Desiccant for drying CH2F2 refrigerant utilizing zeolite
US6313059A · kind A · utility
Inventors
Key dates
| Filing date | Sep 28, 2000 |
| Grant date | Nov 6, 2001 |
| Priority date | — |
| Expiry date | Sep 28, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B43/003
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Difluoromethane (R-32) is of current interest as a partial replacement for chlorodifluoromethane (R-22) refrigerant heretofore widely used in vapor compression refrigeration systems. R-32 has, however, proved to be more reactive than is desirable with the zeolite A adsorbent-desiccant compositions used in such systems to prevent corrosion and freeze-up problems. The potassium cation form of a zeolite A molecular sieve--with at least 60 percent of the sodium cations replaced with potassium ions, agglomerated with a clay binder, and pore-reduced to essentially exclude the adsorption of R-32 having essentially no reactivity with difluoromethane, and having a surface ratio of silicon to aluminum of less than about 1.7 mol/mol as determined by X-ray photoelectron spectroscopy--has been found to be an effective desiccant for refrigerants comprising difluoromethane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.