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:
May. 30, 1989
Filed:
Jul. 22, 1987
Heinz Loquenz, Graz, AT;
Siegfried Meissl, Stallhofen, AT;
Helmut Schweiger, Graz, AT;
Norbert Meindl, Gmunden, AT;
Karl Schwarzl, Steyrermuhl, AT;
Anton Hruschka, Vienna, AT;
Waagner-Biro Aktiengessellschaft, both of, AT;
Steyrermuhl Papierfabriks-und-Verlags-Aktiengesellschaft, both of, AT;
Abstract
Method and apparatus for delignifying chemical pulp by means of oxygen, in which an aqueous slurry of chemical pulp is formed, then mixed with a caustic agent, followed by contact with a delignifying fluid. Water is drained off the slurry without reduction of pressure and while maintaining temperature following which the resulting slurry is maintained under these temperature and pressure conditions for a discrete period of time. The thus-obtained treated slurry is then washed.