EP0476534A1 - Apparatus for the purification of molten non-ferrous metals, in particular molten aluminium - Google Patents

Apparatus for the purification of molten non-ferrous metals, in particular molten aluminium Download PDF

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Publication number
EP0476534A1
EP0476534A1 EP91115522A EP91115522A EP0476534A1 EP 0476534 A1 EP0476534 A1 EP 0476534A1 EP 91115522 A EP91115522 A EP 91115522A EP 91115522 A EP91115522 A EP 91115522A EP 0476534 A1 EP0476534 A1 EP 0476534A1
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EP
European Patent Office
Prior art keywords
melt
chamber
cleaned
tub
central chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
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EP91115522A
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German (de)
French (fr)
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EP0476534B1 (en
Inventor
Hans Peter Dr. Krug
Werner Dr. Schultze
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vereinigte Aluminium Werke AG
Vaw Aluminium AG
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Vereinigte Aluminium Werke AG
Vaw Aluminium AG
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Publication of EP0476534A1 publication Critical patent/EP0476534A1/en
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B21/00—Obtaining aluminium
    • C22B21/06—Obtaining aluminium refining
    • C22B21/066—Treatment of circulating aluminium, e.g. by filtration
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B21/00—Obtaining aluminium
    • C22B21/06—Obtaining aluminium refining
    • C22B21/064—Obtaining aluminium refining using inert or reactive gases
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/05—Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ
    • C22B9/055—Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ while the metal is circulating, e.g. combined with filtration

Definitions

  • the invention relates to a device for cleaning non-ferrous metal melts, in particular aluminum melts, by flotation of the contaminants and degassing by reducing the hydrogen partial pressure in the melt, optionally in connection with chlorination, consisting of a heating system provided and closed by a removable cover Trough or the like., A feed for the melt to be cleaned and a discharge for the cleaned melt and from a flushing gas supply line which introduces the purge gas into the melt in the lower region of the trough.
  • Aluminum melts in particular those made from recycling material, are known to contain considerable amounts of metallic and also non-metallic impurities which have to be removed from the melt before casting. It is known that aluminum melts, as well as melts of aluminum alloys, can be cleaned with the aid of a flushing gas, such as in particular nitrogen and / or argon, optionally with the addition of chlorine, by introducing the flushing gas into the melt in such a way that it is fine-bubbled distributed and flows upwards in the melt, which is simultaneously whirled through.
  • a flushing gas such as in particular nitrogen and / or argon
  • the cleaning effect is based on flotation, since the impurities can be flushed to the surface of the melt by the rising inert flushing gas and removed here as scabies, but on the other hand on the reduction in the hydrogen partial pressure in the melt, as a result of which the hydrogen in the flushing gas is desorbed and can be dissipated via this.
  • metallic impurities such as, in particular, sodium, lithium, magnesium and calcium, can also be chemically reacted and slagged so that they can be removed with the dross floating on the molten pool.
  • a cleaning process of the aforementioned type has been introduced in the aluminum industry under the name "inert gas flotation".
  • the purging gas is supplied via at least one tube immersed in the melt from above or a gas purging plug attached to the bottom of the vessel; the tube can have a driven rotor as a stirring element at its lower end, with the aid of which the melt is circulated in the trough, the turbulence generated a fine distribution of the incoming purge gas, e.g. caused in the melt.
  • Cleaning devices operating according to the aforementioned method either have a heating jacket arranged on the circumference of the tub in jacket insulation or an internal heating system with the aid of heating rods immersed in the tub or channel inductors arranged on the tub for inductive heating.
  • a cleaning method for aluminum melts is known from EU-OS 0 065 854, which however works in batches.
  • the melt to be cleaned is also in a closed box with the help of an agitator whirled around, aluminum fluoride being introduced into the melt from above in order to bind the alkali and alkaline earth metals contained in the melt as impurities and to remove them from the melt.
  • the invention is based on the device mentioned at the outset, which operates according to the method known in practice as an inert gas flotation process. It is based primarily on the task of designing this cleaning device for non-ferrous metal melts, in particular for aluminum melts and melts made of aluminum alloys, in such a way that the cleaning process, if appropriate also with smaller amounts of flushing gas, such as, in particular, argon and / or nitrogen, is optionally carried out Add chlorine, more effective and less prone to failure.
  • flushing gas such as, in particular, argon and / or nitrogen
  • a central chamber formed by an inner tube is arranged in the tub, which is connected in its end region to the tub space on the circumference of the inner tube, and that the purge gas supply and the supply for the melt to be cleaned is assigned to the central chamber , while the discharge for the cleaned melt is assigned to the trough space surrounding the central chamber.
  • the inner tube is surrounded by further tubular elements, which form a system of enclosing chambers in the tub, which are connected to one another in the head or foot region of the tubular elements in a siphon-labyrinth manner, with the derivation for the cleaned melt of the ring-shaped External chamber of the chamber system is assigned.
  • a central chamber formed by an inner tube is arranged in the trough closed by the cover, which also supplies the purge gas the feed for the melt to be cleaned is assigned, the latter advantageously being located at the head of the central chamber, while the purge gas is introduced into the lower region of the central chamber.
  • the central chamber formed by the inner tube has a considerably smaller volume than the trough. This results in the possibility of applying the purging gas to the melt to be cleaned in a small space in countercurrent, whereby particularly intensive mixing and swirling of the purging gas in the melt can be achieved. This also makes it possible to dispense with a powerful agitator that mixes the entire volume of the melt in the tub and sets it in turbulence, and experience has shown that it is particularly susceptible to faults.
  • the arrangement of an agitator in the central chamber can optionally be dispensed with, although it is generally advisable to provide a smaller agitator in the central chamber in order to increase the mixing and swirling effect.
  • the purge gas supply expediently consists of an immersion tube or the like which dips into the central chamber from above and is preferably connected to the cover of the tub. with purge gas outlet at its lower end.
  • a driven stirring element can also be arranged at the lower end of the immersion tube, expediently in conjunction with a rotary nozzle which serves to supply the flushing gas.
  • the agitator can be made simpler, since it essentially only stirs or swirls the volume of the melt located in the central chamber.
  • said inner tube is surrounded by further tube elements which form a system of enclosing chambers in the tub, which are connected to one another in the head or foot region for the flow of the melt in a siphon-labyrinthine manner, then flows through Melt from the central chamber from the individual chambers formed between the tubular elements with increasing decreasing speed, so that the purge gas and also the Dross components have ample opportunity to escape or collect on the surface of the weld pool.
  • This makes it possible to collect and remove the contaminants separated by flotation in the calmed intermediate chambers which surround the central chamber.
  • This can be done in an advantageous manner via a closable dross removal opening arranged on the cover of the tub above the intermediate chambers.
  • the cleaned melt can then be withdrawn from the head space of the outer chamber, expediently via a discharge pipe or the like which leads into the outer chamber in the head region and passes through the jacket of the trough.
  • the arrangement is expediently such that the central chamber formed by the inner tube is connected only in its foot region to the chamber for the melt flow that surrounds it.
  • the annular outer chamber is preferably connected only in its foot region to the intermediate chamber adjacent to it for the melt flow.
  • the inner tube as well as the other tube elements are advantageously cylindrical and arranged so that they surround each other concentrically.
  • the inner tube and also the tube elements are preferably made of ceramic material, in particular one which is resistant to temperature shock and change and is also resistant to chlorine gas.
  • the tube elements formed by the inner tube and the tubes surrounding it connected to a tube package that can be lifted out of the tub as a structural unit and inserted into the tub.
  • the tubular elements can also be connected to the removable cover of the tub to form a structural unit.
  • the siphon-labyrinthine connection of the chambers can also be formed by jacket openings in the tubular elements.
  • the entire cleaning device For the rest, it is advisable to design the entire cleaning device so that it can be tilted about a transverse axis. When the cover is removed, the alloy can be quickly changed by tilting the cleaning device. In order to be able to make do with as few cleaning devices as possible in a foundry, the entire cleaning device is expediently designed to be mobile.
  • the cleaning device shown consists of a crucible or a tub 1, which is made, for example, of chromium-alloyed cast iron and can be closed by means of a removable cover 2, so that a cleaning box which is closed for the cleaning operation is formed.
  • a heating system with electrical heating elements 3 is provided on the outer jacket and in the bottom area of the tub 1 and also for the removable lid, which are located in an insulation 4 surrounding the tub in the jacket and bottom area, which is enclosed by a furnace jacket 30.
  • the insulation 4 suitably consists of a refractory material or the like.
  • the tub 1 there are internals which are formed by tubular elements and form a system of enclosing chambers which are connected to one another in the head or foot region of the tubular elements in a siphon-labyrinth-like manner for the flow of the melt.
  • the internals are formed by an inner tube 5 arranged in the vertical axis of the tub 1 and a plurality of tube elements 6 to 9 concentrically enclosing the inner tube 5 with approximately the same radial spacings in the exemplary embodiment shown.
  • the inner tube 5 forms in the tub 1 a central chamber 10 which is surrounded by a plurality of annular chambers, namely the intermediate chambers 11 to 14 and the outer chamber 15.
  • the central chamber 10 is connected only in its foot area at 16 to the intermediate chamber 11 surrounding it for melt flow, while the intermediate chamber 11 only in the head area at 17 with the adjacent intermediate chamber 12, the latter only in the foot area at 18 with the following intermediate chamber 13 and this only in the head area at 19 is connected to the intermediate chamber 14 for the melt flow, the outer chamber 15 being connected to the adjacent intermediate chamber 14 only in the foot area at 20.
  • the coherent siphon-labyrinth-like channel system is formed by the tube elements 5 to 9.
  • the flow openings 16 to 20 are expediently formed by jacket openings in the end regions of the various tubular elements 5 to 9. But they can also be formed in that the tubular elements are axially offset from one another in such a way that they end at a distance from the bottom of the tub or the cover.
  • the tubular elements 5 to 9 are expediently cylindrical and arranged so that they surround each other concentrically. Instead, the tubular elements could also have an outline shape deviating from the cylindrical shape.
  • the tubular elements preferably consist of a ceramic material, in particular one which is resistant to temperature shock and also to chlorine gas.
  • the tubular elements 5 to 9 are expediently connected to one another to form a tube package which can be lifted up out of the tub 1 as a structural unit or inserted into the tub as a structural unit from above.
  • the tubular elements can also be connected to the cover 2 so that they can be lifted out of the tub 1 after the cover has been released.
  • the feed 21 for the melt to be cleaned is assigned to the central chamber 10 and is located at the head of the central chamber. It consists of a filler neck or the like arranged on the cover 2.
  • the purge gas supply is also assigned to the central chamber 10. It is designed so that the purge gas supplied from the outside exits in the lower region into the central chamber 10 and therefore rises in the countercurrent to the melt in the central chamber 10.
  • the purge gas supply is formed by an immersion tube 22, which dips into the central chamber 10 from above and is connected to the cover 2 and which has the purge gas outlet at its lower end.
  • the immersion tube 22 can form the stator of a rotor 23 arranged at its lower end, which represents a stirring element which stirs and swirls the melt located in the central chamber 10 and is driven by a motor 28 arranged above the cover 2.
  • the supplied purge gas can escape into the melt via rotating nozzles which rotate with the rotor 23.
  • the discharge line for the cleaned melt is assigned to the annular outer chamber 15. It consists of a discharge pipe 24 which opens into the outer chamber 15 in the head region and which crosses through the casing of the tub 1 and its insulation 4 is passed through.
  • the cover 2 has in its peripheral region above the chambers 11 to 15 a dross removal opening 25 or the like by means of a removable closure plate 26. is closed.
  • the purification of the melt with the aid of the purge gas takes place in a manner known per se, on the one hand, by flotation of the impurities and, on the other hand, in that the hydrogen partial pressure in the melt is reduced by the purge gas, so that the hydrogen is desorbed from the purge gas bubbles rising in the melt Melt is removed.
  • the non-metallic impurities rise with the gas bubbles in the melt and are deposited in the area of the chambers 11 to 14 as a dross layer 27 on the surface of the melt pool, so that they can be removed when the dross removal opening 25 is open.
  • An inert gas generally nitrogen and / or argon, is used as the flushing gas, to which chlorine gas can be added in order to convert potassium or alkaline earth metals, such as in particular sodium, lithium, magnesium and calcium, contained in the contaminated melt to chlorides, which are converted by the Flotation effect go into the scabies 27 and can be removed with this. It is possible to add a covering salt as a melting agent to the floating scabies 27, which binds the floating impurities to form a closed scabbing layer.
  • the cleaning device described can work in continuous operation, that is to say with continuous passage of the melt through the cleaning device. Since the melt introduced from above into the central chamber 10 flows in countercurrent from the flushing gas introduced into the lower region into the central chamber 10, there is an intensive exposure of the melt to the flushing gas, which ascending through the melt. The melt is additionally stirred or brought into turbulence by the driven stirring element 23, whereby the purging gas contact with the melt is further improved. The melt flows through the siphon-labyrinth-like chamber system 11 to 15 with a continuously decreasing flow rate, so that here the flushing gas and the dross components have sufficient opportunity to escape from the melt or to settle on the surface of the melt pool.
  • the cleaned melt leaves the closed cleaning chamber in the head region of the outer chamber 15.
  • a collecting collar or the like can be placed on the outer tubular element. be provided to ensure a uniform overflow of the melt over the circumference of the last tube.
  • the cleaned melt then runs out of the collecting collar, for example via a collecting trough, to the downstream casting machine.
  • Exhaust gases such as chlorine in particular, can be drawn off in a small space due to the compact design of the cleaning device and implemented in an environmentally friendly manner in an Al2O3 bed to AlCl3.
  • the entire cleaning device is expediently designed to be mobile in order to be able to use as few cleaning devices as possible within a foundry. It is also advisable to design the cleaning device in such a way that it can be tilted about a transverse axis in order to be able to change the alloy quickly if necessary.
  • tubular elements arranged in the tub 1 can be different. If necessary, only one central tube element 5 can also be provided, although it is preferable to arrange several tubular elements that are enclosed.

