Patents by Inventor Koichiro Iwashita

Koichiro Iwashita 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: 8292992
    Abstract: A flue gas desulfurization apparatus includes an absorption tower that absorbs sulfur oxide in a flue gas, and drift suppression members that are arranged near a bend portion of a purified gas exhaust passage arranged at an outlet portion of the absorption tower, the drift suppression members serving to collect mist particles.
    Type: Grant
    Filed: January 29, 2008
    Date of Patent: October 23, 2012
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Toshihiro Sato, Manabu Oda, Koichiro Iwashita, Eiji Ochi, Susumu Okino, Takeo Shinoda, Tetsu Ushiku
  • Publication number: 20090188393
    Abstract: A flue gas desulfurization apparatus includes an absorption tower that absorbs sulfur oxide in a flue gas, and drift suppression members that are arranged near a bend portion of a purified gas exhaust passage arranged at an outlet portion of the absorption tower, the drift suppression members serving to collect mist particles.
    Type: Application
    Filed: January 29, 2008
    Publication date: July 30, 2009
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Toshihiro SATO, Manabu ODA, Koichiro IWASHITA, Eiji OCHI, Susumu OKINO, Takeo SHINODA, Tetsu USHIKU
  • Publication number: 20070187849
    Abstract: Provided is an exhaust gas treating tower in which exhaust gas flow velocity is increased more than a prior art case so that exhaust gas treating efficiency can be enhanced or the exhaust gas treating tower can be made compact if equivalent performance is to be maintained. Also, an exhaust gas treating tower ensuring a liquid recovery is provided. In an exhaust gas treating tower 10A, liquid columns C are generated and also a liquid drop generating member 20 is provided to thereby generate liquid drops M therearound to be floated. Also, liquid is spouted from spray nozzles to thereby generate liquid films F in area different from the liquid columns C. In an exhaust gas treating tower 110, a liquid drop eliminator 120 is provided upstream of a mist eliminator 118. Interval P1 of collecting plates 121 of the liquid drop eliminator 120 is made larger than interval P2 of collecting plates 119 of the mist eliminator 118.
    Type: Application
    Filed: April 9, 2007
    Publication date: August 16, 2007
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Kenichi Okada, Toru Takashina, Susumu Okino, Naoyuki Kamiyama, Tsumoru Nakamura, Shintaro Honjo, Kouzou Takano, Tsuyoshi Oishi, Koichiro Iwashita
  • Publication number: 20050046052
    Abstract: Provided is an exhaust gas treating tower in which exhaust gas flow velocity is increased more than a prior art case so that exhaust gas treating efficiency can be enhanced or the exhaust gas treating tower can be made compact if equivalent performance is to be maintained. Also, an exhaust gas treating tower ensuring a liquid recovery is provided. In an exhaust gas treating tower 10A, liquid columns C are generated and also a liquid drop generating member 20 is provided to thereby generate liquid drops M therearound to be floated. Also, liquid is spouted from spray nozzles to thereby generate liquid films F in area different from the liquid columns C. In an exhaust gas treating tower 110, a liquid drop eliminator 120 is provided upstream of a mist eliminator 118. Interval P1 of collecting plates 121 of the liquid drop eliminator 120 is made larger than interval P2 of collecting plates 119 of the mist eliminator 118.
    Type: Application
    Filed: June 25, 2004
    Publication date: March 3, 2005
    Inventors: Kenichi Okada, Toru Takashina, Susumu Okino, Naoyuki Kamiyama, Tsumoru Nakamura, Shintaro Honjo, Kouzou Takano, Tsuyoshi Oishi, Koichiro Iwashita
  • Publication number: 20030170159
    Abstract: An apparatus for removing mercury from a waste gas comprises a catalytic oxidizing apparatus in which the metal mercury in a combustion waste gas containing SOx and mercury is oxidized into mercury chloride under the reaction temperature not higher than 300° C. in the presence of a solid catalyst, a wet desulfurizing apparatus for removing mercury by using an alkaline absorbing solution, and a temperature control apparatus for controlling the reaction temperature in oxidizing the metal mercury into mercury chloride.
