Method for the continuous cooking of pulp
US5824187A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1997 |
| Grant date | Oct 20, 1998 |
| Priority date | — |
| Expiry date | Feb 18, 2017 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C3/24
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to a method for continuously producing pulp in which finely divided fiber material, preferably wood chips, is impregnated in an impregnation vessel (10), preferably by being fed in at the top (14) and fed out from the bottom (16) of the said vessel (10), in which cooking pressure essentially prevails in the said first vessel (10). The impregnation vessel, preferably, does not have a screen. The chips are heated and impregnated with the aid of black liquor that is concurrently flowing with a flow of the wood chips which have been thoroughly impregnated with boiling hot black liquor are transferred to the top (28) of a steam-phase digester (12). The pulp is permitted to flow passed at least one screen girdle (32) for drawing off spent liquor. The drawn off spent liquor has a high amount of effective alkali. The upper portion of the digester (12) has an effective alkaline level that is higher than the effective alkali level at the lower portion of the digester but the temperature in the lower portion of the digester is higher than the temperature in the upper portion thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.