EP0219650A1 - Arrangement of contact electrodes for direct-current arc furnaces or resistance-melting furnaces - Google Patents

Arrangement of contact electrodes for direct-current arc furnaces or resistance-melting furnaces Download PDF

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Publication number
EP0219650A1
EP0219650A1 EP86111685A EP86111685A EP0219650A1 EP 0219650 A1 EP0219650 A1 EP 0219650A1 EP 86111685 A EP86111685 A EP 86111685A EP 86111685 A EP86111685 A EP 86111685A EP 0219650 A1 EP0219650 A1 EP 0219650A1
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EP
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Prior art keywords
contact electrode
furnace
electrode assembly
contact
arc
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EP86111685A
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German (de)
French (fr)
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EP0219650B1 (en
Inventor
Heinz Guido
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MAN Gutehoffnungshutte GmbH
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MAN Gutehoffnungshutte GmbH
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Priority to AT86111685T priority Critical patent/ATE62577T1/en
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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
    • H05B3/00—Ohmic-resistance heating
    • H05B3/02—Details
    • H05B3/03—Electrodes
    • 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
    • H05B7/00—Heating by electric discharge
    • H05B7/02—Details
    • H05B7/06—Electrodes

Definitions

  • the invention relates to a direct-current arc or resistance melting furnace, in particular an exchangeable contact electrode arrangement, the contact electrode consisting of a metallic support plate, furthermore a metal base plate arranged at a distance therefrom and connected to the support plate by means of bolts, one or more metallic contact rods, which are attached with their necks to the base plate, a refractory stamping out between the upper edge of the contact rods and the support plate and power and coolant lines arranged below the base plate.
  • an arc furnace as a direct current furnace with a cathodically polarized graphite electrode and an anodically polarized contact electrode in the furnace base also has the advantage of significantly reduced graphite electrode consumption. Another advantage is the significantly lower noise level.
  • the structure and mode of operation of direct current arc furnaces are known from numerous publications.
  • the component that is essential for practical furnace operation is the contact electrode in the furnace vessel, which on the one hand must ensure good electrical contact with the scrap used or in the later course of the melting process with the liquid metal, but on the other hand is exposed to high thermal loads.
  • Such a contact electrode is known from DE-PS 3l O6 74l.
  • the contact electrodes in the DC arc furnace are subject to premature wear in relation to the furnace hearth lining. Since the replacement of individual contact rods means a relatively large amount of work, in practice it has been decided to replace all the contact rods together at appropriate intervals.
  • This mode of operation has the defect that the insertion of the contact rods, the tamping of the center of the furnace floor and the subsequent drying process of the ramming mass delay the restart of the furnace. Furthermore, tamping the center of the furnace floor inside the hot furnace is difficult for the personnel.
  • the object of the invention is to improve the contact electrode arrangement, as proposed according to DE-PS 3l O6 74l, in the direction of simpler and faster production, assembly and disassembly.
  • the contact electrode arrangement is therefore designed and manufactured as a complete component of the melting furnace.
  • This component is inserted into the furnace vessel with a circular opening on the bottom by means of a crane.
  • suspension elements eyelets
  • the assembly is lowered into the furnace vessel and sits on the ring-shaped stiffening in the furnace vessel with its support plate.
  • the base plate to which the power and coolant lines are connected hangs down through the furnace opening.
  • the suspension means mentioned on the top of the contact electrode assembly have done their job after lowering and placing the assembly on the bottom of the furnace vessel and melt during operation of the furnace.
  • the pressure elements telescopic cylinder
  • the contact electrode is first broken out of the pounding compound with a large compressive force and then pushed upwards so far that the gripper of a traction means located above the open furnace vessel can grip around the contact electrode and pull it up out of the furnace.
  • the replacement of the contact electrode assembly can also be carried out in such a way that, after the last batch, a residual melt is left on the hearth of the furnace and suitable eyelets are inserted into this melt puts. These eyelets get their hold after the melt has cooled. Now that the contact electrode has only been broken out of the composite in the furnace vessel with the help of the pressure elements (telescopic cylinder), the support eyelets have sufficient hold in the residual melt located above the contact electrode, so that the contact electrode, which has already been released from the furnace vessel, can be lifted up without difficulty by a traction device can be pulled out. Subsequently, the insertion of a new contact electrode assembly can take place in the manner already described.
  • the furnace vessel of a direct current arc furnace shown in the figures has a steel jacket 1 and a steel vessel base 7.
  • the furnace vessel is provided with a refractory lining 2.
  • the contact electrode is inserted as a compact structural unit in the annular bottom recess of the furnace vessel.
  • the contact electrode assembly is completely created outside the furnace.
  • the structural unit consists of a support plate 3, a base plate 4 arranged at a distance below it and connected to the support plate 3 by means of bolts 5.
  • the space l3 of the contact electrode from the upper edge of the contact rods 6 to the support plate 3 is stamped out in such a way that a template is arranged around the contact electrode, which is removed again after the stamping out has solidified.
  • the upper side of the contact electrode assembly has at least one suspension element (lifting eye), against which the hook of the traction mechanism is attached, with which the entire contact electrode assembly is lowered into the furnace vessel from above.
  • the contact electrode is placed with its support plate 3 on the edge of the annular bottom recess and connected to the furnace vessel by suitable means.
  • the annular gap 11 between the construction used and the refractory lining 2 of the furnace vessel 1 is stamped out with refractory material.
  • the suspension means (lifting eyes), not shown, melt during the first furnace operation.
  • the exchange of the used contact electrode takes place in such a way that after the furnace has been emptied, the pressure elements (telescopic cylinder 10) located on the cantilever claws 9 of the annular stiffening 8 extending below the furnace vessel are extended and the complete contact electrode assembly is removed from the stamping compound is broken out with the furnace vessel. As soon as the break-out has taken place, the telescopic cylinders 10 can be extended further so that the contact electrode emerges from the hearth of the furnace vessel to such an extent that it can be gripped and pulled out by the gripper of a crane (not shown) located above the open furnace.
  • An alternative to replacing the contact electrode assembly provides that a residual melt 17 is left in the hearth floor after the last batch of the furnace. At least one support eyelet l4 is let into this residual melt l7, to which, after the residual melt l7 has cooled, a traction means is struck, which pulls the contact electrode assembly upward out of the furnace vessel after the contact electrode has previously been arranged with the aid of the pressure elements lO (below the furnace vessel ( Telescopic cylinder) has been broken out of the association with the furnace vessel by raising the telescopic cylinder.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Discharge Heating (AREA)
  • Furnace Details (AREA)

