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).
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Patent number: 7473393Abstract: 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: GrantFiled: November 7, 2006Date of Patent: January 6, 2009Assignee: JFE Steel CorporationInventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
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Publication number: 20070051203Abstract: 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: ApplicationFiled: November 7, 2006Publication date: March 8, 2007Applicant: JFE Steel Corporation, a corporation of JapanInventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
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Patent number: 7141205Abstract: 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: GrantFiled: December 22, 2004Date of Patent: November 28, 2006Assignee: JFE Steel CorporationInventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
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Publication number: 20050103160Abstract: 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: ApplicationFiled: December 22, 2004Publication date: May 19, 2005Applicant: JFE Steel Corporation, a corporation of JapanInventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
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Patent number: 6872074Abstract: 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: GrantFiled: May 4, 2004Date of Patent: March 29, 2005Assignee: JFE Steel CorporationInventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
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Publication number: 20040202979Abstract: 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: ApplicationFiled: May 4, 2004Publication date: October 14, 2004Applicant: JFE Steel Corporation, a corporation of JapanInventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
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Patent number: 6629839Abstract: 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: GrantFiled: July 27, 2001Date of Patent: October 7, 2003Assignee: Kawasaki Steel CorporationInventors: Tatsuya Ozawa, Tetsuya Yamamoto, Yoshitaka Sawa
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Publication number: 20020053307Abstract: 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: ApplicationFiled: October 24, 2001Publication date: May 9, 2002Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
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Publication number: 20020022208Abstract: 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: ApplicationFiled: July 27, 2001Publication date: February 21, 2002Applicant: Kawasaki Steel CorporationInventors: Tatsuya Ozawa, Tetsuya Yamamoto, Yoshitaka Sawa
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Patent number: 6270552Abstract: 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: GrantFiled: May 26, 1999Date of Patent: August 7, 2001Assignee: Kawasaki Steel CorporationInventors: Kanji Takeda, Yoshitaka Sawa, Tetsuya Yamamoto, Tetsuya Kikui
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Patent number: 6264721Abstract: 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: GrantFiled: May 26, 1999Date of Patent: July 24, 2001Assignee: Kawasaki Steel CorporationInventors: Kanji Takeda, Yoshitaka Sawa, Tetsuya Yamamoto
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Patent number: 6248152Abstract: 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: GrantFiled: May 27, 1999Date of Patent: June 19, 2001Assignee: Kawasaki Steel CorporationInventors: Kanji Takeda, Yoshitaka Sawa
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Patent number: 6224820Abstract: 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: GrantFiled: October 5, 1999Date of Patent: May 1, 2001Assignee: Kawasaki Steel CorporationInventors: Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Hiroshi Itaya
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Patent number: 6135766Abstract: 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: GrantFiled: May 27, 1999Date of Patent: October 24, 2000Assignee: Kawasaki Steel CorporationInventors: Kanji Takeda, Yoshitaka Sawa
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Patent number: 6126718Abstract: 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: GrantFiled: March 29, 1999Date of Patent: October 3, 2000Assignee: Kawasaki Steel CorporationInventors: Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Hiroshi Itaya
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Patent number: 5839495Abstract: 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: GrantFiled: September 18, 1997Date of Patent: November 24, 1998Assignee: Kawasaki Steel CorporationInventors: Kenji Ichino, Tomoya Koseki, Yoshitaka Sawa
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Patent number: 5738734Abstract: 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: GrantFiled: October 29, 1996Date of Patent: April 14, 1998Assignee: Kawasaki Steel CorporationInventors: Yoshitaka Sawa, Tomoya Koseki, Kenji Ichino
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Patent number: 5674171Abstract: 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: GrantFiled: June 26, 1995Date of Patent: October 7, 1997Assignee: Kawasaki Steel CorporationInventors: Kenji Ichino, Tomoya Koseki, Yoshitaka Sawa