Apparatus and method for thickening pulp and paper stock
US4722793A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1987 |
| Grant date | Feb 2, 1988 |
| Priority date | — |
| Expiry date | Mar 23, 2007 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/18
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Apparatus for thickening a suspension of pulp material employs a single pair of liquid-impervious rolls and a single loop of wire trained around both rolls which are spaced from each other in substantially the same horizontal plane. The pulp stock to be thickened is delivered into the wedge zone defined by the upper wire run approaching the top of one roll and the surface of that roll, so that the pulp is trapped between the wire and roll as it travels around the roll with the wire, and the rolls are driven at sufficient speed to develop centrifugal forces which cause liquid to be expressed through the wire from the pulp trapped against the roll. The resulting partially dewatered pulp is redeposited from the first roll onto the lower wire run for travel to the other roll, where it is similarly subjected to centrifugal force for further expression of liquid through the wire, after which the pulp is removed from the surface of the second roll in the wedge zone defined by the surface of that roll and the wire run travelling therefrom to the first roll.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.