Catalytic Patents (Class 376/301)
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Patent number: 11043309Abstract: The present invention relates generally to the field of compensation methods for nuclear reactors and, in particular to a method for fail-safe reactivity compensation in solution-type nuclear reactors. In one embodiment, the fail-safe reactivity compensation method of the present invention augments other control methods for a nuclear reactor. In still another embodiment, the fail-safe reactivity compensation method of the present invention permits one to control a nuclear reaction in a nuclear reactor through a method that does not rely on moving components into or out of a reactor core, nor does the method of the present invention rely on the constant repositioning of control rods within a nuclear reactor in order to maintain a critical state.Type: GrantFiled: August 17, 2017Date of Patent: June 22, 2021Assignee: BWXT Technical Services Group, Inc.Inventors: Erik T. Nygaard, Peter L. Angelo, Scott B. Aase
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Patent number: 10450660Abstract: Electrochemical cells and methods are described that can be utilized for the recovery of tritium directly from a molten lithium metal solution without the need for a separation or concentration step prior to the electrolytic recovery process. The methods and systems utilize an ion conducting electrolyte that conducts either lithium ion or tritide ion across the electrochemical cell.Type: GrantFiled: November 3, 2015Date of Patent: October 22, 2019Assignee: Savannah River Nuclear Solutions, LLCInventors: Brenda L. Garcia-Diaz, David W. Babineau, Hector R. Colon-Mercado, Joseph A. Teprovich, Luke C. Olson, Roderick E. Fuentes
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Patent number: 10322788Abstract: Disclosed is a ballast water treatment system including: a ballast water supply unit for supplying seawater employed as ballast water to a ballast water tank; an electrolysis device receiving a part of the seawater being supplied to the ballast water tank, and generating sodium hypochlorite and hydrogen gas as by-product gas by electrolyzing the part of the seawater being supplied to the ballast water tank via the ballast water supply unit; and a hydrogen gas removing device receiving a gas-liquid mixture of electrolyzed water and the hydrogen gas that are generated in the electrolysis device, removing the hydrogen gas by a catalyst reaction, and supplying remaining electrolyzed water to the ballast water tank via the ballast water supply unit.Type: GrantFiled: November 23, 2016Date of Patent: June 18, 2019Assignee: Techwin Co, Ltd.Inventors: Boong Ik Jung, Jung Sik Kim, Hyun Su Shin, Sun Duk Hwang
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Patent number: 10252922Abstract: Disclosed is an electrolysis device including: an electrolyzing tank generating electrolyzed water and hydrogen gas as by-product gas by electrolyzing raw water supplied from a raw water supply unit; and a catalyst reaction tank having therein a hydrophobic catalyst, and receiving the hydrogen gas generated from the electrolyzing tank, and removing the hydrogen gas by a catalyst reaction.Type: GrantFiled: November 23, 2016Date of Patent: April 9, 2019Assignee: Techwin Co., Ltd.Inventors: Boong Ik Jung, Jung Sik Kim, Hyun Su Shin, Sun Duk Hwang
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Patent number: 9689856Abstract: Compositions and methods are provided for assessing the presence or absence, and optionally quantitating, the surface loading of a noble metal such as platinum on the surface of a substrate. The invention utilizes the decomposition rate of hydrogen peroxide (H2O2) or other redox active molecule following exposure to the substrate surface to effectively establish a qualitative or quantitative correlation between the redox agent survival fraction and the presence or absence of noble metal (e.g., platinum), and further, for the quantitation of noble metal loading on the substrate surface. The invention finds applicability in assessing the surface loading of noble metals on the internal surfaces of boiling water nuclear reactor plants (BWR) that have undergone prior noble metal application.Type: GrantFiled: April 8, 2016Date of Patent: June 27, 2017Assignee: ELECTRIC POWER RESEARCH INSTITUTEInventors: Susan Elaine Garcia, Thomas Pompilio Diaz, Samson Hettiarachchi, Rajeshwar Singh Pathania
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Patent number: 9496058Abstract: Systems passively eliminate noncondensable gasses from facilities susceptible to damage from combustion of built-up noncondensable gasses, such as H2 and O2 in nuclear power plants, without the need for external power and/or moving parts. Systems include catalyst plates installed in a lower header of the Passive Containment Cooling System (PCCS) condenser, a catalyst packing member, and/or a catalyst coating on an interior surface of a condensation tube of the PCCS condenser or an annular outlet of the PCCS condenser. Structures may have surfaces or hydrophobic elements that inhibit water formation and promote contact with the noncondensable gas. Noncondensable gasses in a nuclear power plant are eliminated by installing and using the systems individually or in combination. An operating pressure of the PCCS condenser may be increased to facilitate recombination of noncondensable gasses therein.Type: GrantFiled: November 17, 2014Date of Patent: November 15, 2016Assignee: GE-HITACHI NUCLEAR ENERGY AMERICAS LLCInventors: Wayne Marquino, Stephan C. Moen, Richard M. Wachowiak, John L. Gels, Jesus Diaz-Quiroz, John C. Burns, Jr.