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  • Manufacturing & Machinery (AREA)
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Abstract

The invention relates to an apparatus for the purification of molten non-ferrous metals, in particular molten aluminium and the like, by flotation of the impurities and degassing by reducing the hydrogen partial pressure in the melt with the aid of a flushing gas flowing through the melt inside a closed chamber formed by a trough (1) or the like provided with a removable cover (2). According to the invention, the trough (1) is provided with a central chamber (10) which is formed by an inner tube (5) and which is connected in its end region to the trough chamber at the circumference of the inner tube, the flushing gas feed and the feed for the melt to be purified being associated with the central chamber. Preferably, the inner tube (5) is concentrically enclosed by further tubular elements (6 to 9) which form a chamber system in the trough connected in syphon-and-labyrinth fashion for the melt to flow through. The purification apparatus according to the invention makes it possible to achieve a particularly effective purification of the melt even with reduced amounts of flushing gas. <IMAGE>

Description

Die Erfindung betrifft eine Vorrichtung zum Reinigen von NE-Metallschmelzen, insbesondere von Aluminiumschmelzen, durch Flotation der Verunreinigungen und Entgasung durch Herabsetzung des Wasserstoffpartialdrucks in der Schmelze, gegebenenfalls in Verbindung mit einer Chlorierung, bestehend aus einer mit einem Heizsystem versehenen, durch eine entfernbare Abdeckung geschlossenen Wanne od.dgl., einer Zuführung für die zu reinigende Schmelze und einer Ableitung für die gereinigte Schmelze und aus einer das Spülgas im unteren Bereich der Wanne in die Schmelze einführenden Spülgaszuleitung.The invention relates to a device for cleaning non-ferrous metal melts, in particular aluminum melts, by flotation of the contaminants and degassing by reducing the hydrogen partial pressure in the melt, optionally in connection with chlorination, consisting of a heating system provided and closed by a removable cover Trough or the like., A feed for the melt to be cleaned and a discharge for the cleaned melt and from a flushing gas supply line which introduces the purge gas into the melt in the lower region of the trough.

