EP2853610A2 - Device and method for electro-slag remelting - Google Patents

Device and method for electro-slag remelting Download PDF

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Publication number
EP2853610A2
EP2853610A2 EP20140186604 EP14186604A EP2853610A2 EP 2853610 A2 EP2853610 A2 EP 2853610A2 EP 20140186604 EP20140186604 EP 20140186604 EP 14186604 A EP14186604 A EP 14186604A EP 2853610 A2 EP2853610 A2 EP 2853610A2
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EP
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Prior art keywords
preheating
tip
fuel
abschmelzelektrode
furnace
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EP20140186604
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German (de)
French (fr)
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EP2853610B1 (en
EP2853610A3 (en
Inventor
Michael Potesser
Johannes Rauch
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Messer Austria GmbH
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Messer Austria GmbH
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Priority to SI201430578T priority Critical patent/SI2853610T1/en
Priority to RS20180087A priority patent/RS56789B1/en
Priority to PL14186604T priority patent/PL2853610T3/en
Publication of EP2853610A2 publication Critical patent/EP2853610A2/en
Publication of EP2853610A3 publication Critical patent/EP2853610A3/en
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Publication of EP2853610B1 publication Critical patent/EP2853610B1/en
Priority to HRP20180138TT priority patent/HRP20180138T1/en
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    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/16Remelting metals
    • C22B9/18Electroslag remelting

Definitions

  • the invention relates to an apparatus for producing metal blocks by the electroslag remelting process, comprising a metallurgically active slag bath and a preheating oven for preheating at least one tip of a consumable electrode to be supplied to the slag bath.
  • the invention further relates to a corresponding method.
  • meltdown electrodes dip into a resistance heated, metallurgically active slag bath located within a mold, usually cooled by water.
  • the slag overheats (1700 ° C to 2000 ° C) and metal drops melt from the Abschmelzelektrode.
  • the droplets sink through the slag, where they are freed from non-metallic contaminants by chemical extraction, and are finally collected in the still-liquid, already refined steel bath.
  • the quality of the finished ESU block depends not only on the quality of the consumable electrodes and the accuracy of the system control, but above all on the quality of the slag used.
  • Pre-molten slags provide a safe starting point. They ensure a reliable composition with good homogeneity for a uniform and reproducible process management in remelting operation.
  • the ESU process is now usually held under inert gas, such as in the DE 101 28 168 C1 or the EP 0 727 500 B1 described.
  • a plurality of melting electrodes are successively melted, with one electrode removed during the ESC process apart from the remainder being removed from the slag bath and replaced by a new melting electrode.
  • the alternating electrodes are preheated before they are fed to the slag bath, while the previously used electrode is still in contact with the slag bath Melting process, wherein at least the region (hereinafter referred to as "tip") is preheated the Abschmelzelektrode, which is later immersed in the slag bath.
  • tip region
  • An approach of this kind is, for example, in the DE 2 124 960 A2 described.
  • the preheating of the Abschmelzelektrode for remelting in an ESU plant is nowadays usually with current-heated Vormérmöfen, which are arranged spaced from the remelting furnace.
  • Vormérmöfen which are arranged spaced from the remelting furnace.
  • an ESU apparatus is known in which the tip of an alternating electrode is preheated by means of an inductor and then fed to the reflow.
  • heating takes place between 300 ° C. and 900 ° C.
  • the known ESU systems with electric preheating are associated with a number of disadvantages.
  • the efficiency of these furnaces is very low, which is reflected in the achievable, far below the respective melting temperatures preheating temperatures, high power consumption and lower product quality;
  • Last but not least, a low product quality is also due to the high duration of time required for the electrode change between the removal of the old electrode and the heating of the new electrode to the melting point.
  • the heated by means of electrical resistance Vorissermöfen are very maintenance-intensive, which manifests itself in high maintenance costs and frequent shutdowns.
  • the invention is therefore based on the object to improve the efficiency of working with alternating electrodes ESU system and to reduce maintenance.
  • the method according to the invention is characterized in that the preheating of the tip of the consumable electrode in the preheating furnace by combustion of a Fuel with an oxidizer takes place.
  • the preheating furnace is operated in the manner of a cyclone furnace, ie fuel and / or oxidizer are registered with a - viewed in a plane perpendicular to the longitudinal axis of the preheating furnace - tangential direction component in the combustion region of the furnace. This results in a swirling flow in which fuel and oxidant are conducted past the tip of the preheating electrode to be preheated.
  • the tip of the Abschmelzelektrode can thus be heated to a temperature which is close to the melting temperature of the material to be remelted in each case;
  • the interruption duration of the remelting process during the electrode change that is to say the time duration between the termination of the melting process of the old and the beginning of the melting process of the new electrode, is significantly shortened.
  • fuels are gaseous fuels, such as natural gas, as well as aerosol atomized liquid fuels or fluidized solid particles (dusts).
  • fuels may be used which contain carbon, hydrogen, sulfur or a mixture of two or three of these substances or a compound containing one or more of these substances.
  • the oxidizing agent used can be air or an oxygen-enriched gas (with an oxygen content of more than 21% by volume); Pure oxygen is preferably suitable with an oxygen concentration of more than 90% by volume, particularly preferably with an oxygen concentration of more than 95% by volume.
  • the insertion means are either perpendicular to the longitudinal axis of the preheating furnace or arranged, or angular, with its mouth opening facing upwards, ie in the direction of the preheating Abschmelzelektrode to favor the formation of a helical flow.
  • a direct loading of the Abschmelzelektrode should be avoided with a burner flame, as this can lead to a local overheating of Abschmelzelektrode.
  • an arrangement of lances can be provided as insertion devices, by means of which the fuel and oxidizer are introduced at respectively separate locations into the combustion region, subsequently mixed and ignited.
  • a plurality of tangentially carrying lances or burners are arranged at preferably uniform angular intervals in order to ensure uniform heating of the electrode surface.
  • the entry device or the entry devices are arranged in their length and / or angular position adjustable in the wall of the preheating furnace.
  • the position of the entry device can be adapted in this way the geometry of the respective preheating electrode.
  • it is also conceivable within the scope of the invention to change the position of the insertion device relative to the electrode during the current warm-up process in order to achieve optimal heat application with minimum energy input for example the electrode can be opposite the preheating furnace or opposite the electrode about its longitudinal axis be rotatably mounted to allow even with a small number of entry devices in the preheating a uniform heat application of the electrode tip.
  • the end portion of the preheating furnace is equipped with a cover which is intended to prevent the ingress of ambient atmosphere.
  • a cover which is intended to prevent the ingress of ambient atmosphere.
  • the cover In the case of long melting electrodes, it is advisable in this case to equip the cover with a recess for the electrode, so that in operation the melting electrode protrudes only with its tip into the combustion region enclosed by the cover.
  • the cover At this Embodiment of the invention, therefore, only the area of the electrode tip is intensively charged with hot combustion gases, wherein the cover at least largely prevents gases from the ambient atmosphere, in particular oxygen, penetrate into the heated region of the preheating furnace and lead to undesirable reactions on the surface of the electrode.
  • a hood which completely envelopes the electrode for example a hood construction of the type as described in US Pat EP 0 727 500 B1 is described.
  • the preheating furnace is equipped with an exhaust system for controlling the furnace pressure.
  • the exhaust system includes, for example, means for controlling the pressure or the composition of the atmosphere in the furnace chamber, such as a suction device or means for recirculation of flue gases.
  • the inventive method for producing metal blocks after the electroslag remelting of metals in which a Abschmelzelektrode preheated and then lowered at least with its tip in a metallurgical slag bath, is characterized in that the preheating of the Abschmelzelektrode prior to their supply to the slag by means of Applying at least the tip of the Abschmelzelektrode with a mutually reactive fuel-oxidizer mixture takes place.
  • a particularly preferred embodiment of the method according to the invention provides for the preheating of the tip of the consumable electrode to take place by forming a flame cyclone enveloping the tip.
  • a flame cyclone is created by a tangential entry of fuel and / or oxidizer by means of lances or burners.
  • the substances which react with each other are guided around the tip of the consumable electrode in a swirling flow and heat them up uniformly and with the risk of local overheating being largely eliminated.
  • the duration of the electrode change has a significant influence on the crystallization process and thus the quality of the metal block produced by ESC.
  • at least the tip of the Abschmelzelektrode is heated to a temperature between 100 ° C and the melting temperature of the material of each Abschwezelektrode preh Securenden, preferably between 900 ° C and 1400 ° C.
  • An advantageous development of the invention provides a control by means of which the ratio of fuel and oxidant of the burner during the preheating process can be changed. In this way, the firing in the preheating furnace can be optimized and, in particular, the temperature of the burner flame can be precisely set. Likewise, it is also possible to change or regulate the oxygen content in the oxidizer used during the operation of the preheating furnace by means of the controller.
  • a further preferred embodiment of the invention is characterized in that measures are taken that allow a recirculation of fuel gases in the area before the exit of the burner or the outlet of the burner and thereby flameless - and thus particularly low-emission and energy-efficient - combustion takes place.
  • FIG. 1 shows schematically the construction of a preheating furnace according to the invention for an ESU plant in longitudinal section.
  • the preheating furnace 1 shown in Fig. 1 comprises a constructed of refractory material furnace shell 2, the downwardly facing end portion 3 is conically formed.
  • the end portion 3 are in the wall of the furnace shell 2 bushings 7th 8, in which a plurality of burners are arranged at regular angular intervals, in the exemplary embodiment two burners 9, 10.
  • the burners 9, 10 are burners in the exemplary embodiment shown, by means of which a gaseous fuel, for example natural gas, and oxygen in the Combustion area 6 registered and burned there; However, within the scope of the invention, other burners may also be used, such as burners operating with a solid or liquid fuel and / or burners employing air, oxygen-enriched air or a gas having an oxygen content variable during operation as the oxidizer ,
  • the burners 9, 10 protrude tangentially into the preheating furnace 1 and are arranged in an axial direction with respect to a plane perpendicular to the longitudinal axis of the preheating furnace 1 at an angle, each with its mouth openings facing upward.
  • a further passage 11 is arranged, in which an exhaust pipe 12 is installed for discharging the flue gas.
  • a preheating electrode 13 is guided with its tip 14 through the opening 5 of the cover plate 4 and positioned so that the tip 14 is arranged in the region of the end portion 3, but without touching the walls of the furnace shell 2.
  • the cover plate 4 may be made in two parts and only after the positioning of the Abschmelzelektrode 13 from both sides substantially gas-tightly applied to this.
  • the central opening 5 of the cover plate 4 is adapted to the outer diameter of the Abschmelzelektrode 13 and ideally allows no, usually only a small gas exchange between the combustion region 6 and the ambient atmosphere.
  • the positioning of the Abschmelzelektrode 13 is effected for example by means of a crane assembly 15, which also allows the vertical process of Abschmelzelektrode 13 in the preheating furnace 1 in and out of this.
  • Fuel or oxygen is fed to the burners 9, 10 via a fuel feed line 16 and an oxygen feed line 17, and the fuel-oxidant mixture forming in each case before the outlets of the burners 9, 10 is ignited.
  • the entry of the fuel-oxidizer mixture is in each case tangentially into the combustion zone, wherein the axial tendency of the burner 9, 10 in the direction of the tip 14 of the Abschmelzelektrode 13 and the conical shaping of the end portion 3 a total of a helical course of the flow cause in the combustion region 6.
  • a flame cyclone which wraps the tip 14 of the Abschmelzelektrode 13 while heated uniformly and to a temperature near the melting temperature of the material of the Abschmelzelektrode 13, for example to a value between 900 ° C and 1400 ° C, brought.
  • the temperature can be adjusted or regulated by means of a control, not shown here, which controls the inflows of fuel and / or oxidant.
  • the burners 9, 10 are angularly and / or length-adjustable accommodated in the furnace shell 2.
  • the resulting during combustion flue gases are withdrawn via the exhaust pipe 12.
  • a suction device 18 arranged in the exhaust pipe 12 makes it possible to regulate or adjust the pressure in the combustion region 6.
  • the burners 9, 10 are designed so that it comes within the combustion region 6 to a flameless combustion and thus to a uniform heating of the tip 14 of the Abschmelzelektrode 13 at the same time reduced pollutant emissions.
  • the tip 14 of the Abschmelzelektrode 13 After the tip 14 of the Abschmelzelektrode 13 has been heated to a predetermined temperature value, the supply of fuel and oxygen via the supply lines 16, 17 is blocked.
  • the Abschmelzelektrode 13 is from the Preheating furnace 13 withdrawn and fed to the mold of an electrode slag remelting furnace, not shown here.
  • the preheating furnace 1 is then available for receiving a further Abschmelzelektrode available.
  • the preheating furnace according to the invention operated by combustion of a fuel, the preheating of melting electrodes can be operated much more economically and at higher temperatures than is the case with conventional, electrically operated preheating furnaces.