Abstract

A direct current arc or resistance melting furnace includes a contact electrode produced as an exchangeable assembly outside the furnace and introduced into an opening provided in the bottom of the furnace tank. An annular gap between a refractory lining of the furnace tank and the contact electrode assembly is tamped. For exchanging the contact electrode assembly, it is detached from the lining with the aid of pressure elements (telescoping cylinders) arranged below the furnace tank and lifted upward far enough for the contact electrode to be pulled out of the furnace tank by the grip of a pulling device. Then a new contact electrode assembly is inserted.

Description

Die Erfindung betrifft einen Gleichstrom-­Lichtbogen- oder Widerstands-Schmelzofen, insbesondere austauschbare Kontaktelektro­den-Anordnung, wobei die Kontaktelektrode aus einer metallischen Tragplatte besteht, ferner einer im Abstand davon angeordneten, mittels Bolzen mit der Tragplatte verbundenen metallischen Basisplatte, einem oder mehreren metallischen Kontaktstäben, die mit ihren Hälsen an der Basisplatte befestigt sind, einer feuerfesten Ausstampfung zwischen Oberkante Kontaktstäbe und Tragplatte und unterhalb der Basisplatte angeordneten Strom- und Kühlmittelleitungen.The invention relates to a direct-current arc or resistance melting furnace, in particular an exchangeable contact electrode arrangement, the contact electrode consisting of a metallic support plate, furthermore a metal base plate arranged at a distance therefrom and connected to the support plate by means of bolts, one or more metallic contact rods, which are attached with their necks to the base plate, a refractory stamping out between the upper edge of the contact rods and the support plate and power and coolant lines arranged below the base plate.

Beim Betrieb eines Wechselstrom-Lichtbogenofens treten Rückwirkungen auf das Stromversorgungs­netz auf in Form von Unsymmetrien und Flickern. Verschiedene Möglichkeiten zur Dämpfung dieser Erscheingungen sind bekannt, u.a. der Betrieb des Lichtbogenofens als Gleichstromofen. Durch die Fortschritte in der Entwicklung von Halbleiterbauelementen wurden in den letzten Jahren die Voraussetzungen geschaffen für den Bau entsprechender Gleichrichter.When operating an AC arc furnace, there are repercussions on the power supply network in the form of asymmetries and flickering. Various options for damping these vibrations are known, including the operation of the arc furnace as a direct current furnace. The advances in the development of semiconductor components have created the conditions for the construction of appropriate rectifiers in recent years.

