Patents by Inventor Dale L. Letcher

Dale L. Letcher 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: 8029650
    Abstract: A method for purifying used antifreeze is disclosed. An antifreeze recycling systems uses a simple-distillation apparatus adapted to distill clean antifreeze from used antifreeze. A novel scraper blade is used in the simple-distillation apparatus. Also, antifreeze recycling methods that minimize waste and generate nontoxic, landfillable waste are provided. An antifreeze product produced by the present method, and a nontoxic, landfillable sludge product produced by the present method, are disclosed.
    Type: Grant
    Filed: September 26, 2007
    Date of Patent: October 4, 2011
    Inventor: Dale L. Letcher