Two-stage digestion with between vessel heating
US4104113A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1976 |
| Grant date | Aug 1, 1978 |
| Priority date | — |
| Expiry date | Jun 21, 1996 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C7/00
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An apparatus and method for the digestion of cellulosic fiber material providing pulp of very uniform quality. Cellulosic fiber material entrained in treatment liquid is fed into a top portion of a first vertical treatment vessel, impregnation of the fiber material with treatment liquid taking place in the first vessel. A first flow path of fiber material entrained in and impregnated with treatment liquid is established from the bottom of the first vessel to a top portion of a separate second vertical treatment vessel, liquid substantially filling the second vessel. Liquid is withdrawn from the top portion of the second vessel (without screening) and a second flow path is established of the liquid withdrawn from the second vessel back toward the bottom portion of the first vessel, heating of the liquid during transport in the second flow path taking place. A portion of the heated liquid flowing in the second flow path is fed into the first flow path, while the remainder of the heated liquid is fed to a bottom portion of the first vessel, the bottom portion of the first vessel serving as the heating chamber. Washing as well as digesting may taken place in the second vessel, the unif…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.