Der Betrieb eines Lichtbogenofens als Gleich­stromofen mit einer kathodisch gepolten Graphit­elektrode und einer anodisch gepolten Kontakt­elektrode im Ofenboden bringt ferner den Vorteil erheblich verringerten Graphitelektrodenver­brauchs mit sich. Als weiterer Vorteil ist der deutlich geringere Geräuschpegel zu nennen.The operation of an arc furnace as a direct current furnace with a cathodically polarized graphite electrode and an anodically polarized contact electrode in the furnace base also has the advantage of significantly reduced graphite electrode consumption. Another advantage is the significantly lower noise level.

Aufbau und Wirkungsweise von Gleichstromlicht­bogenöfen sind aus mannigfachen Veröffentli­chungen bekannt. Das für den praktischen Ofen­betrieb wesentliche Bauteil ist die Kontakt­elektrode im Ofengefäß, die einerseits guten elektrischen Kontakt zum eingesetzten Schrott bzw. im späteren Verlauf des Schmelzvorgangs zum flüssigen Metall sicherstellen muß, andererseits aber hohen thermischen Belastungen ausgesetzt ist.The structure and mode of operation of direct current arc furnaces are known from numerous publications. The component that is essential for practical furnace operation is the contact electrode in the furnace vessel, which on the one hand must ensure good electrical contact with the scrap used or in the later course of the melting process with the liquid metal, but on the other hand is exposed to high thermal loads.

Eine derartige Kontaktelektrode ist bekannt aus der DE-PS 3l O6 74l.Such a contact electrode is known from DE-PS 3l O6 74l.

Die Kontaktelektroden im Gleichstrom-Lichtbogen­ofen unterliegen einem im Verhältnis zur Ofen­herdausmauerung voreilenden Verschleiß. Da das Auswechseln einzelner Kontaktstäbe einen relativ großen Arbeitsaufwand bedeutet, ist man in der Praxis dazu übergegangen, in entsprechenden Zeitabständen alle Kontaktstäbe gemeinsam auszuwechseln.The contact electrodes in the DC arc furnace are subject to premature wear in relation to the furnace hearth lining. Since the replacement of individual contact rods means a relatively large amount of work, in practice it has been decided to replace all the contact rods together at appropriate intervals.

In der bisher betriebenen Arbeitsweise wurde nach der letzten Schmelze eine geeignete Zugöse in die im Ofen behaltene geringe Restschmelze eingesetzt. Nach ihrer Erkaltung und Verfesti­gung können dann mittels einer geeigneten Vor­richtung die Restschmelze, Kontaktstäbe und Ausmauerung gezogen werden. Nach dem Ziehen werden neue Kontaktstäbe eingesetzt und das Zentrum des Ofenbodens neu gestampft.In the previous mode of operation, after the last melt, a suitable towing eye was inserted into the small residual melt kept in the furnace. After they have cooled and solidified, the residual melt, contact rods and lining can then be drawn using a suitable device. After pulling, new contact rods are inserted and the center of the furnace floor is stamped again.

Dieser Arbeitsweise haftet der Mangel an, daß das Einsetzen der Kontaktstäbe, das Stampfen des Zentrums des Ofenbodens sowie der daran anschließende Trocknungsvorgang der Stampfmasse die Wiederinbetriebnahme des Ofens verzögern. Ferner ist das Stampfen des Zentrums des Ofenbodens im Innern des heißen Ofens beschwerlich für das Personal.This mode of operation has the defect that the insertion of the contact rods, the tamping of the center of the furnace floor and the subsequent drying process of the ramming mass delay the restart of the furnace. Furthermore, tamping the center of the furnace floor inside the hot furnace is difficult for the personnel.

Aufgabe der Erfindung ist es, die Kontakt-Elek­trodenanordnung, wie sie nach der DE-PS 3l O6 74l vorgeschlagen wird, in Richtung auf eine einfachere und schnellere Herstellung, Montage und Demontage zu verbessern.The object of the invention is to improve the contact electrode arrangement, as proposed according to DE-PS 3l O6 74l, in the direction of simpler and faster production, assembly and disassembly.

Diese Aufgabe wird nach der Erfindung in der Weise gelöst, wie es in den Patentansprüchen im einzelnen angegeben ist.This object is achieved according to the invention in the manner as specified in the claims.

