EP0247209A1 - Apparatus and process for electrochemically polishing the inner surfaces of pipes - Google Patents

Apparatus and process for electrochemically polishing the inner surfaces of pipes Download PDF

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Publication number
EP0247209A1
EP0247209A1 EP86106812A EP86106812A EP0247209A1 EP 0247209 A1 EP0247209 A1 EP 0247209A1 EP 86106812 A EP86106812 A EP 86106812A EP 86106812 A EP86106812 A EP 86106812A EP 0247209 A1 EP0247209 A1 EP 0247209A1
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EP
European Patent Office
Prior art keywords
electrolyte
polishing head
tube
dielectric
cathode
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EP86106812A
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German (de)
French (fr)
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EP0247209B1 (en
Inventor
Jürgen Menzel
Georg Dr. Henkel
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Poligrat GmbH
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Poligrat GmbH
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Priority to AT86106812T priority Critical patent/ATE54681T1/en
Priority to DE8686106812T priority patent/DE3672831D1/en
Priority to EP86106812A priority patent/EP0247209B1/en
Priority to US07/047,653 priority patent/US4772367A/en
Priority to JP62120323A priority patent/JPH0765240B2/en
Publication of EP0247209A1 publication Critical patent/EP0247209A1/en
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F7/00—Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects; Servicing or operating
    • 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 device for electrochemical polishing and / or pickling the inner surfaces of pipes with a flowing electrolyte which at least partially passes through a cathode arranged inside the anodically connected pipe, and to a corresponding method for electrochemical polishing and / or pickling pipe inner surfaces .
  • a method and a device for electrochemically polishing the inner walls of pipes are also known from European patent application 82 104 946.7, in which an electrode acting as a cathode can be moved through the pipe. The electrolyte is filled into the entire pipe section to be electropolished.
  • a device for electropolishing the inner walls of pipes in which a pipe lance is introduced into the pipe, which has a cathodic area between its tip and a retaining ring, the pipe lance with bores for the passage of the electrolyte liquid is provided.
  • the known methods and devices for electrochemical polishing and / or pickling of inner tube surfaces have the disadvantage that a very high consumption of electrolyte is required for complete filling, flushing and cooling of the tube.
  • the gases (hydrogen and oxygen) generated during electrolytic polishing also have to be removed, which likewise results in a very high electrolyte throughput through the tube.
  • the invention has for its object to provide a device and a method for electrochemical polishing and / or pickling the inner surfaces of pipes, which enables both a reduction in the amount of electrolyte used and an improvement in the polishing and pickling quality. It is also intended by the invention that a considerably greater variety of electrolyte compositions can be used compared to conventional processes.
  • the device according to the invention for solving this problem is characterized by a polishing head which is movable through the tube and has feed lines for the electrolyte and for electric current, a cathode arranged in the interior of the polishing head and a dielectric which at least partially forms the outer wall of the polishing head, the passes the electrolyte stream and leaves a working gap for the electrolyte stream between itself and the pipe inner surface to be polished or to be etched.
  • the method according to the invention for solving the problem is characterized in that the electrolyte stream is pumped into a polishing head provided with a cathode and out of it by a dielectric into a working gap formed between the dielectric and the inner surface of the tube.
  • a polishing head is thus moved through the tube. It is essential that a so-called working gap is formed between a wall of the polishing head formed from a dielectric and the inner surface of the tube, into which the electrolyte is pressed by the dielectric.
  • the inventive design of a working gap between the dielectric and the inner surface of the tube significantly reduces the consumption of electrolyte compared to the prior art.
  • Electrolytes that can be regenerated via ion exchangers or electrolytic separation cells can be used. It is possible to keep the metal content of the electrolyte so low that the cathode surfaces cannot be passivated by deposited metal sludge.
  • the stream of electrolyte flowing into the polishing head into one anodic partial flow and a cathodic partial flow is divided, the anodic partial flow passing through the dielectric and the tube inner surface, but not the cathode, while the cathodic partial flow passes the cathode but not the tube inner surface.
  • the polishing head (12) is slowly moved through the tube 10.
  • the polishing head 12 is sometimes also referred to as a "tampon".
  • the polishing head 12 is moved through the tube 10 by means of a guide 14, which is designed as a tube with a much smaller diameter than the tube 10 to be cleaned.
  • the polishing head 12 is approximately cylindrical and lies concentrically in the pipe 10 to be cleaned.
  • the jacket of the cylindrical polishing head 12 is formed by a dielectric 18 which is uniformly spaced from the inner surface 16 of the tube 10.
  • the polishing head 12 can be moved in the direction of the arrow 20, that is to say in both directions, through the tube 10.
  • the electrolyte flow 22 in FIGS. 1 and 2 enters the polishing head 12 from the right through the guide 14 and in the exemplary embodiment according to FIG. 1 is pressed radially outwards by the dielectric 18 according to the arrows.
  • the guide 14 receives the electrical supply lines 25 for the cathodes 26.
  • a uniform, narrow working gap 28 is formed between the cylindrical jacket-shaped dielectric outer walls of the polishing head 12 and the inner surface 16 of the tube 10.
  • the electrolyte stream 22 ⁇ passes through the working gap 28 and causes the electrochemical removal and polishing in a known manner on the inner surface 16.
  • the electrolyte stream 22 entering the polishing head 12 is divided into a cathodic and an anodic partial stream 30 or 32.
  • the cathodic partial stream 30 only passes through the cathodes 26, but not through the dielectric 18 and the working gap 28.
  • the hydrogen gas formed on the cathodes 26 does not reach the dielectric 18 or the inner surface 16 to be polished, which on the one hand prevents the dielectric 18 from being loaded with hydrogen gas and on the other hand also avoids harmful effects of the hydrogen on the inner surface 16.
  • the anodic partial stream 32 passes through the dielectric wall 18 and the working gap 28, so that the electrochemical polishing of the inner surface 16 can take place.
  • the cathodic partial stream 30 exits through an opening 34 in the front wall of the polishing head 12 and, like the anodic partial stream 32, is collected and, if necessary, returned after regeneration.
  • Textile Teflon fabrics are preferably used as the dielectric 18. Glass fiber fabrics and acid-resistant plastic fabrics and nonwovens can also be used.
  • the dimensions of the polishing head 12 and, in particular, of the dielectric 18 are adapted or selected for a given tube inner diameter in such a way that a working gap with optimal thickness is created.

