Ferrous Metal Patents (Class 205/731)
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Patent number: 9314818Abstract: A superhydrophobic surface includes a plurality of microfeatures disposed on a substrate and a gas generator disposed within the microfeatures, the gas generator configured to generate a gas within the microfeatures. Gas is generated within the microfeatures when at least a portion of the microfeatures is in a wetted state to restore the microfeatures to a dewetted state. Gas generation is self-regulating in that gas generation automatically starts when a wetted condition exists and stops when sufficient gas has been generated to recover a dewetted state that restores superhydrophobicity.Type: GrantFiled: July 22, 2011Date of Patent: April 19, 2016Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Chang-Jin Kim, Choongyeop Lee
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Publication number: 20150053573Abstract: A method of mitigating galvanic corrosion on a vehicle is provided for use of metals with carbon containing composites. An electrically conductive material comprising a plurality of electrically conductive metallic particles and a polymer is applied to a corrosion susceptible region of an assembly having a carbon-reinforced composite and a metal. The electrically conductive material has an electrical conductivity of greater than or equal to about 1×10?4 S/m and serves as a sacrificial anode to mitigate or prevent corrosion of the metal in the assembly. Also provided are assemblies for a vehicle having reduced galvanic corrosion that include a metal component in contact with a carbon-reinforced composite, which defines a corrosion susceptible region having an electrically conductive material disposed therein.Type: ApplicationFiled: August 22, 2013Publication date: February 26, 2015Applicant: GM Global Technology Operations LLCInventors: Hamid G. Kia, William R. Rodgers
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Patent number: 8679303Abstract: A liquid heating system may comprise a metallic container and a refillable non-corrosive hollow porous tube, which may be coupled to the metallic container. The refillable non-corrosive hollow porous tube may include at least one open end and anodic material may be filled or refilled into the refillable non-corrosive hollow porous tube through the at least one open end. The anodic material is corroded by the oxidation process at a substantially faster rate compared to the metallic container. The anodic material is refilled into the refillable non-corrosive hollow porous tube through the at least one open end without removing the refillable non-corrosive hollow porous tube from the metallic container or disturbing the position of the refillable non-corrosive hollow porous tube.Type: GrantFiled: November 14, 2009Date of Patent: March 25, 2014Assignee: Airgenerate, LLCInventor: Sunil Kumar Sinha
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Patent number: 8273239Abstract: An electric field modifier for boosting a current output of a sacrificial anode to enhance its protective effect and direct the current output to improve current distribution in galvanic protection of steel in a concrete element exposed to air is disclosed. A cavity is formed in a concrete element and a combination comprising a sacrificial anode, an electric field modifier and an ionically conductive filler are embedded therein. The sacrificial anode is connected to the steel. The modifier comprises an element with an anode side, supporting an oxidation reaction, in electrical contact with a cathode side, supporting a reduction reaction. The cathode of the modifier faces the sacrificial anode and is separated therefrom by a filler which contains an electrolyte that connects the sacrificial anode to the cathode of the modifier. The anode of the modifier faces away from the sacrificial anode. Preferably, the reduction reaction, on the cathode of the modifier, comprises reduction of oxygen from the air.Type: GrantFiled: June 11, 2010Date of Patent: September 25, 2012Inventors: Gareth Kevin Glass, Adrian Charles Roberts, Nigel Davison
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Patent number: 8163159Abstract: Techniques generally describe articles of enclosing manufacture and methods related to containers including a magnesium sacrificial anode for corrosion protection. Example articles of enclosing manufacture may include a liner or a rod that is configured as a sacrificial anode to protect a metallic side or end wall of the enclosing manufacture from corrosion. Other embodiments may be disclosed and claimed.Type: GrantFiled: November 25, 2009Date of Patent: April 24, 2012Assignee: Empire Technology Development LLCInventor: Angele Sjong
