EP0247209B1 - 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
EP0247209B1
EP0247209B1 EP86106812A EP86106812A EP0247209B1 EP 0247209 B1 EP0247209 B1 EP 0247209B1 EP 86106812 A EP86106812 A EP 86106812A EP 86106812 A EP86106812 A EP 86106812A EP 0247209 B1 EP0247209 B1 EP 0247209B1
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EP
European Patent Office
Prior art keywords
polishing head
electrolyte
dielectric
cathode
polishing
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EP86106812A
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German (de)
French (fr)
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EP0247209A1 (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 DE8686106812T priority Critical patent/DE3672831D1/en
Priority to EP86106812A priority patent/EP0247209B1/en
Priority to AT86106812T priority patent/ATE54681T1/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 a corresponding method for electrochemical polishing and / or pickling pipe inner surfaces .
  • 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.
  • a device for electropolishing the inner walls of pipes is known from US Pat. No. 3,202,598, a gap being present for the electrolyte between a cathode moving in the pipe and the inner surface of the pipe. In this device, however, no dielectric is printed between the cathode and the inner wall.
  • 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.
  • 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 electrolyte stream flowing into the polishing head is divided into an anodic partial stream and a cathodic partial stream, the anodic partial stream passing through the dielectric and the inner surface of the tube, but not the cathode, while the cathodic partial stream passes Cathode, but not the inner surface of the tube.
  • 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, in a known manner, effects the electrochemical removal and polishing 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 passes only the cathodes 26, but not the dielectric 18 and the working gap 28.
  • the hydrogen gas formed on the cathodes 26 does not reach the dielectric 18 and also not to the inner surface 16 to be polished, which on the one hand prevents that Dielectric 18 is loaded with hydrogen gas and on the other hand harmful effects of the hydrogen on the inner surface 16 are avoided.

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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

An apparatus and a method serving for electrochemically polishing and/or pickling the inner surfaces (16) of pipes (10) provide for a polishing head (12) to be moved through the pipe. The polishing head (12) comprises a dielectric outer wall which defines a narrow working gap (28) together with the inner pipe surface (16) to be cleaned, the electrolyte flowing through said gap. This permits electrochemical polishing of high quality of the inside surface of the pipe with little consumption of electrolyte. The electrolyte stream may be divided into cathodic and anodic partial streams (30 and 32, respectively).

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 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 Hochdruckstrahis 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.From European patent application 82 104 946.7 a method and a device for electrochemically polishing the inner walls of pipes are also known, 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.

Aus den US-A 3 202 598 ist eine Vorrichtung zum Elektropolieren der Innenwände von Rohren bekannt, wobei ein Spalt für den Elektrolyt zwisschen einer im Rohr bewegender Kathode und der Innenfläche des Rohres vorhanden ist. Bei dieser Vorrichtung ist jedoch kein Dielektikum zwischen der Kathode und der Innenwand aufgedruckt.A device for electropolishing the inner walls of pipes is known from US Pat. No. 3,202,598, a gap being present for the electrolyte between a cathode moving in the pipe and the inner surface of the pipe. In this device, however, no dielectric is printed between the cathode and the inner wall.

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 äls 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 only partially acts on a particular section of the inner wall of the tube (which is therefore considerably shorter than the tube to be electropolished) 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. In the known devices, an increased metal content in the electrolytes leads to 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.Due to the design of a working gap between the dielectric and the inner surface of the tube, the elec Trolyte consumption significantly reduced 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 lonenaustauscher 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 electrolyte stream flowing into the polishing head is divided into an anodic partial stream and a cathodic partial stream, the anodic partial stream passing through the dielectric and the inner surface of the tube, but not the cathode, while the cathodic partial stream passes Cathode, but not the inner surface of the tube.

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 22' 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 22 'passes through the working gap 28 and, in a known manner, effects the electrochemical removal and polishing 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 passes only the cathodes 26, but not the dielectric 18 and the working gap 28. Thus, the hydrogen gas formed on the cathodes 26 does not reach the dielectric 18 and also not to the inner surface 16 to be polished, which on the one hand prevents that Dielectric 18 is loaded with hydrogen gas and on the other hand harmful effects of the hydrogen on the inner surface 16 are avoided.

