[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

EP0224851B1 - Electrode for electrochemical processes - Google Patents

Electrode for electrochemical processes Download PDF

Info

Publication number
EP0224851B1
EP0224851B1 EP86116354A EP86116354A EP0224851B1 EP 0224851 B1 EP0224851 B1 EP 0224851B1 EP 86116354 A EP86116354 A EP 86116354A EP 86116354 A EP86116354 A EP 86116354A EP 0224851 B1 EP0224851 B1 EP 0224851B1
Authority
EP
European Patent Office
Prior art keywords
valve metal
conductor
copper
alloy
aluminium
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
EP86116354A
Other languages
German (de)
French (fr)
Other versions
EP0224851A1 (en
Inventor
Reinhard Koch
Heinrich Simon
Albrecht Körbitz
Helmut Krebs
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.)
De Nora Deutschland GmbH
Original Assignee
Heraeus Elektroden GmbH
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 Heraeus Elektroden GmbH filed Critical Heraeus Elektroden GmbH
Priority to AT86116354T priority Critical patent/ATE47432T1/en
Publication of EP0224851A1 publication Critical patent/EP0224851A1/en
Application granted granted Critical
Publication of EP0224851B1 publication Critical patent/EP0224851B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/02—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
    • C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
    • C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
    • C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
    • C23F13/20—Conducting electric current to electrodes
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
    • C25D17/10—Electrodes, e.g. composition, counter electrode
    • C25D17/12—Shape or form

