EP0019876B1 - Electrically operated device for the heating of metals and/or salts in the molten state, and of solutions - Google Patents

Electrically operated device for the heating of metals and/or salts in the molten state, and of solutions Download PDF

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Publication number
EP0019876B1
EP0019876B1 EP80102887A EP80102887A EP0019876B1 EP 0019876 B1 EP0019876 B1 EP 0019876B1 EP 80102887 A EP80102887 A EP 80102887A EP 80102887 A EP80102887 A EP 80102887A EP 0019876 B1 EP0019876 B1 EP 0019876B1
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EP
European Patent Office
Prior art keywords
heating member
bath
electrode
heated
contact material
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.)
Expired
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EP80102887A
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German (de)
French (fr)
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EP0019876A1 (en
Inventor
Felicjan Biolik
Adam Lukasik
Zygmunt Morys
Stanislaw Walawender
Szczepan Galazka
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Biuro Projektow Przemyslu Metali Niezelaznych "Bipromet"
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Biuro Projektow Przemyslu Metali Niezelaznych "Bipromet"
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Priority to AT80102887T priority Critical patent/ATE16550T1/en
Publication of EP0019876A1 publication Critical patent/EP0019876A1/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/60—Heating arrangements wherein the heating current flows through granular powdered or fluid material, e.g. for salt-bath furnace, electrolytic heating
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/62—Heating elements specially adapted for furnaces

Definitions

  • the invention relates to an electrical device for heating metals and / or salts in the molten state and of solutions, with direct heating of the bath by means of resistance heating elements partially immersed therein.
  • the radiators are in the form of one or more partition walls, preferably parallel to in electrodes are arranged on the floor or in the walls of the melting tank.
  • These partitions made from a plate made of ceramic material separate the melting tank into two or more parts.
  • the plate has a section at the top which has a higher electrical resistance than the rest of the plate section.
  • the radiators can also be installed in the walls or in the bottom of the melting tank and touch the metal strip with at least one surface.
  • radiators made entirely from homogeneous material of a certain porosity are known in the form of vessels, which protrude from the heated bath and are exposed to the effect of the furnace atmosphere exhibit and are therefore subject to rapid aging, resistance change and cracks.
  • the unit performance of these radiators is limited in terms of the design technology. Short circuits in the parts of the radiators protruding from the bath, which are caused by accidental deposition of the metal insert and / or contact material as well as by overheating due to the creation of current channels at some points on the surface of the protruding parts of the radiator mentioned, can quickly destroy the radiators.
  • a single contact material made of liquid metal generates practically no additional amount of heat and causes corrosion of the metal electrodes accommodated in it, which means that very advantageous metal electrodes cannot be used.
  • a first embodiment of the invention is that in an electrical device for the direct heating of metals and / or salts in the molten state and of solutions with at least one resistance heating element partially immersed in the bath to be heated in the form of a vessel in which a contact substance is introduced , into which at least one electrode is inserted, by means of which, in cooperation with at least one counterelectrode acting on the bath, a voltage potential is applied between the contact material, the heating element and the bath, according to the invention it is provided that the heating element comprises at least two permanently connected fittings, the fittings consist of different materials with different physical and / or chemical properties.
  • a further exemplary embodiment according to the invention relates to a device for the direct heating of metals and / or salts in the molten state and of solutions with at least one resistance heating element partially immersed in the bath to be heated in the form of a vessel in which a contact substance is introduced and with At least one electrode is introduced, by means of which, in cooperation with at least one counterelectrode, a voltage potential is applied between the contact substance, the heating element and the bath, which is characterized in that a heating element is provided in the form of a double vessel, which forms a series connection of two individual heating elements and on both sides a wall which divides the bath to be heated into two parts which are insulated from one another and is immersed in the bath to be heated, the two electrodes being arranged on one and on the other side of the partition (FIG. 14).
  • a third embodiment of the invention is to be seen in the fact that in a device for the direct heating of metals and / or salts in the molten state and of solutions with at least one resistance heating element in the form of a vessel in which a contact substance is introduced and which is partially immersed in the bath to be heated is inserted into the at least one electrode, by means of which, in cooperation with at least one counterelectrode acting on the bath, a voltage potential is applied between the contact substance, the heating element and the bath, the invention provides that the electrically active surface of the heating element is at least partially coated a material which is resistant to the chemical action of the feed material and / or of contact material is covered (FIG. 13).
  • a fourth device for the direct heating of metals and / or salts in the molten state and of solutions with at least one resistance heating element in the form of a partition wall which is partially immersed in the bath to be heated and which is assigned at least one electrode, by means of which, in cooperation with at least one counter electrode acting in the bath Voltage potential is applied between the radiator and the bath, characterized in that the partition is tubular and the electrode installed in the interior of the tube performs the function of a contact substance (Fig. 12).
  • a fifth embodiment of the invention is that in a device for direct heating of metals and / or salts in the molten state and solutions with at least one resistance heater partially immersed in the bath to be heated, a contact substance which interacts with this resistance heater and into which at least one electrode is introduced is, by means of which, in cooperation with at least one counterelectrode acting on the bath, a voltage potential is applied between the contact substance, the radiator and the bath, according to the invention it is provided that the radiator is in the form of bodies accommodated within a limiting ring, the bodies having a layer of a Contact material are covered with a smaller density in relation to the density of the material of the bath to be heated and the material of the radiator (Fig. 10 and 11).
  • the radiators are made of preferably sintered materials which have a specific resistance at the operating temperature of below 100 ⁇ m, preferably within the limits of 0.001 ... 2.5 ⁇ m, and a porosity within the limits of 0 ... 30%.
  • the contact materials are current-conducting materials with a specific resistance of less than 200 ⁇ m.
  • the radiators in the form of a vessel or a partition have any cross-section, the height of the radiators being up to 2 m, the vessel wall thickness or partition wall thickness being up to 0.2 m, and the electrically active area being up to 2 m 2 .
  • the radiators are made from a homogeneous material in the form of a uniform fitting or from firmly connected fittings.
  • the surfaces of the radiators can also be partially coated, preferably with a thickness of 0.1 ... 3 mm, with respect to the chemical action of the feed material or the contact-resistant material.
  • the advantages of the device according to the invention include a more extensive area of application, in particular for heating metals and salts in the molten state and of solutions, and for melting metals and salts; a high load capacity of the radiators due to the use of a shape of the radiator corresponding to the given process method and a corresponding method for their production, the use of a corresponding immersion depth of the heating elements in the bath to be heated, the series-parallel or series connection of the contact materials in the circuit of the Radiator, the heating of the areas of the heating elements protruding from the bath to be heated, the use of materials suitable for the given process method for the radiators and the contact materials, an enlarged electrically active surface of the heating elements by accommodating a heating element inside another heating element and the use an appropriate power source for the given process engineering; a long service life of the electrodes and power supply lines due to the use of materials or protective atmospheres appropriate for the given process; the removal of the upper power supply lines due to the use of radiators in the form of a double vessel; the ease of starting
  • Fig. 1 of the device comprises a vessel consisting of walls 1 made of a ceramic material, which together with the bottom 2 forms the chamber 3 of the device.
  • the wall 4 separates the chamber 3 into a stand-off chamber and a melting chamber.
  • the chamber 3 is partially filled with the bath 5, here metal, in the molten state.
  • Floating in the metal 5 are two radiators 7 suspended under the float 6, which are in the form of vessels partially filled with the molten metal 8 and the molten salt 9, which function as contact materials between the iron electrode 10 immersed in the molten salt 9 and a surface of the radiator 7 meet.
  • a graphite electrode 11 is installed in the bottom 2 of the chamber 3 in such a way that one of its surfaces is connected to the supporting structure of the device, while the other surface is in contact with the metal 5, which on the other hand surrounds the radiators 7.
  • the electric current flows from the electrode 10 through the molten salt 9, the molten metal 8, the walls of the radiator under the influence of the voltage difference, which is applied to the electrode 10 by means of the current lead 12 and to the electrode 11 by means of the current lead 13 7 and the metal 5 to the electrode 11.
  • the heater 7 is made of nitrided silicon carbide.
  • the outer and inner surfaces of the radiator 7 are covered with a thin layer of carbon paste 15.
  • Metals 8 and 5 are aluminum.
  • Salt 9 is a mixture of calcium and sodium chloride.
  • the float 6 is made of light kaolin fabric.
  • the device according to the embodiment of the invention described above works in the following way. After preheating the chamber 3 of the device by means of an additional radiator and introducing partially molten metal into the bath 5, the radiators 7 filled with molten metal 8 and molten salt 9 become the melt while simultaneously connecting the electrodes 10 and the power supply lines 12 immersed. A voltage is applied to the current leads 12 and 13 led outwards from the device from a three-phase source, the phase voltage of phase R being applied to the first heating element 7 and that of phase S being applied to the second heating element 7. The current flowing under the action of the applied voltages through the walls of the radiators 7 and the layer of the molten salt 9 generates the necessary heat which is transferred to the metal strip 5.
  • the insert material is introduced into the metal strip 5 in the solid state in order to melt it. After the metal melting process has ended and the melt has come to a standstill, the device is emptied by partially tilting it, by pumping it out, or through a drain opening arranged in the bottom or in the wall of the chamber 3.
  • the start-up of the device from the cold state in the case in which the feed is only introduced in the solid state, is carried out by means of an additional heating element, which works until the first solder or the first batch of the feed is melted, or by means of on the fixed insert heating element 7 causes, the surfaces of the radiators 7 abut the insert 5 and via the carbon paste on the metal 8, and the electrode 10 with the metal 8 and the electrode 11 are in contact with the insert 5.
  • Fig. Shows a heater 7, at the upper edges of the ring 14 made of aluminum silicate is fixed by sintering.
  • FIG. 7 shows a heater 7 made from two shaped pieces 16, 17 connected by sintering, the material of the shaped piece 17 having a lower electrical conductivity than that of the shaped piece 16.
  • FIG. 8 shows a heating element 7 made from three shaped pieces interconnected by sintering.
  • radiator 9 shows two vessel-shaped radiators, which are immersed in the metal 5 due to a weight 18, one radiator 7 being accommodated in the other radiator 7 and both the space between the radiators 7 and the inner radiator 7 partly with metal 8 are filled.
  • Metals 8 and 5 are zinc.
  • the electrodes 10 and 11 are made of graphite and the weight 18 is made of cement-fireclay reinforced with steel rods.
  • the two radiators 7, the inner and the outer, are each made of nitrided silicon carbide.
  • the 10 shows four cuboidal radiators 7 floating freely in the metal 5 within the limiting ring 19, the radiators 7 being covered with a layer of molten salt 9. Under the influence of the potential difference applied to the electrodes 10, 11, the current flows from the electrode 10 in parallel through the salt 9 and the heating elements 7 to the metal 5 and finally to the electrode 11.
  • the metal 5 is an alloy of zinc and aluminum.
  • Salt 9 is a mixture of calcium and sodium chloride.
  • the electrode 10 is made of iron, the electrode 11 of graphite.
  • the limiting ring 19 consists of fireclay material.
  • the heater 7 is made of nitrided silicon carbide.
  • the start of the device from the cold to Stand is carried out by means of a radiator 7 placed on the fixed insert 5, the surfaces of the radiators 7 being in contact with the insert and the electrode 10 by means of carbon paste, while the electrode 11 is in contact with the insert 5.
  • nitrogen is introduced into the chamber 3, which protects the carbon paste against oxidation.
  • the contact substance 9 is introduced into the limiting ring 19.
  • Fig. 11 shows three cuboid radiators 7 floating freely in the metal 5 within the limiting ring 19.
  • the radiators 7 are covered with a metal layer 8 which is separated from the metal 5 by a layer of molten salt 9, the layer of the molten salt Salt 9 extends below the upper edges of the radiators 7.
  • the metal 8 is an aluminum alloy
  • the metal 5 is an aluminum bronze.
  • the electrodes 10 and 11 consist of graphite and are covered with a layer of silicon carbide discharged from the gas phase.
  • Salt 9 is a mixture of sodium carbonate and chloride.
  • the radiators 7 are made of nitrided silicon carbide, and the limiting ring 19 is made of fireclay material.
  • Fig. 12 shows a conical tubular heater 7, which is suspended in the bath 5, namely here the molten salt, by means of the holder 20 and the rope 21 on the supporting structure of the device such that the heater 7 is always a constant, from the bath level of the salt has an independent immersion depth.
  • the electrode 10 connected to the power supply line 12 is in direct contact with a surface of the radiator 7.
  • the conical part of the electrode 10 simultaneously fulfills the function of the contact substance.
  • the outer surface of the radiator 7 is covered with a thin layer of a fabric 15.
  • the salt 5 is a mixture of barium and calcium chloride .
  • the substance 15 consists of a silicon carbide applied from the gas phase.
  • the electrode 10 is made of reactive sintered silicon carbide.
  • the electrode 11 consists of graphite with a thin layer of silicon carbide applied from the gas phase.
  • the holder 20 and the rope 21 are made of alloy steel, and the heating element 7 is made of nitrided silicon carbide.
  • the 13 shows a vessel-shaped radiator 7 immersed in an aqueous solution 5 of sulfuric acid and suspended under a float 6, the interior of the radiator 7 being filled with metal 8.
  • the heater 7 is covered on the outside with a thin layer of a fabric 15.
  • the metal 8 is wood metal.
  • the float 6 consists of polyethylene, the electrode 10 made of graphite, the electrode 11 made of acid-resistant steel and the float 22 made of graphite.
  • the heater 7 is made of sintered, graphite-based material.
  • the layer 15 consists of silicon carbide discharged from the gas phase.
  • FIG. 14 shows a heating element 7 in the form of a double egg vessel, which is partly immersed in the metal 5 and partly filled with metal 8, and the wall 23 separates the bath 5 into two parts which are insulated from one another.
  • the Radiator 7 consists of a sintered material based on zirconium dioxide.
  • the material of the left vessel have different physical and chemical properties than that of the right vessel, depending on the different height of the two vessels.
  • the electrodes 10 and 11 are made of graphite.
  • the wall 23 is made of a material based on corundum.