Aluminiumschmelzen, insbesondere solche aus Recyclingmaterial, enthalten bekanntlich in erheblichem Maße metallische und auch nichtmetallische Verunreinigungen, die vor dem Vergießen aus der Schmelze entfernt werden müssen. Es ist bekannt, daß sich Aluminiumschmelzen, wie auch Schmelzen von Aluminiumlegierungen, mit Hilfe eines Spülgases, wie insbesondere Stickstoff und/oder Argon, gegebenenfalls mit Chlorzusatz, reinigen lassen, indem das Spülgas so in die Schmelze eingeführt wird, daß es sich in dieser feinperlig verteilt und in der Schmelze aufwärtsströmt, wobei diese zugleich durchwirbelt wird.Aluminum melts, in particular those made from recycling material, are known to contain considerable amounts of metallic and also non-metallic impurities which have to be removed from the melt before casting. It is known that aluminum melts, as well as melts of aluminum alloys, can be cleaned with the aid of a flushing gas, such as in particular nitrogen and / or argon, optionally with the addition of chlorine, by introducing the flushing gas into the melt in such a way that it is fine-bubbled distributed and flows upwards in the melt, which is simultaneously whirled through.

Die Reinigungswirkung beruht hinsichtlich der partikelförmigen Verunreinigungen auf Flotation, da die Verunreinigungen durch das aufsteigende inerte Spülgas an die Oberfläche der Schmelze gespült und hier als Krätze abgezogen werden können, andererseits aber auf die Herabsetzung des Wasserstoffpartialdrucks in der Schmelze, wodurch der Wasserstoff im Spülgas desorbiert und über dieses abgeführt werden kann. Durch Beimischung von Chlor zu dem Spülgas lassen sich auch metallische Verunreinigunge, wie vor allem Natrium, Lithium, Magnesium und Calcium, chemisch unter Chlorbildung umsetzen und verschlacken, so daß sie mit der auf dem Schmelzbad aufschwimmenden Krätze abgezogen werden können.With regard to the particulate impurities, the cleaning effect is based on flotation, since the impurities can be flushed to the surface of the melt by the rising inert flushing gas and removed here as scabies, but on the other hand on the reduction in the hydrogen partial pressure in the melt, as a result of which the hydrogen in the flushing gas is desorbed and can be dissipated via this. By adding chlorine to the purge gas, metallic impurities, such as, in particular, sodium, lithium, magnesium and calcium, can also be chemically reacted and slagged so that they can be removed with the dross floating on the molten pool.

Ein Reinigungsprozeß der vorgenannten Art hat sich in der Aluminiumindustrie unter der Bezeichnung "Inertgas-Flotation" eingeführt. Bei diesem Reinigungsprozeß wird das Spülgas über mindestens ein von oben in die Schmelze eintauchendes Rohr oder einen am Boden des Gefäßes angebrachten Gasspülstein zugeführt; das Rohr kann an seinem unteren Ende einen angetriebenen Rotor als Rührelement aufweisen, mit dessen Hilfe die Schmelze in der Wanne umgewälzt wird, wobei die erzeugte Turbulenz eine feine Verteilung des eintretenden Spülgases z.B. in die Schmelze bewirkt. Nach dem vorgenannten Verfahren arbeitende Reinigungsvorrichtungen weisen entweder einen am Umfang der Wanne in einer Mantelisolierung angeordneten Heizmantel oder eine Innenbeheizung mit Hilfe von in die Wanne eintauchenden Heizstäben oder an der Wanne angeordneten Rinneninduktoren zur induktiven Erwärmung auf. Diese Reinigungsöfen nach Intergas-Flotation-Verfahren ermöglichen eine "in-line-Reinigung", d.h. eine Reinigung mit kontinuierlichem Durchfluß der Schmelze durch die Wanne bzw. den Reinigungsofen.A cleaning process of the aforementioned type has been introduced in the aluminum industry under the name "inert gas flotation". In this cleaning process, the purging gas is supplied via at least one tube immersed in the melt from above or a gas purging plug attached to the bottom of the vessel; the tube can have a driven rotor as a stirring element at its lower end, with the aid of which the melt is circulated in the trough, the turbulence generated a fine distribution of the incoming purge gas, e.g. caused in the melt. Cleaning devices operating according to the aforementioned method either have a heating jacket arranged on the circumference of the tub in jacket insulation or an internal heating system with the aid of heating rods immersed in the tub or channel inductors arranged on the tub for inductive heating. These cleaning ovens according to the intergas flotation process enable "in-line cleaning", i.e. cleaning with continuous flow of the melt through the tub or the cleaning oven.

Aus der EU-OS 0 065 854 ist ein Reinigungsverfahren für Aluminiumschmelzen bekannt, das allerdings chargenweise arbeitet. Bei diesem Verfahren wird die zu reinigende Schmelze ebenfalls in einer geschlossenen Box mit Hilfe eines Rührwerks umgewirbelt, wobei zugleich von oben Aluminiumfluorid in die Schmelze eingeführt wird, um die in der Schmelze als Verunreinigungen enthaltenen Alkali- und Erdalkalimetalle zu binden und aus der Schmelze zu entfernen.A cleaning method for aluminum melts is known from EU-OS 0 065 854, which however works in batches. In this process, the melt to be cleaned is also in a closed box with the help of an agitator whirled around, aluminum fluoride being introduced into the melt from above in order to bind the alkali and alkaline earth metals contained in the melt as impurities and to remove them from the melt.

Die Erfindung geht von der eingangs genannten Vorrichtung aus, die nach dem in der Praxis als Inertgas-Flotations-Prozeß bekannten Verfahren arbeitet. Ihr liegt vor allem die Aufgabe zugrunde, diese Reinigungsvorrichtung für NE-Metallschmelzen, insbesondere für Aluminiumschmelzen und Schmelzen aus Aluminiumlegierungen, so auszubilden, daß sich der Reinigungsprozeß, gegebenenfalls auch mit geringeren Mengen an Spülgas, wie vor allem Argon und/oder Stickstoff, gegebenenfalls mit Chlorzusatz, wirkungsvoller und weniger störungsanfällig durchführen läßt.The invention is based on the device mentioned at the outset, which operates according to the method known in practice as an inert gas flotation process. It is based primarily on the task of designing this cleaning device for non-ferrous metal melts, in particular for aluminum melts and melts made of aluminum alloys, in such a way that the cleaning process, if appropriate also with smaller amounts of flushing gas, such as, in particular, argon and / or nitrogen, is optionally carried out Add chlorine, more effective and less prone to failure.

Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß in der Wanne eine von einem Innenrohr gebildete Zentralkammer angeordnet ist, die in ihrem Endbereich mit dem Wannenraum am Umfang des Innenrohres verbunden ist, und daß die Spülgaszuführung sowie die Zuführung für die zu reinigende Schmelze der Zentralkammer zugeordnet ist, während die Ableitung für die gereinigte Schmelze dem die Zentralkammer umschließenden Wannenraum zugeordnet ist. In ihrer bevorzugten Ausführung ist dabei das Innenrohr von weiteren Rohrelementen umschlossen, die in der Wanne ein System von sich umschließenden Kammern bilden, welche im Kopf- bzw. Fußbereich der Rohrelemente siphon-labyrinthartig miteinander verbunden sind, wobei die Ableitung für die gereinigte Schmelze der ringförmigen Außenkammer des Kammersystems zugeordnet ist.This object is achieved in that a central chamber formed by an inner tube is arranged in the tub, which is connected in its end region to the tub space on the circumference of the inner tube, and that the purge gas supply and the supply for the melt to be cleaned is assigned to the central chamber , while the discharge for the cleaned melt is assigned to the trough space surrounding the central chamber. In its preferred embodiment, the inner tube is surrounded by further tubular elements, which form a system of enclosing chambers in the tub, which are connected to one another in the head or foot region of the tubular elements in a siphon-labyrinth manner, with the derivation for the cleaned melt of the ring-shaped External chamber of the chamber system is assigned.

