP 0340057 A1 EP0340057 A1 EP 0340057A1
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EP
European Patent Office
Prior art keywords
exchanger
tubes
inductor
pole
poles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP89400908A
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German (de)
French (fr)
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EP0340057B1 (en
Inventor
Marc Buffenoir
René Pierret
Jean Hellegouarc'h
Gérard Prost
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Rotelec SA
Original Assignee
Institut de Recherches de la Siderurgie Francaise IRSID
Rotelec SA
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Publication of EP0340057A1 publication Critical patent/EP0340057A1/en
Application granted granted Critical
Publication of EP0340057B1 publication Critical patent/EP0340057B1/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B1/00—Details of electric heating devices
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/36—Coil arrangements
    • H05B6/42—Cooling of coils
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
    • F28D7/04—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being spirally coiled

Definitions

  • the present invention relates to a device for protecting the poles of inductors, in particular used for heating or reheating metallic products by induction.
  • electromagnetic inductors with traversing field.
  • Such inductors are described in particular in document FR 2583249.
  • they comprise a C- shaped magnetic yoke, the ends of the C forming the two poles of the inductor, carrying the induction coils, being placed on either side of the product to be reheated.
  • the poles must be as close as possible to the product. This causes the poles and the induction coils which they carry to be subjected to the strong thermal radiation of the hot product.
  • the inductors and especially their poles are subjected to chemical and mechanical attack, for example heavy watering, scale deposit, risk of shock with the heated product.
  • the object of the present invention is to ensure the protection of the poles of inductors subjected to thermal, mechanical and chemical stresses, in a reliable and durable manner, without causing loss of heating efficiency.
  • Another aim is to solve the various problems mentioned above.
  • the present invention has for object a device for protecting, in particular thermal, the poles of an electromagnetic inductor.
  • this device comprises a heat exchanger formed by one or more non-magnetic metal tubes substantially coplanar arranged to allow the circulation of a cooling fluid and in an arrangement such that there is at most a single electrical junction between any two tubes or tube elements, so as to limit the electrical loopbacks between tubes or portions of neighboring tubes or not.
  • electrical junction here relates to direct contact or low resistance connections, to the exclusion of high resistance connections existing in materials which are not perfect insulators.
  • the exchanger is shaped according to a succession of alternately inverted hairpins.
  • the exchanger is shaped in a spiral to one branch or more.
  • the exchanger is supported and fixed on a rigid electrically insulating plate, and coated with refractory concrete, the assembly forming a composite panel of small thickness, of dimensions sufficient to cover the pole face of each pole.
  • the device according to the invention makes it possible in fact to reconcile two divergent incidence functions: on the one hand, the thermal protection of the pole by forced cooling by means of a metal tube exchanger, on the other hand, the conservation of good heating efficiency of the inductor.
  • a set of metal tubes interposed between pole and product generally forms a screen which opposes the passage of magnetic flux and in which can be generated high intensity electric currents which have the effect of opposing the passage of flow and heat up the circuit where they are created.
  • the arrangement of the tubes according to the invention makes it possible to avoid these effects and to ensure maximum "transparency" of the intense magnetic field created by the inductor.
  • the invention also relates to an inductor provided with the pole protection device as described above, which will then advantageously be dimensioned and placed opposite each of the pole faces of which it follows the shape so as to cover them as well. as the induction coils and the insulators and cowlings, so as to achieve good sealing of the entire pole and its circuits.
  • Figure 1 a pole of a C- type inductor with hinged yoke, as described in document FR 2583249 to which reference may be made for more details on the general construction of the inductor. It is simply recalled here that in this type of inductor, intended in particular for reheating the edges of blanks of generally flat metal products, a second pole, similar to that shown in FIG. 1, is arranged opposite this, both poles forming the ends of a "C" shaped magnetic yoke which connects them.
  • the intense magnetic field created by the inductor has the effect of heating the product which passes between the two facing poles.
  • the induced powers are of the order of several hundred KW, which, brought to the surface of the cylinder head, corresponds to powers which can exceed 5 MW / m2.
  • the pole of Figure 1 has an induction coil 2 surrounding the end of the magnetic yoke 1.
  • a protective cover 3 surrounds the entire polar end (yoke and coil), a heat shield can be interposed between coil 2 and cover 3.
  • the composite plate 4 forming the protection device according to the invention is formed of a support plate 5 of rigid non-metallic material, electrically insulating, such as a material based on glass fiber, for example in "sillirite 64120" , a few millimeters thick.
  • the nut 8 of the screw 7 is placed in a counterbore made in the support plate 5, so as not to protrude from the surface thereof.
  • a sheet 9 of insulating material is glued under the plate 5, concealing the nuts 8 and thus guaranteeing the electrical isolation between the fixing screws 7.
  • the tubes 6 of the exchanger are coated in a refractory concrete 10 (for example the concrete based on silicon carbide marketed under the name of "morgan montex CIM 02").
  • a refractory concrete 10 for example the concrete based on silicon carbide marketed under the name of "morgan montex CIM 02". This concrete completely covers the tubes 6 and its low electrical conductivity makes it possible to limit any looping currents between neighboring pins.
  • this concrete is covered on one side with a plate of ceramic-ceramic material 11, or any other similar material, which has great resistance to heat and especially to thermal shock, combined with good mechanical resistance.
  • a plate of ceramic-ceramic material 11 or any other similar material, which has great resistance to heat and especially to thermal shock, combined with good mechanical resistance.
  • a ceramic textile fabric or an insulating coating (type coating) based on alumina or silica.
  • the composite plate 4 is fixed to the pole of the inductor by bolting, either directly on the cylinder head, or on additional supports arranged between coil and cowlings.
  • the thickness of the plate 4 is approximately 15 mm and its dimensions and shape are determined so as to cover the entire pole, up to the casing 3, a joint cover 12 being arranged around the plate 4 to prevent water infiltration or the ingress of dust or other solid bodies inside the enclosure 3.
  • FIG. 2 schematically represents a preferred arrangement of the tubes of the exchanger. This is here carried out in three independent circuits, which allows for example to adapt the intensity of cooling according to the areas covered by adjusting the flow rate of the cooling fluid, usually water.
  • This arrangement in "pins" makes it possible to cover the surface of the pole as well as possible, because it is easy to adapt the number and the length of the pins according to the shape of the surface to be covered.
  • the exchanger can have a spiral configuration as shown in Figures 3 and 4.
  • Figure 4 schematically shows a double inverted spiral arrangement with a single tube; the cooling fluid supply and return are indicated by the arrows A and R.
  • the arrangement in Figure 3 shows four spirals powered by a central power supply.
  • the supply is made by a pipe in the axis of the pole, through the cylinder head 1.
  • a central supply can also be carried out in the case of the arrangements in FIGS. 2 and 4, and has the advantage of participating in the cooling of the magnetic yoke.
  • the tubes are preferably made of non-magnetic stainless steel and for simplicity, of circular section. It is possible, in particular to reduce the thickness of the composite protection plate 4, to use tubes of flattened section, or even possibly of practically rectangular section.
  • Tubes of reduced thickness will be chosen, always with the aim of reducing any electrical currents generated by the magnetic field, by increasing the electrical resistance of said tubes.
  • the tubes which can moreover, instead of being coated with epoxy resin, as indicated above, be coated with an insulating film or coated with another insulating resin (polyester for example).
  • the protection device being essentially to form a heat shield protecting the pole and its accessories from the radiation of the heated product, we will seek to bring the tubes as close as possible to each other.
  • the use of a concrete having a fairly good thermal conductivity allows a diffusion in its mass of the heat received by its surface and therefore allows to obtain a cooling of said ceramic glass plate, which can thus be maintained at a temperature close to 700 ° C. for example, while the heated product is at more than 1000 ° C.
  • These blocks have a width equal to the distance between two neighboring tubes 6 and they have on their two longitudinal sides concavities 14 matching the section of the tubes so as to be able to be inserted between them to reconstitute the concrete coating overall.
  • the first block 13 ′ of each row has an extension 15 of its flat upper part.
  • the invention is not limited to the device and to its variants described above only by way of example.
  • provision may be made to have, in the same area, two or more tubes having this configuration, but arranged in parallel, each pin of a tube being nested in a pin formed by the other tube, and this alternately, all the pins of course remaining coplanar.
  • This arrangement makes it possible to reduce the pressure drops in the tubes, in particular because the hairpin curvature of the tube located at the point of curvature towards the outside is less than the curvature of the tube located at this point towards the interior.
  • the invention also applies to inductors of different configuration, in particular in the shape of a "U".

