EP1105234B1 - Method and device for the continuous degassing of molten metals - Google Patents

Method and device for the continuous degassing of molten metals Download PDF

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Publication number
EP1105234B1
EP1105234B1 EP99944261A EP99944261A EP1105234B1 EP 1105234 B1 EP1105234 B1 EP 1105234B1 EP 99944261 A EP99944261 A EP 99944261A EP 99944261 A EP99944261 A EP 99944261A EP 1105234 B1 EP1105234 B1 EP 1105234B1
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Prior art keywords
chamber
degassing
casting
bath
pipe
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EP99944261A
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German (de)
French (fr)
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EP1105234A1 (en
Inventor
Hans Bebber
Juan FÄHNRICH
Günter PHILLIPPS
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Induga Industrieofen und Giesserei-Anlagen & Co KG GmbH
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Induga Industrieofen und Giesserei-Anlagen & Co KG GmbH
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10Supplying or treating molten metal
    • B22D11/11Treating the molten metal
    • B22D11/113Treating the molten metal by vacuum treating
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10Handling in a vacuum
    • 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
    • C22B9/04Refining by applying a vacuum

Definitions

  • the invention relates to an apparatus and a method according to the preambles of claims 1 and 6.
  • the so-called secondary metallurgy is the degassing of Metal melting basically under the keyword vacuum treatment known. This is a post-treatment of molten metal under greatly reduced pressure understood on the Insight is based on the fact that when the external pressure is lowered, the pressure in the Metal melt dissolved gases, especially hydrogen, escape. In the case of partial degassing that comes into consideration here becomes only part of the liquid melt at a time exposed to vacuum, either by vacuum circulation degassing or a vacuum lifter degassing.
  • a preferred field of application of the methods presented is the production of oxygen-free copper (OF copper), in addition to low oxygen levels in the order of magnitude from 1 to 3 ppm also typically low hydrogen contents must be reached below 1 ppm.
  • This takes advantage of that the hydrogen solubility in copper with falling Pressure decreases and therefore the one normally dissolved in copper Escape hydrogen from the metal under vacuum conditions can without increasing the oxygen content again.
  • This The device has a supplied molten liquid Containers containing metals and one for degassing Vacuum chamber, in which an inflow for the molten First chamber containing metals protrudes a riser pipe, the upper end of which opens into the vacuum chamber, the Bottom has a drain opening connected to a downpipe is its lower end forming an outlet opening into a second chamber, designed as a casting chamber, into an outlet nozzle opens and is characterized in that the riser pipe and the downpipe are provided with a heater.
  • the first and the second chamber are preferably spatially located with each other and have a dam that the Divides chambers in the lower area into two bath chambers, the Riser pipe and the down pipe in different areas below the upper edge of the dam.
  • a dam that the Divides chambers in the lower area into two bath chambers, the Riser pipe and the down pipe in different areas below the upper edge of the dam.
  • the riser pipe and the down pipe are preferably each parallel arranged vertically to each other.
  • the task related to the procedure is determined by the measures solved according to claim 6, wherein the molten metal from a first chamber via a riser pipe with one below the bath level lying inlet opening in a as a degassing room serving vacuum chamber transferred and from there due to gravity into a downpipe with a lower outlet opening, which is preferably lies below the bath level in the casting chamber, in the casting chamber is discharged.
  • This process technology has the Advantage that the molten metal, which transfers into the casting chamber is previously complete during the previous run of the Vacuum chamber has been degassed. A mix of already degassed molten metal with an untreated molten metal is thus avoided.
  • the bath level in the first chamber and the casting chamber in different height levels.
  • the riser pipe and the downpipe is a connection between the two chambers created according to the type of communicating tubes works, according to the height difference between the higher bath level in the first chamber and the bath level in a metal melt flow is maintained in the casting chamber.
  • the molten metal can continuously or from the casting chamber be drained discontinuously.
  • the first and the second chamber spatially connected and in lower area divided into two bath chambers by a dam.
  • the bathroom mirrors are located in the first and second chamber below the top edge of the dam, the metal melt from the first chamber via the riser pipe into the vacuum chamber and from there through the downpipe into the casting chamber.
  • the vacuum chamber e.g. in the event of a pump defect, or even in cases where degassing is not required the bathroom mirror is set so that it is above the edge of the said dam lies, so that in the first and the second chamber forms a common continuous bathroom mirror and that molten metal bypassing the vacuum chamber directly into the casting chamber.
  • the degassing rate is very dependent on the temperature, which is why according to a further embodiment of the invention the molten metal is heated inductively, which makes it possible to control the degassing.
  • the length of stay the molten metal in the vacuum chamber over the Pressure regulated in this vacuum chamber is a further embodiment of the invention.
  • the system shown has a pouring chamber 10 into which the liquid metal continuously from an upstream Storage oven is filled. Runs out of this pouring chamber 10 the molten metal through an inductor channel or Inductor channels 11 in the first chamber 20, in which a vertical arranged riser 15 protrudes so that the riser with its lower opening is below the bathroom mirror.
  • the Riser pipe 15 and the down pipe 16, which in a casting chamber 13th protrudes and its lower opening also under the one there Bathroom mirrors are in the form of connecting pieces of the floor Vacuum chamber 17 formed by means of a nozzle 18 a pump can be evacuated.
  • the casting chamber 13 and the first Chamber 20 are separated from one another by a dam 12.
  • the bath level in the pouring chamber 10 or the first Chamber 20 can be set between the limits 21 and 22 the molten metal as shown in Fig. 1 of the first chamber 20 only via the riser pipe Vacuum chamber 17 and the downpipe get into the casting chamber 13.
  • In the entry area there is still a Inductor, by means of which the flowing molten metal is heated can be. With this inductor is an ideal means to control the degassing, which is strongly temperature-dependent is.
  • Burner 19 provided which the riser pipe 15 and the down pipe 16 heat. Compared to inductive heating, this has Burner heating has the advantage that it preheats the Entire chamber including the risers allowed.
  • the Casting chamber 13 also has a nozzle 14, through which the molten Metal can be drained.
  • the degassed metal To protect against air ingress, the casting chamber 13 is over a weir 24 separated from the rest of the furnace atmosphere, so that the Casting chamber is hermetically sealed to the outside. The weir ends with its lower edge below the bathroom mirror in the Casting chamber.
  • the device according to the invention works as follows:
  • the pouring chamber 10 is filled with molten material via an inlet Metal continuously filled, with the bathroom mirror between the boundary lines 21 and 22.
  • the Vacuum chamber 17 set a negative pressure, which causes the molten metal rises over the riser pipe 15, in the vacuum chamber 17 is degassed.
  • the molten metal flows through the downpipe 16 beyond the dam 12 into the casting chamber 13 as long as the bath level there is below the level the bath level of the pouring chamber.
  • the burners 19 are operated for adequate temperature control to care.
  • the level of the bath level 27 in the Container 22 corresponds to the static pressure in the Vacuum chamber 17.
  • the bath level in the first chamber 20 is adjusted so that the Dam 12 is flooded so that the molten metal can get directly into the casting chamber 13.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Continuous Casting (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Furnace Details (AREA)

