US3350288A - Method for corrosion protection - Google Patents

Method for corrosion protection Download PDF

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US3350288A
US3350288A US360000A US36000064A US3350288A US 3350288 A US3350288 A US 3350288A US 360000 A US360000 A US 360000A US 36000064 A US36000064 A US 36000064A US 3350288 A US3350288 A US 3350288A
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cylinder
roller
electrode
uncovered
anode
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Almar-Naess Almar
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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
    • C23F13/005—Anodic protection
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
    • C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
    • C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
    • C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
    • C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
    • C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
    • C23F13/18—Means for supporting electrodes
    • 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
    • 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
    • C25F3/22—Polishing of heavy metals
    • C25F3/24—Polishing of heavy metals of iron or steel

Definitions

  • the present invention relates to a method for corrosion protection and cleaning of a drying roller of a paper-making machine.
  • a high degree of protection of a metal'or a metal alloy against corrosion may be achieved by making the metal electrically negative in relation to the surrounding electrolyte. This is the principle of cathodic corrosion protection.
  • the potential difference may be obtained e.g. by an outside source of potential, or by a more or less permanent anode, such as for example when a buried pipe is protected. It is usually assumed that the magnitude of the potential difference between the metal and the adjacent liquid layer determines the degree of protection obtained.
  • a uniform protection of the surface therefore, means a uniform potential difference, which again means a uniform current density on the surface.
  • a uniform current density on the surface is not always obtainable.
  • the current density is, inter alia, dependent upon the placing of the anode.
  • the anodes may be distributed in any desired manner and there is no difiiculty in obtaining a uniform current density at least as long as the conductivity of the soil is reasonably uniform. If, however, the outside of a ship is to be protected, the anodes are usually distributed along the side of the ship, whereby the current density close to the anode becomes much greater than that further away from it.
  • a wet paper web is brought into contact with the surface of the drying roller at one point and leaves the roller surface at another point remote from the one point, leaving an uncovered roller surface between the one and the other point.
  • the surface of the drying roller is cathodically protected against corrosion and cleaned in accordance with the invention by electrically connecting the drying roller to a negative pole of a direct current source, arranging an electrode in a fixed position with respect to the axis of the drying roller and adjacent a portion of the uncovered roller surface, a gap being defined between the electrode and the uncovered roller surface portion, pressing an electrolyte through this gap, electrically connecting the electrode to a positive pole of the direct current source, and passing a current between the electrode and the uncovered roller surface portion whereby hydrogen gas is evolved on the surface of the drying roller.
  • FIGURE 1 is a schematical vertical section of a drying drum for crystallizing solids
  • FIGURE 2 is a schematical vertical section of a Yankee cylinder of a paper-making machine
  • FIGURE 3 is a vertical section on a larger scale of the anode arrangement 14 of FIGURE 2, and
  • FIGURE 4 shows diagrammatically the relationship between the electric current and the overvoltage obtained and employed according to the invention.
  • a rotating drum which is partly in contact with a liquid, as shown schematically in FIGURE 1, can not be protected readily according to the known cathodic principle, as a current can be passed only through that part of the drum which is submerged in the liquid.
  • FIGURE 1 shows a drum 1 for crystallizing solid materials from a solution 2.
  • the drum is Warm, the liquid evaporates from the surface 3, and the solids 5 are scraped off by the drum by scrapers or doctor knives 4.
  • FIGURE 2 shows how paper web 12 and felt backing 11 at one point is brought into contact with, and at another point remote from the one point leaves, the surface of a Yankee cylinder 10 which may be considered to be a very simple paper-making machine.
  • the paper has a moisture content of about 50% on contacting the cylinder, and the cylinder will be corroded on that area where the paper is wettest. The rate of corrosion depends, inter alia, upon the salt content of the water.
  • an anode 17 is arranged either in the area where the paper and felt come on to the cylinder in a wet condition, e.g. between the pressure rolls 16 (FIG. 2), or preferably on the dry area of the cylinder, e.g. at 14 between two of the doctor knives 13 designed to remove remnants of paper and possible corrosion products from the cylinder.
  • the electrolytical double layer between a metal surface and the adjacent electrolyte may be considered a condenser C connected in parallel to a nonlinear resistance Rv, as shown in FIG. 4 e, in the diagram denotes a constant voltage simulating the equilibrium potential between the metal concerned and the electrolyte, and 1 is the overvoltage.
  • n is defined approximately by Tafels equation:
  • an anode 17 e.g. of platinum
  • anode e.g. of platinum
  • the current density must be adjusted to the cylinder speed, the cylinder material and the acting electrolyte.
  • a corresponding corrosion protection is also achieved if the anode 14 is placed on the dry area of the cylinder between the two knives 13, which is also shown in FIG. 2.
  • a useful anode construction is indicated in FIG. 3.
  • the block 21 is made of some electrically insulating material, 22 is the anode. This may consist of platinum, graphite, lead, or other material which is fairly resistant to an anodic load.
  • the cylinder is contaminated by an oxide layer, this will, under certain conditions, be dissolved by the cathodic charge.
  • a cylinder of steel or cast iron for example will normally be coated by a layer of rust wherein the iron is present in the trivalent state, and, therefore, is insoluble in water.
  • the trivalent iron is reduced to the divalent state wherein it is soluble in the anode water and it is consequently removed with this. After some time of operation, such a cylinder will, therefore, be cleaned of rust.
  • the primary electrochemical reaction on the cylinder is hydrogen evolution.
  • the cylinder may be coated electrolytically with a metal layer which is more resistant to corrosion than the base material.
  • the coating may be made very thin, it may be applied during operation of the cylinder, and possible wear, peeling, and the like, may be repaired during operation.
  • the cylinder 25 By making the cylinder 25 the anode in the circuit shown in FIG. 3, and by employing a suitable electrolyte and current density, it is possible to achieve an electrolytic polishing of the cylinder surface. By adjusting the electrolyte and the current density the cylinder-may in this way also be protected anodically against corrosion, i.e. the surface is passivated.
  • An apparatus for corrosion protection and cleaning of the surface of a cylindrical metal drying roller of a paper-making machine comprising (a) the roller,
  • a method for the cathodic corrosion protection and cleaning of a metallic drying roller of a paper-making machine wherein a wet paper web is brought into contact with the surface of the drying roller at one point and leaves the roller surface at another point remote from the one point, leaving an uncovered roller surface between the one and the other point, the steps of (l) arranging an electrode in a fixed position with respect to the axis of the drying roller and adjacent a portion of the uncovered roller surface,

