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EP0490264A1 - Channel type inductor with outer metallic casing - Google Patents

Channel type inductor with outer metallic casing Download PDF

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Publication number
EP0490264A1
EP0490264A1 EP91120869A EP91120869A EP0490264A1 EP 0490264 A1 EP0490264 A1 EP 0490264A1 EP 91120869 A EP91120869 A EP 91120869A EP 91120869 A EP91120869 A EP 91120869A EP 0490264 A1 EP0490264 A1 EP 0490264A1
Authority
EP
European Patent Office
Prior art keywords
inductor
channel
liquid metal
housing
electrical conductivity
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Withdrawn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
EP91120869A
Other languages
German (de)
French (fr)
Inventor
Bernard Dr. Nacke
Hans Werner Mauve
Karl-Heinz Idziok
Helmut Wicker
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.)
ABB Patent GmbH
Original Assignee
ABB Patent GmbH
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 ABB Patent GmbH filed Critical ABB Patent GmbH
Publication of EP0490264A1 publication Critical patent/EP0490264A1/en
Withdrawn legal-status Critical Current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
    • H05B6/16—Furnaces having endless cores
    • H05B6/20—Furnaces having endless cores having melting channel only

Definitions

  • the invention relates to a channel inductor with an outer metal housing, at least one transformer core, at least one inductor coil surrounding this transformer core and at least one liquid metal channel which is arranged between the housing and the inductor coil and is embedded in inductor ceramic.
  • Such a channel inductor with an outer metal housing is from K.-H. Brokmeier, "Inductive melting”, Girardet-Verlag, Essen, 1966, pages 12 to 15 known.
  • Channel inductors are used to flange onto liquid metal containers and usually have one or two inductor coils with corresponding liquid metal channels.
  • the design of the outer housing made of metal, preferably steel, has the disadvantage that the magnetic stray field of the liquid metal channels partially penetrates through the inductor housing or penetrates into it, or is guided through this housing itself if it consists of a magnetizable material.
  • the invention has for its object to provide a channel inductor with an outer metal housing, in which the heat loss produced due to the magnetic stray field of the liquid metal channel in the housing itself is reduced.
  • the housing is provided on its inner surface facing the liquid metal channel with a material of high electrical conductivity.
  • the advantages that can be achieved with the invention consist in particular in that the outer metal housing is quasi “shielded” or “short-circuited” by the material having high electrical conductivity.
  • the stray magnetic field of the liquid metal channel also induces parasitic currents in the material with high electrical conductivity, but because of the low electrical resistance of the material used, this results in significantly smaller amounts of Joule heat loss. Additional cooling measures to dissipate the power loss produced in the outer housing can be dispensed with.
  • Copper, or alternatively aluminum, is preferably used as the material with high electrical conductivity.
  • the housing can advantageously be coated with the material of high electrical conductivity, preferably with copper or aluminum.
  • the channel inductor 1 shows a channel inductor with an inductor coil.
  • the channel inductor 1 has a housing 2 made of metal, preferably steel, which contains the inductor ceramic 3 with the U-shaped liquid metal channel 8 (channel).
  • the transformer core 6 In the center of the channel inductor 1 there is the transformer core 6 with the inductor coil 5 surrounding it.
  • a (preferably liquid-cooled) cooling jacket 7 arranged between the inductor coil 5 and the inductor ceramic 3 serves to dissipate the heat loss produced during operation from the channel inductor 1.
  • a current flows in the inductor coil 5 which is supplied with an alternating voltage of a suitable frequency, the magnitude of which depends on the level of the active and reactive resistance.
  • This primary current generates a magnetic field, the magnetic flux of this field predominantly flowing in the transformer core 6.
  • This magnetic flux generated by the primary current in turn generates a voltage in the surrounding secondary circuit formed from the liquid metal in the liquid metal channel 8.
  • a current flows in the secondary circuit, the magnitude of which depends on the effective and reactance resistances of the liquid metal in the channel 8 (liquid metal channel).
  • the magnetic stray field of the liquid metal channel 8 also acts in the direction of the housing 2.
  • the housing 2 is provided on its inner surface facing the liquid metal channel 8 with a material 4 of high electrical conductivity, preferably copper or alternatively aluminum, preferably coated.
  • the stray magnetic field of the liquid metal channel 8 induces parasitic currents in this material 4 (preferably copper plating).
  • the power loss (Joule heat loss) produced in the material 4 due to these parasitic currents, which is proportional to the product of the quadratic value of the parasitic currents and the electrical resistance value of the material 4, is advantageously relatively low due to the low electrical resistance of the material 4.
  • FIG. 2 shows a channel inductor with two inductor coils.
  • the channel inductor 11 with its outer housing 12 made of steel, the inductor ceramic 13, two transformer cores 16, 22, two inductor coils 15, 21 surrounding the transformer cores, two cooling jackets 17, 23 surrounding the inductor coils and the overall W-shaped liquid metal channel ( Channel), consisting of a liquid metal channel section 18 assigned to the inductor coil 15, a liquid metal channel section 20 assigned to the inductor coil 21 and a central liquid metal channel section 19 assigned to both inductor coils.
  • Channel W-shaped liquid metal channel
  • the inner surface of the housing 12 facing the liquid metal channel sections 18, 19, 20 is coated with a material 14 of high electrical conductivity, preferably with copper or alternatively aluminum (copper plating).
  • a material 14 of high electrical conductivity preferably with copper or alternatively aluminum (copper plating).
  • the mode of operation of this material 14 is as described under FIG. 1.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Coils Of Transformers For General Uses (AREA)

