EP0480845A1 - Induktionsschmelzofen mit kaltem Tiegel - Google Patents

Induktionsschmelzofen mit kaltem Tiegel Download PDF

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Publication number
EP0480845A1
EP0480845A1 EP91420241A EP91420241A EP0480845A1 EP 0480845 A1 EP0480845 A1 EP 0480845A1 EP 91420241 A EP91420241 A EP 91420241A EP 91420241 A EP91420241 A EP 91420241A EP 0480845 A1 EP0480845 A1 EP 0480845A1
Authority
EP
European Patent Office
Prior art keywords
crucible
sector
electromagnetic induction
wall
induction means
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.)
Withdrawn
Application number
EP91420241A
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English (en)
French (fr)
Inventor
François Schlecht
Ernst Roland
Christian Garnier
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.)
Laminoirs Du Dauphine Bonmartin Ets SA
Original Assignee
Laminoirs Du Dauphine Bonmartin Ets 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 Laminoirs Du Dauphine Bonmartin Ets SA filed Critical Laminoirs Du Dauphine Bonmartin Ets SA
Publication of EP0480845A1 publication Critical patent/EP0480845A1/de
Withdrawn legal-status Critical Current

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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
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/22—Furnaces without an endless core
    • H05B6/24—Crucible furnaces

