Method for dewatering of sludge from a pulp, paper or board making process
US10858782B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2017 |
| Grant date | Dec 8, 2020 |
| Priority date | — |
| Expiry date | Feb 4, 2038 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/64
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method is disclosed for dewatering of sludge from a pulp, paper or board making process, such as deinking sludge, including obtaining of an aqueous sludge including an aqueous phase and a fibre material suspended in the aqueous phase. The sludge is subjected to a pre-thickening step, where a first part of the aqueous phase is removed from the sludge and to a pressing step, where a second part of the aqueous phase is removed from the sludge, thereby obtaining a dry pressed sludge. Before or at the pre-thickening step a polymer composition having a charge density of at the most 1.7 meq/g, preferably at most 1.5 meq/g, more preferably at most 1.1 meq/g, is added to the sludge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.