    Type: Application
    Filed: April 7, 2003
    Publication date: September 11, 2003
    Inventors: Shintaro Honjo, Toru Takashina, Kozo Iida, Tetsuya Imai, Koichiro Iwashita, Tatsuto Nagayasu
  • Patent number: 6254771
    Abstract: This invention relates to a method for the treatment of a desulfurization absorbing fluid after gas-liquid contact with combustion exhaust gas in which fine particles of unburned carbon and other materials are efficiently removed from the desulfurization absorbing fluid to improve the quality of a by-product (e.g., gypsum) obtained therefrom. The method of this invention comprises the steps of feeding a gas into a desulfurization absorbing fluid (A) containing fine particles of unburned carbon and other materials and thereby producing gas bubbles so as to cause the fine particles to adhere to the surfaces of the gas bubbles and create a foam phase (D) consisting of the gas bubbles; and breaking the foam phase (D) to obtain a liquid (E) containing the fine particles.
    Type: Grant
    Filed: August 4, 1999
    Date of Patent: July 3, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Koichiro Iwashita, Takeo Shinoda, Masakazu Onizuka, Masao Hino, Kenji Inoue
  • Patent number: 6203598
    Abstract: This invention relates to a flue gas treating process including a heat recovery step for recovering heat from flue gas by means of a heat exchanger (4) and thereby cooling the flue gas, and a subsequent absorption step for bringing the flue gas into gas-liquid contact with an absorbing fluid (D) in absorption towers (12, 13) so as to remove at least SO2 present in the flue gas by absorption into the absorbing fluid (D), which is characterized, for example, in that a powder addition step for spraying a powder collectable in the absorption step into the flue gas is provided prior to the heat recovery step. This invention makes it possible to provide a flue gas treating process in which a countermeasure against SO3 present in flue gas can be easily achieved without resorting to ammonia injection and the flue gas can further be purified without the disadvantage of causing the injected substance to remain in the treated flue gas.
    Type: Grant
    Filed: February 8, 1999
    Date of Patent: March 20, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Shigeo Hasegawa, Naohiko Ukawa, Susumu Okino, Koichiro Iwashita, Kazuaki Kimura, Atsushi Yoshioka, Yoshimitsu Kawanishi, Shoichi Onishi, Toru Takashina, Toyoshi Nakagawa
  • Patent number: 6168721
    Abstract: The present invention relates to a process for the treatment of arsenic-containing sludge obtained by adjusting arsenic-containing waste water to a PH of 12 or greater by the addition of a calcium compound and subjecting the waste water to solid-liquid separation, the process comprising the steps of adding a calcium compound to the arsenic-containing sludge slurry obtained by the solid-liquid separation, dewatering the resulting sludge, drying the dewatered sludge, and calcining the dried sludge. According to the present invention, arsenic-containing sludge obtained by treating waste water to precipitate arsenic present therein can be calcined to yield a calcined product which involves no risk of arsenic redissolution when it is dumped. Moreover, there is no possibility that arsenic compounds may be volatilized during calcination.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: January 2, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Satoru Sugita, Taku Shimizu, Koichiro Iwashita, Hiroshi Baba, Hideki Kamiyoshi, Morikata Nishida
  • Patent number: 6138378
    Abstract: This invention is related to a wet gas process which would not require a spray pump, and which would allow the absorption liquid to be recovered smoothly even if the flow velocity of the gases entrained to the liquid should decrease. A wet gas processing apparatus in which the absorption liquid collected in the first liquid storage tank is sprayed in a specified direction (which may be upward, horizontal or downward) by a discharge unit consisting of spray nozzles (14) or the like in the absorption tower. The sprayed liquid is brought into contact with the exhaust gases which are conducted into the tower, and the targeted components of the gases are absorbed and removed. This processing apparatus is distinguished by the following. The first liquid storage tank for the absorption liquid comprises a pressure tank (11) which generates a pressurized gas in the space above the surface of the collected liquid (11a).
    Type: Grant
    Filed: September 8, 1999
    Date of Patent: October 31, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Toru Takashina, Naoyuki Kamiyama, Takeo Shinoda, Hiromitsu Nagayasu, Susumu Okino, Masakazu Onizuka, Koichiro Iwashita, Satoshi Nakamura, Kenji Inoue
  • Patent number: 6096279
    Abstract: Flue gas is treated for the presence of SO.sub.3, without resorting to ammonia injection, by adding a powder into the flue gas and subsequently bringing the flue gas into gas-liquid contact with an absorbing fluid, whereby the SO.sub.2 present in the flue gas is removed by absorption into the absorbing fluid. The treatment process may also include introducing the flue gas into a dust collector, whereby dust, including the powder present in the flue gas, is collected, and/or recovering heat from the flue gas by means of a heat exchanger, whereby the flue gas is cooled. A system for treating flue gas is also provided.
