EP1044285A1 - Operation method of furnace equipment for magnesium alloys - Google Patents

Operation method of furnace equipment for magnesium alloys

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Publication number
EP1044285A1
EP1044285A1 EP98955253A EP98955253A EP1044285A1 EP 1044285 A1 EP1044285 A1 EP 1044285A1 EP 98955253 A EP98955253 A EP 98955253A EP 98955253 A EP98955253 A EP 98955253A EP 1044285 A1 EP1044285 A1 EP 1044285A1
Authority
EP
European Patent Office
Prior art keywords
nitrogen
gas
inert gas
air
conditioned room
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
Application number
EP98955253A
Other languages
German (de)
French (fr)
Other versions
EP1044285B1 (en
Inventor
Helmut Schwaiger
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.)
TCG Unitech AG
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TCG Unitech AG
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Publication date
Application filed by TCG Unitech AG filed Critical TCG Unitech AG
Publication of EP1044285A1 publication Critical patent/EP1044285A1/en
Application granted granted Critical
Publication of EP1044285B1 publication Critical patent/EP1044285B1/en
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Classifications

    • 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
    • C22B9/006—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals with use of an inert protective material including the use of an inert gas
    • 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
    • C22B26/00—Obtaining alkali, alkaline earth metals or magnesium
    • C22B26/20—Obtaining alkaline earth metals or magnesium
    • C22B26/22—Obtaining magnesium
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
    • F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
    • F27B3/22—Arrangements of air or gas supply devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D7/00—Forming, maintaining, or circulating atmospheres in heating chambers
    • F27D7/06—Forming or maintaining special atmospheres or vacuum within heating chambers