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Patent number: 9410252Abstract: A method for injecting a corrosion inhibitor injecting an oxidant and an anticorrosive agent-pH adjusting agent complex including an anticorrosive agent and a pH adjusting agent adsorbed on a surface of the anticorrosive agent into high temperature water in contact with a surface of a metal structural material and irradiating the high temperature water with a radioactive ray or an ultraviolet ray, wherein the anticorrosive agent of the anticorrosive agent-pH adjusting agent complex has, on the surface of the anticorrosive agent, an active site where the pH adjusting agent reacts with the oxidant, and the pH adjusting agent present on the surface of the anticorrosive agent of the anticorrosive agent-pH adjusting agent complex and/or in the high temperature water is oxidized with the oxidant by the irradiation with the radioactive ray or the ultraviolet ray to change pH adjusting ability of the pH adjusting agent and shift a pH of the high temperature water to a neutral side, and thereby deposition of the anticType: GrantFiled: September 13, 2012Date of Patent: August 9, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Masato Okamura, Tetsuo Oosato, Kazuo Murakami, Seiji Yamamoto, Hiroyuki Arai, Hidehiro Urata, Hajime Hirasawa, Osamu Shibasaki, Koji Negishi
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Patent number: 8917810Abstract: Systems passively eliminate noncondensable gasses from facilities susceptible to damage from combustion of built-up noncondensable gasses, such as H2 and O2 in nuclear power plants, without the need for external power and/or moving parts. Systems include catalyst plates installed in a lower header of the Passive Containment Cooling System (PCCS) condenser, a catalyst packing member, and/or a catalyst coating on an interior surface of a condensation tube of the PCCS condenser or an annular outlet of the PCCS condenser. Structures may have surfaces or hydrophobic elements that inhibit water formation and promote contact with the noncondensable gas. Noncondensable gasses in a nuclear power plant are eliminated by installing and using the systems individually or in combination. An operating pressure of the PCCS condenser may be increased to facilitate recombination of noncondensable gasses therein.Type: GrantFiled: September 10, 2010Date of Patent: December 23, 2014Assignee: GE-Hitachi Nuclear Energy Americas LLCInventors: Wayne Marquino, Stephan C. Moen, Richard M. Wachowiak, John L. Gels, Jesus Diaz-Quiroz, John C. Burns, Jr.
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Patent number: 8848856Abstract: A method and a system for catalytic recombination of hydrogen, which is carried in a gas flow, with oxygen, has the gas flow passed through a reaction zone with a number of catalytic converter elements, with steam being added to the gas flow before it enters the reaction zone. The method and system ensure a particularly high operational reliability of the recombination device, even in varying operating conditions or with varying operating methods, in particular with regard to a hydrogen feed, which is provided as required, in the steam/feed water circuit of the installation. For this purpose, the feed rate of the steam to be added is adjusted in dependence on a measured value which is characteristic of a current actual temperature in the reaction zone.Type: GrantFiled: March 9, 2009Date of Patent: September 30, 2014Assignee: Areva GmbHInventors: Bernd Eckardt, Robert Feuerbach
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Publication number: 20140064427Abstract: At the time of loss of coolant accident, when station blackout occurs, hydrogen, radioactive nuclides, and steam are discharged from a broken portion of a pipe connected to a reactor pressure vessel into the primary containment vessel. A passive autocatalytic hydrogen treatment apparatus installs a catalytic layer and heat exchanger tubes of a heat exchanger in a casing. High-temperature steam including hydrogen and radioactive nuclides is supplied into the heat exchanger tubes and heats gas supplied into the casing 3. The steam is condensed in the heat exchanger tubes and generates mists. The mists are removed by a mist separator together with the radioactive nuclides. The gas including hydrogen fed from the mist separator in the casing is heated by the aforementioned steam and is introduced into the catalytic layer. Hydrogen is combined with oxygen in the catalytic layer to steam.Type: ApplicationFiled: August 29, 2013Publication date: March 6, 2014Applicant: HITACHI-GE NUCLEAR ENERGY, LTD.Inventors: Kenji NOSHITA, Taichi TAKII, Shingo ODA, Hidehiro IIZUKA
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Patent number: 8320514Abstract: In a nuclear power plant, a corrosion-resistant oxide film on a surface of the metal component of a reactor structure is exposed to a high-temperature water, the corrosion-resistant oxide film containing an oxide having a property of a P-type semiconductor, and a catalytic substance having a property of an N-type semiconductor is deposited on the oxide film. The oxide film maintains the property of the P-type semiconductor.Type: GrantFiled: December 8, 2005Date of Patent: November 27, 2012Assignees: Kabushiki Kaisha Toshiba, The Tokyo Electric Power Company, IncorporatedInventors: Masato Okamura, Tetsuo Oosato, Seiji Yamamoto, Tadasu Yotsuyanagi, Nagayoshi Ichikawa, Kenji Yamazaki, Junichi Takagi, Hidehiro Urata, Shunichi Suzuki, Kenro Takamori, Junichi Suzuki
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Patent number: 8295426Abstract: In a method of reducing corrosion of a material constituting a nuclear reactor structure, an electrochemical corrosion potential is controlled by injecting a solution or a suspension containing a substance generating an excitation current by an action of at least one of radiation, light, and heat existing in a nuclear reactor, or a metal or a metallic compound forming the substance generating the excitation current under the condition in the nuclear reactor to allow the substance generating the excitation current to adhere to the surface of the nuclear reactor structural material, and by injecting hydrogen in cooling water of the nuclear reactor while controlling the hydrogen concentration in a feed water.Type: GrantFiled: December 10, 2004Date of Patent: October 23, 2012Assignees: Kabushiki Kaisha Toshiba, Ishikawajima-Harima Heavy Industries Co., Ltd., The Tokyo Electric Power Company, IncorporatedInventors: Seiji Yamamoto, Tadasu Yotsuyanagi, Nagayoshi Ichikawa, Tetsuo Oosato, Masato Okamura, Junichi Takagi, Kenji Yamazaki, Shunichi Suzuki, Kenro Takamori, Mitsuru Sambongi, Takeshi Shibano, Takashi Hirano, Yuichi Fukaya
