US2756204A - Devices for cathodic protection of metallic structures - Google Patents

Devices for cathodic protection of metallic structures Download PDF

Info

Publication number
US2756204A
US2756204A US399362A US39936253A US2756204A US 2756204 A US2756204 A US 2756204A US 399362 A US399362 A US 399362A US 39936253 A US39936253 A US 39936253A US 2756204 A US2756204 A US 2756204A
Authority
US
United States
Prior art keywords
members
strips
length
magnesium
anode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US399362A
Other languages
English (en)
Inventor
William F Higgins
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FA Hughes and Co Ltd
Original Assignee
Hughes & Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hughes & Co filed Critical Hughes & Co
Application granted granted Critical
Publication of US2756204A publication Critical patent/US2756204A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • C23F13/10—Electrodes characterised by the structure
    • 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
    • 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
    • C23F2213/00—Aspects of inhibiting corrosion of metals by anodic or cathodic protection
    • C23F2213/30—Anodic or cathodic protection specially adapted for a specific object
    • C23F2213/31—Immersed structures, e.g. submarine structures

Definitions

  • This invention relates to devices for the cathodic protection of ferrous metallic structures, e. g. piers and pipe lines, against corrosion.
  • Such devices generally consist of an anode of a suitable metal such as magnesium or magnesium alloy connected electrically to the structure, the anode and structure being in contact with a common electrolytic medium e. g. seawater.
  • a common electrolytic medium e. g. seawater.
  • anodic device comprising a plurality of elongated members of metal suitable for sacrificial anodes said members having a length of at least six inches and greater than six times their width, said members being connected closely together at one part of their length and extending away from the position of connection in directions diverging from each other or being deformable into such diverging directions whereby a strong interference effect is produced when the device is connected to said structure in the electrolyte.
  • the invention also includes a protective system com- PllSlllg a ferrous metal structure immersed in an aqueous electrolyte and a plurality of elongated members immersed in said electrolyte and in connection with said structure, said members being made of a metal suitable for sacrificial anodes and having a length of at least six inches and greater than six times their width, and connected so close together as to cause a strong interference eifect between but diverging from each other progressively from the position of their connection together.
  • At and adjacent the positions of attachment to each other distance apart of the members may be from nil up to a distance equal to ten per cent (or in special cases up to fifty per cent) of the distance from their position of attachment to their outer edge.
  • each pair of adjacent strips are curved so as to be at a progressively increasing distance from each other from the centre to their outer free ends on one or both sides of their position of connection together where the strips are in contact with each other.
  • the strips or plates may have a thickness of 0.020" to 2".
  • the strips may have a length of 6 to 36 times (e. g. 6 to 16 times) the width, e. g. a length of 6 to 72 inches and a width of 0.5 to 12 inches. If wires are used in place of strips they may have a minimum width (thickness) of 0.05 inch.
  • the effect When immersed in an electrolyte the effect is that the divergent ends interfere little with each other, current generation is high, and metal consumption rapid in conse quence. Further along the strips, towards the central mass, the interference effect becomes more and more pronounced so that less current is generated in this region and less corrosion occurs. Hence the output of the anode is controlled and the device is forced to corrode from the outside edges inwards, which is the effect desired.
  • the interference eliect is an elfect resulting from the generation of current and only occurs when the anode is attached to the cathode and current is flowing. it is not due merely to the reduced volume of electrolyte in the narrow angles between the strips. If magnesium alloy strips are immersed in a corrosive electrolyte, disposed as in the anode described but not connected to any cathode, then no interference effect is observed and the strips corrode as they would have done had they been immersed individually.
  • Figure l is a perspective view of an anodic device made in accordance with the invention.
  • Figure 2 is a front view of the device when deformed ready for use
  • Figure 3 is a side view of the device connected to a ferrous structure to be protected.
  • Figure 4 is a view of a modified construction.
  • two bundles of rolled or extruded strips 10 of magnesium base alloy are surrounded at and adjacent their middle positions with a wrapping 11, 12 of zinc or aluminium foil or sheet.
  • zinc and aluminium we mean either the pure metals or alloys constituted to at least 85 per cent by these metals.
  • the major length of each end of the bundle protrudes from the wrapping and the protruding ends are each at least six inches in length and at least six times their width.
  • Two or more holes are drilled through the thickness of the strips and the zinc or aluminium wrapping, and the anodes, when installed, are attached to a supporting bar or wire rope 14, or any suitable connection to the cathode, by securing the two bundles together with the wire rope clamped between them by means of bolts 15, 16 through the aforesaid holes.
  • the bar or the like 14 is screwed into or otherwise connected to the ferrous structure 18 ( Figure 3) to be protected.
  • a clamping nut 19 may be used to prevent inadvertent unscrewing of the bar.
  • the invention enables the spacing of the strips, plates or discs of which the composite anode is made to be regulated at the time of assembly or installation to suit varying requirements of galvanic protection while using a few standard components.
  • the blades or projecting strips of the bundles first described can be bent out into fan shape structures (as shown in Figure 2) of diiferent angle, during actual installation, to provide a varying degree of cathodic protection on the one hand, or of duration of efiect on theother hand.
  • anode membets are in the form of wires welded or otherwise fixed together at one end 21.
  • the welding or other fixing may be disposed at some other position along the wires.
  • Zinc may be wrapped around the weld to avoid attack on the weld and wires at and adjacent the weld. Any suitable bolt, clamp or the like can be used for attaching the device to the structure to be protected.
  • a device for the protection of ferrous metal structures immersed in an aqueous electrolyte against corrosion comprising a plurality of elongated members of metal suitable for sacrificial anodes of the class consisting of magnesium and magnesium alloys, said members having a length of at least six inches and greater than six times their width, said members being connected closely together at one part of their length by a body of zinc parallel to each other and extending away from the 'pOSiw tion of connection parallel to each other, said members being deformable by bending into directions diverging from each other whereby a strong interference effect is produced when the device is connected to said structure in the electrolyte.
  • a device for the protection of ferrous metal structures immersed in an aqueous electrolyte against corrosion comprising a plurality of separate strips of wrought magnesium, connected together at their middle positions where they are parallel to each other with a wrapping of zinc metal and having a length on each side of the position of connection of at least six inches and greater than six times their width, said strips being deformable by bending into directions diverging from each other whereby a strong interference eltect is produced when the device is connected to said structure in the electrolyte.
  • a device for the protection of ferrous metal structures immersed in an aqueous electrolyte against corrosion comprising a plurality of separate strips of magnesium base alloy, connected together at their middle positions where they are parallel to each other and having a length on each side of the position of connection of at least six inches and greater than six times their width, said strips being deformable by bending into directions diverging from each other whereby a strong interference effect is produced when the device is connected to said structure in the electrolyte, a metal element for attachment to said structure and connected to said strips, and sheet wrapping made of a metal selected from the group consisting of zinc and aluminium, said wrapping being wrapped around said strips at and adjacent their position of connection to said element.
  • a device for the protection of ferrous metal structures immersed in an aqueous electrolyte against corrosion comprising a plurality of elongated members of metal suitable for sacrificial anodes of the class consisting of magnesium and magnesium base alloys, said members having a length of at least six inches and greater than six times their width, said members being connected closely together at one part of their length parallel to each other and extending away from the position of connection parallel to each other, said members being deformable by bending into directions diverging from each other whereby a strong interference efiect is produced when the device is connected to said structure in the electrolyte; said members being in the form of wires Welded together at their ends and a wrapping of zinc around the welded ends of the wires.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Prevention Of Electric Corrosion (AREA)
US399362A 1953-01-27 1953-12-21 Devices for cathodic protection of metallic structures Expired - Lifetime US2756204A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2320/53A GB733817A (en) 1953-01-27 1953-01-27 Improvements in or relating to devices for the cathodic protection of metallic structures