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Paper (AREA)
  • Drying Of Solid Materials (AREA)
  • Rolls And Other Rotary Bodies (AREA)

Description

A. ALMAR-NAEss 3,350,288
METHOD FOR CORROSION PROTECTION Oct. 31, 1967 Filed April 15, 1964 2 Sheets-Sheet 1 INVENTOR. ALMAR ALH AR- Mess BY y MM AGEA United States Patent Office 3,350,288 METHOD FOR CORROSION PROTECTION Almar Almar-Naess, Frydenbergveien 12,
- Trondheim, Norway Filed Apr. 15, 1964, Ser. No. 360,000 Claims priority, application Norway, Apr. 27, 1963,
3 Claims. (Cl. 204-147) ABSTRACT OF THE DISCLOSURE Cathodic protection and cleaning of a drying cylinder of a paper-making machine is achieved by applying a negative charge to the cylinder, fixedly arranging an electrode adjacent a portion of the surface of the cylinder which is not covered by the paper web being dried on the cylinder, applying a positive charge to this electrode, pressing an electrolyte through the gap between the electrode and the cylinder surface, and passing a current between the electrode and this cylinder surface.
The present invention relates to a method for corrosion protection and cleaning of a drying roller of a paper-making machine.
It is known that a high degree of protection of a metal'or a metal alloy against corrosion may be achieved by making the metal electrically negative in relation to the surrounding electrolyte. This is the principle of cathodic corrosion protection. The potential difference may be obtained e.g. by an outside source of potential, or by a more or less permanent anode, such as for example when a buried pipe is protected. It is usually assumed that the magnitude of the potential difference between the metal and the adjacent liquid layer determines the degree of protection obtained. A uniform protection of the surface, therefore, means a uniform potential difference, which again means a uniform current density on the surface.
A uniform current density on the surface is not always obtainable. The current density is, inter alia, dependent upon the placing of the anode. In the cathodic protection of pipes, as mentioned, the anodes may be distributed in any desired manner and there is no difiiculty in obtaining a uniform current density at least as long as the conductivity of the soil is reasonably uniform. If, however, the outside of a ship is to be protected, the anodes are usually distributed along the side of the ship, whereby the current density close to the anode becomes much greater than that further away from it.
In paper making, a wet paper web is brought into contact with the surface of the drying roller at one point and leaves the roller surface at another point remote from the one point, leaving an uncovered roller surface between the one and the other point. The surface of the drying roller is cathodically protected against corrosion and cleaned in accordance with the invention by electrically connecting the drying roller to a negative pole of a direct current source, arranging an electrode in a fixed position with respect to the axis of the drying roller and adjacent a portion of the uncovered roller surface, a gap being defined between the electrode and the uncovered roller surface portion, pressing an electrolyte through this gap, electrically connecting the electrode to a positive pole of the direct current source, and passing a current between the electrode and the uncovered roller surface portion whereby hydrogen gas is evolved on the surface of the drying roller.
The invention is described with reference to the accompanying drawing in which,
3,358,288 Patented Oct. 31, 1967 FIGURE 1 is a schematical vertical section of a drying drum for crystallizing solids,
FIGURE 2 is a schematical vertical section of a Yankee cylinder of a paper-making machine,
FIGURE 3 is a vertical section on a larger scale of the anode arrangement 14 of FIGURE 2, and
FIGURE 4 shows diagrammatically the relationship between the electric current and the overvoltage obtained and employed according to the invention.
A rotating drum which is partly in contact with a liquid, as shown schematically in FIGURE 1, can not be protected readily according to the known cathodic principle, as a current can be passed only through that part of the drum which is submerged in the liquid.
