Heaterless dryer having variable cycle
US4605425A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 1985 |
| Grant date | Aug 12, 1986 |
| Priority date | — |
| Expiry date | May 6, 2005 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2259/402
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method and apparatus for fractionating a mixture of gasses, by using a bed of sorbent which is conditionally depressurized and purged after adsorption intervals of a predetermined time duration, varies the time duration in response to demand as indicated by the decisions of whether purging is required. Preferably a historical record is kept of the recent purge decisions, and based upon this historical record, the duration of the adsorption interval is increased at a limited rate up to a maximum duration when purging is infrequently required, and is decreased at a limited rate down to a minimum duration when purging is frequently required. The method and apparatus is particularly suited to drying air or other gasses using a heaterless pressure-swing dehydrator of the kind having two alternately-switched desiccant beds, and capacitance probes inserted in the middle of each bed for sensing the advance of the moisture fronts to determine whether purge is required at the end of the respective adsorption interval.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.