Definitions

  • the invention relates to a tubular electrode for electrolytic processes, in particular anode for galvanic processes or cathodic corrosion protection, with a current conductor made of an electrically highly conductive material, which is encased by a tubular valve metal body, which is connected in an electrically conductive manner to the current conductor and whose conductor is turned away from the current conductor Surface is provided with a pad made of electrocatalytic material.
  • valve metals In electrolytic processes which require a noble metal from the platinum group as electrochemically active electrode material, it is known to apply this to a carrier made of valve metal for economical use; Such valve metals have an extensive blocking effect in the case of anodic switching, according to which the current transfer in the electrolytes takes place only at the points at which the noble metal coating rests on the carrier. Since valve metals have a relatively high electrical resistance, it has been proposed several times to remove the function of the current supply of the electrode as much as possible from the material of the carrier and to guide the current supply to the carrier as close as possible to the outlet point in the electrolyte via material with high electrical conductivity .
  • DE-PS 913 768 describes electrodes made from combinations of tantalum as valve metal with metals of high electrical conductivity in which the tantalum forms only a relatively thin surface layer.
  • Such combinations consist of a base body coated with a closed, thin layer of tantalum or tantalum alloy made of electrically highly conductive metal, such as e.g. Silver, copper or aluminum.
  • the tantalum layer is coated with a thin layer of platinum or wrapped with a thin platinum wire, possibly in the form of a spiral.
  • AT-PS 212 284 describes the use of titanium as valve metal, which has an electrical resistance value that is about four times higher than that of tantalum.
  • a carrier body made of a core of copper, silver or aluminum should be used, which is covered with a titanium layer or a stronger titanium jacket. The sheathing shields the conductive core against the action of the electrolyte and at the same time achieves the current path through the poorly conductive titanium in the electrolyte over the shortest distance perpendicular to the direction of supply.
  • the electrocatalytically active electrode material made of platinum or a platinum metal is located on the carrier in the form of a closed or interrupted coating or in the form of a spiral of tape or wire.
  • an electrode for chlorine electrolysis is also known, in which an envelope made of a valve metal is applied to a copper core.
  • Valve metal body and core are interconnected by a fusion connection, plating process or spraying process, electrically conductive and mechanically fixed.
  • the usually existing blocking effect of the valve metal is to be eliminated.
  • valve metals used as carrier material for electrodes with their relatively poor electrical conductivity by current conductors as the core material, the current conductors being shielded from the action of the electrolyte by the valve metal body surrounding them.
  • the valve metals because of their relatively high price, always form only a relatively thin sheathing for a solid core conductor, the dimensions of the solid core conductor being predetermined by the required electrode dimensions. In the case of large-format electrodes in particular, this leads to an oversized conductor cross-section for the actual power line and to a relatively high weight due to the solidity of the core conductor.
  • the invention has for its object to build an electrode of high stability in lightweight construction with a current conductor sufficiently dimensioned for practical needs, which is used to supply power to a valve metal body designed as an enveloping body, the dimensions of which are completely independent of the format of the current conductor. Furthermore, electrodes should be easily assembled as individual elements to form larger electrode units.
  • the object is achieved in that the electrically conductive connection between the current conductor and the valve metal body takes place via at least two composite bodies arranged at a distance from one another, each composite body having a region made of valve metal and a region made of copper, aluminum or an alloy based on one of these metals and that the valve metal area with the valve metal body and the area made of copper, aluminum or alloy surrounds the current conductor in a ring shape and are electrically and mechanically firmly connected to the current conductor.
  • the composite body is connected to the valve metal body by a welded connection, while it forms a soldered, screwed or pressed connection with the region of the current conductor which it surrounds in a ring.
  • the area of the composite body consisting of the valve metal encloses in the form of a hollow cylinder the ring-shaped area made of copper, aluminum or an alloy based on one of these metals.
  • valve metal body to the current conductor provided with composite bodies. Due to the lightweight construction, high stability is achieved even when assembled into larger electrode units made up of several electrode elements.
  • Figure 1 a shows an electrode according to the invention in Longitudinal section
  • Figure 1 b the same electrode in a perspective elevation
  • Figure 2 shows an electrode with a double electrical connection.
  • the current conductor 1 which is made of a material with good electrical conductivity, is located in a cylindrically symmetrical valve metal body 2 which is sealed off from the outside and is arranged coaxially with the current conductor 1.
  • the axis of the conductor is designated 3.
  • the electrical connection between the current conductor 1 and the valve metal body 2 is produced by composite bodies 4, which are arranged at intervals on the current conductor 1 and form a welded joint 7 with the valve metal body.
  • the distances between the composite bodies are chosen so that the Joule heat losses in the valve metal body 2 do not exceed a predetermined value under normal current load; it is therefore a compromise between the smallest possible number of composite bodies and the greatest possible energy yield of the electrode.
  • the composite bodies 4 have an annular structure, the inner region 6 of the rings being made of copper, aluminum or an alloy based on one of these metals and surrounded by a region 5 of valve metal in the form of a jacket.
  • the area 5 consisting of valve metal is applied to the electrically highly conductive area by extrusion, shrinking, plating or thermal processes; extrusion is preferably used. Electrodes in the form of rods, which are common in practice, are supplied with a current which is in the range from 5 to 100 A / dm 2 of active anode area. With an inner diameter of the valve metal body 2 of, for example, 23 mm, an annular width of the composite body 4 of 15 mm results for design reasons.
  • the current conductor 1 is cylindrical and has a diameter of 12 mm, its length being less than the total length of the valve metal body 2. Copper or a copper alloy is used as the material for the current conductor 1, while the material of the valve metal body 2 or of the valve metal region 5 of the composite body 4 consists of titanium.
  • the current conductor 1 is shorter than the valve metal body 2, since the cup-shaped end 10 of the valve metal body 2 is supplied with current by a composite body 4, which is located at a predetermined distance from the end. At its other end, the current conductor 1 is mechanically and electrically conductively connected to the last composite body and a socket 12.
  • the socket 12 has the same basic structure as the other composite body 4, so that the outer surface 13 also consists of the material of the valve metal body.
  • the socket 12 protruding from the upper end of the valve metal body 2 is mistaken. Area of its outer surface 13 welded to the upper edge of the valve metal body 2.
  • the protruding end of the bushing 12 is accommodated in a recess 14 in a connecting part 15 and is welded to it in the edge region of the recess.
  • the distances between the composite bodies are 200 to 1000 mm, the distance between the cup-shaped end 10 and the next composite body 4 being reduced accordingly.
  • a partial electrode can be provided with a connecting element 19, which in turn is screwed in the direction of the axis 3 of the current conductor 1 to a threaded hole for receiving the other partial electrode, which is formed with a threaded bolt in the connecting element 18.
  • the two connecting elements 18, 19 are each connected to one another at their adjacent surfaces by a circumferential weld seam, in order to shield the connecting zone against entry of the electrolyte.
  • an electrode with a double connection from two straight partial electrodes and a U-shaped middle piece, as is explained in more detail with reference to FIG.
  • FIG. 1b shows the electrode according to the invention in a perspective view, the valve metal body being only partially shown for better understanding.
  • the current conductor 1 is provided with four composite bodies 4 which are arranged at regular intervals from one another.
  • Each composite body 4 supplies a jacket area of the valve metal body 2, the length of which corresponds to the respective distances between the composite bodies 4.
  • the length of the section to be supplied is correspondingly half as long as the distance between the composite bodies.
  • the soldered socket 12 can be seen, the outer jacket surface 13 of which is welded all around to the upper edge of the valve metal body 2.
  • the valve metal body 2 is provided at the points provided for welding between the composite body 4 and the valve metal body 2, each with at least one opening 16, in order to enable the composite bodies 4 to be positioned exactly within the valve metal body 2. After the respective welding process there are hermetically sealed welded connections 7 between the composite bodies 4 and the valve body 2 in the area of these openings, so that the current conductor 1 is shielded against any attack by the electrolyte.
  • the valve metal body 2 serves as a carrier of the electrocatalytic electrode material, not shown here, for example platinum or a metal of the platinum group.
  • FIG. 2 shows a U-shaped electrode with two current connections 20, which results in one increased resilience.
  • the two sub-electrodes each have the same basic structure in the area of their two upper composite bodies 4 as the electrode described in FIGS. 1a, 1b.
  • the composite body 4 'arranged in the middle, U-shaped area is connected to the current conductor 1 of the two partial electrodes by means of flexible current conductors 1' following the tube axis with the aid of the connecting elements explained in FIG. 1a.
  • a sheathed flexible copper cable is preferably used as the material for the flexible current conductor.
  • the object of the invention is preferably used in hard chromium plating systems, the material to be applied being dissolved in the electrolyte.
  • the subject of the invention as a counter electrode for the cathodic corrosion protection of ships, tanks, pipelines and drilling towers.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Mechanical Engineering (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
  • Prevention Of Electric Corrosion (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

1. A tubular electrode for electrolytic processes, in particular an anode for galvanic processes or cathodic anticorrosive protection, comprising a conductor of a material of good electrical conductivity, which is ensheated by a tubular valve metal element which is connected to the conductor in an electrically conductive manner and whose surface facing away from the conductor is provided with a coating of electrocatalytic material, characterized in that the electrically conductive connection between the conductor (1) and the valve metal element (2) is established via at least two composite elements (4) arranged with mutual spacing, each composite element (4) comprising a portion (5) of valve metal and a portion (6) of copper, aluminium or an alloy based on one of these metals and that the valve metal portion (5) with the valve metal element (2) and the portion (6) of copper, aluminium or the alloy, annularly surround the conductor (1) and are connected to the conductor in an electrically conductive and mechanically secure manner.