Description

Die Erfindung betrifft eine Vorrichtung und ein Verfahren gemäß den Oberbegriffen der Ansprüche 1 und 6.The invention relates to an apparatus and a method according to the preambles of claims 1 and 6.

Aus der sogenannten Sekundärmetallurgie ist die Entgasung von Metallschmelzen grundsätzlich unter dem Schlagwort Vakuumbehandlung bekannt. Hierunter wird eine Metallschmelzennachbehandlung unter stark vermindertem Druck verstanden, die auf der Erkenntnis beruht, daß bei abgesenktem Außendruck die in der Metallschmelze gelösten Gase, insbesondere Wasserstoff, entweichen. Bei der hier gattungsgemäß in Betracht kommenden Teilmengenentgasung wird jeweils nur ein Teil der flüssigen Schmelze dem Vakuum ausgesetzt, entweder durch eine Vakuum-Umlaufentgasung oder eine Vakuum-Heberentgasung.The so-called secondary metallurgy is the degassing of Metal melting basically under the keyword vacuum treatment known. This is a post-treatment of molten metal under greatly reduced pressure understood on the Insight is based on the fact that when the external pressure is lowered, the pressure in the Metal melt dissolved gases, especially hydrogen, escape. In the case of partial degassing that comes into consideration here becomes only part of the liquid melt at a time exposed to vacuum, either by vacuum circulation degassing or a vacuum lifter degassing.

Bei der Vakuum-Umlaufentgasung tauchen zwei Stutzen eines evakuierten Behälters in die Gießpfanne. In einen der beiden Stutzen wird ein Fördergas geleitet, wodurch eine Umlaufbewegung entsteht und die Metallschmelze durch diesen Stutzen in das Vakuumgefäß steigt, dort zerstäubt und den gewünschten Reaktionen unterworfen wird. Durch den anderen Stutzen kann die entgaste Metallschmelze wieder in die Pfanne zurückgelangen. Nach angemessener Anwendungsdauer ist der gesamte Pfanneninhalt durch das Vakuumgefäß geschleust und entgast.With vacuum circulation degassing, two nozzles of an evacuated are immersed Container into the ladle. In one of the two sockets a conveying gas is passed, causing a circular motion arises and the metal melt through this nozzle into the Vacuum vessel rises, atomizes there and the desired reactions is subjected. Through the other nozzle, the degassed Metal melt back into the pan. To the entire pan content is appropriate for the duration of use passed through the vacuum vessel and degassed.