FIGURE 1 shows a drum 1 for crystallizing solid materials from a solution 2. The drum is Warm, the liquid evaporates from the surface 3, and the solids 5 are scraped off by the drum by scrapers or doctor knives 4.
A corresponding problem arises if it is desired to employ cathodic protection for cylinders for drying paper. FIGURE 2 shows how paper web 12 and felt backing 11 at one point is brought into contact with, and at another point remote from the one point leaves, the surface of a Yankee cylinder 10 which may be considered to be a very simple paper-making machine. The paper has a moisture content of about 50% on contacting the cylinder, and the cylinder will be corroded on that area where the paper is wettest. The rate of corrosion depends, inter alia, upon the salt content of the water.
In the method according to the invention, an anode 17 is arranged either in the area where the paper and felt come on to the cylinder in a wet condition, e.g. between the pressure rolls 16 (FIG. 2), or preferably on the dry area of the cylinder, e.g. at 14 between two of the doctor knives 13 designed to remove remnants of paper and possible corrosion products from the cylinder.
As known, the electrolytical double layer between a metal surface and the adjacent electrolyte may be considered a condenser C connected in parallel to a nonlinear resistance Rv, as shown in FIG. 4 e, in the diagram denotes a constant voltage simulating the equilibrium potential between the metal concerned and the electrolyte, and 1 is the overvoltage. n is defined approximately by Tafels equation:
E dn+10 1 (1 La b C z 10 According to this equation the overvoltage will vary principally as shown in FIG. 4 on switching the current on, and off. It will be seen that the overvoltage remains on the surface for some time after the current has been interrupted, which again means that the metal surface is protected against corrosion for some time after the interruption of the current. This after-effect period is in the first instance dependent upon the employed current density, and also, as appears from the equation above, upon the constants a and b, and the capacity C of the double layers. Measured values of these quantities show that in a neutral electrolyte such as 0.21% NaCl in water, corrosion resistance is obtained for about 60 seconds after the current interruption at a current density of about 0.1 amp./cm.
When, an anode 17, e.g. of platinum, is arranged on cylinder 10, pressing against the felt 11 between the two pressure rolls 16, so that the applied current passes the wet felt and wet paper, the whole cylinder will be protected against corrosion. The current density must be adjusted to the cylinder speed, the cylinder material and the acting electrolyte. A corresponding corrosion protection is also achieved if the anode 14 is placed on the dry area of the cylinder between the two knives 13, which is also shown in FIG. 2. A useful anode construction is indicated in FIG. 3. The block 21 is made of some electrically insulating material, 22 is the anode. This may consist of platinum, graphite, lead, or other material which is fairly resistant to an anodic load. Between the anode 22 and the cylinder 25 water 23, 24 having sufiicient electrical conductivity, is passed, so that current may pass between them and establish an electrolytic double layer on the surface of the cylinder. If the cylinder is warm, the water will no doubt evaporate therefrom, so that it is dry outside the block 21. It has, however, been found that an overvoltage may still be measured on the cylinder surface at the place where the wet paper and felt come on to the cylinder, or at any other place where the cylinder is moist and a potential measurement is possible. The reason for this fact is at the present not entirely clear. As the double layer is connected with an electrolyte, it is difficult to realize how it can continue to exist when the electrolyte has evaporated. It may be guessed that the apparently dry cylinder surface is still covered by a layer of water molecules. It may also be assumed that the double layer is formed between the metal and a thin layer of metal oxide, or that an ion migration takes place in the oxide layer so that the equilibrium potential is changed. The invention is, however, not limited to any specific theory.