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Patent number: 8137528Abstract: This invention relates to protection of a metal component exposed to a corroding medium. One or more of the following are provided: cathodic protection, measuring of a condition of the component, retarding or avoiding of fouling. A sacrificial anode is used as the energy source such that the electric circuit can provide a pulsating current, voltage, automatically adapted current, or protecting potential. Germanium solid state elements are used.Type: GrantFiled: May 1, 2007Date of Patent: March 20, 2012Inventor: Johannes Jacobus Maria Heselmans
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Patent number: 7951286Abstract: A method is disclosed for using an impressed current cathodic protection (ICCP) system that supplies an electrical current such that a metallic structure (10) has a negative voltage of between 0.5 and 1.5 Volt relative to earth to power one or more electrical appliances (5), the method comprising: —providing one or more electrical appliances (5) which each have a pair of electrical contacts (1,2); —connecting one electrical contact (1) of each electrical appliance to the structure; and —connecting the other electrical contact (2) of each electrical appliance to earth, thereby providing electrical power to each of the electrical appliances. It is preferred that the electrical appliances (5) are equipped with one or more DC-DC power converters (6) which are configured to enhance an electrical input voltage of between 0.5 and 1.5 Volt to an electrical output voltage of between 3 and 5 Volt.Type: GrantFiled: April 20, 2007Date of Patent: May 31, 2011Assignee: Shell Oil CompanyInventors: Sicco Dwars, Christopher Ozemoya Ubuane
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Patent number: 7914661Abstract: Cathodic protection of a structure including a steel member at least partly buried in a covering layer, such as steel rebar in a concrete structure, is provided by embedding sacrificial anodes into the concrete layer at spaced positions over the layer and connecting the anodes to the rebar. The anode body is formed, by pressing together finely divided powder, flakes or fibers of a sacrificial anode material such as zinc to define a porous body having pores therein. The sacrificial anode material of the anode member is directly in contact with the covering material by being buried or inserted as a tight fit into a drilled hole so that any expansion forces therefrom would be applied to the concrete with the potential of causing cracking. The pores are arranged however such that corrosion products from corrosion of the anode body are received into the pores sufficiently to prevent expansion of the anode body to an extent which would cause cracking of the covering material.Type: GrantFiled: September 12, 2007Date of Patent: March 29, 2011Inventor: David Whitmore
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Patent number: 7909982Abstract: A single anode system used in multiple electrochemical treatments to control steel corrosion in concrete comprises a sacrificial metal that is capable of supporting high impressed anode current densities with an impressed current anode connection detail and a porous embedding material containing an electrolyte. Initially current is driven from the sacrificial metal [1] to the steel [10] using a power source [5] converting oxygen and water [14] into hydroxyl ions [15] on the steel and drawing chloride ions [16] into the porous material [2] around the anode such that corroding sites are moved from the steel to the anode restoring steel passivity and activating the anode. Cathodic prevention is then applied. This is preferably sacrificial cathodic prevention that is applied by disconnecting the power source and connecting the activated sacrificial anode directly to the steel.Type: GrantFiled: March 14, 2006Date of Patent: March 22, 2011Inventors: Gareth Glass, Adrian Roberts, Nigel Davison
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Patent number: 7897031Abstract: An apparatus, system, method and computer program product directed to controlling corrosion, particularly space weather induced corrosion, of a conductive structure in contact with a corrosive environment and coated with a semiconductive coating, where the corrosion is controlled by a controllable filter and a corresponding electronic control unit configured to process and adjust the controllable filter in response to at least one measured parameter associated with space weather effects on the conductive structure.Type: GrantFiled: November 18, 2008Date of Patent: March 1, 2011Assignee: Applied Semiconductor International Ltd.Inventors: David B. Dowling, Farshad Khorrami, Joseph G. Michels, Mikhail Panasyuk