Beim Vakuum-Heberverfahren wird durch das Heben und Senken des Vakuumgefäßes dessen stutzenförmiges Ende in die Schmelze eingetaucht. Beim Absenken des Vakuumgefäßes steigt ein Teil der Schmelze unter heftiger Bewegung in das Vakuumgefäß. Wird das Vakuumgefäß anschließend angehoben, fließt der Stahl infolge des Eigengewichtes in die Pfanne zurück. Durch wiederholte Anwendung können somit nach und nach Teilmengen in den Entgasungsraum gelangen, so daß nach einer Behandlungsdauer von rund 15 Minuten der Pfanneninhalt mehrfach durchgesetzt und entgast wird.In the vacuum lifting process, lifting and lowering the Vacuum vessel whose nozzle-shaped end is immersed in the melt. When the vacuum vessel is lowered, part of the Melt into the vacuum vessel with vigorous agitation. Will that Then the vacuum vessel is raised, the steel flows as a result weight back into the pan. By repeated Partial amounts can thus be used in the degassing room arrive so that after a treatment period of around For 15 minutes the pan contents were pushed through and degassed several times becomes.

Auf diesem Prinzip beruht auch die aus der DE 36 09 900 C2 bekannte Verfahrenstechnologie bzw. die dort beschriebene Vorrichtung. Bei diesem Verfahren und der Vorrichtung sind zumindest zwei Vakuumkammern vorgesehen, in die geschmolzenes Metall hinaufgepumpt wird, und zwar in eine der Vakuumkammern für eine Entgasung, während das geschmolzene Metall von der anderen Vakuumkammer ausgestoßen wird, um es mit dem geschmolzenen Metall in dem Vorratsbehältnis zu vermischen, wodurch die beiden Vakuumkammern das geschmolzene Metall abwechselnd entgasen. Um die Schmelzflüssigkeit des Metalles aufrechtzuerhalten, werden die Vakuumkammern induktiv beheizt. Mittels dieser Technologie ist jedoch nur eine quasi-kontinuierliche Betriebsweise möglich, bei die Badspiegelschwankungen lediglich dadurch in engen Grenzen gehalten werden können, daß abwechselnd zwei Vakuumkammern die flüssige Metallschmelze ansaugen und ausstoßen. Nachteilig ist nicht nur die Notwendigkeit, zwei Vakuumkammern betreiben zu müssen, sondern auch, daß das behandelte Metall mit dem unbehandelten Metall vermischt wird, da kein Zwangsumlauf gewährleistet ist.This is also the principle based on DE 36 09 900 C2 known process technology or the device described there. In this method and the device are at least Two vacuum chambers are provided in the molten metal is pumped up, in one of the vacuum chambers for one Degassing while the molten metal from the other Vacuum chamber is ejected to make it melted Mixing metal in the storage container, causing the two Vacuum chambers alternately degas the molten metal. In order to maintain the molten metal, the vacuum chambers are heated inductively. Using this technology is, however, only a quasi-continuous mode of operation possible with the bath level fluctuations only in narrow limits can be kept that alternately two Vacuum chambers suck in and expel the molten metal. The disadvantage is not only the need for two vacuum chambers to operate, but also that the treated Metal is mixed with the untreated metal, since none Forced circulation is guaranteed.

Daneben sind auch noch Verfahren bekannt, bei denen die Metallschmelze in einem separaten, nur für die Vakuumbehandlung optimierten Ofengefäß entgast und anschließend vergossen werden. Allerdings ist bei diesen Verfahren neben dem hohen apparativen Aufwand auch zusätzliche Zeit für die Metallschmelzennachbehandlung aufzuwenden, was insgesamt bei kontinuierlichen Stranggießverfahren zu erhöhten Produktionskosten führt. Entsprechendes gilt auch für die sogenannte Gießstrahlentgasung, bei der ein Gießstrahl in eine Vakuumatmosphäre geleitet wird. Schließlich werden auch zur Entgasung Spülgase benutzt, um über einen großen Partialdruckunterschied eine Wasserstoffabscheidung zu erwirken. Allerdings ist der Wirkungsgrad dieser Verfahren recht gering.In addition, processes are also known in which the metal melt in a separate one, optimized only for vacuum treatment Degassing the furnace vessel and then pouring it. However, in addition to the high level of apparatus, these procedures Effort also additional time for the metal melt aftertreatment spend what overall in continuous Continuous casting process leads to increased production costs. The same also applies to so-called pouring jet degassing, in which a pouring jet is directed into a vacuum atmosphere. Finally, purge gases are also used for degassing a large partial pressure difference a hydrogen separation to achieve. However, the efficiency of these processes quite low.

Ein bevorzugten Anwendungsgebiet der vorgestellten Verfahren ist die Herstellung von sauerstofffreiem Kupfer (OF-Kupfer), bei der neben niedrigen Sauerstoffgehalten in der Größenordnung von 1 bis 3 ppm auch niedrige Wasserstoffgehalte von typischerweise unter 1 ppm erreicht werden müssen. Hierbei wird ausgenutzt, daß die Wasserstofflöslichkeit im Kupfer mit fallendem Druck abnimmt und daher der normalerweise im Kupfer gelöste Wasserstoff unter Vakuumbedingungen aus dem Metall entweichen kann, ohne daß der Sauerstoffgehalt wieder zunimmt.A preferred field of application of the methods presented is the production of oxygen-free copper (OF copper), in addition to low oxygen levels in the order of magnitude from 1 to 3 ppm also typically low hydrogen contents must be reached below 1 ppm. This takes advantage of that the hydrogen solubility in copper with falling Pressure decreases and therefore the one normally dissolved in copper Escape hydrogen from the metal under vacuum conditions can without increasing the oxygen content again.