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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)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)

Abstract

Eine Vorrichtung und ein Verfahren zum elektrochemischen Polieren und/oder Beizen von Rohr-Innenflächen (16) sehen vor, daß ein Polierkopf (12) durch das Rohr bewegt wird. Der Polierkopf (12) weist eine dielektrische Außenwand auf, die zwischen sich und der zu reinigenden Innenfläche 16 des Rohres einen engen Arbeitsspalt 28 bildet, durch den der Elektrolyt strömt. Hierdurch ist bei geringem Elektrolytverbrauch eine qualitativ hochwertige und elektrochemische Politur der Rohr-Innenfläche ermöglicht. Der Elektrolytstrom kann in einen kathodischen und einen anodischen Teilstrom (30 bzw. 32) aufgeteilt sein.A device and a method for the electrochemical polishing and / or pickling of inner pipe surfaces (16) provide that a polishing head (12) is moved through the pipe. The polishing head (12) has a dielectric outer wall, which forms a narrow working gap 28 between it and the inner surface 16 of the tube to be cleaned, through which the electrolyte flows. This enables high-quality and electrochemical polishing of the inner surface of the pipe with low electrolyte consumption. The electrolyte stream can be divided into a cathodic and an anodic partial stream (30 or 32).

Description

Die Erfindung betrifft eine Vorrichtung zum elektrochemischen Polieren und/oder Beizen der Innenflächen von Rohren mit einem strömenden Elektrolyt, der zumindest teilweise eine im Inneren des anodisch geschalteten Rohres angeordnete Kathode passiert, sowie ein entsprechendes Verfahren zum elektrochemischen Polie­ren und/oder Beizen von Rohr-Innenflächen.The invention relates to a device for electrochemical polishing and / or pickling the inner surfaces of pipes with a flowing electrolyte which at least partially passes through a cathode arranged inside the anodically connected pipe, and to a corresponding method for electrochemical polishing and / or pickling pipe inner surfaces .

Aus der europäischen Patentanmeldung 82 104 945.9 sind ein Ver­fahren und eine Vorrichtung zum sogenannten Elektropolieren der Innenwände von metallischen Rohren bekannt, bei denen der Elek­trolyt mittels Hochdruck von ca. 50 Bar auf ein Teilstück der Wandung des Rohres aufgebracht wird. Die Kathode wird mit Hilfe des Hochdruckstrahls im Rohr bewegt, so daß nacheinander unter­schiedliche Abschnitte der Rohr-Innenwand poliert werden können.From European patent application 82 104 945.9 a method and a device for the so-called electropolishing of the inner walls of metallic pipes are known, in which the electrolyte is applied to a section of the wall of the pipe by means of high pressure of approximately 50 bar. The cathode is moved in the tube with the aid of the high-pressure jet, so that different sections of the tube inner wall can be polished in succession.

Aus der europäischen Patentanmeldung 82 104 946.7 sind eben­falls ein Verfahren und eine Vorrichtung zum elektrochemischen Polieren der Innenwände von Rohren bekannt, bei denen eine als Kathode wirkende Elektrode durch das Rohr bewegbar ist. Der Elektrolyt wird in den gesamten zu elektropolierenden Rohrab­schnitt eingefüllt.A method and a device for electrochemically polishing the inner walls of pipes are also known from European patent application 82 104 946.7, in which an electrode acting as a cathode can be moved through the pipe. The electrolyte is filled into the entire pipe section to be electropolished.

Aus dem DE-GM 80 11 918 ist eine Vorrichtung zum Elektropolie­ren der Innenwände von Rohren bekannt, bei der eine Rohrlanze in das Rohr eingebracht wird, die zwischen ihrer Spitze und einem Stauring einen kathodischen Bereich aufweist, wobei die Rohrlanze mit Bohrungen zum Durchtritt der Elektrolytflüssig­keit versehen ist.From DE-GM 80 11 918 a device for electropolishing the inner walls of pipes is known, in which a pipe lance is introduced into the pipe, which has a cathodic area between its tip and a retaining ring, the pipe lance with bores for the passage of the electrolyte liquid is provided.