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Patent number: 7851022Abstract: The invention relates to a galvanic anode system for the corrosion protection of steel, comprised of a solid electrolyte and a galvanic anode material, preferably zinc and its alloys, glued to the solid electrolyte or embedded in the solid electrolyte. The solid electrolyte is characterised by a high ion conductivity and comprises at least one anionic and/or cationic polyelectrolyte and/or preferably at least one compound that forms complex compounds with the anode material, preferably with zinc. The solid electrolyte is produced by applying a coating agent, preferably as an aqueous dispersion or suspension, to the steel and/or to the mineral substructure, preferably to concrete. The anode material is characterised in that it forms a galvanic element in combination with the solid electrolyte and the steel to be protected, in which the steel forms the cathode.Type: GrantFiled: August 2, 2005Date of Patent: December 14, 2010Inventor: Wolfgang Schwarz
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Publication number: 20100147703Abstract: A method of protecting steel in concrete is disclosed. A voltage between two connections of a power supply is generated such that current can flow between a negative connection and a positive connection. In a first protection step, one of the connections of the power supply is electrically connected to the steel to be cathodically protected and a sacrificial anode is electrically connected in series with the other connection of the power supply such that the voltage generated by the power supply is added to the voltage generated between the sacrificial anode and the steel to produce a voltage greater than the voltage generated between the sacrificial anode and the steel alone. The power supply may be a cell or battery and may be combined with the sacrificial anode to form a single unit.Type: ApplicationFiled: December 11, 2009Publication date: June 17, 2010Inventors: Gareth Kevin GLASS, Nigel DAVISON, Adrian Charles ROBERTS
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Publication number: 20090065367Abstract: This invention relates to protection of a metal component exposed to a corroding medium. One or more of the following are provided: cathodic protection, measuring of a condition of the component, retarding or avoiding of fouling. A sacrificial anode is used as the energy source such that the electric circuit can provide a pulsating current, voltage, automatically adapted current, or protecting potential. Germanium solid state elements are used.Type: ApplicationFiled: May 1, 2007Publication date: March 12, 2009Inventor: Johannes Jacobus Maria Heselmans
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Patent number: 7422789Abstract: A cathodic protection polymeric compound is disclosed. The compound has flowable material to serve as a binder, carbonaceous conductive media dispersed in the flowable material, sacrificial metal particles also dispersed in the flowable material. The carbonaceous conductive media serve as a carbon-based electron transfer agent and are in the form of particles, platelets, fibers, tubes, or combinations thereof. A galvanic circuit is formed by the metal particles serving as anodes, a metal substrate to be protected serving as the cathode, and the conductive media serving as the electron transfer agent. The flowable material can also include an ionically conductive or an inherently conductive polymer to further enhance the galvanic circuit.Type: GrantFiled: October 22, 2004Date of Patent: September 9, 2008Assignee: Polyone CorporationInventors: Roger W. Avakian, Stephen D. Horton, John H. Hornickel
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Patent number: 7329336Abstract: A cathodic protection system for protecting an underwater structure includes a plurality of blocks which are capable of conforming to various structures. Each of the blocks include: a flexible wire rope, the rope constructed and arranged to pass through the center of each block in two directions, and embedded therein to fasten the blocks to each other by rows and columns; a sacrificial anode embedded in at least one of the blocks, and electrically attached inside the block to the flexible wire rope; and a connecting system electrically attached to the wire rope and to the underwater structure. Each block has a non-abrasive pad attached to it. The pad provides spacing between the block and the underwater structure. The system includes means for collecting performance data from the system. The sacrificial anode is made of a composition taken from the group comprising alloys of: zinc, aluminum, or magnesium.Type: GrantFiled: April 20, 2006Date of Patent: February 12, 2008Assignee: Deepwater Corrosion Services, Inc.Inventor: Jim Britton
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Patent number: 7318889Abstract: An apparatus, system, method and computer program product directed to controlling corrosion of a conductive structure in contact with a corrosive environment and electrically connected to one or more anodes, wherein the anodes are less noble than the conductive structure, where the corrosion is controlled by a controllable filter and a corresponding electronic control unit configured to process at least one stored or measured parameter, and wherein the apparatus, system and method serve to prolong the lifetime of the one or more anodes by reducing, minimizing or substantially eliminating their sacrificial character.Type: GrantFiled: June 2, 2005Date of Patent: January 15, 2008Assignee: Applied Semiconductor International, Ltd.Inventor: David B. Dowling
