EP0129160A2 - Durchlaufwärmeanlage für metallische Produkte mittels Induktion - Google Patents

Durchlaufwärmeanlage für metallische Produkte mittels Induktion Download PDF

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Publication number
EP0129160A2
EP0129160A2 EP84106525A EP84106525A EP0129160A2 EP 0129160 A2 EP0129160 A2 EP 0129160A2 EP 84106525 A EP84106525 A EP 84106525A EP 84106525 A EP84106525 A EP 84106525A EP 0129160 A2 EP0129160 A2 EP 0129160A2
Authority
EP
European Patent Office
Prior art keywords
magnetic
product
heated
roller
stack
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
EP84106525A
Other languages
English (en)
French (fr)
Other versions
EP0129160A3 (en
EP0129160B1 (de
Inventor
Bernard Chausse
Jean Hellegouarc'h
Jean Maurice
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alstom SA
Original Assignee
Compagnie Electro Mecanique SA
Alstom SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Compagnie Electro Mecanique SA, Alstom SA filed Critical Compagnie Electro Mecanique SA
Publication of EP0129160A2 publication Critical patent/EP0129160A2/de
Publication of EP0129160A3 publication Critical patent/EP0129160A3/fr
Application granted granted Critical
Publication of EP0129160B1 publication Critical patent/EP0129160B1/de
Expired legal-status Critical Current

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Classifications

    • 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
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/101—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces
    • H05B6/103—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces multiple metal pieces successively being moved close to the inductor
    • H05B6/104—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces multiple metal pieces successively being moved close to the inductor metal pieces being elongated like wires or bands