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • General Induction Heating (AREA)
  • Burglar Alarm Systems (AREA)
  • Details Of Aerials (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Thermistors And Varistors (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Water Treatment By Electricity Or Magnetism (AREA)
  • Magnetic Treatment Devices (AREA)

Abstract

Le dispositif de protection des pôles d'un inducteur électromagnétique comprend un échangeur thermique formé par un ou plusieurs tubes métalliques (6) disposés dans un même plan et agencés pour y permettre la circulation d'un fluide de refroidissement, et selon une disposition telle qu'il y ait au plus une jonction électrique entre deux tubes ou éléments de tubes quelconques.L'échangeur est fixé sur une plaque support rigide (5) électriquement isolante, enrobé de béton réfractaire (10) et recouvre l'ensemble de la surface polaire jusqu'aux capotages (3).L'échangeur peut être conformé selon une succession d'épingles à cheveux alternées, ou selon une spirale à une ou plusieurs branches.Le dispositif sert notamment à la protection des pôles d'inducteurs utilisés pour le chauffage par induction de produits métalliques.The device for protecting the poles of an electromagnetic inductor comprises a heat exchanger formed by one or more metal tubes (6) arranged in the same plane and arranged to allow the circulation of a cooling fluid therein, and according to an arrangement such as '' there is at most one electrical junction between any two tubes or tube elements The exchanger is fixed on a rigid support plate (5) electrically insulating, coated with refractory concrete (10) and covers the entire polar surface up to the cowls (3). The exchanger can be shaped according to a succession of alternating hairpins, or according to a spiral with one or more branches. The device is used in particular to protect the poles of inductors used for heating by induction of metal products.

Description

La présente invention concerne un dispositif de protec­tion des pôles d'inducteurs, notamment utilisés pour le chauffage ou le réchauffage de produits métalliques par induction.The present invention relates to a device for protecting the poles of inductors, in particular used for heating or reheating metallic products by induction.

Il est connu d'utiliser à cette fin des inducteurs élec­tromagnétiques à champ traversant. De tels inducteurs sont notam­ment décrits dans le document FR 2583249. D'une manière générale, ils comportent une culasse magnétique en forme de C, les extrémi­tés du C formant les deux pôles de l'inducteur, portant les bobines d'induction, étant placés de part et d'autre du produit à réchauffer.It is known to use for this purpose electromagnetic inductors with traversing field. Such inductors are described in particular in document FR 2583249. In general, they comprise a C- shaped magnetic yoke, the ends of the C forming the two poles of the inductor, carrying the induction coils, being placed on either side of the product to be reheated.

