EP0025417A1 - Crust-breaking device for an electrolytic furnace - Google Patents

Crust-breaking device for an electrolytic furnace Download PDF

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Publication number
EP0025417A1
EP0025417A1 EP80810284A EP80810284A EP0025417A1 EP 0025417 A1 EP0025417 A1 EP 0025417A1 EP 80810284 A EP80810284 A EP 80810284A EP 80810284 A EP80810284 A EP 80810284A EP 0025417 A1 EP0025417 A1 EP 0025417A1
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EP
European Patent Office
Prior art keywords
chisel
crust
recess
edge
underside
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Granted
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EP80810284A
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German (de)
French (fr)
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EP0025417B1 (en
Inventor
Thomas Haggenmacher
Edwin Gut
Hans Friedli
Gottfried Maugweiler
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Alcan Holdings Switzerland AG
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Alusuisse Holdings AG
Schweizerische Aluminium AG
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Priority to AT80810284T priority Critical patent/ATE1824T1/en
Publication of EP0025417A1 publication Critical patent/EP0025417A1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D17/00—Details of, or accessories for, portable power-driven percussive tools
    • B25D17/02—Percussive tool bits
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
    • C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
    • C25C3/14—Devices for feeding or crust breaking

Definitions

  • the present invention relates to a chisel for a wrapping device for breaking the solidified crust of an electrolytic cell, in particular for the production of A lu- minium.
  • the cell is usually operated periodically in normal operation, even if there is no anode effect.
  • the bath crust has to be hammered in and the alumina concentration increased by adding new aluminum oxide, which corresponds to cell operation.
  • the inventors have therefore set themselves the task of creating a chisel shape for an impact device for breaking the solidified crust of an electrolysis furnace, in which the force required for impact is considerably reduced.
  • the object is achieved according to the invention in that at least parts of the edge area of the chisel underside protrude beyond the remaining areas and are designed as punched edges, and in that the chisel underside has no outwardly inclined surfaces which cause outward side forces when the crust is pierced.
  • this acts like a punching or shearing tool when the electrolyte crust is hammered in.
  • the lower expenditure of force for perforating the crust reduces the expenditure of energy and on the other hand allows the use of less massive impact devices, which also makes it possible to keep the investments lower.
  • the chisels are made of common material, preferably St 45 - 50, a hard and weldable steel poses. Chisels with rectangles elongated in cross-section, e.g. 150 x 40 mm, are particularly favorable for the central, transverse or point control, which is increasingly used for environmental protection reasons, because when converting existing furnaces, the anode distance in the longitudinal axis of the furnace (central control) or transverse axis of the furnace (Cross control) does not have to be changed or only insignificantly.
  • conical, truncated cone or dome-shaped recesses are preferred for chisels that are round in cross section, and wedge-shaped recesses for chisels that are rectangular in cross section.
  • the impact device which in principle consists of a pressure cylinder, piston rod and chisel, is attached directly or indirectly to the cell structure or is part of an operating vehicle or furnace manipulator.
  • a cylindrical chisel 10 is shown which instead of a flat lower end face a conical Has shaped recess 12.
  • the outer surface of this cone-shaped recess 12 and the outer surface of the cylinder 10 mild a circular cut surface visible from below, which represents the punched surface.
  • the surface lines of the cone-shaped recess 12 form an angle ⁇ with the horizontal, which is preferably in the range from 15 to 450. At smaller angles, the effect of the chisel used as a punching tool decreases, larger angles than 45 ° are increasingly uninteresting for economic and mechanical reasons.
  • the outer surface 14 of the truncated cone acts in the same way as the outer surface 12 of the cone of FIG force directed downwards only when the chisel has already been pressed a little into the crust.
  • a chisel 18 with a rectangular cross section is shown, which has a wedge-shaped recess 20 instead of a horizontal, flat end face.
  • the same criteria apply to the choice of the angle of inclination ⁇ of this fishtail shape as in the previous figures.
  • the recessed triangular part in the sectional plane of FIG. 5 can also be trapezoidal in a variant not shown, similar to that in FIG. 3.
  • the recess does not begin at the circumference of the chisel, but is slightly indented, as a result of which a horizontal surface 26 is formed in the edge region.
  • the recess 28 follows on the inside of this horizontal surface, preferably with the values given above for ⁇ . In this embodiment of the chisel, more force has to be applied when the crust is pressed in in the initial phase; however, the wear on chisel material is less.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Debarking, Splitting, And Disintegration Of Timber (AREA)
  • Working Measures On Existing Buildindgs (AREA)
  • Crushing And Pulverization Processes (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
  • Materials For Medical Uses (AREA)
  • Organic Insulating Materials (AREA)
  • Apparatus Associated With Microorganisms And Enzymes (AREA)
  • Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Discharge Heating (AREA)
  • Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Conductive Materials (AREA)
  • Shovels (AREA)
  • Crushing And Grinding (AREA)
  • Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)