Description

Die Erfindung betrifft eine rohrförmige Elektrode für elektrolytische Verfahren, insbesondere Anode für galvanische Verfahren oder kathodischen Korrosionsschutz, mit einem Stromleiter aus einem elektrisch gut leitenden Werkstoff, der von einem rohrförmigen Ventilmetallkörper umhüllt ist, der elektrisch leitend mit dem Stromleiter verbunden ist und dessen dem Stromleiter abgekehrte Oberläche mit einer Auflage aus elektrokatalytischem Werkstoff versehen ist.The invention relates to a tubular electrode for electrolytic processes, in particular anode for galvanic processes or cathodic corrosion protection, with a current conductor made of an electrically highly conductive material, which is encased by a tubular valve metal body, which is connected in an electrically conductive manner to the current conductor and whose conductor is turned away from the current conductor Surface is provided with a pad made of electrocatalytic material.

Es ist bekannt, bei elektrolytischen Prozessen, welche ein Edelmetall der Platin-Gruppe als elektrochemisch aktives Elektrodenmaterial benötigen, dieses zwecks sparsamer Verwendung auf einen Träger aus Ventilmetall aufzubringen; solche Ventilmetalle besitzen bei anodischer Schaltung eine weitgehende Sperrwirkung, wonach der Stromübergang in den Elektrolyten nur an den Stellen erfolgt, an denen der Edelmetallüberzug auf dem Träger aufliegt. Da Ventilmetalle einen verhältnismäßig hohen elektrischen Widerstand aufweisen, wurde bereits mehrfach vorgeschlagen, die Funktion der Stromzufuhr der Elektrode soweit wie möglich aus dem Material des Trägers herauszulagern und die Stromzufuhr zum Träger so nahe wie möglich an die Austrittsstelle im Elektrolyten über Material hoher elektrischer Leitfähigkeit zu führen. So beschreibt die DE-PS 913 768 Elektroden aus Kombinationen von Tantal als Ventilmetall mit Metallen von hohem elektrischen Leitvermögen, in denen das Tantal nur eine verhältnismäßig dünne Oberflächenschicht bildet. Derartige Kombinationen bestehen aus einem mit einer geschlossenen, dünnen Schicht Tantal oder Tantal-Legierung überzogenen Grundkörper aus elektrisch gut leitendem Metall, wie z.B. Silber, Kupfer oder Aluminium. Für Prozesse, die als wirksame Elektrodenfläche Platin erfordern, wird die Tantalschicht mit einer dünnen Schicht Platin überzogen oder mit einem dünnen Platindraht gegebenenfalls in Form einer Spirale umwickelt.In electrolytic processes which require a noble metal from the platinum group as electrochemically active electrode material, it is known to apply this to a carrier made of valve metal for economical use; Such valve metals have an extensive blocking effect in the case of anodic switching, according to which the current transfer in the electrolytes takes place only at the points at which the noble metal coating rests on the carrier. Since valve metals have a relatively high electrical resistance, it has been proposed several times to remove the function of the current supply of the electrode as much as possible from the material of the carrier and to guide the current supply to the carrier as close as possible to the outlet point in the electrolyte via material with high electrical conductivity . For example, DE-PS 913 768 describes electrodes made from combinations of tantalum as valve metal with metals of high electrical conductivity in which the tantalum forms only a relatively thin surface layer. Such combinations consist of a base body coated with a closed, thin layer of tantalum or tantalum alloy made of electrically highly conductive metal, such as e.g. Silver, copper or aluminum. For processes that require platinum as an effective electrode surface, the tantalum layer is coated with a thin layer of platinum or wrapped with a thin platinum wire, possibly in the form of a spiral.

Weiterhin beschreibt die AT-PS 212 284 den Einsatz von Titan als Ventilmetall, welches gegenüber Tantal einen etwa viermal höheren elektrischen, spezifischen Widerstandswert besitzt. Um eine möglichst günstige Energieausbeute zu erzielen, soll ein Trägerkörper aus einem Kern von Kupfer, Silber oder Aluminium eingesetzt werden, welcher mit einer Titanschicht oder einem stärkeren Titanmantel überzogen ist. Durch die Ummantelung wird der leitfähige Kern gegen die Einwirkung des Elektrolyten abgeschirmt und gleichzeitig der Stromweg durch das elektrisch schlecht leitende Titan in den Elektrolyten über die kürzeste Entfernung senkrecht zur Zuleitungsrichtung erzielt. Auf dem Träger befindet sich in Form eines geschlossenen oder unterbrochenen Überzuges oder in Form einer Spirale von Band oder Draht der elektrokatalytisch wirksame Elektrodenwerkstoff aus Platin oder einem Platinmetall.Furthermore, AT-PS 212 284 describes the use of titanium as valve metal, which has an electrical resistance value that is about four times higher than that of tantalum. In order to achieve the best possible energy yield, a carrier body made of a core of copper, silver or aluminum should be used, which is covered with a titanium layer or a stronger titanium jacket. The sheathing shields the conductive core against the action of the electrolyte and at the same time achieves the current path through the poorly conductive titanium in the electrolyte over the shortest distance perpendicular to the direction of supply. The electrocatalytically active electrode material made of platinum or a platinum metal is located on the carrier in the form of a closed or interrupted coating or in the form of a spiral of tape or wire.

