EP0512465B1 - Induction crucible furnace - Google Patents

Induction crucible furnace Download PDF

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Publication number
EP0512465B1
EP0512465B1 EP92107522A EP92107522A EP0512465B1 EP 0512465 B1 EP0512465 B1 EP 0512465B1 EP 92107522 A EP92107522 A EP 92107522A EP 92107522 A EP92107522 A EP 92107522A EP 0512465 B1 EP0512465 B1 EP 0512465B1
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EP
European Patent Office
Prior art keywords
furnace
bars
frame
crucible
induction crucible
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.)
Expired - Lifetime
Application number
EP92107522A
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German (de)
French (fr)
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EP0512465A3 (en
EP0512465A2 (en
Inventor
Horst Gillhaus
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ABB Patent GmbH
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ABB Patent GmbH
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Publication of EP0512465A3 publication Critical patent/EP0512465A3/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D1/00—Casings; Linings; Walls; Roofs
    • 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
    • F27B14/00—Crucible or pot furnaces
    • F27B14/06—Crucible or pot furnaces heated electrically, e.g. induction crucible furnaces with or without any other source of heat
    • F27B14/061—Induction furnaces
    • 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
    • F27B14/00—Crucible or pot furnaces
    • F27B14/08—Details peculiar to crucible or pot furnaces
    • 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
    • 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
    • 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
    • F27B14/00—Crucible or pot furnaces
    • F27B14/02—Crucible or pot furnaces with tilting or rocking arrangements
    • 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
    • F27B14/00—Crucible or pot furnaces
    • F27B14/08—Details peculiar to crucible or pot furnaces
    • F27B2014/0843—Lining or casing
    • 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
    • F27B14/00—Crucible or pot furnaces
    • F27B14/08—Details peculiar to crucible or pot furnaces
    • F27B2014/0862—Flux guides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D1/00—Casings; Linings; Walls; Roofs
    • F27D2001/0079—Means to assemble at least two parts of a furnace or of any device or accessory associated to its use

