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AssigneeKamyr, Inc.
InventorsBruno S. Marcoccia, J. Robert Prough, Richard O. Laakso, Joseph R. Phillips, Rolf C. Ryham, Jan T. Richardsen, R. Fred Chasse
Estimating the term…
Kraft pulp of increased strength and bleachability may be produced with decreased consumption of effective alkali, and at a lower H factor, by keeping the dissolved organic material (DOM) concentration low substantially through the entire kraft cook, including by extracting high DOM liquid from at least one part of a continuous digester and replacing it with much lower level DOM liquid. Existing pulp mills having two-vessel hydraulic, one-vessel hydraulic, or other systems may be retrofit to provide for extractions and additions of low DOM dilution liquor (including substantially DOM-free white liquor). Also, commercial size batch digesters (8 tons per day of pulp or more) can be operated with low DOM liquor to produce increased strength pulp. Using dilution with low DOM liquor also results in reduced H factor and effective alkali consumption, and increased bleachability.
A method of kraft cooking comminuted cellulose fibrous material at a rate of at least 8 tons of pulp per day in a single batch digester comprising the steps of (a) cooking the comminuted cellulosic fibrous material to produce pulp and liquor surrounding the pulp which contains effective dissolved lignin concentration and (b) maintaining the effective dissolved lignin concentration at about 50 g/l or less throughout substantially the entire kraft cook and wherein the effective dissolved lignin concentration is obtained by continuously passing substantially dissolved organic material-free cooking liquor into and out of contact with the cellulose material until completion of the kraft cooking thereof.
A method of kraft cooking comminuted cellulose fibrous material at a rate of at least 8 tons of pulp per day in a single batch digester comprising the steps of (a) cooking the comminuted cellulosic fibrous material to produce pulp and liquor surrounding the pulp which contains effective dissolved hemi-cellulose and (b) maintaining the effective dissolved hemi-cellulose concentration at 15g/l or less throughout substantially the entire kraft cook and wherein the effective dissolved hemi-cellulose concentration is obtained by continuously passing substantially dissolved organic material free cooking liquor into and out of contact with the cellulose material until completion of the kraft cooking thereof.
A method of producing kraft pulp by cooking comminuted cellulosic fibrous material comprising the steps of continuously, at least one stage during kraft cooking of the material to produce pulp and liquor surrounding the pulp which contains effective dissolved organic material;
A method of producing kraft pulp by cooking comminuted cellulosic fibrous material comprising the steps continuously, at least one stage during kraft cooking of the material to produce pulp and liquor surrounding the pulp which contains effective dissolved organic material;
A method of producing kraft pulp by cooking comminuted cellulosic fibrous material comprising the steps of continuously, at at least one stage during kraft cooking of the material to produce pulp and liquor surrounding the pulp which contains effective dissolved organic material;
Dependencies are inferred from the claim text.