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. 08, 2002
Filed:
May. 11, 2000
C. Bertil Stromberg, Glens Falls, NY (US);
Andritz-Ahlstrom Inc., Glens Falls, NY (US);
Abstract
A system and method for feeding a slurry of comminuted cellulosic fibrous material such as wood chips to the top of a treatment vessel such as a continuous digester also treat the material to remove metals before digestion. During pumping of the slurry with at least first and second series connected pumps, at or upstream of at least one of the pumps chemicals (acids and/or chelating agents) which dissolve the metals in the material are added, and preferably some of the liquid is removed so as to purge at least about 10% (e.g. about 20-80%) of the metals in the material. The metal removal preferably takes place substantially immediately before alkaline digestion.