Abstract

Eine Vorrichtung zum Elektroschlacke-Umschmelzen von Metallen, umfasst einen Vorwärmofen (1) zum Vorwärmen einer selbstverzehrende Abschmelzelektrode (13) vor ihrer Zuführung an ein Schlackenbad und ist erfindungsgemäß dadurch gekennzeichnet, dass der Vorwärmofen (1) mit wenigstens einem Brenner (9, 10) ausgerüstet ist, mittels dem die Vorwärmung der Abschmelzelektrode (13) durch Verbrennung eines Brennstoffs mit einem Oxidator erfolgt. Bei der Vorwärmung wird zumindest die Spitze (14) der Abschmelzelektrode (13) in den Vorwärmofen (1) eingeführt und durch Kontaktieren mit einem miteinander reagierenden Brennstoff-Oxidator-Gemisches beheizt. Bevorzugt wird bei der Beheizung dabei ein Flammen-Zyklon erzeugt, der eine gleichmäßige Erwärmung der Spitze (14) der ermöglicht.

Figure imgaf001
A device for electroslag remelting of metals, comprising a preheating furnace (1) for preheating a self-consumable Abschmelzelektrode (13) before being fed to a slag bath and is inventively characterized in that the preheating furnace (1) with at least one burner (9, 10) is equipped, by means of which the preheating of the Abschmelzelektrode (13) takes place by combustion of a fuel with an oxidizer. During preheating, at least the tip (14) of the ablation electrode (13) is introduced into the preheating furnace (1) and heated by contacting with a mutually reactive fuel-oxidizer mixture. In the case of heating, a flame cyclone is preferably produced in this process, which enables a uniform heating of the tip (14).
Figure imgaf001

Description

Die Erfindung betrifft eine Vorrichtung zum Herstellen von Metallblöcken nach dem Elektroschlacke-Umschmelzverfahren, mit einem metallurgisch wirksamen Schlackenbad und einem Vorwärmofen zum Vorwärmen von zumindest einer Spitze einer dem Schlackenbad zuzuführenden Abschmelzelektrode. Die Erfindung betrifft des Weiteren ein entsprechendes Verfahren.The invention relates to an apparatus for producing metal blocks by the electroslag remelting process, comprising a metallurgically active slag bath and a preheating oven for preheating at least one tip of a consumable electrode to be supplied to the slag bath. The invention further relates to a corresponding method.