Aus der US-PS 1 970 804 ist weiterhin eine Elektrode für die Chlorelektrolyse bekannt, bei der auf einem Kupferkern eine Umhüllung aus einem Ventilmetall aufgebracht ist. Ventilmetallkörper und Kern sind miteinander durch eine Schmelzverbindung, Plattierverfahren oder Spritzverfahren, elektrisch leitend und mechanisch fest miteinander verbunden. Neben einer optimalen Stromzuleitung soll die üblicherweise vorliegende Sperrwirkung des Ventilmetalls eliminiert werden.From US Pat. No. 1,970,804, an electrode for chlorine electrolysis is also known, in which an envelope made of a valve metal is applied to a copper core. Valve metal body and core are interconnected by a fusion connection, plating process or spraying process, electrically conductive and mechanically fixed. In addition to an optimal power supply line, the usually existing blocking effect of the valve metal is to be eliminated.

Es ist somit bekannt, die als Trägermaterial für Elektroden eingesetzten Ventilmetalle mit ihrer verhältnismäßig schlechten elektrischen Leitfähigkeit durch Stromleiter als Kernmaterial zu ergänzen, wobei die Stromleiter gegen die Einwirkung des Elektrolyten durch den sie umgebenden Ventilmetallkörper abgeschirmt sind. Als nachteilig erweist es sich dabei insbesondere, daß die Ventilmetalle aufgrund ihres verhältnismäßig hohen Preises stets nur eine verhältnismäßig dünne Ummantelung für einen massiven Kernleiter bilden, wobei die Ausmaße des massiv ausgeführten Kernleiters durch die erforderlichen Elektrodenabmessungen vorgegeben sind. Dies führt insbesondere bei großformatigen Elektroden zu einem für die eigentliche Stromleitung überdimensionierten Stromleiterquerschnitt und zu einem verhältnismäßig hohen Gewicht aufgrund der Massivität des Kernleiters.It is thus known to supplement the valve metals used as carrier material for electrodes with their relatively poor electrical conductivity by current conductors as the core material, the current conductors being shielded from the action of the electrolyte by the valve metal body surrounding them. It proves particularly disadvantageous that the valve metals, because of their relatively high price, always form only a relatively thin sheathing for a solid core conductor, the dimensions of the solid core conductor being predetermined by the required electrode dimensions. In the case of large-format electrodes in particular, this leads to an oversized conductor cross-section for the actual power line and to a relatively high weight due to the solidity of the core conductor.

Die Erfindung stellt sich die Aufgabe, eine Elektrode hoher Stabilität in Leichtbauweise mit einem für die praktischen Bedürfnisse ausreichend dimensionierten Stromleiter aufzubauen, welcher zur Stromversorgung eines als Hüllkörper ausgeführten Ventilmetallkörpers dient, dessen Ausmaße vom Format des Stromleiters völlig unabhängig ist. Ferner sollen Elektroden als Einzelelemente auf einfache Weise zu größeren Elektrodeneinheiten zusammenzusetzen sein.The invention has for its object to build an electrode of high stability in lightweight construction with a current conductor sufficiently dimensioned for practical needs, which is used to supply power to a valve metal body designed as an enveloping body, the dimensions of which are completely independent of the format of the current conductor. Furthermore, electrodes should be easily assembled as individual elements to form larger electrode units.

Die Aufgabe wird dadurch gelöst, daß die elektrisch leitende Verbindung zwischen Stromleiter und Ventilmetallkörper über wenigstens zwei im Abstand zueinander angeordnete Verbundkörper erfolgt, wobei jeder Verbundkörper einen Bereich aus Ventilmetall und einen Bereich aus Kupfer, Aluminium oder einer Legierung auf der Basis eines dieser Metalle aufweist und daß der Ventilmetall-Bereich mit dem Ventilmetallkörper und der Bereich aus Kupfer, Aluminium oder der Legierung den Strornleiter ringförmig umschließt und mit dem Stromleiter elektrisch leitend und mechanisch fest verbunden sind.The object is achieved in that the electrically conductive connection between the current conductor and the valve metal body takes place via at least two composite bodies arranged at a distance from one another, each composite body having a region made of valve metal and a region made of copper, aluminum or an alloy based on one of these metals and that the valve metal area with the valve metal body and the area made of copper, aluminum or alloy surrounds the current conductor in a ring shape and are electrically and mechanically firmly connected to the current conductor.

In einer bevorzugten Ausführungsform ist der Verbundkörper durch eine Schweißverbindung mit dem Ventilmetallkörper verbunden, während er mit dem von ihm ringförmig umschlossenen Bereich des Stromleiters eine Löt-, Schraub- oder Preßverbindung bildet. Der aus dem Ventilmetall bestehende Bereich des Verbundkörpers umschließt in Form eines Hohlzylinders den ringförmigen Bereich aus Kupfer, Aluminium oder einer Legierung auf der Basis eines dieser Metalle.In a preferred embodiment, the composite body is connected to the valve metal body by a welded connection, while it forms a soldered, screwed or pressed connection with the region of the current conductor which it surrounds in a ring. The area of the composite body consisting of the valve metal encloses in the form of a hollow cylinder the ring-shaped area made of copper, aluminum or an alloy based on one of these metals.

