Production of high purity water using reverse osmosis
US5766479A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1995 |
| Grant date | Jun 16, 1998 |
| Priority date | — |
| Expiry date | Aug 7, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/90
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for purifying water by removing dissolved materials therefrom, the process capable of producing purified water having a resistivity in the range of 2 to 10 megohm-cm. The process comprises providing a water feed stream to be purified and adjusting the pH of the water feed stream to a basic water solution to drive the equilibrium of a first weakly ionized material to become ionized in the basic solution. The basic water solution is introduced to a high pressure side of a first reverse osmosis membrane module and water is passed through the first reverse osmosis membrane to provide a first retentate having ions therein from the first weakly ionized material concentrated therein and a first permeate depleted in ions from the first weakly ionized material. The pH of the first permeate is adjusted to an acidic water solution to drive the equilibrium of a second weakly ionized material to become ionized in an acidic solution. The acidic water solution is transferred to the high pressure side of a second reverse osmosis membrane and the acidic water solution is purified by passing at least a portion thereof through the second reverse osmosis membrane to provide a second retentat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.