EP0018522A1 - Method and apparatus for sustaining a cathodic protection against corrosion - Google Patents

Method and apparatus for sustaining a cathodic protection against corrosion Download PDF

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Publication number
EP0018522A1
EP0018522A1 EP80101936A EP80101936A EP0018522A1 EP 0018522 A1 EP0018522 A1 EP 0018522A1 EP 80101936 A EP80101936 A EP 80101936A EP 80101936 A EP80101936 A EP 80101936A EP 0018522 A1 EP0018522 A1 EP 0018522A1
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EP
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Prior art keywords
current
protective
potential
phase
protective current
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EP80101936A
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German (de)
French (fr)
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EP0018522B1 (en
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Hans Prof. Dr. Rickert
Günther Dr. Holzäpfel
Milan Saskovic
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RWE Energie AG
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Vereinigte Elektrizitatswerke Westfalen AG
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
    • C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
    • C23F13/04—Controlling or regulating desired parameters

Definitions

  • the invention relates to a method and a device for maintaining a cathodic corrosion protection for metallic surfaces in contact with an electrolyte with external current, using an inert electrode as external current anode and a potentiostat.
  • the inventor proposed in a not yet published application to shield the reference electrode, to put it simply, with a kind of Faraday cage, so that a continuous IR-free measurement is possible.
  • the object of the invention is to provide a solution with which a very good measurement of the protective potential on the one hand and on the other hand an optimal regulation of the protective current is possible, a reference electrode susceptible to faults being completely avoided.
  • a reference electrode is completely avoided by the procedure according to the invention. This is possible because the inert electrodes used here have a characteristic potential in this state due to the development of oxygen during the polarization, which occupies the surface, this oxygen occupancy being retained for a certain time after the protective current has been switched off. This potential corresponds to that of an oxygen electrode, so that an exact measurement is possible with Hflf-e of this defined potential. It also follows from this switch-off measurement that the IR-free potential is measured by the immediate disappearance of the disturbing ohmic voltage drop after the switch-off.
  • the interval-like shutdown of the protective current is harmless for the corrosion protection itself, because here the protection potential also remains on the surfaces to be protected by pre-polarization a certain time after the shutdown, since the processes responsible for the corrosion take place comparatively slowly.
  • the invention provides that a control deviation is integrated several times during the protective current shutdown phase and the integrated voltage controls the protective current during the following protective current phase.
  • This configuration makes it possible to set the protective current very precisely and to keep it constant, it being possible, due to a further feature of the invention, which is that the protective current switch-off phase is kept many times smaller than the protective current phase, that the advantages of a practical constant protective current applied to the surface to be protected.
  • the protective current phase is in the range of approximately half a millisecond, which means for the electrochemical processes in question that the protective potential is always maintained.
  • a device for carrying out the method according to the invention is characterized according to the invention by a power supply unit with transformer and rectifier, a voltage sender for setting the protection potential, ei Isolation amplifier and electronic double switch with control element as well as an integrator and a current amplifier, the elements being connected in terms of circuitry to the surface to be protected and an electrode performing the double function as external current anode and reference electrode.
  • This device represents a particularly expedient way of realizing the method according to the invention, but the invention is not restricted to this special device.
  • the surface 1 to be protected is in contact with an electrolyte 2, for example sea water in a ship's hull or household water in a hot water boiler or the like.
  • the surface 1 to be protected is connected to a target voltage generator 3, with which the Protection potential E should be able to be set.
  • the setpoint voltage generator 3 is connected to an isolating amplifier 5, one output 6 of which acts on part 7 of a double switch 8.
  • the other part of the double switch 8 is designated 9.
  • An integrator 10 is located between the two parts 7 and 9 of the double switch 8.
  • the double switch 8 as can be seen from FIG. 1, is actuated by a control element 11, which once comprises a timer and performs the functions "on / off".
  • a current amplifier 12 is connected behind the part 9 of the double switch 8, one output of which is connected via the line 13 to an electrode 14 immersed in the electrolyte 2.
  • the electrode 14 in turn is also connected to the isolation amplifier 5 via a line 15.
  • the system receives the energy necessary for regulating and maintaining the protection potential by means of a power supply unit 16, which is indicated as a hint, the inputs and outputs of which are labeled with the corresponding voltage designations which correspond to those of the inputs and outputs of the protection system.
  • the mode of operation of the device according to the invention is as follows: During the potential interval determined by the control element 11, the switch 8 decouples the transistor 7 serving as a current amplifier and the potential E is compared between the electrode 14, which acts as a reference electrode in this switching state, and the surface 1 to be protected, the surface to be protected lying on ground. Any existing control deviation (E ist - E soll ) is integrated several times by the integrator 10 in the potential interval, in each case in a time period that is still considerably smaller than the potential interval itself. This integrated voltage controls the protective current in the current interval determined by the control element 11 which flows between the electrode 14, which acts as an external current anode in this phase, and the surface 1 to be protected.
  • FIGS. 2 and 3 The results of a test with a device according to the invention are plotted in FIGS. 2 and 3.
  • An electrode made of platinized titanium was used for the experiment, the surface to be protected was that of an iron object. Water with a conductivity of 110 ⁇ S cm -1 was used as the electrolyte.
  • the potential interval during the experiment lasted approx. 40 us.
  • the current interval lasted 400 us.
  • the piece of iron used in the test showed no signs of corrosion even after a long test period.

