The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 21, 1990
Filed:
Oct. 03, 1988
Frey Frejborg, Glens Falls, NY (US);
A. Ahlstrom Corporation, Noormarkku, FI;
Abstract
An apparatus for screening pulp comprises a vessel, a cylindrical screen within the vessel, a rotor moving in the vicinity of the screen at a predetermined speed, an inlet for the unscreened pulp, an outlet for the screened pulp in the vessel. The rotor is non-cylindrical, for instance, elliptical, triangular and, in general, is multi-cam. The rotor has a contour surface, for instance grooves formed of a first bottom plane parallel to the envelope surface, an inclined plane, an upper plane and a side plane, the side plane being essentially perpendicular to the first bottom plane, the inclined plane forming an angle between 5 degrees and 60 degrees with the first plane, the upper plane being parallel to the first plane. The contour surface of the rotor may also be achieved by attaching bars of the contoured shape to the surface of the rotor, for instance by welding.