• Title/Summary/Keyword: Electrostatic effect

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Spraying Performance Evaluation of Spraying Nozzle Using Electrostatic Effect (정전효과를 이용한 분무노즐의 분무성능 평가)

  • 조성인;이동훈
    • Journal of Biosystems Engineering
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    • v.21 no.4
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    • pp.456-466
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    • 1996
  • Electrostatic spraying is needed for today's sustainable farming. An electrostatic spraying nozzle was developed and its spraying performance was evaluated. High voltages of 15㎸, 20㎸, and 25㎸ were supplied for the electrostatic electrode. Artificial and real apple targets were used for the spraying experiments. Insulated material was used around the electrode to protect the loss of electrostatic effect. Three angles (0, 45, 90 degree) of spraying direction were used for the spraying test. The performance of electrostatic spraying was improved from 204.5% upto 429.2% on the apple targets.

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Effects of the Block Arrangement on the Collection Efficiency in the Two-Stage Electrostatic Precipitator with Charging Plate (평판형 방전판을 갖는 2단식 전기집진기의 집진판 블록배열이 집진효율에 미치는 영향)

  • 박성호;박청연;김태권
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.6
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    • pp.641-652
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    • 2000
  • The effect of block arrangement has been investigated on the particle deposition in the specified collecting cell of two-stage electrostatic precipitator by numerical analysis. Recirculation zone existed at the downstream of the block in the collecting cell, and the particles entering the recirculation zone were deposited on the collecting plate. Particle trajectory and deposition had considerably different phenomenon according to electrostatic and inertial effect, which depended on inlet mean velocity, electrostatic number, and particle diameter in the collecting cell. The total collection efficiency reached a minimum value through an interaction of electrostatic and inertial effect. In the computational domain, total collection efficiency for the case of two blocks in the computational domain was more than that of one block at the relative small electrostatic number. However as the block distance and inertial effect increased, the difference between the collection efficiency of two cases decreased. In the range of relatively small particle size total collection efficiency was always superior to particle collection efficiency that was predicted by Deutsch equation.

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Study of Size Effect on Electrostatic Colloid Micro Thruster (정전기장 콜로이드 마이크로 추진기관의 크기에 따른 영향에 대한 연구)

  • Yang Ji-Hye;Byun Do-Young
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.278-281
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    • 2005
  • This paper present a study of size effect on electrostatic colloid micro thruster. According to results about size effect experiments indicates that the proposed mechanism allows at less than 500 volt of operating voltage for the micro thruster.

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Solvent Effect on the Dynamics of Radical Ion Pair Separation

  • Han, Chul-Hee
    • Journal of Photoscience
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    • v.8 no.1
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    • pp.33-37
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    • 2001
  • Picosecond absorption spectroscopy has been employed in the study of the solvent dynamics of 1, 2, 4, 5-tetracyanobenzene/biphenyl derivative radical ion pairs, and the resulting rates of radical ion pair separation are faster in acetonitrile than in dichloromethane. In an effort to account quantitatively for such solvent effect on the rate of radical ion pair separation, an equation for the rate of radical ion pair separation is introduced, in which the rate depends exponentially on the electrostatic interaction energy in the radical ion pair. In our analysis of the types of electrostatic interaction energy based on the conducting spheres in dielectric continuum was chosen, and the rate equation employing this electrostatic energy provided information on the distance on the distance of radical ion pair separation and solvation energy of the radical ion pair, thereby providing quantitative explanation for the observed solvent effect on the rate of radical ion pair sepaaration.

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Comparison of Spray Characteristics between Conventional and Electrostatic Pressure-Swirl Nozzles

  • Laryea, G.N.;No, S.Y.
    • Journal of ILASS-Korea
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    • v.11 no.1
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    • pp.24-29
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    • 2006
  • Spray characteristics produced by conventional and electrostatic pressure-swirl nozzles for an oil burner have been studied, using kerosine as a test liquid. The charge injection mechanism is used to design the electrostatic nozzle, where specific charge density, breakup length, spray angle and mean diameter are measured and analyzed. Three nozzles with orifice diameters of 0.256, 0.308 and 0.333mm at injection pressures of 0.7, 0.9, 1.1 and 1.3 MPa are used in the study. In case of the electrostatic nozzle, voltages ranging from -5 to -12kV are applied. Comparison of the spray characteristics is made between the conventional and electrostatic nozzles. The results showed that, the electrostatic nozzle is superior to the conventional nozzle. This is due the effect of voltage on the liquid surface tension.