Pour conserver un bon rendement, les pôles doivent être le plus proche possible du produit. Ceci fait que les pôles et les bobines d'induction qu'ils portent se trouvent soumis au fort rayonnement thermique du produit chaud. De plus, dans des conditions d'exploitation industrielle, par exemple lors du réchauffage des rives de brames ou produits laminés, les inducteurs et surtout leurs pôles sont soumis à des agressions chimiques et mécaniques, par exemple arrosage important, dépôt de calamine, risque de choc avec le produit réchauffé.To maintain good performance, the poles must be as close as possible to the product. This causes the poles and the induction coils which they carry to be subjected to the strong thermal radiation of the hot product. In addition, under industrial operating conditions, for example during reheating of the edges of slabs or laminated products, the inductors and especially their poles are subjected to chemical and mechanical attack, for example heavy watering, scale deposit, risk of shock with the heated product.

On connait un dispositif de protection des pôles consis­tant en une plaque en réfractaire poreux placée sur la face du pôle en regard du produit, ce réfractaire étant refroidi par circulation interne d'air. Ces dispositifs constituent une bonne protection thermique, mais présentent toutefois l'inconvé­nient de s'oxyder et de se colmater facilement, et d'être atta­qués par la calamine provenant du produit réchauffé. Il en résulte la nécessité de remplacer ce réfractaire poreux assez fréquemment, ce qui nécessite l'arrêt de l'installation, entraînant des coûts d'exploitation qui s'ajoutent au coût élevé dudit réfractaire.There is a known device for protecting the poles consisting of a porous refractory plate placed on the face of the pole opposite the product, this refractory being cooled by internal circulation of air. These devices constitute good thermal protection, but have the disadvantage of oxidizing and clogging easily, and of being attacked by the scale coming from the heated product. This results in the need to replace this porous refractory quite frequently, which requires stopping the installation, resulting in operating costs which are added to the high cost of said refractory.

Le but de la présente invention est d'assurer la protec­tion des pôles d'inducteurs soumis à des contraintes tant thermi­ques que mécaniques et chimiques, de manière fiable et durable, sans entraîner de perte de rendement du réchauffage.The object of the present invention is to ensure the protection of the poles of inductors subjected to thermal, mechanical and chemical stresses, in a reliable and durable manner, without causing loss of heating efficiency.

Un autre but est de résoudre les divers problèmes évo­qués ci-dessus.Another aim is to solve the various problems mentioned above.

Avec ces objectifs en vue, la présente invention a pour objet un dispositif de protection, notamment thermique, des pôles d'un inducteur électromagnétique.With these objectives in view, the present invention has for object a device for protecting, in particular thermal, the poles of an electromagnetic inductor.

Conformément à l'invention, ce dispositif comporte un échangeur thermique formé par un ou plusieurs tubes métal­liques amagnétiques sensiblement coplanaires agencés pour y permettre la circulation d'un fluide de refroidissement et selon une disposition telle qu'il y ait au plus une seule jonction électrique entre deux tubes ou éléments de tubes quelconques,de façon à limiter les bouclages électriques entre tubes ou portions de tubes voisins ou non.According to the invention, this device comprises a heat exchanger formed by one or more non-magnetic metal tubes substantially coplanar arranged to allow the circulation of a cooling fluid and in an arrangement such that there is at most a single electrical junction between any two tubes or tube elements, so as to limit the electrical loopbacks between tubes or portions of neighboring tubes or not.

Il est précisé que le terme jonction électrique concerne ici le contact direct ou des liaisons de faible résistance, à l'exclusion de liaisons de résistance élevée existant dans des matériaux qui ne sont pas des isolants parfaits.It is specified that the term electrical junction here relates to direct contact or low resistance connections, to the exclusion of high resistance connections existing in materials which are not perfect insulators.

Selon une disposition particulière de l'invention, l'é­changeur est conformé selon une succession d'épingles à cheveux alternativement inversées.According to a particular arrangement of the invention, the exchanger is shaped according to a succession of alternately inverted hairpins.

Selon une autre disposition, l'échangeur est conformé en spirale à une branche ou plus.According to another arrangement, the exchanger is shaped in a spiral to one branch or more.

Selon une autre disposition particulière, l'échangeur est soutenu et fixé sur une plaque rigide électriquement isolante, et enrobé de béton réfractaire, l'ensemble formant un panneau composite de faible épaisseur, de dimensions suffisantes pour couvrir la face polaire de chaque pôle.According to another particular arrangement, the exchanger is supported and fixed on a rigid electrically insulating plate, and coated with refractory concrete, the assembly forming a composite panel of small thickness, of dimensions sufficient to cover the pole face of each pole.

Le dispositif selon l'invention permet en fait de conci­lier deux fonctions d'incidences divergentes : d'une part, la protection thermique du pôle par refroidissement forcé au moyen d'un échangeur à tubes métalliques, d'autre part, la conserva­tion d'un bon rendement de chauffage de l'inducteur.The device according to the invention makes it possible in fact to reconcile two divergent incidence functions: on the one hand, the thermal protection of the pole by forced cooling by means of a metal tube exchanger, on the other hand, the conservation of good heating efficiency of the inductor.