Als vorteilhaft erweist sich die einfache Herstellung durch Aufschieben und anschließende Verschweißung des Ventilmetallkörpers auf dem mit Verbundkörpern versehenen Stromleiter. Aufgrund der Leichtbauweise wird eine hohe Stabilität auch beim Zusammenbau zu größeren Elektrodeneinheiten aus mehreren Elektrodenelementen erzielt.The simple manufacture by pushing on and then welding the valve metal body to the current conductor provided with composite bodies has proven to be advantageous. Due to the lightweight construction, high stability is achieved even when assembled into larger electrode units made up of several electrode elements.

Im folgenden ist der Gegenstand der Erfindung anhand der Figuren 1a, 1 b und 2 näher erläutert.The subject matter of the invention is explained in more detail below with reference to FIGS. 1a, 1b and 2.

Figur 1 a zeigt eine erfindungsgemäße Elektrode in Längsschnitt, Figur 1 b die gleiche Elektrode in einem perspektivischen Aufriß. Figur 2 zeigt eine Elektrode mit doppeltem elektrischem Anschluß.Figure 1 a shows an electrode according to the invention in Longitudinal section, Figure 1 b the same electrode in a perspective elevation. Figure 2 shows an electrode with a double electrical connection.

Gemäß Figur 1 a befindet sich der aus einem Werkstoff guter elektrischer Leitfähigkeit bestehende Stromleiter 1 in einem gegenüber dem Außenraum abgeschlossenen zylindersymmetrischen Ventilmetallkörper 2, welcher koaxial zum Stromleiter 1 angeordnet ist. Die Achse des Stromleiters ist mit 3 bezeichnet.According to FIG. 1 a, the current conductor 1, which is made of a material with good electrical conductivity, is located in a cylindrically symmetrical valve metal body 2 which is sealed off from the outside and is arranged coaxially with the current conductor 1. The axis of the conductor is designated 3.

Da der Innendurchmesser des Ventilmetallkörpers größer ist als die Ausdehnung des Stromleiters 1 wird die elektrische Verbindung zwischen dem Stromleiter 1 und dem Ventilmetallkörper 2 durch Verbundkörper 4 hergestellt, welche in Abständen auf dem Stromleiter 1 angeordnet sind und mit dem Ventilmetallkörper eine Schweißverbindung 7 bilden. Die Abstände der Verbundkörper zueinander werden dabei so gewählt, daß bei üblicher Strombelastung die Jouleschen Wärmeverluste in dem Ventilmetallkörper 2 einen vorgegebenen Wert nicht überschreiten; es handelt sich somit um einen Kompromiß zwischen einer möglichst geringen Anzahl von Verbundkörpern und einer möglichst großen Energieausbeute der Elektrode.Since the inside diameter of the valve metal body is larger than the extension of the current conductor 1, the electrical connection between the current conductor 1 and the valve metal body 2 is produced by composite bodies 4, which are arranged at intervals on the current conductor 1 and form a welded joint 7 with the valve metal body. The distances between the composite bodies are chosen so that the Joule heat losses in the valve metal body 2 do not exceed a predetermined value under normal current load; it is therefore a compromise between the smallest possible number of composite bodies and the greatest possible energy yield of the electrode.

Die Verbundkörper 4 besitzen eine ringförmige Struktur, wobei der innere Bereich 6 der Ringe aus Kupfer, Aluminium oder einer Legierung auf der Basis eines dieser Metalle besteht und von einem Bereich 5 aus Ventilmetall mantelförmig umgeben ist. Der aus Ventilmetall bestehende Bereich 5 ist durch Strangpressen, Schrumpfung, Plattierung oder thermische Verfahren auf den elektrisch gut leitenden Bereich aufgebracht; vorzugsweise wird Strangpressen eingesetzt. In der Praxis übliche Elektroden in Stabform werden mit einem Strom gespeist, welcher im Bereich von 5 bis 100 A/dm2 aktive Anodenfläche liegt. Bei einem Innendurchmesser des Ventilmetallkörpers 2 von beispielsweise 23 mm ergibt sich aus konstruktiven Gründen eine Ringbreite des Verbundkörpers 4 von 15 mm. Der Stromleiter 1 ist zylindrisch ausgebildet und weist einen Durchmesser von 12 mm auf, wobei seine Länge geringer ist als die Gesamtlänge des Ventilmetallkörpers 2. Als Werkstoff für den Stromleiter 1 wird Kupfer oder eine Kupfer-Legierung eingesetzt, während der Werkstoff des Ventilmetallkörpers 2 bzw. des Ventilmetall-Bereichs 5 des Verbundkörpers 4 aus Titan besteht.The composite bodies 4 have an annular structure, the inner region 6 of the rings being made of copper, aluminum or an alloy based on one of these metals and surrounded by a region 5 of valve metal in the form of a jacket. The area 5 consisting of valve metal is applied to the electrically highly conductive area by extrusion, shrinking, plating or thermal processes; extrusion is preferably used. Electrodes in the form of rods, which are common in practice, are supplied with a current which is in the range from 5 to 100 A / dm 2 of active anode area. With an inner diameter of the valve metal body 2 of, for example, 23 mm, an annular width of the composite body 4 of 15 mm results for design reasons. The current conductor 1 is cylindrical and has a diameter of 12 mm, its length being less than the total length of the valve metal body 2. Copper or a copper alloy is used as the material for the current conductor 1, while the material of the valve metal body 2 or of the valve metal region 5 of the composite body 4 consists of titanium.