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Patent number: 7258780Abstract: An apparatus and method for protecting a structure from corrosion, according to which the apparatus includes two pivotally connected members, at least one anode device connected to at least one of the members, and a resilient component engaged with the members.Type: GrantFiled: June 29, 2004Date of Patent: August 21, 2007Assignee: Wellstream International LimitedInventors: Helio Marins David Filho, Robert Ribeiro Braga
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Patent number: 7182852Abstract: The present invention provides a method of testing a cryogenic metal tank before it is put into service, in which said method said tank (1) is filled with water and appropriate measurements are performed where necessary, the method being characterized in that the following steps are performed: filling said metal cryogenic tank (1) with sea water; and providing the bottom and side metal walls (2, 3) of said tank (1) that are constituted essentially by bare steel, with temporary cathodic protection by injecting an electric current into anodes disposed within said tank (1) once said anodes become immersed. Advantageously, a first anode array (51) is placed in the immediate vicinity of the bottom of the tank using support means (52), said support means (52) and said first anode(s) (51) preferably being removable.Type: GrantFiled: October 10, 2003Date of Patent: February 27, 2007Assignee: Saipem S.A.Inventor: Alphonse Boreave
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Patent number: 7147768Abstract: A process of reducing scaling of a metal surface exposed to an aqueous solution from which scale may form after a period of exposure. The process comprises applying a cathodic potential to the surface for at least some of the period of exposure. In some cases, e.g. when an article is made of a ferrous metal, it is advantageous to coat the article with a different metal (e.g. copper or an alloy of copper) before applying the cathodic potential to avoid hydrogen generation and excessive current flow. An article to be protected from scaling may also advantageously be electrically isolated from other parts of an apparatus.Type: GrantFiled: August 15, 2002Date of Patent: December 12, 2006Assignee: Alcan International LimitedInventor: Raymond Breault
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Patent number: 7097746Abstract: An anode protection device and method are provided. The method includes placing a sacrificial anode in proximity to the positive and negative contacts to shield or distort the field therebetween which provides preferential corrosion of the sacrificial anode, instead of the anode. The protection device is a sacrificial anode having various forms and placed in different configurations. In one form the sacrificial anode is a plate. In another form the sacrificial anode is a ring placed around either the positive contact or negative contact to provide a shield between the negative and positive contacts. In a further device embodiment, the sacrificial anodic plate can be welded to the aluminum case of a rechargeable battery of a behind-the-ear (BTE) hearing device.Type: GrantFiled: November 20, 2002Date of Patent: August 29, 2006Assignee: Advanced Bionics CorporationInventors: George Tziviskos, C. Geoffrey E Fernald
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Patent number: 6896779Abstract: A system using tank corrosion sensors to provide for an overall assessment and monitoring of the electro-chemical corrosion and coatings condition in ships' tanks, and particularly in ships' seawater or compensated fuel tanks. The system includes reference half-cells mounted along a suspended cable and one instrumented sacrificial anode at the end of the cable to provide optimal sensing capability within a tank structure. The reference half-cells and the sacrificial anode measure a potential and current output, respectively. Together the measurements provide objective information that can be used to predict corrosion damage and coating deterioration occurring throughout the structure of the tank. The system may be used for an overall assessment and monitoring of the electro-chemical corrosion and coatings condition. In a preferred embodiment, the measurements are stored in a datalogger that is optimally contained within an associated instrument housing.Type: GrantFiled: May 21, 2004Date of Patent: May 24, 2005Assignee: The United States of America as represented by the Secretary of the NavyInventors: Elvin D. Thomas, III, Keith E. Lucas, Paul Slebodnick, Elizabeth A. Hogan