En effet, un ensemble de tubes métalliques interposés entre pôle et produit, forme généralement un écran qui s'oppose au passage du flux magnétique et dans lequel peuvent être engen­drés des courants électriques de forte intensité qui ont pour effets de s'opposer au passage du flux et d'échauffer le circuit où ils se créent.Indeed, a set of metal tubes interposed between pole and product, generally forms a screen which opposes the passage of magnetic flux and in which can be generated high intensity electric currents which have the effect of opposing the passage of flow and heat up the circuit where they are created.

La disposition des tubes conforme à l'invention permet d'éviter ces effets et d'assurer une "transparence" maximale du champ magnétique intense créé par l'inducteur.The arrangement of the tubes according to the invention makes it possible to avoid these effects and to ensure maximum "transparency" of the intense magnetic field created by the inductor.

L'invention a aussi pour objet un inducteur pourvu du dispositif de protection des pôles tel que décrit ci-dessus, qui sera alors avantageusement dimensionné et placé en regard de chacune des faces polaires dont il épouse la forme de façon à recouvrir celles-ci ainsi que les bobines d'induction et les isolants et capotages, de manière à réaliser une bonne étanchéité de l'ensemble du pôle et de ses circuits.The invention also relates to an inductor provided with the pole protection device as described above, which will then advantageously be dimensioned and placed opposite each of the pole faces of which it follows the shape so as to cover them as well. as the induction coils and the insulators and cowlings, so as to achieve good sealing of the entire pole and its circuits.

D'autres caractéristiques et avantages apparaîtront à la lecture de la description qui va être faite à titre d'exem­ple, d'un dispositif conforme à l'invention.Other characteristics and advantages will appear on reading the description which will be given by way of example, of a device according to the invention.

On se reportera aux dessins annexés dans lesquels :

  • - la figure 1 est une vue simplifiée d'un pôle d'induc­teur pourvu de son dispositif de protection et montrant celui-ci en coupe ;
  • - la figure 2 est un schéma du circuit de l'échangeur dans sa configuration en "épingle" ;
  • - les figures 3 et 4 sont deux schémas du circuit de l'échangeur dans la configuration en spirale.
  • - la figure 5 est une vue de détail partielle d'une vari­ante utilisant des blocs réfractaires au lieu d'un enrobage de béton monobloc.
Reference is made to the accompanying drawings in which:
  • - Figure 1 is a simplified view of an inductor pole provided with its protection device and showing it in section;
  • - Figure 2 is a diagram of the exchanger circuit in its "pin"configuration;
  • - Figures 3 and 4 are two diagrams of the exchanger circuit in the spiral configuration.
  • - Figure 5 is a partial detail view of a variant using refractory blocks instead of a one-piece concrete coating.

A la figure 1 est représenté un pôle d'un inducteur du type en C à culasse articulée,tel que décrit dans le document FR 2583249 auquel on pourra se reporter pour plus de détails sur la constitution générale de l'inducteur. Il est simplement rappelé ici que dans ce type d'inducteur, destiné notamment au réchauffage des rives d'ébauches de produits métalliques généralement plats, un deuxième pôle, similaire à celui repré­senté figure 1, est disposé en regard de celui-ci, les deux pôles formant les extrémités d'une culasse magnétique en forme de "C" qui les relie. Le champ magnétique intense créé par l'inducteur a pour effet de réchauffer le produit qui passe entre les deux pôles en regard. Les puissances induites sont de l'ordre de plusieurs centaines de KW, ce qui, ramené à la surface de la culasse, correspond à des puissances qui peuvent dépasser 5 MW/m².In Figure 1 is shown a pole of a C- type inductor with hinged yoke, as described in document FR 2583249 to which reference may be made for more details on the general construction of the inductor. It is simply recalled here that in this type of inductor, intended in particular for reheating the edges of blanks of generally flat metal products, a second pole, similar to that shown in FIG. 1, is arranged opposite this, both poles forming the ends of a "C" shaped magnetic yoke which connects them. The intense magnetic field created by the inductor has the effect of heating the product which passes between the two facing poles. The induced powers are of the order of several hundred KW, which, brought to the surface of the cylinder head, corresponds to powers which can exceed 5 MW / m².

Le pôle de la figure 1 comporte une bobine d'induction 2 entourant l'extrémité de la culasse magnétique 1. Un capotage de protection 3 entoure l'ensemble de l'extrémité polaire (cu­lasse et bobine), un écran thermique pouvant être interposé entre la bobine 2 et le capotage 3.The pole of Figure 1 has an induction coil 2 surrounding the end of the magnetic yoke 1. A protective cover 3 surrounds the entire polar end (yoke and coil), a heat shield can be interposed between coil 2 and cover 3.

La plaque composite 4 formant le dispositif de protection conforme à l'invention est formée d'une plaque support 5 en matériau non métallique rigide, électriquement isolant, tel qu'un matériau à base de fibre de verre, par exemple en "silli­rite 64120", de quelques millimètres d'épaisseur.The composite plate 4 forming the protection device according to the invention is formed of a support plate 5 of rigid non-metallic material, electrically insulating, such as a material based on glass fiber, for example in "sillirite 64120" , a few millimeters thick.