    Type: Grant
    Filed: March 3, 1998
    Date of Patent: August 1, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Koichiro Iwashita, Kazuaki Kimura, Toyoshi Nakagawa, Naohiko Ukawa, Susumu Okino, Kiyoshi Okazoe
  • Patent number: 6051055
    Abstract: An exhaust gas desulfurization system includes a spray pipe which is provided with a plurality of nozzles in the lengthwise direction and whose one end is closed and arranged horizontally in an absorption tower through which the exhaust gas passes vertically. Absorbent slurry is fed from the other end of the spray pipe and is injected upward from the nozzles, by which absorbent slurry is brought into contact with the exhaust gas to perform treatment in the absorption tower. The flow passage on the closed end side of the pipe is present in a shape such that the flow passage cross-sectional area decreases toward the closed end.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: April 18, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Naohiko Ukawa, Toru Takashina, Susumu Okino, Kazuaki Kimura, Koichiro Iwashita, Kouji Ikeda, Heiji Tanaka
  • Patent number: 6029100
    Abstract: There is provided a method for flue gas desulfurization which is capable of conducting minute control of oxidation and which is capable of maintaining the concentration of sulfurous acid in an absorbent liquid within a proper range in a highly reliable and efficient manner, even in the case where an abrupt change occurs in the operational conditions of the system. In the method for controlling the oxidation in flue gas desulfurization, the value of proportional sensitivity K in the feed back control process, which is based primarily on the oxidation-reduction potential, is increased depending on the deviation .epsilon. in a region where the detected oxidation reduction potential value PN is below the target oxidation reduction potential value SN in correspondence with the characteristic change of the oxidation-reduction potential against the concentration of sulfurous acid.
    Type: Grant
    Filed: February 11, 1997
    Date of Patent: February 22, 2000
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Koichiro Iwashita, Susumu Okino, Naohiko Ukawa, Masaru Sakamoto
  • Patent number: 5958335
    Abstract: A corrosion preventive method and an apparatus for preventing corrosion of stainless steel components in an exhaust gas desulfurizing apparatus of an exhaust gas treatment system comprising the exhaust gas desulfurizing apparatus for removing at least sulfur dioxide by bringing exhaust gas into contact with absorbing solution, wherein specific means is employed to maintain the Cl.sup.- concentration and SO.sub.4.sup.2- concentration at a corrosion preventive side of the corrosion resisting limit of stainless steel.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: September 28, 1999
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Kiyoshi Okazoe, Yoshio Nakayama, Koichiro Iwashita, Atsushi Tatani, Shigeo Hasegawa
  • Patent number: 5879639
    Abstract: A wet flue gas desulfurization system for removing sulfur dioxide present in flue gas by absorption into an absorbent slurry includes an absorption tower having at a bottom thereof a tank for holding an absorbent slurry; a circulating pump for feeding the absorbent slurry within the tank to a flue gas inlet section in an upper part of the absorption tower and bringing the absorbent slurry into contact with flue gas; and a slurry preparation compartment provided on one side of the tank of the absorption tower and separated from a flue gas passage section by a partition wall having its lower end submerged below a surface of the absorbent slurry, whereby an absorbent and water constituting the absorbent slurry are directly introduced into the slurry preparation compartment.
    Type: Grant
    Filed: December 9, 1996
    Date of Patent: March 9, 1999
    Assignee: Mitsubishi Jukogyn Kabushiki Kaisha
    Inventors: Atsushi Tatani, Kiyoshi Okazoe, Yoshio Nakayama, Koichiro Iwashita
  • Patent number: 5878675
    Abstract: A flue gas desulfurizer having an absorption tower for bringing untreated flue gas into gas-liquid contact with an absorbent slurry, wherein there is provided heat recovery means for recovering heat from the flue gas passing through the flue gas inlet section of the absorption tower prior to gas-liquid contact, and to boiler equipment including heat release means for releasing the recovered heat to heat utilization equipment. This invention also relates to thermal electric power generation equipment including extraction feedwater heaters for heating boiler feedwater with steam from steam turbines, a flue gas desulfurizer using an absorbent slurry, and means for recovering heat from the flue gas passing through the flue gas desulfurizer and/or the absorbent slurry within the flue gas desulfurizer, whereby boiler feedwater is preheated by the recovered heat and then introduced into the extraction feedwater heaters.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: March 9, 1999
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Masaki Iijima, Atsushi Tatani, Kazuaki Kimura, Koichiro Iwashita, Satoshi Yajima, Toru Takashina, Susumu Okino
  • Patent number: 5840263
    Abstract: A flue gas treating system for removing sulfur dioxide and dust present in flue gas by gas-liquid contact with an absorbing fluid and has an inlet side absorption tower of the liquid column type and an outlet side absorption tower of the liquid column type, each of which has a uniform cross-section over the area of gas-liquid contact, and the cross-section of flue gas in the inlet side absorption tower is smaller than the cross section of flue gas in the outlet side absorption tower. The inlet side absorption tower is constructed in the form of a parallel-flow absorption tower wherein the flue gas flows downward for favorable collection of dust and absorption of sulfur dioxide. The outlet side absorption tower is constructed in the form of a counter-flow adsorption tower wherein the flue gas flows upward for favorable absorption of sulfur dioxide. The absorbing fluid within a tank is injected upward from a plurality of spray pipes.
