US3342716A - Anode for cathodic protection system - Google Patents

Anode for cathodic protection system Download PDF

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Publication number
US3342716A
US3342716A US374705A US37470564A US3342716A US 3342716 A US3342716 A US 3342716A US 374705 A US374705 A US 374705A US 37470564 A US37470564 A US 37470564A US 3342716 A US3342716 A US 3342716A
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US
United States
Prior art keywords
rod
support member
anode
rods
hull
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
US374705A
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English (en)
Inventor
Edward P Anderson
Samuel P Crago
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.)
BASF Catalysts LLC
Engelhard Industries Inc
Original Assignee
Engelhard Industries Inc
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
Priority to NL125196D priority Critical patent/NL125196C/xx
Application filed by Engelhard Industries Inc filed Critical Engelhard Industries Inc
Priority to US374705A priority patent/US3342716A/en
Priority to SE7652/65A priority patent/SE316964B/xx
Priority to BE665310D priority patent/BE665310A/xx
Priority to DEE29494A priority patent/DE1272681B/de
Priority to NO158455A priority patent/NO115508B/no
Priority to GB24897/65A priority patent/GB1063406A/en
Priority to FR20416A priority patent/FR1459791A/fr
Priority to DK294265AA priority patent/DK116107B/da
Priority to NL6507495A priority patent/NL6507495A/xx
Application granted granted Critical
Publication of US3342716A publication Critical patent/US3342716A/en
Assigned to ENGELHARD CORPORATION reassignment ENGELHARD CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: PHIBRO CORPORATION, A CORP. OF DE
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • C23F13/20—Conducting electric current to electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
    • B03B1/00—Conditioning for facilitating separation by altering physical properties of the matter to be treated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B59/00—Hull protection specially adapted for vessels; Cleaning devices specially adapted for vessels
    • 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
    • C23F13/16—Electrodes characterised by the combination of the structure and the material
    • 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