Abstract

A chisel for a crust breaking facility for breaking through the solidified crust of electrolyte on an electrolytic cell, in particular a cell for producing aluminum, is such that at least a part of the edge region on the bottom face of the chisel projects out beyond the other regions and is in the form of cutting edges. The bottom face of the chisel features no faces which are inclined outwards and would create outward directed forces as the chisel is forced through the crust. The chisel of the invention allows energy and investment costs to be reduced.

Description

Die vorliegende Erfindung bezieht sich auf einen Meissel für eine Einschlagvorrichtung zum Brechen der erstarrten Kruste eines Elektrolyseofens, insbesondere zur Herstellung von Alu- minium.The present invention relates to a chisel for a wrapping device for breaking the solidified crust of an electrolytic cell, in particular for the production of A lu- minium.

Für die Gewinnung von Aluminium durch Elektrolyse von Aluminiumoxid wird dieses in einer Fluoridschmelze gelöst, die zum grössten Teil aus Kryolith besteht. Das kathodisch abgeschiedene Aluminium sammelt sich unter der Fluoridschmelze auf dem Kohleboden der Zelle, wobei die Oberfläche des flüssigen Aluminiums die Kathode bildet. In die Schmelze tauchen von oben Anoden ein, die bei konventionnellen Verfahren aus amorphem Kohlenstoff bestehen. An den Kohleanoden entsteht durch die elektrolytische Zersetzung des Aluminiumoxids Sauerstoff, der sich mit dem Kohlenstoff der Anoden zu C02 und CO verbindet. Die Elektrolyse findet in einem Temperaturbereich von etwa 940 - 970° C statt.For the production of aluminum by electrolysis of aluminum oxide, this is dissolved in a fluoride melt, which largely consists of cryolite. The cathodically deposited aluminum collects under the fluoride melt on the carbon bottom of the cell, the surface of the liquid aluminum forming the cathode. Anodes, which consist of amorphous carbon in conventional processes, are immersed in the melt. At the carbon anodes, the electrolytic decomposition of the aluminum oxide produces oxygen, which combines with the carbon of the anodes to form CO 2 and CO. The electrolysis takes place in a temperature range of approximately 940 - 970 ° C.

Im Laufe der Elektrolyse verarmt der Elektrolyt an Aluminiumoxid. Bei einer unteren Konzentration von l - 2 Gew.-% Aluminiumoxid im Elektrolyten kommt es zum Anodeneffekt, der sich in einer Spannungserhöhung von beispielsweise 4 - 4,5 V auf 30 V und darüber auswirkt. Spätestens dann muss die Kruste eingeschlagen und die Aluminiumoxidkonzentration durch Zugabe von neuem Aluminiumoxid (Tonerde) angehoben werden.In the course of electrolysis, the electrolyte becomes poor in aluminum oxide. At a lower concentration of 1-2% by weight of aluminum oxide in the electrolyte, there is an anode effect, which results in a voltage increase of, for example, 4-4.5 V to 30 V and above. At the latest then the crust must be hammered in and the aluminum oxide concentration increased by adding new aluminum oxide (alumina).