Der Stromleiter 1 ist kürzer als der Ventilmetallkörper 2, da das becherförmige Ende 10 des Ventilmetallkörpers 2 von einem Verbundkörper 4 mit Strom versorgt wird, welcher sich in einem vorgegebenen Abstand zu dem Ende befindet. An seinem anderen Ende ist der Stromleiter 1 mit dem letzten Verbundkörper und einer Buchse 12 mechanisch und elektrisch leitend fest verbunden.The current conductor 1 is shorter than the valve metal body 2, since the cup-shaped end 10 of the valve metal body 2 is supplied with current by a composite body 4, which is located at a predetermined distance from the end. At its other end, the current conductor 1 is mechanically and electrically conductively connected to the last composite body and a socket 12.

Die Buchse 12 weist den gleichen prinzipiellen Aufbau auf wie die übrigen Verbundkörper 4, so daß die Mantelfläche 13 ebenfalls aus dem Material des Ventilmetallkörpers besteht. Die aus dem oberen Ende des Ventilmetallkörpers 2 herausragende Buchse 12 ist irr. Bereich ihrer Mantelfläche 13 mit dem oberen Rand des Ventilmetallkörpers 2 verschweißt. Das hinausragende Ende der Buchse 12 ist in einer Aussparung l4einesAnschlußteils 15untergebracht und im Randbereich der Aussparung mit diesem verschweißt.The socket 12 has the same basic structure as the other composite body 4, so that the outer surface 13 also consists of the material of the valve metal body. The socket 12 protruding from the upper end of the valve metal body 2 is mistaken. Area of its outer surface 13 welded to the upper edge of the valve metal body 2. The protruding end of the bushing 12 is accommodated in a recess 14 in a connecting part 15 and is welded to it in the edge region of the recess.

Zur besseren Übersicht wurden in Figur 1 a nur wenige Segmente der erfindungsgemäßen Elektrode dargestellt. In der Praxis betragen die Abstände zwischen den Verbundkörpern 200 bis 1000 mm, wobei zwischen dem becherförmigen Ende 10 und dem nächsten Verbundkörper 4 der Abstand entsprechend verringert ist.For a better overview, only a few segments of the electrode according to the invention were shown in FIG. 1a. In practice, the distances between the composite bodies are 200 to 1000 mm, the distance between the cup-shaped end 10 and the next composite body 4 being reduced accordingly.

In einer weiteren erfindungsgemäßen Ausführungsform ist es möglich, zwei oder mehrere Teilelektroden, die an ihren Enden jeweils ein Verbindungselement in Form eines Verbundkörpers aufweisen miteinander zu verbinden. So kann beispielsweise gemäß Figur 1 a eine Teilelektrode mit einem Verbindungselement 19 versehen sein, welches seinerseits in Richtung der Achse 3 des Stromleiters 1 ein Gewindeloch zur Aufnahme der anderen Teilelektrode, die mit einem Gewindebolzen im Verbindungselement 18 ausgebildet ist, verschraubt werden. Nach dem Verschrauben werden die beiden Verbindungselemente 18, 19 jeweils an ihren angrenzenden Flächen durch eine umlaufende Schweißnaht miteinander verbunden, um somit die Verbindungszone gegen Eintritt des Elektrolyten abzuschirmen.In a further embodiment according to the invention, it is possible to connect two or more partial electrodes, which each have a connecting element in the form of a composite body at their ends. For example, according to FIG. 1 a, a partial electrode can be provided with a connecting element 19, which in turn is screwed in the direction of the axis 3 of the current conductor 1 to a threaded hole for receiving the other partial electrode, which is formed with a threaded bolt in the connecting element 18. After screwing, the two connecting elements 18, 19 are each connected to one another at their adjacent surfaces by a circumferential weld seam, in order to shield the connecting zone against entry of the electrolyte.

Mit Hilfe solcher Elemente ist es auch möglich, aus zwei jeweils geraden Teilelektroden und einem U-förmigen Mittelstück eine Elektrode mit Doppelanschluß aufzubauen, wie sie anhand Figur 2 näher erläutert ist.With the help of such elements, it is also possible to construct an electrode with a double connection from two straight partial electrodes and a U-shaped middle piece, as is explained in more detail with reference to FIG.

Figur 1b zeigt in einer perspektivischen Darstellung die erfindungsgemäße Elektrode, wobei zur besseren Verständlichkeit der Ventilmetallkörper nur teilweise dargestellt wurde. Gemäß dieser Figur ist der Stromleiter 1 mit vier Verbundkörpern 4 versehen, welche in regelmäßigen Abständen zueinander angeordnet sind. Dabei versorgt jeder Verbundkörper 4 jeweils einen Mantelbereich des Ventilmetallkörpers 2, dessen Länge den jeweiligen Abständen der Verbundkörper 4 entspricht. Zwischen dem becherförmigen Ende 10 des Ventilmetallkörpers 2 und dem benachbarten Verbundkörper ist die Länge des zu versorgenden Teilstückes entsprechend halb so lang wie der Abstand zwischen den Verbundkörpern. Am anderen Ende des Stromleiters 1 ist die aufgelötete Buchse 12 erkennbar, deren äußere Mantelfläche 13 mit dem oberen Rand des Ventilmetallkörpers 2 rundum verschweißt ist. Der Ventilmetallkörper 2 ist an den für die Verschweißung vorgesehenen Punkten zwischen Verbundkörper 4 und Ventilmetallkörper 2 mit jeweils wenigstens einer Öffnung 16 versehen, um eine exakte Positionierung der Verbundkörper 4 innerhalb des Ventilmetallkörpers 2 zu ermöglichen. Nach dem jeweiligen Schweißvorgang liegen im Bereich dieser Öffnungen jeweils hermetisch dichte Schweißverbindungen 7 zwischen den Verbundkörpern 4 und dem Ventilkörper 2 vor, so daß der Stromleiter 1 gegen jeglichen Angriff des Elektrolyten abgeschirmt ist. Der Ventilmetallkörper 2 dient als Träger des hier nicht näher dargestellten elektrokatalytischen Elektrodenmaterials beispielsweise Platin bzw. eines Metalls der Platin-Gruppe.FIG. 1b shows the electrode according to the invention in a perspective view, the valve metal body being only partially shown for better understanding. According to this figure, the current conductor 1 is provided with four composite bodies 4 which are arranged at regular intervals from one another. Each composite body 4 supplies a jacket area of the valve metal body 2, the length of which corresponds to the respective distances between the composite bodies 4. Between the cup-shaped end 10 of the valve metal body 2 and the adjacent composite body, the length of the section to be supplied is correspondingly half as long as the distance between the composite bodies. At the other end of the current conductor 1, the soldered socket 12 can be seen, the outer jacket surface 13 of which is welded all around to the upper edge of the valve metal body 2. The valve metal body 2 is provided at the points provided for welding between the composite body 4 and the valve metal body 2, each with at least one opening 16, in order to enable the composite bodies 4 to be positioned exactly within the valve metal body 2. After the respective welding process there are hermetically sealed welded connections 7 between the composite bodies 4 and the valve body 2 in the area of these openings, so that the current conductor 1 is shielded against any attack by the electrolyte. The valve metal body 2 serves as a carrier of the electrocatalytic electrode material, not shown here, for example platinum or a metal of the platinum group.

