Mixture of oppositely charged filter aid material
US4177142A · kind A · utility
28Cited by
4References
24Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 27, 1977 |
| Grant date | Dec 4, 1979 |
| Priority date | — |
| Expiry date | Sep 27, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D37/03
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Impurities are removed from a liquid by passing the liquid through an improved filter bed. The filter bed comprises a mixture of oppositely charged particles of filter aid material, the particles normally having a surface charge in aqueous solution. A portion of these particles are treated with a chemical compound to produce a surface charge that is opposite from the normal surface charge. These oppositely charged particles clump in aqueous suspension, and produce a filter bed which is capable of removing suspended particles with very high efficiency, while maintaining a relatively low pressure drop across the filter bed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.