Die Zelle wird im normalen Betrieb üblicherweise periodisch bedient, auch wenn kein Anodeneffekt auftritt. Ausserdem muss bei jedem Anodeneffekt die Badkruste eingeschlagen und die Tonerdekonzentration durch Zugabe von neuem Aluminiumoxid angehoben werden, was einer Zellenbedienung entspricht.The cell is usually operated periodically in normal operation, even if there is no anode effect. In addition, with each anode effect, the bath crust has to be hammered in and the alumina concentration increased by adding new aluminum oxide, which corresponds to cell operation.

Zur Zellenbedienung ist über lange Jahre die Kruste aus erstarrter Schmelze zwischen den Anoden und dem Seitenbord der Elektrolysezelle eingeschlagen und anschliessend neues Aluminiumoxid zugegeben worden. Diese heute noch weitgehend angewandte Praxis stösst auf zunehmende Kritik wegen Verschmutzung der Luft in der Elektrolysehalle und der äusseren Atmosphäre. Die Forderung nach Kapselung der Elektrolyseöfen und die Behandlung der Abgase ist in den letzten Jahren zunehmend zur zwingenden Notwendigkeit geworden. Eine maximale Zurückhaltung der Elektrolysegase durch Kapselung kann jedoch nicht gewährleistet werden, wenn eine klassische Längsseitenbedienung zwischen den Anoden und dem Seitenbord der Oefen erfolgt.The crust of solidified melt has been hammered in between the anodes and the side board of the electrolytic cell for cell operation and then new aluminum oxide has been added. This practice, which is still widely used today, is met with increasing criticism for pollution of the air in the electrolysis hall and the outside atmosphere. The demand for encapsulation of the electrolysis furnaces and the treatment of the exhaust gases has become an imperative in recent years. However, maximum containment of the electrolysis gases by encapsulation cannot be guaranteed if classic long side operation takes place between the anodes and the side board of the furnaces.

In neuerer Zeit sind deshalb die Aluminiumhersteller immer mehr zur Bedienung in der Ofenlängsachse übergegangen. Nachdem Einschlagen der Kruste erfolgt die Tonerdezugabe entweder lokal und kontinuierlich nach dem "Point-Feeder"-Prinzip oder nichtkontinuierlich über die ganze Ofenlängsachse verteilt. In beiden Fällen ist auf der Elektrolysezelle ein Vorratsbunker für die Tonerde angeordnet. Entsprechendes gilt für die von der Anmelderin in jüngerer Zeit vorgeschlagene Querbedienung der Elektrolyseöfen ( DE-Patent Nr. 27 31 908).In recent times, aluminum manufacturers have therefore increasingly switched to operating in the longitudinal axis of the furnace. After turning of the crust occurs, the alumina addition either locally and continuously according to the "point-Feeder" - principle or distributed non-continuously throughout the oven longitudinal axis. In both cases, a storage hopper for the alumina is arranged on the electrolysis cell. The same applies to the transverse operation of the electrolysis furnaces recently proposed by the applicant (DE Patent No. 27 31 908).

Für das Einschlagen des erstarrten Flusses werden in bekannten Vorrichtungen im Querschnitt rechteckige oder runde Meissel eingesetzt.In known devices, rectangular or round chisels with a cross-section are used to strike the solidified flow.

Der untere, beim Einschlagen mit der Kruste unmittelbar in Eingriff stehende Bereich des Meissels ist bei diesen bekannten Vorrichtungen folgendermassen ausgebildet:

  • - Ebene, zu den Seitenflächen der Meissel vertikal angeordnete Stirnfläche (CH-PS 520 778). Diese Ausführungsform des Meissels kann als Normalfall bezeichnet werden.
  • - Runder Meissel mit einer kegelförmigen Spitze (DE-PS 2 135 485)
  • - Kegelstumpfförmige Einengung eines runden Meissels (US-PS 3 371 026).
The lower area of the chisel, which directly engages the crust when hammered in, is designed as follows in these known devices:
  • - Level, face arranged vertically to the side surfaces of the chisel (CH-PS 520 778). This embodiment of the chisel can be called the normal case.
  • - Round chisel with a conical tip (DE-PS 2 135 485)
  • - Truncated cone-shaped constriction of a round chisel (US Pat. No. 3,371,026).

