Patents by Inventor Robert J. Steffen

Robert J. Steffen 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 and apparatus for treatment of excavated landfill material in a plasma fired cupola
    Patent number: 4998486
    Abstract: Excavatged landfill material is treated in a plasma fired cupola in a process wherein hazardous material such as PCB's are volatilized and consumed in an afterburner above the cupola and hazardous materials containing heavy metals are fixed in vitreous material made molten within the cupola and resulting in a non-leachable solid product.
    Type: Grant
    Filed: April 27, 1989
    Date of Patent: March 12, 1991
    Assignee: Westinghouse Electric Corp.
    Inventors: Shyam V. Dighe, Raymond F. Taylor, Jr., Robert J. Steffen, David M. Rohaus