Patents by Inventor Yoshitaka Sawa

Yoshitaka Sawa 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: 7473393
    Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: January 6, 2009
    Assignee: JFE Steel Corporation
    Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
  • Publication number: 20070051203
    Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.
    Type: Application
    Filed: November 7, 2006
    Publication date: March 8, 2007
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
  • Patent number: 7141205
    Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: November 28, 2006
    Assignee: JFE Steel Corporation
    Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
  • Publication number: 20050103160
    Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.
    Type: Application
    Filed: December 22, 2004
    Publication date: May 19, 2005
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
  • Patent number: 6872074
    Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.
    Type: Grant
    Filed: May 4, 2004
    Date of Patent: March 29, 2005
    Assignee: JFE Steel Corporation
    Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
  • Publication number: 20040202979
    Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.
    Type: Application
    Filed: May 4, 2004
    Publication date: October 14, 2004
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
  • Patent number: 6629839
    Abstract: The invention provides a method and apparatus for charging a raw material and a carbonaceous material, in which a reduced product generated on a hearth can be quickly melted for reliable separation into a metal and slag, and the metal and the slag can be easily discharged out of a furnace as individual small agglomerates. With the charging method and apparatus, when charging the raw material and the carbonaceous material onto the moving hearth of the moving hearth furnace, the carbonaceous material is first charged onto the moving hearth to form a carbonaceous material layer thereon. The raw material or a mixture of the raw material and a carbonaceous material is then charged onto the carbonaceous material layer to form a raw material layer thereon. A projection is then pressed against the raw material layer from above, thereby forming a plurality of recesses in the surface of the carbonaceous material layer.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: October 7, 2003
    Assignee: Kawasaki Steel Corporation
    Inventors: Tatsuya Ozawa, Tetsuya Yamamoto, Yoshitaka Sawa
  • Publication number: 20020053307
    Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.
    Type: Application
    Filed: October 24, 2001
    Publication date: May 9, 2002
    Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
  • Publication number: 20020022208
    Abstract: The invention provides a method and apparatus for charging a raw material and a carbonaceous material, in which a reduced product generated on a hearth can be quickly melted for reliable separation into a metal and slag, and the metal and the slag can be easily discharged out of a furnace as individual small agglomerates. With the charging method and apparatus, when charging the raw material and the carbonaceous material onto the moving hearth of the moving hearth furnace, the carbonaceous material is first charged onto the moving hearth to form a carbonaceous material layer thereon. The raw material or a mixture of the raw material and a carbonaceous material is then charged onto the carbonaceous material layer to form a raw material layer thereon. A projection is then pressed against the raw material layer from above, thereby forming a plurality of recesses in the surface of the carbonaceous material layer.
    Type: Application
    Filed: July 27, 2001
    Publication date: February 21, 2002
    Applicant: Kawasaki Steel Corporation
    Inventors: Tatsuya Ozawa, Tetsuya Yamamoto, Yoshitaka Sawa
  • Patent number: 6270552
    Abstract: Traveling hearth furnace and an operating method thereof, which, when stacking a layer consisting of a mixture of oxides such as fine iron ore and a fine solid reducing material onto a horizontally traveling hearth and reducing the oxides through radiant heat transfer from above the hearth, is based on melting the reduction product in the course of up to a discharge port, and causing aggregation and separation of slag in from the reduction product, followed by solidifying the reducible material.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: August 7, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Kanji Takeda, Yoshitaka Sawa, Tetsuya Yamamoto, Tetsuya Kikui
  • Patent number: 6264721
    Abstract: A mixed layer of fine ore and coal char and a layer of fine coal are stacked on a hearth in the form of separate layers from each other. The fine ore is reduced while fine coal is pyrolyzed to produce coal char. The produced coal char is used repeatedly.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: July 24, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Kanji Takeda, Yoshitaka Sawa, Tetsuya Yamamoto
  • Patent number: 6248152
    Abstract: With a solid fine reducing material containing hydrogen placed as a lower layer on a movable hearth, a powdered mixture of an oxide powder dominantly of a fine iron ore and a solid fine reducing material is stacked in layered arrangement, and subsequent reduction operation is performed.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: June 19, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Kanji Takeda, Yoshitaka Sawa
  • Patent number: 6224820
    Abstract: A traveling hearth for producing reduced metal by charging and stacking a raw material containing a metal-containing material and a solid-reducing material on a horizontally moving hearth, arranged for disposing a solid-reducing material layer on the hearth, forming concave portions at the solid-reducing material surface, stacking the raw material on the surface of the solid-reducing material layer, reducing the raw material by at least once heating and melting the material on the hearth to separate metal and gangue and ash ingredients, and discharging metal from the hearth.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: May 1, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Hiroshi Itaya
  • Patent number: 6135766
    Abstract: A feed stock composed of an iron ore and a solid reducing material is supplied in a movable hearth furnace provided with a unidirectionally movable hearth, stacked on the movable hearth and then subjected to a series of operations of preheating, reduction and discharge. To this end, a feed stock subsequently supplied in such furnace is preheated by utilizing a heat applied by the finished reduced ore and is stacked on the movable hearth.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: October 24, 2000
    Assignee: Kawasaki Steel Corporation
    Inventors: Kanji Takeda, Yoshitaka Sawa
  • Patent number: 6126718
    Abstract: Producing reduced metal by charging and stacking a raw material containing a metal-containing material and a solid reducing material on a horizontally moving hearth of a traveling hearth furnace, by disposing a solid reducing material layer on the hearth, forming concave portions at the solid reducing material surface, stacking the raw material on the surface of the solid reducing material layer, reducing raw material by at least once heating and melting the material on the hearth to separate metal and gangue and ash ingredients, and discharging metal from the hearth.
