Patents by Inventor Glenn E. Hoffman

Glenn E. Hoffman 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).

  • Publication number: 20010054329
    Abstract: This invention relates to a method for operation of a moving hearth furnace in conjunction with an electric melter for production of high purity iron product having a range of silicon and manganese, with low sulfur and phosphorus content. The method includes producing high purity iron product and a range of carbon content product from iron oxide and carbon bearing agglomerates, including the steps of providing a furnace for direct reduction of iron oxide and carbon bearing agglomerates, pre-reducing iron and carbon bearing agglomerates in a furnace having a moving hearth surface, producing intermediate carbon-containing metallized iron. An electric melter furnace is utilized for receiving intermediate carbon-containing metallized iron from the pre-reducing step, which is fed directly and continuously into a central interior area of the electric melter, with heating of the carbon-containing metallized iron in the electric melter under elevated temperatures of about 1300° C. to about 1700° C.
    Type: Application
    Filed: June 25, 2001
    Publication date: December 27, 2001
    Inventors: Glenn E. Hoffman, Ronald D. Gray
  • Publication number: 20010052273
    Abstract: The present invention is an apparatus and method for the direct reduction of iron oxide utilizing a rotary hearth furnace to form a high purity carbon-containing iron metal button. The hearth layer may be a refractory or a vitreous hearth layer of iron oxide, carbon, and silica compounds. Additionally, coating materials may be introduced onto the refractory or vitreous hearth layer before iron oxide ore and carbon materials are added, with the coating materials preventing attack of the molten iron on the hearth layer. The coating materials may include compounds of carbon, iron oxide, silicon oxide, magnesium oxide, and/or aluminum oxide. The coating materials may be placed as a solid or a slurry on the hearth layer and heated, which provides a protective layer onto which the iron oxide ores and carbon materials are placed. The iron oxide is reduced and forms molten globules of high purity iron and residual carbon, which remain separate from the hearth layer.
    Type: Application
    Filed: March 12, 1999
    Publication date: December 20, 2001
    Inventors: DAVID C. MEISSNER, GLENN E. HOFFMAN, KYLE J. SHOOP, TAKUYA NEGAMI, AKIRA URAGAMI, YASHUHIRO TANIGAKI, SHUZO ITO, ISAO KOBAYASHI, OSAMU TSUGE, KOJI TOKUDA, SHOICHI KIKUCHI
  • Publication number: 20010047699
    Abstract: The invention is a method of making metallized iron agglomerates by combining iron/steel particles and a reductant material with a cellulose fiber binder material, compacting the combination to form a solid agglomerate, and reducing the iron portions of the agglomerate in a direct reduction furnace. The cellulose fiber binder material provides an agglomerate having improved strength and lower overall cost than comparable agglomerates using binders known in the art.
    Type: Application
    Filed: May 10, 2001
    Publication date: December 6, 2001
    Inventors: Glenn E. Hoffman, James M. McClelland
  • Patent number: 6251156
    Abstract: This invention relates to a method for operation of a rotary hearth furnace in conjunction with an electric melter for production of high purity iron product having a range of silicon and manganese, with low sulfur and phosphorus content. The method includes producing high purity iron product and a range of carbon content product from iron oxide and carbon bearing compacts, including the steps of providing a furnace for direct reduction of iron oxide and carbon bearing compacts, pre-reducing iron and carbon bearing compacts in a furnace having a rotary hearth surface, producing intermediate carbon-containing metallized iron. An electric melter furnace is utilized for receiving intermediate carbon-containing metallized iron from the pre-reducing step, which is fed directly and continuously into a central interior area of the electric melter, with heating of the carbon-containing metallized iron in the electric melter under elevated temperatures of about 1300° C. to about 1700° C.
    Type: Grant
    Filed: October 29, 1999
    Date of Patent: June 26, 2001
    Assignee: Midrex Technologies, Inc.
    Inventors: Glenn E. Hoffman, Ronald D. Gray
  • Patent number: 6214087
    Abstract: A method for producing solid metal product is disclosed including the steps of providing carbon and metal bearing compounds in compacts, coating the compacts with treatment materials, encapsulating the compacts with carbonaceous containing materials to form a residual layer, and treating the residual layer before introduction of the compacts into a furnace. The compacts contain carbon containing metal bearing compounds, and are coated with mixtures of carbonaceous materials dispersed within a binder material such as a viscous liquid, molasses, alcohol, or fuel oil. The coated compacts are treated to form a hardened outer residual layer. The outer residual layer provides for a sacrificial outer coating on the compacts that reacts with any oxidizing gaseous components within the furnace, while the carbon containing metal bearing compounds within the compacts are heated and metallized inside the compounds.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: April 10, 2001
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: Glenn E. Hoffman, David C. Meissner, Kyle J. Shoop
  • Patent number: 4731112
    Abstract: A method of making a molten ferroalloy product in a melting furnace by charging a briquet consisting essentially of metallized iron, granulated alloy metal oxide, and a carbon source, such as coke breeze, to the melting furnace, burning solid carbonaceous material to reduce the alloy metal oxide to metallized form and to heat the charge to form a molten ferroalloy product. Fluxes and slag formers are also charged to the furnace as required.
    Type: Grant
    Filed: June 17, 1986
    Date of Patent: March 15, 1988
    Assignee: Midrex International, B.V. Rotterdam, Zurich Branch
    Inventor: Glenn E. Hoffman
  • Patent number: 4728358
    Abstract: A briquet consists essentially of metallized iron fines, formed by direct reduction of iron oxide, granulated or fine silica, a carbon source such as coke breeze, and less than 3.5 percent of other components, or impurities. The briquet product has a density of from 2.0 to 6.0 g/cc, and is particularly well suited for steelmaking operations.The method for making the briquet is also disclosed.
    Type: Grant
    Filed: April 30, 1986
    Date of Patent: March 1, 1988
    Assignee: Midrex International, B.V. Rotterdam, Zurich Branch
    Inventors: Glenn E. Hoffman, Bradford G. True
  • Patent number: 4685964
    Abstract: A highly efficient method and apparatus for production of molten iron using coal by coal gasification in a molten iron gasifier-melter. The gasifier-melter is coupled to a direct reduction shaft furnace and utilizes both the gaseous and solid output of the shaft furnace. The process is especially efficient when using non-metallurgical coals.
    Type: Grant
    Filed: October 3, 1985
    Date of Patent: August 11, 1987
    Assignee: Midrex International B.V. Rotterdam
    Inventors: Frank V. Summers, John C. Scarlett, David C. Meissner, Glenn E. Hoffman