Der vorstehend beispielhaft angedeutete Stand der Technik für das elektrochemische Polieren von Rohr-Innenwänden läßt sich grob in zwei Klassen aufteilen:

  • 1) In das innenseitig zu polierende Rohr wird eine durchge­hende Kathode eingesetzt und der Elektrolyt wird durch das anodisch geschaltete Rohr gepumpt. Während des Elektropo­lierens liegt das Rohr entweder waagerecht oder leicht schräg und wird um seine Längsachse gedreht. Es ist dabei auch möglich, das Rohr vertikal zu stellen.
  • 2) Es wird eine nur partiell auf jeweils einen bestimmten Ab­schnitt der Rohr-Innenwand einwirkende Kathode (die also wesentlich kürzer ist als das zu elektropolierende Rohr) durch das Rohr bewegt. Dabei wird der Elektrolyt durch das Rohr gepumpt.
The state of the art for the electrochemical polishing of inner pipe walls, which is indicated by way of example, can be roughly divided into two classes:
  • 1) A continuous cathode is inserted into the tube to be polished on the inside and the electrolyte is pumped through the anodically connected tube. During electropolishing, the tube is either horizontal or slightly oblique and is rotated about its longitudinal axis. It is also possible to place the pipe vertically.
  • 2) A cathode (which is therefore considerably shorter than the tube to be electropolished) which only partially acts on a particular section of the tube inner wall is moved through the tube. The electrolyte is pumped through the tube.

Die bekannten Verfahren und Vorrichtungen zum elektrochemischen Polieren und/oder Beizen von Rohr-Innenflächen haben den Nach­teil, daß zur vollständigen Füllung, Durchspülung und Kühlung des Rohres ein sehr hoher Elektrolytverbrauch erforderlich ist. Auch müssen die bei der elektrolytischen Polierung entstehenden Gase (Wasserstoff und Sauerstoff) abgeführt werden, was eben­falls einen sehr hohen Elektrolyt-Durchsatz durch das Rohr be­dingt.The known methods and devices for electrochemical polishing and / or pickling of inner tube surfaces have the disadvantage that a very high consumption of electrolyte is required for complete filling, flushing and cooling of the tube. The gases (hydrogen and oxygen) generated during electrolytic polishing also have to be removed, which likewise results in a very high electrolyte throughput through the tube.

Auch können bei den bekannten Vorrichtungen und Verfahren nur Elektrolyte eingesetzt werden, deren Metallgehalt erheblichen Einschränkungen unterworfen ist. Ein erhöhter Metallgehalt in den Elektrolyten führt bei den bekannten Vorrichtungen nämlich zur Passivierung der Kathodenoberflächen durch Belegung mit kathodisch abgeschiedenem Metallschlamm, was eine erhebliche Reduzierung der Polierqualität zur Folge hat. Um den Metallge­halt der Elektrolyte gering zu halten, ist es deshalb erforder­lich, den Elektrolyte in erheblichen Mengen umzuwälzen.Also, only known electrolytes can be used in the known devices and methods, the metal content of which is subject to considerable restrictions. An increased metal content in In the known devices, the electrolyte leads to the passivation of the cathode surfaces by covering them with cathodically deposited metal sludge, which results in a considerable reduction in the polishing quality. In order to keep the metal content of the electrolytes low, it is therefore necessary to circulate the electrolytes in considerable quantities.

Auch ist zu berücksichtigen, daß die Beseitigung des mit Metal­len angereicherten Elektrolyts zur Vermeidung von Umweltbela­stungen sehr große Kosten verursacht. Beim Stand der Technik werden zum Elektropolieren der Innenflächen von Rohren aus au­stenitischen Chromnickelstählen Gemische aus Phosphorsäure, Schwefelsäure und Wasser verwendet. Diese Säuren stellen schon als solche eine erhebliche Umweltbelastung und ein Gefährdungs­potential dar, das besondere Sicherheitsmaßnahmen erforderlich macht.It must also be taken into account that the removal of the electrolyte enriched with metals in order to avoid environmental pollution causes very great costs. In the prior art, mixtures of phosphoric acid, sulfuric acid and water are used for electropolishing the inner surfaces of pipes made of austenitic chromium-nickel steels. As such, these acids already represent a considerable environmental pollution and a hazard potential that requires special safety measures.

Der Erfindung liegt die Aufgabe zugrunde, eine Vorrichtung und ein Verfahren zum elektrochemischen Polieren und/oder Beizen der Innenflächen von Rohren zu schaffen, die bzw. das sowohl eine Reduzierung der verwendeten Elektrolytmenge als auch eine Verbesserung der Polier- und Beizqualität ermöglicht. Auch soll durch die Erfindung erreicht werden, daß gegenüber herkömmli­chen Verfahren eine wesentlich größere Vielfalt von Elektrolyt-­Zusammensetzungen verwendet werden kann.The invention has for its object to provide a device and a method for electrochemical polishing and / or pickling the inner surfaces of pipes, which enables both a reduction in the amount of electrolyte used and an improvement in the polishing and pickling quality. It is also intended by the invention that a considerably greater variety of electrolyte compositions can be used compared to conventional processes.

Die erfindungsgemäße Vorrichtung zur Lösung dieser Aufgabe zeichnet sich aus durch einen Polierkopf, der durch das Rohr bewegbar ist und Zuleitungen für den Elektrolyt und für elek­trischen Strom aufweist, eine im Inneren des Polierkopfes ange­ordnete Kathode und ein zumindest teilweise die Außenwand des Polierkopfes bildendes Dielektrikum, das den Elektrolytstrom durchläßt und zwischen sich und der zu polierenden bzw. zu bei­zenden Rohr-Innenfläche einen Arbeitsspalt für den Elektrolyt­strom freiläßt.The device according to the invention for solving this problem is characterized by a polishing head which is movable through the tube and has feed lines for the electrolyte and for electric current, a cathode arranged in the interior of the polishing head and a dielectric which at least partially forms the outer wall of the polishing head, the passes the electrolyte stream and leaves a working gap for the electrolyte stream between itself and the pipe inner surface to be polished or to be etched.

