System for sulfonating mechanical pulp fibers
US5089089A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 3, 1989 |
| Grant date | Feb 18, 1992 |
| Priority date | — |
| Expiry date | Nov 3, 2009 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/004
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A two stage sulfonation system includes a mixing tank, a retention tank, a thickening press, a pressurized vessel, and a liquor recovery press in series relation. A sodium sulfite generation unit is connected to maintain a supply of sodium sulfite solution in a holding tank from which a controlled quantity of said solution is metered and injected in the mixing tank. Liquor extracted in the thickening press is cycled back to the mixing tank. Liquor extracted in the recovery press is moved to an intermediate tank and then transferred to the sodium sulfite generation unit, there fortified with fresh sodium sulfite and forwarded to the holding tank to maintain therein an appropriate supply to service the system. The system is designed to receive mechanical pulp, in a slurry form, first introduced into the mixing tank simultaneously with a metered charge of sodium sulfite solution from the holding tank, the sodium sulfite content of which is at a level from about 40 to about 200 g/l. The solution is mixed into the slurry to provide a relatively uniform and intimate contact thereof with its fiber content. This slurry is transferred to the retention tank and there held subject to a sub-bo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.