Patents by Inventor Thomas P. Diaz

Thomas P. Diaz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9533270
    Abstract: A system and method of injecting a chemical into a high pressure process stream without pumps or other active components. The system utilizes the differential pressure created by resistive losses of downstream components within a high pressure process stream. A bypass side stream is taken from an upstream pressure location and returned to the downstream side of the resistive inline process component. The chemical solution vessel is pressurized by the higher side of the pressure differential. The solution then passes through a flow controlling capillary tube exiting on the lower pressure differential side into the bypass stream. The high flow rate chemically diluted bypass stream then returns to the process stream at the lower differential process stream tie-in. The chemical solution is isolated from the process water pressuring the vessel by a movable separating device preventing mixing of the two fluids. The vessel can also be pressurized by gas.
    Type: Grant
    Filed: June 6, 2014
    Date of Patent: January 3, 2017
    Inventors: Robert James Law, Robert L Cowan, Thomas P Diaz, Samson Hettiarachchi
  • Publication number: 20140360606
    Abstract: A system and method of injecting a chemical into a high pressure process stream without pumps or other active components. The system utilizes the differential pressure created by resistive losses of downstream components within a high pressure process stream. A bypass side stream is taken from an upstream pressure location and returned to the downstream side of the resistive inline process component. The chemical solution vessel is pressurized by the higher side of the pressure differential. The solution then passes through a flow controlling capillary tube exiting on the lower pressure differential side into the bypass stream. The high flow rate chemically diluted bypass stream then returns to the process stream at the lower differential process stream tie-in. The chemical solution is isolated from the process water pressuring the vessel by a movable separating device preventing mixing of the two fluids. The vessel can also be pressurized by gas.
    Type: Application
    Filed: June 6, 2014
    Publication date: December 11, 2014
    Inventors: Robert James Law, Robert L. Cowan, Thomas P. Diaz, Samson Hettiarachchi
  • Patent number: 8054933
    Abstract: An injection system designed to deliver a chemical solution into a reactor through feedwater system taps during normal operating condition of a power reactor is disclosed. The process of delivery is via positive displacement pumps. Injection of chemical is in a concentrated solution form, which is internally diluted by the system prior to discharging from the skid. The injection system minimizes chemical loss due to deposition on the transit line, enables a higher concentrated solution to be used as the injectant, eliminates the time consuming laborious process of chemical dilution, raises chemical solution to the pressure required for injection, prevents solid precipitations out of solution at the injection pump head through the use of a flush solution, and deposits fresh chemical on new crack surfaces that develop during a power reactor start-up, shutdown and operation.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: November 8, 2011
    Assignee: GE-Hitachi Nuclear Energy Americas LLC
    Inventors: Luong Cam Tran, Thomas P. Diaz, Samson Hettiarachchi, Paul Y. Shu, David P. Siegwarth
  • Publication number: 20090154636
    Abstract: An injection system designed to deliver a chemical solution into a reactor through feedwater system taps during normal operating condition of a power reactor is disclosed. The process of delivery is via positive displacement pumps. Injection of chemical is in a concentrated solution form, which is internally diluted by the system prior to discharging from the skid. The injection system minimizes chemical loss due to deposition on the transit line, enables a higher concentrated solution to be used as the injectant, eliminates the time consuming laborious process of chemical dilution, raises chemical solution to the pressure required for injection, prevents solid precipitations out of solution at the injection pump head through the use of a flush solution, and deposits fresh chemical on new crack surfaces that develop during a power reactor start-up, shutdown and operation.
    Type: Application
    Filed: December 17, 2007
    Publication date: June 18, 2009
    Applicant: GE-Hitachi Nuclear Energy Americas LLC
    Inventors: Luong Cam Tran, Thomas P. Diaz, Samson Hettiarachchi, Paul Y. Shu, David P. Siegwarth
  • Patent number: 6714618
    Abstract: Method for controlling the amount of metal atoms deposited into an oxide layer present on a metal surface, which metal atoms increase the corrosion resistance of metal when present in the oxide film, wherein the metal surface is submerged in water at a selected temperature within the range of about to 200° to 550° F.; and a solution of a compound containing the metal which increases the corrosion resistance of the metal surface when present in the oxide film is injected into the water. The compound decomposes at the selected temperature to release atoms of the metal which incorporate in the oxide film at a desired loading.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: March 30, 2004
    Assignee: General Electric Company
    Inventors: Samson Hettiarachchi, Robert J. Law, David P. Siegwarth, Thomas P. Diaz, Robert L. Cowan
  • Patent number: 6697449
    Abstract: Method for controlling the amount of metal atoms deposited into an oxide layer present on a metal surface, which metal atoms increase the corrosion resistance of metal when present in the oxide film, wherein the metal surface is submerged in water at a selected temperature within the range of about to 200° to 550° F.; and a solution of a compound containing the metal which increases the corrosion resistance of the metal surface when present in the oxide film is injected into the water. The compound decomposes at the selected temperature to release atoms of the metal which incorporate in the oxide film at a desired loading.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: February 24, 2004
    Assignee: General Electric Company
    Inventors: Samson Hettiarachchi, Robert J. Law, David P. Siegwarth, Thomas P. Diaz, Robert L. Cowan
  • Publication number: 20020181644
    Abstract: Method for controlling the amount of metal atoms deposited into an oxide layer present on a metal surface, which metal atoms increase the corrosion resistance of metal when present in the oxide film, wherein the metal surface is submerged in water at a selected temperature within the range of about to 200° to 550° F.; and a solution of a compound containing the metal which increases the corrosion resistance of the metal surface when present in the oxide film is injected into the water.
