Process for removing colloidal suspensions from a liquid
US4140609A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 1978 |
| Grant date | Feb 20, 1979 |
| Priority date | — |
| Expiry date | Feb 17, 1998 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C11/0007
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A system and method for removing colloidal suspensions or particles from a liquid, in particular tall oil soap particles from black liquor of a wood pulping process. Black liquor is moved along a flow path from an upstream to a downstream zone. First and second electrical conductors are respectively located in the upstream and downstream zones and means are provided for applying opposite electrical potentials to these conductors. For removal of anionic colloids, the first conductor is made positive and the second conductor negative. Thus, colloidal particles in the liquid having a relative potential opposite to the potential of the first conductor are attracted towards the first conductor as the liquid flows through the upstream zone, and some of the ions attached to some of these particles are stripped off by the electrical field, leaving these particles with a potential of the opposite polarity from particles not so affected. The stripped colloidal particles attract other colloidal particles the charge of which has not been changed by stripping, thereby commencing the formation of agglomerates. The particles are carried downstream by the liquid and through the field adjacent the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.