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:
Oct. 20, 1998
Filed:
Feb. 18, 1997
Johan Richter, Oslo, NO;
Ole Richter, Karlstad, SE;
Kvaerner Pulping AB, , SE;
Abstract
The present invention relates to a method for continuously producing pulp in which finely divided fiber material, preferably wood chips, is impregnated in an impregnation vessel (10), preferably by being fed in at the top (14) and fed out from the bottom (16) of the said vessel (10), in which cooking pressure essentially prevails in the said first vessel (10). The impregnation vessel, preferably, does not have a screen. The chips are heated and impregnated with the aid of black liquor that is concurrently flowing with a flow of the wood chips which have been thoroughly impregnated with boiling hot black liquor are transferred to the top (28) of a steam-phase digester (12). The pulp is permitted to flow passed at least one screen girdle (32) for drawing off spent liquor. The drawn off spent liquor has a high amount of effective alkali. The upper portion of the digester (12) has an effective alkaline level that is higher than the effective alkali level at the lower portion of the digester but the temperature in the lower portion of the digester is higher than the temperature in the upper portion thereof.