  • the present invention relates to an anode adapted for use in impressed current cathodic protection systems for preventing corrosion of large metal surfaces under water such as the hulls of ships.
  • Impressed current cathodic protection systems are used on the submerged portions of ships hulls to reduce or eliminate corrosion of the metal of the hull.
  • Metal in water is corroded by the flow of positive ions away from the metal surface toward more negatively charged areas. This galvanic process of corrosion is halted by impressing a charge on the bull to render it more negatively charged.
  • conventional current cathodic protection systems the negative potential of the hull is built up by means of anodes mounted on the submerged portions of the hull structure. The anodes are electrically insulated from the hull and a source of direct current electric power is connected to the anodes and the hull in a manner to be able to adjust the potential of the hull by regulating the voltage applied to the anodes.
  • An additional object is to provide such an anode which is of simple, rugged and economical construction and which is mounted easily and inexpensively on a ships hull.
  • anodes In cathodic protection systems the anodes are normally mounted on the surface to be protected as a matter of convenience and they are, of course, insulated from direct contact with the surface.
  • the anodes are therefore conventionally formed of an electrically conductive metal surface on an electrically insulating support with the insulating support attached to the hull.
  • the voltage applied to the anodes is desirably such as to project a protective current for as great an area as possible around each anode.
  • the negative potential built up on the hull will be greatest close to the anode.
  • the level of potential impressed on the hull de creases as the distance from the anode increases and the extent of the area of protection around each anode is determined by the amount of voltage applied. But the amount of voltage which can beneficially be applied is limited since too great a negative potential impressed on a portion of the hull will cause paint on that portion to flake olf.
  • Cathodic protection of a large area of submerged surface is conventionally provided by using a number of anodes spaced apart over the submerged area.
  • the hull would normally be pierced at each anode for electrical connection to the source of electric power within the hull.
  • a stufling box or other water-tight seal is required for each connection through the hull and this makes the use of a large number of separate anodes expensive.
  • the location of bulkheads and other obstructions within the hull may make it difficult or impossible to locate anodes in the best positions to provide even protection over the hull.
  • An alternative by which the number of connections through the hull is reduced is to use anodes which are in the form of elongated strips of the conductive metal which is used for the anodic surfaces.
  • the present invention is an anode generally of the strip type but having a novel construction which makes more efficient and economic use of expensive corrosion-resistant metals-such as platinum, palladium and alloys thereof-than previous anode constructions.
  • the anode has a plurality of anodic surfaces spaced apart on the insulating support so that some of the effective anodic surface is further from the electrical connection than if the anodic surface were a continuous strip.
  • the anodic surfaces and insulating support are connected in such a way that the anodic surfaces are firmly anchored and considerably less easily scraped or broken away from the support than with some conventional types of construction, yet the anode has flexibility which enables it to be secured flat against curved surfaces of a ships hull.
  • the anode of this invention comprises generally a rod of electrically conductive metal embedded in an electrical insulating support member with short portions of the rod exposed at intervals along the rod.
  • the support is an elongated block of insulating material such as glass reinforced polyester and the rod is formed. with a plurality of generally U-shaped portions bent up out of the plane of the rod and arranged in the support so that the top part of each U-shaped portion is exposed to provide an anodic surface.
  • a conventional electrical connection through a stufling box is used to connect the rod to the cathodic protection system power supply within the hull.
  • the rod may be made of an electrically conductive metal and in practice is made of tantalum or titanium over a core of copper or aluminum. Since the exposed portions of the rod are subject to chemical attack by the electrolytic decomposition products of sea water they are normally coated with platinum to render them corrosion resistant.
  • two rods are arranged parallel in a single insulating support member and the exposed portions of the rods are in a trough in the top of the support member so as to be below the level of top of the support.
  • the exposed portions of the rods are thus protected from being damaged by underwater floating objects, anchor chains, piers and the like.
  • the support member is generally rectangular in cross section and the anode may be made long and straight, curved or even circular, in which case it resembles a fiat hoop. It may be made up of one long element or of articulated sections joined by male and female connections.
  • FIGURE 1 is a top view of an anode in accordance with the present invention.
  • FIGURE 2 is a section along the line 2-2 of FIG- URE 1;
  • FIGURE 3 is a section along the line 33 of FIG- URE 1;
  • FIGURE 4 is a section along the line 4-4 of FIG- URE 1 showing a suitable stufling box and electrical connector which may be used to connect the anode to a source of electric power within a ships hull;
  • FIGURE 5 is a section along the line 5-5 of FIG- URE 4.
  • the anode of the present invention comprises generally a rod of electrically conductive metal which is embedded in a support member 11 of insulating material with portions 12 of the rod 10 exposed to provide anodic surfaces.
  • the rod 10 is made of titanium or tantalum over a core of copper or aluminum. This combination provides the desired properties of good electrical conductivity, mechanical strength and resistance to corrosion.
  • the portions 12 which are exposed to form the anodic surfaces of the rod 10 are particularly vulnerable to chemical attack by the electrolytic decomposition products of sea Water and are therefore normally plated or sheathed with a layer of platinum or an alloy of platinum or palladium. Tubes of platinum or palladium alloy may he slipped over the rod 10 and swaged in place at the points which will be exposed portions 12 when the rod is embedded in the support member 11.
  • the support member 11 may be made of any suitable insulating material which is resistant to chemical attack from sea water and electrolytic decomposition products.
  • the support member 11 is preferably flexible to an etxent which will permit the length of a support member 11 to be conformed to the curvature of a ships hull so as to be able to secure the entire length of the member 11 fiat against the hull surface.
  • the support member 11 may be made of glass reinforced polyester and may be any shape suitable for supporting the rod 10 with portions 12 of the rod exposed at spaced intervals as illustrated in FIGURE 3.