Das erfindungsgemäße Verfahren zur Lösung der gestellten Auf­gabe zeichnet sich dadurch aus, daß der Elektrolytstrom in einen mit einer Kathode versehenen Polierkopf und aus diesem durch ein Dielektrikum in einen zwischen dem Dielektrikum und der Rohr-Innenfläche gebildeten Arbeitsspalt gepumpt wird.The method according to the invention for solving the problem is characterized in that the electrolyte stream is pumped into a polishing head provided with a cathode and out of it by a dielectric into a working gap formed between the dielectric and the inner surface of the tube.

Gemäß der Erfindung wird also ein Polierkopf durch das Rohr be­wegt. Wesentlich ist, daß zwischen einer aus einem Dielektrikum gebildeten Wand des Polierkopfes und der Innenfläche des Rohres ein sogenannter Arbeitsspalt gebildet wird, in welchen der Elektrolyt durch das Dielektrikum eingepreßt wird.According to the invention, a polishing head is thus moved through the tube. It is essential that a so-called working gap is formed between a wall of the polishing head formed from a dielectric and the inner surface of the tube, into which the electrolyte is pressed by the dielectric.

Durch die erfindungsgemäß vorgesehene Ausbildung eines Arbeits­spalts zwischen dem Dielektrikum und der Innenfläche des Rohres wird der Elektrolytverbrauch im Vergleich zum Stand der Technik erheblich gesenkt.The inventive design of a working gap between the dielectric and the inner surface of the tube significantly reduces the consumption of electrolyte compared to the prior art.

Es hat sich auch gezeigt, daß durch die Kombination von elek­trochemischem Polieren mit dem Wischeffekt des Dielektrikums die Wirksamkeit des Elektropoliervorgangs in einer nach her­kömmlichen Verfahren nicht zu erzielende Weise die Polierquali­tät erheblich verbessert werden kann. Auch können mit Erfolg sehr unterschiedliche Elektrolyte verwendet werden, die im Ver­gleich zum Stand der Technik insbesondere eine wesentlich geringere Umweltbelastung darstellen. Es können Elektrolyte eingesetzt werden, die über Ionenaustauscher oder elektrolyti­sche Abscheidezellen regenerierbar sind. Dabei ist es möglich, den Metallgehalt des Elektrolyten so niedrig zu halten, daß die Kathodenoberflächen nicht durch abgeschiedene Metallschlämme passiviert werden können.It has also been shown that by combining electrochemical polishing with the wiping effect of the dielectric, the effectiveness of the electropolishing process can be significantly improved in a manner which cannot be achieved by conventional methods. Very different electrolytes can also be used with success, which in particular represent a significantly lower environmental impact compared to the prior art. Electrolytes that can be regenerated via ion exchangers or electrolytic separation cells can be used. It is possible to keep the metal content of the electrolyte so low that the cathode surfaces cannot be passivated by deposited metal sludge.

In einer bevorzugten Variante der Erfindung ist vorgesehen, daß der in den Polierkopf einströmende Elektrolytstrom in einen anodischen Teilstrom und einen kathodischen Teilstrom aufge­teilt ist, wobei der anodische Teilstrom das Dielektrikum und die Rohr-Innenfläche, aber nicht die Kathode passiert, während der kathodische Teilstrom die Kathode, aber nicht die Rohr-In­nenfläche passiert.In a preferred variant of the invention it is provided that the stream of electrolyte flowing into the polishing head into one anodic partial flow and a cathodic partial flow is divided, the anodic partial flow passing through the dielectric and the tube inner surface, but not the cathode, while the cathodic partial flow passes the cathode but not the tube inner surface.

Eine derartige Auftrennung des Elektrolytstromes in anodische und kathodische Teilströme ist aus der nicht vorveröffentlich­ten europäischen Patentanmeldung 86 105 747 der Anmelderin beim partiellen elektrochemischen Polieren von freien Oberflächen bekannt. Alle dort erwähnten Vorteile gelten auch für das Innenpolieren von Rohren.Such a separation of the electrolyte stream into anodic and cathodic partial streams is known from the not previously published European patent application 86 105 747 by the applicant for the partial electrochemical polishing of free surfaces. All the advantages mentioned there also apply to the internal polishing of pipes.

Weitere Vorteile der Erfindung ergeben sich aus den Unteran­sprüchen.Further advantages of the invention emerge from the subclaims.

Nachfolgend werden Ausführungsbeispiele der Erfindung anhand der Zeichnung näher erläutert. Es zeigt:

  • Fig. 1 einen Schnitt durch den Teil eines Rohres, dessen Innen­fläche poliert werden soll, sowie einen im Rohr bewegba­ren Polierkopf und
  • Fig. 2 einen Schnitt gemäß Fig. 1 mit einem Polierkopf, in dem der Elektrolytstrom in einen anodischen und einen kathodischen Teilstrom getrennt wird.
Exemplary embodiments of the invention are explained in more detail below with reference to the drawing. It shows:
  • Fig. 1 shows a section through the part of a tube whose inner surface is to be polished, and a polishing head movable in the tube and
  • FIG. 2 shows a section according to FIG. 1 with a polishing head in which the electrolyte flow is separated into an anodic and a cathodic partial flow.