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.2 passes 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 (8)

1. An apparatus for electrochemically polishing and/or pickling the inner surfaces (36) of pipes (10), connected as anodes, by means of a flowing electrolyte (22), comprising
- a polishing head (32),
- means (14) for moving the polishing head (12) through the pipe (10),
- supply lines (14; 25) to feed the electrolyte and electric current to the polishing head (12), and
- a cathode (26) arranged in the interior of the polishing head (32), characterized in that a dielectric (18) is arranged between the cathode (26) and the inner surface (76) of the pipe (10) and permits the electrolyte to pass, leaving a gap (28) for passage of the electrolyte stream (22', 32) between itself and the inner surface (16) of the pipe (10).
2. The apparatus as claimed in claim 1, characterized in that the polishing head (12) is at least approximately cylindrical in shape, the dielectric (18) forming, at least partly, the cylinder jacket.
3. The apparatus as claimed in claim 1 or 2, characterized in that means (14; 25, 26) are provided which divide the electrolyte stream (22) entering the polishing head (12) into an anodic partial stream (32) and a cathodic partial stream (30) such that the anodic partial stream flows past the dielectric (18) and the inner pipe surface (16) but not past the cathode (26) while the cathodic partial stream (30) flows past the cathode (26) but not past the inner pipe surface (16).
4. The apparatus as claimed in one of claims 1 to 3, characterized in that the polishing head (12) is connected to a guide means (14) which is embodied by a tube and through which extend the electric lines (25) of the polishing head (25).
5. The apparatus as claimed in one of claims 1 to 3, characterized in that the polishing head (12) is supplied with electrolyte and electric current by way of an elastic hose line and is pulled through the pipe (10) by means of a rod or rope.
6. A method of electrochemically polishing and/or pickling the inner surface (16) of pipes (10), wherein an electrolyte flows past the inner pipe surface connected as anode, characterized in that the electrolyte stream (22) is pumped into a polishing head (12) provided with a cathode (26) and out of the same through a dielectric (18) into a working gap (28) defined between the dielectric and the inner pipe surface (16).
7. The method as claimed in claim 6, characterized in that the electrolyte stream (22) is divided in the polishing head (12) into an anodic partial stream (32) and a cathodic partial stream (30), the anodic partial stream flowing past the dielectric (18) and the inner pipe surface (16) but not past the cathode (26) and the cathodic partial stream (30) flowing past the cathode (26) but not past the dielectric and the inner pipe surface (16).
8. The method as claimed in claim 6 or 7, characterized in that the polishing head (12) is moved through the pipe (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
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
AT86106812T ATE54681T1 (en) 1986-05-20 1986-05-20 APPARATUS AND METHOD FOR ELECTROCHEMICAL POLISHING THE INTERNAL SURFACE 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 EP0247209A1 (en) 1987-12-02
EP0247209B1 true 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)

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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
US8286695B2 (en) 2005-12-21 2012-10-16 Exxonmobil Research & Engineering Company Insert and method for reducing fouling in a process stream
DE102016100558A1 (en) * 2016-01-14 2017-07-20 Plasotec Gmbh Polishing head and method for plasma polishing an inner surface of a workpiece
EP4309811A1 (en) * 2022-07-18 2024-01-24 Hammann GmbH Method for the electromechanical removal of deposits in pipelines or apparatus

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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
US8286695B2 (en) 2005-12-21 2012-10-16 Exxonmobil Research & Engineering Company Insert and method for reducing fouling in a process stream
US8469081B2 (en) 2005-12-21 2013-06-25 Exxonmobil Research And Engineering Company Corrosion resistant material for reduced fouling, a heat transfer component having reduced fouling and a method for reducing fouling in a refinery
DE102016100558A1 (en) * 2016-01-14 2017-07-20 Plasotec Gmbh Polishing head and method for plasma polishing an inner surface of a workpiece
DE102016100558B4 (en) 2016-01-14 2023-08-10 Plasotec Gmbh Polishing head and method for plasma polishing an inner surface of a workpiece
EP4309811A1 (en) * 2022-07-18 2024-01-24 Hammann GmbH Method for the electromechanical removal of deposits in pipelines or apparatus

Also Published As

Publication number Publication date
EP0247209A1 (en) 1987-12-02
JPS62290899A (en) 1987-12-17
ATE54681T1 (en) 1990-08-15
JPH0765240B2 (en) 1995-07-12
DE3672831D1 (en) 1990-08-23
US4772367A (en) 1988-09-20

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