Abstract

1. A method of maintaining cathodic corrosion protection for metal surface which are in contact with an electrolyte, with external current, using an inert electrode as the external current anode and a potentiostat, characterised in that periodically the protective current is switched off and a measurement is taken of the potential (Eist ) directly between the external current anode which in this phase operates as a reference electrode, and the surface to be protected, and the potential (Eist ) is compared to the protective potential (E soll ) which is set at the potentiostat, and the difference (E ist - E soll ) is used directly as a control value in respect of the protective current.

Description

Die Erfindung richtet sich auf ein Verfahren und eine Vorrichtung zur Aufrechterhaltung eines kathodischen Korrosionsschutzes für metallische, mit einem Elektrolyten in Berührung stehende Flächen mit Fremdstrom, unter Verwendung einer inerten Elektrode als Fremdstromanode und eines Potentiostaten.The invention relates to a method and a device for maintaining a cathodic corrosion protection for metallic surfaces in contact with an electrolyte with external current, using an inert electrode as external current anode and a potentiostat.

Um einen optimalen Korrosionsschutz zu erreichen, sind schon eine Vielzahl von Möglichkeiten bekannt, wobei die einfachste und seit langem bekannte Möglichkeit in der Verwendung von sogenannten Opferanoden besteht, die aus einem gegenüber dem zu schützenden Metall sehr viel unedleren Metall bestehen und mit diesem zusammen kurzgeschlossen sind, so daß in Verbindung mit dem Elektrolyten ein galvanisches Element entsteht, von dem ein gewisser Schutzstrom erzeugbar ist. Ein verbesserter Korrosionsschutz läßt sich durch das Anlegen eines Fremdstromes erreichen. Um hierbei Änderungen am zu schützenden Gegenstand miterfassen zu können, ist esbekannt, das Schutzpotential mittels einer Bezugselektrode zu messen und mit Hilfe eines Potentiostaten konstant zu halten.In order to achieve optimal corrosion protection, a multitude of possibilities are already known, the simplest and long-known possibility being the use of so-called sacrificial anodes, which consist of a metal that is much less noble than the metal to be protected and are short-circuited with it , so that a galvanic element is produced in connection with the electrolyte, from which a certain protective current can be generated. Improved corrosion protection can be achieved by applying an external current. In order to be able to detect changes to the object to be protected, it is known to measure the protection potential by means of a reference electrode and to keep it constant with the aid of a potentiostat.

Bei derartigen Messungen wird aber aufgrund des elektrischen Feldes und eines endlichen Abstandes der Bezugselektrode von der zu schützenden Wand ein Anteil, die sogenannte Widerstandspolarisation bzw. der IR-Anteil, mitgemessen, was zu Verfälschungen führen kann, die die Wirksamkeit des kathodischen Korrosionsschutzes, je nach Einsatzbereich, in Frage stellen können.In such measurements, however, due to the electric field and a finite distance of the reference electrode from the wall to be protected, a portion, the so-called resistance polarization or the IR portion, is also measured, which can lead to falsifications that affect the effectiveness of the cathodic protection against corrosion, depending on the area of application.

Um diese Widerstandspolarisation zu unterdrücken, ist vom Erfinder in einer noch nicht veröffentlichten Anmeldung vorgeschlagen worden, die Bezugselektrode, vereinfacht ausgedrückt, mit einer Art Faraday'schen Käfig abzuschirmen, so daß eine kontinuierliche IR-freie Messung möglich ist.In order to suppress this resistance polarization, the inventor proposed in a not yet published application to shield the reference electrode, to put it simply, with a kind of Faraday cage, so that a continuous IR-free measurement is possible.