Die Kontaktelektroden-Anordnung wird demnach als komplettes Bauteil des Schmelzofens konzipiert und hergestellt. Das Einsetzen dieses Bauteils in das mit einer kreisförmigen Öffnung am Boden versehene Ofengefäß erfolgt mit Hilfe eines Krans. Zum Einheben werden an der Oberseite der Kontaktelektroden-Baueinheit Tragmittel (Ösen) eingelassen. Die Baueinheit wird in das Ofengefäß abgesenkt und setzt sich mit ihrer Tragplatte auf die ringförmige Versteifung im Ofengefäß auf. Die Basisplatte, an die die Strom- und Kühlmittelleitungen angeschlossen werden, hängt durch die Ofengefäßöffnung nach unten durch.The contact electrode arrangement is therefore designed and manufactured as a complete component of the melting furnace. This component is inserted into the furnace vessel with a circular opening on the bottom by means of a crane. For lifting purposes, suspension elements (eyelets) are inserted on the top of the contact electrode assembly. The assembly is lowered into the furnace vessel and sits on the ring-shaped stiffening in the furnace vessel with its support plate. The base plate to which the power and coolant lines are connected hangs down through the furnace opening.

Die erwähnten Tragmittel an der Oberseite der Kontaktelektroden-Baueinheit haben nach dem Absenken und Aufsetzen der Baueinheit auf den Ofengefäßboden ihre Aufgabe erfüllt und schmelzen bei Betrieb des Ofens ein.The suspension means mentioned on the top of the contact electrode assembly have done their job after lowering and placing the assembly on the bottom of the furnace vessel and melt during operation of the furnace.

Das Auswechseln der Kontaktelektroden-Bauein­heit, das nach entsprechendem Abbrand der Kon­taktstäbe erforderlich wird, geschieht in der Weise, wie es in den Verfahrensansprüchen ange­geben ist.The replacement of the contact electrode assembly, which becomes necessary after the contact rods have burned off appropriately, is carried out in the manner specified in the process claims.

Nachdem der Ofen leergefahren ist, werden die auf den Kragpratzen unterhalb des Ofengefäßes aufgelagerten Druckelemente (Teleskopzylinder) nach oben ausgefahren. Auf diese Weise wird zunächst mit einer großen Druckkraft die Kon­taktelektrode aus dem Ausstampfungsverbund herausgebrochen und anschließend so weit nach oben gedrückt, daß der Greifer eines oberhalb des geöffneten Ofengefäßes befindlichen Zugmittels die Kontaktelektrode umgreifen und nach oben aus dem Ofen herausziehen kann.After the furnace has been emptied, the pressure elements (telescopic cylinder) on the cantilever claws below the furnace vessel are extended. In this way, the contact electrode is first broken out of the pounding compound with a large compressive force and then pushed upwards so far that the gripper of a traction means located above the open furnace vessel can grip around the contact electrode and pull it up out of the furnace.

Ist dies geschehen, so wird eine neue Kontakt­elektroden-Baueinheit eingesetzt und der Ring­spalt zwischen der feuerfesten Ausmauerung des Ofengefäßes und der aufgelagerten Kontaktelektro­den-Baueinheit mit Feuerfestmaterial ausge­stampft.Once this has been done, a new contact electrode assembly is inserted and the annular gap between the refractory lining of the furnace vessel and the superimposed contact electrode assembly is filled with refractory material.

Alternativ kann das Auswechseln der Kontakt­elektroden-Baueinheit auch so vonstatten gehen, daß man nach der letzten Charge auf dem Herd­boden des Ofens noch eine Restschmelze beläßt und in diese Schmelze geeignete Tragösen ein­ setzt. Diese Ösen bekommen nach Erkalten der Schmelze ihren Halt. Nachdem nun mit Hilfe der Druckelemente (Teleskopzylinder) die Kontakt­elektrode lediglich aus dem Verbund im Ofenge­fäß herausgebrochen worden ist, haben die Trag­ösen ausreichenden Halt in der über der Kontakt­elektrode befindlichen Restschmelze, so daß von einem Zugmittel die aus dem Ofengefäß bereits herausgelöste Kontaktelektrode ohne Schwierig­keiten nach oben herausgezogen werden kann. An­schließend kann in bereits geschilderter Weise das Einsetzen einer neuen Kontaktelektroden-­Baueinheit stattfinden.Alternatively, the replacement of the contact electrode assembly can also be carried out in such a way that, after the last batch, a residual melt is left on the hearth of the furnace and suitable eyelets are inserted into this melt puts. These eyelets get their hold after the melt has cooled. Now that the contact electrode has only been broken out of the composite in the furnace vessel with the help of the pressure elements (telescopic cylinder), the support eyelets have sufficient hold in the residual melt located above the contact electrode, so that the contact electrode, which has already been released from the furnace vessel, can be lifted up without difficulty by a traction device can be pulled out. Subsequently, the insertion of a new contact electrode assembly can take place in the manner already described.