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Patent number: 6890420Abstract: A semiconductor system is provided that uses semiconductive organic polymers, electronics and semiconductor technology to provide a wide array of semiconductor components and a system of preventing corrosion of a surface of a metal structure in contact with a corrosive environment involving: (a) a semiconductive organic polymer coating in conductive contact with at least part of the surface; and (b) an electronic filter for filtering corrosive noise and a method of preventing corrosion using the system.Type: GrantFiled: March 28, 2003Date of Patent: May 10, 2005Assignee: Applied Semiconductor, Inc.Inventor: David B. Dowling
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Publication number: 20040238375Abstract: This invention relates to a method for the protection against corrosion of steel parts made of austenitic or semi-austenitic steel during the production of sulfuric acid. To improve the corrosion resistance of the steel parts which are in contact with the sulfuric acid, it is proposed to use austenitic or semi-austenitic steel which has a Cr content of 15 wt-% to 36 wt-% and an Ni content of 9 wt-% to 60 wt-% and in which the ratio of the chemical elements (Cr+Si)/(Ni+Mo) lies in the range from 0.9 to 1.9 or in which the ratio of the chemical elements Cr/(Ni+Mo) lies in the range from 0.8 to 1.5, and to additionally provide this steel part with an anodic corrosion protection.Type: ApplicationFiled: July 9, 2004Publication date: December 2, 2004Inventors: Karl-Heinz Daum, Wolf-Christoph Rauser, Nikola Anastasijevic, Wolfram Schalk, Stephan Laibach, Herbert Schnaubelt
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Patent number: 6811681Abstract: An apparatus, system, method and computer program product directed to controlling corrosion of a conductive structure in contact with a corrosive environment and coated with a semiconductive coating, where the corrosion is controlled by a controllable filter and a corresponding electronic control unit configured to process at least one stored or measured parameter.Type: GrantFiled: November 12, 2002Date of Patent: November 2, 2004Assignee: Applied Semiconductor International Ltd.Inventors: David B. Dowling, Farshad Khorrami
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Patent number: 6793800Abstract: Cathodic protection of an existing concrete structure, including a steel member at least partly buried, such as steel rebar, in the concrete structure, is provided by embedding anodes into a fresh concrete layer applied over an excavated patch and/or as a covering overlay. The anodes are embedded at spaced positions or as an array in the layer and connected to the rebar. A corrosion inhibitor is added into the fresh concrete at least at the interface and more preferably in admixture with the fresh concrete which acts to reduce the flow of ionic current to the steel or between the anode member and the steel in the fresh covering material without significantly increasing the resistivity of the fresh covering material and without inhibiting the ionic current between the anode member and the fresh covering material. In this way the current to the steel in the existing concrete is maximized to maximize the cathodic protection to the existing steel which is the primary target.Type: GrantFiled: December 20, 2002Date of Patent: September 21, 2004Inventor: David Whitmore
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Publication number: 20040134795Abstract: This invention pertains to the protection of metals from corrosion and/or fouling from exposure to environments such as, for example, seawater. The protection in accordance with this invention is achieved through the use of conductive zinc-containing coatings in combination with applied current cathodic protection.Type: ApplicationFiled: July 23, 2003Publication date: July 15, 2004Inventors: Daniel R. Demarco, Basil V. Gregorovich, Robert C. Nahas, Shi Hua Zhang
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Patent number: 6692633Abstract: Resistance to corrosion of aluminum metallization on semiconductor devices during wafer sawing process is provided by a sacrificial anode containing magnesium in contact with the integrated circuit wafer and the dicing saw. A relatively thin film or disc of magnesium directly in contact with the surface of the dicing blade makes use of cooling water to serve as the electrolyte between the magnesium and aluminum surfaces, and in turn corrosion is transferred to the magnesium anode in preference to the aluminum of the semiconductor device.Type: GrantFiled: December 21, 2001Date of Patent: February 17, 2004Assignee: Texas Instruments IncorporatedInventor: John P. Tellkamp
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Patent number: 6551491Abstract: A system for preventing corrosion of a surface of a metal structure in contact with a corrosive environment comprising: (a) a semiconductive coating in conductive contact with at least part of the surface; and (b) an electronic filter for filtering corrosive noise and a method of preventing corrosion using the system.Type: GrantFiled: November 9, 2001Date of Patent: April 22, 2003Assignee: Applied Semiconductor, Inc.Inventors: David Dowling, Art Spivack