Beim Elektroschlacke-Umschmelzen (ESU) tauchen selbstverzehrende Abschmelzelektroden in ein widerstandsbeheiztes, metallurgisch wirksames Schlackenbad, das sich innerhalb einer üblicherweise mittels Wasser gekühlten Kokille befindet. Die Schlacke überhitzt (1700°C bis 2000°C) und Metalltropfen schmelzen von der Abschmelzelektrode ab. Die Tröpfchen sinken durch die Schlacke, in der sie durch chemische Extraktion von nichtmetallischen Verunreinigungen befreit werden, und werden schließlich im noch flüssigen, bereits raffinierten Stahlbad aufgefangen. Dort erfolgt eine dichte und gerichtete Erstarrung des aufgeschmolzenen Metalls von unten nach oben. Die Qualität des fertigen ESU-Blockes hängt neben der Abschmelzelektrodenqualität und der Genauigkeit der Anlagensteuerung vor allem von der Qualität der eingesetzten Schlacke ab. Vorgeschmolzene Schlacken bieten dabei eine sichere Ausgangsbasis. Sie gewährleisten eine zuverlässige Zusammensetzung mit guter Homogenität für eine gleichmäßige und reproduzierbare Prozessführung im Umschmelzbetrieb. Um negative Einflüsse der Umgebungsluft auf die Schlacke und die Metallschmelze zu unterbinden, findet das ESU-Verfahren heute üblicherweise unter Schutzgas statt, wie beispielsweise in der DE 101 28 168 C1 oder der EP 0 727 500 B1 beschrieben.In electroslag remelting (ESC), self-depleting meltdown electrodes dip into a resistance heated, metallurgically active slag bath located within a mold, usually cooled by water. The slag overheats (1700 ° C to 2000 ° C) and metal drops melt from the Abschmelzelektrode. The droplets sink through the slag, where they are freed from non-metallic contaminants by chemical extraction, and are finally collected in the still-liquid, already refined steel bath. There is a dense and directed solidification of the molten metal from bottom to top. The quality of the finished ESU block depends not only on the quality of the consumable electrodes and the accuracy of the system control, but above all on the quality of the slag used. Pre-molten slags provide a safe starting point. They ensure a reliable composition with good homogeneity for a uniform and reproducible process management in remelting operation. In order to prevent negative influences of the ambient air on the slag and the molten metal, the ESU process is now usually held under inert gas, such as in the DE 101 28 168 C1 or the EP 0 727 500 B1 described.

Zur Herstellung größerer Metallblöcke werden nacheinander mehrere Abschmelzelektroden abgeschmolzen, wobei jeweils eine während des ESU-Verfahrens bis auf einen Rest abgeschmolzene Elektrode aus dem Schlackenbad entfernt und durch eine neue Abschmelzelektrode ersetzt wird. Um die dabei auftretende Unterbrechung des Schmelzvorgangs so gering wie möglich zu halten, werden die Wechselelektroden vor ihrer Zuführung an das Schlackenbad vorgewärmt, noch während sich die zuvor verwendete Elektrode im Abschmelzvorgang befindet, wobei zumindest der Bereich (hier in Folgenden "Spitze" genannt) der Abschmelzelektrode vorgewärmt wird, der später in das Schlackenbad eingetaucht wird. Eine Vorgehensweise dieser Art wird beispielsweise in der DE 2 124 960 A2 beschrieben. Die Vorwärmung der Abschmelzelektrode zum Umschmelzen in einer ESU-Anlage erfolgt heute üblicherweise mit strombeheizten Vorwärmöfen, die vom Umschmelzofen beabstandet angeordnet sind. Beispielsweise ist aus der DE 2 755 478 A1 eine ESU-Apparatur bekannt, bei der die Spitze einer Wechselelektrode mit Hilfe eines Induktors vorgewärmt und anschließend der Aufschmelzung zugeführt wird. Bei den heute eingesetzten elektrischen Vorwärmofen erfolgt dabei eine Aufheizung zwischen 300°C und 900°C.To produce larger metal blocks, a plurality of melting electrodes are successively melted, with one electrode removed during the ESC process apart from the remainder being removed from the slag bath and replaced by a new melting electrode. In order to keep the interruption of the melting process as low as possible, the alternating electrodes are preheated before they are fed to the slag bath, while the previously used electrode is still in contact with the slag bath Melting process, wherein at least the region (hereinafter referred to as "tip") is preheated the Abschmelzelektrode, which is later immersed in the slag bath. An approach of this kind is, for example, in the DE 2 124 960 A2 described. The preheating of the Abschmelzelektrode for remelting in an ESU plant is nowadays usually with current-heated Vorwärmöfen, which are arranged spaced from the remelting furnace. For example, is from the DE 2 755 478 A1 an ESU apparatus is known in which the tip of an alternating electrode is preheated by means of an inductor and then fed to the reflow. In the case of the electric preheating furnace used today, heating takes place between 300 ° C. and 900 ° C.

Die bekannten ESU- Anlagen mit elektrischer Vorwärmung sind mit einer Reihe von Nachteilen verknüpft. Einerseits ist der Wirkungsgrad dieser Öfen sehr gering, welches sich in den erreichbaren, weit unter den jeweiligen Schmelztemperaturen liegenden Vorwärmtemperaturen, hohen Stromverbräuchen und niedrigerer Produktqualität wiederspiegelt; nicht zuletzt ist eine niedrige Produktqualität einer auch der hohen Zeitdauer geschuldet, die beim Elektrodenwechsel zwischen der Entfernung der alten und der Aufheizung der neuen Elektrode auf Schmelztemperatur erforderlich ist. Zudem sind die mittels elektrischem Widerstand beheizten Vorwärmöfen sehr wartungsintensiv, welches sich in hohen Wartungskosten und häufigen Stillständen manifestiert.The known ESU systems with electric preheating are associated with a number of disadvantages. On the one hand, the efficiency of these furnaces is very low, which is reflected in the achievable, far below the respective melting temperatures preheating temperatures, high power consumption and lower product quality; Last but not least, a low product quality is also due to the high duration of time required for the electrode change between the removal of the old electrode and the heating of the new electrode to the melting point. In addition, the heated by means of electrical resistance Vorwärmöfen are very maintenance-intensive, which manifests itself in high maintenance costs and frequent shutdowns.

Der Erfindung liegt demzufolge die Aufgabe zugrunde, die Wirtschaftlichkeit einer mit Wechselelektroden arbeitenden ESU-Anlage zu verbessern und den Wartungsaufwand zu verringern.The invention is therefore based on the object to improve the efficiency of working with alternating electrodes ESU system and to reduce maintenance.

Diese Aufgabe wird durch eine Vorrichtung mit den Merkmalen des Patentanspruchs 1 sowie durch ein Verfahren mit den Merkmalen des Patentanspruchs 8 gelöst. Vorteilhafte Ausgestaltungen der Erfindung sind in den Unteransprüchen beansprucht.This object is achieved by a device having the features of patent claim 1 and by a method having the features of patent claim 8. Advantageous embodiments of the invention are claimed in the subclaims.