Diese bekannte Art der Messung mit einer abgeschirmten Bezugselektrode und Regelung mit einem Potentiostaten ermöglicht einen sehr guten Korrosionsschutz, jedoch wird dabei nach wie vor eine Bezugselektrode angewandt, die im Gesamtsystem das empfindlichste Bauteil darstellt, mit der geringsten Lebensdauer und der größten Störanfälligkeit.This known type of measurement with a shielded reference electrode and control with a potentiostat enables very good corrosion protection, however, a reference electrode is still used, which is the most sensitive component in the overall system, with the lowest service life and the greatest susceptibility to faults.

Aufgabe der Erfindung ist die Schaffung einer Lösung, mitder eine sehr gute Messung des Schutzpotentiales einerseits und andererseits eine optimale Regelung des Schutzstromes möglich ist, wobei eine störanfällige Bezugselektrode gänzlich vermieden wird.The object of the invention is to provide a solution with which a very good measurement of the protective potential on the one hand and on the other hand an optimal regulation of the protective current is possible, a reference electrode susceptible to faults being completely avoided.

Diese Aufgabe wird mit einem Verfahren der eingangs bezeichneten Art gemäß der Erfindung dadurch gelöst, daß periodisch der Schutzstrom abschaltet und das vorhandene Potential direkt zwischen der in dieser Phase als Bezugselektrode wirkenden Fremdstromanode und der zu schützenden Oberfläche gemessen und mit dem am Potentiostaten eingestellten Schutzpotential verglichen wird und die Differenz direkt als Regelgröße für den Schutzstrom herangezogen wird.This object is achieved with a method of the type described at the outset according to the invention in that the protective current periodically switches off and the potential present directly between the reference element in this phase trode acting external current anode and the surface to be protected is measured and compared with the protection potential set on the potentiostat and the difference is used directly as a control variable for the protection current.

Durch die erfindungsgemäße Verfahrensweise wird eine Bezugselektrode vollständig vermieden. Dies ist dadurch möglich , da die hier Verwendung findenden inerten Elektroden durch die Entwicklung von Sauerstoff während der Polarisation, der die Oberfläche belegt, wobei diese Sauerstoffbelegung.nach Abschalten des Schutzstromes noch eine gewisse Zeit erhalten bleibt, in diesem Zustand ein charakteristisches Potential aufweisen. Dieses Potential entspricht demjenigen einer Sauerstoffelektrode, so daß mit Hflf-e dieses definierten Potentiales eine exakte Messung möglich ist. Auch ergibt sich durch diese Abschaltmessung, daß durch sofortiges Verschwinden des störenden ohm'schen Spannungsabfalles nach dem Abschalten das IR-freie Potential gemessen wird.A reference electrode is completely avoided by the procedure according to the invention. This is possible because the inert electrodes used here have a characteristic potential in this state due to the development of oxygen during the polarization, which occupies the surface, this oxygen occupancy being retained for a certain time after the protective current has been switched off. This potential corresponds to that of an oxygen electrode, so that an exact measurement is possible with Hflf-e of this defined potential. It also follows from this switch-off measurement that the IR-free potential is measured by the immediate disappearance of the disturbing ohmic voltage drop after the switch-off.

Für den Korrosionsschutz selbst ist die intervallartige Abschaltung des Schutzstromes unschädlich, weil hier an den zu schützenden Flächen durch Vorpolarisation das Schutzpotential ebenfalls eine gewisse Zeit-nach dem Abschalten bestehen bleibt, da die für die Korrosion verantwortlichen Vorgänge vergleichsweise träge ablaufen.The interval-like shutdown of the protective current is harmless for the corrosion protection itself, because here the protection potential also remains on the surfaces to be protected by pre-polarization a certain time after the shutdown, since the processes responsible for the corrosion take place comparatively slowly.

