Patents by Inventor Pirkko Virta

Pirkko Virta 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).

  • Catalyst and process for purifying diesel exhaust gases
    Patent number: 5580533
    Abstract: The invention relates to a catalyst intended for purifying diesel exhaust gases, the catalyst comprising a honeycomb and a support which has been prepared by using titanium dioxide and an inorganic sol, and at least one catalytically active agent.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: December 3, 1996
    Assignee: Kemira OY
    Inventors: Matti Kivioja, Sointu Ravola, Thomas Slotte, Teuvo Maunula, Matti H ark onen, Pirkko Virta
  • Use of a super alloy as a substrate for catalysts
    Patent number: 5534476
    Abstract: A metal alloy in which the highest individual metal concentration is nickel and which always includes at minimum 4% by weight aluminum is used as the substrate for catalysts for purifying exhaust gases. Chromium, iron, cobalt, molybdenum and titanium are among the other metals possible.
    Type: Grant
    Filed: June 23, 1994
    Date of Patent: July 9, 1996
    Assignee: Kemira Oy
    Inventors: Marjo Luoma, Keijo Torkkell, Reijo Lylykangas, Pirkko Virta
  • Process for the preparation of hydrogen peroxide (I)
    Patent number: 5071634
    Abstract: The invention relates to a process for the production of hydrogen peroxide by the anthraquinone process. A reaction mixture into which there are fed hydrogen or a hydrogen-containing gas and a working solution, i.e. an anthraquinone derivative in an organic solvent, is circulated via a tubular static mixing zone (9) which is continuous or comprises several parts, in order to hydrogenate the anthraquinone derivative in the presence of a solid catalyst, and by removing hydrogenated working solution (13) and gas (11) from the circulating reaction mixture (8). According to the invention, the reaction mixture (14) is circulated (8) via a catalyst-coated static mixing zone (9), where it is simultaneously both mixed and catalyzed.
    Type: Grant
    Filed: January 24, 1990
    Date of Patent: December 10, 1991
    Assignee: Kemira Oy
    Inventors: Teuvo Maunula, Eva-Liisa Mustonen, Ilkka Turunen, Pirkko Virta