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Patent number: 8259893Abstract: A method for underwater packaging of radioactive materials includes creating a vacuum in a cavity of a cleaning device to automatically cause a portion of the cleaning device to move upward to actuate the cleaning device from an open position to a closed position; mounting the cleaning device inside a safe containment area of a transportation and/or storage device; placing the transportation and/or storage device in a pool after filling the safe containment area with water; loading a radioactive material into the safe containment area; closing the transportation and/or storage device using at least one cover; extracting the transportation and/or storage device from the pool; draining the water inside the safe containment area; and creating a pressure differential in the safe containment area to dry the safe containment area, wherein the pressure differential causes the cleaning device to automatically actuate from the closed position to the open position.Type: GrantFiled: March 23, 2010Date of Patent: September 4, 2012Assignee: TN InternationalInventors: Rene Chiocca, Daniel Chanson
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Publication number: 20120063560Abstract: Systems passively eliminate noncondensable gasses from facilities susceptible to damage from combustion of built-up noncondensable gasses, such as H2 and O2 in nuclear power plants, without the need for external power and/or moving parts. Systems include catalyst plates installed in a lower header of the Passive Containment Cooling System (PCCS) condenser, a catalyst packing member, and/or a catalyst coating on an interior surface of a condensation tube of the PCCS condenser or an annular outlet of the PCCS condenser. Structures may have surfaces or hydrophobic elements that inhibit water formation and promote contact with the noncondensable gas. Noncondensable gasses in a nuclear power plant are eliminated by installing and using the systems individually or in combination. An operating pressure of the PCCS condenser may be increased to facilitate recombination of noncondensable gasses therein.Type: ApplicationFiled: September 10, 2010Publication date: March 15, 2012Inventors: Wayne Marquino, Stephan C. Moen, Richard M. Wachowiak, John L. Gels, Jesus Diaz-Quiroz, John C. Burns, JR.
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Publication number: 20100296619Abstract: A safety system for a nuclear plant includes a plurality of catalytic recombiner elements each triggering a recombination reaction with oxygen when hydrogen is entrained in an onflowing gas flow, so that reliable elimination of the hydrogen from the gas mixture is ensured with an especially high degree of operational safety even based on comparatively extreme conditions or scenarios of the aforementioned type. The recombiner elements and/or the flow paths each connecting two recombiner elements on the gas side are configured in such a way that a pressure pulse triggered in the gas medium by an ignition during the recombination reaction in a first recombiner element triggers a gas displacement process having a flow rate of at least 5 m/s in the onflow region of a second, adjacent recombiner element. A nuclear plant with a safety system is also provided.Type: ApplicationFiled: June 11, 2010Publication date: November 25, 2010Applicant: AREVA NP GMBHInventors: Bernd Eckardt, Norbert Losch
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Patent number: 7722834Abstract: The invention relates to a recombiner system (1) for catalytically recombining hydrogen that is produced in energy accumulators or energy converters. The aim of the invention is to provide a recombiner system (1) which can optionally be used for energy accumulator or energy converter systems having different operating conditions and that helps to counteract functional defects. For this purpose, the recombiner system (1) is formed by individual recombiner elements (2) that can be combined with each other in a modular fashion, said recombiner elements (2) comprising at least one respective catalyst (12).Type: GrantFiled: December 23, 2005Date of Patent: May 25, 2010Assignee: Hoppecke Technologies GmbH & Co.Inventors: Bernhard Riegel, Jean Ruch, Eduardo Cattaneo
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Patent number: 7700055Abstract: A hydrogen combustion system comprising: an external cylinder 1 constituting the exterior of a double tube construction; an internal cylinder 2 formed by a porous metal plate constituting the interior of said double tube construction; hydrogen combustion catalyst 4 supported with precious metals on spherical ceramic support surface, formed in pellet state, being packed in said internal cylinder 2; an insert pipe 3 formed by porous metal plate inserted in the center of said internal cylinder 2; pre-heating heaters 5 installed between said insert pipe 3 and said internal cylinder 2 to preheat said hydrogen combustion catalyst 4 to ambient atmosphere of over catalytic reaction temperatures; a hydrogen introducing port 8 connecting to said insert pipe 3; an air introducing port 9 provided at the bottom of said external cylinder 1 in the area between said external cylinder 1 and said internal cylinder 2, wherein air for hydrogen combustion is introduced by the drift effect resulting from the differential pressureType: GrantFiled: July 20, 2007Date of Patent: April 20, 2010Assignee: Chlorine Engineers Corp., Ltd.Inventors: Akiyoshi Manabe, Masaaki Kato, Kazumasa Mochizuki, Masakazu Mimura
