Method and apparatus for purifying hydrogen fluoride
US4952386A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1988 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | May 20, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/14
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for purifying hydrofluoric acid, comprising the steps of filtering the hydrofluoric acid to remove particulates, passing the filtered acid through a cation exchange material and an anion exchange material to remove ions therefrom, at least periodically automatically monitoring the acid that has passed through at least a predetermined portion of the cation exchange material for a predetermined level of cationic impurity representative of actual or impending ionic breakthrough in the cation exchange material, at least periodically automatically monitoring the acid that has passed through at least a predetermined portion of the anion exchange material for a predetermined level of anionic impurity representative of ionic breakthrough in the anion exchange material, automatically interrupting flow of acid through the anionic or cationic exchange material at or prior to the time the breakthrough in such material occurs, while the flow is interrupted, regenerating the anionic or cationic exchange material, resuming the flow after the exchange material is regenerated, passing the acid from the cationic and anionic exchange materials through an ultrafilter and into a storage contai…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.