Abstract

1. An electrical device for the direct heating of metals and/or salts in the molten state and solutions having at least one resistence heating member (7) in the form of a vessel partially immersed in the bath (5) to be heated and in which a contact material (8, 9) is disposed, in which material there is inserted an electrode (10) by means of which a voltage potential between the contact material, the heating member and the bath is produced in cooperation with at least one counter-electrode (13) acting on the bath (5), characterised in that the heating member (7) comprises at least two permanently connected moulded components, these components consisting of different materials with different physical and/or chemical properties.

Description

Die Erfindung betrifft eine elektrische Einrichtung zur Erhitzung von Metallen und/oder Salzen im geschmolzenen Zustand sowie von Lösungen, mit direkter Erhitzung des Bades mittels darin teilweise eingetauchter Widerstandsheizkörper.The invention relates to an electrical device for heating metals and / or salts in the molten state and of solutions, with direct heating of the bath by means of resistance heating elements partially immersed therein.

Bei den bisher bekannten elektrischen Heizeinrichtungen, bei denen die in den Heizkörpern erzeugte Wärme direkt in das Bad übertragen wird, haben, wie in der polnischen Patentschrift Nr. 81 320 dargestellt, die Heizkörper die Form von einer oder mehreren Trennwänden, die vorzugsweise parallel zu in dem Boden oder in den Wänden der Schmelzwanne untergebrachten Elektroden angeordnet sind. Diese aus einer Platte aus Keramikwerkstoff gefertigten Trennwände trennen die Schmelzwanne in zwei oder mehrere Teile. Die Platte weist an der Oberseite einen Abschnitt auf, der einen höheren elektrischen Widerstand besitzt als der übrige Plattenabschnitt. Die Heizkörper können aber auch in den Wänden oder in dem Boden der Schmelzwanne eingebaut sein und mit mindestens einer Fläche das Metallband berühren.In the previously known electric heating devices, in which the heat generated in the radiators is transferred directly to the bathroom, as shown in Polish Patent No. 81 320, the radiators are in the form of one or more partition walls, preferably parallel to in electrodes are arranged on the floor or in the walls of the melting tank. These partitions made from a plate made of ceramic material separate the melting tank into two or more parts. The plate has a section at the top which has a higher electrical resistance than the rest of the plate section. The radiators can also be installed in the walls or in the bottom of the melting tank and touch the metal strip with at least one surface.