Ebene untere Stirnflächen von Meisseln weisen jedoch den Nachteil auf, dass die verhältnismässig harte und dicke Elektrolytkruste gleichzeitig über die ganze Querschnittsfläche eingedrückt werden muss. Beim Einsatz von sich im untersten Bereich verjüngenden Meisseln wird wohl die anzuwendende Vertikalkraft kleiner, es sind jedoch infolge der Keilwirkung der Schrägseiten noch beachtliche, seitwärts gerichtete Kräfte zu überwinden. Dies erhöht nicht nur den Energieaufwand, sondern auch die Investitionskosten in beträchtlichem Masse.Flat lower end faces of chisels, however, have the disadvantage that the relatively hard and thick electrolyte crust has to be pressed in simultaneously over the entire cross-sectional area. When using chisels tapering in the lowest area, the vertical force to be applied is likely to be smaller, however, due to the wedge effect of the oblique sides, considerable forces directed sideways have to be overcome. This not only increases the energy consumption, but also the investment costs to a considerable extent.

Die Erfinder haben sich deshalb die Aufgabe gestellt, eine Meisselform für eine Einschlagvorrichtung zum Brechen der erstarrten Kruste eines Elektrolyseofens zu schaffen, bei welcher der für das Einschlagen erforderliche Kraftaufwand erheblich vermindert wird.The inventors have therefore set themselves the task of creating a chisel shape for an impact device for breaking the solidified crust of an electrolysis furnace, in which the force required for impact is considerably reduced.

Die Aufgabe wird erfindungsgemäss dadurch gelöst, dass mindestens Teile des Randbereichs der Meisselunterseite deren übrige Bereiche überragen und als Stanzkanten ausgebildet sind, und dass die Meisselunterseite keine nach aussen geneigte, beim Durchstossen der Kruste nach aussen gerichtete Seitenkräfte bewirkende Flächen aufweist.The object is achieved according to the invention in that at least parts of the edge area of the chisel underside protrude beyond the remaining areas and are designed as punched edges, and in that the chisel underside has no outwardly inclined surfaces which cause outward side forces when the crust is pierced.

Beim Einsatz eines Meissels mit erfindungsgemäss ausgesparter Unterseite wirkt dieser beim Einschlagen der Elektrolytkruste wie ein Stanz- bzw. Abscherwerkzeug. Der geringere Kraftaufwand zum Durchlöchern der Kruste vermindert einerseits den Energieaufwand und erlaubt andererseits, mit weniger massiv gebauten Schlagvorrichtungen auszukommen, was auch die Investitionen niedriger zu halten ermöglicht.When using a chisel with a recessed underside according to the invention, this acts like a punching or shearing tool when the electrolyte crust is hammered in. The lower expenditure of force for perforating the crust on the one hand reduces the expenditure of energy and on the other hand allows the use of less massive impact devices, which also makes it possible to keep the investments lower.

Die Meissel werden aus üblichem Material, vorzugweise aus St 45 - 50, einem harten und schweissbaren Stahl, hergestellt. Für die aus den aus Umweltschützgründen zunehmend häufiger angewandte Mittel-, Quer- oder Punktbedienung sind Meissel mit im Querschnitt länglichen Rechtecke, z.B. 150 x 40 mm, besonders günstig, weil beim Umrüsten von bestehenden Oefen der Anodenabstand in der Ofenlängsachse (Mittelbedienung) bzw. Ofenquerachse (Querbedienung) nicht oder nur unwesentlich verändert werden muss.The chisels are made of common material, preferably St 45 - 50, a hard and weldable steel poses. Chisels with rectangles elongated in cross-section, e.g. 150 x 40 mm, are particularly favorable for the central, transverse or point control, which is increasingly used for environmental protection reasons, because when converting existing furnaces, the anode distance in the longitudinal axis of the furnace (central control) or transverse axis of the furnace (Cross control) does not have to be changed or only insignificantly.

