EP0074464A1 - Apparatus for cleaning the inner walls of metallic tubular systems by electropolishing by means of moving electrodes - Google Patents

Apparatus for cleaning the inner walls of metallic tubular systems by electropolishing by means of moving electrodes Download PDF

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Publication number
EP0074464A1
EP0074464A1 EP82104946A EP82104946A EP0074464A1 EP 0074464 A1 EP0074464 A1 EP 0074464A1 EP 82104946 A EP82104946 A EP 82104946A EP 82104946 A EP82104946 A EP 82104946A EP 0074464 A1 EP0074464 A1 EP 0074464A1
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EP
European Patent Office
Prior art keywords
electrode
electropolishing
cleaning
inner walls
area
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP82104946A
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German (de)
French (fr)
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EP0074464B1 (en
Inventor
Manfred Kienhöfer
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Forschungszentrum Karlsruhe GmbH
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Kernforschungszentrum Karlsruhe GmbH
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
    • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
    • G21F9/001—Decontamination of contaminated objects, apparatus, clothes, food; Preventing contamination thereof
    • G21F9/002—Decontamination of the surface of objects with chemical or electrochemical processes
    • G21F9/004—Decontamination of the surface of objects with chemical or electrochemical processes of metallic surfaces
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F3/00—Electrolytic etching or polishing
    • C25F3/16—Polishing

Definitions

  • the invention relates to a method for cleaning the inner walls of metallic line systems by electropolishing with the aid of moving electrodes and a device for carrying out the method.
  • the invention has for its object to provide a method and a device with which (which) a metallic pipe system can be cleaned, without having to dismantle it.
  • pipe system should be understood here: a system of straight and curved pipes, including the associated shut-off devices, such as ball valves, slides or the like.
  • the process should also be able to successfully clean rising and falling pipes immediately.
  • the method and the device should be usable in particular for the decontamination of radioactive contaminated line systems.
  • the object is achieved in that the electrolyte is poured into the section of the pipe system to be cleaned and the electrolysis is carried out with the aid of an elastic electrode consisting of spiral wire or a coiled strip.
  • the device according to the invention for carrying out the method is characterized by an elastic electrode consisting of a spiral wire or a coiled ribbon, and by a plurality of insulating spacers, which are arranged on the electrode in a fixed or displaceable manner, at least in the electrode area.
  • the device there is a spacer at the head and at the other end of the electrode with an area that is greater by a factor of> 1 than that of the spacer (s) within the electrode area, but smaller area than the smallest corresponds to the traversed cross section of the line system.
  • the electrodes Due to the elasticity of the electrodes, an adaptation to curved surfaces is possible. As a result, disassembly of the pipes to be polished is no longer necessary, and it is possible to work with elbows and sliders as well as in inclined lines.
  • FIG. 2 Another embodiment of the device according to the invention is shown in FIG. 2, in which the electrode 4 a is designed in the form of a coiled stainless steel strip.
  • an approximately 300 mm long electrode 4a was produced, which was fitted with spacers 5 and 6 made of Teflon. So that one with radioactive contamination Contaminated pipe system 1 made of stainless steel, consisting of 3x1 m long pipes, 0 100 mm, 2 elbows and 1 ball valve on the inside can be freed of its radioactive contamination by electropolishing.
  • the line system 1 was placed in a large tub which was filled with an electrolyte of phosphoric and sulfuric acid, and the electrode 4a was pulled through at a speed of 5 cm / min. Direct current of 10-20 A / dm 2 was used. In this way it was possible to achieve a decontamination factor of around 500.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Food Science & Technology (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Cleaning In General (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Abstract

1. Device for cleaning of the internal walls of metallic pipework by electropolishing with the help of mobile electrodes consisting of an elastic electrode (4, 4a) made from a spiral wire or a helical filament, and several insulated spacers (5, 6) provided on the electrode either firmly attached or mobile, at least in the electrode zone.

