EP0119877A1 - Hochfrequenzinduktionsschmelzofen und Verfahren zum Vorbereiten von keramischen Materialien mit diesem Ofen - Google Patents

Hochfrequenzinduktionsschmelzofen und Verfahren zum Vorbereiten von keramischen Materialien mit diesem Ofen Download PDF

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Publication number
EP0119877A1
EP0119877A1 EP84400249A EP84400249A EP0119877A1 EP 0119877 A1 EP0119877 A1 EP 0119877A1 EP 84400249 A EP84400249 A EP 84400249A EP 84400249 A EP84400249 A EP 84400249A EP 0119877 A1 EP0119877 A1 EP 0119877A1
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EP
European Patent Office
Prior art keywords
high frequency
furnace
oven
ceramic materials
wall
Prior art date
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Granted
Application number
EP84400249A
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English (en)
French (fr)
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EP0119877B1 (de
Inventor
René Perrier De la Bathie
Jacques Terrier
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Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
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Commissariat a lEnergie Atomique CEA
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Publication of EP0119877A1 publication Critical patent/EP0119877A1/de
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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

Definitions

  • the present invention relates to techniques for preparing ceramic materials or glasses by high frequency induction melting in an oven on the walls of which forms an insulating crust, or autocreuset.
  • ceramic oxides which are good electrical insulators at room temperature, have a resistivity P which decreases with temperature (of the order of 0.1 to 10 Ohms.cm at near their liquefaction temperature).
  • the materials to be melted are generally placed in a pot which is a good conductor of heat (generally copper), the walls of which are cooled by a circulation of water and surrounded externally by a helical coil. dale traversed by the high frequency inductor current responsible for causing by electromagnetic induction the heating of the central mass contained in the pot. Due to the energetic cooling of the cylindrical copper wall constituting the pot, a crust is formed inside against this wall and causes insulation both thermally. that electric of the hot liquid part located inside the crust and which is the seat of the release of all the induced energy.
  • the fact that the inductive helical coil is distinct from the copper crucible leads to a significant high frequency power loss (of the order of 50%) and the discontinuous nature of the preparation requires an expenditure of energy. not negligible because of the successive preheating of the materials which are obtained either by introduction into the mass of products which are good conductors of electricity, or by direct heating with external means, such as the combustion of gas for example.
  • the slot made in the cylinder constituting the wall of the oven creates a large magnetic field gradient, detrimental to the homogeneity of the inductive heating;
  • the single turn thus formed can only be powered by the high frequency generator through a transformer in the air, which leads to a significant loss of energy and a correlative drop in efficiency. of the installation.
  • the present invention specifically relates to an induction melting furnace, of a simple embodiment, making it possible to overcome the drawbacks previously recalled from the known art.
  • This furnace the wall of which constitutes both the inductor, the cold crucible for holding the molten products and the inductor of the oscillating circuit of the high frequency aperiodic generator, is characterized in that its cylindrical wall is cut along a form line helical general thus forming a single flat turn with several turns.
  • the present invention also relates to a process for the preparation of ceramic materials which, while being particularly simple to use, allows continuous manufacture of these same ceramic materials while considerably reducing wheat energy expenditure necessary for this purpose.
  • This process for preparing ceramic materials by high frequency induction melting in an oven on the walls of which forms an insulating crust or autocreuset is characterized in that the powder containing the various compounds constituting the material to be prepared is introduced, continuously , in a high frequency electric oven of the previous aperiodic type, whose single helical flat turn serves as both an inductor and a cold crucible, the molten material obtained is also continuously drawn from this oven in a chute passing through the turn .
  • an aperiodic type electric oven that is to say one containing no separate oscillating circuit and having no natural operating frequency, this being chosen by the inductor which determines it automatically by electromagnetic coupling with the product to be melted.
  • this oven is produced by helical winding of a single flat turn which serves both as an inductor system and as a cold crucible, thus eliminating the energy losses inherent in the prior art when using ovens in which the crucible was independent of the inducing coil.
  • an aperiodic generator designed according to the invention, it is the assembly of the flat coil wound helically and the material to be treated which constitutes, as has been said, the crucible, the inductor system, and the self of the oscillating circuit, the system balancing itself by placing itself at the electrical resonance by the automatic choice of the operating frequency.
