Patents by Inventor Aaron T. Leavitt

Aaron T. Leavitt 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).

  • Feeding comminuted fibrous material using high pressure screw and centrifugal pumps
    Patent number: 6841042
    Abstract: A system and method for feeding comminuted cellulosic fibrous material such as wood chips to the top of a treatment vessel such as a continuous digester provide enhanced simplicity, operability, and maintainability by eliminating the high pressure transfer device conventionally used in the prior art. Instead of a high pressure transfer device the steamed and slurried chips are pressurized using a single vane slurry pump in series with a centrifugal slurry pump both of which are located at least thirty feet below the top of the treatment vessel and for pressurizing the slurry to a pressure of at least about 10 bar gauge.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: January 11, 2005
    Assignee: Andritz, Inc.
    Inventors: C. Bertil Stromberg, Aaron T. Leavitt, J. Robert Prough
  • Feeding comminuted fibrous material using high pressure screw and centrifugal pumps
    Publication number: 20030173047
    Abstract: A system and method for feeding comminuted cellulosic fibrous material such as wood chips to the top of a treatment vessel such as a continuous digester provide enhanced simplicity, operability, and maintainability by eliminating the high pressure transfer device conventionally used in the prior art. Instead of a high pressure transfer device the steamed and slurried chips are pressurized using a single vane slurry pump in series with a centrifugal slurry pump both of which are located at least thirty feet below the top of the treatment vessel and for pressurizing the slurry to a pressure of at least about 10 bar gauge.
    Type: Application
    Filed: January 30, 2003
    Publication date: September 18, 2003
    Applicant: Andritz, Inc.
    Inventors: C. Bertil Stromberg, Aaron T. Leavitt, J. Robert Prough
  • Pressure vessel for a pulp mill having overflow chute
    Publication number: 20020185176
    Abstract: Disclosed is a pressure vessel comprising a pressurized chamber; an overflow chute having an inlet open to an upper level of the chamber, a chute passage extending from the upper level to a lower level, and a chute discharge; wherein the chute passage has a bend to defect a flow in the chute passage before the flow exits the discharge.
    Type: Application
    Filed: May 1, 2002
    Publication date: December 12, 2002
    Inventors: Aaron T. Leavitt, David J. Lebel, Patrick J. Pepin, Helena C. Aguiar, C. Bertil Stromberg, Michael Rutter, Patrick J. Sullivan, Keith W. Flint, James F. Archambault, Leslie A. Rathbun