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Publication number: 20090225927Abstract: A method and a system for catalytic recombination of hydrogen, which is carried in a gas flow, with oxygen, has the gas flow passed through a reaction zone with a number of catalytic converter elements, with steam being added to the gas flow before it enters the reaction zone. The method and system ensure a particularly high operational reliability of the recombination device, even in varying operating conditions or with varying operating methods, in particular with regard to a hydrogen feed, which is provided as required, in the steam/feed water circuit of the installation. For this purpose, the feed rate of the steam to be added is adjusted in dependence on a measured value which is characteristic of a current actual temperature in the reaction zone.Type: ApplicationFiled: March 9, 2009Publication date: September 10, 2009Applicant: AREVA NP GMBHInventors: Bernd Eckardt, Robert Feuerbach
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Patent number: 7346140Abstract: A photocatalytic substance having the properties of an n-type semiconductor is deposited on a surface of a metal base made of a stainless steel or Inconel. When necessary, the hydrogen concentration of the reactor water is increased. A current produced by the photocatalytic substance when the same is irradiated with light or radioactive rays in a nuclear reactor flows through the metal base to reduce corrosion current. When necessary, the photocatalytic substance is provided on its surface with at least one of Pt, Rh, Ru and Pd.Type: GrantFiled: June 27, 2005Date of Patent: March 18, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Nagayoshi Ichikawa, Yukio Hemmi, Tetsuo Oosato, Junichi Takagi, Kenji Yamazaki
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Publication number: 20070201604Abstract: A steam separator comprises an outer main swirler and an inner auxiliary swirler which is smaller than the main swirler. The swirlers are provided so as to be concentric on the inner wall at the lower side of the first stage inner cylinder. In the steam separator, when the gas-liquid two-phase flow which flows in the vicinity of the axial center of the first stage inner cylinder passes the auxiliary swirler, it is separated into steam and water by the centrifugal force. The separated water (droplets) is introduced into the main swirler. When the separated water (droplets) passes the main swirler, it is separated at the inner wall side of the first stage inner cylinder by the centrifugal force. Pressure loss in a steam separator is reduced and steam separation capability is increased without increasing the moisture from the steam separator.Type: ApplicationFiled: February 28, 2007Publication date: August 30, 2007Inventors: Masao Chaki, Michio Murase, Naoyuki Ishida
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Patent number: 7250143Abstract: The invention concerns a device for spraying water in a feedwater tank of a thermal power plant. Because the spraying device comprises a catalyst for the conversion of the gases contained in the water, the gases released from the water during the spray degasification can be removed easily, reliably and completely. Thus, the degree of efficiency of the thermal circuit of the power plant and the lifespan of the components arranged in the circuit are increased.Type: GrantFiled: February 7, 2005Date of Patent: July 31, 2007Assignee: Balke-Durr GmbHInventors: Günter Grobelny, Robert-Joachim Keck
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Patent number: 7132085Abstract: In a method for catalytic oxidation of a gas, the outlay required is kept at a low level for reliably treating even relatively large quantities of gas and/or high concentrations of the gas fraction that needs to be treated. For this purpose, a gas stream including the gas being treated is circulated through a reaction zone and a return-flow zone, which is in communication with the inlet and outlet sides of the reaction zone. The circulation of the gas stream can be maintained effectively in the form of a passive system if the gas stream which includes the gas to be treated is guided in the upward direction in the reaction zone and the upward flow is assisted by convection resulting from the heat released during the oxidation reaction. Furthermore, the gas stream is preferably cooled locally in the return-flow zone by spray cooling.Type: GrantFiled: February 4, 2003Date of Patent: November 7, 2006Assignee: Framatome ANP GmbHInventor: Bernd Eckardt
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Patent number: 6940939Abstract: A photocatalytic substance having the properties of an n-type semiconductor is deposited on a surface of a metal base made of a stainless steel or Inconel. When necessary, the hydrogen concentration of the reactor water is increased. A current produced by the photocatalytic substance when the same is irradiated with light or radioactive rays in a nuclear reactor flows through the metal base to reduce corrosion current. When necessary, the photocatalytic substance is provided on its surface with at least one of Pt, Rh, Ru and Pd.Type: GrantFiled: June 22, 2000Date of Patent: September 6, 2005Assignee: Kabushiki Kaisha ToshibaInventors: Nagayoshi Ichikawa, Yukio Hemmi, Tetsuo Oosato, Junichi Takagi, Kenji Yamazaki
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Patent number: 6846775Abstract: The invention relates to a catalyst element for a recombinator for eliminating hydrogen from accident atmospheres, in which the technical problem of continuously efficiently converting both small and large amounts of hydrogen with the atmospheric air-oxygen present in the safety containers within a broad concentration range, and routing away the reaction heat arising in the process to such an extent that the respective ignition temperature is not reached in the present mixture is resolved by having the catalyst element exhibit a flat basic body (2), which is arranged within the area of flow through the recombinator, wherein the surface of the basic body (2) over which the accident atmosphere flows has a varying coverage density with catalyst material (3).Type: GrantFiled: November 12, 1999Date of Patent: January 25, 2005Assignee: Forschungszentrum Julich GmbHInventors: Peter Brockerhoff, Werner Von Lensa, Ernst Arndt Reinecke