Un échangeur en tube inox 6 enrobé de résine époxyde est fixé sur la plaque support 5. Cet échangeur a une configura­tion en "épingles à cheveux" successives alternées ainsi que réprésenté à la figure 2. La fixation de l'échangeur 6 sur la plaque support 5 est assurée par des vis 7 placées au creux de chacune des "épingles" du circuit, ainsi qu'indiqué schémati­quement sur la figure 2. Cette disposition est essentiellement destinée à éviter le bouclage électrique entre deux épingles adjacentes qui se produirait si des pièces conductrices étaient en contact simultané avec deux épingles, successives ou non, à un autre endroit que celui indiqué.An exchanger in stainless steel tube 6 coated with epoxy resin is fixed on the support plate 5. This exchanger has a configuration in successive alternating "hairpins" as shown in FIG. 2. The attachment of the exchanger 6 on the support plate 5 is ensured by screws 7 placed in the hollow of each of the "pins" of the circuit, as indicated diagrammatically in FIG. 2. This arrangement is essentially intended to avoid electrical looping between two adjacent pins which would occur if conductive parts were in simultaneous contact with two pins, successive or not, in a location other than that indicated.

L'écrou 8 de la vis 7 est placé dans un lamage réalisé dans la plaque support 5, de manière à ne pas dépasser de la surface de celle-ci. Une feuille 9 en matériau isolant est collée sous la plaque 5,dissimulant les écrous 8 et garantissant ainsi l'isolement électrique entre les vis de fixa­tion 7.The nut 8 of the screw 7 is placed in a counterbore made in the support plate 5, so as not to protrude from the surface thereof. A sheet 9 of insulating material is glued under the plate 5, concealing the nuts 8 and thus guaranteeing the electrical isolation between the fixing screws 7.

Les tubes 6 de l'échangeur sont enrobés dans un béton réfractaire 10, (par exemple le béton à base de carbure de silicium commercialisé sous le nom de "morgan montex CIM 02"). Ce béton recouvre totalement les tubes 6 et sa faible conductivité élec­trique permet de limiter d'éventuels courants de bouclage entre épingles voisines.The tubes 6 of the exchanger are coated in a refractory concrete 10 (for example the concrete based on silicon carbide marketed under the name of "morgan montex CIM 02"). This concrete completely covers the tubes 6 and its low electrical conductivity makes it possible to limit any looping currents between neighboring pins.

Avantageusement, mais non nécessairement, ce béton est recouvert sur une face d'une plaque de matériau vitro-céramique 11, ou tout autre matériau similaire, qui présente une grande résistance à la chaleur et surtout aux chocs thermiques, alliée à une bonne résistance mécanique. On peut également utiliser à la place de cette plaque un tissu textile céramique, ou un revêtement isolant (type coating) à base d'alumine ou silice.Advantageously, but not necessarily, this concrete is covered on one side with a plate of ceramic-ceramic material 11, or any other similar material, which has great resistance to heat and especially to thermal shock, combined with good mechanical resistance. . It is also possible to use, instead of this plate, a ceramic textile fabric, or an insulating coating (type coating) based on alumina or silica.

La plaque composite 4 est fixée sur le pôle de l'inducteur par boulonnage, soit directement sur la culasse, soit sur des supports annexes disposés entre bobine et capotages.The composite plate 4 is fixed to the pole of the inductor by bolting, either directly on the cylinder head, or on additional supports arranged between coil and cowlings.

Quels que soient les moyens de fixation, ceux-ci sont isolés électriquement des tubes 6 de l'échangeur.Whatever the fixing means, these are electrically isolated from the tubes 6 of the exchanger.

L'épaisseur de la plaque 4 est d'environ 15 mm et ses dimensions et sa forme sont déterminées de manière a couvrir l'ensemble du pôle, jusqu'au capotage 3, un couvre-joint 12 étant disposé autour de la plaque 4 pour empêcher des infiltra­tions d'eau ou la pénétration de poussières ou autres corps solides à l'intérieur du capotage 3.The thickness of the plate 4 is approximately 15 mm and its dimensions and shape are determined so as to cover the entire pole, up to the casing 3, a joint cover 12 being arranged around the plate 4 to prevent water infiltration or the ingress of dust or other solid bodies inside the enclosure 3.

La figure 2 représente schématiquement une disposition préférentielle des tubes de l'echangeur. Celui-ci est ici réalisé en trois circuits indépendants, ce qui permet par exemple d'adap­ter l'intensité du refroidissement selon les zones couvertes par réglage du débit du fluide de refroidissement, couramment de l'eau. Cette disposition en "épingles" permet de couvrir au mieux la surface du pôle, car il est aisé d'adapter le nombre et la longueur des épingles en fonction de la forme de la surface à couvrir.FIG. 2 schematically represents a preferred arrangement of the tubes of the exchanger. This is here carried out in three independent circuits, which allows for example to adapt the intensity of cooling according to the areas covered by adjusting the flow rate of the cooling fluid, usually water. This arrangement in "pins" makes it possible to cover the surface of the pole as well as possible, because it is easy to adapt the number and the length of the pins according to the shape of the surface to be covered.

En variantes, l'échangeur peut avoir une configuration en spirale telle que représentée aux figures 3 et 4.Alternatively, the exchanger can have a spiral configuration as shown in Figures 3 and 4.

La figure 4 montre schématiquement une disposition en double spirale inversée avec un tube unique ; l'alimentation et le retour de fluide de refroidissement sont indiqués par les flèches A et R.Figure 4 schematically shows a double inverted spiral arrangement with a single tube; the cooling fluid supply and return are indicated by the arrows A and R.

