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.

Date of Patent:
Apr. 05, 1994

Filed:

May. 31, 1988
Applicant:
Inventors:

Johan C Richter, Oslo, NO;

Ole J Richter, Karlstad, SE;

Assignee:

Kamyr AB, Karlstad, SE;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ; D21C / ;
U.S. Cl.
CPC ...
162246 ; 162251 ;
Abstract

In the continuous cooking of comminuted cellulosic fibrous material (e.g. wood chips) to produce paper pulp, the material is subjected to a minimum of mechanical action, especially under high temperature and pressure conditions, so as to increase the quality of the pulp. Also, even for large digesters the uniformity of treatment is enhanced, and scaling may be reduced while energy efficiency is increased. Material is fed without significant steaming to a feeder screw within a perforated cylinder mounted at the bottom of an impregnation vessel. The material flows upwardly in the impregnation vessel, with screens adjacent the top of the vessel thickening the slurry before it is discharged into the top of a continuous digester. The discharge from the impregnation vessel to the continuous digester is made with a minimum of mechanical action on the pulp. The impregnation vessel may be disposed within, and concentric with, the digester, or it may located exteriorly of the digester and supply more than one digester. Conduits mounted on the exterior of the impregnation vessel, when concentric with the digester, can supply treatment liquid at various locations along the height of the digester.


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