Patents by Inventor Pierre Ledent

Pierre Ledent 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).

  • Controlled retracting gasifying agent injection point process for UCG sites
    Patent number: 4754811
    Abstract: New controlled retracting gasifying agent injection point process for UCG sites.The process consists of a retraction of the gasifying agent injection point achieved by gradually plugging the tubing ends either by pneumatic injection of inert granulated material with a thermosetting binder, or by closing valves set at regular intervals inside the tubings.
    Type: Grant
    Filed: August 24, 1987
    Date of Patent: July 5, 1988
    Assignee: Institution pour le Developpement de la Gazeification Souterraine
    Inventors: Pierre Ledent, Claus Sonntag
  • Controlled retracting gasifying agent injection point process for UCG sites
    Patent number: 4705109
    Abstract: The process consists of a retraction of the gasifying agent injection point achieved by gradually plugging the tubing ends either by pneumatic injection of inert granulated material with a thermosetting binder, or by closing valves set at regular intervals inside the tubings.
    Type: Grant
    Filed: February 27, 1986
    Date of Patent: November 10, 1987
    Assignee: Institution pour le Developpement de la Gazeification Souterraine
    Inventors: Pierre Ledent, Claus Sonntag
  • Thermal-operated valve for control of coolant rate of flow in oil wells
    Patent number: 4209065
    Abstract: A thermally operated valve for automatic control of the rate of flow of a fluid coolant for hot gases produced by underground gasification of solid fuel deposits or by in situ combustion in oil wells, incorporating a temperature-sensitive element comprising a metal tube several meters long to be incorporated in a pipe for supplying coolant to the well, and a rod of a metal having a low coefficient of expansion coaxial with the pipe, the upper end of which rod is attached to the upper part of the metal tube and the lower end of which rod is flexibly connected to a valve member by a connecting element having adjustable clearance or play.
    Type: Grant
    Filed: November 13, 1978
    Date of Patent: June 24, 1980
    Assignee: Institut National des Industries Extractives
    Inventor: Pierre Ledent