La disposition de la figure 3 montre quatre spirales alimentées par une alimentation centrale. Dans ce cas, l'alimen­tation se fait par une tuyauterie dans l'axe du pôle, à travers la culasse 1.The arrangement in Figure 3 shows four spirals powered by a central power supply. In this case, the supply is made by a pipe in the axis of the pole, through the cylinder head 1.

Une alimentation centrale peut également être réalisée dans le cas des dispositions des figures 2 et 4, et présente l'avantage de participer au refroidissement de la culasse magne­tique.A central supply can also be carried out in the case of the arrangements in FIGS. 2 and 4, and has the advantage of participating in the cooling of the magnetic yoke.

Une caractéristique essentielle de ces échangeurs est que deux tubes ou éléments de tube se joignent au maximum en un point, de manière à éviter tout bouclage électrique dans l'échangeur.An essential characteristic of these exchangers is that two tubes or tube elements join at most at one point, so as to avoid any electrical looping in the exchanger.

Les tubes sont de préférence en acier inoxydable amagnétique et par simplicité, de section circulaire. Il est possible, notamment pour réduire l'épaisseur de la plaque composite de protection 4, d'utiliser des tubes de section aplatie, ou même éventuellement de section prati­quement rectangulaire.The tubes are preferably made of non-magnetic stainless steel and for simplicity, of circular section. It is possible, in particular to reduce the thickness of the composite protection plate 4, to use tubes of flattened section, or even possibly of practically rectangular section.

On choisira des tubes d'épaisseur réduite, toujours dans le but de réduire les éventuels courants électrique engendrés par le champ magnétique, par augmentation de la résistance électrique desdits tubes. Les tubes pouvant par ailleurs, au lieu d'être enrobés de résine époxyde, ainsi qu'indiqué précédemment, être revêtus d'un film isolant ou enrobés d'une autre résine isolante (polyester par exemple).Tubes of reduced thickness will be chosen, always with the aim of reducing any electrical currents generated by the magnetic field, by increasing the electrical resistance of said tubes. The tubes which can moreover, instead of being coated with epoxy resin, as indicated above, be coated with an insulating film or coated with another insulating resin (polyester for example).

Le rôle du dispositif de protection étant essentiellement de former un écran thermique protégeant le pôle et ses accessoires du rayonnement du produit réchauffé, on recherchera à rapprocher au maximum les tubes les uns des autres. De plus, et plus particuliè­rement dans le cas du dispositif comportant la plaque de matériau vitrocéramique 11, l'utilisation d'un béton présentant une conducti­bilité thermique assez bonne permet une diffusion dans sa masse de la chaleur reçue par sa surface et de ce fait permet d'obtenir un refroidissement de la dite plaque vitrocéramique, qui peut ainsi être maintenue à une température voisine de 700°C par exemple, alors que le produit réchauffé est à plus de 1000°C.The role of the protection device being essentially to form a heat shield protecting the pole and its accessories from the radiation of the heated product, we will seek to bring the tubes as close as possible to each other. In addition, and more particularly in the case of the device comprising the plate of glass-ceramic material 11, the use of a concrete having a fairly good thermal conductivity allows a diffusion in its mass of the heat received by its surface and therefore allows to obtain a cooling of said ceramic glass plate, which can thus be maintained at a temperature close to 700 ° C. for example, while the heated product is at more than 1000 ° C.

On pourra aussi, dans la mesure ou les caractéristiques mécaniques du béton utilisé le permettent ne pas utiliser de plaque support.We can also, insofar as the mechanical characteristics of the concrete used allow it not to use a support plate.

Dans une autre variante, notamment dans le cas de l'échan­geur en "épingles", au lieu de noyer les tubes 6 dans le béton réfrac­taire 10, on pourra remplacer celui-ci par une pluralité de blocs 13 en matériau isolant de caractéristiques similaires (béton réfrac­taire, céramique, quartz, etc...) de manière à reconstituer l'ensemble de l'enrobage de béton 10.In another variant, in particular in the case of the "pin" exchanger, instead of drowning the tubes 6 in the refractory concrete 10, it may be replaced by a plurality of blocks 13 made of insulating material with similar characteristics ( refractory concrete, ceramic, quartz, etc.) so as to reconstitute the entire concrete coating 10.

Ces blocs ont une largeur égale à l'entraxe entre deux tubes 6 voisins et ils comportent sur leurs deux côtés longitudinaux des concavités 14 épousant la section des tubes de manière à pouvoir être insérés entre ceux-ci pour reconstituer globalement l'enrobage de béton 10. On déposera de préférence plusieurs de ces blocs adja­cents dans un même espace entre tubes. Cette disposition en blocs séparés autorise des dilatations différentielles entre différentes zones du dispositif sans les risques de fissuration existant dans le cas du béton monobloc 10. Afin de recouvrir les zones courbes des épingles, le premier bloc 13′ de chaque rangée comporte un prolongement 15 de sa partie supérieure plane.These blocks have a width equal to the distance between two neighboring tubes 6 and they have on their two longitudinal sides concavities 14 matching the section of the tubes so as to be able to be inserted between them to reconstitute the concrete coating overall. Preferably, several of these adjacent blocks will be placed in the same space between tubes. This arrangement in separate blocks allows differential expansions between different areas of the device without the risk of cracking existing in the case of monobloc concrete 10. In order to cover the curved areas of the pins, the first block 13 ′ of each row has an extension 15 of its flat upper part.