Definitions

  • the present invention relates, in general, to induction melting furnaces in a cold crucible.
  • a major concern for such ovens is to avoid excessive heating of the wall of the crucible.
  • the arrangement in sectors electrically isolated from each other which constitute the wall of the crucible makes it possible, in known manner, to limit the effects of induction in the wall, and consequently to limit its heating.
  • this cooling is carried out by producing the parts of the wall of the crucible in a metallic material which is a good conductor of heat, for example copper, and by providing in these parts holes extending parallel to the internal wall and in which circulate a coolant, for example water.
  • a metallic material which is a good conductor of heat, for example copper
  • the ovens known to date use as a means of magnetic induction a medium frequency inductor, that is to say an inductor operating at a frequency greater than approximately 400 Hz.
  • the magnetic induction windings operating at medium frequency allow relatively low electric currents to pass, and consequently, the electric voltages appearing at the terminals of these windings or windings, are relatively large, for example greater than 80 volts. Special precautions must therefore be taken in such installations to avoid any risk of electric shock and to avoid any formation of an electric arc.
  • An object of the present invention is to provide an induction furnace with a cold wall which can have a relatively large capacity and using electromagnetic induction means of a simpler design than those present in the induction furnaces of the prior art.
  • Another object of the present invention is to provide such an oven in which the crucible is of simpler design than those of similar ovens of the prior art, while having an efficiency at least as great, that is to say while maintaining the interior wall of the oven at a sufficiently low temperature, at least as low as that of similar ovens of the prior art.
  • Another object of the present invention is to provide such an oven in which the potential differences appearing at the terminals of the various elements constituting the electromagnetic induction means remain relatively small, for example less than 40 volts, in order to ensure high safety. of the installation without having to resort to complicated protective means.
  • Yet another object of the present invention is to provide such an oven in which it is possible to obtain, in a controlled and efficient manner, stirring, even for large-capacity ovens, for example greater than 5 liters.
  • the electromagnetic induction means has a low impedance and is traversed by a relatively high current under a low voltage.
  • the electromagnetic induction means is supplied from a secondary winding of a transformer, the primary winding of which is supplied directly by the electrical sector.
  • the other generator 12 provides a much lower power output and its realization therefore does not cause any significant problem, although it delivers a current at an average frequency, that is to say much higher than the network frequency.
  • the crucible has a conventional shape comprising an upper cylindrical part and a lower spherical or conical part ending in the lowest part by an opening serving for the evacuation of the molten metal which will be contained in this crucible.
  • the wall of the crucible is not in one piece but is in fact made up of a certain number of sectors 6A, 6B, etc., which extend vertically and which are electrically isolated from each other.
  • This structure of a crucible wall comprising a number of sectors isolated from each other is known from the prior art and does not require a more detailed description here. It should be noted, however, that according to the present invention, the number of sectors that can constitute the wall of the crucible 6 can remain relatively small, for example between 4 and 12. The justification for this relatively small number of sectors will be made in the following. description.
  • All of the sectors constituting the crucible wall 6 are held in place by a box (not shown) made of electrical insulating material, conventionally made of a refractory material of the cement type.
  • This box must, however, withstand the maximum temperature that the wall of the crucible 6 can reach, although this wall is cooled, and must also resist mechanical stress and thermal shock.
  • Such a box is known from the prior art and, for this reason, will not be described in more detail here.
  • the different sectors constituting the wall of the crucible 6 are made of a metal that is a good conductor of electricity and a good conductor of heat, preferably copper.
  • Other metals can also be used, their choice essentially depending on physicochemical characteristics linked to the nature of the material to be melted in the crucible, this material being commonly called the filler.
  • each sector constituting the wall of the crucible 6 is welded a metal tube 21, the greater part of which extends substantially in a plane passing through the vertical longitudinal axis 22 of the crucible.
  • tubes 22 there are sectors 6A, 6B, etc., in the wall of the crucible.
  • Each tube 22 has a U shape and the ends of this tube located in the upper part are respectively connected to a cooling water supply pipe 23 and to a cooling water discharge pipe 24.
  • the tubes 22 are made of the same material as that of the wall, for example copper.
  • the tube can advantageously be linked to the sector by brazing.
  • the tube 22 can represent a diameter of about 10 mm and a thickness of about 1 mm, and this kind of copper tube can be commercially available easily because it actually corresponds to copper tubes in common use.
  • a magnetic yoke made of laminated material is very effective in channeling the field lines produced by coil 5 which is an induction coil.
  • coil 5 which is an induction coil.
  • the magnetic yoke 8 has the shape of a cylinder with a vertical axis coinciding with the longitudinal axis 25 of the crucible 6. Its vertical position can be adjusted by means of an appropriate adjustable support means (not shown).
  • the induction furnace according to the present invention also comprises a particular and new device having the function of a controllable valve, for the evacuation of the molten charge contained in the crucible.
  • the device consists of a vertical cylindrical wall constituting a discharge tube 35 disposed under the crucible 6, this tube 35 having a relatively small diameter, for example, of the order of 30 mm.
  • the tube 35 is cooled by a circulation of water in holes 36 formed in the tube and by supply lines 37 and discharge 38 of cooling water.
  • the excitation coil 10 is a medium frequency coil which, when energized, creates an electromagnetic induction at the center of the tube 30, which causes the material contained in this tube to melt, which allows evacuation downwards. of the molten charge.
  • the invention in its greatest generality, is based on the fact that the crucible consists essentially of a relatively thin metal wall 6.
  • the thickness of this metal wall is less than the penetration depth of the magnetic field. Since an electromagnetic induction means operating at low frequency, for example at 50 or 60 Hz, is used, this penetration depth is approximately 6 mm and therefore, a wall of the crucible made of a conductive material, for example copper, the thickness of which is less than this penetration depth, this thickness possibly being chosen for example equal to 2 mm. Under these conditions, the crucible is "transparent" to the magnetic field, and its heating is particularly low.
  • the molten material present on the surface tends to move from the outside towards the center and, arriving at the center, tends to descend to the bottom of the crucible from where it rises by the lateral edges.
  • This type of mixing takes place in the opposite direction to that which would naturally occur in the absence of the magnetic core.
  • the Applicant has noticed that this type of mixing which is reversed with respect to the natural movement is better because it avoids the accumulation on the surface, at the periphery, of stagnant solid materials which form an obstacle to homogenization. of the material being melted.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
  • General Induction Heating (AREA)
EP91420241A 1990-07-26 1991-07-11 Induktionsschmelzofen mit kaltem Tiegel Withdrawn EP0480845A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9009865 1990-07-26
FR9009865A FR2665249A1 (fr) 1990-07-26 1990-07-26 Four de fusion par induction en creuset froid.