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Patent number: 6625248Abstract: A process for the treatment of radioactive graphite which includes the following steps: (i) reacting the radioactive graphite at a temperature in the range of from 250° C. to 900° C. with superheated steam or gases containing water vapor to form hydrogen and carbon monoxide; (ii) reacting the hydrogen and carbon monoxide from step (i) to form water and carbon dioxide; and (iii) reacting the carbon dioxide of step (ii) with metal oxides to for carbonate salts. The process enables radioactive graphite, such as graphite moderator, to be treated either in-situ or externally of a decommissioned nuclear reactor.Type: GrantFiled: October 1, 2001Date of Patent: September 23, 2003Assignee: Studsvik, Inc.Inventors: J. Bradley Mason, David Bradbury
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Patent number: 6524534Abstract: An apparatus for removing flammable gas is started only when a concentration change in the flammable gas in a primary containment vessel is detected, so that the decrease in activity of a catalyst due to a catalyst poison is prevented. This apparatus has a catalytic recombining apparatus equipped with a catalyst 1 for reacting the flammable gas, a case 2 that houses the catalyst, and lids 4a and 4b installed at openings 3a and 3b of the case 2. Adhesive parts 5a and 5b which adhere the lids 4a and 4b and the case 2 is melted at high temperatures, and heating elements 6a and 6b composed of an oxidizing catalyst of hydrogen is installed in contact with the adhesive parts 5a and 5b. Thus, the lids are not only closed under normal conditions but opened when the adhesive parts 5a and 5b being melted along with the temperature increase in the surrounding atmosphere.Type: GrantFiled: July 22, 1999Date of Patent: February 25, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Mika Tahara, Yasuo Osawa, Yuji Yamamoto, Kenji Arai, Makoto Harada
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Patent number: 6491877Abstract: A hydrogen/oxygen reaction is initiated in a catalytic recombination or ignition device. The device has one or more catalyst bodies with a predetermined catalytic surface. Only a small portion of the entire available catalytic surface, preferably less than 5% of the surface, is permanently maintained at a temperature level above ambient temperature. The temperature is raised by introducing energy with a heater. The heated surface portion acts as an initial igniter.Type: GrantFiled: March 9, 1999Date of Patent: December 10, 2002Assignee: Framatome ANP GmbHInventors: Bernd Eckardt, Axel Hill
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Publication number: 20020172318Abstract: A device for the catalytic conversion of hydrogen in a containment of a reactor containing a gas mixture. The device includes a recombiner which is disposed in the containment and has a plurality of catalytically active catalyst elements, a first cooling unit which is disposed upstream of the recombiner and cools the gas mixture and a second cooling unit disposed downstream from and behind the recombiner. The device effectively eliminates hydrogen resulting from an accident in the containment, without flashback. The device also suppresses heating of the atmosphere in the containment.Type: ApplicationFiled: May 15, 2002Publication date: November 21, 2002Applicant: FORSCHUNGSZENTRUM JULICH GmbHInventors: Peter Brockerhoff, Wrner Von Lensa, Emst-Arndt Reinecke, Moritz Voswinkel
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Patent number: 6385270Abstract: An ignition system has a plurality of spark igniters for the recombination of hydrogen in a gas mixture. The ignition system provides and ensures reliable early ignition of an ignitable gas mixture, even in the case of comparatively fast gas displacement. Each spark igniter is, according to the invention, configured as a high-speed igniter with an operating frequency in excess of about 10 Hz. In order to ensure reliable ignition of the ignitable gas mixture both in the event of a temporary failure of external units, and when the ignition system has a particularly long operating time, the spark igniters are advantageously connected together in groups for supplying them with energy. Each group of spark igniters is connected to an intermediate energy store common to them, and the intermediate energy stores are connected to a central energy supply unit.Type: GrantFiled: November 29, 1999Date of Patent: May 7, 2002Assignee: Siemens AktiengellschaftInventors: Bernd Eckardt, Axel Hill
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Patent number: 6356613Abstract: An apparatus for the recombination of hydrogen in a gas mixture, in particular for a nuclear power station, during the operation of which unintentional ignition of the gas mixture is avoided in a particularly reliable way. The apparatus contains a catalyst configuration that is disposed in a housing through which the gas mixture can flow by free convection in the operating situation and the catalyst configuration is assigned a flame retention device. In this case, a sediment trap is preferably integrated into the flame retention device, so that hot catalyst particles that become detached from the catalyst configuration are reliably prevented from flowing out counter to the direction of flow of the gas mixture.Type: GrantFiled: August 9, 1999Date of Patent: March 12, 2002Assignee: Siemens AktiengesellschaftInventors: Bernd Eckardt, Axel Hill
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Patent number: 6074882Abstract: In order to determine a concentration of a gas mixture, especially a hydrogen concentration of a containment atmosphere of a nuclear power station, a temperature change resulting from a catalytic reaction is measured. The gas mixture is diluted with a motive gas of known composition. The dilution is carried out by a jet pump.Type: GrantFiled: October 24, 1996Date of Patent: June 13, 2000Assignee: Siemens AktiengesellschaftInventor: Bernd Eckardt
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Patent number: 5773096Abstract: A method of depositing noble metals on surfaces or matrices to manufacture industrial catalysts that can be used in a variety of applications. Such deposition of noble metals can be achieved by treating the surfaces in high-temperature (150.degree. C. or higher) water containing dissolved noble metal ions or its colloidal suspensions. The method consists of the steps of placing the surface of a metal substrate in contact with a volume filled with high-temperature water; injecting a solution of a noble metal compound into the volume for a predetermined duration; and removing the surface of the metal substrate from contact with the high-temperature water after expiration of said predetermined duration. The noble metal compound has the property that it releases species of the noble metal in high-temperature water. These noble metal species deposit on or incorporate in the oxide film on the surface of the metal substrate.Type: GrantFiled: June 7, 1995Date of Patent: June 30, 1998Assignee: General Electric CompanyInventors: Samson Hettiarachchi, Thomas Pompilio Diaz, John Ewing Weber