In Ausgestaltung sieht die Erfindung vor, daß während der Schutzstromabschaltphase eine Regelabweichung mehrfach aufintegriert und die integrierte Spannung den Schutzstrom während der folgenden Schutzstromphase steuert. Durch diese Ausgestaltung wird es möglich, den Schutzstrom sehr genau einzustellen und konstant zu halten, wobei aufgrund eines weiteren Merkmales der ERfindung, welches darin besteht, daß die Schutzstromabschaltphase um ein vielfaches kleiner als die Schutzstromphase gehalten wird, erreichbar ist, daß die Vorteile einer praktisch stetigen Schutzstrombeaufschlagung auf der zu schützenden Oberfläche beibehalten werden.In an embodiment, the invention provides that a control deviation is integrated several times during the protective current shutdown phase and the integrated voltage controls the protective current during the following protective current phase. This configuration makes it possible to set the protective current very precisely and to keep it constant, it being possible, due to a further feature of the invention, which is that the protective current switch-off phase is kept many times smaller than the protective current phase, that the advantages of a practical constant protective current applied to the surface to be protected.

In weiterer Ausgestaltung ist erfindungsgemäß vorgesehen, daß die Schutzstromphase im Bereich etwa einer halben Millisekunde liegt, was für die hier in Rede stehenden elektrochemischen Vrgänge bedeutet, daß das Schutzpotential immer aufrechterhalten bleibt.In a further embodiment it is provided according to the invention that the protective current phase is in the range of approximately half a millisecond, which means for the electrochemical processes in question that the protective potential is always maintained.

Durch die erfindungsgemäße Verfahrensweise sind Zustandsänderungen im System sehr rasch kompensierbar, so daß ein optimaler Korrosionsschutz erreich-bar ist.Due to the procedure according to the invention, changes in state in the system can be compensated for very quickly, so that optimum corrosion protection can be achieved.

Eine Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zeichnet sich nach der Erfindung durch einen Netzteil mit Transformator und Gleichrichter, einen Sσllspannungsgeber zur Einstellung des Schutzpotentiales, einen Trennverstärker und elektronischen Doppelschalter mit Steuelement sowie einen Integrator und einen Stromverstärker aus, wobei die Elemente in schaltungsmäßiger Verbindung mit der zu schützenden Oberfläche und einer die Doppelfunktion als Fremdstromanode und Bezugselektrode ausübenden Elektrode stehen. Diese Vorrichtung stellt eine besonders zweckmäßige Art dar, das erfindungsgemäße Verfahren zu verwirklichen, jedoch ist die Erfindung nicht auf diese spezielle Vorrichtung beschränkt.A device for carrying out the method according to the invention is characterized according to the invention by a power supply unit with transformer and rectifier, a voltage sender for setting the protection potential, ei Isolation amplifier and electronic double switch with control element as well as an integrator and a current amplifier, the elements being connected in terms of circuitry to the surface to be protected and an electrode performing the double function as external current anode and reference electrode. This device represents a particularly expedient way of realizing the method according to the invention, but the invention is not restricted to this special device.

Die Erfindung ist nachstehend anhand der Zeichnung beispielsweise näher erläutert. Diese zeigt in

  • Fig. 1 ein Schaltbild einer Vorrichtung,
  • Fig. 2 ein Spannungs/Zeitdiagramm und in
  • Fig. 3 ein Strom/Zeitdiagramm.
The invention is explained below with reference to the drawing, for example. This shows in
  • 1 is a circuit diagram of a device,
  • Fig. 2 is a voltage / time diagram and in
  • Fig. 3 is a current / time diagram.

Wie sich aus Fig. 1 ergibt, steht die zu schützende Oberfläche 1 in Kontakt mit einem Elektrolyten 2, beispielsweise Meerwasser bei einem Schiffsrumpf oder Haushaltswasser bei einem Warmwasserboiler o. dgl. Die zu schützende Oberfläche 1 ist mit einem Sollspannungsgeber 3 verbunden, mit dem das Schutzpotential Esoll eingestellt werden kann.As can be seen from Fig. 1, the surface 1 to be protected is in contact with an electrolyte 2, for example sea water in a ship's hull or household water in a hot water boiler or the like. The surface 1 to be protected is connected to a target voltage generator 3, with which the Protection potential E should be able to be set.

über die Leitung 4 ist der Sollspannungsgeber 3 mit einem Trennverstärker 5 verbunden, dessen einer Ausgang 6 den einen Teil 7 eines Doppelschalters 8 beaufschlagt. Der andere Teil des Doppelschalters 8 ist mit 9 bezeichnet. Zwischen den beiden Teilen 7 und 9 des Doppelschalters 8 liegt ein Integrator 10.Via the line 4, the setpoint voltage generator 3 is connected to an isolating amplifier 5, one output 6 of which acts on part 7 of a double switch 8. The other part of the double switch 8 is designated 9. An integrator 10 is located between the two parts 7 and 9 of the double switch 8.