Description

Die Erfindung betrifft ein Verfahren zur Reinigung der Innenwände von metallischen Leitungssystemen durch Elektropolieren mit Hilfe bewegter Elektroden und eine Vorrichtung zur Durchführung des Verfahrens.The invention relates to a method for cleaning the inner walls of metallic line systems by electropolishing with the aid of moving electrodes and a device for carrying out the method.

Das Entfernen von Verunreinigungen von metallischen Oberflächen, die schwer zugänglich bzw. erreichbar sind, wie z.B. die Innenwände von Rohren bzw. anderen Elementen von metallischen Leitungssystemen, insbesondere die Dekontamination von radioaktiven Verunreinigungen in solchen Systemen, war bisher nicht in jedem Falle mit gutem Erfolg bzw. zufriedenstellend auszuführen. Eines der gebräuchlichsten Verfahren hierfür ist das Elektropolieren. Jedoch konnten bisher nur wenige Meter lange demontierte Rohre mit beweglichen Elektroden innenseitig behandelt werden. Dazu wurden sowohl das gesamte Eintauchen des Rohres in den Elektrolyten als auch das Füllen von zuvor abgedichteten Kammern im Rohr (Rohrstücken) angewendet (R.P. Allen und H.W. Arrowsmith, Materials Performance, Vol. 18, No. 11, Seiten 21 bis 26 (1979)).Removing contaminants from metallic surfaces that are difficult to access, such as The inner walls of pipes or other elements of metallic piping systems, in particular the decontamination of radioactive contaminants in such systems, have so far not always been able to be carried out successfully or satisfactorily. One of the most common methods for this is electropolishing. However, previously dismantled pipes with movable electrodes could only be treated on the inside. For this purpose, both the entire immersion of the tube in the electrolyte and the filling of previously sealed chambers in the tube (tube pieces) were used (RP Allen and HW Arrowsmith, Materials Performance, Vol. 18, No. 11, pages 21 to 26 (1979) ).

Einer der gravierenden Nachteile dieses Verfahrens bestand in der Notwendigkeit, die zu reinigenden Rohre vor dem Elektropolieren ausbauen zu müssen. Außerdem war es nicht möglich, über mehrere Krümmer hinweg oder gar durch Absperrschieber bzw. Hähne hindurchzufahren.One of the serious disadvantages of this process was the need to remove the pipes to be cleaned before electropolishing. In addition, it was not possible to drive across multiple elbows or even through gate valves or taps.

Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren und eine Vorrichtung zu schaffen, mit welchem (welcher) ein metallisches Leitungssystem gereinigt werden kann, ohne es demontieren zu müssen. Unter Leitungssystem soll hier verstanden werden: Ein System von geraden und gekrümmten Rohren, einschließlich der zugehörigen Absperrorgane, wie z.B. Kugelhähne, Schieber oder ähnliches. Mit dem Verfahren sollen auch steigende bzw. fallende Leitungen gleich erfolgreich gereinigt werden können. Das Verfahren und die Vorrichtung sollen insbesondere für die Dekontamination von radioaktiv verunreinigter Leitungssysteme verwendbar sein.The invention has for its object to provide a method and a device with which (which) a metallic pipe system can be cleaned, without having to dismantle it. The term pipe system should be understood here: a system of straight and curved pipes, including the associated shut-off devices, such as ball valves, slides or the like. The process should also be able to successfully clean rising and falling pipes immediately. The method and the device should be usable in particular for the decontamination of radioactive contaminated line systems.

Die Aufgabe wird erfindungsgemäß dadurch gelöst, daß man den Elektrolyten in den zu reinigenden Abschnitt des Leitungssystems einfüllt und die Elektrolyse mit Hilfe einer elastischen, aus spiralförmigem Draht oder aus gewendeltem Band bestehende Elektrode durchführt.The object is achieved in that the electrolyte is poured into the section of the pipe system to be cleaned and the electrolysis is carried out with the aid of an elastic electrode consisting of spiral wire or a coiled strip.

