Patents by Inventor Donald A. Dahlstrom

Donald A. Dahlstrom 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: 5006349
    Abstract: A protein product is produced by a process that includes introducing a protein-containing fluid and a reactant stream containing a component reactive with the protein, such as an acid through a resonating chamber. The protein-containing fluid and acid are introduced into the chamber at a velocity and pressure which causes instantaneous mixing of the protein-containing fluid with the acid to form an acidified mixture. The acid is introduced into the chamber in a ratio such that the pH of the protein-containing fluid is lowered past the isoelectric point of the protein.
    Type: Grant
    Filed: June 17, 1988
    Date of Patent: April 9, 1991
    Assignee: Land O'Lakes, Inc.
    Inventors: Donald Dahlstrom, Stephen Dybing, Barney J. Gaffney
  • Patent number: 4342638
    Abstract: An apparatus arrangement and method of operation for treatment of the residue from a coal liquifaction and hydrogenation reactor, which residue contains 5% to 10% solids and is at elevated temperature (f.i. above 700.degree. F.) and pressure of 150-200 psi. Said apparatus comprising a continuous pressure precoat filter sealed against pressure loss, a sealed repulper associated with said pressure filter for repulping filter cake in relatively cooler solvent while maintaining the pressure thereon at about 150-200 lbs/in..sup.2 to yield a slurry, then utilizing the pressure to force the slurry into and through a second pressure filter wherein to effect liquid solids separation; and separately discharging the filtrate and cake from the second filter.
    Type: Grant
    Filed: December 30, 1980
    Date of Patent: August 3, 1982
    Assignee: Envirotech Corporation
    Inventor: Donald A. Dahlstrom
  • Patent number: 4147756
    Abstract: In a cooperative combination of two scrubbing systems, the first scrubbing system operates upon combustion gases with an aqueous solution to remove hydrogen chloride gas and other chlorine components. The second scrubbing system subsequently operates upon the combustion gases with a sodium-base solution to absorb sulfur oxides. The products of the two scrubbing systems are treated in combination to form a material for disposal and to generate the aqueous scrubbing solution for the chloride scrubbing system.
    Type: Grant
    Filed: April 9, 1976
    Date of Patent: April 3, 1979
    Assignee: Envirotech Corporation
    Inventors: Donald A. Dahlstrom, William Ellison, James H. Wilhelm
  • Patent number: 3989464
    Abstract: Sulfur dioxide is scrubbed from stack gases in an absorption device by a sodium-based aqueous scrubbing solution, a portion of which is subsequently and continuously regenerated outside the absorption apparatus by a causticizing reaction with slaked lime. The causticized solution is routed through a settling device wherefrom a portion of the aqueous sediment is returned to the causticizing zone to provide seed crystals which encourage the formation of larger sized solid particles; also, a portion of the aqueous sediment from the settling device is continuously mechanically dewatered and then removed from the system. The liquid effluent solution from the settling device is passed to a solids-contacting and reaction device for mixing with sodium carbonate in order to reduce the calcium ion concentration and the solids content of the solution. The underflow of the solids-contacting device is conveyed back to the causticizing zone and the clarified overflow, i.e.
    Type: Grant
    Filed: February 24, 1975
    Date of Patent: November 2, 1976
    Assignee: Envirotech Corporation
    Inventors: Donald A. Dahlstrom, Conrad F. Cornell