Definitions

  • the present invention relates to a method for operating furnace systems for magnesium alloys, in which a bathroom surface is covered with a protective gas which contains a sulfur compound.
  • SF 6 is used as such a protective gas, which reacts with the magnesium of the melt and forms a protective layer which protects the melt from the ingress of atmospheric oxygen. Mixtures of SF r and nitrogen are sometimes used for this purpose. Since SF 6 is a greenhouse gas, its use is environmentally unsafe. In addition, the cost of this gas is relatively high.
  • S0 2 As protective gas.
  • S0 2 is available relatively inexpensively and, like SF (), forms a protective layer on a magnesium melt.
  • S0 2 has hitherto been prevented by the fact that it is an extremely unpleasant smelling gas which is harmful to health and corrosive to corrosion in medium to high concentrations.
  • S0 2 in a conventional manner, an escape of gas from the furnaces or the like cannot be avoided, which leads to an impermissible pollution of the environment. In particular, the MAK values are exceeded by far.
  • the object of the present invention is to provide a method which, on the one hand, enables safe treatment of magnesium melts, but on the other hand causes the least possible environmental pollution.
  • this object is achieved in that a mixture of SO 2 and an inert gas is used as the protective gas, the volume fraction of SO 2 being set precisely to a value which is preferably in a range between 0.3% and 1.5% between 0.5% and 1.0%.
  • the volume fraction of SO 2 being set precisely to a value which is preferably in a range between 0.3% and 1.5% between 0.5% and 1.0%.
  • Nitrogen is particularly preferably used as the inert gas. Nitrogen is available at low cost and is not environmentally critical. In a particularly advantageous embodiment of the method according to the invention it is provided that the mixing of SO 2 and the inert gas takes place in an air-conditioned room, the temperature of which is kept above 22 ° C. and preferably in a range between 25 ° C. and 35 ° C. It has been found that a satisfactory mixture of S0 2 and nitrogen is only possible at a certain minimum temperature at a power pressure> 2 bar. In addition, the mixture in an air-conditioned room can reliably avoid temperature-related volume and pressure fluctuations in the gases involved. A temperature of about 30 ° C. is particularly preferred.
  • the present invention relates to a device for producing a protective gas for furnace plants for Magncsiumlcgicrungen with a pre-container for a sulfur compound, a storage container for an inert gas and a mixing device.
  • the device according to the invention is characterized in that the mixing device is designed for precise flow control of SO and nitrogen, and is arranged in an air-conditioned room.
  • Safety gas cylinders are installed in an air-conditioned room to hold SO 2 bottles. Nitrogen is taken from a normal tank.
  • the mixing of S0 2 and nitrogen takes place via electronic mass flow meters, which are arranged in the air-conditioned room.
  • the gas mixture produced in this way is transported to the corresponding furnace systems via pipes and adapted to consumption via local control systems. These can be melting furnaces. Trade warm shark ovens, dosing ovens and ingot casting belts for magnesium solutions.
  • S0 2 sensors are installed in the safety gas cylinders, which already respond to low S0 2 concentrations. After an S0 2 bottle has been emptied, it is flushed with the corresponding pipelines with nitrogen in order to rule out a health hazard during bottle washing. In this way it can be reliably prevented that SO 2 gets into the environment.
  • FIG. 1 The basic circuit diagram of a device according to the invention is shown in FIG.
  • the broken lines 1 describe the components which are arranged in two security cabinets.
  • Gas bottles 2 serve as storage containers for sulfur dioxide, which are supplied to a manifold 4 via shut-off valves 3.
  • a control line 5a, which controls a solenoid valve 6, is supplied via a manometer 5.
  • a supply line 8 for S0 2 is connected via a further shut-off valve 7.
  • a storage container 9 for nitrogen is connected via a line 10, a shut-off valve 11 and a check valve 12 to the distribution line 4 in each of the two safety cupboards 1 in order to provide nitrogen for flushing the lines when the bottles 2 are changed.
  • a manometer 13 indicates the nitrogen pressure in a main nitrogen line 16.
  • the individual bottles 2 are connected to an exhaust gas collection line 19 via shut-off valves 17 and exhaust gas lines 18.
  • the distribution line 4 is vented into the exhaust manifold 19 via its own shut-off valves 20.
  • the mixing device for supplying the individual consumers is shown in the right section of the figure. Since the individual mixers 21 are basically constructed in the same way, only one is designated with a reference number and is explained in the description.
  • the individual mixers 21 are supplied with nitrogen via a first vertical bar 22 and with sulfur dioxide via a second vertical bar 23.
  • a third vertical bar 24 is used to connect the mixers 21 to the exhaust manifold line 19.
  • Shut-off valves 25 and 26 are provided in the individual mixers 21, which are connected to the vertical bar 22 and 23, respectively.
  • Pressure gauges 27 and 28 indicate the nitrogen and sulfur dioxide pressure after the shut-off valves 25 and 26, respectively.
  • a shutoff valve 29 for purging is provided between the nitrogen line and the sulfur dioxide line, which is followed by a check valve 30.
  • Highly precise mass flow rate measurements 31 for nitrogen and 32 for sulfur dioxide serve to set a precise ratio of the two gases.
  • Filters 33 and 34 are connected upstream of the flow measurements 31 and 32.
  • shut-off valves 35 and 36 and a check valve 37 in the nitrogen line the gases are brought together into a supply line 38, which is provided with a pressure gauge 39 and a shut-off valve 40.
  • a flushing line 41 with a shut-off valve 42 serves to avoid environmental pollution during maintenance work or the like.
  • the entire arrangement, which is shown in the figure, is arranged according to the invention in an air-conditioned room, which is kept at a temperature of about 30 ° C. In this way, the mixing ratio of the gases can be kept at a precisely predetermined value and good mixing can be ensured.
  • Mcngcnrcgler not shown, can be provided for the individual consumers, but these only influence the quantity of the gas mixture supplied and not the composition of the gas.
  • the present invention thus not only enables cost savings, but also a significant reduction in environmental pollution and particularly safe operation when handling magnesium melts.

Abstract

The present invention relates to an operation method of furnace equipment for magnesium alloys, wherein a bath surface is covered with a protection gas containing a sulphur compound. The purpose of this invention is to reduce the production costs and the damage to the environment as well as to ensure a particularly safe operation when handling magnesium liquid baths. To this end, the protection gas consists in a mixture of SO2 with an inert gas, wherein the proportion by volumes of SO2 is set at a precise value in a range of between 0.3 % and 1.5 %, preferably of between 0.5 % and 1.0 %.