Durch die US-PS 1 971 025 und in ähnlicher Weise durch die DE-PS 27 06 811 sind vollständig aus homogenem Stoff einer bestimmten Porosität hergestellte Heizkörper in Form von Gefäßen bekannt, die einen aus dem erwärmten Bad herausragenden, der Wirkung der Ofenatmosphäre ausgesetzten Teil aufweisen und daher einer schnellen Alterungs-, einer Widerstandsänderung und Rissen unterliegen. Die Einheitsleistung dieser Heizkörper ist in Hinsicht auf die Ausführungstechnologie beschränkt. Kurzschlüsse in den aus dem Bad herausragenden Teilen der Heizkörper, die durch zufälliges Absetzen des metallischen Einsatzgutes und/oder Kontaktmaterials sowie durch Überhitzung aufgrund von entstehenden Stromkanälen an manchen Stellen der Oberfläche der herausragenden Teile des erwähnten Heizkörpers verursacht werden, können die Heizkörper rasch zerstören. Ein einziges, aus flüssigem Metall bestehenden Kontaktmaterial erzeugt praktisch keine zusätzliche Wärmemenge und bewirkt eine Korrosion der in ihm untergebrachten Metallelektroden, wodurch sehr vorteilhafte Metallelektroden nicht angewandt werden können.From US Pat. No. 1 971 025 and similarly from DE-PS 27 06 811, radiators made entirely from homogeneous material of a certain porosity are known in the form of vessels, which protrude from the heated bath and are exposed to the effect of the furnace atmosphere exhibit and are therefore subject to rapid aging, resistance change and cracks. The unit performance of these radiators is limited in terms of the design technology. Short circuits in the parts of the radiators protruding from the bath, which are caused by accidental deposition of the metal insert and / or contact material as well as by overheating due to the creation of current channels at some points on the surface of the protruding parts of the radiator mentioned, can quickly destroy the radiators. A single contact material made of liquid metal generates practically no additional amount of heat and causes corrosion of the metal electrodes accommodated in it, which means that very advantageous metal electrodes cannot be used.

Aufgabe der Erfindung ist es, die als bekannt vorausgesetzten Einrichtungen so weiterzubilden, daß eine Zerstörung des Widerstandsheizkörpers aufgrund chemischer und/oder physikalischer Angriffe oder aufgrund thermischer Spannungen weitgehend vermieden ist.The object of the invention is to further develop the devices that are known as known so that destruction of the resistance heating element due to chemical and / or physical attacks or due to thermal stresses is largely avoided.

Diese Aufgabe wird durch die in den Ansprüchen gekennzeichnete Erfindung gelöst.This object is achieved by the invention characterized in the claims.

Eine erste Ausführungsform der Erfindung besteht darin, daß bei einer elektrischen Einrichtung zur direkten Erwärmung von Metallen und/ oder Salzen im geschmolzenen Zustand sowie von Lösungen mit mindestens einem in das zu erwärmende Bad teilweise eingetauchten Widerstandsheizkörper in Form eines Gefäßes, in dem ein Kontaktstoff eingebracht ist, in den mindestens eine Elektrode eingeführt ist, mittels der in Zusammenarbeit mit mindestens einer auf das Bad wirkenden Gegenelektrode ein Spannungspotential zwischen Kontakstoff, Heizkörper und Bad angelegt wird, erfindungsgemäß vorgesehen ist, daß der Heizkörper mindestens zwei dauerhaft miteinander verbundene Formstücke umfaßt, wobei die Formstücke aus verschiedenen Werkstoffen mit unterschiedlichen physikalischen und/oder chemischen Eigenschaften bestehen.A first embodiment of the invention is that in an electrical device for the direct heating of metals and / or salts in the molten state and of solutions with at least one resistance heating element partially immersed in the bath to be heated in the form of a vessel in which a contact substance is introduced , into which at least one electrode is inserted, by means of which, in cooperation with at least one counterelectrode acting on the bath, a voltage potential is applied between the contact material, the heating element and the bath, according to the invention it is provided that the heating element comprises at least two permanently connected fittings, the fittings consist of different materials with different physical and / or chemical properties.

Zweckmäßige Weiterbildungen dieser Einrichtung ergeben sich aus den Patentansprüchen 2-5.Appropriate further developments of this device result from the claims 2-5.

Ein weiteres Ausführungsbeispiel nach der Erfindung bezieht sich auf eine Einrichtung zur direkten Erwärmung von Metallen und/oder Salzen im geschmolzenen Zustand sowie von Lösungen mit mindestens einem in das zu erwärmende Bad teilweise eingetauchten Widerstandsheizkörper in Form eines Gefäßes, in dem ein Kontaktstoff eingebracht ist und mit mindestens einer Elektrode eingeführt ist, mittels der in Zusammenarbeit mit mindestens einer Gegenelektrode ein Spannungspotential zwischen Kontaktstoff, Heizkörper und Bad angelegt wird, das dadurch gekennzeichnet ist, daß ein Heizkörper in Form eines Doppelgefäßes vorgesehen ist, welches eine Reihenschaltung von zwei einzelnen Heizkörpern bildet und beidseits einer Wand, die das zu erhitzende Bad in zwei voneinander isolierte Teile teilt, in das zu erhitzende Bad eingetaucht ist, wobei die beiden Elektroden auf der einen und auf der anderen Seite der Trennwand angeordnet sind (Fig. 14).A further exemplary embodiment according to the invention relates to a device for the direct heating of metals and / or salts in the molten state and of solutions with at least one resistance heating element partially immersed in the bath to be heated in the form of a vessel in which a contact substance is introduced and with At least one electrode is introduced, by means of which, in cooperation with at least one counterelectrode, a voltage potential is applied between the contact substance, the heating element and the bath, which is characterized in that a heating element is provided in the form of a double vessel, which forms a series connection of two individual heating elements and on both sides a wall which divides the bath to be heated into two parts which are insulated from one another and is immersed in the bath to be heated, the two electrodes being arranged on one and on the other side of the partition (FIG. 14).

Eine dritte Ausführungsform der Erfindung ist darin zu sehen, daß bei einer Einrichtung zur direkten Erwärmung von Metallen und/oder Salzen im geschmolzenen Zustand sowie von Lösungen mit mindestens einem in das zu erwärmende Bad teilweise eingetauchten Widerstandsheizkörper in Form eines Gefäßes, in dem ein Kontaktstoff eingebracht ist, in den mindestens eine Elektrode eingeführt ist, mittels der in Zusammenarbeit mit mindestens einer auf das Bad wirkenden Gegenelektrode ein Spannungspotential zwischen Kontaktstoff, Heizkörper und Bad angelegt wird, erfindungsgemäß vorgesehen ist, daß die elektrisch aktive Fläche des Heizkörpers mindestens zum Teil mit einer Schicht eines gegenüber der chemischen Einwirkung des Einsatzgutes und/oder von Kontaktstoff beständigen Werkstoffs bedeckt ist (Fig. 13).A third embodiment of the invention is to be seen in the fact that in a device for the direct heating of metals and / or salts in the molten state and of solutions with at least one resistance heating element in the form of a vessel in which a contact substance is introduced and which is partially immersed in the bath to be heated is inserted into the at least one electrode, by means of which, in cooperation with at least one counterelectrode acting on the bath, a voltage potential is applied between the contact substance, the heating element and the bath, the invention provides that the electrically active surface of the heating element is at least partially coated a material which is resistant to the chemical action of the feed material and / or of contact material is covered (FIG. 13).

