Patents by Inventor Anton Hruschka

Anton Hruschka 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).

  • Chlorine-free bleaching method for dissolving-grade pulps using an OP-Z-P sequence
    Patent number: 5145557
    Abstract: A three-stage bleaching process for dissolving grade pulp utilizes the sequence OP(alkaline)-Z-P and the off gas from the Z-stage is delivered to the alkaline (OP)-stage whose parameters are controlled to fully react all of the oxygen of the off gas. The filtrate or waste water from the Z-stage, at a pH below 3, serves to dilute the alkaline OP-stage pulp before Z-stage bleaching and/or for de-ashing of the P pulp following the P-stage.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: September 8, 1992
    Assignee: Lenzing Aktiengesellschaft
    Inventors: Walter Peter, Anton Hruschka, Oskar Hoglinger
  • Method for delignification of cellulose with oxygen
    Patent number: 4834837
    Abstract: Method and apparatus for delignifying chemical pulp by means of oxygen, in which an aqueous slurry of chemical pulp is formed, then mixed with a caustic agent, followed by contact with a delignifying fluid. Water is drained off the slurry without reduction of pressure and while maintaining temperature following which the resulting slurry is maintained under these temperature and pressure conditions for a discrete period of time. The thus-obtained treated slurry is then washed.
    Type: Grant
    Filed: July 22, 1987
    Date of Patent: May 30, 1989
    Assignees: Waagner-Biro Aktiengessellschaft, Steyrermuhl Papierfabriks-und-Verlags-Aktiengesellschaft
    Inventors: Heinz Loquenz, Siegfried Meissl, Helmut Schweiger, Norbert Meindl, Karl Schwarzl, Anton Hruschka