If the cylinder is contaminated by an oxide layer, this will, under certain conditions, be dissolved by the cathodic charge. A cylinder of steel or cast iron, for example will normally be coated by a layer of rust wherein the iron is present in the trivalent state, and, therefore, is insoluble in water. By a cathodic charge the trivalent iron is reduced to the divalent state wherein it is soluble in the anode water and it is consequently removed with this. After some time of operation, such a cylinder will, therefore, be cleaned of rust.
The primary electrochemical reaction on the cylinder is hydrogen evolution. The hydrogen loosens burnt-on paper remnants from the cylinder, and they are carried away with the anode water. This action is of great importance for a clean cylinder surface, as the fiber and paper remnants can not always be removed by the ordinary scrapers.
If a suitable metal electrolyte is used instead of water between the cylinder and anode, the cylinder may be coated electrolytically with a metal layer which is more resistant to corrosion than the base material. The coating may be made very thin, it may be applied during operation of the cylinder, and possible wear, peeling, and the like, may be repaired during operation.
By making the cylinder 25 the anode in the circuit shown in FIG. 3, and by employing a suitable electrolyte and current density, it is possible to achieve an electrolytic polishing of the cylinder surface. By adjusting the electrolyte and the current density the cylinder-may in this way also be protected anodically against corrosion, i.e. the surface is passivated.
It will be appreciated that the foregoing description is only illustrative of the present invention and it is intended that his invention be limited only by the hereinafter appended claims.
I claim:
1. An apparatus for corrosion protection and cleaning of the surface of a cylindrical metal drying roller of a paper-making machine, comprising (a) the roller,
(b) a container open on one side,
(1) the container being arranged water-tightly against the surface of said roller, with the open container side facing the surface,
(c) an electrode in said container and spaced from the surface,
(d) means for passing an electrolyte into and out of the container; and
(e) means for passing a direct current between the electrode as the anode and the roller as the cathode.
2. A method for the cathodic corrosion protection and cleaning of a metallic drying roller of a paper-making machine, wherein a wet paper web is brought into contact with the surface of the drying roller at one point and leaves the roller surface at another point remote from the one point, leaving an uncovered roller surface between the one and the other point, the steps of (l) arranging an electrode in a fixed position with respect to the axis of the drying roller and adjacent a portion of the uncovered roller surface,
(a) a gap being defined between the electrode and the uncovered roller surface portion,
(2) passing an electrolyte through said gap,
(3) passing a direct current between said electrode as the anode and said uncovered roller surface portion as the cathode.
3. The method of claim 2, further comprising the steps of confining said electrolyte in a chamber, one wall of said chamber being the uncovered roller surface portion and another chamber wall being said electrode, and maintaining a water-tight seal between said chamber and said uncovered roller surface portion.
References Cited UNITED STATES PATENTS 1,746,964 2/1930 Polatsik 204-149 2,847,375 8/1958 Murphy 204197 3,025,790 3/1962 Larsen 10l149.2 3,063,921 11/1962 Leibowitz 2041 10 3,166,487 1/1965 Owren 204196 3,193,450 7/1965 Herbert et al. 162-192 3,196,101 7/1965 Hosford 204l96 3,201,335 8/1965 MacNab et al. 204147 3,231,480 1/1966 Collins 204147 3,242,064 3/1966 Byrne 204196 3,254,012 5/1966 Ziegler 2O4147 FOREIGN PATENTS 449,079 9/1927 Germany.
JOHN H. MACK, Primary Examiner.
T. TUNG, Assistant Examiner.