Aus fertigungstechnischen Gründen sind bei im Querschnitt runden Meisseln kegel-,-kegelstumpf- oder kalottenförmige Aussparungen, bei im Querschnitt rechteckigen-Meisseln keilförmige Aussparungen bevorzugt.For manufacturing reasons, conical, truncated cone or dome-shaped recesses are preferred for chisels that are round in cross section, and wedge-shaped recesses for chisels that are rectangular in cross section.

Die Einschlagvorrichtung, welche im Prinzip aus Druckzylinder, Kolbenstange und Meissel besteht, ist direkt oder indirekt am Zellenaufbau befestigt oder Bestandteil eines Bedienungsfahrzeuges bzw. Ofenmanipulators.The impact device, which in principle consists of a pressure cylinder, piston rod and chisel, is attached directly or indirectly to the cell structure or is part of an operating vehicle or furnace manipulator.

Beispiele von Ausführungsformen der Erfindung werden anhand der Zeichnung schematisch dargestellt. Es zeigen:

  • - Fig. 1 und 2 einen Glockenmeissel mit kegelförmiger Aussparung, Ansicht bzw. von unten
  • - Fig. 3 und 4 einen Glockenmeissel mit kegelstumpfförmiger Aussparung, Ansicht bzw. von unten
  • - Fig. 5 und 6 einen fischschwanzförmig ausgebildeten Meissel, Ansicht bzw. von unten
  • - Fig. 7 und 8 Varianten der Ausbildung des Randbereichs bei A von Fig. 1, 3 und 5.
Examples of embodiments of the invention are shown schematically with the aid of the drawing. Show it:
  • - F ig. 1 and 2 a bell chisel with a conical recess, view or from below
  • - F ig. 3 and 4 a bell chisel with a frustoconical recess, view or from below
  • - Fig. 5 and 6 a fishtail-shaped chisel, view and from below
  • 7 and 8 variants of the formation of the edge region at A of FIGS. 1, 3 and 5.

In den Fig. 1 und 2 wird ein zylinderförmiger Meissel 10 dargestellt, der statt einer ebenen unteren Stirnseite eine kegel-Eörmige Aussparung 12 aufweist. Die Mantelfläche dieser kegel-Eörmigen Aussparung 12 und die Mantelfläche des Zylinders 10 milden eine von unten sichtbare kreisförmige Schnittfläche, welche die Stanzfläche darstellt. Die Mantellinien der kegel-Eörmigen Aussparung 12 bilden mit der Horizontalen einen Winkel α, welcher vorzugsweise im Bereich von 15 - 450 liegt. Bei kleineren Winkeln nimmt die Wirkung des als Stanzwerkzeug eingesetzten Meissels zunehmend ab, grössere Winkel als 45° sind aus wirtschaftlichen und mechanischen Gründen zunehmend uninteressanter.1 and 2, a cylindrical chisel 10 is shown which instead of a flat lower end face a conical Has shaped recess 12. The outer surface of this cone-shaped recess 12 and the outer surface of the cylinder 10 mild a circular cut surface visible from below, which represents the punched surface. The surface lines of the cone-shaped recess 12 form an angle α with the horizontal, which is preferably in the range from 15 to 450. At smaller angles, the effect of the chisel used as a punching tool decreases, larger angles than 45 ° are increasingly uninteresting for economic and mechanical reasons.