Definitions

  • the invention relates to an induction crucible furnace according to the preamble of claim 1.
  • Such an induction crucible furnace is known from DE-C-629 215.
  • the oven is fixed in a supporting structure and can be tilted around a peg.
  • the upper and lower ends of the arms forming the yoke are connected to each other by a ring.
  • An induction crucible furnace is generally known from ABB publication No. D ME / D 118289 D and is suitable for the inductive melting of cast iron, steel, light metal, heavy metal and alloys, the operation when trained as a medium-frequency induction crucible furnace, for example at frequencies from 125 to 1000 Hz takes place.
  • a converter is used to set an alternating voltage of a predetermined frequency.
  • the active part of the induction crucible furnace is the furnace coil, the interior of which is lined with a ceramic crucible.
  • the alternating current flowing through the furnace coil generates an alternating magnetic field, which is conducted inside the crucible through the metal insert and outside the coil through the iron sheet packets of the magnetic inferences.
  • the alternating magnetic field induces eddy currents in the metallic insert, ie electrical energy that is converted into heat. Due to the transformer principle, the furnace draws power from the feeding network, so that the feed material is melted while continuously supplying energy.
  • the electromagnetic forces acting on the melt lead to an intensive bath movement, which ensures rapid heat and material balance.
  • the furnace body consists of an upper and a lower frame ring, a number of frame bars corresponding to the number of magnetic inferences being arranged between the two frame rings.
  • Each frame rod presses the associated magnetic yoke, designed as a single package, against the furnace coil via a plurality of pressing bolts.
  • ten frame bars are provided in the induction crucible furnace according to Figure 4 of the abovementioned ABB publication. The result is a relatively complex furnace body. Furthermore, there is a relatively good conductive vibration transmission path from the furnace coil via the magnetic inferences and the relatively "flexible" frame rods with a low natural frequency to the furnace body, which results in a disturbing propagation of sound waves.
  • the invention is based on the object of specifying an induction crucible furnace of the type mentioned at the outset with reduced sound radiation, the furnace body of which can be produced in a material-saving and inexpensive manner.
  • the advantages that can be achieved with the invention consist in the fact that the proposed cage construction in the form of a cuboid, in particular a cubic bar, results in a considerable saving in material and thus in a cost saving in the furnace body. It is not necessary to provide a separate frame rod for each magnetic yoke. Free access to the furnace coil, to the magnetic short circuits with laminated cores and to the connections (electrical connections and coolant connections for coolant-cooled furnace coils and magnetic short circuits) is made possible. The space required for the same crucible size and the same electrical output is considerably reduced compared to the conventional induction crucible furnace. The overall height of the magnetic inferences can be increased radially without additional space requirement, since the frame bars pressing against the magnetic inferences are eliminated.
  • the proposed furnace body thus has the particular advantage that the generation, amplification and propagation of sound waves is considerably reduced.
  • FIG. 1 shows a top view of an induction crucible furnace.
  • the induction crucible furnace has a non-metallic, refractory, hollow cylindrical crucible 1 containing the melt 34.
  • the crucible 1, which is preferably made of ceramic, is provided with a closed base and a cover which is not shown in FIG. 1 for reasons of clarity.
  • a pouring spout 2 formed on the rim of the crucible serves to pour the melt 34 out of the furnace into a ladle.
  • a cylindrical, preferably coolant-cooled furnace coil 3 is partially wound around the crucible 1.
  • the furnace coil 3 is fed via a converter with an alternating voltage of a predeterminable frequency.
  • a series of magnetic inferences 4 with electrically active laminated cores are each arranged parallel to the furnace axis and with the formation of gaps on the outer lateral surface of the furnace coil 3.
  • the cage-type furnace body consists of four rods 6, 7, 8, 9, preferably of the same length, forming an upper, rectangular frame with a rod length A, of four rods 14, 15, 16, 17, preferably of identical length, forming a lower, rectangular frame with rod length A (see Figure 3) and preferably four columns 10, 11, 12, 13 of equal length with a rod length B for right-angled connection of the upper and lower frames.
  • the connecting surfaces of the bars and columns are drawn with hatching.
  • the magnetic inferences 4 are supported on the upper and lower frames 6, 7, 8, 9 and 14, 15, 16, 17 and pressed against the furnace coil 3.
  • the support can - but does not have to - take place via frame rings 5, which are each arranged between the magnetic inferences and the rectangular frame.
  • the frame rings 5 which may be used are also very rigid and have a high natural frequency.
  • FIG. 2 shows a side view of an induction crucible furnace.
  • the furnace body in cage construction with bars 6, 7, 8, 14, 15, 16 and columns 11, 12 can be seen.
  • the outlines of the crucible 1 are indicated by dashed lines.
  • the magnetic inferences 4 pressed against the furnace coil 3 are supported against the upper and lower frames.
  • the bottom of the furnace body is one copper-clad, folded sheet - the bottom wall 18 - covered.
  • the bottom wall 18 is preferably sound-absorbing, ie provided with sound-absorbing material.
  • FIG. 3 shows a perspective view of the furnace body in rod construction.
  • the furnace body consisting of the bars 6 to 9 of the upper frame, the bars 14 to 17 of the lower frame and the columns 10 to 13 between the upper and lower frame, can be seen.
  • the bar length A of all bars corresponds to the bar length B of all columns, so that a cubic furnace body results.
  • a furnace body with different rod lengths A and B is also possible, so that a cuboid furnace body in a cage construction is formed.
  • the rods 6 to 9, 14 to 17 and columns 10 to 13 are preferably designed as square tubes with a square cross section.
  • the bars and columns are preferably made of steel and the connections between the bars with one another and between bars and columns are preferably made by welding.
  • FIG. 4 shows a side view of an oven body with side walls.
  • the four sides of the furnace body are provided with side walls 19, 20, 21, 22 (see Figure 5).
  • the side wall 19 delimited by the bars 7, 15 and columns 11, 12 can be seen.
  • the side walls can be assembled and disassembled in a simple manner (for example using generally known screw fastening means), and are designed to be sound-insulating (ie the side walls exist itself made of sound-absorbing material or are sheets provided with sound-absorbing material) and thus represent sound and protective cladding.
  • the side walls 19 to 22 in particular reduce the sound emitted from the furnace space to the outside.
  • the side walls can also be designed as doors, flaps or shutters.
  • the side walls are provided with soundproof openings for the passage of cables and hoses (eg cooling hoses for cooling the magnetic yokes and the furnace coil).
  • the top of the induction crucible furnace is covered by an oven platform 35. Insulation against sound radiation from the furnace and furnace space can be provided on the underside of the platform 35.
  • a cover 36 serves to cover the crucible 1.
  • FIG. 5 shows a top view of a furnace body with side walls (with the furnace platform and cover removed). In addition to the arrangement according to FIG. 1, the four side walls 19 to 22 can be seen.
  • the frame ring 5 can alternatively fill the entire space between the frame 6, 7, 8, 9 and the crucible 1, the space for the furnace coil 3 and optionally for the magnetic yokes 4 being expediently omitted.
  • FIG. 6 A fastening of a magnetic yoke is shown in FIG.
  • the magnetic yoke 4 is pressed onto the furnace coil 3 by means of press bolts 25, which have a metal plate 24 and a Press the vibration-damping element 23 against the magnetic yoke 4.
  • the vibrations structure-borne noise generated by the furnace coil 3 and transmitted via the magnetic inferences 4 are considerably reduced.
  • a frame component 37 is used to guide the press bolts 25.
  • the frame component 37 can be fastened, for example, to the frame ring 5 - if present - or to the frame 6, 7, 8, 9 or 14, 15, 16, 17.
  • FIG. 7 shows a tilting device for the furnace body.
  • a L-shaped tilting frame 26 made of vertically and horizontally arranged square tubes can be seen in the side view according to FIG.
  • the tilting bearings 27, around which the induction crucible furnace is tilted when the melt is poured out, are arranged at the upper end of the vertical square tube of the tilting frame 26 and are connected to the furnace body via tilting bearing brackets 28.
  • the tilt bearing brackets 28 represent extensions of the rods 7 and 9.
  • hydraulically operated telescopic cylinders 31 are provided, which are arranged between a bearing 29 and a bearing 32.
  • the bearings 29 are located on bearing brackets 30 which are molded onto the rods 7 and 9.
  • the bearings 32 are arranged on bearing brackets 33 of the lower horizontal square tubes of the tilting frame 26.
  • the tilting kinematics are expediently designed such that the center of gravity of the induction crucible furnace is always between tilting bearings 27 and telescopic cylinders 31 during the pivoting movement about the tilting bearing axis.