Definitions

  • the invention relates to a device for heating metal products by induction scrolling.
  • a first known device comprises these elements and is described in American patent US-A-3008 026 (Kennedy).
  • said magnetic stack of each transport roller is constituted by thick removable disks which can have various values of their magnetic permeabilities to allow obtaining a suitable distribution of the magenetic heating flux according to the width of the product to be heated.
  • the transport rollers are arranged in pairs above and below the product to be heated and the magnetic discs are contact with this product.
  • the inductor coils surround the transport rollers above and below the product to be heated to ensure a symmetrical distribution of the flow. These rollers are in contact with the latter to prevent any vertical displacement of this product, this latter under the action of magnetic forces created by the heating flow.
  • this first known device is intended exclusively for heating a thin strip at a low temperature, probably always less than 500 ° C., even when this patent mentions heat treatment and forming among the possible applications of this. device.
  • the heating power indeed appears low due to the arrangement of the coils and the fact that a high flux would raise the temperature of the magnetic discs above their Curie point, which would make them lose their magnetic permeability.
  • Such a flow would also directly heat the shafts constituting the stiffening elements of these rollers, since such shafts are normally made of a steel having a substantial magnetic permeability and would therefore be traversed by this flow. The heating of these trees would make them lose part of their mechanical qualities.
  • the present invention applies to the case where thick metallic products have to be heated or reheated to a high temperature, suitable for example to facilitate their subsequent deformation. It applies more particularly to the case where these products are long steel products, for example flat steel products which are still hot during rolling and which must be reheated to a temperature of the order of 1000 to 1200 ° C. to allow continue the rolling process under good conditions.
  • the thickness of such a product can for example be between 25 and 250 mm approximately, and the power which must be dissipated to heat it between 10 and 200 W / cm 2 approximately and most often between 50 and 200 W / em 2 .
  • the heating of such a product can be obtained by a flow passing through the smallest dimension or thickness of the flat product.
  • this flux can be obtained by a periodic variation - for example sinusoidal - of an inductive current in fixed coils. It can also be obtained by the longitudinal or transverse displacement of the waves of a sliding field generated by a fixed polyphase inductor. It can also result from the periodic variation of reluctance of a magnetic circuit excited in direct current, or of the mechanical displacement of poles excited in direct current.
  • the present invention aims to allow high temperature heating of metal products at the parade with increased power, using a simple device, easy maintenance, without increasing size and consuming no energy electric power only at a moderate frequency, for example at the frequency of the general supply network, that is to say 50 or 60 Hz.
  • the sheets used to constitute the magnetic stack of the rollers are of the type which are conventionally used for laminated magnetic circuits and the thickness of which is usually 0.5 mm.
  • the device also comprises stationary intermediate support slabs arranged in the intervals between the successive transport rollers to limit the downward bending of a product to be heated which is long and not very rigid, and these intermediate slabs comprise ferromagnetic blocks constituted by stacking, in the transverse direction, of magnetic sheets perpendicular to this direction to complete with the transport rollers said magnetic circuit looped under the product to be heated.
  • each intermediate paving comprises separators of non-magnetic refractory steel distributed in said transverse direction and protruding above said ferromagnetic blocks to separate the product to be heated in order to thermally isolate it from these blocks.
  • the invention allows the nesting of the transport means and the heating means without the one in any way hindering the implementation of the other, which eliminates the above drawbacks.
  • recourse is had to rollers and possibly to intermediate slabs, the constitution of which is new, in particular with the use of laminating of magnetic sheets, and can be easily adapted to the particular operating conditions of a mechanical, magnetic and thermal.
  • This makes it possible to apply to the products to be heated induction flows which do not have any discontinuity in the direction of transfer of these products.
  • the invention thus allows the greatest possible linear powers and therefore provides great compactness to the heating members. It therefore facilitates economic insertion of heating devices in existing or future rolling installations in which the required heating powers can reach several tens of megawatts.
  • FIG. 1 A first preferred embodiment of the invention is illustrated in FIG. 1.
  • the product to be heated 1 is conveyed by rollers 2 and moves over intermediate slabs 3.
  • Laminated magnetic circuits 4 form a longitudinal succession. They carry, housed in notches, inductor windings 5 generating the heating flows. These are stationary pulsed, that is to say fixed in space and variable in time at any point of the product.
  • their winding is of the single-phase type distributed with nested heads and is supplied by terminals A and B in alternating current at industrial frequency (50 or 60 Hz).
  • the inductors are protected from the thermal radiation of the heated product by a screen E, made of ceramic fiber about 5 cm thick for example.
  • a screen E made of ceramic fiber about 5 cm thick for example.
  • the rollers 2 and the intermediate slabs 3 are designed to have a high magnetic permeability while being the seat of losses by eddy currents and limited magnetic hysteresis and while retaining the mechanical aptitudes necessary for transporting the products to be heated.