Das erfindungsgemäße Verfahren zeichnet sich dadurch aus, dass die Vorwärmung der Spitze der Abschmelzelektrode im Vorwärmofen durch Verbrennung eines Brennstoffs mit einem Oxidator erfolgt. Dabei wird der Vorwärmofen nach Art eines Zyklonofens betrieben, d.h. Brennstoff und/oder Oxidator werden mit einer - in einer Ebene senkrecht zur Längsachse des Vorwärmofens gesehen - tangentialen Richtungskomponente in den Verbrennungsbereich des Ofens eingetragen. Dies führt zu einer Drallströmung, in der Brennstoff und Oxidatior an der Spitze der vorzuwärmenden Abschmelzelektrode vorbeigeführt werden. Nach Zündung des Brennstoff-Oxidator Gemisches bildet sich somit ein Flammenzyklon aus, der die Spitze der Abschmelzelektrode einhüllt und auf diese Weise gleichmäßig erwärmt. Die Spitze der Abschmelzelektrode kann somit bis zu einer Temperatur aufgeheizt werden, die in der Nähe der Schmelztemperatur des jeweils umzuschmelzenden Materials liegt; dadurch wird insbesondere die Unterbrechungsdauer des Umschmelzvorgangs beim Elektrodenwechsel, also die Zeitdauer zwischen dem Abbruch des Schmelzvorgangs der alten und dem Beginn des Schmelzvorgangs der neuen Elektrode, deutlich verkürzt.The method according to the invention is characterized in that the preheating of the tip of the consumable electrode in the preheating furnace by combustion of a Fuel with an oxidizer takes place. In this case, the preheating furnace is operated in the manner of a cyclone furnace, ie fuel and / or oxidizer are registered with a - viewed in a plane perpendicular to the longitudinal axis of the preheating furnace - tangential direction component in the combustion region of the furnace. This results in a swirling flow in which fuel and oxidant are conducted past the tip of the preheating electrode to be preheated. After ignition of the fuel-oxidizer mixture thus forms a flame cyclone, which envelops the tip of the Abschmelzelektrode and heated evenly in this way. The tip of the Abschmelzelektrode can thus be heated to a temperature which is close to the melting temperature of the material to be remelted in each case; As a result, in particular the interruption duration of the remelting process during the electrode change, that is to say the time duration between the termination of the melting process of the old and the beginning of the melting process of the new electrode, is significantly shortened.

Als Brennstoffe sind gasförmige Brennstoffe, wie beispielsweise Erdgas, ebenso geeignet wie zu einem Aerosol zerstäubte flüssige Brennstoffe oder fluidisierte Feststoffpartikel (Stäube). Insbesondere können Brennstoffe zum Einsatz kommen, die Kohlenstoff, Wasserstoff, Schwefel oder eine Mischung aus zwei oder drei dieser Stoffe oder eine einen oder mehrere dieser Stoffe aufweisende Verbindung enthalten. Als Oxidationsmittel kann Luft oder ein mit Sauerstoff angereichertes Gas (mit einem Sauerstoffanteil von über 21 Vol.-%) zum Einsatz kommen; bevorzugt eignet sich reiner Sauerstoff mit einer Sauerstoffkonzentration von über 90 Vol.-%, besonders bevorzugt mit einer Sauerstoffkonzentration von über 95 Vol.-%.As fuels are gaseous fuels, such as natural gas, as well as aerosol atomized liquid fuels or fluidized solid particles (dusts). In particular, fuels may be used which contain carbon, hydrogen, sulfur or a mixture of two or three of these substances or a compound containing one or more of these substances. The oxidizing agent used can be air or an oxygen-enriched gas (with an oxygen content of more than 21% by volume); Pure oxygen is preferably suitable with an oxygen concentration of more than 90% by volume, particularly preferably with an oxygen concentration of more than 95% by volume.

In axialer Richtung sind die Eintragseinrichtungen entweder senkrecht zur Längsachse des Vorwärmofens oder angeordnet, oder aber winklig, mit ihrer Mündungsöffnung nach oben, also in Richtung auf die vorzuwärmende Abschmelzelektrode weisend, um die Ausbildung einer helikalen Strömung zu begünstigen. Dabei sollte jedoch eine direkte Beaufschlagung der Abschmelzelektrode mit einer Brennerflamme vermieden werden, da dies zu einer lokalen Überhitzung der Abschmelzelektrode führen kann.In the axial direction, the insertion means are either perpendicular to the longitudinal axis of the preheating furnace or arranged, or angular, with its mouth opening facing upwards, ie in the direction of the preheating Abschmelzelektrode to favor the formation of a helical flow. In this case, however, a direct loading of the Abschmelzelektrode should be avoided with a burner flame, as this can lead to a local overheating of Abschmelzelektrode.

Als Eintragseinrichtungen kann beispielsweise eine Anordnung von Lanzen vorgesehen sein, mittels der Brennstoff und Oxidator an jeweils getrennten Orten in den Verbrennungsbereich eingebracht, anschließend vermischt und gezündet werden. Bevorzugt kommen jedoch ein oder mehrere Brenner zum Einsatz, der/die jeweils mindestens eine Zuführung für einen Brennstoff und mindestens eine Zuführung für einen Oxidator aufweist/aufweisen, und bei dem/denen eine Vermischung und Zündung des Brennstoff-Oxidator-Gemisches bereits im Vorfeld der Mündungsöffnung des jeweiligen Brenners erfolgt.By way of example, an arrangement of lances can be provided as insertion devices, by means of which the fuel and oxidizer are introduced at respectively separate locations into the combustion region, subsequently mixed and ignited. However, preference is given to using one or more burners, which in each case have / have at least one feed for a fuel and at least one feed for an oxidizer, and for which mixing and ignition of the fuel-oxidizer mixture already precedes Mouth opening of the respective burner takes place.

Bevorzugt sind zumindest im Endabschnitt des Vorwärmofens mehrere tangential eintragende Lanzen oder Brenner in vorzugsweise gleichmäßigen Winkelabständen angeordnet, um eine gleichmäßige Aufheizung der Elektrodenoberfläche zu gewährleisten.Preferably, at least in the end section of the preheating furnace, a plurality of tangentially carrying lances or burners are arranged at preferably uniform angular intervals in order to ensure uniform heating of the electrode surface.

Eine andere vorteilhafte Ausgestaltung der Erfindung ist dadurch gekennzeichnet, dass die Eintragsvorrichtung bzw. die Eintragsvorrichtungen in ihrer Längen- und/oder Winkelposition verstellbar in der Wandung des Vorwärmofens angeordnet sind. Die Position der Eintragsvorrichtung kann auf diese Weise der Geometrie der jeweils vorzuwärmenden Elektrode angepasst werden. Es ist im Übrigen im Rahmen der Erfindung ebenso vorstellbar, die Position der Eintragsvorrichtung gegenüber der Elektrode während des laufenden Aufwärmvorgangs zu verändern, um eine optimale Wärmebeaufschlagung bei minimalem Energieeinsatz zu erzielen, beispielsweise kann die Elektrode gegenüber dem Vorwärmofen oder dieser gegenüber der Elektrode um deren Längsachse drehbar gelagert sein, um auch bei einer geringen Anzahl von Eintragsvorrichtungen im Vorwärmofen eine gleichmäßige Wärmebeaufschlagung der Elektrodenspitze zu ermöglichen.Another advantageous embodiment of the invention is characterized in that the entry device or the entry devices are arranged in their length and / or angular position adjustable in the wall of the preheating furnace. The position of the entry device can be adapted in this way the geometry of the respective preheating electrode. Incidentally, it is also conceivable within the scope of the invention to change the position of the insertion device relative to the electrode during the current warm-up process in order to achieve optimal heat application with minimum energy input, for example the electrode can be opposite the preheating furnace or opposite the electrode about its longitudinal axis be rotatably mounted to allow even with a small number of entry devices in the preheating a uniform heat application of the electrode tip.