Eine vierte erfindungsgemäße Einrichtung zur direkten Erwärmung von Metallen und/oder Salzen im geschmolzenen Zustand sowie von Lösungen mit mindestens einem in das zu erwärmende Bad teilweise eingetauchten Widerstandsheizkörper in Form einer Trennwand, der mindestens eine Elektrode zugeordnet ist, mittels der in Zusammenarbeit mit mindestens einer auf das Bad wirkenden Gegenelektrode ein Spannungspotential zwischen Heizkörper und Bad angelegt wird, ist dadurch gekennzeichnet, daß die Trennwand rohrförmig ausgebildet ist und die im Innern des Rohrs eingebaute Elektrode die Funktion eines Kontaktstoffs erfüllt (Fig. 12).A fourth device according to the invention for the direct heating of metals and / or salts in the molten state and of solutions with at least one resistance heating element in the form of a partition wall which is partially immersed in the bath to be heated and which is assigned at least one electrode, by means of which, in cooperation with at least one counter electrode acting in the bath Voltage potential is applied between the radiator and the bath, characterized in that the partition is tubular and the electrode installed in the interior of the tube performs the function of a contact substance (Fig. 12).

Eine fünfte Ausführungsform der Erfindung besteht darin, daß bei einer Einrichtung zur direkten Erwärmung von Metallen und/oder Salzen im geschmolzenen Zustand sowie Lösungen mit mindestens einem teilweise in dem zu erwärmenden Bad eingetauchten Widerstandsheizkörper einem mit diesem Widerstandsheizkörper zusammenwirkenden Kontaktstoff, in den mindestens eine Elektrode eingeführt ist, mittels der in Zusammenarbeit mit mindestens einer auf das Bad wirkenden Gegenelektrode ein Spannungspotential zwischen Kontaktstoff, Heizkörper und Bad angelegt wird, erfindungsgemäß vorgesehen ist, daß der Heizkörper in Form von innerhalb eines Begrenzungsrings untergebrachten Körpern ausgebildet ist, wobei die Körper mit einer Schicht eines Kontaktstoffs mit einer in bezug auf die Dichte des Werkstoffs des zu erhitzenden Bades und des Werkstoffs des Heizkörpers kleineren Dichte bedeckt sind (Fig. 10 und 11).A fifth embodiment of the invention is that in a device for direct heating of metals and / or salts in the molten state and solutions with at least one resistance heater partially immersed in the bath to be heated, a contact substance which interacts with this resistance heater and into which at least one electrode is introduced is, by means of which, in cooperation with at least one counterelectrode acting on the bath, a voltage potential is applied between the contact substance, the radiator and the bath, according to the invention it is provided that the radiator is in the form of bodies accommodated within a limiting ring, the bodies having a layer of a Contact material are covered with a smaller density in relation to the density of the material of the bath to be heated and the material of the radiator (Fig. 10 and 11).

Schließlich ist bei einer elektrischen Einrichtung zur direkten Erwärmung von Metallen und/ oder Salzen im geschmolzenen Zustand sowie von Lösungen

  • mit mindestens einem in das zu erwärmende Bad teilweise eingetauchten Widerstandsheizkörper in Form eines Gefäßes,
  • in dem ein Kontaktstoff eingebracht ist,
  • in dem mindestens eine Elektrode eingeführt ist, mittels der in Zusammenarbeit mit mindestens einer auf das Bad wirkenden Gegenelektrode ein Spannungspotential zwischen Kontaktstoff, Heizkörper und Bad angelegt wird,
  • erfindungsgemäß vorgesehen, daß
  • der Heizkörper aus zwei Gefäßen besteht, ein Gefäß im Inneren des anderen untergebracht ist und der Raum zwischen den Gefäßen sowie das Innere des inneren Gefäßes zum Teil mit Kontaktstoff aufgefüllt sind, und daß die Gefäße zwischen der in den Kontaktstoff des inneren Gefäßes eingeführten Elektrode und der Gegenelektrode in Reihe liegen (Fig. 9).
Finally, an electrical device for the direct heating of metals and / or salts in the molten state and of solutions
  • with at least one resistance heating element in the form of a vessel, which is partially immersed in the bath to be heated,
  • in which a contact substance is introduced,
  • in which at least one electrode is inserted, by means of which, in cooperation with at least one counterelectrode acting on the bath, a voltage potential is applied between the contact substance, the radiator and the bath,
  • provided according to the invention that
  • the radiator consists of two vessels, one vessel is housed inside the other and the space between the vessels and the interior of the inner vessel are partially filled with contact material, and that the vessels between the electrode inserted into the contact material of the inner vessel and the Counter electrode are in series (Fig. 9).

Weitere zweckmäßige Ausbildungen dieser erfindungsgemäßen Einrichtungen ergeben sich aus den übrigen Patentansprüchen.Further expedient developments of these devices according to the invention result from the remaining claims.

Die Heizkörper sind aus vorzugsweise gesinterten Werkstoffen gefertigt, die einen spezifischen Widerstand bei der Betriebstemperatur von unterhalb 100 Ωm, vorzugsweise innerhalb der Grenzen von 0,001 ... 2,5 Ωm, und eine Porosität innerhalb der Grenzen von 0 ... 30% aufweisen.The radiators are made of preferably sintered materials which have a specific resistance at the operating temperature of below 100 Ωm, preferably within the limits of 0.001 ... 2.5 Ωm, and a porosity within the limits of 0 ... 30%.

Die Elektroden sind aus Werkstoffen gefertigt, deren spezifischer Widerstand mindestens 10mal niedriger ist als der der Heizkörperwerkstoffe.The electrodes are made of materials whose specific resistance is at least 10 times lower than that of the radiator materials.

Die Kontaktstoffe sind stromleitende Werkstoffe mit einem spezifischen Widerstand von unter 200 Ωm. Die Heizkörper in Form eines Gefäßes oder einer Trennwand weisen beliebigen Querschnitt auf, wobei die Höhe der Heizkörper bis 2 m, die Gefäßwanddicke oder Trennwanddicke bis 0,2 m, und die elekrisch aktive Fläche bis 2 m2 beträgt.The contact materials are current-conducting materials with a specific resistance of less than 200 Ωm. The radiators in the form of a vessel or a partition have any cross-section, the height of the radiators being up to 2 m, the vessel wall thickness or partition wall thickness being up to 0.2 m, and the electrically active area being up to 2 m 2 .

Die Heizkörper sind aus einem homogenen Werkstoff in Form eines einheitlichen Formstücks oder aus fest verbundenen Formstücken gefertigt. Die Oberflächen der Heizkörper können auch zum Teil, vorzugsweise mit einer Dicke von 0,1 ... 3 mm, in bezug auf die chemische Einwirkung des Einsatzguts oder der Kontaktstoffe beständigem Werkstoff beschichtet werden.The radiators are made from a homogeneous material in the form of a uniform fitting or from firmly connected fittings. The surfaces of the radiators can also be partially coated, preferably with a thickness of 0.1 ... 3 mm, with respect to the chemical action of the feed material or the contact-resistant material.

