Service life indicator for chemical filters
US7875100B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 2010 |
| Grant date | Jan 25, 2011 |
| Priority date | — |
| Expiry date | May 21, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S55/34
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method is provided for indicating the useful service life of a gas filtration and purification system comprising steps of embedding two or more mass-responsive electronic sensors (e.g., surface acoustic wave devices) in a sorbent bed of a filtration cartridge, wherein the mass-responsive electronic sensors are coated with a non-conductive absorptive organic polymer; passing a gas containing a volatile chemical of interest through the filtration cartridge and in contact with the two mass-responsive electronic sensors; and measuring a difference in an electronic property between the two mass-responsive electronic sensors. In such a manner, the two mass-responsive electronic sensors act as internal references with respect to each other, thereby eliminating variations in temperature, interferents, pressure, and the like. When the volatile compound is no longer retained by the sorbent bed, a difference electronic properties of the mass-responsive sensors indicates that the filtration cartridge should be replaced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.