Method for producing deionized water
US6565725B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2001 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Mar 2, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2201/46115
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for producing deionized water by an electro-regenerating deionization method, which comprises employing a deionized water producing apparatus comprising an electrodialyzer, and ion exchangers being accommodated in the demineralizing compartments, supplying water to be treated in the demineralizing compartments and supplying a concentrated water to the concentrating compartments, wherein the concentrated water at the outlet of the concentrating compartments has a S value of 7 or more as defined by the following formula (1) and a pH of 2.5 or more:S value=(&ggr;−420000×A)/(B×(1−(A/0.004))3)  Formula(1), wherein &ggr; is electro-conductivity(&mgr;S/cm), A is hydrogen ion concentration (mol/l), and B is magnesium ion concentration (ppb).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.