Claims (1)

  1. 2. A METHOD FOR THE CATHODIC CORROSION PROTECTION AND CLEANING OF A METALLIC DRYING ROLLER OF A PAPER-MAKING MACHINE, WHEREIN A WET PAPER WEB IS BROUGHT INTO CONTACT WITHD THE SURFACE OF THE DRYING ROLLER AT ONE POINT AND LEAVES THE ROLLER SURFACE AT ANOTHER POINT REMOTE FROM THE ONE POINT, LEAVING AN UNCOVERED ROLLER SURFACE BETWEEN THE ONE END AND THE OTHER POINT, THE STEPS OF (1) ARRANGING AN ELECTRODE IN A FIXED POSITION WITH RESPECT TO THE AXIS OF THE DRYING ROLLER AND ADJACENT A PORTION OF THE UNCOVERED ROLLER SURFACE, (A) A GAP BEING DEFINED BETWEEN THE ELECTRODE AND THE UNCOVERED ROLLER SURFACE PORTION, (2) PASSING AN ELECTROLYTE THROUGH SAID GAP, (3) PASSING A DIRECT CURRENT BETWEEN SAID ELECTRODE AS THE ANODE AND SAID UNCOVERED ROLLER SURFACE PORTION AS THE CATHODE.
US360000A 1963-04-27 1964-04-15 Method for corrosion protection Expired - Lifetime US3350288A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4285787A (en) * 1980-03-20 1981-08-25 Pulp And Paper Research Institute Of Canada Electrochemical corrosion protection of stainless steel bleach plant washers
US5068023A (en) * 1987-06-24 1991-11-26 Tapio Toivanen Electrode arrangement
US10273585B2 (en) 2015-06-10 2019-04-30 Westmill Industries Ltd. Cathodic protection for wood veneer dryers and method for reducing corrosion of wood veneer dryers

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4332922A1 (en) * 1993-09-28 1995-03-30 Kloeckner Humboldt Deutz Ag Two-high roller machine and process for the pressure comminution of granular moist material

Citations (12)