Description

Verfahren zum Betrieb von Ofenanlagcn für MagnesiumlegierungenProcess for operating furnace systems for magnesium alloys
Die vorliegende Erfindung betrifft ein Verfahren zum Betrieb von Ofenanlagcn für Magnesi- umlegicrungen, bei dem eine Badobcrtläche mit einem Schutzgas abgedeckt wird, das eine Schwefclverbindung enthält.The present invention relates to a method for operating furnace systems for magnesium alloys, in which a bathroom surface is covered with a protective gas which contains a sulfur compound.
Bei Anlagen, in denen ilüssigcs Magnesium vorliegt, müssen besondere Vorkehrungen getroffen werden, um den Hinzutritt von Luftsauerstoff zuverlässig zu verhindern, da Magnesium in flüssigem Zustand extrem brennbar ist. Als ein solches Schutzgas wird beispielsweise SF6 verwendet, das mit dem Magnesium der Schmelze reagiert und eine Schutzschicht ausbildet, die die Schmelze vor dem Hinzutritt von Luftsauerstoff schützt. Fallweise werden für diesen Zweck auch Gemische aus SFr, und Stickstoff eingesetzt. Da es sich bei SF6 um ein Treibhausgas handelt, ist die Verwendung aus Umwcltschutzgründcn bedenklich. Außerdem sind die Kosten für dieses Gas relativ hoch.In plants in which ilüssigcs magnesium is present, special precautions must be taken to reliably prevent the entry of atmospheric oxygen, since magnesium is extremely flammable in the liquid state. SF 6 , for example, is used as such a protective gas, which reacts with the magnesium of the melt and forms a protective layer which protects the melt from the ingress of atmospheric oxygen. Mixtures of SF r and nitrogen are sometimes used for this purpose. Since SF 6 is a greenhouse gas, its use is environmentally unsafe. In addition, the cost of this gas is relatively high.
Alternativ dazu ist bereits überlegt worden, als Schutzgas S02 einzusetzen. S02 ist relativ kostengünstig verfugbar und bildet ebenso wie SF() eine Schutzschicht auf einer Magnesium- schmclze. Der Einsatz von S02 wurde jedoch bisher dadurch verhindert, daß es sich dabei um ein extrem unangenehm riechendes Gas handelt, das in mittleren bis höheren Konzentrationen gesundheitsschädlich und korrosionstordcmd ist. Beim Einsatz von S02 in herkömmlicher Weise ist ein Austritt von Gas aus den Öfen oder dergleichen nicht zu vermeiden, der zu einer unzulässigen Belastung der Umgebung fuhrt. Insbesondere werden dabei die MAK-Werte bei weitem überschritten.Alternatively, it has already been considered to use S0 2 as protective gas. S0 2 is available relatively inexpensively and, like SF (), forms a protective layer on a magnesium melt. However, the use of S0 2 has hitherto been prevented by the fact that it is an extremely unpleasant smelling gas which is harmful to health and corrosive to corrosion in medium to high concentrations. When using S0 2 in a conventional manner, an escape of gas from the furnaces or the like cannot be avoided, which leads to an impermissible pollution of the environment. In particular, the MAK values are exceeded by far.
Weiters ist es bekannt, Gasgemische aus S02 und getrockneter Luft als Schutzgas für Magnesiumöfen einzusetzen. Dabei ist es jedoch nicht gelungen, einerseits die toxische und korrosive Wirkung von S02 zu kontrollieren und andererseits einen sicheren Ofenbetrieb zu realisieren.Furthermore, it is known to use gas mixtures of S0 2 and dried air as a protective gas for magnesium furnaces. However, it was not possible to control the toxic and corrosive effects of S0 2 on the one hand and to implement safe furnace operation on the other.
Aufgabe der vorliegenden Erfindung ist es, ein Verfahren zu schaffen, das einerseits eine sichere Behandlung von Magnesiumschmelzcn ermöglicht, das jedoch andererseits eine möglichst geringe Umweltbelastung hervorruft.The object of the present invention is to provide a method which, on the one hand, enables safe treatment of magnesium melts, but on the other hand causes the least possible environmental pollution.
