• 제목/요약/키워드: polydispersed aerosol

검색결과 6건 처리시간 0.024초

입자층 에어로졸여과의 과도거동에 관한 실험연구 : 압력강하에 대한 입자 퇴적의 영향 (An Experimental Study on Transient Behavior of Granular Aerosol Filtration : Effect of Particle Deposition on Pressure Drop)

  • 정용원
    • 한국대기환경학회지
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    • 제13권3호
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    • pp.193-205
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    • 1997
  • Experiments on granular filtration of polydispersed aerosols were conducted to determine the changes in pressure drop necessary to maintain a given gas flow rate as filter becomes clogged with deposited particles. Among the various variables which affect the increase in the pressure drop during the filtration, the most important one was found to be the size of the deposited aerosol particles. It was shown that for a given extent of the total deposition, the extent of increase in pressure drop increases with the decrease of the deposited aerosol size. For the general case where the deposited particles have different sizes, a procedure was proposed for correlating and predicting experimental results on pressure drop. This procedure was found applicable to bidispersed aerosols and polydispersed aerosols.

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Changes in the Ångstrom Exponent during Aerosol Coagulation and Condensation

  • Jung, Chang H.;Lee, Ji Yi;Kim, Yong P.
    • Asian Journal of Atmospheric Environment
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    • 제6권4호
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    • pp.304-313
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    • 2012
  • In this study, the ${\AA}$ngstrom exponent for polydispersed aerosol during dynamic processes was investigated. Log-normal aerosol size distribution was assumed, and a sensitivity analysis of the ${\AA}$ngstrom exponent with regards the coagulation and condensation process was performed. The ${\AA}$ngstrom exponent is expected to decrease because of the particle growth due to coagulation and condensation. However, it is difficult to quantify the degree of change. In order to understand quantitatively the change in the ${\AA}$ngstrom exponent during coagulation and condensation, different real and imaginary parts of the refractive index were considered. The results show that the ${\AA}$ngstrom exponent is sensitive to changes in size distribution and refractive index. The total number concentration decreases and the geometric mean diameter of aerosols increase during coagulation. On the while, the geometric standard deviation approaches monodispersed size distribution during the condensation process, and this change in size distribution affects the ${\AA}$ngstrom exponent. The degree of change in the ${\AA}$ngstrom exponent depends on the refractive index and initial size distribution, and the size parameter changes with the ${\AA}$ngstrom exponent for a given refractive index or chemical composition; this indicates that the size distribution plays an important role in determining the ${\AA}$ngstrom exponent as well as the chemical composition. Subsequently, this study shows how the ${\AA}$ngstrom exponent changes quantitatively during the aerosol dynamics processes for a log-normal aerosol size distribution for different refractive indices; the results showed good agreement with the results for simple analytic size distribution solutions.

모멘트 방법을 이용한 전기집진기의 집진 효율 (Collection Efficiency of Electrostatic Precipitator using Moment Method)

  • 정창훈;이규원
    • 한국대기환경학회지
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    • 제18권5호
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    • pp.345-353
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    • 2002
  • A study of polydispersed aerosol dynamics by Electrostatic Precipitator (ESP) was carried out. The log-normal particle size distribution was assumed and moment method was considered. In order to apply moment method in Deutsch-Anderson equation, Cunningham slip correction factor and Cochet's charge equation were simplified for certain range of particle size. The three parameters, which explain the particle size distribution, such as total number concentration, geometric mean diameter, and geometric standard deviation were considered to derive the analytic solution. The obtained solution was compared with available numerical results (Bai et al., 1995). The comparison of the numerical and analytic results showed a good agreement.