Die erfindungsgemäße Vorrichtung zur Durchführung des Verfahrens ist gekennzeichnet durch eine elastische, aus einem spiralförmigen Draht oder einem gewendelten Band bestehende Elektrode, sowie durch mehrere, zumindest im Elektrodenbereich fest oder verschiebbar auf der Elektrode angeordnete, isolierende Abstandshalter.The device according to the invention for carrying out the method is characterized by an elastic electrode consisting of a spiral wire or a coiled ribbon, and by a plurality of insulating spacers, which are arranged on the electrode in a fixed or displaceable manner, at least in the electrode area.

In einer vorteilhaften Ausbildung der erfindungsgemäßen Vorrichtung ist am Kopf und am anderen Ende der Elektrode jeweils ein Abstandshalter mit einer um den Faktor > 1 größeren Fläche als jeweils derjenigen der (des) Abstandhalters(s) innerhalb des Elektrodenbereiches, jedoch kleineren Fläche, als dem kleinsten zu durchfahrenden Querschnitt des Leitungssystems entspricht, vorgesehen.In an advantageous embodiment of the device according to the invention, there is a spacer at the head and at the other end of the electrode with an area that is greater by a factor of> 1 than that of the spacer (s) within the electrode area, but smaller area than the smallest corresponds to the traversed cross section of the line system.

Durch die Elastizität der Elektroden ist eine Anpassung an gekrümmte Flächen möglich. Hierdurch ist eine Demontage der zu polierenden Rohre nicht mehr nötig, und es kann sowohl durch Krümmer und Schieber als auch in geneigten Leitungen gearbeitet werden. Dadurch, daß die Elektrode als Zugdraht ausgebildet ist, ist es möglich, die Rohre fernbedient zu elektropolieren, wodurch die Strahlenbelastung des Personals wesentlich verringert werden kann. Eine Stromstärke zwischen 300 und 400 Ampere reicht in den meisten Fällen aus.Due to the elasticity of the electrodes, an adaptation to curved surfaces is possible. As a result, disassembly of the pipes to be polished is no longer necessary, and it is possible to work with elbows and sliders as well as in inclined lines. The fact that the electrode is designed as a pull wire, it is possible to electropolish the tubes remotely, whereby the radiation exposure of the personnel can be significantly reduced. A current between 300 and 400 amperes is sufficient in most cases.

Im folgenden wird die Erfindung anhand eines Durchführungsbeispieles und anhand der Zeichnungen (Figuren 1 und 2) erläutert:

  • Figur 1 zeigt die erfindungsgemäße Vorrichtung mit einer Elektrode 4 in der Form eines spiralförmigen Edelstahldrahtes, der mit einem als Stromzuleitung dienenden Kupfer-Zugdraht (nicht dargestellt) verbunden ist. Mehrere Abstandshalter 5 und 6 vermeiden einen ungewollten Kontakt der Elektrode mit der Innenwand 2 des Rohres 1 .
The invention is explained below using an exemplary embodiment and the drawings (FIGS. 1 and 2):
  • FIG. 1 shows the device according to the invention with an electrode 4 in the form of a spiral stainless steel wire, which is connected to a copper pull wire (not shown) serving as a power supply line. Several spacers 5 and 6 prevent unwanted contact of the electrode with the inner wall 2 of the tube 1.

In Figur 2 ist eine andere Ausbildung der erfindungsgemäßen Vorrichtung aufgeführt, in welcher die Elektrode 4 a in Form eines gewendelten Edelstahlbandes ausgebildet ist.Another embodiment of the device according to the invention is shown in FIG. 2, in which the electrode 4 a is designed in the form of a coiled stainless steel strip.