Erfindungsgemäß wird diese Aufgabe dadurch gelöst, daß als Schutzgas ein Gemisch von S02 und einem Inertgas verwendet wird, wobei der Volumsanteil von SO2 genau auf einen Wert eingestellt wird, der in einem Bereich zwischen 0,3 % und 1 ,5 %, vorzugsweise zwischen 0,5 % und 1,0 %, liegt. In überraschender Weise hat sich herausgestellt, daß es im Fall von S02 einen kleinen Bereich gibt, in dem einerseits eine ausreichende Schutzwirkung vorhanden ist, jedoch andererseits eine Umweltbelastung weitgehend vermieden werden kann. Wesentlich an der vorliegenden Erfindung ist die Einstellung eines genauen Wertes der S02-Konzen- tration im Schutzgas. Da mit sehr geringen SO:-Konzentrationcn gearbeitet wird, ist eine exakte Prozeßtührung und das Veπneidcn von Schwankungen in der Gaszusammensetzung sehr wichtig, um Brände zu vermeiden.According to the invention, this object is achieved in that a mixture of SO 2 and an inert gas is used as the protective gas, the volume fraction of SO 2 being set precisely to a value which is preferably in a range between 0.3% and 1.5% between 0.5% and 1.0%. Surprisingly, it has been found that in the case of S0 2 there is a small area in which, on the one hand, there is a sufficient protective effect is, on the other hand, environmental pollution can be largely avoided. What is essential to the present invention is the setting of an exact value of the SO 2 concentration in the protective gas. Since very low SO : concentrations are used, exact process control and the variation of gas composition fluctuations are very important in order to avoid fires.
Besonders bevorzugt wird als Inertgas Stickstoff eingesetzt. Stickstoff ist kostengünstig verfügbar und nicht umweltkritisch. In einer besonders begünstigten Ausführungsvariantc des erfindungsgemäßen Verfahrens ist vorgesehen, daß die Mischung von S02 und dem Inertgas in einem klimatisiertem Raum erfolgt, dessen Temperatur oberhalb von 22°C und vorzugsweise in einem Bereich zwischen 25°C und 35°C gehalten wird. Es hat sich herausgestellt, daß bei einem Leistungsdruck > 2 bar eine zufriedenstellende Mischung von S02 und Stickstoff nur ab einer gewissen Mindesttemperatur möglich ist. Außerdem können durch die Mischung in einem klimatisierten Raum temperaturbedingte Volums- und Druckschwankun- gen der beteiligten Gase sicher vennieden werden. Besonders bevorzugt ist eine Temperatur von etwa 30°C.Nitrogen is particularly preferably used as the inert gas. Nitrogen is available at low cost and is not environmentally critical. In a particularly advantageous embodiment of the method according to the invention it is provided that the mixing of SO 2 and the inert gas takes place in an air-conditioned room, the temperature of which is kept above 22 ° C. and preferably in a range between 25 ° C. and 35 ° C. It has been found that a satisfactory mixture of S0 2 and nitrogen is only possible at a certain minimum temperature at a power pressure> 2 bar. In addition, the mixture in an air-conditioned room can reliably avoid temperature-related volume and pressure fluctuations in the gases involved. A temperature of about 30 ° C. is particularly preferred.
Wcitcrs betrifft die vorliegende Erfindung eine Vorrichtung zur Erzeugung eines Schutzgases für Ofenanlagcn iür Magncsiumlcgicrungen mit einem Vo itsbchälter für eine Schwefelvcr- bindung, einem Vorratsbehälter für ein Inertgas und einer Mischeinrichtung. Die erfindungs- gemäßc Vorrichtung ist dadurch gekennzeichnet, daß die Mischeinrichtung zur genauen Durchflußrcgelung von SO, und Stickstoff ausgebildet ist, und in einem klimatisierten Raum angeordnet ist. In einem klimatisierten Raum sind Sichcrhcitsgaszcllcn angebracht, die SO2- Flaschen aufnehmen. Stickstoff wird aus einem üblichen Tank entnommen. Die Mischung von S02 und Stickstoff erfolgt über elektronische Massendurchflußmesser, die in dem klimatisierten Raum angeordnet sind. Das so hergestellte Gasgemisch wird zu den entsprechenden Ofenanlagen über Rohrleitungen transportiert und über örtliche Regelsystemc dem Verbrauch angepaßt. Dabei kann es sich um Schmelzöfen. Warmhai teöfen, Dosieröfen und Masselgießbänder für Magnesiumlcgicrungen handeln.The present invention relates to a device for producing a protective gas for furnace plants for Magncsiumlcgicrungen with a pre-container for a sulfur compound, a storage container for an inert gas and a mixing device. The device according to the invention is characterized in that the mixing device is designed for precise flow control of SO and nitrogen, and is arranged in an air-conditioned room. Safety gas cylinders are installed in an air-conditioned room to hold SO 2 bottles. Nitrogen is taken from a normal tank. The mixing of S0 2 and nitrogen takes place via electronic mass flow meters, which are arranged in the air-conditioned room. The gas mixture produced in this way is transported to the corresponding furnace systems via pipes and adapted to consumption via local control systems. These can be melting furnaces. Trade warm shark ovens, dosing ovens and ingot casting belts for magnesium solutions.