Abstract

A channel-type inductor with outer metallic casing (2), at least one transformer core (6), at least one inductor coil (5) surrounding said transformer core, and at least one liquid metal duct (8), which is arranged between the casing and inductor coil and embedded in inductor ceramic, is proposed, the casing (2) being provided on its inner surface facing the liquid metal duct (6) with a material (4) of high electrical conductivity. This measure reduces the heat losses produced as a consequence of the magnetic stray field of the liquid metal duct (8). <IMAGE>

Description

Die Erfindung bezieht sich auf einen Rinneninduktor mit äußerem metallenem Gehäuse, mindestens einem Transformatorenkern, mindestens einer, diesen Transformatorenkern umgebenden Induktorspule und mindestens einem, zwischen Gehäuse und Induktorspule angeordneten, in Induktorkeramik eingebetteten Flüssigmetallkanal.The invention relates to a channel inductor with an outer metal housing, at least one transformer core, at least one inductor coil surrounding this transformer core and at least one liquid metal channel which is arranged between the housing and the inductor coil and is embedded in inductor ceramic.

Ein derartiger Rinneninduktor mit äußerem metallenem Gehäuse ist aus K.-H. Brokmeier, "Induktives Schmelzen", Girardet-Verlag, Essen, 1966, Seite 12 bis 15 bekannt.Such a channel inductor with an outer metal housing is from K.-H. Brokmeier, "Inductive melting", Girardet-Verlag, Essen, 1966, pages 12 to 15 known.

Rinneninduktoren dienen zum Anflanschen an Flüssigmetallbehälter und weisen meist ein oder zwei Induktorspulen mit entsprechenden Flüssigmetallkanälen auf. Die Ausführung des äußeren Gehäuses aus Metall, vorzugsweise aus Stahl, hat den Nachteil, daß das magnetische Streufeld der Flüssigmetallkanäle teilweise durch das Induktorgehäuse dringt oder in dieses hineindringt oder auch durch dieses Gehäuse selbst geführt wird, wenn es aus einem magnetisierbaren Werkstoff besteht.Channel inductors are used to flange onto liquid metal containers and usually have one or two inductor coils with corresponding liquid metal channels. The design of the outer housing made of metal, preferably steel, has the disadvantage that the magnetic stray field of the liquid metal channels partially penetrates through the inductor housing or penetrates into it, or is guided through this housing itself if it consists of a magnetizable material.

Aus diesem Grund werden in diesem Gehäuse parasitäre Ströme induziert, die dort Verlustwärme produzieren. Besonders bei Rinneninduktoren mit hoher Leistung sind diese Verluste so groß, daß sie mit entsprechenden Kühlmaßnahmen abgeführt werden müssen.For this reason, parasitic currents are induced in this housing, which produce heat loss there. Especially with channel inductors with high power, these losses are so great that they have to be dissipated with appropriate cooling measures.

Der Erfindung liegt die Aufgabe zugrunde, einen Rinneninduktor mit äußerem metallenem Gehäuse anzugeben, bei dem die infolge des magnetischen Streufeldes des Flüssigmetallkanals im Gehäuse selbst produzierte Verlustwärme herabgesetzt ist.The invention has for its object to provide a channel inductor with an outer metal housing, in which the heat loss produced due to the magnetic stray field of the liquid metal channel in the housing itself is reduced.

Diese Aufgabe wird in Verbindung mit den Merkmalen des Oberbegriffes des Anspruchs 1 erfindungsgemäß dadurch gelöst, daß das Gehäuse an seiner dem Flüssigmetallkanal zugewandten Innenfläche mit einem Werkstoff hoher elektrischer Leitfähigkeit versehen ist.This object is achieved in connection with the features of the preamble of claim 1 in that the housing is provided on its inner surface facing the liquid metal channel with a material of high electrical conductivity.