L'invention n'est pas limitée au dispositif et à ses variantes décrits ci-dessus uniquement à titre d'exemple. En particulier dans le cadre de la disposition des tubes en "épingles à cheveux", il peut être prévu de disposer, dans la même zone, deux ou plusieurs tubes ayant cette configuration, mais disposés en parallèle, chaque épingle d'un tube étant imbriquée dans une épingle formée par l'autre tube, et ceci alternativement, toutes les épingles restant bien sûr coplanaires.The invention is not limited to the device and to its variants described above only by way of example. In particular in the context of the arrangement of tubes in "hairpins", provision may be made to have, in the same area, two or more tubes having this configuration, but arranged in parallel, each pin of a tube being nested in a pin formed by the other tube, and this alternately, all the pins of course remaining coplanar.

Cette disposition permet de réduire les pertes de charge dans les tubes, notamment du fait que la courbure en épingle du tube situé, au point de courbure, vers l'extérieur, est plus faible que la courbure du tube situé en ce point vers l'intérieur.This arrangement makes it possible to reduce the pressure drops in the tubes, in particular because the hairpin curvature of the tube located at the point of curvature towards the outside is less than the curvature of the tube located at this point towards the interior.

Il peut également être prévu de disposer un tube supplémentaire entourant l'ensemble des tubes disposés en épingle à cheveux, ceci afin d'homogénéiser le refroidissement dans la zone proche des extrémités des épingles, et/ou d'éviter un échauffement des cornières formant le couvre-joint 12.It can also be provided to have an additional tube surrounding all of the tubes arranged in a hairpin, this in order to homogenize the cooling in the area near the ends of the pins, and / or to avoid overheating of the angles forming the joint cover 12.

L'invention s'applique aussi à des inducteurs de configuration différente, notamment en forme de "U".The invention also applies to inductors of different configuration, in particular in the shape of a "U".

Claims (14)

1) Dispositif de protection des pôles d'un inducteur électromagnétique, caractérisé en ce qu'il comporte un échangeur thermique formé par un ou plusieurs tubes métalliques (6) amagné­tiques disposés dans un même plan ou sensiblement dans un même plan et agencés pour y permettre la circulation d'un fluide de refroidissement et selon une disposition telle qu'il y ait au plus une seule jonction électrique entre deux tubes ou éléments de tubes quelconques.1) Device for protecting the poles of an electromagnetic inductor, characterized in that it comprises a heat exchanger formed by one or more non-magnetic metal tubes (6) arranged in the same plane or substantially in the same plane and arranged to allow it the circulation of a cooling fluid and according to an arrangement such that there is at most a single electrical junction between any two tubes or tube elements. 2) Dispositif selon la revendication 1, caractérisé en ce que l'échangeur (6′) est conformé selon une succession d' "épingles à cheveux" alternativement inversées.2) Device according to claim 1, characterized in that the exchanger (6 ′) is shaped according to a succession of alternately inverted "hairpins". 3) Dispositif selon la revendication 1, caractérisé en ce que l'échangeur (6˝,6′˝) est conformé en spirale à une branche ou plus.3) Device according to claim 1, characterized in that the exchanger (6˝, 6′˝) is spirally shaped to one branch or more. 4) Dispositif selon la revendication 1, caractérisé en ce que l'échangeur (6′, 6˝, 6′˝) est totalement enrobé dans un béton réfractaire (10).4) Device according to claim 1, characterized in that the exchanger (6 ′, 6˝, 6′˝) is completely embedded in a refractory concrete (10). 5) Dispositif selon la revendication 1, caractérisé en ce que des blocs (13) en matériaux réfractaires électriquement isolant sont insérés entre deux tubes voisins (6), ces blocs étant conformés de manières à épouser la forme des tubes et à recouvrir globalement l'ensemble de l'échangeur.5) Device according to claim 1, characterized in that blocks (13) of electrically insulating refractory materials are inserted between two neighboring tubes (6), these blocks being shaped so as to match the shape of the tubes and to cover the whole set of the exchanger. 6) Dispositif selon la revendication 1, caractérisé en ce que l'échangeur (6′ ,6˝, 6′˝) est fixé sur une plaque support rigide (5) électriquement isolante, et enrobé de béton réfractaire (10), l'ensemble formant un panneau composite (4) de faible épaisseur et de dimensions suffisantes pour couvrir la face polaire du pôle.6) Device according to claim 1, characterized in that the exchanger (6 ′, 6˝, 6′˝) is fixed on a rigid support plate (5) electrically insulating, and coated with refractory concrete (10), assembly forming a composite panel (4) of small thickness and of dimensions sufficient to cover the pole face of the pole. 7) Dispositif selon l'une des revendications 4 à 6, carac­térisé en ce qu'il comporte une plaque en matériau vitro-céramique ou similaire (11) recouvrant une face du béton réfractaire (10) du pan­neau (4).7) Device according to one of claims 4 to 6, characterized in that it comprises a plate of ceramic-ceramic material or the like (11) covering one face of the refractory concrete (10) of the panel (4). 8) Dispositif selon l'une des revendications 4 à 6, caracté­risé en ce que les tubes (6) sont en acier inoxydable amagnétique.8) Device according to one of claims 4 to 6, characterized in that the tubes (6) are made of non-magnetic stainless steel. 9) Dispositif selon la revendication 16, caractérisé en ce que les moyens de fixation des tubes (6) sur la plaque support (5) sont électriquement isolés entre eux.9) Device according to claim 16, characterized in that the means for fixing the tubes (6) on the support plate (5) are electrically isolated from each other. 10) Dispositif selon la revendication 1, caractérisé en ce que l'échangeur (6′, 6˝,6′˝) comporte une alimentation centrale.10) Device according to claim 1, characterized in that the exchanger (6 ′, 6˝, 6′˝) comprises a central supply. 11) Inducteur électromagnétique pour le réchauffage de produits métalliques par induction par champ magnétique traversant du type comportant une culasse en forme de "C" ou de "U" caractérisé en ce que chacun des pôles de l'inducteur est pourvu du dispositif selon l'une des revendications 1 à 10, placé en regard de la face polaire dont il épouse la forme.11) Electromagnetic inductor for heating metallic products by induction through a magnetic field of the type comprising a cylinder head in the shape of a "C" or "U" characterized in that each of the poles of the inductor is provided with the device according to the one of claims 1 to 10, placed opposite the polar face of which it follows the shape. 12) Inducteur selon la revendication 11, caractérisé en ce que le dispositif de protection couvre toute la surface du pôle de manière étanche.12) Inductor according to claim 11, characterized in that the protection device covers the entire surface of the pole in a sealed manner. 13) Inducteur selon la revendication 11, caractérisé en ce que des moyens de fixation du dispositif de protection sur le pôle de l'inducteur sont prévus qui sont électriquement isolés.13) Inductor according to claim 11, characterized in that means for fixing the protection device on the pole of the inductor are provided which are electrically isolated. 14) Inducteur selon la revendication 11, caractérisé en ce qu'il comporte un passage axial réservé dans l'extrémité de la culasse pour l'alimentation de l'échangeur.14) Inductor according to claim 11, characterized in that it comprises an axial passage reserved in the end of the cylinder head for the supply of the exchanger.
EP89400908A 1988-04-26 1989-04-03 Protecting device for induction poles and inductor provided with this device Expired - Lifetime EP0340057B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8805940A FR2630612B1 (en) 1988-04-26 1988-04-26 DEVICE FOR PROTECTING INDUCER POLES AND INDUCER PROVIDED WITH SUCH DEVICE
FR8805940 1988-04-26

