• Title, Summary, Keyword: field collection

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A Basic Study on Developing an Electrocharged Scrubber (전기하전식 세정집진장치 개발에 관한 기초 연구)

  • 김종호
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.1
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    • pp.33-39
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    • 1999
  • This study has been performed to develop an efficient electrocharged scrubber. To improve collection efficiency of the scrubber, electric-charger was installed at the forefront of the packed crossflow scrubbers, and an experiment of changing discharge electrode shape and fluctuating electric field strength was undertaken. After using a light-oil boiler for generation of particles in the about 80% weight of submicron size particles was exhausted. Collection characteristics of the electrocharged scrubber were similar to those of two-stage electrostatic precipitator. In this study the collection efficiency of submicron size particles has been much improved, compared with the previous ones. In an experiment of changing discharge electrode and electric field strength, a needle-spike shape wire electrode showed a higher collection efficiency than round shape wire. The collection efficiency becomes increased with an increase of electric field strength.

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Effects of Electrohydrodynamic Flow and Turbulent Diffusion on Collection Efficiency of an Electrostatic Precipitator with Cavity Walls

  • Park, Seok-Joo;Park, Young-Ok;Kim, Sang-Soo;McMurry, Peter H.
    • Proceedings of the KSME Conference
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    • pp.97-103
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    • 2001
  • The effects of the electrohydrodynamic (EHD) flow and turbulent diffusion on the collection efficiency of a model ESP composed of the plates with a cavity were studied through numerical computation. The electric field and ion space charge density were calculated by the Poisson equation of the electrical potential and the current continuity equation. The EHD flow field was solved by the continuity and momentum equations of the gas phase including the electrical body force induced by the movement of ions under the electric field. The RNG $k-{\varepsilon}$ model was used to analyze the turbulent flow. The particle concentration distribution was calculated from the convective diffusion equation of the particle phase. As the ion space charge increased, the particulate collection efficiency increased because the electrical potential increased over the entire domain in the ESP. The collection efficiency decreased and then increased, i.e. had a minimum value, as the EHD circulating flow became stronger when the electrical migration velocity of the charged particle was low. However, the collection efficiency decreased with the stronger EHD flow when the electrical migration of the particle was higher relatively. The collection efficiency of the model ESP increased as the turbulent diffusivity of the particle increased when the electrical migration velocity of the particle was low. However, the collection efficiency decreased for increasing the turbulent diffusivity when the electrical migration of the particle was higher relatively.

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Effect of Secondary Flows on the Particle Collection Efficiency in Single Stage Electrostatic Precipitator (1단 전기 집진기에서 2차 유동이 집진 효율에 미치는 영향)

  • Lee, Jae-Bok;Bae, Gwi-Nam;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.2
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    • pp.251-259
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    • 2000
  • The ionic wind formed in a nonuniform electric field has been recognized to have a significant effect on particle collection in an electrostatic precipitator(ESP). Under normal operating conditions the effect of ionic wind is not pronounced. However, as the flow velocity becomes smaller, the ionic wind becomes pronounced and induces secondary flow, which has a significant influence on the flow field and the particle collecting efficiency. In this paper, experiments for investigating the effect of secondary flow on collection efficiencies were carried out by changing the flow velocities in 0.2-0.7m/s and the applied voltages in 9-11kV/cm. The particle size distributions and concentrations are measured by DMA and CNC. To analyze the experimental results, numerical analysis of electric filed in ESP was carried out. It shows that particle collection is influenced by two independent dimensionless numbers, $Re_{ehd}\;and\;Re_{flow}$ not by $N_{ehd}$ alone. When $Re_{flow}$, decreases for constant $Re_{ehd}$, the secondary flow prohibits the particle collection. But when $Re_{ehd}$ increases for constant $Re_{flow}$, it enhances the particle collection by driving the particles into the collection region.

Study on Electrohydrodynamic Analysis of Cylinder Type ESP (원통형 전기집진기의 전기유체역학적 해석에 관한 연구)

  • 조용수;여석준
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.3
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    • pp.243-254
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    • 1996
  • The main purpose of this study is to investigate the collection efficiency characteristics of a cylindrical ESP. To do that, it is necessary to analyze the electric field, gas flow field, and mechanism of particle movement by numerical simulation based on EHD model. For a gas flow field, Navier-Stokes equation involving the electric source term was solved by SIMPLE algorithm. In case of the electric field, the current continuity and electric field equations were solved by S.O.R. method. The analysis of particle movement was performed on the basis of PSI-CELL model from the Lagrangian viewpoint. The results showed that the influence on the gas flow field by the electric field is almost negligible in a cylindrical ESP. The particle drift velocity $V_P$ toward the collection surface is increased continuously by the electrostatic force due to the rise of particle charge as the particle is moving to the flow direction and the particle size becomes larger. The collection efficiency is to quitely higher with the increase of applied voltage for the same particle size, while becomes smaller as the inlet velocity is increased.

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A Study on Prediction of Collection Efficiency of Electrostatic Precipitator Using Eulerian Numerical Analysis (오일러리안 수치해석법을 이용한 전기집진기의 집진효율 예측에 관한 연구)

  • Park, Jeong-Ho;Chun, Chung-Hwan
    • Proceedings of the KSME Conference
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    • pp.618-623
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    • 2001
  • The transport of charged particles in electrostatic precipitator is investigated by Eulerian numerical analysis. Collection efficiencies are calculated using various combinations of the assumptions about flow field, turbulent diffusivity and boundary condition at collecting electrode. The characteristics of calculated collection efficiencies are compared with the trends of published experimental results. It is found that the collection efficiency for the case using nonuniform turbulent flow field, nonuniform turbulent diffusivity and zero concentration boundary condition at collecting electrode is the most suitable for the prediction of collection efficiency of electrostatic precipitator.

