Patents by Inventor John S. Craven

John S. Craven 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: 5518633
    Abstract: Process for treating aqueous media containing metal ions having valences of +2 and higher and optionally acid comprising:(a) contacting the aqueous media, at a pH of about 1-5, with an effective amount of product recycled from step (b) to dissolve at least some metal carbonates, produce at least some CO.sub.2, convert at least some metal ions having a valence of at least +3 to metal hydroxide precipitates, and neutralize some acid, if present;(b) contacting the product of step (a), at a pH of about 4-8.5, with an effective amount of Na.sub.2 CO.sub.3 to convert at least some metal ions of +2 valence to metal carbonate precipitates and form at least some dissolved sodium salts;(c) recovering, from a portion of the product from step (b) that is not recycled, metal carbonates, metal hydroxides, and sodium salts.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: May 21, 1996
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Cary V. Brown, John S. Craven, Gregory A. Martz, James E. Merkle, Jr., William L. Vick, Melissa C. Wagner
  • Patent number: 5158688
    Abstract: A process for removing inorganic gels and dispersed, particulate incompressible solids from a highly acid aqueous slurry (e.g., pH of -2 to +3) and a soluble metallic chloride content (e.g., 3 to 50%) involving rapidly and intimately contacting the slurry with a cationic Mannich polyacrylamide of molecular 4-15 million until a desired amount of gel and particulate solids are flocculated. By slowly and gently mixing a floc of the desired size is formed which is then removed. The process is especially suited for treating slurries produced by water quenching the hot metal chlorides and blowover ore and coke from a TiO.sub.2 chlorinator after TiCl.sub.4 has been removed.
    Type: Grant
    Filed: March 19, 1990
    Date of Patent: October 27, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John S. Craven, Herbert Valdsaar
  • Patent number: 4254654
    Abstract: A sample fluid and a reference fluid are alternately applied to a fluid detector and an output signal is derived that is proportional to the difference between the response of the detector to the fluids.
    Type: Grant
    Filed: October 7, 1976
    Date of Patent: March 10, 1981
    Assignee: Hewlett-Packard Company
    Inventors: David E. Clouser, John S. Craven
  • Patent number: 4185490
    Abstract: A thermal conductivity detector in which sample gas and reference gas are made to alternately flow through a thermal conductive cell at a given switching frequency and in which the output signal is applied to a synchronous detector wherein it is mixed with a control wave that is in phase quadrature with the flow component of the output signal.
    Type: Grant
    Filed: October 6, 1978
    Date of Patent: January 29, 1980
    Assignee: Hewlett-Packard Company
    Inventors: David E. Clouser, John S. Craven
  • Patent number: 4170126
    Abstract: A thermal conductivity cell is provided that is made of cast wafers of ceramic material having a groove in one or both planar abutting surfaces. A filament is mounted in the groove by attachment to the ends of electrical conductors that extend through one of the wafers in sealed relationship. Passageways extend between points in the groove and an exterior surface of the cell. Gaskets are formed on the exterior surface around the openings where the passageways emerge. The gaskets are formed by silk screening and firing one or more layers of thick film conductor paste onto the surface of a layer of thick film conductor paste and at least one superimposed layer of gold and binder.
    Type: Grant
    Filed: March 13, 1978
    Date of Patent: October 9, 1979
    Assignee: Hewlett-Packard Company
    Inventor: John S. Craven