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:
Jan. 13, 1998
Filed:
Dec. 03, 1996
Larry D Markham, Mobile, AL (US);
International Paper Company, Purchase, NY (US);
Abstract
A process for cleaning recycled pulp includes an upright cylindrical vessel having an upright cylindrical screen member open at its top and bottom ends and having a perforated screen wall which is centered on a vertical axis in the vessel. A plurality of upright, elongated blades are mounted for rotation on the vertical axis in close proximity to the screen wall. A pulp slurry entrained with pressurized air is introduced under pressure into an inlet in the bottom of the vessel. The rotating blades clear the screen wall while creating a rising vortex of air bubbles produced by the pressurized air for carrying ink and/or contaminant particles upwardly through the inner volume of the screen member. An 'accepts' outlet at the center of the vessel draws off pulp in suspension that has been passed through the screen wall. A 'rejects' outlet at the top of the vessel draws off ink and contaminant particles carried by the air bubbles in the upwardly-moving vortex. In related processes, the pulp slurry is processed in successive screen stages to refine the rejects stream to a high concentration while passing an accepts stream of high brightness and cleanliness.