In einer abermals vorteilhaften Weiterbildung der Erfindung ist der Endabschnitt des Vorwärmofens mit einer Abdeckung ausgerüstet, die das Eindringen von Umgebungsatmosphäre unterbinden soll. Bei langen Abschmelzelektroden empfiehlt es sich dabei, die Abdeckung mit einer Aussparung für die Elektrode auszurüsten, sodass im Betrieb die Abschmelzelektrode lediglich mit ihrer Spitze in den von der Abdeckung eingeschlossenen Verbrennungsbereich hineinragt. Bei dieser Ausgestaltung der Erfindung wird also nur der Bereich der Elektrodenspitze intensiv mit heißen Brennergasen beaufschlagt, wobei die Abdeckung zumindest weitgehend verhindert, dass Gase aus der Umgebungsatmosphäre, insbesondere Sauerstoff, in den beheizten Bereich des Vorwärmofens eindringen und an der Oberfläche der Elektrode zu unerwünschten Reaktionen führen. Alternativ kann im Übrigen auch eine die Elektrode vollständig einhüllende Haube eingesetzt werden, beispielsweise eine Haubenkonstruktion der Art, wie sie in der EP 0 727 500 B1 beschrieben ist.In a further advantageous development of the invention, the end portion of the preheating furnace is equipped with a cover which is intended to prevent the ingress of ambient atmosphere. In the case of long melting electrodes, it is advisable in this case to equip the cover with a recess for the electrode, so that in operation the melting electrode protrudes only with its tip into the combustion region enclosed by the cover. At this Embodiment of the invention, therefore, only the area of the electrode tip is intensively charged with hot combustion gases, wherein the cover at least largely prevents gases from the ambient atmosphere, in particular oxygen, penetrate into the heated region of the preheating furnace and lead to undesirable reactions on the surface of the electrode. Alternatively, it is otherwise possible to use a hood which completely envelopes the electrode, for example a hood construction of the type as described in US Pat EP 0 727 500 B1 is described.

Zweckmäßigerweise ist der Vorwärmofen mit einem Abgassystem zur Regelung des Ofendrucks ausgerüstet. Das Abgassystem umfasst beispielsweise Mittel zur Regelung des Drucks oder der Zusammensetzung der Atmosphäre im Ofenraum, wie beispielsweise eine Absaugeinrichtung oder Mittel zur Rezirkulation von Rauchgasen.Conveniently, the preheating furnace is equipped with an exhaust system for controlling the furnace pressure. The exhaust system includes, for example, means for controlling the pressure or the composition of the atmosphere in the furnace chamber, such as a suction device or means for recirculation of flue gases.

Das erfindungsgemäße Verfahren zum Herstellen von Metallblöcken nach dem Elektroschlacke-Umschmelzen von Metallen, bei dem eine Abschmelzelektrode vorgewärmt und anschließend zumindest mit ihrer Spitze in ein metallurgisch wirksames Schlackenbad abgesenkt wird, ist dadurch gekennzeichnet, dass die Vorwärmung der Abschmelzelektrode vor ihrer Zuführung an das Schlackenbad mittels Beaufschlagung von zumindest der Spitze der Abschmelzelektrode mit einem miteinander reagierenden Brennstoff-Oxidator-Gemisch erfolgt.The inventive method for producing metal blocks after the electroslag remelting of metals, in which a Abschmelzelektrode preheated and then lowered at least with its tip in a metallurgical slag bath, is characterized in that the preheating of the Abschmelzelektrode prior to their supply to the slag by means of Applying at least the tip of the Abschmelzelektrode with a mutually reactive fuel-oxidizer mixture takes place.

Eine besonders bevorzugte Ausgestaltung des erfindungsgemäßen Verfahrens sieht dabei vor, die Vorwärmung der Spitze der Abschmelzelektrode durch Ausbildung eines die Spitze einhüllenden Flammenzyklons erfolgt. Ein Flammenzyklon entsteht bei einem tangentialen Eintrag von Brennstoff und/oder Oxidator mittels Lanzen oder Brennern. Die miteinander reagierenden Stoffe werden in einer Drallströmung um die Spitze der Abschmelzelektrode herumgeführt und erwärmen diese gleichmäßig und unter weitgehender Ausschaltung der Gefahr einer lokalen Überhitzung.A particularly preferred embodiment of the method according to the invention provides for the preheating of the tip of the consumable electrode to take place by forming a flame cyclone enveloping the tip. A flame cyclone is created by a tangential entry of fuel and / or oxidizer by means of lances or burners. The substances which react with each other are guided around the tip of the consumable electrode in a swirling flow and heat them up uniformly and with the risk of local overheating being largely eliminated.

Es hat sich herausgestellt, dass die Zeitdauer des Elektrodenwechsels einen wesentlichen Einfluss auf den Kristallisationsvorgang und damit die Qualität des durch ESU erzeugten Metallblocks hat. Je länger die Zeitdauer zwischen der Wegnahme des alten Elektrodenrestes und dem Beginn des Aufschmelzens der Wechselelektrode dauert, desto größer ist die Gefahr der Ausbildung von fehlerhaften Kristallisationen im Grenzbereich zwischen den aufeinanderfolgenden Aufschmelzelektroden zuzuordnenden Materialabschnitten des umgeschmolzenen Metallblocks. Um die Zeitdauer der Unterbrechung des Umschmelzvorgangs während eines Elektrodenwechsels möglichst kurz zu halten, wird daher bei der Vorwärmung zumindest die Spitze der Abschmelzelektrode auf eine Temperatur zwischen 100°C und der Schmelztemperatur des Materials der jeweils vorzuwärmenden Abschmelzelektrode beheizt, bevorzugt zwischen 900°C und 1400°C. Durch die Aufheizung der Abschmelzelektrode auf derart hohe Temperaturen, die nahe an den Schmelzpunkt des jeweils umzuschmelzenden Metalls heranreichen, wird gewährleistet, dass die Abschmelzelektrode bei der anschließenden Zuführung an das Schlackenbad nicht oder nur kurz aufgeheizt werden muss, bis der Umschmelzvorgang wieder einsetzt.It has been found that the duration of the electrode change has a significant influence on the crystallization process and thus the quality of the metal block produced by ESC. The longer the time between the Removal of the old electrode residue and the beginning of the melting of the exchange electrode takes, the greater the risk of the formation of faulty crystallizations in the boundary region between the successive reflow electrodes to be assigned material portions of the remelted metal block. In order to keep the duration of the interruption of the remelting as short as possible during an electrode change, therefore, during preheating at least the tip of the Abschmelzelektrode is heated to a temperature between 100 ° C and the melting temperature of the material of each Abschwezelektrode prehwärmenden, preferably between 900 ° C and 1400 ° C. By heating the Abschmelzelektrode to such high temperatures, which come close to the melting point of the metal to be remelted, it is ensured that the Abschmelzelektrode in the subsequent supply to the slag bath does not have or only briefly heated until the remelting begins again.

