Digestion odor control
US3969184A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 19, 1975 |
| Grant date | Jul 13, 1976 |
| Priority date | — |
| Expiry date | Mar 19, 1995 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C11/08
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The invention relates to a continuous method of making cellulosic pulp from wood chips within a range of yield from 65 to 90 per cent by digestion with a digestion liquor containing Na.sub.2 S and Na.sub.2 CO.sub.3. The digestion is effected at temperatures between 150.degree. and 190.degree.C and malodorous sulfur compounds are removed from the pulp, the liquor and the vapors prior to their withdrawal from the digesting process. In order to eliminate their capacity of emitting obnoxious odors, the sulfur compounds are oxidized by addition of molecular oxygen to the digester prior to discharge of pulp and spent liquor from the digester after which the spent liquor is removed from the digested pulp, concentrated and burned for renewed use in preparation of fresh digesting liquor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.