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. 07, 1990
Filed:
Jan. 19, 1989
Applicant:
Inventors:
Robert G Lee, Montreal, CA;
Derek Hornsey, Beaconsfield, CA;
Jose Dieguez, St-Bruno, CA;
Arthur S Perkins, Moraga, CA (US);
Assignee:
Canadian Liquid Air Ltd./Air Liquide Canada, Montreal, CA;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21C / ;
U.S. Cl.
CPC ...
162 49 ; 162 63 ; 162 65 ; 162236 ; 162D / ; 162D / ; 73 2503 ;
Abstract
An inert gas such as helium is employed as a tracer gas in a pulp and paper mill to determine the utilization of oxygen by an aqueous cellulosic pulp particularly, as well as other parameters, in an oxygen delignification or extraction in which oxygen is dissolved in the pulp and reacted to solubilize lignins and reduce the requirement for chlorine-based bleaching chemicals.