Eine vorteilhafte Weiterbildung der Erfindung sieht eine Steuerung vor, mittels der das Verhältnis aus Brennstoff und Oxidationsmittel des Brenners während des Vorwärmvorgangs verändert werden kann. Auf diese Weise kann die Befeuerung im Vorwärmofen optimiert und insbesondere die Temperatur der Brennerflamme genau eingestellt werden. Ebenso ist es auch möglich, mittels der Steuerung den Sauerstoffanteil im eingesetzten Oxidator während des Betriebs des Vorwärmofens zu ändern bzw. zu regeln.An advantageous development of the invention provides a control by means of which the ratio of fuel and oxidant of the burner during the preheating process can be changed. In this way, the firing in the preheating furnace can be optimized and, in particular, the temperature of the burner flame can be precisely set. Likewise, it is also possible to change or regulate the oxygen content in the oxidizer used during the operation of the preheating furnace by means of the controller.

Eine wieder bevorzugte Ausgestaltung der Erfindung ist dadurch gekennzeichnet, dass Maßnahmen getroffen werden, die eine Rezirkulation von Brenngasen in den Bereich vor dem Austritt des Brenners bzw. den Austritten der Brenner ermöglichen und dadurch eine flammenlose - und damit besonders schadstoffarme und energieeffiziente - Verbrennung erfolgt.A further preferred embodiment of the invention is characterized in that measures are taken that allow a recirculation of fuel gases in the area before the exit of the burner or the outlet of the burner and thereby flameless - and thus particularly low-emission and energy-efficient - combustion takes place.

Anhand der Zeichnungen soll nachfolgend ein Ausführungsbeispiel der Erfindung erläutert werden. Die einzige Zeichnung (Fig. 1) zeigt schematisch den Aufbau eines erfindungsgemäßen Vorwärmofens für eine ESU-Anlage im Längsschnitt.With reference to the drawings, an embodiment of the invention will be explained below. The single drawing (Fig. 1) shows schematically the construction of a preheating furnace according to the invention for an ESU plant in longitudinal section.

Der in Fig. 1 gezeigte Vorwärmofen 1 umfasst einen aus feuerfestem Material aufgebauten Ofenmantel 2, dessen nach unten weisender Endabschnitt 3 konisch zugeformt ist. Eine Abdeckplatte 4, die mit einer zentralen Öffnung 5 ausgerüstet ist, schließt den Ofenmantel 2 nach oben ab und umgrenzt somit, gemeinsam mit den Wänden des Ofenmantels 2, einen Verbrennungsbereich 6. Im Bereich des Endabschnitts 3 sind in der Wand des Ofenmantels 2 Durchführungen 7, 8 vorgesehen, in denen in regelmäßigen Winkelabständen mehrere Brenner angeordnet sind, im Ausführungsbeispiel zwei Brenner 9, 10. Bei den Brennern 9, 10 handelt es sich im gezeigten Ausführungsbeispiel um Brenner, mittels denen ein gasförmiger Brennstoff, beispielsweise Erdgas, und Sauerstoff in den Verbrennungsbereich 6 eingetragen und dort verbrannt werden; im Rahmen der Erfindung können jedoch auch andere Brenner zum Einsatz kommen, wie beispielsweise Brenner, die mit einem festen oder flüssigen Brennstoff arbeiten und/oder Brenner, die Luft, mit Sauerstoff angereicherte Luft oder ein Gas mit einem während des Betriebs variablen Sauerstoffanteil als Oxidator einsetzen. Die Brenner 9, 10 ragen dabei tangential in den Vorwärmofen 1 hinein und sind in axialer Hinsicht gegenüber einer zur Längsachse des Vorwärmofens 1 senkrechten Ebene winklig, mit ihren Mündungsöffnungen jeweils nach oben weisend, angeordnet. Im oberen Bereich des Ofenmantels 2, dicht unterhalb der Abdeckplatte 4, ist eine weitere Durchführung 11 angeordnet, in der eine Abgasleitung 12 zum Abführen des Rauchgases eingebaut ist.The preheating furnace 1 shown in Fig. 1 comprises a constructed of refractory material furnace shell 2, the downwardly facing end portion 3 is conically formed. A cover plate 4, which is equipped with a central opening 5, the furnace shell 2 upwards and thus delimits, together with the walls of the furnace shell 2, a combustion region 6. In the region of the end portion 3 are in the wall of the furnace shell 2 bushings 7th 8, in which a plurality of burners are arranged at regular angular intervals, in the exemplary embodiment two burners 9, 10. The burners 9, 10 are burners in the exemplary embodiment shown, by means of which a gaseous fuel, for example natural gas, and oxygen in the Combustion area 6 registered and burned there; However, within the scope of the invention, other burners may also be used, such as burners operating with a solid or liquid fuel and / or burners employing air, oxygen-enriched air or a gas having an oxygen content variable during operation as the oxidizer , The burners 9, 10 protrude tangentially into the preheating furnace 1 and are arranged in an axial direction with respect to a plane perpendicular to the longitudinal axis of the preheating furnace 1 at an angle, each with its mouth openings facing upward. In the upper region of the furnace shell 2, just below the cover plate 4, a further passage 11 is arranged, in which an exhaust pipe 12 is installed for discharging the flue gas.

Beim Betrieb des Vorwärmofens 1 wird eine vorzuwärmende Abschmelzelektrode 13 mit ihrer Spitze 14 durch die Öffnung 5 der Abdeckplatte 4 geführt und so positioniert, dass die Spitze 14 im Bereich des Endabschnitts 3 angeordnet ist, ohne jedoch die Wände des Ofenmantels 2 zu berühren. Alternativ kann die Abdeckplatte 4 auch zweiteilig ausgeführt sein und erst nach der Positionierung der Abschmelzelektrode 13 von beiden Seiten im wesentlichen gasdicht an diese angelegt werden. In jedem Fall ist die zentrale Öffnung 5 der Abdeckplatte 4 dem Außendurchmesser der Abschmelzelektrode 13 angepasst und ermöglicht im Idealfall keinen, im Regelfall nur einen geringen Gasaustausch zwischen dem Verbrennungsbereich 6 und der Umgebungsatmosphäre.During operation of the preheating furnace 1, a preheating electrode 13 is guided with its tip 14 through the opening 5 of the cover plate 4 and positioned so that the tip 14 is arranged in the region of the end portion 3, but without touching the walls of the furnace shell 2. Alternatively, the cover plate 4 may be made in two parts and only after the positioning of the Abschmelzelektrode 13 from both sides substantially gas-tightly applied to this. In any case, the central opening 5 of the cover plate 4 is adapted to the outer diameter of the Abschmelzelektrode 13 and ideally allows no, usually only a small gas exchange between the combustion region 6 and the ambient atmosphere.