Die mit der Erfindung erzielbaren Vorteile bestehen insbesondere darin, daß das äußere metallene Gehäuse durch den Werkstoff hoher elektrischer Leitfähigkeit quasi "abgeschirmt" bzw. "kurzgeschlossen" wird. Das magnetische Streufeld des Flüssigmetallkanals induziert zwar im Werkstoff hoher elektrischer Leitfähigkeit ebenfalls parasitäre Ströme, jedoch entstehen dadurch wegen des niedrigen elektrischen Widerstandes des verwendeten Werkstoffes wesentlich geringere Mengen Joulscher Verlustwärme. Auf zusätzliche Kühlmaßnahmen zur Abführung der im äußeren Gehäuse produzierten Verlustleistung kann verzichtet werden.The advantages that can be achieved with the invention consist in particular in that the outer metal housing is quasi “shielded” or “short-circuited” by the material having high electrical conductivity. The stray magnetic field of the liquid metal channel also induces parasitic currents in the material with high electrical conductivity, but because of the low electrical resistance of the material used, this results in significantly smaller amounts of Joule heat loss. Additional cooling measures to dissipate the power loss produced in the outer housing can be dispensed with.

Als Werkstoff hoher elektrischer Leitfähigkeit wird vorzugsweise Kupfer, alternativ Aluminium verwendet.Copper, or alternatively aluminum, is preferably used as the material with high electrical conductivity.

Vorteilhaft kann das Gehäuse mit dem Werkstoff hoher elektrischer Leitfähigkeit - vorzugsweise mit Kupfer bzw. Aluminium - beschichtet werden.The housing can advantageously be coated with the material of high electrical conductivity, preferably with copper or aluminum.

Die Erfindung wird nachstehend anhand der in der Zeichnung dargestellten Ausführungsbeispiele erläutert. Es zeigen:

Fig. 1
einen Rinneninduktor mit einer Induktorspule,
Fig. 2
einen Rinneninduktor mit zwei Induktorspulen.
The invention is explained below with reference to the embodiments shown in the drawing. Show it:
Fig. 1
a channel inductor with an inductor coil,
Fig. 2
a channel inductor with two inductor coils.

In Figur 1 ist ein Rinneninduktor mit einer Induktorspule dargestellt. Der Rinneninduktor 1 weist ein Gehäuse 2 aus Metall, vorzugsweise aus Stahl auf, das die Induktorkeramik 3 mit dem U-förmigen Flüssigmetallkanal 8 (Rinne) enthält. Im Zentrum des Rinneninduktors 1 befindet sich der Transformatorenkern 6 mit der ihn umgebenden Induktorspule 5. Ein zwischen Induktorspule 5 und Induktorkeramik 3 angeordneter (vorzugsweise flüssigkeitsgekühlter) Kühlmantel 7 dient zur Abführung der während des Betriebes produzierten Verlustwärme aus dem Rinneninduktor 1.1 shows a channel inductor with an inductor coil. The channel inductor 1 has a housing 2 made of metal, preferably steel, which contains the inductor ceramic 3 with the U-shaped liquid metal channel 8 (channel). In the center of the channel inductor 1 there is the transformer core 6 with the inductor coil 5 surrounding it. A (preferably liquid-cooled) cooling jacket 7 arranged between the inductor coil 5 and the inductor ceramic 3 serves to dissipate the heat loss produced during operation from the channel inductor 1.

Wie allgemein bekannt ist, fließt in der mit einer Wechselspannung geeigneter Frequenz beaufschlagten Induktorspule 5 ein Strom, dessen Größe von der Höhe des Wirk- und Blindwiderstandes abhängt. Dieser Primärstrom erzeugt ein magnetisches Feld, wobei der magnetische Fluß dieses Feldes vorwiegend im Transformatorenkern 6 fließt. Dieser vom Primärstrom erzeugte magnetische Fluß erzeugt seinerseits in dem umschließenden, aus dem flüssigen Metall im Flüssigmetallkanal 8 gebildeten Sekundärkreis eine Spannung. Aufgrund der Höhe dieser Spannung fließt in dem Sekundärkreis ein Strom, dessen Größe von den Wirk- und Blindwiderständen des flüssigen Metalls in der Rinne 8 (Flüssigmetallkanal) abhängt. Diese induzierte Leistung wird vorwiegend in Wärmeenergie umgeformt, was zu der gewünschten Temperaturerhöhung des Rinnenmetalls (= flüssiges Metall im Flüssigmetallkanal) führt.As is generally known, a current flows in the inductor coil 5 which is supplied with an alternating voltage of a suitable frequency, the magnitude of which depends on the level of the active and reactive resistance. This primary current generates a magnetic field, the magnetic flux of this field predominantly flowing in the transformer core 6. This magnetic flux generated by the primary current in turn generates a voltage in the surrounding secondary circuit formed from the liquid metal in the liquid metal channel 8. Because of the level of this voltage, a current flows in the secondary circuit, the magnitude of which depends on the effective and reactance resistances of the liquid metal in the channel 8 (liquid metal channel). This induced power is mainly converted into thermal energy, which leads to the desired increase in the temperature of the channel metal (= liquid metal in the liquid metal channel).

