Dissolved solids control in pulp production
US5620562A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1996 |
| Grant date | Apr 15, 1997 |
| Priority date | — |
| Expiry date | Apr 3, 2016 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21G7/00
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.