Im Patent Abstracts of Japan zu JP-A-61-056760 wird eine Vorrichtung beschrieben, bei der aus einem Vorratsgefäß geschmolzener Stahl in einen Behälter abgelassen wird, von wo aus dieser flüssige Stahl über eine Transferleitung in einen Gießbehälter überführbar ist. Diese Transferleitung besitzt ein in die genannte erste Kammer mündendes Steigrohr, einen evakuierbaren Raum und ein Fallrohr, über das der flüssige Stahl in den Gießbehälter ablaufen kann. In die Transferleitung kann zusätzlich Argon eingeblasen werden. Die genannte Vorrichtung dient dazu, den Überlauf von Schlacke in das Gießgefäß zu verhindern.In Patent Abstracts of Japan on JP-A-61-056760 there is one Device described in the case of a storage vessel molten steel is drained into a container from where from this liquid steel via a transfer line into a Casting container can be transferred. This transfer line has one riser pipe opening into said first chamber, an evacuable one Space and a downpipe over which the molten steel enters the pouring can can run off. Can in the transfer line additional argon can be injected. The device mentioned serves to prevent slag from overflowing into the pouring vessel.

Es ist Aufgabe der vorliegenden Erfindung, das eingangs genannte Verfahren und die Vorrichtung derart weiterzubilden, daß eine vollkommen kontinuierliche Arbeitsweise ermöglicht wird, daß das entgaste Metall nicht mit unbehandeltem Metall in Berührung kommt, wobei der apparative und verfahrenstechnische Aufwand möglichst gering sein soll. It is an object of the present invention to begin with to further develop the named method and the device, that enables a completely continuous way of working is that the degassed metal is not in untreated metal in Comes into contact, the apparatus and process engineering Effort should be as low as possible.

Apparativ wird die der vorliegenden Erfindung zugrunde liegende Aufgabe durch die Vorrichtung nach Anspruch 1 gelöst. Diese Vorrichtung besitzt einen die zugeführten schmelzflüssigen Metalle aufnehmenden Behälter und eine zur Entgasung dienende Vakuumkammer, wobei in einer einen Zufluß für die schmelzflüssigen Metalle aufweisende erste Kammer ein Steigrohr hineinragt, dessen oberes Ende in die Vakuumkammer mündet, deren Boden eine Abflußöffnung besitzt, die mit einem Fallrohr verbunden ist, dessen unteres, eine Auslaßöffnung bildendes Ende in eine zweite, als Gießkammer ausgebildete Kammer in eine Auslaßdüse mündet und ist dadurch gekennzeichnet, daß das Steigrohr und das Fallrohr mit einer Heizung versehen sind.In terms of apparatus, the one on which the present invention is based Object achieved by the device according to claim 1. This The device has a supplied molten liquid Containers containing metals and one for degassing Vacuum chamber, in which an inflow for the molten First chamber containing metals protrudes a riser pipe, the upper end of which opens into the vacuum chamber, the Bottom has a drain opening connected to a downpipe is its lower end forming an outlet opening into a second chamber, designed as a casting chamber, into an outlet nozzle opens and is characterized in that the riser pipe and the downpipe are provided with a heater.

Weiterbildungen dieser Vorrichtung sind in den Unteransprüchen 2 bis 5 beschrieben.Further developments of this device are in the subclaims 2 to 5 described.

So stehen vorzugsweise die erste und die zweite Kammer räumlich miteinander in Verbindung und weisen einen Damm auf, der die Kammern im unteren Bereich in zwei Badkammern teilt, wobei das Steigrohr und das Fallrohr in unterschiedliche Bereiche unterhalb der oberen Dammkante münden. Wie bereits zuvor beschrieben, kann das in der ersten Kammer vorliegende schmelzflüssige Metall nur über das Steigrohr, die Vakuumkammer und das Fallrohr in den Gießbehälter gelangen, solange die Badspiegel diesseits und jenseits des Dammes unterhalb der oberen Dammkante liegen. Dem ist durch Regelung des Metallschmelzenzuflusses in die erste Kammer sowie durch Abführung der behandelten Metallschmelze aus der Gießkammer Rechnung zu tragen. Bei Ausfall der Vakuumkammer wird der "Damm überflutet", so daß der Gießprozeß auch dann nicht unterbrochen werden muß, wenn keine Entgasung gewünscht wird bzw. wenn die Vakuumkammer ausfällt.The first and the second chamber are preferably spatially located with each other and have a dam that the Divides chambers in the lower area into two bath chambers, the Riser pipe and the down pipe in different areas below the upper edge of the dam. As previously described, can be the molten liquid present in the first chamber Metal only through the riser pipe, the vacuum chamber and the down pipe get into the casting container as long as the bath level on this side and beyond the dam below the upper edge of the dam lie. This is achieved by regulating the flow of molten metal the first chamber and by removing the treated metal melt to take into account from the casting chamber. If the Vacuum chamber, the "dam flooded", so that the casting process does not have to be interrupted even if there is no degassing is desired or if the vacuum chamber fails.