Der Doppelschalter 8 wird, wie sich aus Fig. 1 ergibt, von einem Steuerelement 11 betätigt, welches einmal einen Zeitgeber umfaßt und die Funktionen "Ein/Aus" ausübt. Hinter den Teil 9 des Doppelschalters 8 ist ein Stromverstärker 12 geschaltet, dessen einer Ausgang über die Leitung 13 mit einer im Elektrolyten 2 eintauchenden Elektrode 14 verbunden ist. Die Elektrode 14 ihrerseits ist auch über eine Leitung 15 mit dem Trennverstärker 5 verbunden.The double switch 8, as can be seen from FIG. 1, is actuated by a control element 11, which once comprises a timer and performs the functions "on / off". A current amplifier 12 is connected behind the part 9 of the double switch 8, one output of which is connected via the line 13 to an electrode 14 immersed in the electrolyte 2. The electrode 14 in turn is also connected to the isolation amplifier 5 via a line 15.

Die zur Regelung und zur Aufrechterhaltung des Schutzpotentiales notwendige Energie erhält das System durch ein andeutungsweise wiedergegebenes Netzteil 16, dessen Ein-und Ausgänge mit den entsprechenden Spannungsbezeichnungen, die denen der Ein- und Ausgänge des Schutzsystemes entsprechen, bezeichnet sind.The system receives the energy necessary for regulating and maintaining the protection potential by means of a power supply unit 16, which is indicated as a hint, the inputs and outputs of which are labeled with the corresponding voltage designations which correspond to those of the inputs and outputs of the protection system.

Die Wirkungsweise der Vorrichtung nach der Erfindung ist die folgende: Während des vom Steuerelement 11 bestimmten Potentialintervalles wird durch den Schalter 8 der als Stromverstärker dienende Transistor 7 abgekoppelt und das Potential Eist zwischen der in diesem Schaltzustand als Bezugselektrode wirkenden Elektrode 14 und der zu schützenden Oberfläche 1 verglichen, wobei die zu schützende Oberfläche auf Masse liegt. Eine ggf. vorhandene Regelabweichung (Eist - Esoll ) wird vom Integrator 10 im Potentialintervall mehrfach aufintegriert und zwar jeweils in einer Zeitspanne, die noch wesentlich kleiner ist, als das Potentialintervall selbst. Diese integrierte Spannung steuert im vom Steuerelement 11 bestimmten Stromintervall den Schutzstrom, der zwischen der in dieser Phase als Fremdstromanode wirkenden Elektrode 14 und der zu schützenden Oberfläche 1 fließt.The mode of operation of the device according to the invention is as follows: During the potential interval determined by the control element 11, the switch 8 decouples the transistor 7 serving as a current amplifier and the potential E is compared between the electrode 14, which acts as a reference electrode in this switching state, and the surface 1 to be protected, the surface to be protected lying on ground. Any existing control deviation (E ist - E soll ) is integrated several times by the integrator 10 in the potential interval, in each case in a time period that is still considerably smaller than the potential interval itself. This integrated voltage controls the protective current in the current interval determined by the control element 11 which flows between the electrode 14, which acts as an external current anode in this phase, and the surface 1 to be protected.

Dieser Vorgang wird periodisch wiederholt. Im Falle einer Regelabweichung wird der Schutzstrom entsprechend verändert, ist die Regelabweichung null, so bleibt der Schutzstrom konstant.This process is repeated periodically. In the event of a control deviation, the protective current is changed accordingly; if the control deviation is zero, the protective current remains constant.

