Supply of washing liquid in a fractionating multi-stage washer
US6159338A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1998 |
| Grant date | Dec 12, 2000 |
| Priority date | — |
| Expiry date | Mar 23, 2018 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/08
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method of displacement washing of cellulose pulp achieves substantially optimal results without the consumption of excessive clean wash liquid. In the practice of the method there is at least one washing stage, and a second stage, including a suction, press, and/or thickening stage, following the washing stage. Cellulose pulp is fed to the washing stage, and then the washed pulp is fed to the second stage. A first filtrate is withdrawn from the second stage and a second filtrate is withdrawn from a washing stage of the at least one washing stage, or the second stage. The first filtrate is directed to the washing stage and the first filtrate is used as washing liquid in the washing stage. For example the washing stage may include a last washing stage in a multi-stage fractionating washer, and the second stage may be in the fractionating washer; and the first filtrate may be directed to the last washing stage of the multi-stage fractionating washer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.