    Type: Application
    Filed: April 10, 2002
    Publication date: December 5, 2002
    Applicant: General Electric Company
    Inventors: Samson Hettiarachchi, Robert J. Law, David P. Siegwarth, Thomas P. Diaz, Robert L. Cowan
  • Publication number: 20020101953
    Abstract: Method for reducing corrosion of alloy components in a water cooled nuclear reactor or associated components comprising the step of injecting into the water of the reactor in the presence of zinc a noble metal cation-releasing compound which releases noble metal cations or cationic species containing noble metal species into the reactor water under operating reactor thermal conditions.
    Type: Application
    Filed: April 1, 2002
    Publication date: August 1, 2002
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Samson Hettiarachchi, David P. Siegwarth, Robert L. Cowan, Robert J. Law, Thomas P. Diaz
  • Patent number: 5774516
    Abstract: A method for mitigating general corrosion and crack initiation and growth on the surface of a metal components in a water-cooled nuclear reactor. A compound containing a non-noble metal such as zirconium or titanium is injected into the water of the reactor in the form of a solution or suspension. This compound decomposes under reactor thermal conditions to release ions or atoms of the non-noble metal which incorporate in the surfaces of the components, including the interior surfaces of any cracks formed therein. The preferred compounds are zirconium compounds such as zirconium acetylacetonate, zirconium nitrate and zirconyl nitrate. Zirconium incorporated in the oxided surface of a metal component will reduce the electrochemical corrosion potential at the surface to a level below the critical potential to protect against intergranular stress corrosion cracking without the addition of hydrogen.
    Type: Grant
    Filed: August 15, 1996
    Date of Patent: June 30, 1998
    Assignee: General Electric Company
    Inventors: Samson Hettiarachchi, Young J. Kim, Peter L. Andresen, Thomas P. Diaz
  • Patent number: 5625656
    Abstract: A method for ensuring the distribution of noble metal in the reactor circuit during plant application without measuring the reactor water for noble metal content by chemical analysis. The method involves the measurement of electrochemical corrosion potential in an autoclave or a high-flow test section that is connected to the reactor water circuit through sample lines downstream of the injection port, preferably the point in the reactor circuit which is furthest from the injection port. If the noble metal flows into the autoclave or test section at these distant points in the reactor circuit, then the noble metal will deposit on the test specimens inside the autoclave or test section.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: April 29, 1997
    Assignee: General Electric Company
    Inventors: Samson Hettiarachchi, Robert L. Cowan, II, Robert J. Law, Thomas P. Diaz
  • Patent number: 5608766
    Abstract: A method for improving the performance and longevity of coatings of metal deposited from aqueous solutions of inorganic, organic or oraganometallic metal compounds. The method involves co-deposition of noble metal or corrosion-inhibiting non-noble metal during growth of oxide film on a component made of alloy, e.g., stainless steels and nickel-based alloys. The result is a metal-doped oxide film having a relatively longer life in the reactor operating environment. In particular, incorporation of palladium into the film provides greatly increased catalytic life as compared to palladium coatings which lie on the oxide surface.
    Type: Grant
    Filed: October 13, 1994
    Date of Patent: March 4, 1997
    Assignee: General Electric Company
    Inventors: Peter L. Andresen, Samson Hettiarachchi, Young J. Kim, Thomas P. Diaz
  • Patent number: 5602888
    Abstract: A method for mitigating crack growth on the surface of stainless steel or other alloy components in a water-cooled nuclear reactor wherein a solution or suspension of a compound containing a noble metal is injected into the coolant water while the reactor is not generating nuclear heat, e.g., during shutdown or recirculation pump heatup. During shutdown, the reactor coolant water reaches temperatures as low as 120.degree. F., in contrast to the water temperature of 550.degree. F. during normal operation. During pump heatup, the water temperature reaches 400.degree.-450.degree. F. At these reduced temperatures, the rate of thermal decomposition of the injected noble metal compound is reduced. However, radiation-induced decomposition also occurs inside the reactor. In particular, the noble metal compound can be decomposed by the gamma radiation emanating from the nuclear fuel core of the reactor.
