Influence of Electrostatic Discharge Circuit Parameters on the Minimum Ignition Energy of Suspended Dust Clouds

분진운의 최소점화에너지에 대한 정전기 방전회로의 매개변수 영향

  • Moon, Kyoon-Tae (The Graduate School of Energy and Environment, Seoul National University Science and Technology) ;
  • Chung, Jae-Hee (The Graduate School of Energy and Environment, Seoul National University Science and Technology) ;
  • Yamaguma, Mizuki (Japan National Institute of Occupational Safety and Health) ;
  • Choi, Kwang-Seok (Japan National Institute of Occupational Safety and Health)
  • 문균태 (서울과학기술대학교 에너지환경대학원) ;
  • 정재희 (서울과학기술대학교 에너지환경대학원) ;
  • 미주키 야마구마 (일본노동안전위생종합연구소) ;
  • 최광석 (일본노동안전위생종합연구소)
  • Received : 2010.07.12
  • Accepted : 2010.10.06
  • Published : 2010.10.31

Abstract

The ignitability(minimum ignition energy, MIE) of a suspended dust clouds is very important aspect of technical safety indices. This paper reported the experimental results dealing with the influence of discharge circuit on the MIE of a suspended dust clouds. The movement of a suspended dust clouds was also observed with the high speed camera. The Hartmann vertical-tube apparatus(MIKE-3) described in the international standard of IEC and Polypropylene (PP, 50% volume-average, D50: $761{\mu}m$) resin powders were used in this experiment. The following results were obtained: (1) the MIE of a suspended PP powder depended markedly on the discharge circuit; in other words, when a resistor was connected in series with the discharge sparking circuit(RC), the lowest value(31mJ) of MIE was obtained for a suspended PP powder comparison with the other circuits(C circuit; 370mJ or LC circuit; 71mJ). (2) the discharge duration time is more important than other factors with regard to MIE of a suspended PP powder.

References

  1. 최영상, "분진폭발의 현상과 방지대책에 관한 고찰", 소방논문지 제5호, pp. 105-131, 2001.
  2. 鄭國三外, "安全工學實驗", 東和技術, p. 19, 1992.
  3. IEC 1241-2-3, "Electrical apparatus for use in the presence of combustible dust - part 2 : test methods", pp. 9-10, 1994.
  4. APPIE SAP, "Test method for minimum ignition energy of combustible dust/air mixtures", pp. 1-17, 2010.
  5. K. S. Choi, M. Yamaguma, T. Kodama, T. Y. Kim, J. H. Joung, M. Nifuku and M. Takeuci, "Influence of discharge conditions on the ignitability of lycopodium streams due to a single capacitance discharge spark", KIEE International Transactions on Elextro-physical and Application(in English), Vol. 3-C, No. 3, pp. 99-105, 2003.
  6. 田中隆二, 本質安全防爆電気回路に關する基礎的 研究, 勞働省産業安全研究所(現:勞働安全衛生 總合研究所), 1970.
  7. 신대성, "전기스파크에 의한 분체도료의 착화위험성에 관한 연구", 공학박사학위 논문, pp. 11, 2008.
  8. W. Ishihama, "Studies on the Ignition Energy of Dust Clouds", J. Japan society for safety engineering, Vol. 21, No. 5, pp. 273-27, 1982.
  9. Ch. Cesana and R. Siwek, "Mike 3 Minimum ignition Energy 3.3", pp. 6-10, 2001.