In Figur 2 ist eine U-förmige Elektrode mit zwei Stromanschlüssen 20 dargestellt, woraus sich eine erhöhte Belastbarkeit ergibt. Die beiden Teilelektroden weisen jeweils im Bereich ihrer beiden oberen Verbundkörper 4 den gleichen prinzipiellen Aufbau auf wie die in Figur 1a, 1b beschriebene Elektrode. Der im mittleren, U-förmigen Bereich angeordnete Verbundkörper 4' ist jedoch durch flexible, der Rohrachse folgende Stromleiter 1' mit dem Stromleiter 1 der beiden Teilelektroden mit Hilfe der in Figur 1 a erläuterten Verbindungselemente verbunden. Mit Hilfe der in Figur 2 dargestellten Anordnung ist es möglich, auf engem Raum eine verhältnismäßig große elektrochemisch aktive Fläche zu bilden. Als Material für den flexiblen Stromleiter wird vorzugsweise ein ummanteltes flexibles Kupfer-Kabel eingesetzt.FIG. 2 shows a U-shaped electrode with two current connections 20, which results in one increased resilience. The two sub-electrodes each have the same basic structure in the area of their two upper composite bodies 4 as the electrode described in FIGS. 1a, 1b. However, the composite body 4 'arranged in the middle, U-shaped area is connected to the current conductor 1 of the two partial electrodes by means of flexible current conductors 1' following the tube axis with the aid of the connecting elements explained in FIG. 1a. With the aid of the arrangement shown in FIG. 2, it is possible to form a relatively large electrochemically active area in a small space. A sheathed flexible copper cable is preferably used as the material for the flexible current conductor.

Der Gegenstand der Erfindung wird vorzugsweise in Hartverchromungsanlagen eingesetzt, wobei das aufzubringende Material im Elektrolyten gelöst ist.The object of the invention is preferably used in hard chromium plating systems, the material to be applied being dissolved in the electrolyte.

Weiterhin ist es möglich den Gegenstand der Erfindung als Gegenelektrode für den kathodischen Korrosionsschutz von Schiffen, Tanks, Rohrleitungen und Bohrtürmen einzusetzen.Furthermore, it is possible to use the subject of the invention as a counter electrode for the cathodic corrosion protection of ships, tanks, pipelines and drilling towers.

Claims (6)

1. A tubular electrode for electrolytic processes, in particular an anode for galvanic processes or cathodic anticorrosive protection, comprising a conductor of a material of good electrical conductivity, which is ensheathed by a tubular valve metal element which is connected to the conductor in an electrically conductive manner and whose surface facing away from the conductor is provided with a coating of electrocatalytic material, characterized in that the electrically conductive connection between the conductor (1) and the valve metal element (2) is established via at least two composite elements (4) arranged with mutual spacing, each composite element (4) comprising a portion (5) of valve metal and a portion (6) of copper, aluminium or an alloy based on one of these metals and that the valve metal portion (5) with the valve metal element (2) and the portion (6) of copper, aluminium or the alloy, annularly surround the conductor (1) and are connected to the conductor in an electrically conductive and mechanically secure manner.
2. An electrode according to claim 1, characterized in that the valve metal portion (5) of the composite element (4) is connected to the valve metal element (2) by means of a fusion joint (7).
3. An electrode according to claim 1 or 2, characterized in that the portion (6) of the composite element (4) consisting of copper, aluminium or the alloy has at least one recess (8) to receive the conductor (1).
4. An electrode according to claim 3, characterized in that the portion (5) of the composite element (4) consisting of valve metal is placed on the portion (6) consisting of copper, aluminium or the alloy.
5. An electrode according to claim 4, characterized in that the portion (6) of the composite element (4) consisting of copper, aluminium or the alloy is enclosed jacket-fashion by the portion (5) of valve metal.
6. An electrode according to one or more of the preceding claims, characterized in that the valve metal consists of titanium, tantalum, niobium or an alloy based on one of these metals.
EP86116354A 1985-11-27 1986-11-25 Electrode for electrochemical processes Expired EP0224851B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86116354T ATE47432T1 (en) 1985-11-27 1986-11-25 ELECTRODE FOR ELECTROCHEMICAL PROCESSES.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3541845A DE3541845C1 (en) 1985-11-27 1985-11-27 Tubular electrode for electrolytic processes
DE3541845 1985-11-27

