Reducing pulp mill liquid discharge
US5380402A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1992 |
| Grant date | Jan 10, 1995 |
| Priority date | — |
| Expiry date | Oct 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S162/08
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A pulp mill has zero or minimum liquid discharges. The large amounts of liquid that must be processed to achieve this result are handled utilizing a multiple effect evaporator provided with heat from a steam exhaust of a condensing type steam turbine. Super heated steam from the recovery and bark boilers is fed to the turbine to generate electricity for the production of bleaching chemical and other uses in the mill. Three or four steam exhausts having different composite temperature and pressure values are taken from the turbine and used where most suitable in the pulp mill. For evaporation of bleach plant effluent the steam taken from the turbine preferably has a pressure of about 1-3 psia and a temperature of about 120.degree.-140 .degree. F, and has no significant adverse affect on power generation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.