In den Fig. 2 und 3 sind Ergebnisse eines Versuches mit einer erfindungsgemäßen Vorrichtung aufgetragen. Zum Versuch wurde eine Elektrode aus platiniertem Titan benutzt, die zu schützende Oberfläche war die eines Eisengegenstandes. Als Elektrolyt wurde Wasser mit einer Leitfähigkeit von 110 µS cm-1 verwendet. Bei diesem Versuch wurde eine Sollspannung Esoll = 2300 mV zwischen der Elektrode und dem Eisen eingestellt. Das Potentialintervall dauerte beim Versuch ca. 40 us. Das Stromintervall dauerte 400 us. Die sich aus den Figuren ergebende Differenz zwischen den Potentialwerten im Strom- und Potentialintervall entspricht dem ohm'schen Spannungsabfall, der im Falle des Versuches Δ U = 200 mV ergab.The results of a test with a device according to the invention are plotted in FIGS. 2 and 3. An electrode made of platinized titanium was used for the experiment, the surface to be protected was that of an iron object. Water with a conductivity of 110 µS cm -1 was used as the electrolyte. In this experiment, a target voltage was set to E = 2300 mV between the electrode and the iron. The potential interval during the experiment lasted approx. 40 us. The current interval lasted 400 us. The the difference between the potential values in the current and potential intervals resulting from the figures corresponds to the ohmic voltage drop which, in the case of the test, gave Δ U = 200 mV.

Das beim Versuch benutzte Eisenstück wies auch nach längerer Versuchsdauer keine Spuren von Korrosion auf.The piece of iron used in the test showed no signs of corrosion even after a long test period.

Natürlich it das beschriebene Ausführungsbeispiel in vielfacher Hinsicht abzuändern, ohne den Grundgedanken der Erfindung zu verlassen. So können statt der dargestellten Schaltung und der dort funktional verbundenen Bauelemente auch andere Teile verwendet werden. Als zu schützende Oberfläche kommen alle der Korrosion unterworfenen Oberflächen in Frage, die ggf. auch nur zeitweise einem Elektrolyten ausgesetzt sind, beispielsweise Metalldächer bei Regen oder Schnee, Leitungsrohre, die dem Meerwasser, dem Grundwasser oder anderen Wässern ausgesetzt sind, Warmwasserboiler, Vorratskessel o. dgl.Of course, the described exemplary embodiment can be modified in many ways without departing from the basic idea of the invention. So other parts can be used instead of the circuit shown and the components that are functionally connected there. As a surface to be protected, all surfaces subject to corrosion come into question, which may be only temporarily exposed to an electrolyte, for example metal roofs when it is raining or snowing, pipes that are exposed to sea water, ground water or other water, hot water boilers, storage boilers or the like. the like

Claims (5)

1. Verfahren zur Aufrechterhaltung eines kathodischen Korrosionsschutzes für metallische, mit einem Elektrolyten in Berührung stehende Flächen, mit Fremdstrom unter Verwendung einer inerten Elektrode als Fremdstromanode und eines Potentiostaten, dadurch gekennzeichnet, daß periodisch der Schutzstrom abschaltet und das vorhandene Potential (Eist) direkt zwischen der in dieser Phase als Bezugselektrode wirkenden Fremdstromanode und der zu schützenden Oberfläche gemessen und mit dem am Potentiostaten eingestellten Schutzpotential (Esoll) verglichen wird und die Differenz (Eist - Esoll) direkt als Regelgröße für den Schutzstrom herangezogen wird.1. A method for maintaining a cathodic corrosion protection for metallic surfaces in contact with an electrolyte, with external current using an inert electrode as external current anode and a potentiostat, characterized in that the protective current switches off periodically and the existing potential (E is ) directly between in this phase as a reference electrode acting impressed current anode and the measured surface to be protected and (to e) with the value adjusted at the potentiostat protection potential is compared and the difference (e - e soll) is used directly as a control parameter for the protection current. 2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß während der Schutzstromabschaltphase eine Regelabweichung mehrfach aufintegriert und die integrierte Spannung den Schutzstrom während der folgenden Schutzstromphase steuert.2. The method according to claim 1, characterized in that a control deviation is integrated several times during the protective current switch-off phase and the integrated voltage controls the protective current during the following protective current phase. 3. Verfahren nach den Ansprüchen -1 oder 2, dadurch gekennzeichnet, daß die Schutzstromabschaltphase um ein vielfaches kleiner als die Schutzstromphase gehalten wird.3. The method according to claims -1 or 2, characterized in that the protective current shutdown phase is kept many times smaller than the protective current phase. 4. Verfahren nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, daß die Schutzstromphase im Bereich etwa einer halben Millisekunde liegt.4. The method according to any one of the preceding claims, characterized in that the protective current phase in the range approximately half a millisecond. 5. Vorrichtung zur Durchführung des Verfahrens nach Anspruch 1, gekennzeichnet durch einen Netzteil (16) mit Transformator und Gleichrichter, einen Sollspannungsgeber (3) zur Einstellung des Schutzpotentials (Esoll), einen Trennverstärker (5) und elektronischen Doppelschalter (8) mit Steuerelement (11) sowie einen Integrator (10) und einen Stromverstärker (12), wobei die Elemente in schaltungsmäßiger Verbindung mit der zu schützenden Oberfläche (1) und einer die Doppelfunktion als Fremdstromanode und Bezugselektrode ausübenden Elektrode (14) stehen.5. Apparatus for carrying out the method according to claim 1, characterized by a power supply (16) with transformer and rectifier, a set voltage generator (3) for setting the protective potential (E soll ), an isolation amplifier (5) and electronic double switch (8) with control element (11) and an integrator (10) and a current amplifier (12), the elements being connected in terms of circuitry to the surface to be protected (1) and an electrode (14) performing the double function as external current anode and reference electrode.
EP80101936A 1979-04-26 1980-04-10 Method and apparatus for sustaining a cathodic protection against corrosion Expired EP0018522B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80101936T ATE359T1 (en) 1979-04-26 1980-04-10 METHOD AND DEVICE FOR MAINTAINING CATHODIC CORROSION PROTECTION.