    Type: Grant
    Filed: March 29, 1999
    Date of Patent: October 3, 2000
    Assignee: Kawasaki Steel Corporation
    Inventors: Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Hiroshi Itaya
  • Patent number: 5839495
    Abstract: A roll outer layer material for hot rolling includes, as analyzed in weight percent, of 2.5-4.0% C, 6.0-20% Cr, 3.0-10.0% V, 0.6-5.0% Nb, 2.0-15% Mo, 3.0% or below Si, 3.0% or below Mn, C, V, Nb and Cr satisfying a following formula (1),10.5(%).ltoreq.6.5.C(%)-1.3.V(%)-0.7.Nb(%).ltoreq.2.Cr(%)-2(%)(1), and the balance being Fe and incidental impurities. A method of manufacturing a roll for hot rolling includes the steps of centrifugally casting an outer layer material having the above composition, centrifugally casting graphite steel containing 0.5% or above of C as an intermediate layer, and casting an axis material which is a spheroidal graphite cast iron, a flake graphite cast iron or a graphite steel. C is present in the intermediate layer in an amount which satisfies a following formula (2),C (intermediate layer).gtoreq.2.0-0.5 (C-0.2 V-0.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: November 24, 1998
    Assignee: Kawasaki Steel Corporation
    Inventors: Kenji Ichino, Tomoya Koseki, Yoshitaka Sawa
  • Patent number: 5738734
    Abstract: A centrifugal cast roll shell material composed of a granular MC carbide, graphite and C: 2.5 to 4.7%, Si: 0.8 to 3.2%, Mn: 0.1 to 2.0%, Cr: 0.4 to 1.9%, Mo: 0.6 to 5%, V: 3.0 to 10.0% and Nb: 0.6 to 7.0%, satisfying the following formulae (1), (2), (3) and (4):2.0+0.715 V+0.10 Nb.ltoreq.C (%) (1)1.1.ltoreq.Mo/Cr (2)Nb/V.ltoreq.0.8 (3)0.2.ltoreq.Nb/V (4),the remainder being Fe and inevitable impurities, wherein the pouring temperature is 1,400.degree. C. or higher.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: April 14, 1998
    Assignee: Kawasaki Steel Corporation
    Inventors: Yoshitaka Sawa, Tomoya Koseki, Kenji Ichino
  • Patent number: 5674171
    Abstract: A roll outer layer material for hot rolling consists essentially, as analyzed in weight percent, of 2.5-4.0% C, 6.0-20% Cr, 3.0-10.0% V, 0.6-5.0% Nb, 2.0-15% Mo, 3.0% or below Si, 3.0% or below Mn, C, V, Nb and Cr satisfying a formula where 10.5.ltoreq.6.5.C(%)--1.3.V(%)--0.7.Nb(%).ltoreq.2.Cr(%)--2, and the balance being Fe and incidental impurities. A method of manufacturing a roll for hot rolling comprises the steps of centrifugally casting an outer layer material having the above composition, centrifugally casting graphite steel containing 0.5% or above of C as an intermediate layer, and casting an axis material which is a spheroidal graphite cast iron, a flake graphite cast iron or a graphite steel. Carbon is present in the intermediate layer in an amount which satisfies a formula, C (intermediate layer).gtoreq.2.0-0.5?C(%)--0.2.V(%)--0.11.Nb(%)! (outer layer).
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: October 7, 1997
    Assignee: Kawasaki Steel Corporation
    Inventors: Kenji Ichino, Tomoya Koseki, Yoshitaka Sawa