Publications (2)

Publication Number Publication Date
EP0224851A1 EP0224851A1 (en) 1987-06-10
EP0224851B1 true EP0224851B1 (en) 1989-10-18

Family

ID=6286930

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86116354A Expired EP0224851B1 (en) 1985-11-27 1986-11-25 Electrode for electrochemical processes

Country Status (3)

Country Link
EP (1) EP0224851B1 (en)
AT (1) ATE47432T1 (en)
DE (2) DE3541845C1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6998031B1 (en) * 1999-07-01 2006-02-14 Atraverda Limited Electrode
GB9915420D0 (en) * 1999-07-01 1999-09-01 Atraverda Ltd Electrode
GB0005377D0 (en) 2000-03-06 2000-04-26 Atraverda Ltd Electrode

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1970804A (en) * 1932-12-24 1934-08-21 Paul C Kerk Electrode for electrolytic baths
GB1468670A (en) * 1973-08-02 1977-03-30 Ici Ltd Anodes
US4256810A (en) * 1978-12-04 1981-03-17 Gould Inc. High conductivity titanium electrode
WO1983000511A1 (en) * 1981-08-05 1983-02-17 Toyota Motor Co Ltd Electrode for use in cationic electrodeposition coating and coating method using the same
US4486288A (en) * 1982-03-11 1984-12-04 Linder Bjoern H Oxide anode for use in impressed current cathodic corrosion protection
JPS59193866U (en) * 1983-06-13 1984-12-22 高安　清澄 insoluble lead electrode
IT1163581B (en) * 1983-06-23 1987-04-08 Oronzio De Nora Sa PROCEDURE FOR CARRYING OUT THE ELECTRICAL CONNECTION OF NON-CORRODIBLE ANODES TO THE CORRODIBLE SOUL OF THE POWER CORD
IT1170053B (en) * 1983-12-23 1987-06-03 Oronzio De Nora Sa PRE-PACKED DISPERSER ANODE WITH BACKFILL IN FLEXIBLE STRUCTURE FOR CATHODIC PROTECTION WITH IMPRESSED CURRENTS

Also Published As

Publication number Publication date
ATE47432T1 (en) 1989-11-15
DE3666465D1 (en) 1989-11-23
DE3541845C1 (en) 1987-01-08
EP0224851A1 (en) 1987-06-10

Similar Documents

Publication Publication Date Title
EP1730813B1 (en) Method for joining a connecting element to an electric conductor made of aluminium and electric conductor produced according to said method
EP0089475B1 (en) Coated valve metal anode for electrolytical recuperation of metals or metal oxides
EP0036677B1 (en) Electrolysis cell
DE2812055C2 (en) Bipolar electrode
DE1191136B (en) Hygrometer cell
DE2046479B2 (en) ANODE ARRANGEMENT IN AN ELECTROLYSIS CELL
EP0224851B1 (en) Electrode for electrochemical processes
EP0141353A2 (en) Electrochemical storage cell
DE3406797C2 (en) Coated valve metal anode for the electrolytic extraction of metals or metal oxides
EP0436078B1 (en) Anode device for electrolytic cell
DE2506285C3 (en) Process for the production of an electrode plate for the electrowinning of non-ferrous metals
DE2307189C3 (en) High pressure discharge lamp
DE3528587C2 (en)
DE2627732B2 (en) Roller for the continuous electrolytic treatment of strip-shaped metallic materials
DD144174A1 (en) ELECTROLYSIS CELL AND METHOD FOR THE MANUFACTURE THEREOF
DE3406777C2 (en) Coated valve metal anode for the electrolytic extraction of metals or metal oxides
DE4241485C1 (en) Cathode for copper@ electrorefining or electrowinning - comprises steel plate welded to copper@ hanger bar surface by nickel@- copper@ weld metal
DE3045594C2 (en)
DE2721958A1 (en) Metal electrode for electrolytic mfr. of chlorine - has metal bars with high conductivity embedded in tubes with low conductivity
DE3913063C2 (en) Electron collector for an electron beam tube, especially a traveling wave tube
DE2820033A1 (en) CORROSION PROTECTION ANODE
DE4419864A1 (en) Uniform thickness internal chromium@ plating for gun barrels and chambers
DE4025253C2 (en) Current feeder for an electrode
AT212284B (en) Insoluble electrode
AT249086B (en) Electrical conductor and process for its manufacture

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19861205

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

17Q First examination report despatched

Effective date: 19880707

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19891018

Ref country code: NL

Effective date: 19891018

Ref country code: BE

Effective date: 19891018

REF Corresponds to:

Ref document number: 47432

Country of ref document: AT

Date of ref document: 19891115

Kind code of ref document: T

ET Fr: translation filed
REF Corresponds to:

Ref document number: 3666465

Country of ref document: DE

Date of ref document: 19891123

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19891130

Ref country code: LI

Effective date: 19891130

Ref country code: CH

Effective date: 19891130

ITF It: translation for a ep patent filed
GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19901018

Year of fee payment: 5

ITTA It: last paid annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19921001

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19921019

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19921124

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19921127

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19931125

Ref country code: AT

Effective date: 19931125

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19931125

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19940729

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20051125