  • the rollers are produced by stacking on a rigid shaft 21, between two clamping flanges 22 and 23, of a series of separators made of refractory non-magnetic steel 24 and of laminated magnetic blocks 25.
  • These blocks each consist of a stack of circular flat sheets. The insulation between sheets is obtained by oxidation of their surface.
  • the stack of these blocks and these separators is clamped between the flanges 22 and 23 with tension of the shaft 21, which makes this stack participate in the overall rigidity of the roller.
  • Each separator 24 has a circular support edge 24A coaxial with the roller and located radially beyond these blocks to maintain a radial gap of thermal insulation 24B between these blocks and the product to be heated supported by this support edge.
  • the design of the rollers can be adapted to each operating case.
  • the separators 24 can be made of more ordinary steels, or even be eliminated, and the magnetic circuits isolated by varnishing.
  • This cooling can be obtained by watering booms. As shown in FIG.
  • the intermediate slabs are produced by stacking non-magnetic refractory steel separators 31 and laminated magnetic blocks 32, the whole assembled and stiffened by the mechanically welded elements 33, 34 and 35.
  • the series of rollers and intermediate slabs constitutes an almost continuous magnetic circuit.
  • the air gaps separating the rollers and slabs can indeed have a thickness of the order of a centimeter, which does not significantly increase the reluctance of the total magnetic circuit, while practically avoiding any risk of blockage of the rollers by disturbing elements such as only pieces of scale.
  • the purpose of this arrangement is that the main air gap (of the order of one or more decimeters) encountered by the flux of the inductor is that which is formed by the vertical thickness of the product, the air above it and the thermal protection of the inductor. It allows an easy channeling of the flows intended for heating and avoids, during the design of the inductors, having to be concerned with the presence of the rollers and slabs and their positions.
  • the pitch of the inductors is greater than that of the rollers, but it could obviously be less than or equal to it.
  • FIG. 1 represents an embodiment of inductors in modules of a pitch, or a pole, without this being a necessity but rather a convenience. It is always possible to make multipolar modules or all of the inductors in one block.
  • the magnetic circuit 4 has a longitudinal succession of polar teeth 4X extending vertically, ending downward facing the product to be heated, and connected by their vertices, the inductor coils 5 inducing in these teeth a flux vertical variable magnetic.
  • FIG. 8 shows, in a top view of the pavements, a graded embodiment of sheets 36 in the magnetic blocks of the pavements to provide between these blocks and the separators 31, a space through which the scale which forms on the heated product can evacuate or be evacuated by an external means. Other arrangements can of course allow this evacuation of scale.
  • the product to be heated is for example constituted by a steel plate emerging from rolling mill cylinders.
  • This dish is for example 40 mm thick, 1.6 m wide, and travels at a speed of 1 m / s. It reaches a temperature of 925 C and must be reheated to 1050 C, which requires dissipating within it a short distance a power of about 25 MW.
  • the rollers are liquid cooled. They have a diameter of 400 mm, and their pitch of longitudinal succession is 950 mm
  • the inductor comprises 10 elements which each induce a power of 2.5 MW, at 50 Hz. They each extend over a length of 1.25 m.
  • the sheets of all the magnetic elements have a thickness of 0.5 mm and are isolated by oxidation according to the usual methods.
  • the inductor leaves a free gap of 150 mm above the product to be heated. The bending of this product between rollers is not shown. It is limited to 20 mm by intermediate paving.
  • the heated product goes to other rolling mill rolls to be brought to a thickness of 10 mm.
  • pole coils 5B on cores supplied with alternating current. These coils are integrated with their magnetic circuits 4B in place of the corresponding elements of FIG. 1.
  • the magnetic inductor circuit 4C can carry a polyphase winding 5C, for example three-phase as shown partially in FIG. 12.
  • This winding creates a sliding field whose direction of movement A or B depends on the succession phases, this direction agreeing or being opposite with that C of the transport of the product to be heated.
  • This magnetic circuit and its winding are integrated in place of the corresponding elements of FIG. 1.
  • the winding can be performed with concentric heads instead of nested heads as shown in FIG. 12.
  • the excitation coils 5D are carried by a magnetic cylinder 6 not necessarily laminated driven in rotation, the rest of the magnetic circuit of the inductor being shown in 4D.
  • the excitation coils 5E are carried by poles 7 not necessarily laminated driven in rotation, the rest of the magnetic circuit of the inductor being shown in 4E.
  • the coils are supplied with direct current. This avoids the reactive energy call existing in the previous modes.
  • the variation of the heating flows with an appropriate frequency is obtained by the rotation in a cylindrical space formed in the magnetic circuit 4D or 4E with a very small air gap vis-à-vis the parts 6 or 7.
  • the moving parts 6 or 7 are shown bipolar, but may include several pairs of poles.
  • the pole coils 5F are supplied with direct current.
  • the variation in flux is obtained by a cyclic variation in the reluctance of the entire magnetic circuit. This variation is caused by the rotation of a magnetic piece 8, laminated in the same direction as the rest of the circuit, and whose shape causes a notable variation in the air gap in which it moves and which is formed in the magnetic circuit. 4F.
  • rollers, intermediate slabs and support for the roller bearings can be produced in different shapes or materials without departing from the scope of the invention.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Induction Heating (AREA)
EP84106525A 1983-06-13 1984-06-07 Durchlaufwärmeanlage für metallische Produkte mittels Induktion Expired EP0129160B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8309723 1983-06-13
FR8309723A FR2547402B1 (fr) 1983-06-13 1983-06-13 Dispositif de chauffage de produits metalliques au defile par induction