Publications (1)

Publication Number Publication Date
US2756204A true US2756204A (en) 1956-07-24

Family

ID=9737479

Family Applications (1)

Application Number Title Priority Date Filing Date
US399362A Expired - Lifetime US2756204A (en) 1953-01-27 1953-12-21 Devices for cathodic protection of metallic structures

Country Status (5)

Country Link
US (1) US2756204A (en(2012))
BE (1) BE525809A (en(2012))
DE (1) DE973861C (en(2012))
FR (1) FR1091557A (en(2012))
GB (1) GB733817A (en(2012))

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3179582A (en) * 1961-07-26 1965-04-20 Herman S Preiser Welding attachment of anodes for cathodic protection
US3486999A (en) * 1967-11-02 1969-12-30 Leonard F Craft Apparatus for preventing scale formation in water systems
US4298445A (en) * 1977-05-09 1981-11-03 Marston Excelsior Limited Anode for cathodic protection system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB190611216A (en) * 1906-05-14 1907-02-21 Donald Barns Morison Improvements in and relating to Apparatus for Preventing or Lessening the Corrosion of Condenser Tubes.

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2404031A (en) * 1943-06-18 1946-07-16 Standard Oil Dev Co Corrosion preventing electrode

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB190611216A (en) * 1906-05-14 1907-02-21 Donald Barns Morison Improvements in and relating to Apparatus for Preventing or Lessening the Corrosion of Condenser Tubes.

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3179582A (en) * 1961-07-26 1965-04-20 Herman S Preiser Welding attachment of anodes for cathodic protection
US3486999A (en) * 1967-11-02 1969-12-30 Leonard F Craft Apparatus for preventing scale formation in water systems
US4298445A (en) * 1977-05-09 1981-11-03 Marston Excelsior Limited Anode for cathodic protection system

Also Published As

Publication number Publication date
BE525809A (en(2012))
GB733817A (en) 1955-07-20
FR1091557A (fr) 1955-04-13
DE973861C (de) 1960-06-30

Similar Documents

Publication Publication Date Title
DE1281232B (de) Anode fuer den kathodischen Korrosionsschutz
US2756204A (en) Devices for cathodic protection of metallic structures
US2826543A (en) Mounting means for cathodic protection anodes
US3001924A (en) Sacrificial magnesium anodes
US4187164A (en) Anode
US3726779A (en) Marine anticorrosion anode structure
US3635813A (en) Anode system for cathodic protection of stretched chain
US3232857A (en) Cathodic protection anode structure
GB765085A (en) Improvements in or relating to cathodic protections of metal structures
US3019177A (en) Cathodic protection anode assembly
US2772231A (en) Anodes for the protection of metal structures against corrosion
JP2534329Y2 (ja) 防食用ボルトとボルトの防食用金具
US4298445A (en) Anode for cathodic protection system
US3179582A (en) Welding attachment of anodes for cathodic protection
JP2615863B2 (ja) 電解用陰極板
US3041266A (en) Fluorine cell anode assembly
US4468310A (en) Aluminum marine anode with core activator
US3376209A (en) Anode formed of lead base and duriron
CN112877699A (zh) 一种基于霍尔效应的金属防腐蚀装置
JP3798189B2 (ja) コンクリート構造物の補修方法
US4191625A (en) Aluminum marine anode assembly with low resistance surface mountings
ES300786A1 (es) Procedimiento para la fabricaciën de un conductor electrico
JPH0645687Y2 (ja) ボルトの防食用金具
JP2644591B2 (ja) 電気化学的防蝕部材
CN213008622U (zh) 一种船舶防腐绝缘接地穿舱件