Die Vorteile der erfindungsgemäßen Einrichtung sind unter anderem ein umfangreicherer Anwendungsbereich, insbesondere zur Erhitzung von Metallen und Salzen im geschmolzenen Zustand und von Lösungen sowie zum Schmelzen von Metallen und Salzen; eine hohe Belastbarkeit der Heizkörper infolge der Anwendung einer dem gegebenen Prozeßverfahren entsprechenden Form der Heizkörper und eines entsprechenden Verfahrens zu deren Herstellung, der Anwendung einer entsprechenden Eintauchtiefe der Heizelemente in das zu erhitzende Bad, der Reihen-Parallel- oder Reihenschaltung der Kontaktstoffe in dem Stromkreis des Heizkörpers, der Erhitzung der aus dem zu erhitzenden Bad herausragenden Bereiche der Heizelemente, der Anwendung von für das gegebene Prozeßverfahren geeigneten Werkstoffen für die Heizkörper und die Kontaktstoffe, einer vergrößerten elektrisch aktiven Oberfläche der Heizelemente durch Unterbringung eines Heizelements im Inneren eines anderen Heizkörpers und des Einsatzes einer für die gegebene Verfahrenstechnik angemessenen Stromquelle; eine lange Standzeit der Elektroden und Stromzuleitungen infolge der Anwendung von für das gegebene Prozeßverfahren entsprechenden Werkstoffen bzw. Schutzatmosphären; die Beseitigung der oberen Stromzuleitungen aufgrund der Verwendung von Heizkörpern in Form eines Doppelgefäßes; die Einfachheit des Anlaufens der Einrichtung aus dem kalten Zustand infolge der Verbesserung der Kontakte der Heizkörper mit dem festen Einsatzgut mittels zusätzlicher Kontaktstoffe, vorzugsweise von pastöser Konsistenz; eine einfache Auslegung und Bedienung der Einrichtung als Ergebnis der Verwendung von mehreren Einbauarten der Heizkörper, der Elektroden und der Stromzuleitungen; sowie eine einfache Auswechselbarkeit der Heizelemente ohne die Notwendigkeit, die Einrichtung außer Betrieb zu setzen.The advantages of the device according to the invention include a more extensive area of application, in particular for heating metals and salts in the molten state and of solutions, and for melting metals and salts; a high load capacity of the radiators due to the use of a shape of the radiator corresponding to the given process method and a corresponding method for their production, the use of a corresponding immersion depth of the heating elements in the bath to be heated, the series-parallel or series connection of the contact materials in the circuit of the Radiator, the heating of the areas of the heating elements protruding from the bath to be heated, the use of materials suitable for the given process method for the radiators and the contact materials, an enlarged electrically active surface of the heating elements by accommodating a heating element inside another heating element and the use an appropriate power source for the given process engineering; a long service life of the electrodes and power supply lines due to the use of materials or protective atmospheres appropriate for the given process; the removal of the upper power supply lines due to the use of radiators in the form of a double vessel; the ease of starting the device from the cold state due to the improvement of the contacts of the radiators with the solid feed material by means of additional contact materials, preferably of a pasty consistency; simple design and operation of the device as a result of the use of several types of installation of the radiators, the electrodes and the power supply lines; as well as easy replacement of the heating elements without the need to shut down the device.

Die Erfindung wird nachstehend anhand von Ausführungsbeispielen näher erläutert. In der zugehörigen Zeichnung zeigt:

  • Fig. 1 eine erste Ausführungsform der Einrichtung im Querschnitt
  • Fig. 2 bis 8 Formen und Ausführungsarten der Heizkörper, und
  • Fig.9 bis 14 Einbauarten von Heizelementen und Elektroden in weitere Ausführungsformen der Einrichtung.
The invention is explained in more detail below on the basis of exemplary embodiments. In the accompanying drawing:
  • Fig. 1 shows a first embodiment of the device in cross section
  • Fig. 2 to 8 shapes and designs of the radiators, and
  • 9 to 14 types of installation of heating elements and electrodes in further embodiments of the device.

Das in Fig. 1 dargestellte Ausführungsbeispiel der erfindungsgemäßen Einrichtung umfaßt ein Gefäß, bestehend aus Wänden 1 aus einem keramischen Werkstoff, welche zusammen mit dem Boden 2 die Kammer 3 der Einrichtung bildet. Die Wand 4 trennt die Kammer 3 in eine Abstehkammer und eine Schmelzkammer. Die Kammer 3 ist zum Teil mit dem Bad 5, hier Metall, in geschmolzenem Zustand aufgefüllt.The embodiment shown in Fig. 1 of the device according to the invention comprises a vessel consisting of walls 1 made of a ceramic material, which together with the bottom 2 forms the chamber 3 of the device. The wall 4 separates the chamber 3 into a stand-off chamber and a melting chamber. The chamber 3 is partially filled with the bath 5, here metal, in the molten state.

Im Metall 5 schwimmen zwei unter dem Schwimmer 6 angehängte Heizkörper 7, welche die Form von zum Teil mit dem geschmolzenen Metall 8 und dem geschmolzenen Salz 9 gefüllten Gefäßen aufweisen, welche die Funktion von Kontaktstoffen zwischen der im geschmolzenen Salz 9 eingetauchten Eisenelektrode 10 und einer Oberfläche des Heizkörpers 7 erfüllen. Im Boden 2 der Kammer 3 ist eine Graphitelektrode 11 derart eingebaut, daß eine ihrer Flächen mit dem Tragwerk der Einrichtung verbunden ist, während die andere Fläche mit dem Metall 5 im Kontakt steht, das andererseits die Heizkörper 7 umgibt.Floating in the metal 5 are two radiators 7 suspended under the float 6, which are in the form of vessels partially filled with the molten metal 8 and the molten salt 9, which function as contact materials between the iron electrode 10 immersed in the molten salt 9 and a surface of the radiator 7 meet. A graphite electrode 11 is installed in the bottom 2 of the chamber 3 in such a way that one of its surfaces is connected to the supporting structure of the device, while the other surface is in contact with the metal 5, which on the other hand surrounds the radiators 7.

Der elektrische Strom fließt unter dem Einfluß des Spannungsunterschiedes, der mittels der Stromzuleitung 12 an die Elektrode 10 und mittels der Stromzuleitung 13 an die Elektrode 11 angelegt ist, von der Elektrode 10 durch das geschmolzene Salz 9, das geschmolzene Metall 8, die Wände des Heizkörpers 7 und das Metall 5 zur Elektrode 11.The electric current flows from the electrode 10 through the molten salt 9, the molten metal 8, the walls of the radiator under the influence of the voltage difference, which is applied to the electrode 10 by means of the current lead 12 and to the electrode 11 by means of the current lead 13 7 and the metal 5 to the electrode 11.

An den oberen Rändern des Heizkörpers 7 ist durch Sinterung der Ring 14 aus Aluminiumsilikatstoff befestigt. Der Heizkörper 7 ist aus nitridiertem Siliziumkarbid ausgeführt. Die äußeren und inneren Oberflächen des Heizkörpers 7 sind mit einer dünnen Schicht von Kohlenpaste 15 bedeckt. Die Metalle 8 und 5 sind Aluminium. Das Salz 9 ist eine Mischung vom Kalzium- und Natriumchlorid. Der Schwimmer 6 ist aus leichtem Kaolinstoff gefertigt.At the upper edges of the radiator 7, the ring 14 made of aluminum silicate is fixed by sintering. The heater 7 is made of nitrided silicon carbide. The outer and inner surfaces of the radiator 7 are covered with a thin layer of carbon paste 15. Metals 8 and 5 are aluminum. Salt 9 is a mixture of calcium and sodium chloride. The float 6 is made of light kaolin fabric.

Die Einrichtung gemäß dem oben beschriebenen Ausführungsbeispiel der Erfindung arbeitet auf folgende Weise. Nach einer Voraufwärmung der Kammer 3 der Einrichtung mittels eines zusätzlichen Heizkörpers und dem Einbringen von zum Teil geschmolzenem Metall in das Bad 5 werden die mit geschmolzenem Metall 8 und geschmolzenem Salz 9 aufgefüllten Heizkörper 7 unter gleichzeitigem Anschließen der Elektroden 10 und der Stromzuleitungen 12 in die Schmelze eingetaucht. An die nach außen aus der Einrichtung herausgeführten Stromzuleitungen 12 und 13 wird aus einer Drehstromquelle eine Spannung angelegt, wobei die Phasenspannung der Phase R an den ersten Heizkörper 7 und die der Phase S an den zweiten Heizkörper 7 angelegt wird. Der unter der Einwirkung der angelegten Spannungen durch die Wände der Heizkörper 7 und die Schicht des geschmolzenen 9 Salzes hindurchfließende Strom erzeugt die notwendige Wärme, welche auf das Metallband 5 übertragen wird. In das Metallband 5 wird das Einsatzgut im festen Zustand eingeführt, um dieses zu schmelzen. Nach Beendigung des Metallschmelzprozesses und dem Abstehen der Schmelze wird die Einrichtung durch teilweises Kippen derselben, durch Auspumpen, oder durch eine im Boden oder in der Wand der Kammer 3 angeordnete Ablaßöffnung entleert.The device according to the embodiment of the invention described above works in the following way. After preheating the chamber 3 of the device by means of an additional radiator and introducing partially molten metal into the bath 5, the radiators 7 filled with molten metal 8 and molten salt 9 become the melt while simultaneously connecting the electrodes 10 and the power supply lines 12 immersed. A voltage is applied to the current leads 12 and 13 led outwards from the device from a three-phase source, the phase voltage of phase R being applied to the first heating element 7 and that of phase S being applied to the second heating element 7. The current flowing under the action of the applied voltages through the walls of the radiators 7 and the layer of the molten salt 9 generates the necessary heat which is transferred to the metal strip 5. The insert material is introduced into the metal strip 5 in the solid state in order to melt it. After the metal melting process has ended and the melt has come to a standstill, the device is emptied by partially tilting it, by pumping it out, or through a drain opening arranged in the bottom or in the wall of the chamber 3.

