Patents by Inventor Andrew Nicolson Carruthers

Andrew Nicolson Carruthers 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 drying liquid-borne solid material
    Patent number: 5946818
    Abstract: A method and apparatus are disclosed for continuously drying, preferably with agglomeration and/or coating and sizing, and separating a solid product from a liquid feed material, especially bauxite slurry which passes through a very sticky phase during drying, without significant encrustation of the equipment used.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: September 7, 1999
    Assignee: Alcan International Limited
    Inventors: Hamish Baxter, Andrew Nicolson Carruthers, Hans-Peter Elkjaer, Bryan Hiscox, Jens Fenger, Benny E. Raahauge, Jose Gil Fernandez Pulpeiro
  • Production of alumina
    Patent number: 4038039
    Abstract: In order to control the sodium oxalate level in the liquor employed in the Bayer process for the production of alumina, a part of the spent liquor recovered from alumina trihydrate precipitation stage is concentrated by evaporation to render it supersaturated with respect to sodium oxalate. The thus concentrated liquor is then sprayed onto a packing in an enclosed space under conditions such that the supersaturation of the droplets at impact on the packing exceeds a critical supersaturation. The sprayed liquor deposits sodium oxalate on the packing and is recovered for recirculation to the process circuit.
    Type: Grant
    Filed: July 6, 1976
    Date of Patent: July 26, 1977
    Assignee: Alcan Research and Development Limited
    Inventors: Andrew Nicolson Carruthers, John Edward Deutschman, Michael George Willis