Vorzugsweise sind das Steigrohr und das Fallrohr jeweils parallel zueinander vertikal angeordnet. The riser pipe and the down pipe are preferably each parallel arranged vertically to each other.

Durch entsprechende Regelungen bzw. Steuerungen wird gewährleistet, daß die Badspiegel unterhalb oder oberhalb der oberen Dammkante einstellbar sind. Vorzugsweise wird auch zur Temperaturregelung der Metallschmelze im Einlaufbereich ein Induktor angeordnet, über den eine Aufheizung der Metallschmelze auf gewünschte Temperaturen zur Steuerung der Entgasung während des kontinuierlichen Betriebes gewährleistet werden kann. Um zu verhindern, daß die Gießkammer unerwünschten atmosphärischen Einflüssen ausgesetzt ist, ist diese über ein Wehr, das unterhalb des Badspiegels endet, nach außen hermetisch abgeschlossen.Appropriate regulations or controls ensure that that the bath level below or above the top Dam edge are adjustable. Temperature control is also preferred the metal melt in the inlet area an inductor arranged over which a heating of the molten metal Desired temperatures to control the degassing during the continuous operation can be guaranteed. In order to prevent the gun from unwanted atmospheric When exposed to influences, this is via a weir that is below the bathroom mirror ends, hermetically sealed to the outside.

Die auf das Verfahren bezogene Aufgabe wird durch die Maßnahmen nach Anspruch 6 gelöst, wobei die Metallschmelze aus einer ersten Kammer über ein Steigrohr mit einer unterhalb des Badspiegels liegenden Einlauföffnung in eine als Entgasungsraum dienende Vakuumkammer überführt und von dort schwerkraftbedingt in ein Fallrohr mit einer unteren Auslaßöffnung, die vorzugsweise unterhalb des Badspiegels in der Gießkammer liegt, in die Gießkammer abgeführt wird. Diese Verfahrenstechnik hat den Vorteil, daß die Metallschmelze, welche in die Gießkammer überführt wird, zuvor vollständig beim vorherigen Durchlauf der Vakuumkammer entgast worden ist. Eine Vermischung von bereits entgaster Metallschmelze mit einer unbehandelten Metallschmelze wird somit vermieden. Weiterhin ist auch nur eine Vakuumkammer erforderlich, in die unter alleiniger Nutzung der sich aus den Druckunterschieden zwischen der Vakuumkammer und dem ersten Gefäß ergebenden Hubkraft und unter Ausschluß weiterer Fördermittel die Metallschmelze überführt und von dort aus abgeführt wird. Im Gegensatz zu dem nach dem Stand der Technik beschriebenen Verfahren ist erfindungsgemäß eine kontinuierliche Arbeitsweise möglich. Um die Fließfähigkeit der Metallschmelze insbesondere in der Startphase sicherzustellen, werden das Steigrohr und das Fallrohr beheizt. Insbesondere wird die Heizung mit Brennern durchgeführt. The task related to the procedure is determined by the measures solved according to claim 6, wherein the molten metal from a first chamber via a riser pipe with one below the bath level lying inlet opening in a as a degassing room serving vacuum chamber transferred and from there due to gravity into a downpipe with a lower outlet opening, which is preferably lies below the bath level in the casting chamber, in the casting chamber is discharged. This process technology has the Advantage that the molten metal, which transfers into the casting chamber is previously complete during the previous run of the Vacuum chamber has been degassed. A mix of already degassed molten metal with an untreated molten metal is thus avoided. Furthermore there is only one vacuum chamber required in the sole use of which results from the Differences in pressure between the vacuum chamber and the first Vessel lifting capacity and excluding other funding the molten metal is transferred and removed from there becomes. In contrast to that according to the prior art described method is a continuous according to the invention Working method possible. To the flowability of the To ensure molten metal, especially in the start-up phase, the riser pipe and the down pipe are heated. In particular the heating is carried out with burners.

Weiterbildungen dieses Verfahrens sind in den Unteransprüchen beschrieben.Further developments of this method are in the subclaims described.