Description

Die Erfindung bezieht sich auf einen Induktionstiegelofen gemäß dem Oberbegriff des Anspruchs 1.The invention relates to an induction crucible furnace according to the preamble of claim 1.

Ein solcher Induktionstiegelofen ist aus der DE-C-629 215 bekannt. Der Ofen ist in einer Tragekonstruktion befestigt und um einen Zapfen kippbar. Die oberen und unteren Enden der das Joch bildenden Arme sind durch je einen Ring miteinander verbunden.Such an induction crucible furnace is known from DE-C-629 215. The oven is fixed in a supporting structure and can be tilted around a peg. The upper and lower ends of the arms forming the yoke are connected to each other by a ring.

Ein Induktionstiegelofen ist allgemein aus der ABB-Druckschrift Nr. D ME/D 118289 D bekannt und eignet sich zum induktiven Schmelzen von Gußeisen, Stahl, Leichtmetall, Schwermetall und Legierungen, wobei der Betrieb bei Ausbildung als Mittelfrequenz-Induktionstiegelofen beispielsweise bei Frequenzen von 125 bis 1000 Hz erfolgt. Zur Einstellung einer Wechselspannung vorgegebener Frequenz wird ein Stromrichter eingesetzt.An induction crucible furnace is generally known from ABB publication No. D ME / D 118289 D and is suitable for the inductive melting of cast iron, steel, light metal, heavy metal and alloys, the operation when trained as a medium-frequency induction crucible furnace, for example at frequencies from 125 to 1000 Hz takes place. A converter is used to set an alternating voltage of a predetermined frequency.

Der aktive Teil des Induktionstiegelofens ist die Ofenspule, deren Innenraum ein keramischer Tiegel auskleidet. Der durch die Ofenspule fließende Wechselstrom erzeugt ein magnetisches Wechselfeld, das innerhalb des Ofentiegels durch das metallene Einsatzmaterial und ausserhalb der Spule durch die Eisenblechpakete der magnetischen Rückschlüsse geführt wird. Das magnetische Wechselfeld induziert im metallischen Einsatzmaterial Wirbelströme, d.h. elektrische Energie, die in Wärme umgesetzt wird. Der Ofen nimmt aufgrund des transformatorischen Prinzips aus dem speisenden Netz Leistung auf, so daß unter ständiger Energiezufuhr das Einsatzmaterial zum Schmelzen gebracht wird. Die auf die Schmelze wirkenden elektromagnetischen Kräfte führen zu einer intensiven Badbewegung, die für einen schnellen Wärme- und Stoffausgleich sorgt.The active part of the induction crucible furnace is the furnace coil, the interior of which is lined with a ceramic crucible. The alternating current flowing through the furnace coil generates an alternating magnetic field, which is conducted inside the crucible through the metal insert and outside the coil through the iron sheet packets of the magnetic inferences. The alternating magnetic field induces eddy currents in the metallic insert, ie electrical energy that is converted into heat. Due to the transformer principle, the furnace draws power from the feeding network, so that the feed material is melted while continuously supplying energy. The electromagnetic forces acting on the melt lead to an intensive bath movement, which ensures rapid heat and material balance.

Der Ofenkörper besteht gemäß der ABB-Druckschrift aus einem oberen und einem unteren Rahmenring, wobei zwischen beiden Rahmenringen eine der Anzahl der magnetischen Rückschlüsse entsprechende Zahl von Rahmenstäben angeordnet ist. Jeder Rahmenstab preßt den ihm zugeordneten, als Einzelpaket ausgebildeten magnetischen Rückschluß über mehrere Preßbolzen gegen die Ofenspule. Beim Induktionstiegelofen gemäß Bild 4 der vorstehend erwähnten ABB-Druckschrift sind beispielsweise zehn Rahmenstäbe vorgesehen. Es ergibt sich somit ein relativ aufwendiger Ofenkörper. Desweiteren ergibt sich ein relativ gut leitender Schwingungsübertragungsweg von der Ofenspule über die magnetischen Rückschlüsse und die relativ "biegeweichen" Rahmenstäbe mit tiefer Eigenfrequenz bis zum Ofenkörper, was eine störende Ausbreitung von Schallwellen zur Folge hat.According to the ABB publication, the furnace body consists of an upper and a lower frame ring, a number of frame bars corresponding to the number of magnetic inferences being arranged between the two frame rings. Each frame rod presses the associated magnetic yoke, designed as a single package, against the furnace coil via a plurality of pressing bolts. In the induction crucible furnace according to Figure 4 of the abovementioned ABB publication, for example, ten frame bars are provided. The result is a relatively complex furnace body. Furthermore, there is a relatively good conductive vibration transmission path from the furnace coil via the magnetic inferences and the relatively "flexible" frame rods with a low natural frequency to the furnace body, which results in a disturbing propagation of sound waves.