Publications (1)

Publication Number Publication Date
EP0480845A1 true EP0480845A1 (de) 1992-04-15

Family

ID=9399335

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91420241A Withdrawn EP0480845A1 (de) 1990-07-26 1991-07-11 Induktionsschmelzofen mit kaltem Tiegel

Country Status (3)

Country Link
US (1) US5280496A (de)
EP (1) EP0480845A1 (de)
FR (1) FR2665249A1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110381618A (zh) * 2019-07-25 2019-10-25 镇江沅净电子科技有限公司 一种电磁感应加热系统及其加热方法

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2967092B2 (ja) * 1991-12-20 1999-10-25 科学技術庁金属材料技術研究所長 浮上溶解装置
JP3047056B2 (ja) * 1992-06-02 2000-05-29 科学技術庁金属材料技術研究所長 浮上溶解装置とその運転方法
DE4320766C2 (de) * 1993-06-23 2002-06-27 Ald Vacuum Techn Ag Vorrichtung zum Einschmelzen einer festen Schicht aus elektrisch leitfähigem Material
FR2708725B1 (fr) * 1993-07-29 1995-11-10 Imphy Sa Procédé de fusion d'un matériau électroconducteur dans un four de fusion par induction en creuset froid et four de fusion pour la mise en Óoeuvre de ce procédé.
JP4147604B2 (ja) * 1997-04-23 2008-09-10 神鋼電機株式会社 誘導加熱溶解炉およびその底部出湯機構
FR2766497B1 (fr) * 1997-07-25 2001-05-11 Cogema Elaboration et tirage en continu, en creusets froids inductifs, de metaux ou d'alliages
RU2115182C1 (ru) * 1997-09-09 1998-07-10 Московское государственное предприятие Объединенный эколого-технологический и научно-исследовательский центр по обезвреживанию РАО и охране окружающей среды Устройство для остекловывания радиоактивных отходов, содержащих ионообменные смолы
US6144690A (en) * 1999-03-18 2000-11-07 Kabushiki Kaishi Kobe Seiko Sho Melting method using cold crucible induction melting apparatus
US6192969B1 (en) 1999-03-22 2001-02-27 Asarco Incorporated Casting of high purity oxygen free copper
DE10328618B4 (de) * 2003-06-20 2008-04-24 Leibniz-Institut Für Festkörper- Und Werkstoffforschung Dresden E.V. Verfahren und Vorrichtung zur schmelzmetallurgischen Herstellung von Magnetlegierungen auf Nd-Fe-B-Basis
KR101218923B1 (ko) * 2010-09-15 2013-01-04 한국수력원자력 주식회사 유도코일과 용융로 일체형 유도가열식 저온용융로
CN107838423A (zh) * 2017-12-12 2018-03-27 西安科技大学 一种电磁悬浮加热式3d打印机挤出喷头
CN108672670A (zh) * 2018-06-05 2018-10-19 湖南城市学院 一种可提供压力铸造的金属铸坯连续制造装置和方法

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1655983A (en) * 1927-04-02 1928-01-10 Westinghouse Electric & Mfg Co Induction furnace
FR758937A (fr) * 1932-08-03 1934-01-26 Perfectionnements dans les fours à induction
FR804240A (fr) * 1935-06-25 1936-10-19 Siemens Ag Procédé pour la production d'un mouvement de sens déterminé dans le bain des fours à induction
FR1492063A (fr) * 1966-04-05 1967-08-18 Commissariat Energie Atomique Perfectionnement aux fours électriques haute fréquence pour la fabrication en continu de réfractaires électrofondus
FR2488245A1 (fr) * 1980-08-06 1982-02-12 Saphymo Stel Procede et dispositif de fusion par induction directe avec coulee en continu eventuelle d'un melange de deux ou plusieurs oxydes refractaires
EP0128600A2 (de) * 1983-05-06 1984-12-19 Philips Patentverwaltung GmbH Kalter Tiegel für das Erschmelzen und die Kristallisation nichtmetallischer anorganischer Verbindungen
GB2161591A (en) * 1984-07-14 1986-01-15 Ipw Limited Coreless induction furnace
EP0238425A1 (de) * 1986-03-13 1987-09-23 Technogenia S.A. Verfahren und Vorrichtung zur Herstellung hitzebeständiger Materialien durch Induktion
EP0311506A1 (de) * 1987-10-06 1989-04-12 Commissariat A L'energie Atomique Schmelztiegel für einen Induktionsofen
FR2629299A1 (fr) * 1988-03-23 1989-09-29 Commissariat Energie Atomique Systeme de brassage de matiere fondue