In den Sicherhcitsgaszcllen sind S02-Sensorcn angebracht, die bereits auf geringe S02-Kon- zentrationen ansprechen. Nachdem eine S02-Flasehc geleert worden ist, wird diese samt den entsprechenden Rohrleitungen mit Stickstoff gespült, um eine Gesundheitsgefahr beim Flaschcnwcchscl auszuschließen. Auf diese Weise kann zuverlässig verhindert werden, daß SO2 in die Umgebung gelangt.S0 2 sensors are installed in the safety gas cylinders, which already respond to low S0 2 concentrations. After an S0 2 bottle has been emptied, it is flushed with the corresponding pipelines with nitrogen in order to rule out a health hazard during bottle washing. In this way it can be reliably prevented that SO 2 gets into the environment.
Durch die geringe S02-Konzentration des Schutzgases kann eine Umweltbelastung und insbesondere eine Geruchsbelästigung auch im Ofcnbcrcich sicher vennieden werden, wobei durch das genau eingestellte Mischungsverhältnis ein sicherer Betrieb gewährleistet werden kann.Due to the low S0 2 concentration of the protective gas, environmental pollution and in particular an unpleasant smell can also be reliably avoided in the oven, whereby safe operation can be guaranteed by the precisely set mixing ratio.
In der Fig. ist das grundsätzliche Schaltungsdiagramm einer erfindungsgemäßen Vorrichtung dargestellt. Mit den unterbrochenen Linien 1 sind die Bauteile umschrieben, die in zwei Sicherhcits- schränken angeordnet sind. Gasflaschen 2 dienen als Vorratsbehältcr lür Schwcfcldioxyd, das über Absperrventile 3 einer Sammelleitung 4 zugeführt wird. Über ein Manometer 5 wird eine Steuerlcitung 5a versorgt, die ein Magnetventil 6 ansteuert. Über ein weiteres Absperrventil 7 ist eine Versorgungsleitung 8 für S02 angeschlossen.The basic circuit diagram of a device according to the invention is shown in FIG. The broken lines 1 describe the components which are arranged in two security cabinets. Gas bottles 2 serve as storage containers for sulfur dioxide, which are supplied to a manifold 4 via shut-off valves 3. A control line 5a, which controls a solenoid valve 6, is supplied via a manometer 5. A supply line 8 for S0 2 is connected via a further shut-off valve 7.
Ein Vorratsbehältcr 9 für Stickstoff ist über je eine Leitung 10, ein Absperrventil 1 1 und ein Rückschlagventil 12 mit der Verteilerleitung 4 in jedem der beiden Sicherhcitsschränkc 1 verbunden, um Stickstoff zur Spülung der Leitungen beim Wechseln der Flaschen 2 zur Verfügung zu stellen. Ein Manometer 13 zeigt den Stickstoff-Druck in einer Stickstoff-Hauptleitung 16 an. Über Absperrventile 17 und Abgaslcitungen 18 stehen die einzelnen Flaschen 2 mit einer Abgassammellcitung 19 in Verbindung. Die Verteilerleitung 4 wird über eigene Absperrventile 20 in die Abgassammellcitung 19 entlüftet. Durch die oben beschriebene Schaltung ist es möglich, vor dem Wechseln einer der Flaschen 2 die entsprechenden Lei- tungsabschnittc mit Stickstoff zu spülen, so daß ein Austreten von S02 sicher vennieden werden kann.A storage container 9 for nitrogen is connected via a line 10, a shut-off valve 11 and a check valve 12 to the distribution line 4 in each of the two safety cupboards 1 in order to provide nitrogen for flushing the lines when the bottles 2 are changed. A manometer 13 indicates the nitrogen pressure in a main nitrogen line 16. The individual bottles 2 are connected to an exhaust gas collection line 19 via shut-off valves 17 and exhaust gas lines 18. The distribution line 4 is vented into the exhaust manifold 19 via its own shut-off valves 20. The circuit described above makes it possible to purge the corresponding line sections c with nitrogen before changing one of the bottles 2, so that leakage of SO 2 can be reliably avoided.