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Patent number: 6524466Abstract: A system for preventing corrosion and/or fouling of a surface of a biomedical device in contact with a corrosive environment comprising: (a) a semiconductive coating in conductive contact with at least part of the surface; and (b) an electronic filter for filtering corrosive noise and a method of preventing corrosion and/or fouling using the system.Type: GrantFiled: July 18, 2000Date of Patent: February 25, 2003Assignee: Applied Semiconductor, Inc.Inventors: Joseph Bonaventura, Louis Ignarro, David B. Dowling, Arthur J. Spivack
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Publication number: 20020195353Abstract: A semiconductor system is provided that uses semiconductive organic polymers, electronics and semiconductor technology to provide a wide array of semiconductor components and a system of preventing corrosion of a surface of a metal structure in contact with a corrosive environment involving:Type: ApplicationFiled: June 25, 2001Publication date: December 26, 2002Applicant: APPLIED SEMICONDUCTOR, INC.Inventor: David B. Dowling
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Patent number: 6471851Abstract: Humectants are applied to cathodic protection systems which utilize thermally-sprayed zinc or zinc alloy anodes applied to the surface of reinforced concrete structures. The humectants are deliquescent or hygroscopic organic or inorganic salts, hydrophilic polymers or colloids, or organic liquid desiccants. The humectants are positioned at or near the interface between the anodes and the concrete and increase the moisture content at the interface. This increases the ability of the anode to deliver cathodic protection current to steel embedded in the concrete. The humectants may be applied to the concrete surface prior to application of the anode, or may be applied subsequent to installation of the anode.Type: GrantFiled: April 17, 1997Date of Patent: October 29, 2002Inventor: Jack E. Bennett
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Patent number: 6425997Abstract: A process for removing chloride ions from steel surfaces and measuring the amount present on the steel surface being tested employs a high frequency waveform alternating current treatment as a pre-measurement step to liberate the chloride ions into deionized water on the steel surface being tested. The conductivity of the water containing the chloride ions is measured in a conductivity cell mounted on the same steel surface being tested. Recovery of chloride ions originally present on the steel test surface (cathode) is 85-95% complete when a sine wave high frequency alternating current is used between the steel test surface (cathode) sealed below an insulating plastic box containing the deionized water and which plastic box contains a steel plate (anode) mounted within and immediately below the inside top of the plastic box conductivity cell. The conductivity of the water in the cell is measured by a conductivity meter after disconnecting the high frequency waveform alternating current.Type: GrantFiled: June 20, 2000Date of Patent: July 30, 2002Inventor: William C. Johnson
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Publication number: 20020092778Abstract: This invention relates to a process for the derusting or removal of corrosion products form ferrous metal substrates by electrochemical treatment.Type: ApplicationFiled: November 29, 2000Publication date: July 18, 2002Applicant: COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCHInventors: Nerur Sankaranayan Rengaswamy, Sironmani Palraj, Gopalan Subramanian, Thirupathisaram Muthukrishna Balasubramanian
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Patent number: 6402933Abstract: A system for preventing corrosion of a surface of a metal structure in contact with a corrosive environment comprising: (a) a semiconductive organic polymer coating in conductive contact with at least part of the surface; and (b) an electronic filter for filtering corrosive noise and a method of preventing corrosion using the system.Type: GrantFiled: June 8, 2001Date of Patent: June 11, 2002Assignee: Applied Semiconductor, Inc.Inventor: David B. Dowling
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Publication number: 20020046956Abstract: A system for preventing corrosion of a surface of a metal structure in contact with a corrosive environment comprising:Type: ApplicationFiled: November 9, 2001Publication date: April 25, 2002Applicant: APPLIED SEMICONDUCTOR, INC.Inventors: David Dowling, Art Spivack