Nach der Erfindung ist also in der von der Abdeckung geschlossenen Wanne eine von einem Innenrohr gebildete Zentralkammer angeordnet, der die Spülgaszuführung und auch die Zuführung für die zu reinigende Schmelze zugeordnet ist, wobei letztere zweckmäßig sich am Kopf der Zentralkammer befindet, während das Spülgas in den unteren Bereich der Zentralkammer eingeleitet wird. Die von dem Innenrohr gebildete Zentralkammer weist ein erheblich kleineres Volumen auf als die Wanne. Damit ergibt sich die Möglichkeit, die zu reinigende Schmelze auf kleinem Raum im Gegenstrom mit dem Spülgas zu beaufschlagen, wodurch sich eine besonders intensive Durchmischung und Verwirbelung des Spülgases in der Schmelze erreichen läßt. Damit ist es auch möglich, auf ein leistungsstarkes Rührwerk, welches das gesamte Volumen der in der Wanne befindlichen Schmelze durchmischt und in Turbulenz versetzt und erfahrungsgemäß besonders störanfällig ist, zu verzichten. Von der Anordnung eines Rührwerks in der Zentralkammer kann gegebenenfalls abgesehen werden, obwohl es sich im allgemeinen empfiehlt, in der Zentralkammer ein kleineres Rührwerk vorzusehen, um den Durchmischungs- und Verwirbelungseffekt zu erhöhen. Die Spülgaszuführung besteht zweckmäßig aus einem von oben in die Zentralkammer eintauchenden, vorzugsweise mit der Abdeckung der Wanne verbundenen Tauchrohr od.dgl. mit Spülgasaustritt an seinem unteren Ende. Dabei kann am unteren Ende des Tauchrohres auch ein angetriebenes Rührorgan angeordnet sein, zweckmäßig in Verbindung mit einer der Spülgaszuführung dienenden Drehdüse. Das Rührwerk kann in jedem Fall einfacher ausgeführt werden, da es im wesentlichen nur das in der Zentralkammer befindliche Volumen der Schmelze umrührt bzw. verwirbelt.According to the invention, a central chamber formed by an inner tube is arranged in the trough closed by the cover, which also supplies the purge gas the feed for the melt to be cleaned is assigned, the latter advantageously being located at the head of the central chamber, while the purge gas is introduced into the lower region of the central chamber. The central chamber formed by the inner tube has a considerably smaller volume than the trough. This results in the possibility of applying the purging gas to the melt to be cleaned in a small space in countercurrent, whereby particularly intensive mixing and swirling of the purging gas in the melt can be achieved. This also makes it possible to dispense with a powerful agitator that mixes the entire volume of the melt in the tub and sets it in turbulence, and experience has shown that it is particularly susceptible to faults. The arrangement of an agitator in the central chamber can optionally be dispensed with, although it is generally advisable to provide a smaller agitator in the central chamber in order to increase the mixing and swirling effect. The purge gas supply expediently consists of an immersion tube or the like which dips into the central chamber from above and is preferably connected to the cover of the tub. with purge gas outlet at its lower end. In this case, a driven stirring element can also be arranged at the lower end of the immersion tube, expediently in conjunction with a rotary nozzle which serves to supply the flushing gas. In any case, the agitator can be made simpler, since it essentially only stirs or swirls the volume of the melt located in the central chamber.

Wird, wie in bevorzugter Ausführung vorgesehen, das genannte Innenrohr von weiteren Rohrelementen umschlossen, die in der Wanne ein System von sich umschließenden Kammern bilden, welche im Kopf- bzw. Fußbereich für den Durchfluß der Schmelze siphon-labyrinthartig miteinander verbunden sind, so durchströmt die Schmelze von der Zentralkammer aus die einzelnen zwischen den Rohrelementen gebildeten Kammern mit zunehmend abnehmender Geschwindigkeit, so daß das Spülgas und auch die Krätzebestandteile ausreichend Gelegenheit bekommen zu entweichen bzw. sich an der Oberfläche des Schmelzbades zu sammeln. Damit ist es möglich, die durch Flotation ausgeschiedenen Verunreinigungen in den beruhigten Zwischenkammern, die die Zentralkammer umschließen, aufzufangen und aus diesen abzuziehen. Dies kann in vorteilhafter Weise über eine an der Abdeckung der Wanne oberhalb der Zwischenkammern angeordnete verschließbare Krätze-Entnahmeöffnung geschehen. Die gereinigte Schmelze kann dann aus dem Kopfraum der Außenkammer abgezogen werden, zweckmäßig über ein im Kopfbereich in die Außenkammer mündendes, durch den Mantel der Wanne hindurchführendes Ableitungsrohr od.dgl.If, as is provided in a preferred embodiment, said inner tube is surrounded by further tube elements which form a system of enclosing chambers in the tub, which are connected to one another in the head or foot region for the flow of the melt in a siphon-labyrinthine manner, then flows through Melt from the central chamber from the individual chambers formed between the tubular elements with increasing decreasing speed, so that the purge gas and also the Dross components have ample opportunity to escape or collect on the surface of the weld pool. This makes it possible to collect and remove the contaminants separated by flotation in the calmed intermediate chambers which surround the central chamber. This can be done in an advantageous manner via a closable dross removal opening arranged on the cover of the tub above the intermediate chambers. The cleaned melt can then be withdrawn from the head space of the outer chamber, expediently via a discharge pipe or the like which leads into the outer chamber in the head region and passes through the jacket of the trough.

Mit Hilfe der erfindungsgemäßen Reinigungsvorrichtung ergibt sich die Möglichkeit bei gleicher Spülwirkung mit kleineren Spülgasmengen ohne Totraumzonen, wie sie in eckigen Gefäßen bestehen, effektiver zu arbeiten. Der gesamte Reinigungsprozeß wie auch die Zu- und Ableitung der Schmelze und auch das Entfernen der als Krätze aufschwimmenden Verunreinigungen lassen sich leicht beherrschen.With the help of the cleaning device according to the invention, it is possible to work more effectively with the same purging effect with smaller amounts of purge gas without dead space zones, such as exist in angular vessels. The entire cleaning process as well as the supply and discharge of the melt and also the removal of the contaminants floating as dross can be easily mastered.

Im einzelnen wird die Anordnung zweckmäßig so getroffen, daß die von dem Innenrohr gebildete Zentralkammer nur in ihrem Fußbereich mit der sie umschließenden Kammer für den Schmelzedurchfluß verbunden ist. Bei mehreren sich konzentrisch umschließenden Rohrelementen wird vorzugsweise die ringförmige Außenkammer nur in ihrem Fußbereich mit der ihr benachbarten Zwischenkammer für den Schmelzedurchfluß verbunden. Das Innenrohr wie auch die weiteren Rohrelemente werden vorteilhafterweise zylindrisch ausgebildet und so angeordnet, daß sie sich konzentrisch umschließen. Vorzugsweise bestehen das Innenrohr und auch die Rohrelemente aus Keramikmaterial, insbesondere einem solchen, das temperaturschock- und wechselbeständig und auch gegen Chlorgas beständig ist.In detail, the arrangement is expediently such that the central chamber formed by the inner tube is connected only in its foot region to the chamber for the melt flow that surrounds it. In the case of a plurality of concentrically enclosing tubular elements, the annular outer chamber is preferably connected only in its foot region to the intermediate chamber adjacent to it for the melt flow. The inner tube as well as the other tube elements are advantageously cylindrical and arranged so that they surround each other concentrically. The inner tube and also the tube elements are preferably made of ceramic material, in particular one which is resistant to temperature shock and change and is also resistant to chlorine gas.