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Development of Expert-System for Municipal Solid Waste Collection and Transportation (생활 폐기물 수집.수송 관리를 위한 Expert-System 개발)

  • Kang, Dong-Gu;Ryu, Don-Sik;Lee, Hae-Seung;Lee, Chan-Ki
    • Journal of the Korean Society of Hazard Mitigation
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    • v.1 no.1
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    • pp.91-102
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    • 2001
  • This study aims to provide a program for the municipal solid waste collection and transportation management through data consolidation and field research of the materials about waste collection and transportation in a small city. The field research was conducted in the collection zone of the housing, apartment and business section within C city area. As a result, the main factor of collection and transportation plan required at the waste collection and transportation process and the central mean applying at the small city were calculated. The process that systemize the waste collection and transportation step and the expert system were constructed. In conclusion, the developed management system of the municipal solid waste collection and transportation can be wildly used by adding the data of other zone.

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Development of Efficient System for Collection-Analysis-Application of Information Using System for Technology and Information in the Field of RI-Biomics (RI-Biomics 기술정보시스템을 활용한 효율적인 정보 수집-분석-활용 체계 수립에 관한 연구)

  • Jang, Sol-Ah;Kim, Joo Yeon;Park, Tai-Jin
    • Journal of Radiation Industry
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    • v.9 no.3
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    • pp.161-166
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    • 2015
  • RI-Biomics is the new radiation fusion technology of which, such as the characteristics of radioisotope, is applied to the biomics. In order to sharing and overall analysis of data between the institutions through total management of information in the field of RI-Biomics, RI-Biomics Information portal 'RIBio-Info' was constructed by KARA (Korean Association for Radiation Application) in February 2015. For systematic operation of this 'RIBio-Info' system, it is required to develop system of collection-analysis-application of information. So, in this paper, we summarized development of document forms at each processes of collection-analysis-application of information and systematization of collection methods of information, establishment of characteristically analysis methods of reports such as issue paper, policy report, global market report and watch report. Therefore, these are expected to improving the practical applicability in this field through the vitalization of technology development of users by achieving the circular structure of collectionanalysis-application of information.

Filtration Performance of Fibrous Air Filter under External Electric Field using Insulated Electrodes (외부전기장 적용 섬유상 에어필터의 절연 전극 사용에 따른 여과특성)

  • Ji, Sung-Mi;Sohn, Jong-Ryeul;Park, Hyun-Seol
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.6
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    • pp.675-687
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    • 2012
  • Applying an external electric field across air filter media is one of methods to improve the filtration performance. Metal wire meshes have been commonly used as electrodes situated on both sides of a thick filter pad. For a thin filter medium a short circuit, known as the biggest drawback for applying an external electric field to air filter, can occur at the closest point between electrodes. In this study several types of insulated meshes were prepared by coating #50 meshes with a dielectric material, Nylon 66, and the filtration property of air filter was evaluated at the presence of external electric field using those insulated meshes as electrodes and compared with that of filters using bared meshes. The collection efficiency of tested filter was increased from 78% to 95% for singly charged 100 nm particles by application of external electric field. As a result, there was no significant difference in collection efficiency between filters with insulated and bared electrodes. Similar results could be also seen from the tests using polydisperse particles. Finally, through this study, we found that the insulation of mesh electrodes doesn't affect the filtration performance of fibrous air filter under external electric field.

A remote long-term and high-frequency wind measurement system: design, comparison and field testing

  • Zhao, Ning;Huang, Guoqing;Liu, Ruili;Peng, Liuliu
    • Wind and Structures
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    • v.31 no.1
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    • pp.21-29
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    • 2020
  • The wind field measurement of severe winds such as hurricanes (or typhoons), thunderstorm downbursts and other gales is important issue in wind engineering community, both for the construction and health monitoring of the wind-sensitive structures. Although several wireless data transmission systems have been available for the wind field measurement, most of them are not specially designed for the wind data measurement in structural wind engineering. Therefore, the field collection is still dominant in the field of structural wind engineering at present, especially for the measurement of the long-term and high-frequency wind speed data. In this study, for remote wind field measurement, a novel wireless long-term and high-frequency wind data acquisition system with the functions such as remote control and data compression is developed. The system structure and the collector are firstly presented. Subsequently, main functions of the collector are introduced. Also novel functions of the system and the comparison with existing systems are presented. Furthermore, the performance of this system is evaluated. In addition to as the wireless transmission for wind data and hardware integration for the collector, the developed system possesses a few novel features, such as the modification of wind data collection parameters by the remote control, the remarkable data compression before the data wireless transmission and monitoring the data collection by the cell phone application. It can be expected that this system would have wide applications in wind, meteorological and other communities.

Numerical analysis of collection performance for electro-cyclone (전기싸이클론의 집진 성능 해석)

  • 김완수;강윤호;이진원
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.6
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    • pp.702-713
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    • 1998
  • The characteristics of flow and particle collection for an electrocyclone with a central wire inside a high efficiency Stairmand cyclone was numerically analysed. Turbulent flow field was modeled by the Reynolds stress model and solved with an FVM code FLUENT. Particle motion and in-situ charging were simultaneously solved by a Lagrangian integration with time. The flow field obtained was in good agreement with experiments in the outer region. The characteristics of collection enhancement due to electric force were well manifested and well explained based on first principles. The effect of the in-situ charging process was very similar to the case of a simplified assumption of saturated charging, and the effect of the hopper was proved negligible.

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