So werden durch Regelung der Metallschmelzenzufuhr in die erste Kammer und des Ablassens der Metallschmelze aus der Gießkammer die Badspiegel in der ersten Kammer und der Gießkammer in unterschiedlichen Höhenniveaus eingestellt. Durch das Steigrohr und das Fallrohr ist zwischen den beiden Kammern eine Verbindung geschaffen, die nach Art der kommunizierenden Röhren arbeitet, wobei entsprechend der Höhendifferenz zwischen dem höheren Badspiegel in der ersten Kammer und dem Badspiegel in der Gießkammer ein Metallschmelzenfluß aufrechterhalten wird. Aus der Gießkammer kann die Metallschmelze kontinuierlich oder diskontinuierlich abgelassen werden.So by regulating the molten metal supply in the first Chamber and the discharge of the molten metal from the casting chamber the bath level in the first chamber and the casting chamber in different height levels. Through the riser pipe and the downpipe is a connection between the two chambers created according to the type of communicating tubes works, according to the height difference between the higher bath level in the first chamber and the bath level in a metal melt flow is maintained in the casting chamber. The molten metal can continuously or from the casting chamber be drained discontinuously.

Nach einer weiteren bevorzugten Ausführungsform sind die erste und die zweite Kammer räumlich miteinander verbunden und im unteren Bereich durch einen Damm in zwei Badkammern geteilt. Liegen die Badspiegel in der ersten und der zweiten Kammer unterhalb der oberen Kante des Dammes, wird die Metallschmelze aus der ersten Kammer über das Steigrohr in die Vakuumkammer und von dort über das Fallrohr in die Gießkammer geführt. Bei Ausfall der Vakuumkammer, z.B. bei einem Pumpendefekt, oder auch in Fällen, in denen keine Entgasung gewünscht wird, wird der Badspiegel so eingestellt, daß dieser oberhalb der Kante des genannten Dammes liegt, so daß sich in der ersten und der zweiten Kammer ein gemeinsamer durchgehender Badspiegel bildet und daß schmelzflüssige Metall unter Umgehung der Vakuumkammer unmittelbar in die Gießkammer gelangt.According to a further preferred embodiment, the first and the second chamber spatially connected and in lower area divided into two bath chambers by a dam. The bathroom mirrors are located in the first and second chamber below the top edge of the dam, the metal melt from the first chamber via the riser pipe into the vacuum chamber and from there through the downpipe into the casting chamber. at Failure of the vacuum chamber, e.g. in the event of a pump defect, or even in cases where degassing is not required the bathroom mirror is set so that it is above the edge of the said dam lies, so that in the first and the second chamber forms a common continuous bathroom mirror and that molten metal bypassing the vacuum chamber directly into the casting chamber.

Die Entgasungskinetik ist sehr stark von der Temperatur abhängig, weshalb nach einer weiteren Ausgestaltung der Erfindung die Metallschmelze induktiv beheizt wird, womit es möglich ist, die Entgasung zu steuern. The degassing rate is very dependent on the temperature, which is why according to a further embodiment of the invention the molten metal is heated inductively, which makes it possible to control the degassing.

Nach einer weiteren Ausgestaltung der Erfindung wird die Aufenthaltsdauer der Metallschmelze in der Vakuumkammer über den Druck in dieser Vakuumkammer geregelt.According to a further embodiment of the invention, the length of stay the molten metal in the vacuum chamber over the Pressure regulated in this vacuum chamber.

Die vorliegende Erfindung wird im folgenden anhand eines konkreten Ausführungsbeispieles näher anhand der Abbildungen erläutert. Es zeigen

Fig. 1 und 2
jeweils Querschnitte durch eine erfindungsgemäße Vorrichtung.
The present invention is explained in more detail below on the basis of a specific exemplary embodiment with reference to the figures. Show it
1 and 2
each cross sections through a device according to the invention.

