Volume 9, No. 1, March 2009, Pages 50-64 PDF(315 KB)
Evaluation of Multichannel Annular Denuders for a Newly Developed Ultrafine Particle Sampling System
K. Sekiguchi1, K. H. Kim1, S. Kudo1, K. Sakamoto1, Y. Otani2, T. Seto2, M. Furuuchi2, F. Yoshikawa3, K. Ehara4, M. Hirasawa4, N. Tajima5, T. Kato5
1 Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura, 338-8670, Saitama, Japan
2 Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, 920-1192, Kanazawa, Japan
3 Kanazawa Institute of Technology, 7-1 Ohgigaoka Nonoichi, 921-8501, Kanazawa, Japan
4 National Institute of Advanced Industrial Science and Technology, Tsukuba Central 2, 305-8568, Tsukuba, Japan
5 Japanese Kanomax Inc., 2-1 Shimizu Suita, 565-0805, Osaka, Japan
Laboratory studies evaluated the gas collection efficiencies and particle transmission efficiencies of 1-, 3-, 5-, and 8-channel denuders under simulated atmospheric conditions with the goal of combining an annular denuder–filter pack (AD-FP) system with a newly developed inertial classification. The multichannel denuders having large surface areas were considered for this AD-FP system since the inertial classification system operates at a flow rate of 40 L/min. Gas collection efficiency was measured with phosphorous acid–coated denuders targeted on ammonia gas. Particle transmission efficiency was measured for ammonium sulfate particles. The denuder-coating procedure and the method for extracting the multichannel denuders are described in detail. Gas collection efficiencies for the 1-, 3-, 5-, and 8-channel denuders were 96.3, 98.6, 98.2, and 98.3% (1-ch < 5-ch, 8-ch, and 3-ch), respectively. The extraction efficiency was greater than 96% for all but the 8-channel denuder (92%). The particle transmission efficiencies for the 1-, 3-, 5-, and 8-channel denuders at 40 L/min were 97.3, 97.4, 94.7, and 93.4% (8-ch < 5-ch < 1-ch and 3-ch), respectively. These results indicate that a 1- or 3-channel denuder can be effectively used in this AD-FP system at a flow rate of 40 L/min.
Multichannel annular denuder; Gas collection efficiency; Particle loss; Extraction efficiency.