EP0019876B1 - Elektrisch betriebene Einrichtung zur Erhitzung von Metallen und/oder Salzen im geschmolzenen Zustand sowie von Lösungen - Google Patents

Elektrisch betriebene Einrichtung zur Erhitzung von Metallen und/oder Salzen im geschmolzenen Zustand sowie von Lösungen 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
Authority
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
Application number
EP80102887A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0019876A1 (de
Inventor
Felicjan Biolik
Adam Lukasik
Zygmunt Morys
Stanislaw Walawender
Szczepan Galazka
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.)
Biuro Projektow Przemyslu Metali Niezelaznych "Bipromet"
Original Assignee
Biuro Projektow Przemyslu Metali Niezelaznych "Bipromet"
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Biuro Projektow Przemyslu Metali Niezelaznych "Bipromet" filed Critical Biuro Projektow Przemyslu Metali Niezelaznych "Bipromet"
Priority to AT80102887T priority Critical patent/ATE16550T1/de
Publication of EP0019876A1 publication Critical patent/EP0019876A1/de
Application granted granted Critical
Publication of EP0019876B1 publication Critical patent/EP0019876B1/de
Expired legal-status Critical Current

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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.

Landscapes

  • Resistance Heating (AREA)
  • Furnace Details (AREA)
  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
  • Air Bags (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Control Of Resistance Heating (AREA)
EP80102887A 1979-05-23 1980-05-23 Elektrisch betriebene Einrichtung zur Erhitzung von Metallen und/oder Salzen im geschmolzenen Zustand sowie von Lösungen Expired EP0019876B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80102887T ATE16550T1 (de) 1979-05-23 1980-05-23 Elektrisch betriebene einrichtung zur erhitzung von metallen und/oder salzen im geschmolzenen zustand sowie von loesungen.

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 (de) 1980-12-10
EP0019876B1 true EP0019876B1 (de) 1985-11-13

Family

ID=19996455

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80102887A Expired EP0019876B1 (de) 1979-05-23 1980-05-23 Elektrisch betriebene Einrichtung zur Erhitzung von Metallen und/oder Salzen im geschmolzenen Zustand sowie von Lösungen

Country Status (11)

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

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE313058C (cs) *
CH88060A (de) * 1919-09-12 1921-02-01 Guettinger Heinrich Elektrischer Schmelzofen mit Widerstandsheizung für Metalle.
US1971025A (en) * 1931-02-16 1934-08-21 Bornand Emilien Metal heater
DE620835C (de) * 1932-06-21 1935-10-28 Aeg Elektrischer Anheizkoerper fuer Salzbadeoefen
PL81320B1 (cs) * 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
HU181716B (en) 1983-11-28
EP0019876A1 (de) 1980-12-10
IN150776B (cs) 1982-12-11
DD150980A5 (de) 1981-09-23
SU1170975A3 (ru) 1985-07-30
PL215839A1 (cs) 1981-01-02
JPS55159588A (en) 1980-12-11
CS228131B2 (en) 1984-05-14
ATE16550T1 (de) 1985-11-15
PL124892B1 (en) 1983-02-28
YU137180A (en) 1982-08-31
DE3071226D1 (en) 1985-12-19

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