Patents by Inventor Thomas D. Sandbrook

Thomas D. Sandbrook 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).

  • Synthesis of hexafluoropropylene
    Patent number: 6924403
    Abstract: The present invention relates to the process of pyrolyzing tetrafluoroethylene to hexafluoropropylene by carrying out the pyrolysis in a tubular reactor that is lined with either nickel or nickel alloy which contains no greater than 8 wt % chromium.
    Type: Grant
    Filed: May 7, 2003
    Date of Patent: August 2, 2005
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: John James Barnes, Kenneth Paul Kelch, Thomas D. Sandbrook, David John Van Bramer
  • Synthesis of hexafluoropropylene
    Publication number: 20040002621
    Abstract: The present invention relates to the process of pyrolyzing tetrafluoroethylene to hexafluoropropylene by carrying out the pyrolysis in a tubular reactor that is lined with either nickel or nickel alloy which contains no greater than 8 wt % chromium.
    Type: Application
    Filed: May 7, 2003
    Publication date: January 1, 2004
    Inventors: John James Barnes, Kenneth Paul Kelch, Thomas D. Sandbrook, David John Van Bramer
  • Method and apparatus for controlling a flotation cell
    Patent number: 4797559
    Abstract: A method and apparatus for determining the reflectivity of the tailings from a coal flotation cell to optimize the cell operation. A photoelectric detector determines the coal content of the tailings and through a process controller; frother and collector addition to the cell is monitored. An ultrasonic energy vibration is periodically transmitted to the detector to remove deposits on the detector to optimize detector operation.
    Type: Grant
    Filed: November 6, 1987
    Date of Patent: January 10, 1989
    Assignee: Consolidation Coal Company
    Inventors: Hayward B. Oblad, Michael G. Nelson, Thomas D. Sandbrook
  • Control of froth cell performance through the use of differential bubbler tubes
    Patent number: 4552651
    Abstract: A method of controlling the separation of coal from a mixture of coal and refuse in a froth flotation device by measuring the differential back pressure between two gas bubbler tubes immersed to different depths into the body of pulp in the device to produce a first control signal representative of the pulp density, and adjusting the rate of addition of a froth enhancement additive to the froth flotation device responsive to changes in said first signal; a second signal, produced by measuring back pressure of a single bubbler tube and representative of the pulp level in said device, can be corrected for changes in density by combining it with said first signal and then utilized to control liquid level in the cell by adjusting the rate of withdrawal of refuse therefrom.
    Type: Grant
    Filed: February 1, 1984
    Date of Patent: November 12, 1985
    Assignee: Conoco Inc.
    Inventors: Thomas D. Sandbrook, Roy O. Scandrol