Das magnetische Streufeld des Flüssigmetallkanals 8 wirkt auch in Richtung des Gehäuses 2. Das Gehäuse 2 ist an seiner dem Flüssigmetallkanal 8 zugewandten Innenfläche mit einem Werkstoff 4 hoher elektrischer Leitfähigkeit, vorzugsweise Kupfer oder alternativ Aluminium, versehen, vorzugsweise beschichtet. Das magnetische Streufeld des Flüssigmetallkanals 8 induziert in diesem Werkstoff 4 (vorzugsweise Kupferplattierung) parasitäre Ströme. Die im Werkstoff 4 aufgrund dieser parasitären Ströme produzierte Verlustleistung (Joulsche Verlustwärme), die dem Produkt aus dem quadratischen Wert der parasitären Ströme und dem elektrischen Widerstandswert des Werkstoffes 4 proportional ist, ist aufgrund des niedrigen elektrischen Widerstandes des Werkstoffes 4 vorteilhaft relativ gering.The magnetic stray field of the liquid metal channel 8 also acts in the direction of the housing 2. The housing 2 is provided on its inner surface facing the liquid metal channel 8 with a material 4 of high electrical conductivity, preferably copper or alternatively aluminum, preferably coated. The stray magnetic field of the liquid metal channel 8 induces parasitic currents in this material 4 (preferably copper plating). The power loss (Joule heat loss) produced in the material 4 due to these parasitic currents, which is proportional to the product of the quadratic value of the parasitic currents and the electrical resistance value of the material 4, is advantageously relatively low due to the low electrical resistance of the material 4.

In Figur 2 ist ein Rinneninduktor mit zwei Induktorspulen dargestellt. Im einzelnen ist der Rinneninduktor 11 mit seinem äußeren Gehäuse 12 aus Stahl, der Induktorkeramik 13, zwei Transformatorenkernen 16, 22, zwei die Transformatorenkerne jeweils umgebende Induktorspulen 15, 21, zwei die Induktorspulen umgebende Kühlmäntel 17, 23 und der insgesamt W-förmige Flüssigmetallkanal (Rinne), bestehend aus einem der Induktorspule 15 zugeordneten Flüssigmetallkanalabschnitt 18, einem der Induktorspule 21 zugeordneten Flüssigmetallkanalabschnitt 20 und einem mittleren, beiden Induktorspulen gemeinsam zugeordneten Flüssigmetallkanalabschnitt 19 zu erkennen.FIG. 2 shows a channel inductor with two inductor coils. In particular, the channel inductor 11 with its outer housing 12 made of steel, the inductor ceramic 13, two transformer cores 16, 22, two inductor coils 15, 21 surrounding the transformer cores, two cooling jackets 17, 23 surrounding the inductor coils and the overall W-shaped liquid metal channel ( Channel), consisting of a liquid metal channel section 18 assigned to the inductor coil 15, a liquid metal channel section 20 assigned to the inductor coil 21 and a central liquid metal channel section 19 assigned to both inductor coils.

Die zu den Flüssigmetallkanalabschnitten 18, 19, 20 zugewandte Innenfläche des Gehäuses 12 ist mit einem Werkstoff 14 hoher elektrischer Leitfähigkeit, vorzugsweise mit Kupfer bzw. alternativ Aluminium, beschichtet (Kupferplattierung). Die Wirkungsweise dieses Werkstoffes 14 ist wie unter Figur 1 beschrieben.The inner surface of the housing 12 facing the liquid metal channel sections 18, 19, 20 is coated with a material 14 of high electrical conductivity, preferably with copper or alternatively aluminum (copper plating). The mode of operation of this material 14 is as described under FIG. 1.