  • the support member 11 will normally be long and narrow to accommodate a single rod 10 or may be made enough wider to accommodate a pair of parallel rods 10 as shown in FIGURES 1 and 2.
  • the sup-port member is generally rectangular in cross-section with a plurality of countersunk holes 14 through it at spaced intervals along its length to receive studs 15 which will normally be welded to a ships hull 16.
  • the studs 15 extend into the holes 14 with nuts 17 threaded on the ends of the studs as means to attach the support member 11, and hence the anode, to the hull 16.
  • the rods 10 are embedded in the support member 11 so as to leave the portions 12 of the rods exposed at intervals along the length of the rod with the sections of the rods between the portions 12 firmly anchored in the support. This is accomplished by bending a plurality of generally U-shaped portions up out of the plane of the rod and embedding the rod in the support member 11 with the tops of the U-shaped portions exposed to provide the portions 12 which are the anodic surfaces.
  • the exposed portions 12 are in a trough 19 in the support member 11 and are below the level of the surface of the support so as to be protected from being scraped or broken by anchor chains, piers, underwater floating objects and the like.
  • the rods 10 are connected through a connector pin 20 to an electric power supply 21.
  • a single connection to the power supply 21 thus supplies the power for a plurality of spaced-apart anodic surfaces formed by the exposed portions 12 of the rods 10.
  • a second pair of rods 22 may be connected parallel to and below the rods 10 so as to be in contact with them at spaced intervals along the portion of the rods 10 which are completely embedded in the support member 11.
  • the rods 22 are held in contact with the bottoms of the U-shaped portions of the rods 10 by pliable bands 24 wrapped around the rods.
  • the rods 22 serve as bus bars to assure good distribution of power to all the exposed portions 12 along the entire length of the rod 10 and more importantly to provide a by-pass through which electric power will flow to the portions 12 at the ends of the anode if one of the portions 12 intermediate the ends of the anode and the connection to the power source should be severed.
  • the rods 22 add mechanical strength to the anode structure. This is particularly helpful during assembly of the structure when the rods 10 are being embedded in the support member 11.
  • the support member 11 is extruded from a suitable material such as glass reinforced polyester.
  • the trough 19 may be provided for in the extrusion or it may be routed out later.
  • the countersunk holes 14 are drilled and a pair of parallel channels (indicated by dotted lines 26 in FIGURE 2) are routed out to receive the rods 10.
  • the rods 10 are formed to the desired configuration, and, if rods 22 are to be included, the rods 22 are attached by means of bands 24.
  • the rods 10 are set in the channels to the desired depth and a thermoplastic material such as glass-reinforced polyester is heated until it is viscous and packed into the channels around the portions of the rods 10 to be embedded. The plastic is then allowed to cool and harden.
  • Self-curing plastic resin such as polyvinyl chloride are also quite suitable.
  • connection of the rods 10 (and 22) to the power supply 21 is through a connector pin 20.
  • the connector pin 20 may be electrically connected to the rods 10 and 22 by any convenient means such as welding or by a clamping arrangement such as illustrated in FIGURES 4 and 5.
  • the clamping arrangement shown is provided by a flange 28 threaded onto the upper portion of the connector pin 20.
  • a pair of lugs 29 project upward from opposite edges of the flange 28 and as best seen in FIGURE 5 the portions of the rods 10 and 22 adjacent the connector pin 20 are bent inward and passed around the lugs 29 which thus hold the rods across the flange 28.
  • the rods are held clamped against the flange 28 by a nut 30 and Washer 31.
  • the washer 31 rests on top of the rods 10 and 22 and is held down by the nut 30 which is threaded onto the connector pin 20.
  • the bottom of the pin 20 extends out through a cylindrical boss or stem 33 on the bottom of the support member 11.
  • the stem 33 is sealed through the hull 16 in a manner described below and the connector pin 20 extends inside the hull 16.
  • a female connector 34 fitting on the end of the connector pin 20 is on the end of a conductor 35 which is connected to the positive terminal of the power supply 21.
  • the negative terminal of the power supply is connected to the hull 16 through suitable connections as indicated in FIGURE 4 by a conductor 36 to the hull 16.
  • the seal for the conection through the hull 16 may be formed in any conventional manner. As shown in FIG- URE 4 the seal is conveniently formed by sleeve 38 welded into a bore through the hull.
  • the cylindrical stem 33 of the support member 11 fits snugly into the sleeve 38 which is counterbored as shown to provide space for compression packing rings 39 between the inside of the sleeve 38 and the stem 33.
  • a jam nut 40 having an aperture 41 through the end for the connector pin 20 and female connector 34 is threaded on the sleeve 38 to compress the packing rings 39 and complete the seal.
  • An anode assembly for use in a cathodic protection system for underwater metal structures comprising, a support member of electric insulating material, a rod of electrically conductive metal, said rod being embedded in the support member with portions of the rod exposed outside the support member at spaced intervals along the length of the rod, and means for supplying electric power to the rod, said means including a second rod of electrically conductive metal completely embedded in the support member parallel to and in contact wtih the first mentioned rod.
  • An anode assembly for use in a cathodic protection system for underwater metal structures comprising, an
  • a rod of electrically conductive metal having a plurality of generally U-shaped portions bent up out of the plane of the rod, said rod being anchored and embedded in the support member with top parts of the U-shaped portions exposed outside the support member, and means for supplying electric power to the rod.
  • An anode assembly according to claim 2 including a second rod of electrically conductive metal complete-1y embedded in the support member parallel to and in contact with the first mentioned rod.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • Ocean & Marine Engineering (AREA)
  • Prevention Of Electric Corrosion (AREA)
US374705A 1964-06-12 1964-06-12 Anode for cathodic protection system Expired - Lifetime US3342716A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
NL125196D NL125196C (no) 1964-06-12
US374705A US3342716A (en) 1964-06-12 1964-06-12 Anode for cathodic protection system
SE7652/65A SE316964B (no) 1964-06-12 1965-06-10
DEE29494A DE1272681B (de) 1964-06-12 1965-06-11 Anodenanordnung fuer den kathodischen Schutz in Wasser eintauchender metallischer Gegenstaende
NO158455A NO115508B (no) 1964-06-12 1965-06-11
GB24897/65A GB1063406A (en) 1964-06-12 1965-06-11 Anode for cathodic protection system
BE665310D BE665310A (no) 1964-06-12 1965-06-11
FR20416A FR1459791A (fr) 1964-06-12 1965-06-11 Anode pour système de protection cathodique
DK294265AA DK116107B (da) 1964-06-12 1965-06-11 Uopløselig anode til anvendelse i katodisk beskyttende systemer.
NL6507495A NL6507495A (no) 1964-06-12 1965-06-11