Publications (2)

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EP0340057A1 true EP0340057A1 (en) 1989-11-02
EP0340057B1 EP0340057B1 (en) 1994-12-07

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EP89400908A Expired - Lifetime EP0340057B1 (en) 1988-04-26 1989-04-03 Protecting device for induction poles and inductor provided with this device

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US (1) US4960967A (en)
EP (1) EP0340057B1 (en)
JP (1) JP2807734B2 (en)
KR (1) KR0142908B1 (en)
AT (1) ATE115354T1 (en)
AU (1) AU615283B2 (en)
BR (1) BR8901951A (en)
CA (1) CA1313236C (en)
DE (1) DE68919743T2 (en)
ES (1) ES2065403T3 (en)
FR (1) FR2630612B1 (en)
GR (1) GR3015004T3 (en)
ZA (1) ZA893056B (en)

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EP0576351A1 (en) * 1992-06-24 1993-12-29 Société CELES Protecting and cooling arrangement for the poles of an electromagnetic inductor

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DE3934208C2 (en) * 1989-10-13 1994-02-17 Kuesters Eduard Maschf Coil formers for the inductive heating of rolls
FR2663490B1 (en) * 1990-06-15 1992-09-11 Rotelec Sa INDUCTIVE HEATING COIL.
US5101086A (en) * 1990-10-25 1992-03-31 Hydro-Quebec Electromagnetic inductor with ferrite core for heating electrically conducting material
US6259347B1 (en) * 1997-09-30 2001-07-10 The United States Of America As Represented By The Secretary Of The Navy Electrical power cooling technique
FR2821925B1 (en) * 2001-03-06 2003-05-16 Celes THERMAL INSULATION GAS AND VACUUM ENCLOSURE FOR AN INDUCTION HEATING DEVICE
ATE374514T1 (en) * 2004-04-30 2007-10-15 Sgl Carbon Ag WORKPIECE CARRIER FOR INDUCTIVE HEATING OF WORKPIECES
CH698904A2 (en) * 2008-05-27 2009-11-30 Alexander Stoev Water-cooled reactor.

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DE1158194B (en) * 1962-06-22 1963-11-28 Zd Y Elektrotepelnych Zarizeni Inductor arrangement for inductive heating of continuous metal strips
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FR2693073A1 (en) * 1992-06-24 1993-12-31 Celes Device for protecting and cooling the poles of an electromagnetic inductor.
US5485483A (en) * 1992-06-24 1996-01-16 Celes Device for protecting and cooling the poles of an electromagnetic inductor

Also Published As

Publication number Publication date
KR0142908B1 (en) 1998-10-01
ZA893056B (en) 1989-12-27
JPH01313882A (en) 1989-12-19
US4960967A (en) 1990-10-02
ATE115354T1 (en) 1994-12-15
EP0340057B1 (en) 1994-12-07
KR890016872A (en) 1989-11-30
CA1313236C (en) 1993-01-26
AU615283B2 (en) 1991-09-26
JP2807734B2 (en) 1998-10-08
ES2065403T3 (en) 1995-02-16
FR2630612B1 (en) 1996-05-24
AU3272389A (en) 1989-11-02
DE68919743D1 (en) 1995-01-19
DE68919743T2 (en) 1995-04-27
FR2630612A1 (en) 1989-10-27
BR8901951A (en) 1989-12-05
GR3015004T3 (en) 1995-05-31

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