Applications Claiming Priority (2)

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DE2916934A DE2916934C2 (en) 1979-04-26 1979-04-26 Method and device for maintaining cathodic protection against corrosion
DE2916934 1979-04-26

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EP0018522A1 true EP0018522A1 (en) 1980-11-12
EP0018522B1 EP0018522B1 (en) 1981-11-04

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EP80101936A Expired EP0018522B1 (en) 1979-04-26 1980-04-10 Method and apparatus for sustaining a cathodic protection against corrosion

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Cited By (11)

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JPS57145988A (en) * 1981-03-05 1982-09-09 Mitsubishi Electric Corp Anticorrosive electrode device
WO1993004218A1 (en) 1991-08-14 1993-03-04 Cgr Di Cadignani P.I. Gino Process for mantaining a cathodic protection against corrosion and device for carrying out said process
WO1993011279A1 (en) * 1991-11-28 1993-06-10 Cyberdan A/S Electric power distribution system for active cathodic protection of reinforced concrete constructions
EP0565192A1 (en) * 1992-04-07 1993-10-13 Franciscus Brummelhuis Arrangement for cathodic protection
WO2009027402A1 (en) * 2007-08-31 2009-03-05 BSH Bosch und Siemens Hausgeräte GmbH Method for manufacturing a water-bearing domestic appliance
WO2009116901A1 (en) * 2008-03-19 2009-09-24 Ab Volvo Penta Control of a corrosion protection system
WO2009116900A1 (en) * 2008-03-19 2009-09-24 Ab Volvo Penta Control of a corrosion protection system
CN104674229A (en) * 2015-03-06 2015-06-03 中国石化管道储运有限公司 Intelligent remote monitoring and regulating system for cathode protection of underground pipelines
CN105987283A (en) * 2015-01-28 2016-10-05 上海远动科技有限公司 Cathodic protection remote monitoring device for natural gas pipelines based on an SCAD system
DE102017200954A1 (en) 2017-01-20 2018-07-26 BSH Hausgeräte GmbH Washing machine with improved corrosion stability and method of operation
EP3916128A1 (en) * 2020-05-27 2021-12-01 iCor Intelligent Corrosion Control GmbH Cathodic corrosion protection circuit arrangement and measurement assembly for cathodic corrosion protection

Families Citing this family (7)

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Publication number Priority date Publication date Assignee Title
DE3707791C1 (en) * 1987-03-11 1988-03-31 Ver Elek Zitaetswerke Westfale Method and device for maintaining cathodic corrosion protection for metallic surfaces with external current
FR2634867B1 (en) * 1988-07-26 1990-11-09 Advanced Technologies Internal METHOD AND DEVICE FOR MONITORING THE CATHODE PROTECTION OF A BURIED OR UNDERWATER METAL STRUCTURE
DE4107920A1 (en) * 1990-03-15 1991-09-19 Norsk Hydro Magnesium Killing hot water storage tank bacteria - by additional heat derived from inert electrode
DE4025088A1 (en) * 1990-08-08 1992-02-13 Vaw Ver Aluminium Werke Ag CATHODICAL CORROSION PROTECTION FOR AN ALUMINUM CONTAINING SUBSTRATE
DE4129712C1 (en) * 1991-09-06 1993-05-06 Buderus Heiztechnik Gmbh, 6330 Wetzlar, De Cathodic corrosion protection of enamelled water tank
US7372005B2 (en) 2004-09-27 2008-05-13 Aos Holding Company Water storage device having a powered anode
ES2409938B1 (en) * 2011-12-28 2014-08-22 Fagor, S. Coop. Method and device for cathodic corrosion protection

