Probe-in-Bed Technique for Determination of Residual Gas Life of Charcoal Filters.
Abstract
Probe-in-bed testing with CK was completed for phases, IA, IB and II. Because the adsorption front extends over the total M11 test-bed length, probes representing 25%, 50% and 75% of total gas life are all within 0.9 cm or 33% from the effluent end of the bed. Distances of 0.05 cm are critical and because the probe diameter is 0.12 cm and whetlerite granule diameter range is from 0.06 to 0.17 cm, correct location of probe is difficult. The probes always measure percentages of the total gas life regardless of length of total gas life. This was true also of phase II tests on whetlerites that had been aged or exposed to sulfur dioxide, formaldehyde or xylene vapors and where the total gas lives were very short. Some of the better test results showed that it was possible to measure the gas life at the 75% probe within + or - 6% of the calculated life. Phase IB tests involving intermittent flow of CK-air and pure air through the canister, showed that no CK drifted from one probe to the next with pure air flow. CK concentration at a probe, after breakthrough at 0.008 mg/1 occurred, dropped to zero in about 3 minutes with pure air flow and when CK was introduced into the gas stream recovery time to 0.008 mg/1 was also about 3 minutes. This means that in field test units, the test gas must be metered into the filter for several minutes before a reliable indication is obtained on residual gas life.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1976
- Accession Number
- ADA032795
Entities
People
- A. J. Juhola