Beim Niederdrücken des Meissels 10 wird aus der erstarrten Kruste des Elektrolyten ein kreisförmiges Loch ausgestanzt. Beim Durchgreifen der Kruste bilden sich keine nach aussen gerichtete Kraftkomponenten aus. Die von der Mantelfläche des Kegels 12 ausgeübten Seitenkräfte sind nach innen gerichtet und wirken deshalb auf denjenigen Teil der Kruste, der durchgestossen werden muss.When the chisel 10 is pressed down, a circular hole is punched out of the solidified crust of the electrolyte. When reaching through the crust, no outward force components form. The lateral forces exerted by the lateral surface of the cone 12 are directed inwards and therefore act on that part of the crust which has to be pierced.

Falls die Aussparung eines zylinderförmig ausgestalteten Meissels 10, wie in den Fig. 3 und 4 dargestellt, kegelstumpfförmig ausgebildet ist, wirkt die Mantelfläche 14 des Kegelstumpfs in gleicher Weise wie die Mantelfläche 12 des Kegels von Fig. 1. Die Horizontalfläche 16 übt ihre ausschliesslich nach unten gerichtete Kraft erst aus, wenn der Meissel schon ein Stück weit in die Kruste hineingedrückt worden ist.If the recess of a cylindrical chisel 10, as shown in FIGS. 3 and 4, is frustoconical, the outer surface 14 of the truncated cone acts in the same way as the outer surface 12 of the cone of FIG force directed downwards only when the chisel has already been pressed a little into the crust.

In den Fig. 5 und 6 ist ein im Querschnitt rechtwinkliger Meissel 18 dargestellt, welcher statt einer horizontalen ebenen Stirnfläche eine keilförmige Aussparung 20 aufweist. Für die Wahl des Neigungswinkels α dieser Fischschwanzform gelten dieselben Kriterien wie in den vorhergehenden Figuren. Der in der Schnittebene von Fig. 5 ausgesparte dreieckige Teil kann nach einer nicht dargestellten Variante auch trapezförmig sein, ähnlich wie in Fig. 3.5 and 6, a chisel 18 with a rectangular cross section is shown, which has a wedge-shaped recess 20 instead of a horizontal, flat end face. The same criteria apply to the choice of the angle of inclination α of this fishtail shape as in the previous figures. The recessed triangular part in the sectional plane of FIG. 5 can also be trapezoidal in a variant not shown, similar to that in FIG. 3.

In Fig. 7 ist eine Ausführungsvariante der Stanzkante in vergrösserter Massstab dargestellt. Die Aussparung, gleichgültig ob sie kegel- oder keilförmig ist, verläuft vorerst in einem steileren Winkel 22 und geht dann in einen flacheren Winkel 24 über. Dies hat den Vorteil, dass der Meissel mit weniger Kraft in die Kruste hineingestanzt werden kann. Für diese Variante ist jedoch nur sehr hartes und verschleissfestes Meisselmaterial geeignet.7 shows a variant of the punched edge on an enlarged scale. The recess, regardless of whether it is conical or wedge-shaped, initially runs at a steeper angle 22 and then merges into a flatter angle 24. This has the advantage that the chisel can be punched into the crust with less force. However, only very hard and wear-resistant chisel material is suitable for this variant.

In Fig. 8 wird eine weitere Ausführungsvariante der Stanzkante des Meissels gezeigt. Die Aussparung beginnt nicht am Umfang des Meissels, sondern ist etwas eingerückt, wodurch im Randbereich eine Horizontalfläche 26 gebildet wird. Auf der Innenseite dieser Horizontalfläche folgt die Aussparung 28, vorzugsweise mit den oben für α angegebenen Werten. Bei dieser Ausführungsform des Meissels muss beim Eindrücken der Kruste in der Anfangsphase mehr Kraft aufgewendet werden; dafür ist jedoch der Verschleiss an Meisselmaterial geringer.8 shows a further embodiment variant of the punching edge of the chisel. The recess does not begin at the circumference of the chisel, but is slightly indented, as a result of which a horizontal surface 26 is formed in the edge region. The recess 28 follows on the inside of this horizontal surface, preferably with the values given above for α. In this embodiment of the chisel, more force has to be applied when the crust is pressed in in the initial phase; however, the wear on chisel material is less.