Ein Rohr 10 aus Stahl, beispielsweise Chromnickelstahl, soll innenseitig gereinigt und poliert werden. Hierzu wird der Po­lierkopf (12) langsam durch das Rohr 10 bewegt. Der Polierkopf 12 wird mitunter auch als "Tampon" bezeichnet. Mittels einer Führung 14, die als Rohr mit wesentlich geringerem Durchmesser als das zu reinigende Rohr 10 ausgebildet ist, wird der Polier­kopf 12 durch das Rohr 10 bewegt.A pipe 10 made of steel, for example chromium-nickel steel, is to be cleaned and polished on the inside. For this purpose, the polishing head (12) is slowly moved through the tube 10. The polishing head 12 is sometimes also referred to as a "tampon". The polishing head 12 is moved through the tube 10 by means of a guide 14, which is designed as a tube with a much smaller diameter than the tube 10 to be cleaned.

Wie den Fig. 1 und 2 zu entnehmen ist, ist der Polierkopf 12 etwa zylinderförmig ausgebildet und liegt konzentrisch in dem zu reinigenden Rohr 10.As can be seen from FIGS. 1 and 2, the polishing head 12 is approximately cylindrical and lies concentrically in the pipe 10 to be cleaned.

Der Mantel des zylinderförmigen Polierkopfes 12 wird durch ein Dielektrikum 18 gebildet, das durchgehend einen gleichmäßigen Abstand zur Innenfläche 16 des Rohres 10 aufweist.The jacket of the cylindrical polishing head 12 is formed by a dielectric 18 which is uniformly spaced from the inner surface 16 of the tube 10.

Der Polierkopf 12 ist in Richtung des Pfeiles 20, also in bei­den Richtungen durch das Rohr 10 bewegbar.The polishing head 12 can be moved in the direction of the arrow 20, that is to say in both directions, through the tube 10.

Der Elektrolytstrom 22 tritt in den Fig. 1 und 2 durch die Füh­rung 14 von rechts in den Polierkopf 12 ein und wird beim Aus­führungsbeispiel gemäß Fig. 1 durch das Dielektrikum 18 gemäß den Pfeilen radial nach außen gepreßt.The electrolyte flow 22 in FIGS. 1 and 2 enters the polishing head 12 from the right through the guide 14 and in the exemplary embodiment according to FIG. 1 is pressed radially outwards by the dielectric 18 according to the arrows.

Die Führung 14 nimmt bei beiden Ausführungsbeispielen gemäß den Fig. 1 und 2 jeweils die elektrischen Versorgungsleitungen 25 für die Kathoden 26 auf.In both exemplary embodiments according to FIGS. 1 and 2, the guide 14 receives the electrical supply lines 25 for the cathodes 26.

Zwischen den zylindermantelförmigen dielektrischen Außenwänden des Polierkopfes 12 und der Innenfläche 16 des Rohres 10 wird ein gleichförmiger enger Arbeitsspalt 28 gebildet. Der Elektro­lytstrom 22ʹ passiert den Arbeitsspalt 28 und bewirkt in be­kannter Weise an der Innenfläche 16 die elektrochemische Abtra­gung und Politur.A uniform, narrow working gap 28 is formed between the cylindrical jacket-shaped dielectric outer walls of the polishing head 12 and the inner surface 16 of the tube 10. The electrolyte stream 22ʹ passes through the working gap 28 and causes the electrochemical removal and polishing in a known manner on the inner surface 16.

Beim in Fig. 2 gezeigten Ausführungsbeispiel wird der in den Polierkopf 12 eintretende Elektrolytstrom 22 in einen kathodi­schen und einen anodischen Teilstrom 30 bzw. 32 aufgeteilt. Der kathodische Teilstrom 30 passiert nur die Kathoden 26, nicht aber das Dielektrikum 18 und den Arbeitsspalt 28. Somit gelangt das an den Kathoden 26 gebildete Wasserstoffgas nicht zum Di­elektrikum 18 und auch nicht zur zu polierenden Innenfläche 16, wodurch zum einen verhindert ist, daß das Dielektrikum 18 mit Wasserstoffgas belastet wird und zum anderen auch schädliche Wirkungen des Wasserstoffs an der Innenfläche 16 vermieden sind.In the exemplary embodiment shown in FIG. 2, the electrolyte stream 22 entering the polishing head 12 is divided into a cathodic and an anodic partial stream 30 or 32. The cathodic partial stream 30 only passes through the cathodes 26, but not through the dielectric 18 and the working gap 28. Thus, the hydrogen gas formed on the cathodes 26 does not reach the dielectric 18 or the inner surface 16 to be polished, which on the one hand prevents the dielectric 18 from being loaded with hydrogen gas and on the other hand also avoids harmful effects of the hydrogen on the inner surface 16.

Der anodische Teilstrom 32 passiert gemäß Fig. 2 die dielektri­sche Wand 18 und den Arbeitsspalt 28, so daß die elektrochemi­sche Politur der Innenfläche 16 erfolgen kann.According to FIG. 2, the anodic partial stream 32 passes through the dielectric wall 18 and the working gap 28, so that the electrochemical polishing of the inner surface 16 can take place.