Family Cites Families (14)

* Cited by examiner, † Cited by third party
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US1943802A (en) * 1930-03-18 1934-01-16 Ajax Electrothermic Corp Electric induction furnace
GB1415504A (en) * 1972-05-26 1975-11-26 Apv Paralec Ltd Coreless induction furnace refining and melting apparatus and processes
US3786163A (en) * 1973-02-20 1974-01-15 Kokusai Tekko Kk Low-frequency induction furnace
US3913005A (en) * 1974-08-28 1975-10-14 Inductotherm Corp Frequency multiplier circuit for controlling harmonic currents
US4058668A (en) * 1976-03-01 1977-11-15 The United States Of America As Represented By The Secretary Of The Interior Cold crucible
SE408958B (sv) * 1976-07-05 1979-07-16 Asea Ab Forfaringssett for smeltning av metaller eller metallegeringar
US4201882A (en) * 1978-05-05 1980-05-06 Apatova Larisa D Induction melting furnace
FR2497050A1 (fr) * 1980-12-23 1982-06-25 Saphymo Stel Dispositif de fusion par induction directe en cage froide avec confinement electromagnetique de la charge fondue
FR2512066B1 (fr) * 1981-09-03 1986-05-16 Cogema Procede de separation physique d'une phase metallique et de scories dans un four a induction
JPS5855707A (ja) * 1981-09-29 1983-04-02 Fuji Electric Co Ltd 溝形誘導炉のスラグ付着量測定方法
US4446562A (en) * 1981-10-13 1984-05-01 Electric Power Rsearch Institute, Inc. Method and apparatus for measuring crucible level of molten metal
FR2531062A2 (fr) * 1981-11-06 1984-02-03 Saphymo Stel Dispositif de fusion par induction directe de substances dielectriques du genre verres ou emaux
DE3405120C2 (de) * 1984-02-14 1986-11-13 Otto Junker Gmbh, 5107 Simmerath Kernloser Induktionsofen mit Distanzmitteln zwischen den Induktionsspulen-Windungen
US5090022A (en) * 1990-05-21 1992-02-18 Inductotherm Corp. Cold crucible induction furnace

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1655983A (en) * 1927-04-02 1928-01-10 Westinghouse Electric & Mfg Co Induction furnace
FR758937A (fr) * 1932-08-03 1934-01-26 Perfectionnements dans les fours à induction
FR804240A (fr) * 1935-06-25 1936-10-19 Siemens Ag Procédé pour la production d'un mouvement de sens déterminé dans le bain des fours à induction
FR1492063A (fr) * 1966-04-05 1967-08-18 Commissariat Energie Atomique Perfectionnement aux fours électriques haute fréquence pour la fabrication en continu de réfractaires électrofondus
FR2488245A1 (fr) * 1980-08-06 1982-02-12 Saphymo Stel Procede et dispositif de fusion par induction directe avec coulee en continu eventuelle d'un melange de deux ou plusieurs oxydes refractaires
EP0128600A2 (de) * 1983-05-06 1984-12-19 Philips Patentverwaltung GmbH Kalter Tiegel für das Erschmelzen und die Kristallisation nichtmetallischer anorganischer Verbindungen
GB2161591A (en) * 1984-07-14 1986-01-15 Ipw Limited Coreless induction furnace
EP0238425A1 (de) * 1986-03-13 1987-09-23 Technogenia S.A. Verfahren und Vorrichtung zur Herstellung hitzebeständiger Materialien durch Induktion
EP0311506A1 (de) * 1987-10-06 1989-04-12 Commissariat A L'energie Atomique Schmelztiegel für einen Induktionsofen
FR2629299A1 (fr) * 1988-03-23 1989-09-29 Commissariat Energie Atomique Systeme de brassage de matiere fondue

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110381618A (zh) * 2019-07-25 2019-10-25 镇江沅净电子科技有限公司 一种电磁感应加热系统及其加热方法
CN110381618B (zh) * 2019-07-25 2021-05-25 镇江沅净电子科技有限公司 一种电磁感应加热系统及其加热方法

Also Published As

Publication number Publication date
US5280496A (en) 1994-01-18
FR2665249A1 (fr) 1992-01-31

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