Particle Generator for Testing ULPA and HEPA Filters
Particle Generator using PSL spheres as particle challenge.
The upstream particle count of the filter challenge is extremely important, since a 6/9 ULPA filter has the capability to trap 99.9999% of all particles flowing through the filter, which is 1 particle out of 1 million particles trapped by the 6/9 ULPA filter. Thus a very high, upstream particle count of at least 8x10 E10 at 0.10μm particles per minute is needed to sustain the upstream particle challenge for a 2x4 foot HEPA filter. A Particle Generator is needed to provide this high particle count challenge. The Polystyrene Latex spheres are mixed with the appropriate air flow volumes of 700 CFM, 1000 CFM or 2000 CFM, to provide a uniform airflow to the upstream filter.
Particle Generator Desired Goals
- Particle Generation to challenge ULPA and HEPA filters is accomplished between 01. micron and 0.5 micron particle size
- Output is generally required 1x10 E10 Polystyrene Latex particles per cubic foot of airflow volume
- Minimize doublet and triplet formation
- Minimize double and triple charged particles
- Water is desired but oil can also be used as the carrier fluid
- Instant On and Off Power Control is desired for filter challenge control
- Laser particle Counter on the downstream and upstream side of the filters
- Constant particle output of the particle generator over long periods of operation