Die dargestellte Anlage besitzt eine Eingießkammer 10, in die das flüssige Metall kontinuierlich aus einem vorgelagerten Speicherofen eingefüllt wird. Aus dieser Eingießkammer 10 läuft das schmelzflüssige Metall durch einen Induktorkanal bzw. Induktorkanäle 11 in die erste Kammer 20, in die ein vertikal angeordnetes Steigrohr 15 hineinragt, so daß das Steigrohr mit seiner unteren Öffnung unterhalb des Badspiegels liegt. Das Steigrohr 15 sowie das Fallrohr 16, das in eine Gießkammer 13 hineinragt und dessen untere Öffnung ebenfalls unter dem dortigen Badspiegel liegt, sind in Form von Stutzen des Bodens der Vakuumkammer 17 ausgebildet, die über einen Stutzen 18 mittels einer Pumpe evakuierbar ist. Die Gießkammer 13 sowie die erste Kammer 20 werden durch einen Damm 12 voneinander getrennt. Solange der Badspiegel in der Eingießkammer 10 bzw. der ersten Kammer 20 zwischen den Grenzen 21 und 22 eingestellt ist, kann das schmelzflüssige Metall entsprechend der Darstellung in Fig. 1 von der ersten Kammer 20 nur über das Steigrohr, die Vakuumkammer 17 und das Fallrohr in die Gießkammer 13 gelangen. Wird die Maximallinie 21 für das Badniveau in der ersten Kammer 20 überschritten, fließt das schmelzflüssige Metall, wie in Fig. 2 dargestellt, unmittelbar in die Gießkammer 13, was in dem Falle genutzt werden kann, wenn das flüssige Metall nicht entgast werden soll oder die Vakuumkammer 17 aus anderen Gründen ausfällt. Im Einlaufbereich befindet sich weiterhin ein Induktor, mittels dessen die fließende Metallschmelze aufgeheizt werden kann. Mit diesem Induktor ist ein ideales Mittel zur Steuerung der Entgasung möglich, die stark temperaturabhängig ist.The system shown has a pouring chamber 10 into which the liquid metal continuously from an upstream Storage oven is filled. Runs out of this pouring chamber 10 the molten metal through an inductor channel or Inductor channels 11 in the first chamber 20, in which a vertical arranged riser 15 protrudes so that the riser with its lower opening is below the bathroom mirror. The Riser pipe 15 and the down pipe 16, which in a casting chamber 13th protrudes and its lower opening also under the one there Bathroom mirrors are in the form of connecting pieces of the floor Vacuum chamber 17 formed by means of a nozzle 18 a pump can be evacuated. The casting chamber 13 and the first Chamber 20 are separated from one another by a dam 12. As long as the bath level in the pouring chamber 10 or the first Chamber 20 can be set between the limits 21 and 22 the molten metal as shown in Fig. 1 of the first chamber 20 only via the riser pipe Vacuum chamber 17 and the downpipe get into the casting chamber 13. The maximum line becomes 21 for the bathroom level in the first Exceeding chamber 20, the molten metal flows like shown in Fig. 2, directly into the casting chamber 13, which in the case can be used if the liquid metal is not should be degassed or the vacuum chamber 17 for other reasons fails. In the entry area there is still a Inductor, by means of which the flowing molten metal is heated can be. With this inductor is an ideal means to control the degassing, which is strongly temperature-dependent is.

Zur thermischen Stabilisierung während der Anlaufphase sind Brenner 19 vorgesehen, welche das Steigrohr 15 und das Fallrohr 16 heizen. Gegenüber einer induktiven Beheizung hat diese Brennerbeheizung den Vorteil, daß sie eine Vorwärmung der gesamten Kammer einschließlich der Steigrohre erlaubt. Die Gießkammer 13 besitzt ferner eine Düse 14, worüber das schmelzflüssige Metall abgelassen werden kann. Um das entgaste Metall vor einem Luftzutritt zu schützen, ist die Gießkammer 13 über ein Wehr 24 von der übrigen Ofenatmosphäre getrennt, so daß die Gießkammer nach außen hermetisch abgeschlossen ist. Das Wehr endet mit seiner unteren Kante unterhalb des Badspiegels in der Gießkammer.For thermal stabilization during the start-up phase Burner 19 provided which the riser pipe 15 and the down pipe 16 heat. Compared to inductive heating, this has Burner heating has the advantage that it preheats the Entire chamber including the risers allowed. The Casting chamber 13 also has a nozzle 14, through which the molten Metal can be drained. The degassed metal To protect against air ingress, the casting chamber 13 is over a weir 24 separated from the rest of the furnace atmosphere, so that the Casting chamber is hermetically sealed to the outside. The weir ends with its lower edge below the bathroom mirror in the Casting chamber.

Die erfindungsgemäße Vorrichtung arbeitet folgendermaßen:The device according to the invention works as follows:

Über einen Zulauf wird die Eingießkammer 10 mit schmelzflüssigem Metall kontinuierlich gefüllt, wobei der Badspiegel zwischen den Grenzlinien 21 und 22 liegt. Gleichzeitig wird in der Vakuumkammer 17 ein Unterdruck eingestellt, der bewirkt, daß das schmelzflüssige Metall über das Steigrohr 15 aufsteigt, in der Vakuumkammer 17 entgast wird. Das schmelzflüssige Metall fließt über das Fallrohr 16 jenseits des Dammes 12 in die Gießkammer 13, solange der dortige Badspiegel unterhalb dem Niveau des Badspiegels der Eingießkammer liegt. Während des Entgasens werden die Brenner 19 betrieben, die für eine hinreichende Temperaturführung sorgen. Das Niveau des Badspiegels 27 in dem Behälter 22 entspricht jeweils dem statischen Druck in der Vakuumkammer 17.The pouring chamber 10 is filled with molten material via an inlet Metal continuously filled, with the bathroom mirror between the boundary lines 21 and 22. At the same time, in the Vacuum chamber 17 set a negative pressure, which causes the molten metal rises over the riser pipe 15, in the vacuum chamber 17 is degassed. The molten metal flows through the downpipe 16 beyond the dam 12 into the casting chamber 13 as long as the bath level there is below the level the bath level of the pouring chamber. During degassing the burners 19 are operated for adequate temperature control to care. The level of the bath level 27 in the Container 22 corresponds to the static pressure in the Vacuum chamber 17.

