Method for continuous cooking of cellulose-containing fibre material
US6179958A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1998 |
| Grant date | Jan 30, 2001 |
| Priority date | — |
| Expiry date | Jul 29, 2018 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C3/24
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for cooking chips, involving steaming the chips, impregnating the chips with impregnating liquid in an impregnation vessel, which impregnating liquid comprises fresh cooking liquid and spent liquor, extracting spent liquor from the impregnation vessel, cooking the impregnated chips in cooking zones including an introductory co-current cooking zone and a concluding counter-current cooking zone, extracting spent liquor from the digester at a position between the said co-current and counter-current cooking zones, transferring the said spent liquor from the digester to at least one position upstream of the digester, circulating the cooking liquid in a bottom circulation within the said counter-current cooking zone, heating the circulating cooking liquid by means of heat exchange, and supplying wash liquid to the bottom of the digester. According to the invention, at least some of the digester extract, before being transferred to the said position upstream of the digester, undergoes heat exchange with at least some of the cooking liquid in the said bottom circulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.