Der Anlauf der Einrichtung aus kaltem Zustand in dem Fall, in dem das Einsatzgut ausschließlich im festen Zustande eingebracht wird, wird mittels eines zusätzlichen Heizkörpers, der bis zum Zeitpunkt des Schmelzens des ersten Lots bzw. der ersten Charge des Einsatzguts arbeitet, oder mittels auf dem festen Einsatzgut aufgestellter Heizkörper 7 bewirkt, wobei die Oberflächen der Heizkörper 7 an dem Einsatzgut 5 und über die Kohlenpaste an dem Metall 8 anliegen, und die Elektrode 10 mit dem Metall 8 und die Elektrode 11 mit dem Einsatzgut 5 im Kontakt stehen.The start-up of the device from the cold state, in the case in which the feed is only introduced in the solid state, is carried out by means of an additional heating element, which works until the first solder or the first batch of the feed is melted, or by means of on the fixed insert heating element 7 causes, the surfaces of the radiators 7 abut the insert 5 and via the carbon paste on the metal 8, and the electrode 10 with the metal 8 and the electrode 11 are in contact with the insert 5.

Die Fig. 2 bis 5 stellen nur allgemeine Formen der Heizkörper 7 dar, jeder aus verschiedenen Werkstoffen geformt und darauffolgend gesintert oder aus verschiedenen Teilen bestehend.2 to 5 represent only general shapes of the radiators 7, each formed from different materials and subsequently sintered or consisting of different parts.

Fig. zeigt einen Heizkörper 7, an dessen oberen Rändern durch Sinterung der Ring 14 aus Aluminiumsilikatstoff befestigt ist.Fig. Shows a heater 7, at the upper edges of the ring 14 made of aluminum silicate is fixed by sintering.

In Fig. 7 ist ein aus zwei, durch Sintern verbundene Formstücke 16, 17 ausgeführter Heizkörper 7 dargestellt, wobei der Werkstoff des Fomstücks 17 eine niedrigere elektrische Leitfähigkeit aufweist als die des Formstücks 16.FIG. 7 shows a heater 7 made from two shaped pieces 16, 17 connected by sintering, the material of the shaped piece 17 having a lower electrical conductivity than that of the shaped piece 16.

Fig. 8 zeigt einen aus drei, durch Sintern miteinander verbundene Formstücke ausgeführten Heizkörper 7.FIG. 8 shows a heating element 7 made from three shaped pieces interconnected by sintering.

In den Fig. 9 bis 14 sind die Einbauweisen der Heizkörper der erfindungsgemäßen Einrichtung dargestellt.9 to 14, the installation methods of the radiators of the device according to the invention are shown.

Fig. 9 zeigt zwei gefäßförmige Heizkörper, welche in das Metall 5 aufgrund eines Beschwerungsgewichts 18 eingetaucht sind, wobei ein Heizkörper 7 in dem anderen Heizkörper 7 untergebracht ist und sowohl der Raum zwischen den Heizkörpern 7 als auch der innere Heizkörper 7 zum Teil mit Metall 8 gefüllt sind. Die Metalle 8 und 5 sind Zink. Die Elektroden 10 und 11 sind aus Graphit und das Beschwerungsgewicht 18 ist aus mit Stahlstäben bewehrtem Zement-Schamottenstoff. Die beiden Heizkörper 7, der innere und der äußere, sind jeweils aus nitridiertem Siliziumkarbid gefertigt.9 shows two vessel-shaped radiators, which are immersed in the metal 5 due to a weight 18, one radiator 7 being accommodated in the other radiator 7 and both the space between the radiators 7 and the inner radiator 7 partly with metal 8 are filled. Metals 8 and 5 are zinc. The electrodes 10 and 11 are made of graphite and the weight 18 is made of cement-fireclay reinforced with steel rods. The two radiators 7, the inner and the outer, are each made of nitrided silicon carbide.

In Fig. 10 sind vier quaderförmige, frei im Metall 5 innerhalb des Begrenzungsrings 19 schwimmende Heizkörper 7 dargestellt, wobei die Heizkörper 7 mit einer Schicht von geschmolzenem Salz 9 bedeckt sind. Unter dem Einfluß des an die Elektroden 10, 11 angelegten Potentialunterschiedes fließt der Strom von der Elektrode 10 parallel durch das Salz 9 und die Heizkörper 7 zum Metall 5 und schließlich zur Elektrode 11. Das Metall 5 ist eine Legierung von Zink und Aluminium. Das Salz 9 ist eine Mischung von Kalzium- und Natriumchlorid. Die Elektrode 10 ist aus Eisen gefertigt, die Elektrode 11 aus Graphit. Der Begrenzungsring 19 besteht aus Schamottestoff. Der Heizkörper 7 ist aus nitridiertem Siliziumkarbid ausgeführt.10 shows four cuboidal radiators 7 floating freely in the metal 5 within the limiting ring 19, the radiators 7 being covered with a layer of molten salt 9. Under the influence of the potential difference applied to the electrodes 10, 11, the current flows from the electrode 10 in parallel through the salt 9 and the heating elements 7 to the metal 5 and finally to the electrode 11. The metal 5 is an alloy of zinc and aluminum. Salt 9 is a mixture of calcium and sodium chloride. The electrode 10 is made of iron, the electrode 11 of graphite. The limiting ring 19 consists of fireclay material. The heater 7 is made of nitrided silicon carbide.

Der Anlauf der Einrichtung aus dem kalten Zustand wird mittels auf das feste Einsatzgut 5 aufgesetzter Heizkörper 7 durchgeführt, wobei die Oberflächen der Heizkörper 7 mittels Kohlepaste an dem Einsatzgut und der Elektrode 10 anliegen, während die Elektrode 11 in Kontakt mit dem Einsatzgut 5 steht. Während der Anlaufzeit wird in die Kammer 3 Stickstoff eingeführt, der einen Schutz der Kohlenpaste gegen Oxidierung bildet. Nach dem Schmelzen des Einsatzgutes 5 wird in den Begrenzungsring 19 der Kontaktstoff 9 eingeführt.The start of the device from the cold to Stand is carried out by means of a radiator 7 placed on the fixed insert 5, the surfaces of the radiators 7 being in contact with the insert and the electrode 10 by means of carbon paste, while the electrode 11 is in contact with the insert 5. During the start-up period, nitrogen is introduced into the chamber 3, which protects the carbon paste against oxidation. After the feed 5 has melted, the contact substance 9 is introduced into the limiting ring 19.