Die Positionierung der Abschmelzelektrode 13 wird beispielsweise mittels einer Krananordnung 15 bewirkt, die auch das senkrechte Verfahren der Abschmelzelektrode 13 in den Vorwärmofen 1 hinein und aus diesem hinaus ermöglicht. Über eine Brennstoffzuleitung 16 und eine Sauerstoffzuleitung 17 wird Brennstoff bzw. Sauerstoff zu den Brennern 9, 10 geführt, und das sich jeweils vor den Ausmündungen der Brenner 9, 10 bildende Brennstoff-Oxidationsmittel-Gemisch gezündet. Der Eintrag des Brennstoff-Oxidationsmittel-Gemisches erfolgt jeweils tangential in die Verbrennungszone hinein, wobei die in axialer Hinsicht bestehende Neigung der Brenner 9, 10 in Richtung auf die Spitze 14 der Abschmelzelektrode 13 sowie die konische Zuformung des Endabschnitts 3 insgesamt einen helikalen Verlauf der Strömung im Verbrennungsbereich 6 bewirken. Nach Zündung des Brennstoff-Oxidationsmittel-Gemisches kommt zur Ausbildung eines Flammenzyklons, der die Spitze 14 der Abschmelzelektrode 13 einhüllt und dabei gleichmäßig erhitzt und auf eine Temperatur in der Nähe der Schmelztemperatur des Materials der Abschmelzelektrode 13, beispielsweise auf einen Wert zwischen 900°C und 1400°C, gebracht. Die Temperatur kann dabei mittels einer hier nicht gezeigten Steuerung, die die Zuflüsse von Brennstoff und/oder Oxidationsmittel steuert, eingestellt, bzw. geregelt werden. Um bei unterschiedlichen Ausgestaltungen einer Elektrodenspitze eine optimale Beaufschlagung mit Brenngasen zu ermöglichen, sind die Brenner 9, 10 winkel- und/oder längenverstellbar im Ofenmantel 2 aufgenommen. Die bei der Verbrennung entstehenden Rauchgase werden über die Abgasleitung 12 abgezogen. Eine in der Abgasleitung 12 angeordnete Absaugeinrichtung 18 ermöglicht dabei zugleich die Regelung bzw. Einstellung des Drucks im Verbrennungsbereich 6.The positioning of the Abschmelzelektrode 13 is effected for example by means of a crane assembly 15, which also allows the vertical process of Abschmelzelektrode 13 in the preheating furnace 1 in and out of this. Fuel or oxygen is fed to the burners 9, 10 via a fuel feed line 16 and an oxygen feed line 17, and the fuel-oxidant mixture forming in each case before the outlets of the burners 9, 10 is ignited. The entry of the fuel-oxidizer mixture is in each case tangentially into the combustion zone, wherein the axial tendency of the burner 9, 10 in the direction of the tip 14 of the Abschmelzelektrode 13 and the conical shaping of the end portion 3 a total of a helical course of the flow cause in the combustion region 6. After ignition of the fuel-oxidizer mixture comes to form a flame cyclone, which wraps the tip 14 of the Abschmelzelektrode 13 while heated uniformly and to a temperature near the melting temperature of the material of the Abschmelzelektrode 13, for example to a value between 900 ° C and 1400 ° C, brought. The temperature can be adjusted or regulated by means of a control, not shown here, which controls the inflows of fuel and / or oxidant. In order to enable optimum application of fuel gases to different embodiments of an electrode tip, the burners 9, 10 are angularly and / or length-adjustable accommodated in the furnace shell 2. The resulting during combustion flue gases are withdrawn via the exhaust pipe 12. At the same time, a suction device 18 arranged in the exhaust pipe 12 makes it possible to regulate or adjust the pressure in the combustion region 6.

Besonders vorteilhaft werden die Brenner 9, 10 so ausgelegt, dass es innerhalb des Verbrennungsbereichs 6 zu einer flammenlosen Verbrennung und damit zu einer gleichmäßigen Aufheizung der Spitze 14 der Abschmelzelektrode 13 bei gleichzeitig vermindertem Schadstoffausstoß kommt.Particularly advantageously, the burners 9, 10 are designed so that it comes within the combustion region 6 to a flameless combustion and thus to a uniform heating of the tip 14 of the Abschmelzelektrode 13 at the same time reduced pollutant emissions.

Nachdem die Spitze 14 der Abschmelzelektrode 13 auf einen vorgegebenen Temperaturwert erwärmt wurde, wird die Zufuhr von Brennstoff und Sauerstoff über die Zuleitungen 16, 17 gesperrt. Die Abschmelzelektrode 13 wird aus dem Vorwärmofen 13 abgezogen und der Kokille eines hier nicht gezeigten Elektrodenschlacke-Umschmetzofens zugeführt. Der Vorwärmofen 1 steht danach zur Aufnahme einer weiteren Abschmelzelektrode zur Verfügung.After the tip 14 of the Abschmelzelektrode 13 has been heated to a predetermined temperature value, the supply of fuel and oxygen via the supply lines 16, 17 is blocked. The Abschmelzelektrode 13 is from the Preheating furnace 13 withdrawn and fed to the mold of an electrode slag remelting furnace, not shown here. The preheating furnace 1 is then available for receiving a further Abschmelzelektrode available.

Mit dem erfindungsgemäßen, durch Verbrennung eines Brennstoffs betriebenen Vorwärmofen lässt sich die Vorheizung von Abschmelzelektroden weitaus wirtschaftlicher und bei höheren Temperaturen betreiben, als dies bei konventionellen, elektrisch betriebenen Vorwärmöfen der Fall ist.With the preheating furnace according to the invention, operated by combustion of a fuel, the preheating of melting electrodes can be operated much more economically and at higher temperatures than is the case with conventional, electrically operated preheating furnaces.

Bezugszeichenliste:LIST OF REFERENCE NUMBERS

1.1.
Vorwärmofenpreheating
2.Second
Ofenmantelfurnace shell
3.Third
Endabschnittend
4.4th
Abdeckplattecover
5.5th
Öffnungopening
6.6th
Verbrennungsbereichcombustion zone
7.7th
Durchführungexecution
8.8th.
Durchführungexecution
9.9th
Brennerburner
10.10th
Brennerburner
11.11th
Durchführungexecution
12.12th
Abgasleitungexhaust pipe
13.13th
Abschmelzelektrodeconsumable
14.14th
Spitze (der Abschmelzelektrode)Tip (the consumable electrode)
15.15th
Krananordnungcrane arrangement
16.16th
Brennstoffzuleitungfuel supply line
17.17th
Sauerstoffzuleitungoxygen supply
18.18th
Absaugeinrichtungsuction

Claims (12)