An Hand der schematischen Zeichnungen werden Einzelheiten der Erfindung nachstehend näher erläutert.Details of the invention are explained in more detail below with reference to the schematic drawings.

Es zeigen:

  • Fig. l einen Schnitt durch einen Gleichstrom-­Lichtbogenofen mit Kontaktelektroden-­Anordnung im Betriebszustand und
  • Fig. 2 einen Schnitt durch einen Ofen gemäß Fig. l, jedoch vor dem Wechsel der Kontaktelektroden-Anordnung.
Show it:
  • Fig. L shows a section through a direct current arc furnace with contact electrode arrangement in the operating state and
  • Fig. 2 shows a section through an oven according to FIG. 1, but before changing the contact electrode arrangement.

Das in den Figuren dargestellte Ofengefäß eines Gleichstrom-Lichtbogenofens besitzt einen Stahl­mantel l und einen stählernen Gefäßboden 7. Das Ofengefäß ist mit einer feuerfesten Ausmauerung 2 versehen.The furnace vessel of a direct current arc furnace shown in the figures has a steel jacket 1 and a steel vessel base 7. The furnace vessel is provided with a refractory lining 2.

Gemäß Fig. l ist in die kreisringförmige Boden­ausnehmung des Ofengefäßes die Kontaktelektrode als kompakte Baueinheit eingesetzt.According to FIG. 1, the contact electrode is inserted as a compact structural unit in the annular bottom recess of the furnace vessel.

Die Kontaktelektroden-Baueinheit wird außerhalb des Ofens komplett erstellt. Die Baueinheit be­steht aus einer Tragplatte 3, einer im Abstand darunter angeordneten, mittels Bolzen 5 mit der Tragplatte 3 verbundenen Basisplatte 4. Metallische Kontaktstäbe 6 sind senkrecht stehend mit ihren Hälsen an der Basisplatte 4 befestigt. Der Raum l3 der Kontaktelektrode von der Oberkante der Kontaktstäbe 6 bis hin zur Tragplatte 3 wird in der Weise ausgestampft, daß um die Kontaktelektrode eine Schablone angeordnet wird, die nach der Verfestigung der Ausstampfung wieder entfernt wird.The contact electrode assembly is completely created outside the furnace. The structural unit consists of a support plate 3, a base plate 4 arranged at a distance below it and connected to the support plate 3 by means of bolts 5. The space l3 of the contact electrode from the upper edge of the contact rods 6 to the support plate 3 is stamped out in such a way that a template is arranged around the contact electrode, which is removed again after the stamping out has solidified.

Die Kontaktelektroden-Baueinheit erhält an ihrer Oberseite mindestens ein Tragmittel (Tragöse), an das Haken des Zugmittels angeschlagen werden, mit dem die komplette Kontaktelektroden-Bauein­heit von oben in das Ofengefäß abgesenkt wird. Die Kontaktelektrode wird mit ihrer Tragplatte 3 auf dem Rand der kreisringförmigen Bodenausneh­mung abgesetzt und durch geeignete Mittel mit dem Ofengefäß verbunden.The upper side of the contact electrode assembly has at least one suspension element (lifting eye), against which the hook of the traction mechanism is attached, with which the entire contact electrode assembly is lowered into the furnace vessel from above. The contact electrode is placed with its support plate 3 on the edge of the annular bottom recess and connected to the furnace vessel by suitable means.

Ist die Kontaktelektroden-Baueinheit eingesetzt, so wird der Ringspalt ll zwischen der einge­setzten Bauenheit und der feuerfesten Ausmaue­rung 2 des Ofengefäßes l mit Feuerfestmaterial ausgestampft. Die erwähnten, nicht dargestell­ten Tragmittel (Tragösen) schmelzen beim ersten Ofenbetrieb ab.If the contact electrode assembly is used, the annular gap 11 between the construction used and the refractory lining 2 of the furnace vessel 1 is stamped out with refractory material. The suspension means (lifting eyes), not shown, melt during the first furnace operation.