In dem rechten Abschnitt der Fig. ist die Mischeinrichtung zur Versorgung der einzelnen Verbraucher dargestellt. Da die einzelnen Mischer 21 grundsätzlich gleich aufgebaut sind, ist nur einer mit Bczugszcichcn bezeichnet und in der Beschreibung erklärt.The mixing device for supplying the individual consumers is shown in the right section of the figure. Since the individual mixers 21 are basically constructed in the same way, only one is designated with a reference number and is explained in the description.
Die einzelnen Mischer 21 werden über eine erste Vertcilcrleiste 22 mit Stickstoff und über eine zweite Vertcilcrleiste 23 mit Schwcfeldioxyd versorgt. Eine dritte Vertcilcrleiste 24 dient zur Verbindung der Mischer 21 mit der Abgassammellcitung 19. In den einzelnen Mischern 21 sind Absperrventile 25 bzw. 26 vorgesehen, die mit der Vertcilcrleiste 22 bzw. 23 verbunden sind. Manometer 27 bzw. 28 zeigen den Stickstoff- bzw. Schwcfeldioxyddruck nach den Absperrventilen 25 bzw. 26 an. Zwischen der Stickstofflci ung und der Schwefeldioxydlei- tung ist ein Absperrventil 29 zur Spülung vorgesehen, dem ein Rückschlagventil 30 nachge- schaltet ist. Hochgenaue Mengendurchflußmcsscr 31 für Stickstoff und 32 für Schwcfeldioxyd dienen zur Einstellung eines genauen Mengenverhältnisses der beiden Gase. Den Men- gen urchflußmesscrn 31 und 32 sind Filter 33 und 34 vorgeschaltet. Über weitere Absperrventile 35 und 36 und ein Rückschlagventil 37 in der Stickstoffleitung werden die Gase in eine Versorgungsleitung 38 zusammengeführt, die mit einem Manometer 39 und einem Absperrventil 40 versehen ist. Eine Spüllcitung 41 mit einem Abspenventil 42 dient zur Vermeidung von Umweltbelastungen bei Wartungsarbeiten oder dgl.The individual mixers 21 are supplied with nitrogen via a first vertical bar 22 and with sulfur dioxide via a second vertical bar 23. A third vertical bar 24 is used to connect the mixers 21 to the exhaust manifold line 19. Shut-off valves 25 and 26 are provided in the individual mixers 21, which are connected to the vertical bar 22 and 23, respectively. Pressure gauges 27 and 28 indicate the nitrogen and sulfur dioxide pressure after the shut-off valves 25 and 26, respectively. A shutoff valve 29 for purging is provided between the nitrogen line and the sulfur dioxide line, which is followed by a check valve 30. Highly precise mass flow rate measurements 31 for nitrogen and 32 for sulfur dioxide serve to set a precise ratio of the two gases. Filters 33 and 34 are connected upstream of the flow measurements 31 and 32. Via further shut-off valves 35 and 36 and a check valve 37 in the nitrogen line, the gases are brought together into a supply line 38, which is provided with a pressure gauge 39 and a shut-off valve 40. A flushing line 41 with a shut-off valve 42 serves to avoid environmental pollution during maintenance work or the like.
Die gesamte Anordnung, die in der Fig. dargestellt ist, ist erfindungsgemäß in einem klimatisierten Raum angeordnet, der auf einer Temperatur von etwa 30°C gehalten wird. Auf diese Weise kann das Mischungsverhältnis der Gase auf einem genau vorbestimmten Wert gehalten werden und eine gute Durchmischung gewährleistet werden.The entire arrangement, which is shown in the figure, is arranged according to the invention in an air-conditioned room, which is kept at a temperature of about 30 ° C. In this way, the mixing ratio of the gases can be kept at a precisely predetermined value and good mixing can be ensured.
Bei den einzelnen Verbrauchern können nicht dargestellte Mcngcnrcgler vorgesehen sein, die jedoch nur die zugeführte Menge des Gasgemisches, nicht aber die Zusammensetzung des Gases beeinflussen. Die vorliegende Erfindung ermöglicht somit nicht nur eine Kostenersparnis, sondern auch eine wesentliche Verringerung der Umweltbelastung und einen besonders sicheren Betrieb beim Umgang mit Magnesiumschmelzen. Mcngcnrcgler, not shown, can be provided for the individual consumers, but these only influence the quantity of the gas mixture supplied and not the composition of the gas. The present invention thus not only enables cost savings, but also a significant reduction in environmental pollution and particularly safe operation when handling magnesium melts.