Der kathodische Teilstrom 30 tritt durch eine Öffnugn 34 in der Vorderwand des Polierkopfes 12 aus und wird ebenso wie der ano­dische Teilstrom 32 aufgefangen und nach einer Regenerierung gegebenenfalls zurückgeführt.The cathodic partial stream 30 exits through an opening 34 in the front wall of the polishing head 12 and, like the anodic partial stream 32, is collected and, if necessary, returned after regeneration.

Als Dielektrikum 18 werden bevorzugt textile Teflongewebe ver­wendet. Auch können Glasfasergewebe und säurebeständige Kunst­stoffgewebe und -vliese eingesetzt werden.Textile Teflon fabrics are preferably used as the dielectric 18. Glass fiber fabrics and acid-resistant plastic fabrics and nonwovens can also be used.

Die Abmessungen des Polierkopfes 12 und insbesondere des Di­elektrikums 18 werden bei einem gegebenen Rohr-Innendurchmesser so angepaßt oder gewählt, daß ein Arbeitsspalt mit optimaler Stärke entsteht.The dimensions of the polishing head 12 and, in particular, of the dielectric 18 are adapted or selected for a given tube inner diameter in such a way that a working gap with optimal thickness is created.

Claims (9)

1. Vorrichtung zum elektrochemischen Polieren und/oder Beizen der Innenflächen (16) von Rohren (10) mit einem strömen­den Elektrolyt (22), der zumindest teilweise eine im Inneren des anodisch geschalteten Rohres (10) angeordnete Kathode (26) passiert,
gekennzeichnet durch
- einen Polierkopf (12), der durch das Rohr (10) bewegbar ist und Zuleitungen (14; 25) für den Elektrolyt und für elektri­schen Strom aufweist,
- eine im Inneren des Polierkopfes (12) angeordnete Kathode (26) und
- ein zumindest teilweise die Außenwand des Polierkopfes (12) bildendes Dielektrikum (18), das Elektrolyt durchläßt und zwischen sich und der zu polierenden bzw. zu beizenden Rohr-­Innenfläche (16) einen Arbeitsspalt (28) für den Elektrolyt­strom (22ʹ, 32) freiläßt.1. Device for electrochemically polishing and / or pickling the inner surfaces (16) of tubes (10) with a flowing electrolyte (22) which at least partially passes through a cathode (26) arranged inside the anodically connected tube (10),
characterized by
a polishing head (12) which can be moved through the tube (10) and has feed lines (14; 25) for the electrolyte and for electric current,
- An inside of the polishing head (12) arranged cathode (26) and
- A dielectric (18), which at least partially forms the outer wall of the polishing head (12), passes the electrolyte and has a working gap (28) for the electrolyte flow (22ʹ, 32) between it and the pipe inner surface (16) to be polished or to be etched. releases. 2. Vorrichtung nach Anspruch 1,
dadurch gekennzeichnet,
daß der Polierkopf (12) zumindest annähernd zylinderförmig ist, wobei das Dielektrikum (18) zumindest teilweise den Mantel des Zylinders bildet.2. Device according to claim 1,
characterized by
that the polishing head (12) is at least approximately cylindrical, the dielectric (18) at least partially forming the jacket of the cylinder. 3. Vorrichtung nach einem der Ansprüche 1 oder 2,
dadurch gekennzeichnet,
daß der in den Polierkopf (12) einströmende Elektrolytstrom (22) in einen anodischen Teilstrom (32) und einen kathodischen Teilstrom (30) aufgeteilt wird, wobei der anodische Teilstrom das Dielektrikum (18) und die Rohr-Innenfläche (16), aber nicht die Kathode (26) passiert, während der kathodische Teilstrom (30) die Kathode (26), aber nicht die Rohr-Innenfläche (16) passiert.3. Device according to one of claims 1 or 2,
characterized by
that the electrolyte stream (22) flowing into the polishing head (12) into an anodic partial stream (32) and a cathodic one Partial stream (30) is divided, the anodic partial stream passing through the dielectric (18) and the inner tube surface (16), but not the cathode (26), while the cathodic partial stream (30) passes the cathode (26), but not the Pipe inner surface (16) happens. 4. Vorrichtung nach einem der Ansprüche 1 bis 3,
dadurch gekennzeichnet,