Das Auswechseln der verbrauchten Kontaktelek­trode geschieht in der Weise, daß nach dem Leerfahren des Ofens die sich auf den Krag­pratzen 9 der sich unterhalb des Ofengefäßes erstreckenden ringförmigen Versteifung 8 be­findlichen Druckelemente (Teleskopzylinder lO) nach oben ausgefahren werden und die komplette Kontaktelektroden-Baueinheit aus dem Aus­stampfungsverbund mit dem Ofengefäß heraus­gebrochen wird. Sobald das Herausbrechen erfolgt ist, können die Teleskopzylinder lO weiter aus­gefahren werden, so daß die Kontaktelektrode so weit aus dem Herdboden des Ofengefäßes hervor­tritt, daß sie von dem Greifer eines nicht dar­gestellten, oberhalb des geöffneten Ofens be­findlichen Krans umgriffen und herausgezogen werden kann.The exchange of the used contact electrode takes place in such a way that after the furnace has been emptied, the pressure elements (telescopic cylinder 10) located on the cantilever claws 9 of the annular stiffening 8 extending below the furnace vessel are extended and the complete contact electrode assembly is removed from the stamping compound is broken out with the furnace vessel. As soon as the break-out has taken place, the telescopic cylinders 10 can be extended further so that the contact electrode emerges from the hearth of the furnace vessel to such an extent that it can be gripped and pulled out by the gripper of a crane (not shown) located above the open furnace.

Eine Alternative des Auswechselns der Kontakt­elektroden-Baueinheit sieht vor, daß nach der letzten Ofencharge im Herdboden noch eine Rest­schmelze l7 belassen wird. In diese Restschmelze l7 wird mindestens eine Tragöse l4 eingelassen, an die nach dem Erkalten der Restschmelze l7 ein Zugmittel angeschlagen wird, das die Kontakt­elektroden-Baueinheit aus dem Ofengefäß nach oben herauszieht, nachdem zuvor die Kontakt­elektrode mit Hilfe der unterhalb des Ofenge­fäßes angeordneten Druckelemente lO (Teleskop­zylinder) aus dem Verband mit dem Ofengefäß durch Hochfahren der Teleskopzylinder heraus­gebrochen worden ist.An alternative to replacing the contact electrode assembly provides that a residual melt 17 is left in the hearth floor after the last batch of the furnace. At least one support eyelet l4 is let into this residual melt l7, to which, after the residual melt l7 has cooled, a traction means is struck, which pulls the contact electrode assembly upward out of the furnace vessel after the contact electrode has previously been arranged with the aid of the pressure elements lO (below the furnace vessel ( Telescopic cylinder) has been broken out of the association with the furnace vessel by raising the telescopic cylinder.

Liste der Bezugsziffern:List of reference numbers:

  • l Ofengefäßmantell furnace jacket
  • 2 Ofengefäß-Ausmauerung2 furnace lining
  • 3 Tragplatte3 support plate
  • 4 Basisplatte4 base plate
  • 5 Verbindungsbolzen Tragplatte - Basisplatte5 connecting bolts support plate - base plate
  • 6 Kontaktstäbe6 contact rods
  • 7 Ofengefäßboden7 furnace bottom
  • 8 Ringförmige Aussteifung des Ofengefäßbodens 78 Ring-shaped stiffening of the furnace bottom 7
  • 9 Kragpratzen9 claws
  • lO Druckelemente (Teleskopzylinder)lO pressure elements (telescopic cylinder)
  • ll Ringspalt zwischen Ofenausmauerung 2 und Kontaktelektroden-Anordnungll Annular gap between furnace lining 2 and contact electrode arrangement
  • l2 Strom- und Kühlmittelleitungenl2 power and coolant lines
  • l3 Ausstampfung der Kontaktelektroden-Anordnungl3 stamping out of the contact electrode arrangement
  • l4 Tragösen zum Herausziehen der Kontaktelek­troden-Anordnungl4 lifting eyes for pulling out the contact electrode arrangement
  • l5 Schmelzelektrodel5 fusible electrode
  • l6 Ofendeckell6 furnace lid
  • l7 Restschmelzel7 residual melt

Claims (5)