Claims

P A T E N T A N S P R Ü C H E PATENT CLAIMS
1. Verfahren zum Betrieb von Ofenanlagcn für Magncsiumlegierungcn, bei dem eine Badoberfläche mit einem Schutzgas abgedeckt wird, das eine Schwefelverbindung enthält, dadurch gekennzeichnet, daß als Schutzgas ein Gemisch von S02 und einem Inertgas verwendet wird, wobei der Volumsanteil von SO, genau auf einen Wert eingestellt wird, der in einem Bereich zwischen 0,3 % und 1,5 %, vorzugsweise zwischen 0,5 % und 1 ,0 % liegt.1. A method of operating furnace system for Magncsiumlegnungcn, in which a bath surface is covered with a protective gas containing a sulfur compound, characterized in that a mixture of S0 2 and an inert gas is used as the protective gas, the volume fraction of SO, exactly a value is set which is in a range between 0.3% and 1.5%, preferably between 0.5% and 1.0%.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß als Inertgas Stickstoff verwendet wird.2. The method according to claim 1, characterized in that nitrogen is used as the inert gas.
3. Verfahren nach einem der Ansprüche 1 oder 2, dadurch gekennzeichnet, daß die Mischung von S02 und dem Inertgas in einem klimatisiertem Raum erfolgt, dessen Temperatur oberhalb von 22°C und vorzugsweise in einem Bereich zwischen 25°C und 35°C gehalten wird.3. The method according to any one of claims 1 or 2, characterized in that the mixing of S0 2 and the inert gas takes place in an air-conditioned room, the temperature of which is kept above 22 ° C and preferably in a range between 25 ° C and 35 ° C becomes.
4. Vorrichtung zur Erzeugung eines Schutzgases für Ofenanlagcn für Magncsiumlegierungcn mit einem Vorratsbehältcr (2) für eine Schwefelvcrbindung, einem Vorratsbehältcr (9) für ein Inertgas und einer Mischcinrichtung (21), dadurch gekennzeichnet, daß die Mischeinrichtung (21) zur genauen Durchflußrcgelung von S02 und Stickstoff ausgebildet ist und in einem klimatisierten Raum angeordnet ist.4. Device for producing a protective gas for furnace plant for Magncsium alloycn with a reservoir (2) for a sulfur bond, a reservoir (9) for an inert gas and a mixing device (21), characterized in that the mixing device (21) for precise flow control of S0 2 and nitrogen is formed and is arranged in an air-conditioned room.
5. Vorrichtung nach Anspruch 4, dadurcii gekennzeichnet, daß der klimatisierte Raum auf einer Temperatur von mehr als 22°C, vorzugsweise auf einer Temperatur zwischen 25°C und 35°C gehalten wird.5. The device according to claim 4, dadurcii characterized in that the air-conditioned room is kept at a temperature of more than 22 ° C, preferably at a temperature between 25 ° C and 35 ° C.
6. Vorrichtung nach einem der Ansprüche 4 oder 5, dadurch gekennzeichnet, daß Spüllci- tungen ( 10, 13, 41 ) und -ventile zum Spülen der nonnalcrwcisc S02-führcndcn Anla- genteilc vorgesehen sind. 6. Device according to one of claims 4 or 5, characterized in that flushing lines (10, 13, 41) and valves are provided for flushing the normal S0 2 -conducting system parts.
EP98955253A 1997-11-24 1998-11-12 Operation method of furnace equipment for magnesium alloys Expired - Lifetime EP1044285B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AT72997U 1997-11-24
AT0072997U AT2420U1 (en) 1997-11-24 1997-11-24 METHOD FOR THE OPERATION OF OVEN PLANTS FOR MAGNESIUM ALLOYS
PCT/AT1998/000279 WO1999027144A1 (en) 1997-11-24 1998-11-12 Operation method of furnace equipment for magnesium alloys