  • the withdrawal of the molten material takes place, like the addition of the powder containing the various constituents, to the upper part of the furnace, in the vicinity of the free surface of the molten material. , the homogenization of the mixture of powders and ceramic materials being carried out by convective mixing of the liquid phase.
  • the furnace is filled during the first loading using two materials which are temporarily separated by a cylindrical wall, namely, between this wall and that of the furnace , a first material which will form the autocreuset, and, inside the cylindrical wall, a second material which will be melted.
  • the cylindrical wall which thus separates the two materials at the time of loading can be removed altogether when the filling is finished or, a fortiori, when the oven has reached its normal melting temperature.
  • the insulating layer of the self-crucible can be of the same nature as the product to be melted, provided that it is in a defined physical form, for example SiZr0 4 , varied borosilicate, etc.
  • the initiation of the melting of a ceramic material can be done either conventionally by gas heating, or by introduction into the material to be melted of a conductive plate, for example circular, placed substantially in the central part of the crucible, kept immobilized and supplied for the time necessary using a high frequency current.
  • the flow of liquid enamels is ensured continuously at the level of the free surface of the liquid phase by means of a cooled chute, insulated or not, which crosses the inducing coil.
  • the process which is the subject of the invention therefore makes it possible to obtain both an energy yield of very good quality, continuous overflow, self-regulating, and to minimize the means of preheating in an installation which can operate continuously for several days without stopping or starting up.
  • the process which is the subject of the invention finds numerous applications in the production of enamels and glasses for the ceramic industries as well as in the vitrification of nuclear waste.
  • FIG. 1 we see, in exploded view, how is formed the crucible 1 of the furnace using a helical winding of a flat strip 2 conductive along a cylindrical surface.
  • This structure of the furnace characteristic of the invention, is obtained by lateral cutting of the cylinder of conductive metal constituting the crucible according to a slot 14 having a substantially helical outline, so as to thus produce a single flat turn with several turns.
  • the device has two high frequency current supply terminals 3 and 4 respectively from the aperiodic generator 15. This shows the essential characteristic of this embodiment in which the single turn with several turns resulting from the winding of the strip 2 constitutes at the same time the melting crucible of the materials to be produced.
  • an arrangement of this kind requires operation in autocreuset, that is to say the formation of a solid crust of impervious material along the internal wall of the crucible to ensure the sealing of the latter.
  • a coil 5 traversed by cold water, maintains the coil and its immediate environment at a temperature low enough to produce this insulating crust.
  • a cylindrical wall 6 internal to the crucible 2 and which temporarily separates, at the time of the first loading, the peripheral material contained in the zone 7 between the crucible 2 and the cylindrical wall 6, intended to form the insulating crust (for example silica Si0 2 ) and the interior 8 of the crucible in which the materials intended to be fused by induction heating are placed such as for example silicates.
  • the cylindrical wall 6 is only used temporarily when the crucible 2 is first loaded and is removed when the crust has formed and the melting of the materials has started.
  • FIG. 3 In the installation of FIG. 3, there are successively three superimposed receptacles, namely a hopper 9 for supplying a powder mixture containing the various constituents of the materials to be prepared, said powder continuously discharging through a chute 10 into the actual induction furnace 11 which is produced according to the design described in FIG. 1 above.
  • a hopper 9 for supplying a powder mixture containing the various constituents of the materials to be prepared, said powder continuously discharging through a chute 10 into the actual induction furnace 11 which is produced according to the design described in FIG. 1 above.
  • the molten enamels contained in the furnace 11 are removed from the surface 12 of separation of the pha is liquidated by means of a chute 13 possibly itself refroded, which passes through the turn 2 of the oven 11.
  • the molten enamels then flow through the chute 13 in a conventional manner to a water tank 14 to undergo the quenching necessary for their cooling and desired shaping.
  • the furnace feed rate for this mixture was 40 kg per hour.
  • the power used was 50 kW, the frequency 350 kHz and the processing temperature 1450 ° C.
  • This process can also be applied to the production of ultra-pure products with very high melting points; this object can only be achieved if the autocreuset is formed from the material to be melted and not from a layer of material of a different chemical nature.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
  • General Induction Heating (AREA)
  • Manufacture And Refinement Of Metals (AREA)
EP84400249A 1983-02-14 1984-02-06 Hochfrequenzinduktionsschmelzofen und Verfahren zum Vorbereiten von keramischen Materialien mit diesem Ofen Expired EP0119877B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8302328 1983-02-14
FR8302328A FR2540982B1 (fr) 1983-02-14 1983-02-14 Procede de preparation de materiaux ceramiques par fusion par induction a haute frequence