Es versteht sich von selbst, dass die Vorteile der Erfindung auch mit anderen Formen der Aussparung an der Unterseite des Meissels erreicht werden können, falls keine nach aussen gerichteten Seitenkräfte erzeugt werden.It goes without saying that the advantages of the invention can also be achieved with other forms of the recess on the underside of the chisel if no outward side forces are generated.

Claims (6)

1. Meissel für eine Einschlagvorrichtung zum Brechen der er- f starrten Kruste eines Elektrolyseofens, insbesondere zur Herstellung von Aluminium,
dadurch gekennzeichnet, dass g
mindestens Teile des Randbereichs der Meisselunterseite deren übrige Bereiche überragen und als Stanzkanten ausgebildet sind, und dass die Meisselunterseite keine;nach aussen geneigte, beim Durchstossen der Kruste nach aussengerichtete Seitenkräfte bewirkenden Flächen aufweist.1. chisel for an impact device for breaking the frozen crust of an electrolysis furnace, in particular for the production of aluminum,
characterized in that g
at least parts of the edge area of the bottom of the chisel, the remaining areas of which protrude and are formed as punched edges, and that the underside of the chisel has no surfaces which are inclined outwards and cause lateral forces when the crust is pierced. 2. Meissel nach Anspruch 1, dadurch gekennzeichnet, dass ; dieser zylinderförmig ausgebildet ist und auf der Unter- - : seite eine sich bis in den Randbereich erstreckende kegelförmige, kegelstumpfförmige oder kalottenförmige Aussparung (12, 14, 16) aufweist.2. Chisel according to claim 1, characterized in that; this is cylindrical and has a conical, frustoconical or dome-shaped recess (12, 14, 16) on the underside that extends into the edge region. 3. Meissel nach Anspruch 1, dadurch gekennzeichnet, dass dieser im Querschnitt rechteckig ausgebildet ist und auf der Unterseite eine sich bis in den Randbereich erstrekkende keilförmige Aussparung (20) aufweist.3. Chisel according to claim 1, characterized in that it is rectangular in cross section and has on the underside a wedge-shaped recess (20) extending into the edge region. 4. Meissel nach Anspruch 2 oder 3, dadurch gekennzeichnet, dass der Neigungswinkel (α) der Aussparung zwischen 15 und 45° liegt.4. Chisel according to claim 2 or 3, characterized in that the inclination angle (α) of the recess is between 15 and 45 °. 5. Meissel nach einem der Ansprüche 1 - 4, dadurch gekennzeichnet, dass im Bereich der Stanzkante vorerst eine Aussparung (22) mit grossem Neigungswinkel und innerhalb davon eine Aussparung (24) mit kleinerem Neigungswinkel ausgebildet ist.5. Chisel according to one of claims 1-4, characterized in that a recess (22) with a large inclination angle and a recess (24) with a smaller inclination angle is initially formed in the region of the punched edge. 6. Meissel nach einem der Ansprüche 1 - 5, dadurch gekennzeichnet, dass im Bereich der Stanzkante eine horizontale Randfläche (26) und eine innen anschliessende Aussparung (28) ausgebildet ist.6. Chisel according to one of claims 1-5, characterized in that a horizontal edge surface (26) and an inwardly adjoining recess (28) is formed in the region of the punching edge.
EP80810284A 1979-09-10 1980-09-09 Crust-breaking device for an electrolytic furnace Expired EP0025417B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80810284T ATE1824T1 (en) 1979-09-10 1980-09-09 IMPACTING DEVICE FOR BREAKING THE SOLID CRUST OF AN ELECTROLYTIC FURNACE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH815079 1979-09-10
CH8150/79 1979-09-10

Publications (2)

