Microwave drying process for synthetic polymers
US4055001A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 1975 |
| Grant date | Oct 25, 1977 |
| Priority date | — |
| Expiry date | Sep 25, 1995 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF26B3/343
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Volatile polar vehicles such as water or organic solvents, are removed from nonpolar materials by passing said material through at least one pneumatic conveyor resonating cavity operating at a microwave frequency of about 600 to about 50,000 MHZ. For example, a polymer such as polyvinyl chloride may be dried by conveying the polymer through said pneumatic conveyor operating at a frequency of 915 MHZ for a time sufficient to reduce the volatiles content to about 5 wt. % and subsequently conveying the partially dried material through a second pneumatic conveyor resonating cavity operating at a microwave frequency of 2450 MHZ for a time sufficient to reduce the polar vehicle content to below 0.5 wt. %. The resonating cavities may constitute a single pneumatic conveyor having zones operating at different frequencies, said zones being isolated from one another by microwave suppressors such as "eggcrate" type suppressors. Alternately, several pneumatic conveyor systems, each operating at a different frequency, may be used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.