Process for decreasing the charge of chemical required in a chlorine bleaching extraction stage
US5126009A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1990 |
| Grant date | Jun 30, 1992 |
| Priority date | — |
| Expiry date | Jun 26, 2010 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/14
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is an improved chlorinated pulp bleaching process and apparatus which reduces caustic requirements significantly, wherein the washed chlorinated pulp, after first separating therefrom the effluent from the chlorination stage washing step, is treated with recycled alkaline extraction stage effluent in an additional washing step between the chlorination stage washing step and the extraction stage washing step; and wherein the effluent from the additional washing step is separated from the twice-washed pulp and, optionally wherein that effluent is recycled as shower water for the chlorination stage washing step, before the twice washed pulp is mixed with the caustic in the extraction stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.