    Type: Grant
    Filed: April 5, 1995
    Date of Patent: February 11, 1997
    Assignee: General Electric Company
    Inventors: Samson Hettiarachchi, Thomas P. Diaz, Gary P. Wozadlo
  • Patent number: 5600691
    Abstract: A method for mitigating crack growth on the surface of stainless steel or other metal components in a water-cooled nuclear reactor. A compound containing a noble metal, e.g., palladium, is injected into the water of the reactor in the form of a solution or suspension. This compound has the property that it decomposes under reactor thermal conditions to release ions/atoms of the noble metal which incorporate in or deposit on the interior surfaces of the crack. The compound may be organic, organometallic (e.g., palladium acetylacetonate) or inorganic in nature. The palladium deposited inside a crack should exhibit catalytic behavior even if the bulk surface palladium is depleted under high fluid flow conditions. As a result, the electrochemical potential inside the crack is decreased to a level below the critical potential to protect against intergranular stress corrosion cracking.
    Type: Grant
    Filed: March 10, 1994
    Date of Patent: February 4, 1997
    Assignee: General Electric Company
    Inventors: Samson Hettiarachchi, Robert L. Cowan, II, Thomas P. Diaz, Gary P. Wozadlo
  • Patent number: 5386442
    Abstract: An apparatus and a method for measuring and controlling the crack growth rate within a double cantilever beam type test specimen. The arms of the test specimen are fitted with a pressure-actuated bellows to induce a predetermined load and with a sensing assembly to provide feedback on the amount of beam displacement resulting from application of that load. In this manner a loaded test specimen may be remotely mounted and adjusted inside the reactor pressure vessel or piping of a nuclear reactor in order to maintain a stress intensity which is constant or which varies in a predetermined manner for inducing stress corrosion cracking or corrosion fatigue in the specimen.
    Type: Grant
    Filed: June 25, 1993
    Date of Patent: January 31, 1995
    Assignee: General Electric Company
    Inventors: Thomas P. Diaz, Peter L. Andresen, William R. Catlin, Gary W. Contreras, Ronald E. De Lair, William D. Miller, Harvey D. Solomon, Daniel Weinstein
  • Patent number: 5369675
    Abstract: Electrically controlled load activating mechanisms that can be used inside the containment vessel of a nuclear reactor in conjunction with bellows-loaded DCB crack growth sensors installed inside the reactor pressure vessel or piping of a nuclear reactor. One mechanism is a liquid-filled, double-bellows master/slave arrangement connected by a capillary tube to transmit the loading provided by a linear motion device. Another mechanism uses a heat-resistant gas bottle that can be heated in a furnace to increase the gas pressure to expand the bellows of the DCB sensor. A third mechanism uses a pump or compressor to provide the necessary expansion force. The loading is controlled via electrical connections that do not require special pressure boundary penetrations of the containment vessel.
    Type: Grant
    Filed: June 25, 1993
    Date of Patent: November 29, 1994
    Assignee: General Electric Company
    Inventors: Thomas P. Diaz, Gary W. Contreras, Gerald M. Gordon, Veronica L. McCarthy, Daniel Weinstein
  • Patent number: 5349869
    Abstract: A double-cantilever beam crack growth sensor made from welded alloy, e.g., nickel-based alloy, and a method for fabricating such sensors. The method includes the steps of forming a strongback from a block of a first nickel-based alloy; depositing a suitable thickness of nickel-based weld alloy on top of the strongback to form a bi-metallic test block; welding a second block of the first nickel-based alloy on top of the weld alloy; and machining the final three-layer block to form a double-cantilever beam crack growth sensor consisting of cantilever beams made of the first nickel-based alloy, a crack growth section of weld alloy having a microstructure wherein the direction of dendritic growth is parallel to the direction of crack growth and a third section made of the first nickel-based alloy.
    Type: Grant
    Filed: April 5, 1993
    Date of Patent: September 27, 1994
    Assignee: General Electric Company
    Inventors: Thomas P. Diaz, Gail E. Dunning, Ronald E. LeBlanc
  • Patent number: 5013370
    Abstract: A metallic object is treated to produce tensile residual stress in a known localized area of the metallic object. A metallic object having at least one portion substantially free of tensile residual stress is provided, and a localized area adjacent to or a part of the tensile stress-free area is selected. The localized area is subjected to heating on one surface and cooling on the opposite surface. Upon cooling to ambient temperature, the known localized area has tensile residual stress. The localized area can have cracks formed therein by crack-promotion techniques, such as submersion in boiling magnesium chloride. The area can be tested by attaching electrodes and subjecting the area to a reversing direct current crack growth measurement procedure.
    Type: Grant
    Filed: July 2, 1990
    Date of Patent: May 7, 1991
    Assignee: General Electric Company
    Inventor: Thomas P. Diaz