DOI QR코드

DOI QR Code

혼합효과가 DMA와 CPC를 이용한 입자분포 측정에 미치는 영향에 관한 연구

Study on the Influence of Mixing Effect to the Measurement of Particle Size Distribution using DMA and CPC

  • 이윤수 (한국과학기술원 기계공학과 입자공학연구실) ;
  • 안강호 (한양대학교 기계공학과) ;
  • 김상수 (한국과학기술원 기계공학과)
  • 발행 : 2003.03.01

초록

In the measurement using DMA and CPC in series, there is some time delay for particles classified in DMA to detect in CPC. During this time, the DMA time-response changes due to the velocity profile of sampling tube and the diffusion of particles in the volume that exists between the DMA exit and the detector of ultra-fine CPC. This is called mixing effect. In the accelerated measurement methods like the TSI -SMPS, the size distribution is obtained from the correlation between the time-varying electrical potential of the DMA and the corresponding particle concentrations sampled in DMA. If the DMA time -response changes during this delay time, this can cause the error of a size distribution measured by this accelerated technique. The kernel function considering this mixing effect using the residence time distribution is proposed by Russell et al. In this study, we obtained a size distribution using this kernel to compare to the result obtained by the commercial accelerated measurement system, TSI -SMPS for verification and considered the errors that result from the mixing effect with the geometric mean diameters of originally sampled particles, using virtually calculated responses obtained with this kernel as input data.

키워드

참고문헌

  1. Fissan, H. J., Helsper, C., and Thielsen, H. J., 1983, 'Determination of Particle Size Distributions by Means of an Electrostatic Classifier,' Journal of Aerosol Science, Vol. 14, pp. S354-357 https://doi.org/10.1016/0021-8502(83)90133-7
  2. Shih Chen Wang and Richard C. Flagan, and John H. Seinfeld, 1990, 'Scanning Electrical Mobility Spectrometer,' Aersol Science and Techology, Vol.13, pp.230-240 https://doi.org/10.1080/02786829008959441
  3. Lynn M. Russell, Richard C. Flagan, and John H. Seinfeld, 1995, 'Asymmetric Instrument Response Resulting from Mixing Effects in Accelerated DMA-CPC Measurements,' Aersol Science and Techology, Vol.23, pp.491-509 https://doi.org/10.1080/02786829508965332
  4. Kang-Ho Ahn, Nam-hyo Kim, Jong-ho Lee, Gwi-Nam Bae, 1996, 'Particle Path and Performance Evaluation of Differential Mobility Analyzer,' KSME Jouranl(B), Vol. 20, No.6, pp.2005-2013
  5. A. Wiedensohler, 1988,'An approximation of the Bipolar Charge Distribution for Particles in the Submicron Size Range,' Journal of Aerosol Science, Vol. 19, No. 3, pp. 387-389 https://doi.org/10.1016/0021-8502(88)90278-9
  6. Abde Kapadia, 1980,'Data Reduction Techniques for Aerosol Size Distribution Measuring Instruments,' Ph.D. Thesis in the University of Minnesota