In weiterer Ausgestaltung der Erfindung sind die von dem Innenrohr und den es umschließenden Rohren gebildeten Rohrelemente zu einem Rohrpaket verbunden, das sich als Baueinheit aus der Wanne herausheben und in die Wanne einsetzen läßt. Dabei können die Rohrelemente auch mit der abnehmbaren Abdeckung der Wanne zu einer Baueinheit verbunden werden. Weiterhin empfiehlt es sich, die Rohrelemente an ihrem oberen Ende mit leicht auswechselbar angeordneten Austauschringen zu versehen, so daß, wenn diese Teile z.B. durch Krätzeeinflüsse beschädigt sind, leicht ausgewechselt werden können. Die siphon-labyrinthartige Verbindung der Kammern kann auch durch Mantelöffnungen der Rohrelemente gebildet werden.In a further embodiment of the invention, the tube elements formed by the inner tube and the tubes surrounding it connected to a tube package that can be lifted out of the tub as a structural unit and inserted into the tub. The tubular elements can also be connected to the removable cover of the tub to form a structural unit. Furthermore, it is advisable to provide the tubular elements at their upper end with easily exchangeable replacement rings, so that if these parts are damaged, for example by dross, they can be easily replaced. The siphon-labyrinthine connection of the chambers can also be formed by jacket openings in the tubular elements.

Im übrigen empfiehlt es sich, die gesamte Reinigungsvorrichtung so auszubilden, daß sie um eine Querachse kippbar ist. Bei entfernter Abdeckung kann daher durch Kippen der Reinigungsvorrichtung ein rascher Legierungswechsel vorgenommen werden. Um in einer Gießerei mit möglichst wenigen Reinigungsvorrichtungen auskommen zu können, wird die gesamte Reinigungsvorrichtung zweckmäßig mobil gestaltet.For the rest, it is advisable to design the entire cleaning device so that it can be tilted about a transverse axis. When the cover is removed, the alloy can be quickly changed by tilting the cleaning device. In order to be able to make do with as few cleaning devices as possible in a foundry, the entire cleaning device is expediently designed to be mobile.

Die Erfindung wird nachfolgend im Zusammenhang mit dem in der Zeichnung in schematischer Vereinfachung gezeigten Ausführungsbeispiel näher erläutert, wobei die Zeichnung eine erfindungsgemäße Reinigungsvorrichtung im Vertikalschnitt zeigt.The invention is explained in more detail below in connection with the exemplary embodiment shown in the drawing in a schematic simplification, the drawing showing a cleaning device according to the invention in vertical section.

Die dargestellte Reinigungsvorrichtung besteht aus einem Tiegel bzw. einer Wanne 1, die z.B. aus chromlegiertem Gußeisen gefertigt ist und mittels einer abnehmbaren Abdeckung 2 verschließbar ist, so daß eine für den Reinigungsbetrieb geschlossene Reinigungsbox gebildet wird. Um ein Erstarrren der Schmelze während des Reinigungsvorgangs zu vermeiden, ist am Außenmantel und im Bodenbereich der Wanne 1 sowie auch für den abnehmbaren Deckel ein Heizsystem mit elektrischen Heizelementen 3 vorgesehen, die sich in einer die Wanne im Mantel- und Bodenbereich umschließenden Isolierung 4 befinden, die von einem Ofenmantel 30 umschlossen ist. Die Isolierung 4 besteht zweckmäßig aus einem Feuerfestmaterial od.dgl.The cleaning device shown consists of a crucible or a tub 1, which is made, for example, of chromium-alloyed cast iron and can be closed by means of a removable cover 2, so that a cleaning box which is closed for the cleaning operation is formed. In order to prevent the melt from solidifying during the cleaning process, a heating system with electrical heating elements 3 is provided on the outer jacket and in the bottom area of the tub 1 and also for the removable lid, which are located in an insulation 4 surrounding the tub in the jacket and bottom area, which is enclosed by a furnace jacket 30. The insulation 4 suitably consists of a refractory material or the like.

In der Wanne 1 befinden sich Einbauten, die von Rohrelementen gebildet sind und ein System von sich umschließenden Kammern bilden, die für den Durchfluß der Schmelze wechselnd im Kopf- bzw. Fußbereich der Rohrelemente siphon-labyrinthartig miteinander verbunden sind. Die Einbauten werden von einem in der Vertikalachse der Wanne 1 angeordneten Innenrohr 5 und mehreren, im gezeigten Ausführungsbeispiel vier das Innenrohr 5 konzentrisch mit etwa gleichen Radialabständen umschließenden Rohrelementen 6 bis 9 gebildet. Das Innenrohr 5 bildet dabei in der Wanne 1 eine Zentralkammer 10, die von mehreren ringförmigen Kammern, nämlich den Zwischenkammern 11 bis 14 und der Außenkammer 15 umschlossen ist. Die Zentralkammer 10 ist nur in ihrem Fußbereich bei 16 mit der sie umschließenden Zwischenkammer 11 für den Schmelzedurchfluß verbunden, während die Zwischenkammer 11 nur im Kopfbereich bei 17 mit der benachbarten Zwischenkammer 12, letztere nur im Fußbereich bei 18 mit der folgenden Zwischenkammer 13 und diese nur im Kopfbereich bei 19 mit der Zwischenkammer 14 für den Schmelzedurchfluß in Verbindung steht, wobei die Außenkammer 15 nur im Fußbereich bei 20 mit der benachbarten Zwischenkammer 14 verbunden ist. Auf diese Weise wird von den Rohrelementen 5 bis 9 das zusammenhängende siphon-labyrinthartige Kanalsystem gebildet. Die Durchflußöffnungen 16 bis 20 werden zweckmäßig von Mantelöffnungen in den Endbereichen der verschiedenen Rohrelemente 5 bis 9 gebildet. Sie können aber auch dadurch gebildet werden, daß die Rohrelemente so gegeneinander axial versetzt sind, daß sie im Abstand vor dem Boden der Wanne bzw. der Abdeckung enden.In the tub 1 there are internals which are formed by tubular elements and form a system of enclosing chambers which are connected to one another in the head or foot region of the tubular elements in a siphon-labyrinth-like manner for the flow of the melt. The internals are formed by an inner tube 5 arranged in the vertical axis of the tub 1 and a plurality of tube elements 6 to 9 concentrically enclosing the inner tube 5 with approximately the same radial spacings in the exemplary embodiment shown. The inner tube 5 forms in the tub 1 a central chamber 10 which is surrounded by a plurality of annular chambers, namely the intermediate chambers 11 to 14 and the outer chamber 15. The central chamber 10 is connected only in its foot area at 16 to the intermediate chamber 11 surrounding it for melt flow, while the intermediate chamber 11 only in the head area at 17 with the adjacent intermediate chamber 12, the latter only in the foot area at 18 with the following intermediate chamber 13 and this only in the head area at 19 is connected to the intermediate chamber 14 for the melt flow, the outer chamber 15 being connected to the adjacent intermediate chamber 14 only in the foot area at 20. In this way, the coherent siphon-labyrinth-like channel system is formed by the tube elements 5 to 9. The flow openings 16 to 20 are expediently formed by jacket openings in the end regions of the various tubular elements 5 to 9. But they can also be formed in that the tubular elements are axially offset from one another in such a way that they end at a distance from the bottom of the tub or the cover.

Die Rohrelemente 5 bis 9 sind zweckmäßig zylindrisch ausgebildet und so angeordnet, daß sie sich konzentrisch umschließen. Statt dessen könnten die Rohrelemente aber auch eine von der Zylinderform abweichende Umrißform aufweisen. Vorzugsweise bestehen die Rohrelemente aus einem Keramikmaterial, insbesondere einem solchen, das gegenüber Temperaturschock und auch gegen Chlorgas beständig ist. Die Rohrelemente 5 bis 9 werden zweckmäßig zu einem Rohrpaket miteinander verbunden, das sich als Baueinheit nach oben aus der Wanne 1 herausheben bzw. als Baueinheit von oben in die Wanne einsetzen läßt. Dabei können die Rohrelemente auch mit der Abdeckung 2 verbunden sein, so daß sie sich nach Lösen der Abdeckung mit dieser aus der Wanne 1 herausheben lassen.The tubular elements 5 to 9 are expediently cylindrical and arranged so that they surround each other concentrically. Instead, the tubular elements could also have an outline shape deviating from the cylindrical shape. The tubular elements preferably consist of a ceramic material, in particular one which is resistant to temperature shock and also to chlorine gas. The tubular elements 5 to 9 are expediently connected to one another to form a tube package which can be lifted up out of the tub 1 as a structural unit or inserted into the tub as a structural unit from above. The tubular elements can also be connected to the cover 2 so that they can be lifted out of the tub 1 after the cover has been released.