Publications (3)

Publication Number Publication Date
EP0129160A2 true EP0129160A2 (de) 1984-12-27
EP0129160A3 EP0129160A3 (en) 1985-05-02
EP0129160B1 EP0129160B1 (de) 1988-07-27

Family

ID=9289709

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84106525A Expired EP0129160B1 (de) 1983-06-13 1984-06-07 Durchlaufwärmeanlage für metallische Produkte mittels Induktion

Country Status (5)

Country Link
US (1) US4595813A (de)
EP (1) EP0129160B1 (de)
JP (1) JPS6010581A (de)
DE (1) DE3473110D1 (de)
FR (1) FR2547402B1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2601217A1 (fr) * 1986-07-04 1988-01-08 Siderurgie Fse Inst Rech Dispositif d'entrainement et de guidage d'un produit metallique en bande soumis a une modification de temperature
EP0438130A2 (de) * 1990-01-17 1991-07-24 Sumitomo Heavy Industries, Ltd Elektromagnetisches Induktionsheizgerät

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004507870A (ja) * 2000-08-29 2004-03-11 オットー　ユンカー　ゲゼルシャフト　ミット　ベシュレンクテル　ハフツング 金属帯板を誘導加熱する装置
JP2002210510A (ja) * 2001-01-15 2002-07-30 Mitsubishi Heavy Ind Ltd 圧延ロールの誘導加熱装置および誘導加熱方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3008026A (en) * 1959-08-27 1961-11-07 Ella D Kennedy Induction heating of metal strip
DE1182373B (de) * 1963-05-30 1964-11-26 Siemens Ag Querfeld-Induktionsofen
FR2306269A1 (fr) * 1975-04-03 1976-10-29 Uddeholms Ab Appareil pour le chauffage par induction en continu de bandes metalliques en mouvement, avec dispositif combine de chauffage et de guidage a un poste de traitement
FR2473244A1 (fr) * 1980-01-04 1981-07-10 Cem Comp Electro Mec Procede et dispositif de chauffage electrique par induction de produits metalliques, utilisant des champs magnetiques pulses
FR2495752A1 (fr) * 1980-12-10 1982-06-11 Siderurgie Fse Inst Rech Dispositif de chauffage electrique par induction de produits electroconducteurs solides

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3489875A (en) * 1966-10-27 1970-01-13 Ajax Magnethermic Corp Apparatus for induction heating of slabs
US3471673A (en) * 1968-02-19 1969-10-07 United States Steel Corp Apparatus for inductively heating a traveling metal slab
US3715556A (en) * 1970-10-05 1973-02-06 Park Ohio Industries Inc Slab heating method and apparatus
FR2445085A1 (fr) * 1978-12-22 1980-07-18 Courdille Rene Installation de chauffage par induction de produits metallurgiques plats

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3008026A (en) * 1959-08-27 1961-11-07 Ella D Kennedy Induction heating of metal strip
DE1182373B (de) * 1963-05-30 1964-11-26 Siemens Ag Querfeld-Induktionsofen
FR2306269A1 (fr) * 1975-04-03 1976-10-29 Uddeholms Ab Appareil pour le chauffage par induction en continu de bandes metalliques en mouvement, avec dispositif combine de chauffage et de guidage a un poste de traitement
FR2473244A1 (fr) * 1980-01-04 1981-07-10 Cem Comp Electro Mec Procede et dispositif de chauffage electrique par induction de produits metalliques, utilisant des champs magnetiques pulses
FR2495752A1 (fr) * 1980-12-10 1982-06-11 Siderurgie Fse Inst Rech Dispositif de chauffage electrique par induction de produits electroconducteurs solides

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2601217A1 (fr) * 1986-07-04 1988-01-08 Siderurgie Fse Inst Rech Dispositif d'entrainement et de guidage d'un produit metallique en bande soumis a une modification de temperature
EP0438130A2 (de) * 1990-01-17 1991-07-24 Sumitomo Heavy Industries, Ltd Elektromagnetisches Induktionsheizgerät
EP0438130A3 (en) * 1990-01-17 1992-03-25 Sumitomo Heavy Industries, Ltd An electromagnetic induction heater
US5157233A (en) * 1990-01-17 1992-10-20 Sumitomo Heavy Industries, Ltd. Electromagnetic induction heater for heating a continuous thin sheet without undulation

Also Published As

Publication number Publication date
FR2547402A1 (fr) 1984-12-14
EP0129160A3 (en) 1985-05-02
JPS6010581A (ja) 1985-01-19
US4595813A (en) 1986-06-17
FR2547402B1 (fr) 1988-08-12
DE3473110D1 (en) 1988-09-01
JPS628910B2 (de) 1987-02-25
EP0129160B1 (de) 1988-07-27

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