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Patent number: 5768330Abstract: 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: GrantFiled: October 10, 1996Date of Patent: June 16, 1998Assignee: General Electric CompanyInventors: Peter Louis Andresen, Samson Hettiarachchi, Young Jin Kim, Thomas Pompilio Diaz
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Patent number: 5740217Abstract: An improved system for passively removing hydrogen inside containment in a nuclear reactor in the event of a loss of coolant accident by means of catalytic hydrogen recombination. A baffle wall located inside containment is used to establish within containment an air upflow path and an air downflow path in convective exchange. The air upflow is past the area of the coolant lines and is effective to entrain hydrogen from the break and the air downflow path is in the area adjacent the containment wall. The air upflow path downstream of the coolant lines is ducted so as to confine the entrained hydrogen to the ducted air upflow path and catalytic hydrogen recombiners are located in the ducted air upflow path for recombining said entrained hydrogen with oxygen in said ducted air upflow.Type: GrantFiled: May 15, 1997Date of Patent: April 14, 1998Assignee: Atomic Energy of Canada LimitedInventor: Norman J. Spinks
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Patent number: 5733520Abstract: In a boiling water reactor having two extraction systems, one in use and the other held as a backup, a method and apparatus for extracting condenser exhaust gases of the reactor include a preheater for heating condenser gases which are then used for heating a recombiner of the extraction system. Auxiliary steam from the turbine is directed to the preheater for heating the condenser gases. A bypass line bypasses a valve in the auxiliary steam pipeline from the turbine to the preheater. The operating extraction system receives heating steam through the auxiliary pipeline, while the backup extraction system has the valve in the auxiliary steam pipeline closed. The recombiner of the backup extraction system is kept heated by guiding steam through the bypass line to the preheater, where the steam expands and is thereby heated, and directing the expanded steam through a vent line to the recombiner.Type: GrantFiled: January 16, 1996Date of Patent: March 31, 1998Assignee: Asea Brown Boveri AGInventors: Francisco Blangetti, Alfredo Galvagno
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Patent number: 5592521Abstract: A first partial flow of an H.sub.2 -air-steam mixture is passed through a first channel and recombined by contact with a first channel wall having a catalytic coating. In addition to the first partial flow, a second partial flow of the mixture is passed through a second channel having a second channel wall and is ignited by being fed past preferably metallic ignition elements being heated to the H.sub.2 ignition temperature upon reaching or exceeding an ignition limit. Under these circumstances, heat liberated during the catalytic reaction in the first channel is at least partially transmitted to the second channel for the purpose of preheating it. The novel process functions both at the lower and at the upper ignition limit and recombines even at unignitable H.sub.2 concentrations. A device with which the process can be carried out is also described.Type: GrantFiled: June 7, 1995Date of Patent: January 7, 1997Assignee: Siemens AktiengesellschaftInventor: Axel Hill
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Patent number: 5515406Abstract: A passive catalytic ammonia converter operating in the water/steam mixture exiting the core of a boiling water reactor. The catalytic ammonia converter is made of catalytic material arranged and situated such that substantially all of the water/steam mixture entering the water/steam separator device flows over the surface of the catalytic material. The catalytic surfaces react ammonia and/or NO with O.sub.2 or H.sub.2 O.sub.2 in the water/steam mixture to form nitrite or nitrate. The passive catalytic ammonia converter is constructed to ensure that the pressure drop of the reactor water across the device is very small. The catalytic ammonia converter can include a plurality of stainless steel flow-through housings packed with catalytic ammonia converter material, which could take the form of tangled wire or strips, crimped ribbon, porous sintered metal composite or any other structure having a high surface area-to-volume ratio.Type: GrantFiled: May 21, 1993Date of Patent: May 7, 1996Assignee: General Electric CompanyInventors: Robert L. Cowan, II, Gerald M. Gordon, Robert J. Law, Beth A. McAllister
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Patent number: 5499279Abstract: An apparatus for removing free hydrogen from a gas mixture containing essentially hydrogen, oxygen, and steam using a catalyst arrangement for catalytically supported oxidation of hydrogen and a hydrogen-storage apparatus for absorption of hydrogen by hydride formation. The catalyst arrangement and the hydrogen-storage apparatus are designed to operate in different temperature and pressure regions, and they are arranged to provide good heat conduction between them. In this manner, heat generated by hydride formation enhances catalytic oxidation.Type: GrantFiled: December 5, 1994Date of Patent: March 12, 1996Assignee: Gesellschaft fur Anlagen- und ReaktorsicherheitInventor: Amiya K. Chakraborty