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DE1150555B (en) * 1958-10-08 1963-06-20 Engelhard Ind Inc Device for cathodic protection on ships
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CH589727A5 (en) * 1973-09-06 1977-07-15 Kuenzler Hans
DE2605088B1 (en) * 1976-02-10 1977-07-28 Ver Elek Zitaetswerke Westfale DEVICE FOR CATHODIC CORROSION PROTECTION WITH EXTERNAL CURRENT MANODE
US4138323A (en) * 1976-09-29 1979-02-06 Statsenko Nikolai N Apparatus for anodic protection against corrosion of metal objects in contact with electrically conductive media

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DE1150555B (en) * 1958-10-08 1963-06-20 Engelhard Ind Inc Device for cathodic protection on ships
CH589727A5 (en) * 1973-09-06 1977-07-15 Kuenzler Hans
DE2361547A1 (en) * 1973-12-11 1975-06-19 Karl Heinz Ortmann Cathodic protection of buried metal objects - using periodic switch-off potential for adjusting protective current
DE2605088B1 (en) * 1976-02-10 1977-07-28 Ver Elek Zitaetswerke Westfale DEVICE FOR CATHODIC CORROSION PROTECTION WITH EXTERNAL CURRENT MANODE
US4138323A (en) * 1976-09-29 1979-02-06 Statsenko Nikolai N Apparatus for anodic protection against corrosion of metal objects in contact with electrically conductive media

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57145988A (en) * 1981-03-05 1982-09-09 Mitsubishi Electric Corp Anticorrosive electrode device
WO1993004218A1 (en) 1991-08-14 1993-03-04 Cgr Di Cadignani P.I. Gino Process for mantaining a cathodic protection against corrosion and device for carrying out said process
WO1993011279A1 (en) * 1991-11-28 1993-06-10 Cyberdan A/S Electric power distribution system for active cathodic protection of reinforced concrete constructions
AU656639B2 (en) * 1991-11-28 1995-02-09 Cyberdan A/S Electric power distribution system for active cathodic protection of reinforced concrete constructions
EP0565192A1 (en) * 1992-04-07 1993-10-13 Franciscus Brummelhuis Arrangement for cathodic protection
CN101790339B (en) * 2007-08-31 2012-03-28 Bsh博世和西门子家用器具有限公司 Method for manufacturing a water-bearing domestic appliance
WO2009027402A1 (en) * 2007-08-31 2009-03-05 BSH Bosch und Siemens Hausgeräte GmbH Method for manufacturing a water-bearing domestic appliance
US8783272B2 (en) 2007-08-31 2014-07-22 Bsh Bosch Und Siemens Hausgeraete Gmbh Method for manufacturing a water-bearing domestic appliance
WO2009116901A1 (en) * 2008-03-19 2009-09-24 Ab Volvo Penta Control of a corrosion protection system
US8226812B2 (en) 2008-03-19 2012-07-24 Ab Volvo Penta Control of a corrosion protection system
WO2009116900A1 (en) * 2008-03-19 2009-09-24 Ab Volvo Penta Control of a corrosion protection system
CN105987283A (en) * 2015-01-28 2016-10-05 上海远动科技有限公司 Cathodic protection remote monitoring device for natural gas pipelines based on an SCAD system
CN104674229A (en) * 2015-03-06 2015-06-03 中国石化管道储运有限公司 Intelligent remote monitoring and regulating system for cathode protection of underground pipelines
DE102017200954A1 (en) 2017-01-20 2018-07-26 BSH Hausgeräte GmbH Washing machine with improved corrosion stability and method of operation
EP3916128A1 (en) * 2020-05-27 2021-12-01 iCor Intelligent Corrosion Control GmbH Cathodic corrosion protection circuit arrangement and measurement assembly for cathodic corrosion protection

Also Published As

Publication number Publication date
DE2916934B1 (en) 1980-08-14
ATE359T1 (en) 1981-11-15
DE3060071D1 (en) 1982-01-14
EP0018522B1 (en) 1981-11-04
DE2916934C2 (en) 1981-05-07

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