Der Erfindung liegt die Aufgabe zugrunde, einen Induktionstiegelofen der eingangs genannten Art mit reduzierter Schallabstrahlung anzugeben, dessen Ofenkörper materialsparend und preisgünstig herstellbar ist.The invention is based on the object of specifying an induction crucible furnace of the type mentioned at the outset with reduced sound radiation, the furnace body of which can be produced in a material-saving and inexpensive manner.

Diese Aufgabe wird in Verbindung mit den Merkmalen des Oberbegriffes erfindungsgemäß durch die im Kennzeichen des Anspruchs 1 angegebenen Merkmale gelöst.This object is achieved in connection with the features of the preamble according to the invention by the features specified in the characterizing part of claim 1.

Die mit der Erfindung erzielbaren Vorteile bestehen darin, daß sich durch die vorgeschlagene Käfigbauweise in quader-, insbesondere kubusförmiger Stabkonstruktion eine erhebliche Materialeinsparung und damit Kosteneinsparung beim Ofenkörper ergibt. Es ist nicht notwendig, einen eigenen Rahmenstab je magnetischem Rückschluß vorzusehen. Es wird ein freier Zugang zur Ofenspule, zu den magnetischen Rückschlüssen mit Blechpaketen und zu den Anschlüssen (elektrische Anschlüsse und Kühlmittelanschlüsse für kühlmittelgekühlte Ofenspulen und magnetische Rückschlüsse) ermöglicht. Der erforderliche Bauraum für gleiche Tiegelgröße und gleiche elektrische Leistung ist im Vergleich zum Induktionstiegelofen herkömmlicher Bauart erheblich reduziert. Die Bauhöhe der magnetischen Rückschlüsse kann ohne zusätzlichen Raumbedarf radial vergrößert werden, da die gegen die magnetischen Rückschlüsse pressenden Rahmenstäbe entfallen.The advantages that can be achieved with the invention consist in the fact that the proposed cage construction in the form of a cuboid, in particular a cubic bar, results in a considerable saving in material and thus in a cost saving in the furnace body. It is not necessary to provide a separate frame rod for each magnetic yoke. Free access to the furnace coil, to the magnetic short circuits with laminated cores and to the connections (electrical connections and coolant connections for coolant-cooled furnace coils and magnetic short circuits) is made possible. The space required for the same crucible size and the same electrical output is considerably reduced compared to the conventional induction crucible furnace. The overall height of the magnetic inferences can be increased radially without additional space requirement, since the frame bars pressing against the magnetic inferences are eliminated.

Da die Reaktionskräfte des Tiegels lediglich über den "biegesteifen" oberen bzw. unteren Rahmen mit hoher Eigenfrequenz auf den Ofenkörper übertragen werden, ergibt sich eine erheblich verminderte Schallabstrahlung infolge der durch die elektromagnetischen Vorgänge innerhalb des Induktionstiegelofens bewirkten Schwingungen. Es werden aufgrund der hohen Eigenfrequenzen der sehr steifen Rahmen lediglich entsprechend hohe, unschädliche Resonanzfrequenzen weitergeleitet, denn durch Einsatz schwingungsdämpfender Elemente zwischen Rahmen und magnetischen Rückschlüssen wird eine zusätzliche Körperschalldämmung erzielt. Die tragenden Komponenten des Ofenkörpers weisen eine relativ geringe Oberfläche auf, wodurch auch die direkte Schallabstrahlung erheblich reduziert wird. Durch Einsatz schallabsorbierender Seitenwände und/oder Bodenwand und/oder Ofenplattform sind weitere Schallabsorptionsmaßnahmen möglich, so daß sich insgesamt eine erhebliche Senkung der Lärmemission ergibt. Zusammenfassend hat der vorgeschlagene Ofenkörper neben der Materialeinsparung und Kosteneinsparung somit vor allem den Vorteil, daß die Entstehung, Verstärkung und Ausbreitung von Schallwellen erheblich reduziert wird.Since the reaction forces of the crucible are transmitted to the furnace body only via the "rigid" upper or lower frame with a high natural frequency, there is a considerably reduced sound radiation as a result of the vibrations caused by the electromagnetic processes within the induction crucible furnace. Due to the high natural frequencies of the very rigid frames, only correspondingly high, harmless resonance frequencies are passed on, because additional vibration damping is achieved by using vibration-damping elements between the frame and magnetic inferences. The load-bearing components of the furnace body have a relatively small surface, which also significantly reduces the direct sound radiation. By using sound absorbing side walls and / or bottom wall and / or furnace platform, further sound absorption measures are possible, so that overall there is a significant reduction in noise emissions. In summary, in addition to saving material and costs, the proposed furnace body thus has the particular advantage that the generation, amplification and propagation of sound waves is considerably reduced.

Weitere zweckmäßige Ausgestaltungen der Erfindung sind in den Unteransprüchen gekennzeichnet.Further expedient refinements of the invention are characterized in the subclaims.