1. Gleichstrom-Lichtbogen- oder Widerstands-­Schmelzofen, insbesondere austauschbare Kontaktelektroden-Anordnung, wobei die Kontaktelektrode aus einer metallischen Trag­platte besteht, ferner einer im Abstand davon angeordneten, mittels Bolzen mit der Trag­platte verbundenen metallischen Basisplatte, einem oder mehreren metallischen Kontakt­stäben, die mit ihren Hälsen an der Basis­platte befestigt sind, einer feuerfesten Aus­stampfung zwischen Oberkante Kontaktstäbe und Tragplatte und unterhalb der Basisplatte ange­ordneten Strom- und Kühlmittelleitungen,
dadurch gekennzeichnet,
daß die Kontaktelektroden-Anordnung als aus­tauschbare Baueinheit (3, 4, 5, 6, l2, l3) außerhalb des Ofens (l) hergestellt, mittels Schablone ausgestampft, getrocknet bzw. ge­sintert ist, der Ofengefäßboden (7) eine Öffnung zur Auflagerung der Kontaktelektroden-­Anordnung aufweist, daß die Ofengefäßbodenöff­nung eine nach unten sich erstreckende ring­förmige Versteifung (8) mit eingebauten Krag­pratzen (9) besitzt, auf die Druckelemente (lO) aufgelagert sind.1. DC arc or resistance melting furnace, in particular interchangeable contact electrode arrangement, wherein the contact electrode consists of a metallic support plate, further a metal base plate arranged at a distance therefrom, connected to the support plate by means of bolts, one or more metallic contact rods, which are connected to their necks are fastened to the base plate, a refractory stamping out between the upper edge of the contact rods and the support plate and power and coolant lines arranged below the base plate,
characterized,
that the contact electrode arrangement is made as an interchangeable unit (3, 4, 5, 6, l2, l3) outside the furnace (l), stamped out, dried or sintered by means of a template, the furnace vessel bottom (7) has an opening for supporting the contact electrodes Arrangement has that the furnace bottom opening has a downwardly extending annular stiffener (8) with built-in claws (9) on which pressure elements (10) are supported. 2. Gleichstrom-Lichtbogen- oder Widerstands-­Schmelzofen nach Anspruch l,
dadurch gekennzeichnet,
daß die Kontaktelektroden-Baueinheit (3, 4, 5, 6, l2, l3) an ihrer Oberseite mindestens ein Tragmittel besitzt.2. DC arc or resistance melting furnace according to claim l,
characterized,
that the contact electrode assembly (3, 4, 5, 6, l2, l3) has at least one suspension element on its upper side. 3. Gleichstrom-Lichtbogen- oder Widerstands-­Schmelzofen nach Anspruch l,
dadurch gekennzeichnet,
daß der Ringspalt (ll) zwischen der in die Ofengefäßbodenöffnung eingesetzten Kontakt­elektroden-Baueinheit (3, 4, 5, 6, l2, l3) und der feuerfesten Ausmauerung (2) des Ofen­gefäßes (l) ausgestampft ist.3. DC arc or resistance melting furnace according to claim l,
characterized,
that the annular gap (II) between the contact electrode assembly (3, 4, 5, 6, l2, l3) inserted in the furnace vessel bottom opening and the refractory lining (2) of the furnace vessel (l) is stamped out. 4. Verfahren zum Auswechseln der Kontaktelektro­den-Baueinheit eines Gleichstrom-Lichtbogen- ­oder Widerstands-Schmelzofens nach den An­sprüchen l bis 3,
dadurch gekennzeichnet,
daß die Kontaktelektroden-Baueinheit (3, 4, 5, 6, l2, l3) mittels auf den Kragpratzen (9) der ringförmigen Ofengefäßbodenversteifung (8) aufgelagerter Druckelemente (lO) aus der Ausmauerung (2) gelöst und angehoben wird und von einem Greifer eines Zugmittels nach oben herausgezogen wird, und daß die neue Kontakt­elektroden-Baueinheit an einem Tragmittel von oben in das Ofengefäß eingesetzt wird.4. A method for replacing the contact electrode assembly of a direct current arc or resistance melting furnace according to claims 1 to 3,
characterized,
that the contact electrode assembly (3, 4, 5, 6, l2, l3) is released from the lining (2) and lifted by a gripper by means of pressure elements (10) supported on the cantilever claws (9) of the annular furnace bottom reinforcement (8) a pulling means is pulled out upwards, and that the new contact electrode assembly is inserted into a support means from above into the furnace vessel. 5. Verfahren zum Auswechseln der Kontaktelek­troden-Baueinheit eines Gleichstrom-Licht­bogen- oder Widerstands-Schmelzofens nach den Ansprüchen l bis 3,
dadurch gekennzeichnet,
daß Tragösen (l4) in die Restschmelze (l7) des Ofens eingesetzt werden, die Kontakt­elektroden-Baueinheit (3, 4, 5, 6, l2, l3) mittels auf den Kragpratzen (9) der ring­förmigen Ofengefäßbodenversteifung (8) auf­gelagerter Druckelemente (lO) aus der Aus­mauerung (2) gelöst und angehoben wird und nach Erkalten der Restschmelze (l7) die Kontaktelektroden-Baueinheit (3, 4, 5, 6, l2, l3) nach oben herausgezogen wird, und daß die neue Kontaktelektroden-Baueinheit an einem Tragmittel von oben in das Ofengefäß einge­setzt wird.5. A method for replacing the contact electrode assembly of a direct current arc or resistance melting furnace according to claims 1 to 3,
characterized,
that lifting eyes (l4) are inserted into the residual melt (l7) of the furnace, the contact electrode assembly (3, 4, 5, 6, l2, l3) by means of pressure elements (lO ) is removed from the lining (2) and raised and after cooling the residual melt (l7) the contact electrode assembly (3, 4, 5, 6, l2, l3) is pulled out upwards, and that the new contact electrode assembly at one Suspension means is inserted into the furnace vessel from above.
EP86111685A 1985-10-05 1986-08-22 Arrangement of contact electrodes for direct-current arc furnaces or resistance-melting furnaces Expired - Lifetime EP0219650B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86111685T ATE62577T1 (en) 1985-10-05 1986-08-22 CONTACT ELECTRODE ARRANGEMENT FOR DC ARC OR RESISTANCE MELTING FURNACES.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19853535692 DE3535692A1 (en) 1985-10-05 1985-10-05 CONTACT ELECTRODE ARRANGEMENT FOR DC ARC OR RESISTANCE MELTING OVENS
DE3535692 1985-10-05

