Patents Assigned to Minnesota Power and Light
  • Patent number: 5354345
    Abstract: A process for thermochemical beneficiation of carbonaceous solids including a fraction of particles of a size less than 1/4 inch across is provided. The process includes steps of providing a reactor vessel including therein a retaining structure operably positioned to separate a portion of carbonaceous solids from a wall of the reactor vessel, with a free standing liquids region therebetween. The process includes providing a portion of carbonaceous solids piled above an uppermost liquid level of process liquid within the reactor vessel. The disclosure also provides a preferred reactor arrangement for conduct of the process.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: October 11, 1994
    Assignee: Minnesota Power and Light
    Inventor: George R. Nehls, Jr.
  • Patent number: 4765828
    Abstract: A method of reducing metal oxides comprises introducing feedstock material into a plasma torch reactor according to two different flow patterns. A primary feedstock is fed into the immediate vicinity of the plasma stream in a helical pattern surrounding the plasma stream. The primary feedstock material preferably comprises the metal oxides to be reduced within the reactor. A secondary feedstock material is fed at a more remote location, preferably in a flow pattern developing a protective wall for the inside of the reactor. A preferred assembly is provided for application of the process. For the preferred embodiment, the assembly comprises a top plate, a central ramp, a bottom plate and a liner to form separate feed channels for the primary and secondary feedstock.
    Type: Grant
    Filed: June 19, 1987
    Date of Patent: August 23, 1988
    Assignee: Minnesota Power & Light Company
    Inventors: George R. Nehls, Jr., Scott D. Anderson