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

Figur 1
eine Aufsicht auf einen Induktionstiegelofen,
Figur 2
eine Seitenansicht eines Induktionstiegelofens,
Figur 3
eine perspektivische Ansicht des Ofenkörpers in Stabkonstruktion,
Figur 4
eine Seitenansicht eines Ofenkörpers mit Seitenwand,
Figur 5
eine Aufsicht auf einen Ofenkörper mit Seitenwänden,
Figur 6
eine Befestigung eines magnetischen Rückschlusses,
Figur 7
eine Kippeinrichtung für den Ofenkörper.
The invention is explained below with reference to the embodiments shown in the drawing. Show it:
Figure 1
a supervision of an induction crucible furnace,
Figure 2
a side view of an induction crucible furnace,
Figure 3
a perspective view of the furnace body in rod construction,
Figure 4
a side view of an oven body with side wall,
Figure 5
a top view of a furnace body with side walls,
Figure 6
fixing a magnetic yoke,
Figure 7
a tilting device for the furnace body.

In Figur 1 ist eine Aufsicht auf einen Induktionstiegelofen dargestellt. Der Induktionstiegelofen weist einen nichtmetallischen, feuerfesten, hohlzylinderförmigen, die Schmelze 34 enthaltenden Tiegel 1 auf. Der vorzugsweise aus Keramik bestehende Tiegel 1 ist mit einem geschlossenen Boden und einem in Figur 1 aus Gründen der Übersichtlichkeit nicht dargestellten Deckel versehen. Eine am Tiegelrand angeformte Gießschnauze 2 dient zum Abgießen der Schmelze 34 aus dem Ofen in eine Gießpfanne.FIG. 1 shows a top view of an induction crucible furnace. The induction crucible furnace has a non-metallic, refractory, hollow cylindrical crucible 1 containing the melt 34. The crucible 1, which is preferably made of ceramic, is provided with a closed base and a cover which is not shown in FIG. 1 for reasons of clarity. A pouring spout 2 formed on the rim of the crucible serves to pour the melt 34 out of the furnace into a ladle.

Um den Tiegel 1 ist teilweise eine zylinderförmige, vorzugsweise kühlmittelgekühlte Ofenspule 3 gewickelt. Die Ofenspule 3 wird über einen Stromrichter mit einer Wechselspannung vorgebbarer Frequenz gespeist. An der äußeren Mantelfläche der Ofenspule 3 sind stabförmig eine Reihe magnetischer Rückschlüsse 4 mit elektrisch aktiven Blechpaketen jeweils parallel zur Ofenachse und unter Bildung von Zwischenräumen angeordnet.A cylindrical, preferably coolant-cooled furnace coil 3 is partially wound around the crucible 1. The furnace coil 3 is fed via a converter with an alternating voltage of a predeterminable frequency. A series of magnetic inferences 4 with electrically active laminated cores are each arranged parallel to the furnace axis and with the formation of gaps on the outer lateral surface of the furnace coil 3.

Der Ofenkörper in Käfigbauweise besteht aus vier vorzugsweise gleich langen, einen oberen, rechtwinkligen Rahmen bildenden Stäben 6, 7, 8, 9 mit einer Stablänge A, aus vier vorzugsweise gleich langen, einen unteren, rechtwinkligen Rahmen bildenden Stäben 14, 15, 16, 17 mit Stablänge A (siehe Figur 3) und aus vorzugsweise vier gleich langen Säulen 10, 11, 12, 13 mit einer Stablänge B zur rechtwinkligen Verbindung des oberen mit dem unteren Rahmen. Die Verbindungsflächen der Stäbe und Säulen untereinander sind schraffiert gezeichnet. Die magnetischen Rückschlüsse 4 werden über den oberen bzw. unteren Rahmen 6, 7, 8, 9 bzw. 14, 15, 16, 17 abgestützt und gegen die Ofenspule 3 gepreßt. Die Abstüzung kann - muß jedoch nicht - über Rahmenringe 5 erfolgen, die jeweils zwischen den magnetischen Rückschlüssen und den rechtwinkligen Rahmen angeordnet sind. Wie auch die Rahmen 6, 7, 8, 9 bzw. 14, 15, 16, 17 sind auch die gegebenenfalls eingesetzten Rahmenringe 5 sehr biegesteif und weisen eine hohe Eigenfrequenz auf.The cage-type furnace body consists of four rods 6, 7, 8, 9, preferably of the same length, forming an upper, rectangular frame with a rod length A, of four rods 14, 15, 16, 17, preferably of identical length, forming a lower, rectangular frame with rod length A (see Figure 3) and preferably four columns 10, 11, 12, 13 of equal length with a rod length B for right-angled connection of the upper and lower frames. The connecting surfaces of the bars and columns are drawn with hatching. The magnetic inferences 4 are supported on the upper and lower frames 6, 7, 8, 9 and 14, 15, 16, 17 and pressed against the furnace coil 3. The support can - but does not have to - take place via frame rings 5, which are each arranged between the magnetic inferences and the rectangular frame. Like the frames 6, 7, 8, 9 and 14, 15, 16, 17, the frame rings 5 which may be used are also very rigid and have a high natural frequency.