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Analysis on particle deposition onto a heated, horizontal free-standing wafer with electrostatic effect (정전효과가 있는 가열 수평웨이퍼로의 입자침착에 관한 해석)

  • Yoo, Kyung-Hoon;Oh, Myung-Do;Myong, Hyon-Kook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.10
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    • pp.1284-1293
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    • 1997
  • The electrostatic effect on particle deposition onto a heated, Horizontal free-standing wafer surface was investigated numerically. The deposition mechanisms considered were convection, Brownian and turbulent diffusion, sedimentation, thermophoresis and electrostatic force. The electric charge on particle needed to calculate the electrostatic migration velocity induced by the local electric field was assumed to be the Boltzmann equilibrium charge. The electrostatic forces acted upon the particle included the Coulombic, image, dielectrophoretic and dipole-dipole forces based on the assumption that the particle and wafer surface are conducting. The electric potential distribution needed to calculate the local electric field around the wafer was calculated from the Laplace equation. The averaged and local deposition velocities were obtained for a temperature difference of 0-10 K and an applied voltage of 0-1000 v.The numerical results were then compared with those of the present suggested approximate model and the available experimental data. The comparison showed relatively good agreement between them.

A Study on Electrostatic Discharging in Ultrapure and Electrolyzed Waters Using Kelvin's Thunderstorm Effect (캘빈방전 효과를 이용한 초순수 및 전해이온수의 정전기 방전 연구)

  • Kim, Hyung-won;Jung, Youn-won;Choi, In-sik;Choi, Byung-sun;Choi, Donghyeon;Ryoo, Kun-kul
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.1
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    • pp.5-11
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    • 2022
  • Despite the increasing importance of manufacturing and application R&D for ultrapure deionized water and electrolyzed ion water, various and systematic studies have not been conducted until now. In this study, the electrostatic discharge (ESD) behavior of electrolyzed ion water using a proton exchange membrane(PEM) was evaluated according to the type, flow rate, and bubble of electrolyzed ion water. In addition, by observing that Oxidation Reduction Potential (ORP) value returns to the unique value of electrolyzed ion water after electrostatic discharge, the possibility of two types of ions participating in electrostatic discharge ((H2O)n+ (assumed)) and ions for maintaining the characteristics of electrolyzed water could be inferred. In order to confirm the chemical structure and characteristics of the cations, in-depth research related to water molecular orbital energy or band gap should be followed.

An Operating Circuits Design for preventing Electrostatic Discharge in Liquid Crystal Displays

  • Jo, Jo-Yeon;Yi, Jun-Sin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.674-676
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    • 2008
  • An electrostatic discharge (ESD) or a noise supplied from the outside has an effect on communication between the timing controller (TCON) and the memory element (EEPROM) through the interface between the timing controller and the memory element in liquid crystal displays (LCD). Therefore, we must apply ESD protection methods to LCD operating circuits for a normal operation. Our ESD protection circuit is to prevent from bi-directional communication errors between TCON and EEPROM due to an electrostatic discharge (ESD).

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A Study on the Holding of LED Sapphire Substrate Using Alumina Electrostatic Chuck with Fine Electrode Pattern (미세 전극 패턴을 갖는 알루미나 정전척을 이용한 LED용 사파이어 기판 흡착 연구)

  • Kim, Hyung-Ju;Shin, Yong-Gun;Ahn, Ho-Kap;Kim, Dong-Won
    • Journal of the Korean institute of surface engineering
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    • v.44 no.4
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    • pp.165-171
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    • 2011
  • In this work, handling of sapphire substrate for LED by using an electrostatic chuck was studied. The electrostatic chuck consisted of alumina dielectric, which was doped with 1.2 wt% $TiO_2$. As the volume resistivity of alumina dielectric was decreased, the electrostatic force was increased by Johnsen-Rahbek effect. The narrower width and gap size of electrode led to the stronger electrostatic force. When alumina dielectric with $3.20{\times}10^{11}{\Omega}{\cdot}cm$ resistivity and 3 mm width/1.5 mm gap sized electrode was used, the strongest electrostatic force in this work was obtained, which value reached to ~14.46 gf/$cm^2$ at 2.5 kV for 4-inch sapphire substrate. This results show that alumina electrostatic chuck with low resistivity and fine electrode pattern is suitable for handling of sapphire substrate for LED.

A Study on the new method of electrostatic elimination in oil flowing pipe. (세관을 흐르는 절연유의 유동대전에 의한 대전전하의 제전방법에 관한 연구)

  • Minari, Kogane;Park, Jae-Yun;Lee, Duck-Chool;Hwang, Myung-Hwan
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.129-131
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    • 1990
  • When insulating oil is flowed through a pipe, the electrostatic charge in the oil will be increased. Using inflammability oil, an electrostatic phenomena which may cause significantly problems as explosion must be circumvented by some methods. In this paper we made a new electrode which was applied AC field to the flowing oil for reducing electrostatic charge. Before we developed the new method of an electrostatic elimination, the electrification experiment was performed by using the same electrode which was supplied DC voltage to realize electrified conditions. As a result of this study, the effect of the electrostatic elimination could be observed.

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