Die Zuführung 21 für die zu reinigende Schmelze ist der Zentralkammer 10 zugeordnet und befindet sich am Kopf der Zentralkammer. Sie besteht aus einem an der Abdeckung 2 angeordneten Füllstutzen od.dgl. Die Spülgaszuführung ist ebenfalls der Zentralkammer 10 zugeordnet. Sie ist so ausgebildet, daß das von außen zugeführte Spülgas im unteren Bereich in die Zentralkammer 10 austritt und daher im Gegenstrom zu der in der Zentralkammer 10 befindlichen Schmelze in dieser aufsteigt. Die Spülgaszuführung wird von einem von oben in die Zentralkammer 10 eintauchenden, mit der Abdeckung 2 verbundenen Tauchrohr 22 gebildet, welches an seinem unteren Ende den Spülgasaustritt aufweist. In einer bevorzugten Ausführungsform kann das Tauchrohr 22 dabei den Stator eines an seinem unteren Ende angeordneten Rotors 23 bilden, der ein die in der Zentralkammer 10 befindliche Schmelze umrührendes und durchwirbelndes Rührelement darstellt, das von einem oberhalb der Abdeckung 2 angeordneten Motor 28 angetrieben wird. Das zugeführte Spülgas kann, wie bekannt, uber Drehdüsen, die mit dem Rotor 23 umlaufen, in die Schmelze austreten.The feed 21 for the melt to be cleaned is assigned to the central chamber 10 and is located at the head of the central chamber. It consists of a filler neck or the like arranged on the cover 2. The purge gas supply is also assigned to the central chamber 10. It is designed so that the purge gas supplied from the outside exits in the lower region into the central chamber 10 and therefore rises in the countercurrent to the melt in the central chamber 10. The purge gas supply is formed by an immersion tube 22, which dips into the central chamber 10 from above and is connected to the cover 2 and which has the purge gas outlet at its lower end. In a preferred embodiment, the immersion tube 22 can form the stator of a rotor 23 arranged at its lower end, which represents a stirring element which stirs and swirls the melt located in the central chamber 10 and is driven by a motor 28 arranged above the cover 2. As is known, the supplied purge gas can escape into the melt via rotating nozzles which rotate with the rotor 23.

Die Ableitung für die gereinigte Schmelze ist der ringförmigen Außenkammer 15 zugeordnet. Sie besteht aus einem im Kopfbereich in die Außenkammer 15 mündenden Ableitungsrohr 24, das durch den Mantel der Wanne 1 und deren Isolierung 4 quer hindurchgeführt ist.The discharge line for the cleaned melt is assigned to the annular outer chamber 15. It consists of a discharge pipe 24 which opens into the outer chamber 15 in the head region and which crosses through the casing of the tub 1 and its insulation 4 is passed through.

Die Abdeckung 2 weist in ihrem Umfangsbereich oberhalb der Kammern 11 bis 15 eine Krätze-Entnahmeöffnung 25 auf, die mittels einer entfernbaren Verschlußplatte 26 od.dgl. verschlossen wird.The cover 2 has in its peripheral region above the chambers 11 to 15 a dross removal opening 25 or the like by means of a removable closure plate 26. is closed.

Die Reinigung der Schmelze mit Hilfe des Spülgases erfolgt in an sich bekannter Weise einerseits durch Flotation der Verunreinigungen und andererseits dadurch, daß durch das Spülgas der Wasserstoffpartialdruck in der Schmelze herabgesetzt wird, so daß der Wasserstoff durch Desorption in den in der Schmelze aufsteigenden Spülgasblasen aus der Schmelze entfernt wird. Die nichtmetallischen Verunreinigungen steigen mit den Gasblasen in der Schmelze auf und lagern sich im Bereich der Kammern 11 bis 14 als Krätzeschicht 27 auf der Schmelzbadoberfläche ab, so daß sie bei geöffneter Krätze-Entnahmeöffnung 25 entfernt werden können. Als Spülgas wird ein Inertgas, im allgemeinen Stickstoff und/oder Argon, verwendet, dem Chlorgas beigefügt werden kann, um in der verunreinigten Schmelze enthaltene Kali- oder Erdalkalimetalle, wie insbesondere Natrium, Lithium, Magnesium und Calcium, zu Chloriden umzusetzen, die durch die Flotationswirkung in die Krätze 27 eingehen und mit dieser entfernt werden können. Es besteht die Möglichkeit, der aufschwimmenden Krätze 27 ein Abdecksalz als Schmelzmittel zuzusetzen, das die aufschwimmenden Verunreinigungen zu einer geschlossenen Krätzeschicht bindet.The purification of the melt with the aid of the purge gas takes place in a manner known per se, on the one hand, by flotation of the impurities and, on the other hand, in that the hydrogen partial pressure in the melt is reduced by the purge gas, so that the hydrogen is desorbed from the purge gas bubbles rising in the melt Melt is removed. The non-metallic impurities rise with the gas bubbles in the melt and are deposited in the area of the chambers 11 to 14 as a dross layer 27 on the surface of the melt pool, so that they can be removed when the dross removal opening 25 is open. An inert gas, generally nitrogen and / or argon, is used as the flushing gas, to which chlorine gas can be added in order to convert potassium or alkaline earth metals, such as in particular sodium, lithium, magnesium and calcium, contained in the contaminated melt to chlorides, which are converted by the Flotation effect go into the scabies 27 and can be removed with this. It is possible to add a covering salt as a melting agent to the floating scabies 27, which binds the floating impurities to form a closed scabbing layer.

Die beschriebene Reinigungsvorrichtung kann im kontinuierlichen Betrieb, also mit kontinuierlichem Durchlauf der Schmelze durch die Reinigungsvorrichtung arbeiten. Da die von oben in die Zentralkammer 10 eingeführte Schmelze im Gegenstrom von dem im unteren Bereich in die Zentralkammer 10 eingeführten Spülgas durchströmt wird, ergibt sich eine intensive Beaufschlagung der Schmelze durch das Spülgas, das feinperlig durch die Schmelze aufsteigt. Durch das angetriebene Rührelement 23 wird die Schmelze zusätzlich umgerührt bzw. in Turbulenz gebracht, wodurch der Spülgaskontakt mit der Schmelze weiter verbessert wird. Die Schmelze strömt durch das siphon-labyrinthartige Kammersystem 11 bis 15 mit ständig abnehmender Fließgeschwindigkeit, so daß hier das Spülgas und die Krätzebestandteile ausreichend Gelegenheit bekommen, aus der Schmelze zu entweichen bzw. sich an der Schmelzbadoberfläche abzusetzen. Über die Ableitung 24 verläßt die gereinigte Schmelze im Kopfbereich der Außenkammer 15 die geschlossene Reinigungskammer. Am äußeren Rohrelement kann hierbei ein Auffangkragen od.dgl. vorgesehen werden, um einen gleichmäßigen Überlauf der schmelze über den Umfang des letzten Rohres zu gewährleisten. Aus dem Auffangkragen läuft dann die gereinigte Schmelze z.B. über eine Sammelrinne zur nachgeschalteten Gießmaschine. Abgase, wie insbesondere Chlor, können durch die kompakte Bauweise der Reinigungsvorrichtung auf kleinem Raum abgezogen und umweltfreundlich in einer Al₂O₃-Schüttung zu AlCl₃ umgesetzt werden.The cleaning device described can work in continuous operation, that is to say with continuous passage of the melt through the cleaning device. Since the melt introduced from above into the central chamber 10 flows in countercurrent from the flushing gas introduced into the lower region into the central chamber 10, there is an intensive exposure of the melt to the flushing gas, which ascending through the melt. The melt is additionally stirred or brought into turbulence by the driven stirring element 23, whereby the purging gas contact with the melt is further improved. The melt flows through the siphon-labyrinth-like chamber system 11 to 15 with a continuously decreasing flow rate, so that here the flushing gas and the dross components have sufficient opportunity to escape from the melt or to settle on the surface of the melt pool. Via the discharge line 24, the cleaned melt leaves the closed cleaning chamber in the head region of the outer chamber 15. A collecting collar or the like can be placed on the outer tubular element. be provided to ensure a uniform overflow of the melt over the circumference of the last tube. The cleaned melt then runs out of the collecting collar, for example via a collecting trough, to the downstream casting machine. Exhaust gases, such as chlorine in particular, can be drawn off in a small space due to the compact design of the cleaning device and implemented in an environmentally friendly manner in an Al₂O₃ bed to AlCl₃.

