Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/34—Methods of heating
  • C21D1/42—Induction heating
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/561—Continuous furnaces for strip or wire with a controlled atmosphere or vacuum
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/60—Continuous furnaces for strip or wire with induction heating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/28—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity for treating continuous lengths of work
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
  • F27B9/36—Arrangements of 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
  • H05B6/365—Coil arrangements using supplementary conductive or ferromagnetic pieces
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/25—Process efficiency

Definitions

• INDUCTION OVEN FOR PROCESSING BANDS, SHEETS, PLATES, IN ELECTRICITY CONDUCTING MATERIAL, AND INDUCTOR FOR SUCH AN OVEN.
• the invention relates to a heat treatment furnace of strips, sheets, plates, of electrically conductive material, in particular metallic, which pass through the furnace consisting of a closed volume maintained under a gas atmosphere, which comprises a heating section with at least one inductor formed of a pair of transverse or pseudo-transverse half-inductors.
• EP 1 148 762 discloses a transverse flux induction heating device.
• the transverse flux inductors allow the heating of metal strips for thermal treatments up to temperatures typically of 750 ° C. for carbon steels or 1150 ° C. for stainless steels. At these temperatures, the bands radiate significantly which can adversely affect the operation of the inductor, in particular adversely affect the behavior of its coils, magnetic yokes, control screens, motors and actuators, cooling elements.
• a thermal protection between the band and the inductor for example a device such as that described in EP 1 349 431.
• This device is composed of a sealed enclosure gas and vacuum placed in front of the inductor, enclosure that surrounds the strip and is connected at its ends to the upstream and downstream parts of the furnace.
• the enclosure comprises a gas-tight sheath and a heat shield on the inner faces of the sheath.
• the heating inductors are arranged outside the enclosure.
• the oven is interrupted in the inductor section, in the vertical direction, at the enclosure.
• This enclosure must be transparent to the magnetic flux and the thinnest possible so, for a given inductor gap, leave the largest possible passage to the tape to avoid contact between tape and screen that can cause surface defects on the product constituted by the band.
• WO 00/52965 also has a thermal protection for transverse flux heating inductors with sealed enclosure.
• This protection includes an enclosure with a closed contour surrounding the band and gas-tight. Although the connection to the upstream and downstream sections of the oven is not explained, the implementation of such protection with heat shield causes an interruption of the oven.
• the enclosure must jointly perform the functions of gas-tightness and thermal barrier to the radiation of the heated product.
• the manufacture of the enclosure must be carried out with materials transparent to the magnetic flux and implements complex technologies that make the assembly expensive, fragile and delicate to use and maintain in good condition for long periods corresponding to the lifetimes ovens on which the speakers are mounted.
• a robust implementation of this type of enclosure leads to significant wall thicknesses that reduce the small size of the window passage of the band.
• the object of the invention is, above all, to propose a heat treatment furnace in which the transverse or pseudo-transverse flow heating can be carried out in a safe manner and without requiring, in the zone of the heating inductors, relatively complicated equipment and expensive manufacturing. It is desirable, moreover, that the installation of the inductors does not require an interruption of the oven over its entire section.
• a heat treatment furnace of the kind defined previously for strips, sheets, plates of electrically conductive material, in particular metal, which pass through the furnace is characterized in that, in the heating section, at the at least two furnace walls each comprise an opening opposite each of the two half-inductors, and two magnetic flux-transparent panels which sealing and dismount respectively seal said openings.
• each magnetic flux transparent panel is equipped with a heat shield.
• the panel with heat shield can be fixed to the wall of the oven in a sealed manner and removable by holding means.
• the panel with heat shield is attached to the half-inductor in the manner of a shield.
• the oven walls usually made of sheet metal, extend into the heating section.
• the transparent panels with heat shields located on each side of the strip are independent of each other.
• Each half-inductor can be housed in a chest delimited by walls projecting towards the outside of the furnace, this box being isolated in a manner tightness of the interior volume of the oven.
• the trunk can be attached to the oven wall.
• the box is delimited, at least in part, by folded areas of the sheet metal wall of the oven.
• the trunk housing for each half-inductor may be under a nitrogen atmosphere, or more generally an inert gas, at overpressure relative to the ambient atmosphere.
• the chest can be overpressurized with respect to the atmosphere of the oven.
• Cooling means are advantageously provided in the trunk so that the temperature is bearable by the half-inductor, in particular about 50 ° C.
• Fig. 1 is a schematic section through a vertical plane of a portion of a heat treatment line according to the invention.
• Fig. 2 is a schematic section along line H-II of FIG. 1.
• Fig.3 is a simplified schematic perspective view, on a larger scale, with parts torn from the area of the treatment furnace corresponding to the heating section, without heating inductor or closure panel.
• Fig.4 is a schematic perspective view of a closure panel of the heating section.
• Fig.5 is a schematic sectional view through a horizontal plane of the heating section, and
• Fig.6 is a partial schematic sectional view through a horizontal plane, on a larger scale, of a variant of fixing the panel.
• the band 1 moves vertically between two rollers respectively lower 2 and upper 3. This example is not limiting, and the band 1 could scroll horizontally, the following explanations being transposable to such a configuration.
