Air filtration system with safety after-filter
US5271750A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1992 |
| Grant date | Dec 21, 1993 |
| Priority date | — |
| Expiry date | Sep 1, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D46/2407
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An air filtration system with a safety after-filter that prevents contaminated air being exhausted by using a backup filter and with a mechanism to detect tears or leaks in the primary filters. The safety after-filter assembly attaches to the exhaust of an air filtration system and collects dirt particles which get by the primary filters. Detection of rips, tears, or leaks in the primary filters is accomplished by monitoring the air pressure difference across the safety after-filter and is measured by a differential pressure gauge. If a primary filter develops a tear or leak, the safety after-filter quickly becomes clogged with dirt and the pressure difference across the safety after-filter increases. If the safety after-filter itself develops a tear or leak, the pressure difference across the safety after-filter decreases. Either condition causes alarms to be triggered and the system is powered down, thus preventing contaminated air being exhausted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.