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EP1044285A1 true EP1044285A1 (en) 2000-10-18
EP1044285B1 EP1044285B1 (en) 2001-08-29

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EP (1) EP1044285B1 (en)
JP (1) JP2001524599A (en)
AT (2) AT2420U1 (en)
AU (1) AU744178B2 (en)
BR (1) BR9814891A (en)
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US6783487B2 (en) 2001-04-13 2004-08-31 Kimberly-Clark Worldwide, Inc. Pant-type personal care articles, and methods of making and using such personal care articles

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CN101132871B (en) * 2005-03-02 2011-04-20 日本重化学工业株式会社 Method of melting alloy containing high-vapor-pressure metal
JP2006258347A (en) * 2005-03-16 2006-09-28 Taiyo Nippon Sanso Corp Magnesium dissolution device and method for supplying cover gas thereto

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US1898969A (en) * 1932-03-21 1933-02-21 Dow Chemical Co Method of protecting magnesium and its alloys at elevated temperatures
DE2018407A1 (en) * 1969-05-05 1971-02-25 Fruehling J Protective atmosphere for magnesium and magnesium alloys
AT389477B (en) * 1981-03-10 1989-12-11 Linde Ag APPLICATION OF A METHOD FOR PROTECTING THE BATH SURFACE OF A METAL MELT
US5087485A (en) * 1990-08-14 1992-02-11 Texas Instruments Incorporated Isopropanol catalyst for copper chemical vapor deposition
DE4203193C2 (en) * 1992-02-05 1999-09-30 Inst Werkstoffkunde Uni Hannov Method and device for handling magnesium and magnesium alloy melts
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6783487B2 (en) 2001-04-13 2004-08-31 Kimberly-Clark Worldwide, Inc. Pant-type personal care articles, and methods of making and using such personal care articles

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AU1218399A (en) 1999-06-15
AT2420U1 (en) 1998-10-27
ES2162479T3 (en) 2001-12-16
AU744178B2 (en) 2002-02-14
US6527826B1 (en) 2003-03-04
ATE204919T1 (en) 2001-09-15
CA2311361A1 (en) 1999-06-03
JP2001524599A (en) 2001-12-04
BR9814891A (en) 2000-10-03
WO1999027144A1 (en) 1999-06-03
EP1044285B1 (en) 2001-08-29

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