Patents Assigned to Midrex Corporation
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Patent number: 6187076Abstract: A fluidized bed reduction method in which powder raw material, including powder ore or partially pre-reduced powder ore, forms a fluidized bed with, and is sequentially reduced by reducing gas while being moved between a plurality of fluidized bed chambers; and to a fluidized bed reduction reactor which can be used in the same method. The movement of the powder ore between the fluidized bed chambers is carried out giving priority to relatively larger powder particles with the aim of improving the stability of the fluidized bed in the fluidized bed chambers. The adjustment of the reducing power of each fluidized bed chamber is made possible by introducing the reducing gas into the fluidized bed chambers in parallel, whereby an increase in the degree of reduction of the raw material can be realised.Type: GrantFiled: January 17, 1997Date of Patent: February 13, 2001Assignees: Kabushiki Kaisha Kobe Seiko Sho, Midrex CorporationInventors: Takayuki Sugahara, Ryoichi Hata, Shintaro Ano, Kenji Ohiraki, Gilbert Yould Whitten, Jr.
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Patent number: 4470581Abstract: Ores which include in combination iron oxide, cobalt oxide and nickel oxide are treated in a continuous shaft reduction furnace to selectively reduce nickel and cobalt to metallized form while leaving the iron oxide in the oxide form. Reacted top gas is recycled and mixed with partially combusted gasified fossil fuel in a combustion chamber to achieve the required concentration of reductants in the reducing gas. The cooling zone operates with a similar concentration of reductants in the cooling gas. Apparatus is also disclosed for carrying out the process.Type: GrantFiled: January 20, 1983Date of Patent: September 11, 1984Assignee: Midrex CorporationInventors: William A. Ahrendt, David C. Meissner, Charles W. Sanzenbacher, John C. Scarlett
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Patent number: 4462526Abstract: A briquet sheet from a briquetting machine is subjected to shearing forces to sever the longitudinal webs of the sheet and subsequently, to bending forces to fracture the remaining transverse webs. The separator apparatus includes a pair of shear rolls with alternate shear lands and smaller diameter idler rolls. The shear rolls are followed by a pair of lobed separator rolls.Type: GrantFiled: June 14, 1982Date of Patent: July 31, 1984Assignee: Midrex CorporationInventors: Kenneth R. Dumont, Jack R. Robinson
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Patent number: 4439233Abstract: A method of making high quality reducing gas for the direct reduction of iron wherein natural gas and steam are passed through a steam reformer to form a high temperature reducing gas, followed by mixing the high temperature reducing gas with spent top gas from a direct reduction shaft furnace, then passing the mixture through a stoichiometric reformer to form a high quality reducing gas for introduction to the shaft furnace.Type: GrantFiled: May 9, 1983Date of Patent: March 27, 1984Assignee: Midrex CorporationInventor: Dominic M. Faccone
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Patent number: 4381939Abstract: Ores which include in combination iron oxide, cobalt oxide and nickel oxide are treated in a continuous shaft reduction furnace to selectively reduce nickel and cobalt to metallized form while leaving the iron oxide in the oxide form. Reacted top gas is recycled and mixed with partially combusted gasified fossil fuel in a combustion chamber to achieve the required concentration of reductants in the reducing gas. The cooling zone operates with a similar concentration of reductants in the cooling gas. Apparatus is also disclosed for carrying out the process.Type: GrantFiled: January 29, 1981Date of Patent: May 3, 1983Assignee: Midrex CorporationInventors: William A. Ahrendt, David C. Meissner, Charles W. Sanzenbacher, John C. Scarlett
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Patent number: 4365789Abstract: A method and apparatus for the direct reduction of iron in a shaft furnace using gas from the gasification of solid fossil fuel, such as coal, in which the fuel gas is desulfurized and upgraded in the shaft furnace and direct reduction of iron oxide is carried out in the same furnace. Clean export fuel can be produced by this method along with direct reduced iron. The apparatus includes means for controlling the temperature of the process gas entering the furnace.Type: GrantFiled: October 5, 1981Date of Patent: December 28, 1982Assignee: Midrex CorporationInventors: John C. Scarlett, Charles W. Sanzenbacher
