Patents by Inventor Lloyd D. Stewart, Jr.

Lloyd D. Stewart, Jr. 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).

  • Process for in situ decontamination of subsurface soil and groundwater
    Patent number: 5018576
    Abstract: A method is provided for in situ decontamination of contaminated subsurface area by injection of steam into injection wells and withdrawing liquids and vapors from extraction wells under subatmospheric pressure whereby steam is passed through the contaminated area in an essentially horizontal direction. After a substantial portion of the contamination has been removed in this manner, the injection of steam is ceased, but the extraction at subatmospheric pressure is continued, to volatilize and remove the residual water and contaminants trapped in the pores of the soil. The steam injection may be periodically resumed to reheat the area and to replenish the water in the pores.
    Type: Grant
    Filed: August 16, 1989
    Date of Patent: May 28, 1991
    Assignee: The Regents of the University of California
    Inventors: Kent S. Udell, Nicholas Sitar, James R. Hunt, Lloyd D. Stewart, Jr.