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Patent number: 5495511Abstract: A device for passively inerting the gas mixture forming in the reactor containment of a nuclear power plant in an accident situation is proposed, which device is based on the use of chemical substances which react or disintegrate, releasing an inerting gas or gas mixture when a certain temperature of reaction is reached. This device is especially suitable for use in connection with catalytic recombiners for removing hydrogen through oxidation with the oxygen present. The heat resulting from this exothermic process of recombination can be put to use for heating up chemical substances to the required temperature, these having temperatures of reaction that lie above the temperature (approximately 100.degree. C.) that develops in the reactor containment in an accident situation.Type: GrantFiled: August 18, 1994Date of Patent: February 27, 1996Assignee: Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) mbHInventor: Amiya K. Chakraborty
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Patent number: 5492686Abstract: A first partial flow of an H.sub.2 -air-steam mixture is passed through a first channel and recombined by contact with a first channel wall having a catalytic coating. In addition to the first partial flow, a second partial flow of the mixture is passed through a second channel having a second channel wall and is ignited by being fed past preferably metallic ignition elements being heated to the H.sub.2 ignition temperature upon reaching or exceeding an ignition limit. Under these circumstances, heat liberated during the catalytic reaction in the first channel is at least partially transmitted to the second channel for the purpose of preheating it. The novel process functions both at the lower and at the upper ignition limit and recombines even at unignitable H.sub.2 concentrations. A device with which the process can be carried out is also described.Type: GrantFiled: January 28, 1994Date of Patent: February 20, 1996Assignee: Siemens AktiengesellschaftInventor: Axel Hill
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Patent number: 5473646Abstract: A device for the recombination of hydrogen and oxygen includes catalyst bodies having surfaces and a catalytic coating on the surfaces over which a gas and vapor mixture containing hydrogen to be eliminated is to be conducted. A casing which surrounds and retains the catalyst bodies has at least one permanently open gas inlet aperture and one permanently open gas outlet aperture, and a gas flow path in the casing through which the apertures communicate. The catalyst bodies are disposed downstream of the gas inlet aperture in the gas flow path. The catalyst bodies are flat bodies formed of multi-layered sheet metal in a multi-channel configuration forming a plurality of mutually parallel gas flow channels. Some of the gas flow channels have channel cross sections being defined by at least an adjacent two of the flat bodies being spaced-apart, and the gas flow channels at ends of the configuration have channel cross sections being defined by at least one of the flat bodies.Type: GrantFiled: March 30, 1994Date of Patent: December 5, 1995Assignee: Siemens AktiengesellschaftInventors: Reinhard Heck, Karl-Heinz Schwenk
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Patent number: 5392325Abstract: A catalytic recombiner device for reacting two or more molecular species having dilute concentrations in fluids flowing in pipes at elevated temperatures. The species are stable in the bulk fluid, but because of a high electrochemical potential, the species create conditions favorable to stress corrosion cracking in the pipe walls. If the pipe forms a portion of a coolant system, as in a nuclear power plant, the dissolved chemical species are transported and distributed throughout the system with undesirable consequences. To reduce the electrochemical potential, a cartridge having catalytic surfaces is installed in the flow upstream of the component to be protected against stress corrosion cracking. The catalytic surfaces of the cartridge form a small amount of benign reaction product (e.g. water), thereby reducing the concentration of undesirable species.Type: GrantFiled: May 21, 1993Date of Patent: February 21, 1995Assignee: General Electric CompanyInventors: Gerald M. Gordon, Beth Ann McAllister, James H. Terhune, James E. Charnley
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Patent number: 5321730Abstract: A process for oxidation of hydrogen in a containment of a nuclear reactor plant with the aid of finely distributed catalyst particles, includes spraying catalyst particles in the form of a solution or suspension inside or outside the containment. The sprayed solution or suspension is subsequently dried by heating inside or outside the containment to produce aerosols. The aerosols produced outside are introduced into the containment. A device for oxidation of hydrogen in a containment of a nuclear reactor plant with the aid of finely distributed catalyst particles includes a container for receiving catalyst particles in the form of a solution or suspension. A distributor configuration is connected to the container for spraying the solution or suspension inside or outside the containment. A heater dries the sprayed solution or suspension before the solution or suspension is released into the containment.Type: GrantFiled: December 16, 1992Date of Patent: June 14, 1994Assignee: Siemens AktiengesellschaftInventor: Bernd Eckardt
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Patent number: 5301217Abstract: A device for the recombination of hydrogen and oxygen includes catalyst bodies having surfaces and a catalytic coating on the surfaces over which a gas and vapor mixture containing hydrogen to be eliminated is to be conducted. A casing which surrounds and retains the catalyst bodies has at least one permanently open gas inlet aperture and one permanently open gas outlet aperture, and a gas flow path in the casing through which the apertures communicate. The catalyst bodies are disposed downstream of the gas inlet aperture in the gas flow path. The catalyst bodies are flat bodies formed of multi-layered sheet metal in a multi-channel configuration forming a plurality of mutually parallel gas flow channels. Some of the gas flow channels have channel cross sections being defined by at least an adjacent two of the flat bodies being spaced-apart, and the gas flow channels at ends of the configuration have channel cross sections being defined by at least one of the flat bodies.Type: GrantFiled: November 12, 1992Date of Patent: April 5, 1994Assignee: Siemens AktiengesellschaftInventors: Reinhard Heck, Karl-Heinz Schwenk