Claims (4)

Rinneninduktor mit äußerem metallenem Gehäuse, mindestens einem Transformatorenkern, mindestens einer, diesen Transformatorenkern umgebenden Induktorspule und mindestens einem, zwischen Gehäuse und Induktorspule angeordneten, in Induktorkeramik eingebetteten Flüssigmetallkanal, dadurch gekennzeichnet, daß das Gehäuse (2,12) an seiner dem Flüssigmetallkanal (8,18,19,20) zugewandten Innenfläche mit einem Werkstoff (4,14) hoher elektrischer Leitfähigkeit versehen ist.Channel inductor with an outer metal housing, at least one transformer core, at least one inductor coil surrounding this transformer core and at least one liquid metal channel which is arranged between the housing and the inductor coil and is embedded in inductor ceramic, characterized in that the housing (2, 12) is connected to the liquid metal channel (8, 18, 19, 20) facing inner surface is provided with a material (4, 14) of high electrical conductivity. Rinneninduktor nach Anspruch 1, dadurch gekennzeichnet, daß Kupfer als Werkstoff (4,14) hoher elektrischer Leitfähigkeit Verwendung findet.Channel inductor according to Claim 1, characterized in that copper is used as the material (4, 14) of high electrical conductivity. Rinneninduktor nach Anspruch 1, dadurch gekennzeichnet, daß Aluminium als Werkstoff (4,14) hoher elektrischer Leitfähigkeit Verwendung findet.Channel inductor according to Claim 1, characterized in that aluminum is used as the material (4, 14) of high electrical conductivity. Rinneninduktor nach mindestens einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß das Gehäuse (2,12) mit dem Werkstoff (4,14) hoher elektrischer Leitfähigkeit beschichtet ist.Channel inductor according to at least one of Claims 1 to 3, characterized in that the housing (2, 12) is coated with the material (4, 14) of high electrical conductivity.
EP91120869A 1990-12-11 1991-12-05 Channel type inductor with outer metallic casing Withdrawn EP0490264A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4039427 1990-12-11
DE19904039427 DE4039427A1 (en) 1990-12-11 1990-12-11 GUTTER INDUCTOR WITH OUTER METAL HOUSING

Publications (1)

Publication Number Publication Date
EP0490264A1 true EP0490264A1 (en) 1992-06-17

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE202018106993U1 (en) 2017-12-08 2019-01-03 Sms Elotherm Gmbh Apparatus for tempering a molten metal and apparatus for hot dip coating comprising such a device
DE102021121030A1 (en) 2021-08-12 2023-02-16 Otto Junker Gesellschaft mit beschränkter Haftung Device for inductively heating molten metal, multi-chamber melting furnace for melting metal scrap and method for melting metal scrap

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB792322A (en) * 1955-06-14 1958-03-26 Birlec Ltd Improvements in or relating to electric induction furnaces
US3363044A (en) * 1965-03-13 1968-01-09 Asea Ab Channel type induction furnace
DE2029420A1 (en) * 1969-06-10 1970-12-17 Inductor for electric ovens with channels - for melting iron and non ferrour metals
DE2208876A1 (en) * 1972-02-25 1973-09-06 Aeg Elotherm Gmbh INDUCTION CHANNEL, IN PARTICULAR FOR INDUCTION CHANNEL FURNACE
US4101726A (en) * 1977-01-17 1978-07-18 Atlas Foundry & Mfg. Co. Water cooling jacket for induction furnace water bushing

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB792322A (en) * 1955-06-14 1958-03-26 Birlec Ltd Improvements in or relating to electric induction furnaces
US3363044A (en) * 1965-03-13 1968-01-09 Asea Ab Channel type induction furnace
DE2029420A1 (en) * 1969-06-10 1970-12-17 Inductor for electric ovens with channels - for melting iron and non ferrour metals
DE2208876A1 (en) * 1972-02-25 1973-09-06 Aeg Elotherm Gmbh INDUCTION CHANNEL, IN PARTICULAR FOR INDUCTION CHANNEL FURNACE
US4101726A (en) * 1977-01-17 1978-07-18 Atlas Foundry & Mfg. Co. Water cooling jacket for induction furnace water bushing

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE202018106993U1 (en) 2017-12-08 2019-01-03 Sms Elotherm Gmbh Apparatus for tempering a molten metal and apparatus for hot dip coating comprising such a device
DE102021121030A1 (en) 2021-08-12 2023-02-16 Otto Junker Gesellschaft mit beschränkter Haftung Device for inductively heating molten metal, multi-chamber melting furnace for melting metal scrap and method for melting metal scrap
WO2023016820A1 (en) 2021-08-12 2023-02-16 Otto Junker Gmbh Apparatus for inductively heating molten metal, multi-chamber melting furnace for melting scrap metal, and method for melting scrap metal

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