daß eine Führung (14) für den Polierkopf (12) als Rohr ausge­formt ist, in dem die elektrischen Leitungen (25) für den Po­lierkopf verlaufen und durch das der Elektrolyt zum Polierkopf gepumpt wird.4. Device according to one of claims 1 to 3,
characterized by
that a guide (14) for the polishing head (12) is formed as a tube in which the electrical lines (25) for the polishing head run and through which the electrolyte is pumped to the polishing head. 5. Vorrichtung nach einem der Anpsrüche 1 bis 3,
dadurch gekennzeichnet,
daß der Polierkopf (12) mittels einer elastischen Schlauchlei­tung mit Elektrolyt sowie Strom versorgt und mittels einer Stange oder eines Seiles durch das Rohr (10) gezogen wird.5. Device according to one of claims 1 to 3,
characterized by
that the polishing head (12) is supplied with electrolyte and electricity by means of an elastic hose line and is pulled through the tube (10) by means of a rod or a rope. 6. Vorrichtung nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet,
daß der Druck, mit dem der Elektrolyt durch das Dielektrikum (18) gedrückt wird, steuerbar ist.6. Device according to one of the preceding claims,
characterized by
that the pressure at which the electrolyte is pressed through the dielectric (18) is controllable. 7. Verfahren zum elektrochemischen Polieren und/oder Beizen von Rohr-Innenflächen (16), bei dem ein Elektrolyt die anodisch geschaltete Rohr-Innenfläche passiert,
dadurch gekennzeichnet,
daß der Elektrolytstrom (22) in einen mit einer Kathode (26) versehenen Polierkopf (12) und aus diesem durch ein Dielektri­kum (18) in einen zwischen dem Dielektrikum und der Rohr-Innen­fläche (16) gebildeten Arbeitsspalt (28) gepumpt wird.7. A method for the electrochemical polishing and / or pickling of inner pipe surfaces (16), in which an electrolyte passes through the anodically connected inner pipe surface,
characterized by
that the electrolyte stream (22) is pumped into a polishing head (12) provided with a cathode (26) and from there through a dielectric (18) into a working gap (28) formed between the dielectric and the inner tube surface (16). 8. Verfahren nach Anspruch 7,
dadurch gekennzeichnet,
daß der Elektrolytstrom (22) im Polierkopf (12) in einen anodi­schen Teilstrom (32) und in einen kathodischen Teilstrom (30) aufgeteilt wird, wobei der anodische Teilstrom das Dielektrikum (18) und die Rohr-Innenfläche (16), aber nicht die Kathode (26) passiert, während der kathodische Teilstrom (30) die Kathode (26), aber nicht das Dielektrikum und die Rohr-Innenfläche (16) passiert.8. The method according to claim 7,
characterized by
that the electrolyte stream (22) in the polishing head (12) into an anodic partial stream (32) and into a cathodic partial stream (30) is divided, the anodic partial stream passing through the dielectric (18) and the inner tube surface (16) but not the cathode (26), while the cathodic partial stream (30) passes through the cathode (26) but not the dielectric and the tube -Interior surface (16) happens. 9. Verfahren nach einem der Ansprüche 7 oder 8,
dadurch gekennzeichnet,
daß der Polierkopf (12) durch das Rohr (10) bewegt wird.9. The method according to any one of claims 7 or 8,
characterized by
that the polishing head (12) is moved through the tube (10).
EP86106812A 1986-05-20 1986-05-20 Apparatus and process for electrochemically polishing the inner surfaces of pipes Expired - Lifetime EP0247209B1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
AT86106812T ATE54681T1 (en) 1986-05-20 1986-05-20 APPARATUS AND METHOD FOR ELECTROCHEMICAL POLISHING THE INTERNAL SURFACE OF PIPES.
DE8686106812T DE3672831D1 (en) 1986-05-20 1986-05-20 DEVICE AND METHOD FOR ELECTROCHEMICALLY POLISHING THE INTERNAL SURFACES OF TUBES.
EP86106812A EP0247209B1 (en) 1986-05-20 1986-05-20 Apparatus and process for electrochemically polishing the inner surfaces of pipes
US07/047,653 US4772367A (en) 1986-05-20 1987-05-08 Apparatus for and a method of electrochemically polishing pipe inside surfaces
JP62120323A JPH0765240B2 (en) 1986-05-20 1987-05-19 Method and apparatus for electrochemically polishing and / or pickling the inner surface of a tube