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Patent number: 6331242Abstract: Corrosible metallic elements of tank are protected by an anodic encasement sleeve. The anodic encasement sleeve employs an inner sacrificial anodic layer and an outer environmental barrier layer to provide both cathodic and barrier protection against corrosion. Following application of the sleeve, typically by drawing or wrapping, the anodic encasement sleeve remains substantially unbonded from the tank, though it is electrically connected by conductive means. Because of the substantially unbonded relationship between the sacrificial anodic layer and the metallic elements of the tank, if electrolyte is present under the environmental barrier (due to breaches, installation error, condensation, etc.), the electrolyte may enter the unbonded area between the tank and the anodic material. This increases the ratio of anodic material to tank available, which makes the cathodic protection more efficient and effective for an extended duration.Type: GrantFiled: June 21, 2000Date of Patent: December 18, 2001Assignee: United States Pipe and Foundry Company, Inc.Inventor: A. Michael Horton
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Patent number: 6325915Abstract: A system for preventing corrosion of a surface of a metal structure in contact with a corrosive environment comprising: (a) a semiconductive coating in conductive contact with at least part of the surface; and (b) an electronic filter for filtering corrosive noise and a method of preventing corrosion using the system.Type: GrantFiled: June 2, 2000Date of Patent: December 4, 2001Assignee: Applied Semiconductor, Inc.Inventors: David Dowling, Art Spivack
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Patent number: 6303017Abstract: Reinforcement in concrete is cathodically protected by galvanically connecting a sacrificial anode, such as a zinc or zinc alloy anode, to the reinforcement, and contacting the anode with an electrolyte solution having a pH which is maintained sufficiently high for corrosion of the anode to occur, and for passive film formation on the anode to be avoided. The pH of the electrolyte is preferably at least 0.2 units, and preferably from 0.5 units to more than 1.0 units, above the pH value at which passivity of the anode would occur. The electrolyte may be for example sodium hydroxide or potassium hydroxide but is preferably lithium hydroxide which also acts as an alkali-silica reaction inhibitor.Type: GrantFiled: August 20, 1999Date of Patent: October 16, 2001Assignee: Aston Material Services LimitedInventors: Christopher L. Page, George Sergi
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Patent number: 6224743Abstract: Apparatus, compositions and methods provide cathodic protection to a structure by placing an anode layer (10) directly between the structure (22) and its underlying foundation (30). Structures contemplated to be protected in this manner include especially very large structures such as above ground storage tanks. In one aspect of preferred embodiments, the anode layer (10) comprises sheets of at least 85% aluminum with other alloying elements such as magnesium (0.05 to 6%), zinc (0.1 to 8%), indium (0.005 to 0.03%) and tin (0.05 to 0.2%) added for the purposes of optimizing current yield, polarization and ease of manufacturing the sheet.Type: GrantFiled: June 16, 2000Date of Patent: May 1, 2001Assignee: Fluor Daniel, Inc.Inventor: Reddi Satyanarayana
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Patent number: 6033553Abstract: The present invention relates to the field of cathodic protection of reinforced concrete. A conductive metal is thermally applied onto an exposed surface of the concrete in an amount effective to form an anode on the surface. This establishes an interface between the anode and the concrete. The thermal application is performed in a manner which is effective to impart permeability to the anode. A lithium salt solution selected from the group consisting of lithium nitrate solution, lithium bromide solution, and combinations thereof is applied to the external surface of the anode. The solution migrates by capillary attraction to the interface of the anode with the concrete depositing the lithium salt at the interface. The lithium salt functions as a current enhancing agent. The salt also functions as a humectant absorbing moisture from the atmosphere thereby providing an electrolyte at the interface. These combined effects substantially increase current delivery from the anode.Type: GrantFiled: January 25, 1999Date of Patent: March 7, 2000Inventor: Jack E. Bennett
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Patent number: 5714045Abstract: A jacketed anode assembly for use in a sacrificial anode cathodic protection system deployed to impede corrosion of steel or steel reinforcement in pilings or similar supporting columns. A non-conductive jacket formed of mating shell halves is lined along its interior surface with sheets of expanded metal such as expanded zinc. The metal sheets are of a composition higher on the galvanic series than the steel reinforcement such that the sheets serve as sacrificial anodes when coupled with the steel reinforcement. The jacket and zinc lining are installed as a unit on the piling with the jacket interior surface facing the periphery of the piling and in spaced apart relationship therewith. In this space, a filling material can be introduced to both secure the metal sheets in place between the jacket and piling as well as serve as an electrolyte between the steel reinforcement and the metal sheet.Type: GrantFiled: November 8, 1996Date of Patent: February 3, 1998Assignees: Alltrista Corporation, Florida Department of TransportationInventors: Ivan R. Lasa, Rodney G. Powers, Douglas L. Leng