Vorrichtung zum Herstellen von Metallblöcken nach dem Elektroschlacke-Umschmetzverfahren, mit einem metallurgisch wirksamen Schlackenbad und einem Vorwärmofen (1) zum Vorwärmen von zumindest einer Spitze (14) einer dem Schlackenbad zuzuführenden Abschmelzelektrode (13),
dadurch gekennzeichnet, dass der Vorwärmofen (1) in einem im Betriebszustand des Vorwärmofens (1) die Spitze (14) der Abschmelzelektrode (13) aufnehmenden Verbrennungsbereichs (6) mit zumindest einer Eintragseinrichtung (9, 10) für einen Brennstoff und einen Oxidator ausgerüstet ist, die derart angeordnet ist, dass der Brennstoff und/oder das Oxidationsmittel tangential in den Verbrennungsbereich (6) des Vorwärmofens (1) eingetragen werden.
Apparatus for producing metal blocks by the electroslag remelting method, comprising a metallurgically active slag bath and a preheating furnace (1) for preheating at least one tip (14) of a consumable electrode (13) to be supplied to the slag bath,
characterized in that the preheating furnace (1) in a in the operating state of the preheating furnace (1) the tip (14) of the Abschmelzelektrode (13) receiving the combustion region (6) is equipped with at least one entry means (9, 10) for a fuel and an oxidizer , which is arranged such that the fuel and / or the oxidant are introduced tangentially into the combustion region (6) of the preheating furnace (1).
Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Eintragseinrichtungen (9, 10) in axialer Hinsicht winklig, mit ihrer Mündungsöffnung in Richtung auf die Spitze (14) der Abschmelzelektrode (13) geneigt, angeordnet sind.Apparatus according to claim 1, characterized in that the entry means (9, 10) are arranged at an angle in the axial direction, with its mouth opening in the direction of the tip (14) of the Abschmelzelektrode (13) inclined. Vorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, als Eintragseinrichtungen Brenner (9, 10) vorgesehen sind, die jeweils mindestens eine Zuführung für einen Brennstoff und mindestens eine Zuführung für einen Oxidator aufweisen.Apparatus according to claim 1 or 2, characterized in that as entry means burner (9, 10) are provided, each having at least one feed for a fuel and at least one feed for an oxidizer. Vorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, im Endabschnitt (3) des Vorwärmofens (1) mehrerer Brenner (9, 10) in vorzugsweise gleichmäßigen Winkelabständen angeordnet sind.Device according to one of the preceding claims, characterized in that in the end section (3) of the preheating furnace (1) a plurality of burners (9, 10) are arranged at preferably uniform angular intervals. Vorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der bzw. die Brenner (9, 10) in seiner/ihrer Längen- und/oder Winkelposition verstellbar in der Wand des Vorwärmofens (1) angeordnet ist/sind.Device according to one of the preceding claims, characterized in that the burner or burners (9, 10) is / are arranged adjustably in its / their longitudinal and / or angular position in the wall of the preheating furnace (1). Vorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Endabschnitt (3) des Vorwärmofens (1) zum Verhindern des Eindringens von Umgebungsatmosphäre mit einer Abdeckung (4) ausgerüstet ist.Device according to one of the preceding claims, characterized in that the end section (3) of the preheating furnace (1) for preventing the penetration of ambient atmosphere is equipped with a cover (4). Vorrichtung nach einem der vorhergehenden Ansprüche, gekennzeichnet durch ein Abgassystem (12, 18) zur Regelung des Ofendrucks.Device according to one of the preceding claims, characterized by an exhaust system (12, 18) for controlling the furnace pressure. Verfahren zum Herstellen von Metallblöcken nach dem Elektroschlacke-Umschmelzen von Metallen, bei dem eine Abschmelzelektrode (13) vorgewärmt und anschließend mit einer Spitze (14) in ein metallurgisch wirksames Schlackenbad abgesenkt wird,
dadurch gekennzeichnet,
dass die Vorwärmung der Abschmelzelektrode (13) vor ihrer Zuführung an das Schlackenbad durch Beaufschlagen von zumindest der Spitze (14) der Abschmelzelektrode (13) mit einem miteinander reagierenden Brennstoff-Oxidatior-Gemisch erfolgt.
Method for producing metal blocks after the electroslag remelting of metals, in which a consumable electrode (13) is preheated and then lowered with a tip (14) into a metallurgically active slag bath,
characterized,
in that the preheating of the consumable electrode (13) before being fed to the slag bath is effected by pressurizing at least the tip (14) of the consumable electrode (13) with a mutually reactive fuel-oxidant mixture.
Verfahren nach Anspruch 7, dadurch gekennzeichnet, dass die Vorwärmung der Spitze (14) der Abschmelzelektrode (13) durch Ausbildung eines die Spitze (14) einhüllenden Flammenzyklons erfolgt.A method according to claim 7, characterized in that the preheating of the tip (14) of the Abschmelzelektrode (13) by forming a tip (14) enveloping flame cyclone takes place. Verfahren nach Anspruch 7 oder 8, dadurch gekennzeichnet, dass die Spitze (14) der Abschmelzelektrode (13) bei der Vorwärmung auf eine Temperatur zwischen 100°C und der Schmelztemperatur des Materials der Abschmelzelektrode, bevorzugt zwischen 900°C und 1400°C, beheizt wird.A method according to claim 7 or 8, characterized in that the tip (14) of the Abschmelzelektrode (13) in the preheating to a temperature between 100 ° C and the melting temperature of the material of the Abmelzelektrode, preferably between 900 ° C and 1400 ° C, heated becomes. Verfahren nach Anspruch 7 bis 9, dadurch gekennzeichnet, dass das Verhältnis aus Brennstoff und Oxidationsmittel und/oder den Sauerstoffgehalt im Oxidator während der Vorwärmung verändert oder geregelt wird.A method according to claim 7 to 9, characterized in that the ratio of fuel and oxidant and / or the oxygen content in the oxidizer is changed or regulated during preheating. Verfahren nach Anspruch 7 bis 10, dadurch gekennzeichnet, dass die Verbrennung des Brennstoffs flammenlos erfolgt.A method according to claim 7 to 10, characterized in that the combustion of the fuel is flameless.
EP14186604.6A 2013-09-28 2014-09-26 Device and method for electro-slag remelting Active EP2853610B1 (en)

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SI201430578T SI2853610T1 (en) 2013-09-28 2014-09-26 Device and method for electro-slag remelting
RS20180087A RS56789B1 (en) 2013-09-28 2014-09-26 Device and method for electro-slag remelting
PL14186604T PL2853610T3 (en) 2013-09-28 2014-09-26 Device and method for electro-slag remelting
HRP20180138TT HRP20180138T1 (en) 2013-09-28 2018-01-24 Device and methdo for electro-slag remelting

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CN104831082A (en) * 2015-05-26 2015-08-12 重庆钢铁(集团)有限责任公司 Electroslag smelting electric furnace system

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CN104831083B (en) * 2015-05-26 2017-07-28 重庆钢铁(集团)有限责任公司 electroslag smelting furnace device

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DE2755478A1 (en) 1977-12-13 1979-06-21 Inst Elektroswarki Patona Electroslag remelting plant - using two electrode holders, each mounted on a swivel arm for rapid electrode replacement
EP0727500B1 (en) 1995-02-20 2000-04-19 Inteco Internationale Technische Beratung Gesellschaft mbH Method and installation for producing metal ingots
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DE2124960A1 (en) 1971-05-19 1973-02-01 Boehler & Co Ag Geb PROCESS FOR THE PRODUCTION OF BLOCKS MADE OF STEEL AND METAL ALLOYS BY MEANS OF ELECTRO-SLAG RE-MELTING WITH ELECTRODE CHANGE
DE2755478A1 (en) 1977-12-13 1979-06-21 Inst Elektroswarki Patona Electroslag remelting plant - using two electrode holders, each mounted on a swivel arm for rapid electrode replacement
EP0727500B1 (en) 1995-02-20 2000-04-19 Inteco Internationale Technische Beratung Gesellschaft mbH Method and installation for producing metal ingots
DE10128168C1 (en) 2001-06-09 2002-10-24 Ald Vacuum Techn Ag Production of metal ingots in a mold comprises re-melting several melting electrodes by exchanging the electrodes according to an electroslag re-melting process in a controlled atmosphere

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104831082A (en) * 2015-05-26 2015-08-12 重庆钢铁(集团)有限责任公司 Electroslag smelting electric furnace system

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PL2853610T3 (en) 2018-04-30
HUE035556T2 (en) 2018-05-02
ES2654892T3 (en) 2018-02-15
HRP20180138T1 (en) 2018-03-09
RS56789B1 (en) 2018-04-30
DE102013016192B3 (en) 2015-01-15
EP2853610B1 (en) 2017-11-15
EP2853610A3 (en) 2015-04-08

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