Publications (2)

Publication Number Publication Date
EP0219650A1 true EP0219650A1 (en) 1987-04-29
EP0219650B1 EP0219650B1 (en) 1991-04-10

Family

ID=6282922

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EP86111685A Expired - Lifetime EP0219650B1 (en) 1985-10-05 1986-08-22 Arrangement of contact electrodes for direct-current arc furnaces or resistance-melting furnaces

Country Status (5)

Country Link
US (1) US4700355A (en)
EP (1) EP0219650B1 (en)
JP (1) JPS6282694A (en)
AT (1) ATE62577T1 (en)
DE (2) DE3535692A1 (en)

Cited By (2)

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Publication number Priority date Publication date Assignee Title
DE4222854A1 (en) * 1992-07-11 1994-01-13 Gutehoffnungshuette Man Base electrode for direct current arc furnaces - with metal rods arranged in hearth base, with non-conducting refractory layers surrounding the rods
US5371759A (en) * 1991-09-12 1994-12-06 Kortec Ag D.C. furnace with a hearth electrode, hearth electrode and electrode block, as well as process for operating said furnace

Families Citing this family (5)

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JPH01128392A (en) * 1987-11-12 1989-05-22 Nkk Corp Electrode block for d.c. electric furnace
JPH0624157Y2 (en) * 1988-07-01 1994-06-22 日本鋼管株式会社 Bottom electrode of DC electric furnace
DE4022720A1 (en) * 1990-07-17 1992-01-23 Flohe Gmbh & Co UNDERWAY OF A DC ARC FURNACE
US5280495A (en) * 1992-02-14 1994-01-18 Ajax Magnethermic Corporation Furnace refractory extraction system and method
DE19921287A1 (en) * 1999-05-07 2000-11-16 Sms Demag Ag DC oven

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FR1557843A (en) * 1967-01-02 1969-02-21
GB2055028A (en) * 1979-06-26 1981-02-18 Asea Ab Hearth connection for a d c arc furnace
EP0133931A1 (en) * 1983-07-28 1985-03-13 BBC Brown Boveri AG Cooling arrangement of a bottom electrode of a direct current arc furnace
EP0133925A1 (en) * 1983-07-28 1985-03-13 BBC Aktiengesellschaft Brown, Boveri & Cie. Bottom electrode arrangement for a direct current arc furnace
EP0156126A2 (en) * 1984-03-14 1985-10-02 MAN Gutehoffnungshütte Aktiengesellschaft Hearth, in particular for a DC arc furnace

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5371759A (en) * 1991-09-12 1994-12-06 Kortec Ag D.C. furnace with a hearth electrode, hearth electrode and electrode block, as well as process for operating said furnace
DE4222854A1 (en) * 1992-07-11 1994-01-13 Gutehoffnungshuette Man Base electrode for direct current arc furnaces - with metal rods arranged in hearth base, with non-conducting refractory layers surrounding the rods

Also Published As

Publication number Publication date
US4700355A (en) 1987-10-13
EP0219650B1 (en) 1991-04-10
ATE62577T1 (en) 1991-04-15
DE3535692A1 (en) 1987-04-09
JPH0464155B2 (en) 1992-10-14
JPS6282694A (en) 1987-04-16
DE3678666D1 (en) 1991-05-16

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