Publications (2)

Publication Number Publication Date
EP0119877A1 true EP0119877A1 (de) 1984-09-26
EP0119877B1 EP0119877B1 (de) 1988-02-10

Family

ID=9285883

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84400249A Expired EP0119877B1 (de) 1983-02-14 1984-02-06 Hochfrequenzinduktionsschmelzofen und Verfahren zum Vorbereiten von keramischen Materialien mit diesem Ofen

Country Status (9)

Country Link
US (1) US4610017A (de)
EP (1) EP0119877B1 (de)
JP (1) JPS59176582A (de)
BR (1) BR8400588A (de)
CA (1) CA1240727A (de)
DE (1) DE3469335D1 (de)
ES (1) ES8502249A1 (de)
FR (1) FR2540982B1 (de)
MX (1) MX156545A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0526685A3 (en) * 1991-03-01 1995-03-01 Degussa Process of semi-continuous smelting of ceramic materials by induction furnaces with skull melting crucible, a furnace therefor and apparatus for periodical tapping
WO2024123783A3 (en) * 2022-12-06 2025-09-04 Rock Fiber, Inc. Vertical melting furnace for igneous rock fiber manufacturing

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2599482B1 (fr) * 1986-06-03 1988-07-29 Commissariat Energie Atomique Four de fusion a induction haute frequence
US4780121A (en) * 1987-04-03 1988-10-25 Ppg Industries, Inc. Method for rapid induction heating of molten glass or the like
JPH01217883A (ja) * 1988-02-25 1989-08-31 Jiyuuou:Kk 誘導加熱コイル用ボビン
JPH01158096U (de) * 1988-04-20 1989-10-31
FR2634191B1 (fr) * 1988-07-13 1991-12-27 Rhone Poulenc Chimie Procede de preparation de phosphates par fusion
EP0387374A1 (de) * 1989-03-15 1990-09-19 Vsesojuzny Nauchno-Issledovatelsky Proektno-Konstruktorsky I Tekhnologichesky Inst. Elektrotermicheskogo Oborudovania Vniieto Induktionsschmelzofen
FR2646415B1 (fr) * 1989-04-28 1992-04-03 Rhone Poulenc Chimie Halogenures de terres rares deshydrates et procede de production de ceux-ci
US5134261A (en) * 1990-03-30 1992-07-28 The United States Of America As Represented By The Secretary Of The Air Force Apparatus and method for controlling gradients in radio frequency heating
DE4106536A1 (de) * 1991-03-01 1992-09-03 Degussa Thermisch gespaltenes zirkonsilikat, verfahren zu seiner herstellung und verwendung
EP0546212B1 (de) * 1991-12-11 1998-03-11 Sumitomo Heavy Industries, Ltd Induktionsofen mit geneigter Spule
FR2797440B1 (fr) 1999-08-13 2003-08-29 Cerdec Ag Procede de production de produits a base d'oxyde de zirconium cubique stabilise, produits obtenus par ce procede et leur utilisation
DE19939772C1 (de) 1999-08-21 2001-05-03 Schott Glas Skulltiegel für das Erschmelzen oder das Läutern von Gläsern
DE10041759A1 (de) * 2000-08-25 2002-03-28 Schott Glas Vorrichtung zum Homogenisieren einer Glasschmelze
JP2006513868A (ja) * 2002-12-16 2006-04-27 アービング アイ． ダーディク， 導電性連続体に電磁的に影響を与えるシステムおよび方法
US7106016B2 (en) * 2003-07-31 2006-09-12 Siemens Energy & Automation, Inc. Inductive heating system and method for controlling discharge of electric energy from machines
EP1902455B1 (de) * 2005-07-04 2009-08-26 Recupyl S.A. Integrales recycling-verfahren für kathodische röhren
JP6372079B2 (ja) * 2013-12-27 2018-08-15 シンフォニアテクノロジー株式会社 加熱溶解装置、加熱溶解システムおよび出湯制御装置
WO2017015650A1 (en) * 2015-07-23 2017-01-26 Inductotherm Corp. Basalt processing via electric induction heating and melting
FR3092656B1 (fr) 2019-02-07 2021-03-19 Inst Polytechnique Grenoble Creuset froid
JP7392910B2 (ja) * 2019-12-09 2023-12-06 日本電気硝子株式会社 ガラス溶融装置、ガラス物品の製造方法
US12060148B2 (en) 2022-08-16 2024-08-13 Honeywell International Inc. Ground resonance detection and warning system and method
WO2024227887A1 (en) * 2023-05-02 2024-11-07 Philip Morris Products S.A. An aerosol-generating device comprising an inductor coil