Es empfiehlt sich, die verschiedenen Rohrelemente 5 bis 9 an ihren oberen Enden jeweils mit einem leicht auswechselbaren Austauschring zu versehen, so daß etwaige durch Krätzeeinflüsse beschädigte Oberteile der Rohre durch Wechsel der Austauschringe ersetzt werden können, ein vollständiger Austausch der einzelnen Rohre also nicht erforderlich ist.It is advisable to provide the different pipe elements 5 to 9 at their upper ends with an easily replaceable exchange ring, so that any top parts of the pipes damaged by dross can be replaced by changing the exchange rings, so a complete exchange of the individual pipes is not necessary .

Die gesamte Reinigungsvorrichtung wird zweckmäßig mobil gestaltet, um innerhalb einer Gießerei mit möglichst wenigen Reinigungsgeräten auskommen zu können. Ferner empfiehlt es sich, das Reinigungsgerät so auszubilden, daß es um eine Querachse kippbar ist, um bei Bedarf einen schnellen Legierungswechsel vornehmen zu können.The entire cleaning device is expediently designed to be mobile in order to be able to use as few cleaning devices as possible within a foundry. It is also advisable to design the cleaning device in such a way that it can be tilted about a transverse axis in order to be able to change the alloy quickly if necessary.

Es versteht sich, daß die Anzahl der in der Wanne 1 angeordneten Rohrelemente unterschiedlich sein kann. Gegebenenfalls kann auch nur ein zentrales Rohrelement 5 vorgesehen sein, obwohl die Anordnung mehrerer sich umschließender Rohrelemente vorzuziehen ist.It is understood that the number of tubular elements arranged in the tub 1 can be different. If necessary, only one central tube element 5 can also be provided, although it is preferable to arrange several tubular elements that are enclosed.

Claims (21)

Vorrichtung zum Reinigen von NE-Metallschmelzen, insbesondere Aluminiumschmelzen, durch Flotation der Verunreinigungen und Entgasung durch Herabsetzung des Wasserstoffpartialdrucks in der Schmelze, gegebenenfalls in Verbindung mit einer Chlorierung, bestehend aus einer mit einem Heizsystem versehenen, durch eine entfernbare Abdeckung geschlossenen Wanne od.dgl., einer Zuführung für die zu reinigende Schmelze und einer Ableitung für die gereinigte Schmelze und aus einer das Spülgas im unteren Bereich der Wanne in die Schmelze einführenden Spülgaszuführung, dadurch gekennzeichnet, daß in der Wanne (1) eine von einem Innenrohr (5) gebildete Zentralkammer (10) angeordnet ist, die in ihrem Endbereich mit dem Wannenraum am Umfang des Innenrohres (5) verbunden ist, und daß die Spülgaszuführung (22) sowie die Zuführung (21) für die zu reinigende Schmelze der Zentralkammer (10) zugeordnet ist, während die Ableitung (24) für die gereinigte Schmelze dem die Zentralkammer (10) umschließenden Wannenraum zugeordnet ist.Device for cleaning non-ferrous metal melts, in particular aluminum melts, by flotation of the contaminants and degassing by reducing the hydrogen partial pressure in the melt, optionally in connection with chlorination, consisting of a tub or the like provided with a heating system and closed by a removable cover. , a feed for the melt to be cleaned and a discharge for the cleaned melt and from a purge gas feeder which introduces the purge gas into the melt in the lower region of the tub, characterized in that in the tub (1) a central chamber formed by an inner tube (5) (10) is arranged, which is connected in its end region to the tub space on the circumference of the inner tube (5), and that the purge gas supply (22) and the supply (21) for the melt to be cleaned are assigned to the central chamber (10), while the derivation (24) for the cleaned melt which the central chamber (10) scanned enclosing tub space is assigned. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß das Innenrohr (5) von weiteren Rohrelementen (6 bis 9) umschlossen ist, die in der Wanne (1) ein System von sich und die Zentralkammer (10) umschließenden Kammern (11 bis 15) bilden, welche im Kopf- bzw. Fußbereich der Rohrelemente siphonlabyrinthartig miteinander verbunden sind, wobei die Ableitung (24) für die gereinigte Schmelze der ringförmigen Außenkammer (15) zugeordnet ist.Device according to claim 1, characterized in that the inner tube (5) is enclosed by further tube elements (6 to 9) which form a system of chambers and enclosing the central chamber (10) in the trough (1) , which are connected to each other like a siphon labyrinth in the head or foot region of the tubular elements, the discharge line (24) for the cleaned melt being assigned to the annular outer chamber (15). Vorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Zentralkammer (10) nur in ihrem Fußbereich mit dem sie umschließenden Wannenraum bzw. mit der sie umschließenden Zwischenkammer (11) für den Schmelzedurchfluß verbunden ist.Device according to claim 1 or 2, characterized in that the central chamber (10) is only connected in its foot area to the tub space enclosing it or to the intermediate chamber (11) enclosing it for the melt flow. Vorrichtung nach Anspruch 2 oder 3, dadurch gekennzeichnet, daß die ringförmige Außenkammer (15) nur in ihrem Fußbereich mit der ihr benachbarten Zwischenkammer (14) für den Schmelzedurchfluß verbunden ist.Device according to claim 2 or 3, characterized in that the annular outer chamber (15) is connected to the intermediate chamber (14) for melt flow only in its foot region. Vorrichtung nach einem der Ansprüche 2 bis 4, dadurch gekennzeichnet, daß die Rohrelemente (5 bis 9) zylindrisch ausgebildet sind und sich konzentrisch umschließen.Device according to one of claims 2 to 4, characterized in that the tubular elements (5 to 9) are cylindrical and surround each other concentrically. Vorrichtung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Zuführung (21) für die zu reinigende Schmelze am Kopf der Zentralkammer (10) angeordnet ist.Device according to one of claims 1 to 5, characterized in that the feed (21) for the melt to be cleaned is arranged at the head of the central chamber (10). Vorrichtung nach Anspruch 6, dadurch gekennzeichnet, daß die Zuführung (21) für die zu reinigende Schmelze aus einem an der Abdeckung (2) angeordneten Füllstutzen od.dgl. besteht.Apparatus according to claim 6, characterized in that the feed (21) for the melt to be cleaned from a filler neck or the like arranged on the cover (2). consists. Vorrichtung nach einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, daß die Spülgaszuführung aus einem von oben in die Zentralkammer (10) eintauchenden, vorzugsweise mit der Abdeckung (2) verbundenen Tauchrohr (22) mit Spülgasaustritt an seinem unteren Ende besteht.Device according to one of claims 1 to 7, characterized in that the flushing gas supply consists of an immersion tube (22) which dips into the central chamber (10) from above and is preferably connected to the cover (2) and has a flushing gas outlet at its lower end. Vorrichtung nach Anspruch 8, dadurch gekennzeichnet, daß das Tauchrohr (22) am unteren Ende ein angetriebenes Rührorgan (23) aufweist.Apparatus according to claim 8, characterized in that the immersion tube (22) has a driven stirring element (23) at the lower end. Vorrichtung nach einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, daß das bzw. die Rohrelemente (5 bis 9) aus Keramikmaterial bestehen.Device according to one of claims 1 to 9, characterized in that the pipe element (s) (5 to 9) consist of ceramic material. Vorrichtung nach einem der Ansprüche 2 bis 10, dadurch gekennzeichnet, daß die Rohrelemente (5 bis 9) zu einem aus der Wanne (1) heraushebbaren Rohrpaket verbunden sind.Device according to one of claims 2 to 10, characterized in that the tube elements (5 to 9) are connected to a tube package which can be lifted out of the trough (1). Vorrichtung nach Anspruch 11, dadurch gekennzeichnet, daß die Rohrelemente (5 bis 9) mit der abnehmbaren Abdeckung (2) zu einer Baueinheit verbunden sind.Device according to claim 11, characterized in that the tubular elements (5 to 9) are connected to the removable cover (2) to form a structural unit. Vorrichtung nach einem der Ansprüche 1 bis 12, dadurch gekennzeichnet, daß an der Abdeckung (2) in deren Umfangsbereich eine verschließbare Krätze-Entnahmeöffnung (25) angeordnet ist.Device according to one of claims 1 to 12, characterized in that a closable dross removal opening (25) is arranged on the cover (2) in the peripheral region thereof. Vorrichtung nach einem der Ansprüche 1 bis 13, dadurch gekennzeichnet, daß die Ableitung (24) für die gereinigte Schmelze im Kopfbereich der die Innenkammer (10) umschließenden Außenkammer angeordnet ist.Device according to one of claims 1 to 13, characterized in that the discharge line (24) for the cleaned melt is arranged in the head region of the outer chamber surrounding the inner chamber (10). Vorrichtung nach Anspruch 14, dadurch gekennzeichnet, daß die Ableitung (24) aus einem im Kopfbereich in die Außenkammer mündenden, durch den Mantel der Wanne (1) quer hindurchgeführten Ableitungsrohr od.dgl. besteht.Apparatus according to claim 14, characterized in that the discharge pipe (24) from a discharge pipe or the like which leads into the outer chamber in the head region and runs transversely through the jacket of the trough (1). consists. Vorrichtung nach einem der Ansprüche 1 bis 15, dadurch gekennzeichnet, daß das Heizsystem (3) als Außenbeheizung am Mantel und zweckmäßig auch am Boden der Wanne (1) in einer Feuerfestauskleidung (4) des Ofenmantels angeordnet ist.Device according to one of claims 1 to 15, characterized in that the heating system (3) is arranged as external heating on the casing and expediently also on the bottom of the trough (1) in a refractory lining (4) of the furnace casing. Vorrichtung nach einem der Ansprüche 1 bis 16, dadurch gekennzeichnet, daß die Rohrelemente (5 bis 9) am oberen Ende mit leicht auswechselbaren Austauschringen versehen sind.Device according to one of claims 1 to 16, characterized in that the tubular elements (5 to 9) are provided at the upper end with easily exchangeable replacement rings. Vorrichtung nach einem der Ansprüche 2 bis 17, dadurch gekennzeichnet, daß die siphon-labyrinthartige Verbindung der Kammern (10 bis 15) durch Mantelöffnungen der Rohrelemente (5 bis 9) gebildet ist.Device according to one of claims 2 to 17, characterized in that the siphon-labyrinth-like connection of the chambers (10 to 15) is formed by jacket openings in the tubular elements (5 to 9). Vorrichtung nach einem der Ansprüche 1 bis 18, dadurch gekennzeichnet, daß sie um eine Querachse kippbar gelagert ist.Device according to one of claims 1 to 18, characterized in that it is mounted such that it can be tilted about a transverse axis. Vorrichtung nach einem der Ansprüche 1 bis 19, dadurch gekennzeichnet, daß sie als mobile Baueinheit ausgebildet ist.Device according to one of claims 1 to 19, characterized in that it is designed as a mobile structural unit. Vorrichtung nach einem der Ansprüche 1 bis 20, dadurch gekennzeichnet, daß die abnehmbare Abdeckung (2) eine Beheizung aufweist.Device according to one of claims 1 to 20, characterized in that the removable cover (2) has a heater.
EP91115522A 1990-09-17 1991-09-13 Apparatus for the purification of molten non-ferrous metals, in particular molten aluminium. Expired - Lifetime EP0476534B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4029396 1990-09-17
DE4029396A DE4029396A1 (en) 1990-09-17 1990-09-17 DEVICE FOR CLEANING NE-METAL MELTS, ESPECIALLY ALUMINUM MELTS