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP86106812A EP0247209B1 (en) 1986-05-20 1986-05-20 Apparatus and process for electrochemically polishing the inner surfaces of pipes

Publications (2)

Publication Number Publication Date
EP0247209A1 true EP0247209A1 (en) 1987-12-02
EP0247209B1 EP0247209B1 (en) 1990-07-18

Family

ID=8195133

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86106812A Expired - Lifetime EP0247209B1 (en) 1986-05-20 1986-05-20 Apparatus and process for electrochemically polishing the inner surfaces of pipes

Country Status (5)

Country Link
US (1) US4772367A (en)
EP (1) EP0247209B1 (en)
JP (1) JPH0765240B2 (en)
AT (1) ATE54681T1 (en)
DE (1) DE3672831D1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0607894A1 (en) * 1993-01-19 1994-07-27 Corning Incorporated Shaped-tube electrolytic polishing process
WO2017220633A1 (en) * 2016-06-21 2017-12-28 Extrude Hone Gmbh Electrolytic polishing method and device and method for producing a cathode

Families Citing this family (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0730692Y2 (en) * 1988-11-14 1995-07-12 石川島播磨重工業株式会社 Electrolytic corrosion device for inner surface of small diameter pipe
JPH0794090B2 (en) * 1989-11-01 1995-10-11 工業技術院長 Electro-abrasive grain super-mirror finishing method for inner surface of small diameter tube
JPH06959B2 (en) * 1989-11-22 1994-01-05 工業技術院長 High-speed electrolytic rough finishing method
US5413463A (en) * 1991-12-30 1995-05-09 General Electric Company Turbulated cooling passages in gas turbine buckets
US5507923A (en) * 1993-11-09 1996-04-16 Stouse; Henry J. Method and apparatus for electrolytic polishing of tubular products
US5819400A (en) * 1996-06-25 1998-10-13 Smith & Wesson Corp. Method of manufacturing an electrode assembly for electrochemically etching rifling in gun barrels
US6168691B1 (en) * 1996-08-09 2001-01-02 Atotech Deutschland Gmbh Device for electrochemical treatment of elongate articles
US5958195A (en) * 1997-05-22 1999-09-28 Therma Corporation, Inc. Tube inner surface electropolishing device
US6217726B1 (en) * 1997-05-22 2001-04-17 Therma Corporation, Inc. Tube inner surface electropolishing device with electrolyte dam
JPH11138350A (en) * 1997-11-10 1999-05-25 Kobe Steel Ltd Method and device for grinding of internal surface of cylindrical part in aluminum hollow extruding section and aluminum hollow extruding section
IT1311147B1 (en) * 1999-11-04 2002-03-04 Edk Res Ag CLEANING MACHINE LOCALIZED WITH CELL, ELECTROLYTIC AND / OR ADULTRASONIC, PICKLING AND / OR POLISHING
US6277264B1 (en) 2000-02-02 2001-08-21 Therma Corporation, Inc. System and method for using multiple lead connections in an electropolishing process
US6547950B1 (en) 2000-02-02 2003-04-15 Therma Corporation, Inc. Cathode rinsing station and method
US6402908B1 (en) 2000-02-02 2002-06-11 Therma Corporation, Inc. Pipe electropolishing apparatus using an electrolyte heater and cooler
US6523615B2 (en) 2000-03-31 2003-02-25 John Gandy Corporation Electropolishing method for oil field tubular goods and drill pipe
US6428681B1 (en) 2000-12-06 2002-08-06 Therma Corporation, Inc. System and method for reversing electrolyte flow during an electropolishing operation
US6712668B2 (en) 2000-12-06 2004-03-30 Therma Corporation, Inc. System and method for electropolishing nonuniform pipes
TW572063U (en) * 2001-11-28 2004-01-11 Ind Tech Res Inst An electropolishing process means for an inner surface of a long tube
TW530717U (en) * 2001-12-13 2003-05-01 Ind Tech Res Inst An apparatus for electrolyzing polishing/grinding internal surface of long tube
US8492489B2 (en) 2004-02-13 2013-07-23 Total Petrochemicals Research Feluy Double loop technology
US8201619B2 (en) 2005-12-21 2012-06-19 Exxonmobil Research & Engineering Company Corrosion resistant material for reduced fouling, a heat transfer component having reduced fouling and a method for reducing fouling in a refinery
EP1979700A2 (en) 2005-12-21 2008-10-15 ExxonMobil Research and Engineering Company Corrosion resistant material for reduced fouling, heat transfer component with improved corrosion and fouling resistance, and method for reducing fouling
WO2010142550A1 (en) * 2009-06-08 2010-12-16 Novo Nordisk A/S A method for manufacturing a needle cannula having improved flow properties
DE102016100558B4 (en) * 2016-01-14 2023-08-10 Plasotec Gmbh Polishing head and method for plasma polishing an inner surface of a workpiece
US10864567B2 (en) 2018-04-17 2020-12-15 Government Of The United States As Represented By The Secretary Of The Army Systems and methods for electroprocessing a gun barrel using a moving electrode
CN115122227B (en) * 2022-06-20 2023-06-27 沈阳理工大学 Movable plasma electrochemical polishing device for inner surface of spiral deep hole with special-shaped cross section of metal pipe part
EP4309811B1 (en) * 2022-07-18 2024-09-25 Hammann GmbH Method for the electromechanical removal of deposits in pipelines or apparatus

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3202598A (en) * 1963-03-22 1965-08-24 Titanium Metals Corp Electrolytic polishing tool
FR2561672A1 (en) * 1984-03-21 1985-09-27 Travaux Milieu Ionisant Electrolysis device usable especially for radioactive decontamination of metal surfaces

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2764540A (en) * 1952-09-10 1956-09-25 William G Farin Method and means for electropolishing inner surfaces
DE1202607B (en) * 1961-01-20 1965-10-07 Nyby Bruk Ab Process for anodic surface treatment of metal objects
DE1496727B2 (en) * 1963-06-18 1972-03-02 Benteler Werke AG, Werk Neuhaus, 4794 Schloß Neuhaus METHOD OF ELECTROLYTIC TREATMENT OF THE INTERNAL AND EXTERNAL SURFACE OF PIPES
JPS5691380U (en) * 1979-12-14 1981-07-21
US4369101A (en) * 1980-05-02 1983-01-18 Nukem Gmbh Apparatus for electropolishing tubes
JPS6050878A (en) * 1983-08-30 1985-03-20 日本電気株式会社 Connector
DE3343396A1 (en) * 1983-11-30 1985-06-05 Kraftwerk Union AG, 4330 Mülheim METHOD FOR DECONTAMINATING METALLIC COMPONENTS OF A NUCLEAR TECHNICAL PLANT
US4601802A (en) * 1984-07-31 1986-07-22 The Upjohn Company Apparatus for internally electropolishing tubes

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3202598A (en) * 1963-03-22 1965-08-24 Titanium Metals Corp Electrolytic polishing tool
FR2561672A1 (en) * 1984-03-21 1985-09-27 Travaux Milieu Ionisant Electrolysis device usable especially for radioactive decontamination of metal surfaces

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0607894A1 (en) * 1993-01-19 1994-07-27 Corning Incorporated Shaped-tube electrolytic polishing process
WO2017220633A1 (en) * 2016-06-21 2017-12-28 Extrude Hone Gmbh Electrolytic polishing method and device and method for producing a cathode

Also Published As

Publication number Publication date
EP0247209B1 (en) 1990-07-18
ATE54681T1 (en) 1990-08-15
JPH0765240B2 (en) 1995-07-12
DE3672831D1 (en) 1990-08-23
JPS62290899A (en) 1987-12-17
US4772367A (en) 1988-09-20

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