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Publication number Priority date Publication date Assignee Title
DE449079C (en) * 1924-11-26 1927-09-01 Siemens Elektrowaerme Ges M B Method and device for heating and drying plastic masses and tissues by means of an electric current
US1746964A (en) * 1926-12-30 1930-02-11 Frederick J Bowers Method of treating waste liquids
US2847375A (en) * 1953-07-13 1958-08-12 Texas Co Apparatus for corrosion prevention
US3025790A (en) * 1956-04-30 1962-03-20 Larsen Carl Ejner Planographic printing method and apparatus
US3063921A (en) * 1957-08-06 1962-11-13 Rand Mines Ltd Method of and apparatus for the electrolytic extraction of gold from a gold-bearing solution
US3166487A (en) * 1962-02-14 1965-01-19 Cranston Print Works Co Cathodic protection of printing apparatus
US3193450A (en) * 1962-04-05 1965-07-06 Johns Manville Method and apparatus for loosening wet pipe from a mandrel
US3196101A (en) * 1962-09-21 1965-07-20 Jr Harry W Hosford Anode support for cathodic protection system
US3201335A (en) * 1962-02-08 1965-08-17 Shell Oil Co Corrosion protection
US3231480A (en) * 1959-07-27 1966-01-25 Sinclair Research Inc Corrosion protection
US3242064A (en) * 1960-02-29 1966-03-22 Engelhard Ind Inc Cathodic protection system
US3254012A (en) * 1962-07-20 1966-05-31 Concrete Thermal Casings Inc Method of cathodically protecting heat-insulated pipes

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE449079C (en) * 1924-11-26 1927-09-01 Siemens Elektrowaerme Ges M B Method and device for heating and drying plastic masses and tissues by means of an electric current
US1746964A (en) * 1926-12-30 1930-02-11 Frederick J Bowers Method of treating waste liquids
US2847375A (en) * 1953-07-13 1958-08-12 Texas Co Apparatus for corrosion prevention
US3025790A (en) * 1956-04-30 1962-03-20 Larsen Carl Ejner Planographic printing method and apparatus
US3063921A (en) * 1957-08-06 1962-11-13 Rand Mines Ltd Method of and apparatus for the electrolytic extraction of gold from a gold-bearing solution
US3231480A (en) * 1959-07-27 1966-01-25 Sinclair Research Inc Corrosion protection
US3242064A (en) * 1960-02-29 1966-03-22 Engelhard Ind Inc Cathodic protection system
US3201335A (en) * 1962-02-08 1965-08-17 Shell Oil Co Corrosion protection
US3166487A (en) * 1962-02-14 1965-01-19 Cranston Print Works Co Cathodic protection of printing apparatus
US3193450A (en) * 1962-04-05 1965-07-06 Johns Manville Method and apparatus for loosening wet pipe from a mandrel
US3254012A (en) * 1962-07-20 1966-05-31 Concrete Thermal Casings Inc Method of cathodically protecting heat-insulated pipes
US3196101A (en) * 1962-09-21 1965-07-20 Jr Harry W Hosford Anode support for cathodic protection system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4285787A (en) * 1980-03-20 1981-08-25 Pulp And Paper Research Institute Of Canada Electrochemical corrosion protection of stainless steel bleach plant washers
US5068023A (en) * 1987-06-24 1991-11-26 Tapio Toivanen Electrode arrangement
US10273585B2 (en) 2015-06-10 2019-04-30 Westmill Industries Ltd. Cathodic protection for wood veneer dryers and method for reducing corrosion of wood veneer dryers
US11193211B2 (en) 2015-06-10 2021-12-07 Westmill Industries Ltd. Cathodic protection for wood veneer dryers and method for reducing corrosion of wood veneer dryers

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FI42491B (en) 1970-04-30
GB1021670A (en) 1966-03-09
DE1521659A1 (en) 1969-10-02

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