• the treatment line comprises an oven 4, generally of substantially rectangular cross-section.
• the oven 4 comprises at at least one heating section 5 equipped on each side of the strip with a transverse or pseudo-transverse half-inductor 11a, 11b.
• a pair of half-inductors 11a, 11b constitutes a heating inductor.
• several identical or similar heating sections may be placed one after the other on the same vertical strand or on several parallel strands. Each heating section will be carried out identically or similarly to the following explanations.
• the oven 4 is also equipped with at least one cooling section 6 downstream of the heating section or sections, as well as equipment (not shown) for controlling the atmosphere inside the oven. These equipment made according to the state of the art are not detailed here.
• the oven 4 constitutes a closed volume, with sealing means E at the inlet and the outlet of the strip 1, maintained under a gas atmosphere.
• the gas is advantageously formed by a mixture of inert gas, such as nitrogen, and hydrogen, in particular more than 5% hydrogen by volume to promote heat exchange, and in particular in the cooling section 6 which communicates with the heating section.
• the heating section 5 may be preceded by a treatment chamber 7 ensuring, for example, preheating.
• Each half-inductor 11a, 11b is housed in a trunk 8a, 8b provided projecting outwardly on a respective wall of the furnace.
• the walls limiting each trunk 8a, 8b establish a sealed barrier between the interior volume of the trunk and the outside atmosphere.
• Each box 8a, 8b can be made of sheet steel, for example in a rectangular parallelepiped shape.
• the connection of the box with the walls of the furnace may be provided by welding beads along the edges adjacent to the walls 9.
• the boxes 8a, 8b instead of being attached to the walls 9 may be delimited, at least in part, by folded areas of the sheet of these walls.
• the walls 9 of the oven comprise, in their large facing faces, an opening 10 opposite each half-inductor, not shown in FIG.
• the walls of the furnace generally made of steel sheet 9t optionally coated with refractory 9r (see Fig.6), extend in the heating section.
• the small faces and large faces, whose portions 9a (Fig.3) surround the openings 10, are thus continuous in the vertical direction, and are not interrupted along an entire cross section at the inductors.
• the walls of the boxes 8a, 8b around each half-inductor 11a, 11b can be made by extending and forming, with folded parts, the sheet metal walls 9 of the furnace.
• the panel 12 is advantageously flat.
• Such a panel may be made of composite material, epoxy resin or the like or ceramic material or fiberglass or laminate. This type of panel is particularly resistant mechanically and thermally, and has no fragile areas.
• the transparent panels 12 located on each side of the strip 1 are independent of each other.
• the heat shield 13 may be constituted, for example as provided in EP 1 349 431, by a matrix of blocks (not shown) of refractory material which surrounds cooling water circulation tubes (not shown).
• the cooling tubes can be made in the form of coils.
• the heat shield 13 is fixed against the face of the panel 12 facing the strip 1.
• the face of the heat shield 13 facing the strip 1 is preferably located in the plane of the inner face of the wall 9 of the oven, or in the vicinity of this plane.
• the panel 12 is generally rectangular in shape, as is the opening 10.
• each panel 12 with heat shield 13 is fixed gastight to the walls 9 of the oven as shown in FIG. Fixing can be carried out using flanges 14, 15 provided at the edge of the panel 12 and the contour of the openings 10, with clamping bolts 16 passing through the flanges.
• a temperature-resistant seal 17 is disposed between the flanges 14 and 15.
• each box 8a, 8b is separated from the atmosphere of the furnace and can be placed under an atmosphere of an inert gas, especially nitrogen, at a slight excess pressure with respect to the ambient atmosphere, and in overpressure also with respect to the oven.
• the flange 14 provided at the edge of the panel 12 is formed by an angle 19 fixed by a wing 19a against the rear of the panel outside the area of the magnetic flux.
• the other wing 19b of the bracket is adjacent to the flange 15 formed by a return of the sheet 9t of the oven wall.
• a sealed seal 20 adjacent rear edges of the wing 19b and the flange 15 ensures the closure of the housing housing the half-inductor.
• the removable character of the panel 12 remains because the solder 20 can be cut without altering the panel.
• Cooling means 21 for example coils in which cooling water circulates, are advantageously provided in the boxes 8a, 8b to maintain a sufficiently low temperature that is tolerable by the half-inductors, especially a temperature about 50 ° C.
• the panel 12 with heat shield 13 is attached to the walls 9 of the oven and half-inductors 11a, 11b are also attached to the walls of the oven by means not shown.
• the panel 12 with heat shield can be attached to the corresponding half-inductor 11a, 11b, in the manner of a shield.
• the placing of the panels 12 and half-inductors in the boxes 8a, 8b is ensured by providing, for example, a plate 22 (Fig.3) closing the box on its side parallel to the strip 1.
• the plate 22 is fixed to the other walls of the trunk in a sealed and removable manner.
• the magnetic flux transparent panels according to the invention are particularly strong and easy to manufacture. They can be easily set up and dismantled. Each panel being independent, maintenance and replacement panel operations are simplified.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Materials Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Thermal Sciences (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• General Engineering & Computer Science (AREA)
• Electromagnetism (AREA)
• Furnace Details (AREA)
• Tunnel Furnaces (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=35708492

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Family Cites Families (4)

• 2005
  • 2005-06-24 FR FR0506462A patent/FR2887737B1/fr not_active Expired - Fee Related
• 2006
  • 2006-06-21 EP EP06778632A patent/EP1900256A1/de not_active Withdrawn
  • 2006-06-21 WO PCT/FR2006/001403 patent/WO2006136702A1/fr active Application Filing

Non-Patent Citations (1)

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