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Patent number: 4358310Abstract: A method and apparatus for the dry collection of metallized fines from a direct reduction furnace cooling zone in which cooling gas removed from the cooling zone passes through a dust collector and the removed dust is cooled in a fluidized bed, the fluidizing gas being recirculated through an indirect cooler. The process is continuous and the fines are collected at a sufficiently low temperature for easy handling. The apparatus includes a hot gas cyclone in the cooling gas withdrawal line connected to a fluidized bed cooler, a conduit for withdrawing fluidizing gas from the fluidized bed cooler passes through a second cyclone dust collector then through an indirect cooler and returns to the fluidized bed cooler. Cool fines are withdrawn from the fluidized bed cooler into a collector.Type: GrantFiled: February 18, 1981Date of Patent: November 9, 1982Assignee: Midrex CorporationInventors: Charles W. Sanzenbacher, David C. Meissner
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Patent number: 4351513Abstract: Apparatus for the direct reduction of iron oxide utilizing sulfur-containing gas such as coke oven gas for the process gas. Sulfur-containing gas is heated by indirect heat exchange and injected into the furnace above the reduction zone to transfer the sulfur to the hot burden. The apparatus includes an upper bustle zone for prereduction and sulfur transfer, a lower bustle zone for the final reduction of the burden to metallized iron, and means to recycle spent top gas through cooling zone as cooling gas.Type: GrantFiled: January 29, 1981Date of Patent: September 28, 1982Assignee: Midrex CorporationInventor: Charles W. Sanzenbacher
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Patent number: 4333761Abstract: A method for the direct reduction of iron oxide utilizing sulfur-containing gas such as coke oven gas for the process gas. Sulfur-containing gas is heated and injected into a shaft furnace above the reduction zone into a prereduction and sulfur transfer zone for transferring sufficient sulfur from the process gas to the burden, that the catalyst for reforming the spent top gas will not be poisoned.Type: GrantFiled: December 12, 1980Date of Patent: June 8, 1982Assignee: Midrex CorporationInventors: William A. Ahrendt, Donald Beggs
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Patent number: 4331470Abstract: A method and apparatus for the direct reduction of iron in a shaft furnace using gas from the gasification of solid fossil fuel, such as coal, in which the fuel gas is desulfurized and upgraded in the shaft furnace and direct reduction of iron oxide is carried out in the same furnace. Clean export fuel can be produced by this method along with direct reduced iron. The apparatus includes means for controlling the temperature of the process gas entering the furnace.Type: GrantFiled: September 15, 1980Date of Patent: May 25, 1982Assignee: Midrex CorporationInventors: John C. Scarlett, Charles W. Sanzenbacher
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Patent number: 4316739Abstract: A method and apparatus for producing molten iron in which pulverized coal is gasified with oxygen in an iron melting chamber, iron pellets on an upstanding hearth in the melting chamber are exposed to the gasification heat and melted. Molten iron trickles down from the hearth to a surrounding liquid bath. Off-gases from the chamber are utilized for direct reduction of iron oxide pellets to produce hot reduced iron pellets which are melted in the chamber.Type: GrantFiled: August 25, 1980Date of Patent: February 23, 1982Assignee: Midrex CorporationInventors: Donald Beggs, John C. Scarlett
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Patent number: 4306903Abstract: A method and apparatus for reducing particulate iron oxide to molten iron utilizing solid carbonaceous fuel as reductant in a shaft type reducing furnace, in which a furnace burden is formed of a mixture of iron oxide lumps or pellets and particulate solid fuel. Reacted top gas is upgraded and recirculated through the burden in counterflow relationship thereby heating and reducing the burden. The heat for reduction is generated by passing electric current through the burden. A portion of the heat for melting of reduced iron and a supplemental source of hot reducing gas is provided by oxy-fuel burners located in the shaft furnace above the molten iron pool.Type: GrantFiled: November 5, 1980Date of Patent: December 22, 1981Assignee: Midrex CorporationInventors: Donald Beggs, Bruce G. Kelly, David C. Meissner
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Patent number: 4286775Abstract: A method and apparatus for reducing particulate iron oxide and producing molten iron in which coal and oxygen are impinged onto a molten iron bath in a closed vessel to melt the iron and gasify the coal. The hot off gas from the vessel is removed and used as the reductant in a counterflow shaft furnace to reduce iron oxide pellets and/or iron ore in a continuous manner. The hot reduced product from the shaft is discharged directly into the molten iron bath and melted.Type: GrantFiled: September 19, 1980Date of Patent: September 1, 1981Assignee: Midrex CorporationInventors: John C. Scarlett, Charles W. Sanzenbacher