In Figur 2 ist eine Seitenansicht eines Induktionstiegelofens dargstellt. Es ist der Ofenkörper in Käfigbauweise mit Stäben 6, 7, 8, 14, 15, 16 und Säulen 11, 12 zu erkennen. Die Umrisse des Tiegels 1 sind gestrichelt angedeutet. Die gegen die Ofenspule 3 gepressten magnetischen Rückschlüsse 4 stützen sich gegen den oberen und unteren Rahmen ab. Der Boden des Ofenkörpers ist von einem kupferplattierten, gekanteten Blech - der Bodenwand 18 - abgedeckt. Die Bodenwand 18 ist vorzugsweise schalldämmend ausgebildet, d.h. mit schallabsorbierenden Material versehen.FIG. 2 shows a side view of an induction crucible furnace. The furnace body in cage construction with bars 6, 7, 8, 14, 15, 16 and columns 11, 12 can be seen. The outlines of the crucible 1 are indicated by dashed lines. The magnetic inferences 4 pressed against the furnace coil 3 are supported against the upper and lower frames. The bottom of the furnace body is one copper-clad, folded sheet - the bottom wall 18 - covered. The bottom wall 18 is preferably sound-absorbing, ie provided with sound-absorbing material.

In Figur 3 ist eine perspektivische Ansicht des Ofenkörpers in Stabkonstruktion dargestellt. Es ist der Ofenkörper, bestehend aus den Stäben 6 bis 9 des oberen Rahmens, den Stäben 14 bis 17 des unteren Rahmens und den Säulen 10 bis 13 zwischen oberem und unterem Rahmen zu erkennen. Im Ausführungsbeispiel gemäß Figur 3 entspricht die Stablänge A aller Stäbe der Stablänge B aller Säulen, so daß sich ein kubusförmiger Ofenkörper ergibt. Entsprechend den Abmessungen des Tiegels ist auch ein Ofenkörper mit jeweils unterschiedlichen Stablängen A und B möglich, so daß ein quaderförmiger Ofenkörper in Käfigbauweise gebildet wird. Die Stäbe 6 bis 9, 14 bis 17 und Säulen 10 bis 13 sind vorzugsweise als Vierkantrohre mit quadratischem Querschnitt ausgebildet. Aus statischen Gründen ist es möglich, anstelle eines Stabes oder einer Säule auch zwei, drei oder mehr Stäbe oder Säulen parallel nebeneinander vorzusehen und miteinander zu verbinden. Die Stäbe und Säulen bestehen vorzugsweise aus Stahl und die Verbindungen zwischen den Stäben untereinander und zwischen Stäben und Säulen erfolgt vorzugsweise durch Schweißen.FIG. 3 shows a perspective view of the furnace body in rod construction. The furnace body, consisting of the bars 6 to 9 of the upper frame, the bars 14 to 17 of the lower frame and the columns 10 to 13 between the upper and lower frame, can be seen. In the exemplary embodiment according to FIG. 3, the bar length A of all bars corresponds to the bar length B of all columns, so that a cubic furnace body results. According to the dimensions of the crucible, a furnace body with different rod lengths A and B is also possible, so that a cuboid furnace body in a cage construction is formed. The rods 6 to 9, 14 to 17 and columns 10 to 13 are preferably designed as square tubes with a square cross section. For static reasons it is possible to provide two, three or more rods or columns in parallel next to each other and to connect them instead of a rod or a column. The bars and columns are preferably made of steel and the connections between the bars with one another and between bars and columns are preferably made by welding.

In Figur 4 ist eine Seitenansicht eines Ofenkörpers mit Seitenwänden dargestellt. Die vier Seiten des Ofenkörpers sind mit Seitenwänden 19, 20, 21, 22 versehen (siehe Figur 5). Im Auführungsbeispiel gemäß Figur 4 ist die durch die Stäbe 7, 15 und Säulen 11, 12 begrenzte Seitenwand 19 zu erkennen. Die Seitenwände sind in einfacher Weise montier- und demontierbar (z.B. unter Einsatz von allgemein bekannten Schraubbefestigungsmitteln), schalldämmend ausgebildet (d.h. die Seitenwände bestehen selbst aus schallabsorbierendem Material oder sind mit schallabsorbierendem Material versehene Bleche) und stellen somit eine Schall- und Schutzverkleidung dar. Die Seitenwände 19 bis 22 reduzieren insbesondere den aus dem Ofenraum nach außen abgestrahlten Schall. Die Seitenwände können auch als Türen, Klappen oder Rolladen ausgebildet sein. Zur Durchführung von Kabeln und Schläuchen (z.B. Kühlschläuchen zur Kühlung der magnetischen Rückschlüsse und der Ofenspule) sind die Seitenwände mit schalldichten Öffnungen versehen.FIG. 4 shows a side view of an oven body with side walls. The four sides of the furnace body are provided with side walls 19, 20, 21, 22 (see Figure 5). In the exemplary embodiment according to FIG. 4, the side wall 19 delimited by the bars 7, 15 and columns 11, 12 can be seen. The side walls can be assembled and disassembled in a simple manner (for example using generally known screw fastening means), and are designed to be sound-insulating (ie the side walls exist itself made of sound-absorbing material or are sheets provided with sound-absorbing material) and thus represent sound and protective cladding. The side walls 19 to 22 in particular reduce the sound emitted from the furnace space to the outside. The side walls can also be designed as doors, flaps or shutters. The side walls are provided with soundproof openings for the passage of cables and hoses (eg cooling hoses for cooling the magnetic yokes and the furnace coil).