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EP0025417A1 true EP0025417A1 (en) 1981-03-18
EP0025417B1 EP0025417B1 (en) 1982-11-17

Family

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EP80810284A Expired EP0025417B1 (en) 1979-09-10 1980-09-09 Crust-breaking device for an electrolytic furnace

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US (1) US4416489A (en)
EP (1) EP0025417B1 (en)
JP (1) JPS5647581A (en)
AT (1) ATE1824T1 (en)
AU (1) AU539637B2 (en)
CA (1) CA1150188A (en)
DE (2) DE2943292A1 (en)
ES (1) ES258161Y (en)
GR (1) GR69697B (en)
IS (1) IS1172B6 (en)
NO (1) NO154434C (en)
NZ (1) NZ194873A (en)
YU (1) YU230980A (en)
ZA (1) ZA805337B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2465016A1 (en) * 1979-09-10 1981-03-20 Alusuisse DEVICE FOR SUPPLYING ELECTROLYTIC FURNACES
WO1997011818A1 (en) * 1995-09-29 1997-04-03 Bodo Hoppe Hammer

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0664610B2 (en) * 1987-10-12 1994-08-22 工業技術院長 Measurement method of posture angle and position of figure pattern by affine inverse transformation
US5873423A (en) * 1997-07-31 1999-02-23 Briese Industrial Technologies, Inc. Frustum cutting bit arrangement

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DE1186222B (en) * 1962-12-07 1965-01-28 Vmw Ranshofen Berndorf Ag Device for the automatic addition of aluminum oxide to aluminum electrolysis ovens
DE1194589B (en) * 1962-09-14 1965-06-10 Ardal Og Sunndal Verk Crust breaker
AT268708B (en) * 1963-03-04 1969-02-25 Alcan Aluminium Ltd Crust breaking device for aluminum electrolysis furnaces
AT280626B (en) * 1967-04-07 1970-04-27 Alusuisse Method and device for operating a furnace for the electrolytic production of aluminum

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US1880623A (en) * 1930-03-15 1932-10-04 Ingersoll Rand Co Broaching tool
US2423787A (en) * 1944-11-01 1947-07-08 Aluminum Co Of America Crust breaking apparatus
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DE1194589B (en) * 1962-09-14 1965-06-10 Ardal Og Sunndal Verk Crust breaker
DE1186222B (en) * 1962-12-07 1965-01-28 Vmw Ranshofen Berndorf Ag Device for the automatic addition of aluminum oxide to aluminum electrolysis ovens
AT268708B (en) * 1963-03-04 1969-02-25 Alcan Aluminium Ltd Crust breaking device for aluminum electrolysis furnaces
AT280626B (en) * 1967-04-07 1970-04-27 Alusuisse Method and device for operating a furnace for the electrolytic production of aluminum

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2465016A1 (en) * 1979-09-10 1981-03-20 Alusuisse DEVICE FOR SUPPLYING ELECTROLYTIC FURNACES
WO1997011818A1 (en) * 1995-09-29 1997-04-03 Bodo Hoppe Hammer

Also Published As

Publication number Publication date
ES258161U (en) 1981-11-16
JPS5647581A (en) 1981-04-30
DE3061110D1 (en) 1982-12-23
YU230980A (en) 1983-02-28
ATE1824T1 (en) 1982-12-15
ZA805337B (en) 1981-09-30
NO154434B (en) 1986-06-09
NZ194873A (en) 1984-12-14
GR69697B (en) 1982-07-08
ES258161Y (en) 1982-05-16
DE2943292A1 (en) 1981-03-19
NO802644L (en) 1981-03-11
US4416489A (en) 1983-11-22
IS1172B6 (en) 1984-12-28
NO154434C (en) 1986-09-17
CA1150188A (en) 1983-07-19
EP0025417B1 (en) 1982-11-17
AU539637B2 (en) 1984-10-11
AU6211080A (en) 1981-03-19
IS2582A7 (en) 1981-03-11

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