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2785214A (en) * 1955-06-08 1957-03-12 Gen Engineering Company Ltd Induction melting furnace
FR1186996A (fr) * 1956-06-14 1959-09-04 Siemens Ag Creuset de fusion à refroidissement par eau, en particulier pour chauffage à haute fréquence
DE1073658B (de) * 1960-01-21 Siemens-Schuckertwerke Aktiengesellschaft, Berlin Und Erlangen Induktor, insbesondere in Wendeloder U-Form, mit an ihm angebrachten Abstandhaltern und Verfahren zu seiner Herstellung
DE1135585B (de) * 1961-07-11 1962-08-30 Heraeus Gmbh W C Spule fuer Induktionsoefen
FR1319891A (fr) * 1962-04-17 1963-03-01 Centre Nat Rech Metall Procédé et four de réchauffage et de raffinage de métal liquide, notamment d'acier liquide
FR1321144A (fr) * 1962-04-24 1963-03-15 Philips Nv Four électrique à induction
FR1329010A (fr) * 1962-04-25 1963-06-07 Acec Dispositif pour le chauffage de billettes
EP0079266A1 (de) * 1981-11-06 1983-05-18 Societe D'applications De La Physique Moderne Et De L'electronique Saphymo-Stel Einrichtung zum Induktionsschmelzen von dielektrischen Substanzen wie z.B. Glas oder Email

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1430192A (fr) * 1964-12-29 1966-03-04 Electro Refractaire Four électrique à induction à haute fréquence
US4338112A (en) * 1981-03-19 1982-07-06 Owens-Corning Fiberglas Corporation Method for controlling particulate emissions from a glass furnace
US4436551A (en) * 1981-10-26 1984-03-13 Sumitomo Heavy Industries, Ltd. Process for making steel from direct-reduced iron

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1073658B (de) * 1960-01-21 Siemens-Schuckertwerke Aktiengesellschaft, Berlin Und Erlangen Induktor, insbesondere in Wendeloder U-Form, mit an ihm angebrachten Abstandhaltern und Verfahren zu seiner Herstellung
US2785214A (en) * 1955-06-08 1957-03-12 Gen Engineering Company Ltd Induction melting furnace
FR1186996A (fr) * 1956-06-14 1959-09-04 Siemens Ag Creuset de fusion à refroidissement par eau, en particulier pour chauffage à haute fréquence
DE1135585B (de) * 1961-07-11 1962-08-30 Heraeus Gmbh W C Spule fuer Induktionsoefen
FR1319891A (fr) * 1962-04-17 1963-03-01 Centre Nat Rech Metall Procédé et four de réchauffage et de raffinage de métal liquide, notamment d'acier liquide
FR1321144A (fr) * 1962-04-24 1963-03-15 Philips Nv Four électrique à induction
FR1329010A (fr) * 1962-04-25 1963-06-07 Acec Dispositif pour le chauffage de billettes
EP0079266A1 (de) * 1981-11-06 1983-05-18 Societe D'applications De La Physique Moderne Et De L'electronique Saphymo-Stel Einrichtung zum Induktionsschmelzen von dielektrischen Substanzen wie z.B. Glas oder Email

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0526685A3 (en) * 1991-03-01 1995-03-01 Degussa Process of semi-continuous smelting of ceramic materials by induction furnaces with skull melting crucible, a furnace therefor and apparatus for periodical tapping
WO2024123783A3 (en) * 2022-12-06 2025-09-04 Rock Fiber, Inc. Vertical melting furnace for igneous rock fiber manufacturing

Also Published As

Publication number Publication date
ES529710A0 (es) 1984-12-16
ES8502249A1 (es) 1984-12-16
JPH0517473B2 (de) 1993-03-09
EP0119877B1 (de) 1988-02-10
JPS59176582A (ja) 1984-10-05
FR2540982A1 (fr) 1984-08-17
CA1240727A (en) 1988-08-16
MX156545A (es) 1988-09-08
FR2540982B1 (fr) 1988-02-05
US4610017A (en) 1986-09-02
DE3469335D1 (en) 1988-03-17
BR8400588A (pt) 1984-09-18

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