Fig. 11 stellt drei quaderförmige, frei im Metall 5 innerhalb des Begrenzungsrings 19 schwimmende Heizkörper 7 dar. Die Heizkörper 7 sind mit einer Metallschicht 8 bedeckt, welche von dem Metall 5 durch eine Schicht von geschmolzenem Salz 9 getrennt ist, wobei die Schicht des geschmolzenen Salzes 9 bis unterhalb der oberen Ränder der Heizkörper 7 reicht. Unter der Einwirkung des zwischen den Elektroden 10 und 11 bestehenden Potentialunterschieds fließt der elektrische Strom von der Elektrode 10 durch das Metall 8, parallel durch das Salz 9 und die Heizkörper 7 zum Metall 5 und schließlich zur Elektrode 11. Das Metall 8 ist eine Aluminiumlegierung, und das Metall 5 eine Aluminiumbronze. Die Elektroden 10 und 11 bestehen aus Graphit und sind mit einer Schicht aus aus der Gasphase ausgetragenem Siliziumkarbid bedeckt. Das Salz 9 ist eine Mischung von Natriumkarbonat und -chlorid. Die Heizkörper 7 sind aus nitridiertem Siliziumkarbid, und der Begrenzungsring 19 ist aus Schamottestoff ausgeführt.Fig. 11 shows three cuboid radiators 7 floating freely in the metal 5 within the limiting ring 19. The radiators 7 are covered with a metal layer 8 which is separated from the metal 5 by a layer of molten salt 9, the layer of the molten salt Salt 9 extends below the upper edges of the radiators 7. Under the influence of the potential difference between the electrodes 10 and 11, the electrical current flows from the electrode 10 through the metal 8, in parallel through the salt 9 and the heating elements 7 to the metal 5 and finally to the electrode 11. The metal 8 is an aluminum alloy, and the metal 5 is an aluminum bronze. The electrodes 10 and 11 consist of graphite and are covered with a layer of silicon carbide discharged from the gas phase. Salt 9 is a mixture of sodium carbonate and chloride. The radiators 7 are made of nitrided silicon carbide, and the limiting ring 19 is made of fireclay material.

Fig. 12 zeigt einen kegelrohrförmigen Heizkörper 7, der in dem Bad 5, nämlich hier dem geschmolzenen Salz, mittels des Halters 20 und des Seils 21 an dem Tragwerk der Einrichtung derart beweglich aufgehängt ist, daß der Heizkörper 7 stets eine unveränderliche, von dem Badstand des Salzes unabhängige Eintauchtiefe aufweist.Fig. 12 shows a conical tubular heater 7, which is suspended in the bath 5, namely here the molten salt, by means of the holder 20 and the rope 21 on the supporting structure of the device such that the heater 7 is always a constant, from the bath level of the salt has an independent immersion depth.

Die an die Stromzuleitung 12 angeschlossene Elektrode 10 steht in unmittelbarem Kontakt mit einer Fläche des Heizkörpers 7. Der Kegelteil der Elektrode 10 erfüllt gleichzeitig die Funktion des Kontaktstoffs. Die Außenfläche des Heizkörpers 7 ist mit einer dünnen Schicht eines Stoffes 15 bedeckt.The electrode 10 connected to the power supply line 12 is in direct contact with a surface of the radiator 7. The conical part of the electrode 10 simultaneously fulfills the function of the contact substance. The outer surface of the radiator 7 is covered with a thin layer of a fabric 15.

Unter der Einwirkung des zwischen den Elektroden 10 und 11 bestehenden Potentialunterschieds fließt der elektrische Strom von der Elektrode 10 parallel durch den Heizkörper 7 und die Elektrode 10 zum Salz 5, und schließlich zur Elektrode 11. Das Salz 5 ist eine Mischung von Barium- und Kalziumchlorid. Der Stoff 15 besteht aus einem aus der Gasphase aufgetragenen Siliziumkarbid. Die Elektrode 10 ist aus reaktivweise gesintertem Siliziumkarbid ausgeführt. Die Elektrode 11 besteht aus Graphit mit einer aus der Gasphase aufgetragenen dünnen Schicht aus Siliziumkarbid. Der Halter 20 und das Seil 21 sind aus Legierungsstahl, und der Heizkörper 7 aus nitridiertem Siliziumkarbid gefertigt.Under the influence of the potential difference between the electrodes 10 and 11, the electric current flows from the electrode 10 in parallel through the heating element 7 and the electrode 10 to the salt 5, and finally to the electrode 11. The salt 5 is a mixture of barium and calcium chloride . The substance 15 consists of a silicon carbide applied from the gas phase. The electrode 10 is made of reactive sintered silicon carbide. The electrode 11 consists of graphite with a thin layer of silicon carbide applied from the gas phase. The holder 20 and the rope 21 are made of alloy steel, and the heating element 7 is made of nitrided silicon carbide.

Fig. 13 zeigt einen gefäßförmigen, in eine wäßrige Lösung 5 von Schwefelsäure eingetauchten, unter einem Schwimmer 6 aufgehängten Heizkörper 7, wobei das Innere des Heizkörpers 7 mit Metall 8 aufgefüllt ist. Der Heizkörper 7 ist an seiner Außenseite mit einer dünnen Schicht eines Stoffs 15 bedeckt. Das Metall 8 ist Woodmetall. Der Schwimmer 6 besteht aus Polyäthylen, die Elektrode 10 aus Graphit, die Elektrode 11 aus säurebeständigem Stahl und der Schwimmer 22 aus Graphit. Der Heizkörper 7 ist aus gesintertem, auf Graphit basierendem Werkstoff ausgeführt. Die Schicht 15 besteht aus aus der Gasphase ausgetragenem Siliziumkarbid.13 shows a vessel-shaped radiator 7 immersed in an aqueous solution 5 of sulfuric acid and suspended under a float 6, the interior of the radiator 7 being filled with metal 8. The heater 7 is covered on the outside with a thin layer of a fabric 15. The metal 8 is wood metal. The float 6 consists of polyethylene, the electrode 10 made of graphite, the electrode 11 made of acid-resistant steel and the float 22 made of graphite. The heater 7 is made of sintered, graphite-based material. The layer 15 consists of silicon carbide discharged from the gas phase.

Fig. 14 zeigt einen Heizkörper 7 in Form eines Doppeigefäßes, das zum Teil in das Metall 5 eingetaucht und zum Teil mit Metall 8 gefüllt ist und wobei die Wand 23 das Bad 5 in zwei voneinander isolierte Teile trennt.14 shows a heating element 7 in the form of a double egg vessel, which is partly immersed in the metal 5 and partly filled with metal 8, and the wall 23 separates the bath 5 into two parts which are insulated from one another.

Unter der Einwirkung des zwischen der an die Stromzuleitung 12 angeschlossenen Elektrode 10 und der an die Stromzuleitung 13 angeschlossenen Elektrode 11 bestehenden Potentialunterschieds fließt elektrischer Strom von der Elektrode 10 durch das Metall 5, die Wände des Heizkörpers 7 und das Metall 5 zur Elektrode 11. Der Heizkörper 7 besteht aus einem gesinterten, auf Zirkoniumdioxid basierenden Werkstoff.Under the action of the potential difference existing between the electrode 10 connected to the power supply line 12 and the electrode 11 connected to the power supply line 13, electrical current flows from the electrode 10 through the metal 5, the walls of the radiator 7 and the metal 5 to the electrode 11. The Radiator 7 consists of a sintered material based on zirconium dioxide.

Dabei kann z. B. der Werkstoff des linken Gefäßes andere physikalische und chemische Eigenschaften aufweisen als der des rechten Gefäßes und zwar in Abhängigkeit von der unterschiedlichen Höhe der beiden Gefäße. Die Elektroden 10 und 11 bestehen aus Graphit. Die Wand 23 ist aus einem auf Korund basierenden Werkstoff gefertigt.Here, for. B. the material of the left vessel have different physical and chemical properties than that of the right vessel, depending on the different height of the two vessels. The electrodes 10 and 11 are made of graphite. The wall 23 is made of a material based on corundum.