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US374705A US3342716A (en) 1964-06-12 1964-06-12 Anode for cathodic protection system

Publications (1)

Publication Number Publication Date
US3342716A true US3342716A (en) 1967-09-19

Family

ID=23477882

Family Applications (1)

Application Number Title Priority Date Filing Date
US374705A Expired - Lifetime US3342716A (en) 1964-06-12 1964-06-12 Anode for cathodic protection system

Country Status (8)

Country Link
US (1) US3342716A (no)
BE (1) BE665310A (no)
DE (1) DE1272681B (no)
DK (1) DK116107B (no)
GB (1) GB1063406A (no)
NL (2) NL6507495A (no)
NO (1) NO115508B (no)
SE (1) SE316964B (no)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2396810A1 (fr) * 1977-07-08 1979-02-02 Marston Excelsior Ltd Element anodique pour protection cathodique
US5389223A (en) * 1988-07-23 1995-02-14 Robert Bosch Gmbh Electrochemical measuring sensor
WO2007102021A3 (en) * 2006-03-07 2007-12-27 Gareth Glass Electrical connection to impressed current anode in concrete construction

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3019177A (en) * 1959-01-08 1962-01-30 Engelhard Ind Inc Cathodic protection anode assembly
US3022242A (en) * 1959-01-23 1962-02-20 Engelhard Ind Inc Anode for cathodic protection systems

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB719427A (en) * 1952-08-05 1954-12-01 Hughes & Co Improvements in or relating to the cathodic protection of metallic structures against corrosion in sea-water
GB932710A (en) * 1958-04-28 1963-07-31 Engelhard Ind Inc Anode assembly for cathodic protection systems
GB927232A (en) * 1958-08-11 1963-05-29 Central Electr Generat Board Improvements in devices for cathodic protection of metallic parts

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3019177A (en) * 1959-01-08 1962-01-30 Engelhard Ind Inc Cathodic protection anode assembly
US3022242A (en) * 1959-01-23 1962-02-20 Engelhard Ind Inc Anode for cathodic protection systems

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2396810A1 (fr) * 1977-07-08 1979-02-02 Marston Excelsior Ltd Element anodique pour protection cathodique
US4187164A (en) * 1977-07-08 1980-02-05 Marston Excelsior Limited Anode
US5389223A (en) * 1988-07-23 1995-02-14 Robert Bosch Gmbh Electrochemical measuring sensor
WO2007102021A3 (en) * 2006-03-07 2007-12-27 Gareth Glass Electrical connection to impressed current anode in concrete construction
GB2448850A (en) * 2006-03-07 2008-10-29 Gareth Kevin Glass Electrical connection to impressed current anode in concrete construction
US20090032410A1 (en) * 2006-03-07 2009-02-05 Gareth Kevin Glass Electrical connection to impressed current anode in concrete construction
US7967972B2 (en) 2006-03-07 2011-06-28 Gareth Kevin Glass Electrical connection to impressed current anode in concrete construction

Also Published As

Publication number Publication date
GB1063406A (en) 1967-03-30
NL125196C (no)
NL6507495A (no) 1965-12-13
SE316964B (no) 1969-11-03
NO115508B (no) 1968-10-14
DE1272681B (de) 1968-07-11
BE665310A (no) 1965-12-13
DK116107B (da) 1969-12-08

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AS Assignment

Owner name: ENGELHARD CORPORATION 70 WOOD AVENUE SOUTH, METRO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:PHIBRO CORPORATION, A CORP. OF DE;REEL/FRAME:003968/0801

Effective date: 19810518