Durch Wendeln eines 10 x 1 mm starken VA-Bandes wurde eine ca. 300 mm lange Elektrode 4a hergestellt, die mit Abstandshalterungen 5 und 6 aus Teflon bestückt wurde. Damit konnte ein mit radioaktiven Verunreinigungen kontaminiertes Leitungssystem 1 aus Edelstahl, bestehend aus 3x1 m langen Rohren, 0 100 mm, 2 Bögen und 1 Kugelhahn innenseitig durch Elektropolieren von seiner radioaktiven Kontamination befreit werden. Das Leitungssystem 1 wurde in einer großen Wanne, die mit einem Elektrolyten aus Phosphor-und Schwefelsäure gefüllt war, gelegt und die Elektrode 4a wurde mit einer Geschwindigkeit von 5 cm/min durchgezogen. Es wurde Gleichstrom von 10-20 A/dm2 verwendet. Auf diese Art war es möglich, einen Dekontaminationsfaktor von ca. 500 zu erreichen.By turning a 10 x 1 mm thick VA tape, an approximately 300 mm long electrode 4a was produced, which was fitted with spacers 5 and 6 made of Teflon. So that one with radioactive contamination Contaminated pipe system 1 made of stainless steel, consisting of 3x1 m long pipes, 0 100 mm, 2 elbows and 1 ball valve on the inside can be freed of its radioactive contamination by electropolishing. The line system 1 was placed in a large tub which was filled with an electrolyte of phosphoric and sulfuric acid, and the electrode 4a was pulled through at a speed of 5 cm / min. Direct current of 10-20 A / dm 2 was used. In this way it was possible to achieve a decontamination factor of around 500.

Claims (3)

1. Verfahren zur Reinigung der Innenwände von metallischen Leitungssystemen durch Elektropolieren mit Hilfe bewegter Elektroden,
dadurch gekennzeichnet,
daß man den Elektrolyten in den zu reinigenden Abschnitt des Leitungssystemes einfüllt und die Elektrolyse mit Hilfe einer elastischen, aus spiralförmigem -Draht oder aus gewendel- tem Band bestehenden Elektrode durchführt.1. Process for cleaning the inner walls of metallic pipe systems by electropolishing with the help of moving electrodes
characterized,
that fills the electrolyte in the cleaned portion of the line system and the electrolysis using performs an elastic, consisting of spiral -wire or gewendel- t em band electrode. 2. Vorrichtung zur Durchführung des Verfahrens nach Anspruch 1,
gekennzeichnet durch
eine elastische, aus einem spiralförmigen Draht oder einem gewendelten Band bestehende Elektrode (4, 4a) sowie durch mehrere, zumindest im Elektrodenbereich fest oder verschiebbar auf der Elektrode angeordnete, isolierende Abstandshalter (5, 6).2. Device for carrying out the method according to claim 1,
marked by
an elastic electrode (4, 4a) consisting of a spiral wire or a coiled band, and by means of a plurality of insulating spacers (5, 6) which are fixed or displaceable on the electrode, at least in the electrode area. 3. Vorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß am Kopf und am anderen Ende der Elektrode (4, 4a) jeweils ein Abstandshalter (5) mit einer um den Faktor größer als 1 größeren Fläche als jeweils derjenigen der (des) Abstandshalter(s) (6) innerhalb des Elektrodenbereiches, jedoch kleineren Fläche, als dem kleinsten zu durchfahrenden Querschnitt des Leitungssystems (1) entspricht, vorgesehen ist.3. Apparatus according to claim 2, characterized in that at the head and at the other end of the electrode (4, 4a) each have a spacer (5) with a larger by a factor of greater than 1 area than that of the (the) spacer (s ) (6) within the electrode area, but smaller area than the smallest cross section of the line system (1) to be traversed, is provided.
EP82104946A 1981-09-12 1982-06-05 Apparatus for cleaning the inner walls of metallic tubular systems by electropolishing by means of moving electrodes Expired EP0074464B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19813136186 DE3136186A1 (en) 1981-09-12 1981-09-12 METHOD AND DEVICE FOR CLEANING THE INTERNAL WALL OF METAL PIPING SYSTEMS BY ELECTROPOLISHING WITH ELECTRODES MOVED
DE3136186 1981-09-12