Claims (22)

1. An electrical device for the direct heating of metals and/or salts in the molten state and solutions having at least one resistence heating member (7) in the form of a vessel partially immersed in the bath (5) to be heated and in which a contact material (8, 9) is disposed, in which material there is inserted an electrode (10) by means of which a voltage potential between the contact material, the heating member and the bath is produced in cooperation with at least one counter-electrode (13) acting on the bath (5), characterised in that the heating member (7) comprises at least two permanently connected moulded components, these components consisting of different materials with different physical and/or chemical properties.
2. A device as claimed in claim 1, characterised in that a ring (14) of aluminium silicate is fastened to the upper edge of the vessel-shaped moulded body (Fig. 1 and 6).
3. A device as claimed in claim 1, characterised in that the material of one of the moulded components (17) has a lower electrical conductivity than that of the other moulded component (16) (Fig. 7).
4. A device as claimed in one of claims 1 to 3, characterised in that the electrically active surface of the heating member (7) is covered at least partially with a layer of a material (15) which is resistant to the chemical action of the charging material and/or the contact material (8, 9).
5. A device as claimed in one of claim 1 to 4, characterised in that the heating member (7) is saturated with substance reducing the porosity of its material.
6. An electrical device for the direct heating of metals and/or salts in the molten state and solutions having at least one resistance heating member (7) in the form of a vessel partially im- merset in the bath (5) to be heated and in which a contact material (8, 9) is disposed, in which material there is inserted an electrode (10) by means of which a voltage potential between the contact material, the heating member and the bath is produced in cooperation with at least one counter-electrode (13) acting on the bath (5), characterised in that the heating member consists of two vessels, one vessel being disposed within the other and the space between the vessels and the interior of the inner vessel being partially filled with contact material (8, 9), and in that the vessels are disposed in a row between the electrode (10) inserted in the contact material (8) of the inner vessel and the counter-electrode (13).
7. An electrical device for the direct heating of metals and/or salts in the molten state and solutions having at least one resistance heating member (7) in the form of a vessel partially immersed in the bath (5) to be heated and in which a contact material (8, 9) is disposed, in which material there is inserted an electrode (10) by means of which a voltage potential between the contact material, the heating member and the bath is produced in cooperation with at least one counter-electrode (11), characterised in that a heating body (7) is provided in the form of a double vessel which forms a series arrangement of two individual heating members and is immersed in the bath (5) of be heated and on both sides of a wall (23) divides the bath (5) to be heated into two portions insulated from one another, the two electrodes (10, 11) being disposed on one and the other side of the dividing wall (23) (Fig. 14).
8. An electrical device for the direct heating of metals and/or salts in the molten state and solutions having at least one resistance heating member (7) in the form of a vessel partially immersed in the bath (5) to be heated and in which a contact material (8, 9) is disposed, in which material there is inserted an electrode (10) by means of which a voltage potential between the contact material, the heating member and the bath is produced in cooperation with at least one counter-electrode (11) acting on the bath (5), characterised in that the electrically active surface of the heating member (7) is at least partially covered with a layer of a material (15) which is resistant to the chemical action of the charging material and/or of the contact material (8, 9) (Fig. 13).
9. An electrical device as claimed in the preceding claims, characterised in that at least two contact materials (8, 9) are inserted into the vessel-shaped heating member (7).
10. An electrical device for the direct heating of metals and/or salts in the molten state and solutions having at least one resistance heating member (7) in the form of a dividing wall partially immersed in the bath (5) to be heated, which wall is associated with at least one electrode (10) by means of which a voltage potential is produced between the heating member and the bath, characterised in that the dividing wall (7) is tubular in shape and the electrode (10) disposed in the interior of the tube fulfils the function of a contact material (Fig. 12).
11. A device as claimed in claim 10, characterised in that the electrically active surface of the heating member (7) is at least partially covered with a material (15) which is resistant to the chemical action of the charging material and/or of the contact material.
12. An electrical device for the direct heating of metals and/or salts in the molten state and solutions having at least one resistance heating member (7) partically immersed in the bath (5) to be heated, a contact material (8, 9) cooperating with this resistance heating member (7) in which at least one electrode (10) is inserted, by means of which a voltage potential between the contact material, the heating member and the bath is produced in cooperation with a counter-electrode (13) acting in the bath (5), characterised in that the heating member (7) takes the form of bodies disposed inside a stop ring (19), the bodies being covered with a layer of a contact material (9) having a thickness which is smaller than the thickness of the material of the bath (5) to be heated and the material of the heating member (7) (Fig. 10 and 11).
13. A device as claimed in claim 12, characterised in that the layer of contact material (8) which covers the bodies forming the heating member (7) is separated from the bath (5) by a layer of a further contact material (9) in such a way that the bodies of the heating member (7) are connected both in series and in parallel (Fig. 11).
14. A device as claimed in one of the preceding claims, characterised in that the heating member (7) floats freely in the bath (5) to be heated.
15. A device as claimed in one of the preceding claims, characterised in that the heating member (7) floats immersed in a forced manner in the bath (5) to be heated, the immersion being caused by a weigth (18).
16. A device as claimed in one of the preceding claims, characterised in that the weight (18) of the heating member (7) is formed for the introduction of a protective gas into the interior of the heating member (7).
17. A device as claimed in one of the preceding claims, characterised in that the weight (18) of the heating member (7) is provided with an auxiliary resistance heating member which is disposed in the direct vicinity of the area of the heating member (7) projecting from the bath (5) and is switched into the circuit of the heating member (7).
18. A device as claimed in one of the preceding claims, characterised in that the heating member (7) is fastened in a movably suspended manner in such a way that the heating member (7) has a constant depth of immersion even if the height of the bath (5) to be heated is modified.
19. A device as claimed in one of the preceding claims, characterised in that the heating member (7) immersed partially in the bath (5) to be heated is rigidly fastened to a support frame.
20. A device as claimed in one of the preceding claims, characterised in that the supply voltage of the heating member (7) is adjustable and in that the bath (5) to be heated is earthed.
21. A device as claimed in one of claims 1 to 20, characterised in that starting from the cold condition in which the charging material is in the solid state is carried out by an additional heating member (7) which operates until the first batch or charge of the charging material (5) has melted.
22. A device as claimed in one of claim 1 to 20, characterised in that starting from the cold condition in which the charging material (5) is in its solid state is carried out by a heating member (7) placed on the charging material, the surfaces of the heating member (7) lying on the charging material and the electrodes (10) lying above additional contact materials.
EP80102887A 1979-05-23 1980-05-23 Electrically operated device for the heating of metals and/or salts in the molten state, and of solutions Expired EP0019876B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80102887T ATE16550T1 (en) 1979-05-23 1980-05-23 ELECTRICALLY OPERATED DEVICE FOR HEATING METALS AND/OR MOLTEN SALTS AND SOLUTIONS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PL215839 1979-05-23
PL1979215839A PL124892B1 (en) 1979-05-23 1979-05-23 Electric apparatus for direct heating of molten metals and/or salts and solutions,especially water solutions and glasses

Publications (2)

Publication Number Publication Date
EP0019876A1 EP0019876A1 (en) 1980-12-10
EP0019876B1 true EP0019876B1 (en) 1985-11-13

Family

ID=19996455

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80102887A Expired EP0019876B1 (en) 1979-05-23 1980-05-23 Electrically operated device for the heating of metals and/or salts in the molten state, and of solutions

Country Status (11)

Country Link
EP (1) EP0019876B1 (en)
JP (1) JPS55159588A (en)
AT (1) ATE16550T1 (en)
CS (1) CS228131B2 (en)
DD (1) DD150980A5 (en)
DE (1) DE3071226D1 (en)
HU (1) HU181716B (en)
IN (1) IN150776B (en)
PL (1) PL124892B1 (en)
SU (1) SU1170975A3 (en)
YU (1) YU137180A (en)

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE313058C (en) *
CH88060A (en) * 1919-09-12 1921-02-01 Guettinger Heinrich Electric melting furnace with resistance heating for metals.
US1971025A (en) * 1931-02-16 1934-08-21 Bornand Emilien Metal heater
DE620835C (en) * 1932-06-21 1935-10-28 Aeg Electric heater for salt baths
PL81320B1 (en) * 1970-03-27 1975-08-30
FR2226063A7 (en) * 1973-04-10 1974-11-08 Zaklady Cynkowe Szopienice Electrical resistance furnace - for melting and keeping molten non ferrous metals, partic zinc (alloys)
US4158743A (en) * 1976-03-01 1979-06-19 Biuro Projektow Pyrzemyslu Metali Niezelaznych "Bipromet" Electric resistance furnace

Also Published As

Publication number Publication date
EP0019876A1 (en) 1980-12-10
DE3071226D1 (en) 1985-12-19
PL124892B1 (en) 1983-02-28
ATE16550T1 (en) 1985-11-15
CS228131B2 (en) 1984-05-14
IN150776B (en) 1982-12-11
PL215839A1 (en) 1981-01-02
HU181716B (en) 1983-11-28
JPS55159588A (en) 1980-12-11
DD150980A5 (en) 1981-09-23
SU1170975A3 (en) 1985-07-30
YU137180A (en) 1982-08-31

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