Nach Demontage einer oder mehrerer Seitenwände ist ein freier Zugang zur Ofenspule 3, zu den magnetischen Rückschlüssen 4 sowie zu den elektrischen Anschlüssen und Kühlmittelanschlüssen möglich.After dismantling one or more side walls, free access to the furnace coil 3, to the magnetic yokes 4 as well as to the electrical connections and coolant connections is possible.

Die Oberseite des Induktionstiegelofens ist durch eine Ofenplattform 35 abgedeckt. An der Unterseite der Plattform 35 kann eine Isolierung gegen Schallabstrahlung vom Ofen und Ofenraum vorgesehen sein. Zur Abdeckung des Tiegels 1 dient ein Deckel 36.The top of the induction crucible furnace is covered by an oven platform 35. Insulation against sound radiation from the furnace and furnace space can be provided on the underside of the platform 35. A cover 36 serves to cover the crucible 1.

In Figur 5 ist eine Aufsicht auf einen Ofenkörper mit Seitenwänden dargestellt (bei entfernter Ofenplattform und entferntem Deckel). Zusätzlich zur Anordnung gemäß Figur 1 sind die vier Seitenwände 19 bis 22 zu erkennen. In Figur 5 ist angedeutet, daß der Rahmenring 5 alternativ den gesamten Raum zwischen Rahmen 6, 7, 8, 9 und Tiegel 1 ausfüllen kann, wobei zweckmäßig der Raum für die Ofenspule 3 und gegebenenfalls für die magnetischen Rückschlüsse 4 ausgespart ist.FIG. 5 shows a top view of a furnace body with side walls (with the furnace platform and cover removed). In addition to the arrangement according to FIG. 1, the four side walls 19 to 22 can be seen. In FIG. 5 it is indicated that the frame ring 5 can alternatively fill the entire space between the frame 6, 7, 8, 9 and the crucible 1, the space for the furnace coil 3 and optionally for the magnetic yokes 4 being expediently omitted.

In Figur 6 ist eine Befestigung eines magnetischen Rückschlusses dargestellt. Die Anpressung des magnetischen Rückschlusses 4 an die Ofenspule 3 erfolgt über Preßbolzen 25, die über eine metallene Platte 24 und ein schwingungsdämpfendes Element 23 gegen den magnetischen Rückschluß 4 drücken. Durch Einsatz der schwingungsdämpfenden Elemente 23 werden die von der Ofenspule 3 erzeugten und über die magnetischen Rückschlüsse 4 übertragenen Schwingungen (Körperschall) erheblich reduziert. Zur Führung der Preßbolzen 25 dient gemäß Figur 6 ein Rahmenbauteil 37. Das Rahmenbauteil 37 kann beispielsweise am Rahmenring 5 - soweit vorhanden - oder am Rahmen 6, 7, 8, 9 bzw. 14, 15, 16, 17 befestigt sein. Bei der Befestigung der magnetischen Rückschlüsse 4 ist prinzipiell darauf zu achten, daß diese frei zugänglich sind, so daß eine Demontage - z.B. zu Reparaturzwecken - in einfacher Weise möglich ist.A fastening of a magnetic yoke is shown in FIG. The magnetic yoke 4 is pressed onto the furnace coil 3 by means of press bolts 25, which have a metal plate 24 and a Press the vibration-damping element 23 against the magnetic yoke 4. By using the vibration-damping elements 23, the vibrations (structure-borne noise) generated by the furnace coil 3 and transmitted via the magnetic inferences 4 are considerably reduced. According to FIG. 6, a frame component 37 is used to guide the press bolts 25. The frame component 37 can be fastened, for example, to the frame ring 5 - if present - or to the frame 6, 7, 8, 9 or 14, 15, 16, 17. When attaching the magnetic inferences 4, it must in principle be ensured that they are freely accessible so that disassembly - for example for repair purposes - is possible in a simple manner.

In Figur 7 ist eine Kippeinrichtung für den Ofenkörper dargestellt. Es ist ein in der Seitenansicht gemäß Figur 7 L-förmiges Kippgestell 26 aus vertikal und horizontal angeordneten Vierkantrohren zu erkennen. Die Kipplager 27, um die der Induktionstiegelofen beim Ausgießen der Schmelze gekippt wird, sind am oberen Ende des vertikalen Vierkantrohres des Kippgestelles 26 angeordnet und über Kipplagerhalterungen 28 mit dem Ofenkörper verbunden. Die Kipplagerhalterungen 28 stellen Verlängerungen der Stäbe 7 und 9 dar. Zur Drehbewegung des Ofenkörpers um die Kipplagerachse sind hydraulisch betätigte Teleskopzylinder 31 vorgesehen, die zwischen einem Lager 29 und einem Lager 32 angeordnet sind. Die Lager 29 befinden sich an Lagerhalterungen 30, die an den Stäben 7 und 9 angeformt sind. Die Lager 32 sind an Lagerhalterungen 33 der unteren horizontalen Vierkantrohre des Kippgestelles 26 angeordnet. Die Kippkinematik ist zweckmäßig derart gestaltet, daß der Schwerpunkt des Induktionstiegelofen während der Schwenkbewegung um die Kipplagerachse stets zwischen Kipplagern 27 und Teleskopzylindern 31 liegt.FIG. 7 shows a tilting device for the furnace body. A L-shaped tilting frame 26 made of vertically and horizontally arranged square tubes can be seen in the side view according to FIG. The tilting bearings 27, around which the induction crucible furnace is tilted when the melt is poured out, are arranged at the upper end of the vertical square tube of the tilting frame 26 and are connected to the furnace body via tilting bearing brackets 28. The tilt bearing brackets 28 represent extensions of the rods 7 and 9. For the rotary movement of the furnace body about the tilt bearing axis, hydraulically operated telescopic cylinders 31 are provided, which are arranged between a bearing 29 and a bearing 32. The bearings 29 are located on bearing brackets 30 which are molded onto the rods 7 and 9. The bearings 32 are arranged on bearing brackets 33 of the lower horizontal square tubes of the tilting frame 26. The tilting kinematics are expediently designed such that the center of gravity of the induction crucible furnace is always between tilting bearings 27 and telescopic cylinders 31 during the pivoting movement about the tilting bearing axis.

