Two-stage pulp thickening
US4100069A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 28, 1977 |
| Grant date | Jul 11, 1978 |
| Priority date | — |
| Expiry date | Feb 28, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D35/22
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An apparatus for thickening pulp at the bottom of a diffusion washing tower. Two sets of concentric screens are provided, each screen set comprising a plurality of radially spaced screens, the screens of one of the screen sets being radially offset from the screens of other screen sets. A plurality of hollow mounting arms each commonly mount the screen sets and are in operative fluid communication with at least some of the screens of the screen sets. Screened liquid is withdrawn from the hollow mounting arms, and the hollow mounting arms and screen sets are axially reciprocated during the screening operation. Control of the homogeneity of the pulp is effected by preventing fluid communication between the interior of screens of the different screen sets, and two separate withdrawal devices are provided, one for withdrawing liquid only from one of the screen sets, and one for withdrawing liquid only from the other of the screen sets. The operation of the two withdrawal structures can be controlled so that extraction flow rates from the sets are substantially equal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.