Nach Beendigung der Vakuumbehandlung oder in den Fällen, in denen keine Vakuumbehandlung benötigt oder gewünscht wird, wird der Badspiegel in der ersten Kammer 20 so eingestellt, daß der Damm 12 überflutet wird, so daß das schmelzflüssige Metall unmittelbar in die Gießkammer 13 gelangen kann.After completion of the vacuum treatment or in cases in where no vacuum treatment is required or desired the bath level in the first chamber 20 is adjusted so that the Dam 12 is flooded so that the molten metal can get directly into the casting chamber 13.

Claims (10)

  1. Device for the degassing of molten metals, preferably molten copper and subsequent casting of the degassed metal with a vessel (10, 20) receiving a supplied molten metal and a vacuum chamber serving for degassing, whereby an ascension pipe (15) extends into a first chamber (20) having an inlet opening for the molten metals, the upper end of the ascension pipe ending in the vacuum chamber (17), the bottom of which has an outlet opening which is connected with a down pipe (16) whose lower outlet forming end opens into a second chamber formed as a casting chamber (13) with an outlet nozzle (14),
    characterized in that
    the ascension pipe (15) and the down pipe (16) are provided with a heating device (19).
  2. Device according to claim 1, characterised in that the first chamber (20) and the casting chamber (13) are spatially connected with one another and have a dam (12) which subdivides the chambers (20, 13) in the lower region into two bath chambers, whereby the ascension pipe (15) and the down pipe (16) open into different regions below the upper dam edge and/or are parallel to one another and each vertically arranged.
  3. Device according to one of the claims 1 or 2, characterised in that the heating device for the ascension pipe (15) and the down pipe (16) is comprised of at least one burner (19).
  4. Device according to one of claims 1 to 2, characterised in that the casting chamber (13) is hermetically sealed to the exterior via a weir (24) which ends below the bath level.
  5. Device according to one of claims 1 to 4, characterised in that an inductor (23) is provided for temperature control of the metal bath in an inlet region (10, 11, 20)
  6. Method for the continuous degassing of molten metals, preferably molten copper and subsequent casting of the degassed metal, whereby for degassing the molten metal is guided from a first chamber (20) via an ascension pipe (15) with an inlet opening lying below the bath level into a vacuum chamber (17) serving as a degassing compartment solely by the use of lifting force caused by the pressure difference between the vacuum chamber (17) and the first chamber (20) and without any further conveying means and from there by gravity in a down pipe (16) with a lower outlet opening below the bath level in the casting chamber (13), characterised in that the ascension pipe (15) and the down pipe (16) are heated.
  7. Method according to claim 6, characterised in that by control of the metal melt feed chamber (21) and the discharge of the molten melt from the casting chamber (13) different height levels of the bath are adjusted, whereby in that the bath level is so adjusted that it either lies for degassing of the metals below the edge of a dam (12) separating the spaces of the first chamber (20) and the casting chamber (13) which are connected one to the other for the rest into two separate bath chambers, of which the ascension pipe (15) extends into the first bath chamber and the down pipe (16) extends into the second bath chamber or that the bath level lies above the edge of the dam (12) and forms a common throughgoing bath level in the first chamber (20) and in the casting chamber (13) when the casting process is to proceed by avoiding the degassing.
  8. Method according to one of claims 6 or 7, characterised in that the ascension pipe (15) and the down pipe (16) are heated especially in the starting phase, preferably by burners (19)
  9. Method according to one of claims 6 to 8, characterised in that the resistance times of the metal melt in the vacuum chamber (17) is controlled by the pressure in this vacuum chamber (17).
  10. Method according to one of claims 6 to 9, characterised in that the metal melt temperature is controlled by means of inductive heating for the purpose of controlling the degassing.
EP99944261A 1998-07-15 1999-07-01 Method and device for the continuous degassing of molten metals Expired - Lifetime EP1105234B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19831675 1998-07-15
DE19831675 1998-07-15
PCT/DE1999/002028 WO2000003821A1 (en) 1998-07-15 1999-07-01 Method and device for the continuous degassing of molten metals

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EP1105234A1 EP1105234A1 (en) 2001-06-13
EP1105234B1 true EP1105234B1 (en) 2002-05-29

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EP (1) EP1105234B1 (en)
JP (1) JP2002520162A (en)
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CN101279360B (en) * 2008-05-15 2010-09-29 天津钢管集团股份有限公司 Method for producing low alloyed steel continuous casting circular tube blank with a diameter of 350-400mm
CN106480257B (en) * 2015-08-29 2018-05-22 党祎贤 Pump valve vacuum degassing device
CN108480575A (en) * 2018-04-10 2018-09-04 佛山市三水万瑞达环保科技有限公司 A kind of melt depassing unit

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AT515235A1 (en) * 2013-12-30 2015-07-15 Inteco Special Melting Technologies Gmbh Method and arrangement for vacuum block casting

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WO2000003821A1 (en) 2000-01-27
JP2002520162A (en) 2002-07-09
EP1105234A1 (en) 2001-06-13
DE59901564D1 (en) 2002-07-04
US6454829B1 (en) 2002-09-24

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