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Patent number: 5667649Abstract: Impressed current anodes such as cathodic protection anodes comprise iron based alloys including less than 70% iron and less than 0.1% carbon. Additional components may include molybdenum, chromium, nickel and others. The iron based alloy may itself comprises the anode or it may provide a substrate to which an electrolytic coating is applied.Type: GrantFiled: June 29, 1995Date of Patent: September 16, 1997Inventor: James B. Bushman
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Patent number: 5650060Abstract: An ionically conductive agent having means for reducing passivation of metal subject to anodic dissolution is disclosed. The ionically conductive agent is interposed between metal to be protected from corrosion and metal to be sacrificed to provide cathodic protection. An electrical connection between the two metals completes a galvanic circuit. The means for reducing passivation can be either a complexing agent for ions of the metal to be sacrificed or can be a membrane to inhibit flow of ions that would affect the ability of the ionically conductive medium to support continued anodic metal dissolution. The ionically conductive agent and a system for cathodic protection using the ionically conductive agent is particularly suitable for a galvanic circuit to cathodically protect reinforcement bars in concrete structures such as transportation bridges, transportation highways, parking facilities, and balconies exposed to corrosive environments.Type: GrantFiled: January 28, 1994Date of Patent: July 22, 1997Assignee: Minnesota Mining and Manufacturing CompanyInventors: Haitao Huang, Richard B. Hartman, Timothy M. Dietz
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Patent number: 5643424Abstract: A device and method for preventing fouling and/or corrosion of the exposed surfaces of a structure which is in contact with seawater, brackish water, fresh water, or a combination of these. The system includes using a structure having an exposed zinc-containing surface. At the exposed surface water interface a negative capacitive charge or an asymmetric alternating electrostatic is induced and maintained.Type: GrantFiled: June 29, 1994Date of Patent: July 1, 1997Assignee: Marine Environmental Research, Inc.Inventors: William J. Riffe, Jack D. Carter
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Patent number: 5630934Abstract: Treatment is described for acidity caused by water seeping down through a seam of acid-generating mineral such as pyrite. The pyrite oxidises through exposure to the atmosphere (as a result of mine workings). The treatment system creates an galvanic cell, using the submerged portion of the pyrite seam as the cathode, the water in the aquifer as the electrolyte, and a body of scrap iron immersed in the water as the (sacrificial) anode. Contact rods are inserted into the pyrite seam, and are connected, via a cable, to the body of scrap iron, which is placed in a nearby pond. Hydrogen ions migrate to the cathode and bubble off as hydrogen gas, raising the pH. The acid generating reactions in the pyrite seam are inhibited, and acid concentrations in the already contaminated water in the pond and in the aquifer are reduced. In an alternative, the exposed beaches of pyrite in a tailings pond are provided with grids of metal mesh or graphite in place of the inserted rods.Type: GrantFiled: August 23, 1995Date of Patent: May 20, 1997Assignee: Enpar Technologies Inc.Inventors: Ward Chesworth, Gene S. Shelp, Barry J. Shelp
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Patent number: 5505826Abstract: A method and apparatus for reducing corrosion on the interior and exterior of a fuel storage tank. A galvanic anode assembly is placed within the interior of or exterior to the fuel storage tank and is surrounded by a layer of hydrophilic gel. The hydrophilic gel absorbs water in the fuel storage tank, thus removing it from contact with the tank. The hydrophilic gel also absorbs metal ions produced as the anode is consumed. The hydrophilic gel is maintained around the anode assembly by a porous container. The anode, hydrophilic gel, and porous container are maintained within a flexible container that allows water and fluid contained within the fuel storage tank to contact the hydrophilic gel. In one embodiment, the hydrophilic gel includes a polyacrylamide material.Type: GrantFiled: November 30, 1994Date of Patent: April 9, 1996Inventors: Patrick G. Haglin, Stuart J. Ell