Patents by Inventor Keizou Ohtsuka

Keizou Ohtsuka 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: 5563003
    Abstract: Molten carbonate type or phosphoric acid type fuel cells and a method for supplementing these fuel cells with an electrolyte are disclosed. A fuel cell having an extended life is provided by scattering a plurality of sealed supplementary electrolyte containers made of a material which is soluble in the electrolyte at elevated temperatures, and supplying the supplementary electrolyte from the dissolved containers to the fuel cell while the cell is working.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: October 8, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Hiroaki Suzuki, Keizou Ohtsuka, Toshiki Kahara, Tadashi Yoshida
  • Patent number: 5213909
    Abstract: A fuel cell has a plurality of fuel cell sub-stacks each of which has cell bodies, at least one anode header and at least one cathode header and which are stacked to form a fuel cell stack body, and side thermal insulators which are provided on the side of the fuel cell stack body so as to keep the fuel cell sub-stacks warm and which are discrete from each other in the direction of stacking of the fuel cell sub-stacks, each of the plurality of side thermal insulators being independently supported.
    Type: Grant
    Filed: April 23, 1992
    Date of Patent: May 25, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Sei Takashima, Keizou Ohtsuka, Toshiki Kahara, Yasutaka Komatsu
  • Patent number: 5212022
    Abstract: The invention relates to internal-reforming fuel cells. They are each constructed of plural unit cells stacked one over another. Each unit cell is formed of a cathode, an electrolyte plate, an anode and a separator. Each unit cell also includes a generating zone formed by the cathode, anode and electrolyte plate; a reforming zone for reforming fuel gas; a fuel gas flow channel communicating with a fuel gas inlet and a fuel gas outlet and including a divided fuel gas flow channel for the unit cell; and an oxidant gas flow channel communicating with an oxidant gas inlet and an oxidant gas outlet and including a divided oxidant gas flow channel for the unit cell. The reforming zone is arranged in the fuel gas flow channel while the generating zone is arranged in contact with the fuel gas flow channel and the oxidant gas flow channel at a position downstream of the reforming zone while the fuel gas and oxidant gas are maintained separated from each other.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: May 18, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Takahashi, Keizou Ohtsuka, Toshiki Kahara, Yasutaka Komatsu
  • Patent number: 4902587
    Abstract: The present invention provides a fuel cell which is improved in creep resistance and sintering resistance of anode and in activity of anode and which can maintain high performance over a long time. This fuel cell comprises a laminate comprising an electrolyte holding material having pores for holding an electrolyte, an anode and a cathode which sandwich the electrolyte holding material and a separator provided with grooves for feeding a gas to the anode and cathode characterized in that the anode is a ternary anode which comprises nickel as a main component and additionally cobalt and chromium oxide.
    Type: Grant
    Filed: January 11, 1989
    Date of Patent: February 20, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiro Saitoh, Keizou Ohtsuka, Shuhei Yamaguchi, Toshiki Kahara
  • Patent number: 4781996
    Abstract: The fuel cell of this invention has the following electrolyte plate and separator plate.An electrolyte plate made of ceramics which is interposed between an anode and a cathode which are arranged opposite to each other.A separator plate which is laminated on the back surface of each of the anode and cathode and which is made of such a material and in such a composition that the expansion coefficient thereof is nearly equal to that of the electrolyte plate.According to the above construction, tensile stress applied to the electrolyte plate due to a change in temperature can be reduced and cracking of the electrolyte plate which may occur with lapse of time can be prevented.
    Type: Grant
    Filed: June 12, 1987
    Date of Patent: November 1, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Hajime Toriya, Akio Sohma, Keizou Ohtsuka
  • Patent number: 4741279
    Abstract: A method of combusting a coal-water mixture fuel. The mixture is atomized into a conically-shaped primary pre-combustion chamber. Primary air is supplied, at a rate smaller than that required for complete burning of the mixture and in the form of a swirl about the axis of the jet of the atomized mixture, from the peripheral portion of the primary pre-combustion chamber into a secondary pre-combustion chamber connected to said primary pre-combustion chamber, thus forming a region of low pressure around the jet of the mixture. The region of low pressure serves to induce the atmosphere gas from the secondary pre-combustion chamber of higher temperature back into the primary pre-combustion chamber of a lower temperature, so that the water content of the mixture is evaporated and the mixture is ignited by the heat of the hot atmosphere gas.
    Type: Grant
    Filed: January 7, 1987
    Date of Patent: May 3, 1988
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha
    Inventors: Shigeru Azuhata, Kazutoshi Higashiyama, Kiyoshi Narato, Hironobu Kobayashi, Norio Arashi, Tooru Inada, Kenichi Sohma, Keizou Ohtsuka, Yoshitaka Takahashi, Fumio Koda, Tadahisa Masai, Masakiyo Tanikawa, Kei Kawano
  • Patent number: 4653998
    Abstract: A furnace system connected to a burner including a furnace for burning a fuel and air ejected from the burner into the furnace to produce a flame therein, and a combustion condition determining device for determining the conditions of combustion of the fuel in a zone of the flame extending along different strata thereof by collecting light in the flame at one point in the flame by moving such point. Signals outputted by the combustion condition determining device are utilized for monitoring or controlling the flame and controlling exhaust emission control devices for controlling exhaust emissions produced by the combustion of the fuel. Control of the conditions of combustion of the flame can be effected quickly with a high degree of precision by monitoring the flame.
    Type: Grant
    Filed: January 25, 1985
    Date of Patent: March 31, 1987
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha
    Inventors: Ken-ichi Sohma, Norio Arashi, Shigeru Azuhata, Kiyoshi Narato, Tooru Inada, Hironobu Kobayashi, Keizou Ohtsuka, Yukio Hishinuma
  • Patent number: 4515094
    Abstract: There are the primary fuel nozzle for jetting the first coal in the fine powder form with an air ratio up to 1, and the secondary fuel nozzle for jetting the second coal in the fine powder form with an air ratio at least 1 from the outer circumferential portion of the primary fuel nozzle. Swirl means are located at the top of the secondary fuel nozzle for swirling the second coal.
    Type: Grant
    Filed: December 12, 1983
    Date of Patent: May 7, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Shigeru Azuhata, Norio Arashi, Kiyoshi Narato, Tooru Inada, Kenichi Souma, Keizou Ohtsuka, Yukio Hishinuma, Tadahisa Masai
  • Patent number: 4436699
    Abstract: A monitoring system for checking an electric rotary machine for local overheating including a sensing device for sensing the concentration of minuscule particles in a gas serving as coolant for the machine, and a supply device for supplying to the sensing device a test gas containing minuscule particles of gasifiable liquid. The test gas is supplied to the sensing device by the supply device to permit the sensing device to perform a sensing operation, so as to determine whether or not the sensing device is functioning normally.
    Type: Grant
    Filed: June 8, 1981
    Date of Patent: March 13, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Kiyoshi Narato, Keizou Ohtsuka, Tooru Inada, Takashi Watanabe
  • Patent number: 4364032
    Abstract: In a gas cooled rotary electric machine using insulating coating material which is subjected to thermal-decomposition when the insulating coating material is exposed to high temperatures thereby generating submicron particles, the concentration in the cooling gas of submicron particles generated through thermal-decomposition of the insulating coating material and distributed in the cooling gas is detected and an alarm signal is issued when the time-integration of a signal representing the concentration of the submicron particles exceeds a predetermined reference integration value.
    Type: Grant
    Filed: December 4, 1980
    Date of Patent: December 14, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Kiyoshi Narato, Keizou Ohtsuka, Sadahiko Niwa