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Publication Number Publication Date
EP0074464A1 true EP0074464A1 (en) 1983-03-23
EP0074464B1 EP0074464B1 (en) 1985-08-07

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EP82104946A Expired EP0074464B1 (en) 1981-09-12 1982-06-05 Apparatus for cleaning the inner walls of metallic tubular systems by electropolishing by means of moving electrodes

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JP (1) JPS5855599A (en)
DE (1) DE3136186A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4645581A (en) * 1984-08-17 1987-02-24 Kraftwerk Union Aktiengesellschaft Apparatus for electropolishing the inner surface of U-shaped heat exchanger tubes
WO2017036561A1 (en) * 2015-09-04 2017-03-09 Poligrat Gmbh Electrode device for electrochemical workpiece machining
CN113089073A (en) * 2021-03-30 2021-07-09 中国工程物理研究院机械制造工艺研究所 Flexible electrode for electrochemical polishing and electrochemical polishing method for inner cavity structure

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6483697A (en) * 1987-09-28 1989-03-29 Oe Kogyo Kk Method for electropolishing inner surface of straight tube or bent tube with coiled electrode

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1931174A1 (en) * 1969-06-19 1971-01-07 Siemens Ag Device for the electrolytic polishing of nuclear fuel rod cladding tubes
DE2435277B1 (en) * 1974-07-23 1975-04-10 Langbein-Pfanhauser Werke Ag, 4040 Neuss Anode for the galvanic treatment of a hollow profile
DE2146794B2 (en) * 1971-09-18 1976-08-05 Siemens AG, 1000 Berlin und 8000 München METHOD AND DEVICE FOR ANODIC POLISHING OF NOBLE PARTS
DE2313026B2 (en) * 1973-03-15 1977-03-03 Siemens AG, 1000 Berlin und 8000 München METHOD OF ANODIC POLISHING THE INNER SURFACE OF A NOBULAR BODY

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1209242A (en) * 1958-07-09 1960-02-29 Jacquet Hispano Suiza Improvements to processes and apparatus for electrolytic treatment of tubes, more specifically for polishing
CH396561A (en) * 1960-10-06 1965-07-31 Nyby Bruk Ab Process for the electrolytic polishing of surfaces of metallic objects

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1931174A1 (en) * 1969-06-19 1971-01-07 Siemens Ag Device for the electrolytic polishing of nuclear fuel rod cladding tubes
DE2146794B2 (en) * 1971-09-18 1976-08-05 Siemens AG, 1000 Berlin und 8000 München METHOD AND DEVICE FOR ANODIC POLISHING OF NOBLE PARTS
DE2313026B2 (en) * 1973-03-15 1977-03-03 Siemens AG, 1000 Berlin und 8000 München METHOD OF ANODIC POLISHING THE INNER SURFACE OF A NOBULAR BODY
DE2435277B1 (en) * 1974-07-23 1975-04-10 Langbein-Pfanhauser Werke Ag, 4040 Neuss Anode for the galvanic treatment of a hollow profile

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4645581A (en) * 1984-08-17 1987-02-24 Kraftwerk Union Aktiengesellschaft Apparatus for electropolishing the inner surface of U-shaped heat exchanger tubes
WO2017036561A1 (en) * 2015-09-04 2017-03-09 Poligrat Gmbh Electrode device for electrochemical workpiece machining
CN113089073A (en) * 2021-03-30 2021-07-09 中国工程物理研究院机械制造工艺研究所 Flexible electrode for electrochemical polishing and electrochemical polishing method for inner cavity structure

Also Published As

Publication number Publication date
JPS5855599A (en) 1983-04-01
EP0074464B1 (en) 1985-08-07
DE3136186C3 (en) 1985-03-07
DE3136186A1 (en) 1983-03-24

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