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

The Korean Society of Mechanical Engineers (대한기계학회)
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Nano Particle Charging Characteristics of Aerosol Charge Neutralizers

에어로졸 중화기의 나노 입자 하전 특성

  • 지준호 (연세대학교 나노과학기술연구단) ;
  • 배귀남 (한국과학기술연구원 지구환경연구센터) ;
  • 황정호 (연세대학교 기계공학과)
  • Published : 2003.10.01
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Abstract

Aerosol charge neutralizers with various radioactive sources have been used to apply an equilibrium charge distribution to aerosols of unknown charge distribution. However, the performance of aerosol charge neutralizers is not well known, especially for highly charged particles. Measurements of highly charged particles are needed in air cleaning devices, e.g. electrostatic precipitator, bag filter with a pre-charger, and electrical cyclone. In this study, the particle charging characteristics of two different aerosol charge neutralizers were experimentally investigated for singly charged monodisperse particles and highly charged polydisperse particles. One has radioactive source of $^{85}$ Kr (beta source, 2 mCi) and the other has $^{210}$ Po (alpha source, 0,5 mCi). The air flow rate passing through each aerosol charge neutralizer was changed from 0.2 to 2.5 L/min. The results show that the charge distribution of singly charged monodisperse particles passing through the $^{85}$ Kr aerosol charge neutralizer is well agreed with the Boltzmann equilibrium charge distribution at an air flow rate of 0.3 L/min, However, it deviates from the equilibrium charge distribution when the air flow rates are 0.6, 1,0, and 1,5 L/min, On the other hands, the effect of air flow rate is insignificant for the $^{210}$ Po aerosol charge neutralizer. The non-equilibrium character in charge distribution of highly charged polydisperse particles passing through the $^{85}$ Kr aerosol charge neutralizer greatly depends on the air flow rate, however it is insensitive to the air flow rate for the $^{210}$ Po aerosol charge neutralizer.

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References

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