Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Characteristics of Unipolar Charging of the Submicron Particles by the Condensation-Evaporation Method

응축 증발법을 통한 서브마이크론 입자의 단극하전 특성

  • 최영주 (한국과학기술원 기계공학과) ;
  • 김상수 (한국과학기술원 기계공학과)
  • Published : 2006.02.01
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Abstract

We applied a new charging system using the condensation and evaporation method to charge the submicron particles with a uniform charging performance. The monodispersed NaCl submicron particles were condensed by n-butanol vapor and grew up to micron droplets with a same size, regardless of their initial size. Those condensed droplets were charged in an indirect corona charger. The indirect corona charger consisted of the ion generation zone and the particle charging zone. In the ion generation zone, Ions were generated by corona discharge and some of them moved into the particle charging zone by a carrier gas and mixed with the condensed droplet. And finally, the charged and condensed droplets dried through an evaporator to shrink to their original size. The average charge and penetration rate of the particles before and after evaporation were measured by CPC and aerosol electrometer and compared with those of a conventional corona charger. The results showed that the average charge was $5\~7$ charges and the penetration rate was over $90\%$, regardless of the initial particle size.

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References

  1. Buscher, P., Ott, A. S. and Wiedensohler, A., 1994, 'Performance of a Unipoar Square Wave Diffusion Charger with Variable Nt-product,' J. Aerosol Sci., Vol. 25, pp. 651-663 https://doi.org/10.1016/0021-8502(94)90006-X
  2. Wiedensohler, A., Buscher, P., Hansson, H. C., Martinsson, B. G., Ferron, F. O. and Busch, B., 1994, 'A Novel Unipolar Charger for Ultrafine Aerosol Particles with Minimal Particle Losses,' J. Aerosol Sci., Vol. 34, pp. 639-649 https://doi.org/10.1016/0021-8502(94)90005-1
  3. Chen, D. R. and Pui, D. Y. H., 1999, 'A High Efficiency, High Throughput Unipolar Aerosol for Nanoparticles,' J. Nanopart. Res., Vol. 1, pp. 115-126 https://doi.org/10.1023/A:1010087311616
  4. Medved, A., Dorman, F., Kaufman, S. L. and Pocher, A., 2000, 'A New Corona-based Charger for Aerosol Particles,' J. Aerosol Sci., Vol. 31, Suppl 1, pp. 616-617 https://doi.org/10.1016/S0021-8502(00)90625-6
  5. Sierra, A. H., Alguacil, F. J. and Alonso, M., 2003, 'Unipolar Charging of Nanometer Aerosol Particles in a Corona Ionizer,' J. Aerosol Sci., Vol. 34, pp. 733-745 https://doi.org/10.1016/S0021-8502(03)00033-8
  6. Kruis, F. E. and Fissan, H., 2001, 'Nanoparticle Charging in a Twin Hewitt Charger,' J. Nanopart. Res., Vol. 3, pp. 39-50 https://doi.org/10.1023/A:1011425816983
  7. Jeong, H. J. and Kim, S. S., 2001, 'Condensational Growth of Particles Through Expansion in a Capillary Tube,' Ph Thesis, KAIST
  8. Park, S. H. and Lee, K. W., 2000, 'Condensational Growth of Polydisperse Aerosol for the Entire Particle Size Range,' Aerosol Sci. Tech., Vol. 33, pp. 222-227 https://doi.org/10.1080/027868200416213
  9. Park, S. H., Lee, K. W., Shimada, M. and Okuyama, K., 2002, 'Change in Particle Size Distribution of Aerosol Undergoing Condensational Growth: Alternative Analytical Solution for the Low Knudsen Number Regime,' J. Aerosol Sci., Vol. 33, pp. 1297-1307 https://doi.org/10.1016/S0021-8502(02)00070-8
  10. Choi, Y. J. and Kim, S. S., 2004, 'Unipolar Charging of Submicron Particles Using the Condensation and Evaporation Method,' The 5th Korean conference on aerosol and particle technology, pp.209-210
  11. Suh, J. S., Han, B. W., Kim, D. S. and Choi, M. S., 2005, 'A Method for Enhanced Charging of Nano Particles via Condensation Magnification,' J. Aerosol Sci., Article in press https://doi.org/10.1016/j.jaerosci.2005.02.001
  12. Friedlander, S. K., 2000, Smoke, Dust, and Haze-Fundamentals of Aerosol Dynamics, Oxford Press