Claims (6)

  1. Induction crucible furnace with a hollow-cylindrical crucible (1), a furnace coil (3) partially enveloping the crucible, a plurality of magnetic yokes (4) which are pressed against the furnace coil and are parallel to the furnace axis, and a cuboidal, in particular cubic, furnace body of cage-type construction with a top frame assembled at right angles from at least four bars (6, 7, 8, 9), a bottom frame assembled at right angles from at least four bars (14, 15, 16, 17), and at least one pillar (10, 11, 12, 13) at each corner for the purpose of connecting the two frames at right angles to form a cuboid, in particular cube, an upper frame ring (5) being arranged within the bars (6, 7, 8, 9) of the top frame and a lower frame ring (5) being arranged within the bars (14, 15, 16, 17) of the bottom frame, both frame rings being suitable for the purpose of pressing the magnetic yokes (4) against the furnace coil (3), characterized in that the magnetic yokes (4) are pressed against the furnace coil (3) via vibration-damping elements (23).
  2. Induction crucible furnace according to Claim 2, characterized by a tetrahedral design of the bars (6 to 9, 14 to 17) and/or pillars (10 to 13) with a preferably square cross-section.
  3. Induction crucible furnace according to Claim 1 and/or 2, characterized in that the side faces of the furnace body, which are bounded by bars (6 to 9, 14 to 17) and pillars (10 to 13), are provided with rectangular, in particular square, side walls (19, 20, 21, 22).
  4. Induction crucible furnace according to at least one of Claims 1 to 3, characterized in that the bottom of the furnace body, the said bottom being bounded by the bars (14 to 17) of the bottom frame, is provided with a bottom wall (18).
  5. Induction crucible furnace according to at least one of Claims 1 to 4, characterized in that the top side of the furnace body, the said top side being bounded by the bars (6, 7, 8, 9) of the top frame, is provided with a furnace platform (35), an opening being left in the furnace platform for the cover (36) of the crucible (1).
  6. Induction crucible furnace according to at least one of Claims 3 to 5, characterized in that the said walls (19 to 22) and/or the bottom wall (18) and/or the furnace platform (35) are of sound-deadening design.
EP92107522A 1991-05-10 1992-05-04 Induction crucible furnace Expired - Lifetime EP0512465B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4115279 1991-05-10
DE4115279A DE4115279A1 (en) 1991-05-10 1991-05-10 INDUCTION POT OVEN

Publications (3)

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EP0512465A2 EP0512465A2 (en) 1992-11-11
EP0512465A3 EP0512465A3 (en) 1993-09-22
EP0512465B1 true EP0512465B1 (en) 1996-07-31

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EP92107522A Expired - Lifetime EP0512465B1 (en) 1991-05-10 1992-05-04 Induction crucible furnace

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EP (1) EP0512465B1 (en)
DE (2) DE4115279A1 (en)
ES (1) ES2091357T3 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8187296B2 (en) 1992-06-02 2012-05-29 Tyco Healthcare Group Lp Apparatus and method for developing an anatomic space for laparoscopic hernia repair and patch for use therewith

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108981395B (en) * 2018-06-12 2020-02-07 京东方科技集团股份有限公司 Furnace body package assembly and equipment for heat treatment

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Publication number Priority date Publication date Assignee Title
DE1050025B (en) * 1959-02-05
US1879361A (en) * 1928-07-24 1932-09-27 Ajax Electrothermic Corp Electric induction furnace
DE629215C (en) * 1928-07-25 1936-04-24 Hirsch Kupfer Und Messingwerke Coreless induction furnace with an induction coil surrounded by a yoke
DE973041C (en) * 1947-10-31 1959-11-19 Asea Ab Tiltable electric melting furnace
FR1220513A (en) * 1963-06-20 1960-05-25 Junker Otto Coreless induction furnace
DD102802A1 (en) * 1973-04-19 1973-12-20

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8187296B2 (en) 1992-06-02 2012-05-29 Tyco Healthcare Group Lp Apparatus and method for developing an anatomic space for laparoscopic hernia repair and patch for use therewith

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DE4115279A1 (en) 1992-11-12
EP0512465A3 (en) 1993-09-22
EP0512465A2 (en) 1992-11-11
DE59206833D1 (en) 1996-09-05
ES2091357T3 (en) 1996-11-01

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