Patents Assigned to Ahlstrom Corp
  • Screening apparatus with light reject removal
    Patent number: 4634521
    Abstract: A screen for fibre pulp is provided with means for removal of light reject. The screening apparatus comprises a vertical cylindrical screen (2); and a rotor (3) which is concentrically disposed inside the screen and the substantially closed outer surface (9) of which together with the inner surface (10) of the screen defines a screening zone (11) for the pulp. A pipe (19) is provided inside the rotor (3) the upper end of the pipe being disposed adjacent to the inner surface (21) of the closed upper end (12) of the rotor (3).
    Type: Grant
    Filed: April 30, 1985
    Date of Patent: January 6, 1987
    Assignees: Ahlstrom Corp, Oy Wilh.Schauman AB
    Inventors: Markku A. Simola, Vesa Haapoja