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Patent number: 4270740Abstract: Apparatus for reducing particulate iron oxide and producing molten iron in which coal and oxygen are injected into a molten iron bath to melt the iron, gasify the coal and produce a hot off-gas which is then used as the reductant in a counterflow shaft furnace to reduce iron oxide pellets and/or natural ore in a continuous manner. The hot reduced iron product from the shaft furnace is discharged directly into the molten iron bath from which the molten iron product is discharged.Type: GrantFiled: June 5, 1980Date of Patent: June 2, 1981Assignee: Midrex CorporationInventors: Charles W. Sanzenbacher, John C. Scarlett
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Patent number: 4270739Abstract: A method and apparatus for the direct reduction of iron oxide utilizing sulfur-containing gas such as coke oven gas for the process gas. Sulfur-containing gas is heated and injected above the reduction zone to transfer the sulfur to the hot burden. The apparatus includes an upper bustle zone for prereduction and sulfur transfer and a lower bustle zone for the final reduction of the burden to metallized iron.Type: GrantFiled: October 22, 1979Date of Patent: June 2, 1981Assignee: Midrex CorporationInventors: William A. Ahrendt, Donald Beggs
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Patent number: 4260412Abstract: A method of producing direct reduced iron with fluid bed coal gasification in which a portion of cooled, recycled gas is used as coolant in the gasification chamber and a second portion of the cleaned recycled gas is heated and mixed with the hot, dust-free gasification gas to form reducing gas for the direct reduction process. Limestone is preferably mixed with the pulverized coal feed to the gasification chamber to desulfurize the gas.Type: GrantFiled: January 16, 1980Date of Patent: April 7, 1981Assignee: Midrex CorporationInventors: Frank V. Summers, David C. Meissner, John C. Scarlett
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Patent number: 4251267Abstract: A method for the continuous direct reduction of metal oxides, ores, etc. to a hot metallized product in solid form. A unique gas seal is employed to prevent the leakage of reduction gas from the bottom of the closed shaft furnace when the product is being discharged which does not affect the discharge temperature of the product.Type: GrantFiled: August 24, 1979Date of Patent: February 17, 1981Assignee: Midrex CorporationInventors: Donald Beggs, Robert M. Escott
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Patent number: 4248626Abstract: A method and apparatus for reducing particulate iron oxide and producing molten iron in which coal and oxygen are impinged onto a molten iron bath in a closed vessel to melt the iron and gasify the coal. The hot off gas from the vessel is removed and used as the reductant in a counterflow shaft furnace to reduce iron oxide pellets and/or iron ore in a continuous manner. The hot reduced product from the shaft is discharged directly into the molten iron bath and melted.Type: GrantFiled: July 16, 1979Date of Patent: February 3, 1981Assignee: Midrex CorporationInventors: John C. Scarlett, Charles W. Sanzenbacher
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Patent number: 4248408Abstract: A method and apparatus for reducing particulate iron oxide to molten iron utilizing solid carbonaceous fuel as reductant in a shaft type reducing furnace, in which a furnace burden is formed of a mixture of iron oxide lumps or pellets and particulate solid fuel. Reacted top gas is upgraded and recirculated through the burden in counterflow relationship thereby heating and reducing the burden. The heat for reduction is generated by passing electric current through the burden. A portion of the heat for melting of reduced iron and a supplemental source of hot reducing gas is provided by oxy-fuel burners located in the shaft furnace above the molten iron pool.Type: GrantFiled: July 25, 1979Date of Patent: February 3, 1981Assignee: Midrex CorporationInventors: Donald Beggs, Bruce G. Kelley, David C. Meissner
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Patent number: 4238226Abstract: A method and apparatus for reducing particulate iron oxide and producing molten iron in which coal and oxygen are injected into a molten iron bath to melt the iron, gasify the coal and produce a hot off-gas which is then used as the reductant in a counterflow shaft furnace to reduce iron oxide pellets and/or natural ore in a continuous manner. The hot reduced iron product from the shaft furnace is discharged directly into the molten iron bath from which the molten iron product is discharged.Type: GrantFiled: July 16, 1979Date of Patent: December 9, 1980Assignee: Midrex CorporationInventors: Charles W. Sanzenbacher, John C. Scarlett