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EP0476534A1 true EP0476534A1 (en) 1992-03-25
EP0476534B1 EP0476534B1 (en) 1995-06-21

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EP91115522A Expired - Lifetime EP0476534B1 (en) 1990-09-17 1991-09-13 Apparatus for the purification of molten non-ferrous metals, in particular molten aluminium.

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EP (1) EP0476534B1 (en)
JP (1) JPH04232218A (en)
AT (1) ATE124091T1 (en)
CA (1) CA2051590A1 (en)
DE (2) DE4029396A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0665198A1 (en) * 1994-01-27 1995-08-02 Foseco International Limited Impact resistant oxidation protection for graphite parts
CN101768671B (en) * 2009-01-06 2012-08-08 上海电机学院 Vertex angle combined blowing type aluminum melt degassing method and device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19703062C1 (en) * 1997-01-28 1998-03-26 Conradty Mechanical & Electric Dispersing apparatus for gases in metal melt
CN101994014A (en) * 2010-12-08 2011-03-30 西南铝业（集团）有限责任公司 On-line purifying and degassing unit

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3893019A (en) * 1970-02-16 1975-07-01 Texas Instruments Inc Variable power control adapter
GB2009247A (en) * 1977-12-01 1979-06-13 Aluminum Co Of America Skim removal
US4427185A (en) * 1982-11-26 1984-01-24 Atlantic Richfield Company Method and apparatus for gaseous cleaning of aluminum
EP0065854B1 (en) * 1981-05-19 1985-08-28 Alcan International Limited Removal of alkali metals and alkaline earth metals from molten aluminium
EP0332292A1 (en) * 1988-02-24 1989-09-13 Foseco International Limited Rotary device, apparatus and method for treating molten metal
GB2220424A (en) * 1988-07-05 1990-01-10 Christopher John English Degassing and cleaning system for molten metals

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3893019A (en) * 1970-02-16 1975-07-01 Texas Instruments Inc Variable power control adapter
GB2009247A (en) * 1977-12-01 1979-06-13 Aluminum Co Of America Skim removal
EP0065854B1 (en) * 1981-05-19 1985-08-28 Alcan International Limited Removal of alkali metals and alkaline earth metals from molten aluminium
US4427185A (en) * 1982-11-26 1984-01-24 Atlantic Richfield Company Method and apparatus for gaseous cleaning of aluminum
EP0332292A1 (en) * 1988-02-24 1989-09-13 Foseco International Limited Rotary device, apparatus and method for treating molten metal
GB2220424A (en) * 1988-07-05 1990-01-10 Christopher John English Degassing and cleaning system for molten metals

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0665198A1 (en) * 1994-01-27 1995-08-02 Foseco International Limited Impact resistant oxidation protection for graphite parts
CN101768671B (en) * 2009-01-06 2012-08-08 上海电机学院 Vertex angle combined blowing type aluminum melt degassing method and device

Also Published As

Publication number Publication date
DE4029396A1 (en) 1992-03-19
DE59105777D1 (en) 1995-07-27
EP0476534B1 (en) 1995-06-21
CA2051590A1 (en) 1992-03-18
ATE124091T1 (en) 1995-07-15
JPH04232218A (en) 1992-08-20

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