    Type: Grant
    Filed: May 5, 1997
    Date of Patent: November 24, 1998
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Takeo Shinoda, Tamotsu Higuchi, Shinichiro Kotake, Kiyoshi Okazoe, Tatsuto Nagayasu, Koichiro Iwashita, Kenichiro Kawamichi, Susumu Okino, Toru Takashina
  • Patent number: 5785901
    Abstract: An object of this invention is to provide a gas-liquid contact apparatus for use in wet flue gas desulfurizers and the like which is equipped with lightweight and inexpensive header pipes having excellent wear resistance and corrosion resistance and hence exhibits high reliability and economical efficiency. To this end, there is provided a gas-liquid contact apparatus wherein one or more header pipes having attached thereto a plurality of spray nozzles for spouting a slurry upward are disposed in the main body of a tower through which a gas flows, characterized in that the header pipes are made of a fiber-reinforced resin composite material and the outer surface thereof or the outer and inner surfaces thereof are formed of a corrosion-resistant and wear-resistant layer of a resin containing ceramic particles.
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: July 28, 1998
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Shigeo Hasegawa, Noohiko Ukawa, Kenji Iwasaki, Tamotsu Higuchi, Koichiro Iwashita
  • Patent number: 5770166
    Abstract: The present invention relates to a slurry thickening tank comprising a tank body disposed below the surface of a slurry within a slurry tank, a slurry inlet provided in the upper part of the tank body, a thickened slurry outlet provided in the lower part of the tank body, and supernatant liquid withdrawal means provided in the upper part of the tank body, whereby the slurry introduced into the tank body through the slurry inlet is thickened by sedimentation in the tank body and the resulting thickened slurry is discharged from the tank body through the slurry outlet, wherein the surface of the structural member of the tank body extending from the slurry inlet to the thickened slurry outlet has an angle of inclination greater than the angle of repose for the thickened slurry, and to an absorption tower for use in flue gas desulfurization systems which is equipped with such a slurry thickening tank.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: June 23, 1998
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Taku Shimizu, Koichiro Iwashita, Yoshikazu Endo, Masakazu Onizuka, Toru Takashina
  • Patent number: 5653944
    Abstract: This invention is related to a slurry filtration device and the wet lime-gypsum flue-gas desulfurization system comprising a slurry filtration device for the separation (concentration) of gypsum. The slurry filtration device comprises tank that has a slurry supply pipe at its upper part and a filtrate-drain hole at its bottom, a layer of filter sand lying on its bottom, a slurry accumulator arranged on the layer of filter sand, and a vibrator set in said slurry accumulator for vibrating the slurry. The present invention not only improves the solid-liquid separability remarkably but also saves cost and space.
    Type: Grant
    Filed: January 17, 1996
    Date of Patent: August 5, 1997
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Taku Shimizu, Koichiro Iwashita, Yoshikazu Endo, Masakazu Onizuka, Toru Takashina
  • Patent number: 5605552
    Abstract: A wet type flue gas desulfurization apparatus in which desulfurization of flue gas is carried out through gas/liquid phase contact of flue gas with an absorbent slurry. More particularly, disclosed in a combined absorption tower comprising an absorbent slurry liquid tank, a thickening tank serving for concentration by settling of a reaction product slurry formed through the reaction of the absorbent and SO.sub.
    Type: Grant
    Filed: May 16, 1995
    Date of Patent: February 25, 1997
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Taku Shimizu, Tsuyoshi Ohishi, Koichiro Iwashita, Yoshikazu Endo