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Patent number: 5287392Abstract: An internal passive catalytic device operating in the water phase of a boiling water reactor vessel downstream of the steam/water separator location. The device consists of catalytic material arranged and situated such that all (except perhaps a small leakage flow) water phase exiting the water/steam separator device flows over the surface of the catalytic material. The catalytic surfaces decompose dissolved hydrogen peroxide into water and oxygen. When the substrate of the catalytic material is plated or alloyed with a water recombination catalyst such as a noble metal, the catalytic surfaces also catalyze the recombination of dissolved hydrogen and oxygen molecules into water. The passive catalytic device is constructed to ensure that the pressure drop of the reactor water across the device is very small.Type: GrantFiled: November 25, 1992Date of Patent: February 15, 1994Assignee: General Electric CompanyInventors: Robert Lee Cowan II, Robert J. Law, James E. Charnley, Robert J. Brandon
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Patent number: 5285486Abstract: A passive decomposer operating in the water/steam mixture exiting the core of a boiling water reactor. The decomposer comprises a catalytic material arranged and situated such that substantially all of the water/steam mixture entering the water/steam separator device flows over the surface of the catalytic material. The catalytic decomposing surfaces decompose hydrogen peroxide molecules dissolved in the liquid phase to form water and oxygen molecules. The passive catalytic decomposer is constructed to ensure that the pressure drop of the reactor water across the device is very small. The decomposer can include a plurality of stainless steel flow-through housings packed with stainless steel catalytic decomposer material, which could take the form of tangled wire or strips, crimped ribbon, porous sintered metal composite or any other structure having a high surface area-to-volume ratio.Type: GrantFiled: November 25, 1992Date of Patent: February 8, 1994Assignee: General Electric CompanyInventors: Robert L. Cowan, II, Robert J. Law, James E. Charnley
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Patent number: 5230859Abstract: To ensure safe removal of flammable explosive gaseous mixtures, the flammable mixtures are burned and/or recombined in partial volumes of the container separated from the rest of the container by metal grilles (18,19). The combustion is thereby prevented from spreading by the principle of the Davy safety lamp. The combustion and/or recombination in the partial volumes is effected by means of ignition sources (20), such as electric sparks, hot surfaces, open flames and/or catalytic surfaces. The heat energy released during combustion is transferred by means of cooling devices such as heat pipes. The temperature of the grille is sued to control the energy supply of the ignition source(s) and should never exceed approximately 2/3 of the ignition temperature of the flammable gaseous mixture; when the temperature reaches 3/4 of the ignition temperature, a fuse cuts off the energy supply. If the grille suffers mechanical damage, it touches an electrically insulated internal grille.Type: GrantFiled: December 14, 1990Date of Patent: July 27, 1993Inventor: Johannes Wiesemes
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Patent number: 5167908Abstract: A device for recombination of hydrogen and oxygen with the aid of a catalyst system comprises the catalyst system in a housing 1, which has at least one inlet opening and at least one outlet opening, which are sealed by means of first seals 7 which open as a function of temperature. In this housing, a gas-permeable filter system is also provided in such a manner that after opening of the first seals, the gases or gas mixtures entering the inlet opening do not reach the catlayst system until they have first passed through the filter system. The filter system is essentially impermeable to aerosols and grease.Type: GrantFiled: February 18, 1992Date of Patent: December 1, 1992Assignee: Gesellschaft Fur Reaktorsicherheit (GRS)Inventor: Amiya K. Chakraborty
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Patent number: 5130079Abstract: An apparatus for removing hydrogen from a mixture of gases containing hydrogen, oxygen, steam, and aerosols, with a catalyst arrangement composed of a substrate coated with a material which catalyzes the oxidation of hydrogen while releasing heat. The apparatus is characterized by a protective device which encloses a catalyst arrangement until a preset temperature is reached. Once the preset temperature is reached, the apparatus is automatically movable into a position which exposes the catalyst arrangement, with the protective device being permeable to gas pressure but essentially impermeable to aerosols. Consequently, the catalyst arrangement is protected against deposition of aerosols contained in the gas mixture until the preset temperature is reached.Type: GrantFiled: January 8, 1991Date of Patent: July 14, 1992Assignee: Gesellschaft Fur Reaktorsicherheit (GRS) mbHInventor: Amiya K. Chakraborty
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Patent number: 5108714Abstract: An exhaust gas recombiner for restoring hydrogen and oxygen gases in gases extracted from a condenser of a steam engine into water by reaction of the hydrogen and oxygen gases includes a vertical cylinder vessel having an extracted gas inlet at its lower end and an outlet at its upper end. A diameter of the vessel is substantially the same as that of an outlet piping connected to the outlet of the vessel for introducing gases leaving the vessel into an exhaust gas condenser. The apparatus further includes a plurality of units in the vessel. Each unit has a honeycomb structure for flow-rectifying gases flowing into the vessel through the extracted gas inlet and a honeycomb catalyst gas carrying on its surfaces a catalyst being positioned on an upper side of the honeycomb structure.Type: GrantFiled: September 13, 1990Date of Patent: April 28, 1992Assignee: NGK Insulators, Ltd.Inventors: Katsuichi Iwata, Magoji Okamoto