• Title/Summary/Keyword: 임팩터

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Design and Performance Evaluation of a Portable 3-Stage Electrical Low Pressure Impactor(P-ELI) for Measurements of Submicron Aerosol (미세입자 측정용 간이형 3단 전기적 저압 임펙터의 설계 및 성능평가)

  • Cho, Myung-Hoon;Ji, Jun-Ho;Park, Dong-Ho;Bae, Gwi-Nam;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.7
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    • pp.826-833
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    • 2004
  • Cascade impactors are widely used to collect size classified aerosol. A major disadvantage of this instrument is the required long sampling time. Electrical low pressure impactor has been developed to overcome this disadvantage and to achieve real-time measurements on the particle size distribution. The instrument consists primarily of a corona charger, low pressure cascade impactor and multi channel electrometer. We designed and evaluated the performance of a potable 3-stage low pressure impactor using an electrical method. For the calibration of the impactor, monodispersed particles were generated using evaporation-condensation method followed by electrostatic classification using a DMA(Differential Mobility Analyzer). The collection efficiency curves of the stages can be determined by analysing the fraction of particles collected by each stage.

Variations of Aerosol Size Distribution on Ambient Air (대기중 에어로졸 입경분포의 변화)

  • 김신도;안기석;김종호;김태식
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.83-84
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    • 1999
  • 시정악화나 광화학 스모그를 비롯하여 지구 온난화에 부유 입자상 물질이 미치는 영향 등을 파악하기 위해선 중량농도, 화학적 성분분석 등과 함께 그 입경별 크기 분포도 반드시 고려되어야만 한다. 입경분포 측정을 위하여 다단식 임팩터(Cascade Impactor)나 광학입자계수기(OPC, Optical Particle Counter), Aerosizer, SMPS (Scanning Mobility Particle Sizer), EAA(Electrical Aerosol Analyzer) 등 이주로 사용되고 있다.(중략)

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Numerical Investigation of Collection Efficiency of Virtual Impactor with Electro-Aerodynamic Lens (전기-공기역학적 렌즈를 이용한 가상임팩터 포집효율에 관한 수치적 연구)

  • Zahir, Muhammad Zeeshan;Yook, Se-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.7
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    • pp.63-70
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    • 2019
  • An electro-aerodynamic lens for improving the performance of virtual impactor has been proposed in this study. ANSYS FLUENT Release 16.1 was used for numerical analysis of virtual impactor with and without the electro-aerodynamic lens, used to collimate the incoming aerosol particles into a particle beam before injecting the particles into the virtual impactor. Particles supplied to the electro-aerodynamic lens were assumed to be highly charged. By using an aerodynamic lens before the virtual impactor, without any electrostatic effect, it was found that the cut-off diameter of the virtual impactor was reduced from $4.2{\mu}m$ to $0.68{\mu}m$ and that the fine particle contamination problem became more serious. However, by employing the combined electrostatic and aerodynamic effects, that is, by applying electric voltage potential to the electro-aerodynamic lens, the cut-off diameter was found to be further reduced to $0.45{\mu}m$ and the fine particle contamination was eliminated.

Effect of Particle Clogging in Orifices on the Particle Collection Efficiency of a Micro-Orifice Impactor (노즐 막힘이 미세 오리피스형 다단 임팩터의 입자 채취 성능에 미치는 영향)

  • Ji, Jun-Ho;Bae, Gwi-Nam;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.2
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    • pp.197-205
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    • 2003
  • A cascade impactor is a multistage impaction device used to separate airborne particles into aerodynamic size classes. A micro-orifice impactor uses micro-orifice nozzles to extend the cut sizes of the lower stages to as small as 0.05 ${\mu}{\textrm}{m}$ in diameter without resorting to low pressures or creating excessive pressure drops across the impactor stages. In this work, the phenomenon of particle clogging in micro-orifice nozzles was experimentally investigated for a commercial micro-orifice uniform deposit impactor (MOUDI). It was observed, using an optical microscope, that the micro-orifice nozzles of the final stages were partially clogged due to particle deposition during the aerosol sampling. Therefore the pressure drops across the nozzles were higher than the nominal values given by the manufacturer. To examine the effect of particle clogging in micro-orifice nozzles, the particle collection efficiency of the MOUDI was evaluated using an electrical method for fine particles with diameters in the range of 0.1-0.6 ${\mu}{\textrm}{m}$. The monodisperse liquid dioctyl sebacate (DOS) particles were used as test aerosols. A faraday cage was employed to measure the low-level current of the charged particles upstream and downstream of each stage. It was found that the collection efficiency curves shifted to correspond to smaller orifice sizes, and the 50-% cutoff sizes were much smaller than those given by the manufacturer for the three stages with nozzles less than 400 ${\mu}{\textrm}{m}$ in diameter.

Performance Evaluation of the Faraday Cage for a Electrical Impactor (전기적 임팩터용 페러데이 케이지의 성능평가)

  • 지준호;배귀남;황정호;이규원
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2000.11a
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    • pp.117-118
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    • 2000
  • 대전 입자의 거동은 입자의 제어 측면뿐만 아니라 입자의 측정에서 중요한 요소 중 하나이다. 특히, 입자를 실시간으로 측정하는 경우 입자의 대전량을 정밀하고 정확하게 측정하는 것은 측정 대상이 심하게 변할 때 매우 중요하다. 입자의 전기적 특성(대전량)을 이용하여 입경분포를 측정하는 장비로는 EAA(electrical aerosol analyzer), SMPS(scanning mobility particle sizer), ELPI(electrical low pressure impactor) 등이 있다. (중략)

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