• Title/Summary/Keyword: Electrostatic discharge

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Characteristics of long-term operated Electrostatic airclean filter for air-conditioner (장시간사용(長時間使用)한 공조용(空調用) 전기집진(電氣集塵)필터의 특성(特性))

  • Hong, Young-Ki;Kang, Kwang-Ok;Lee, Sung-Hwa;Son, Sang-Cheol
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.453-455
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    • 1995
  • In electrostatic airclean filter, the collection efficiency defends on particle charge in the ionizer section. The effect of electrostatic airclean filter condition (deposition of dust, variation of corona discharge current) on corona discharge characteristics was well studied. However, it seems not to be studied on corona discharge characteristics of electrostatic airclean filter respect to contaminated electrode which is caused by practical use. In this paper, Long-term(60days) effects are studied experimentally by two methods. The one is ozone concentration, the other is collection efficiency. Generation of ozone level was increased but collection efficiency was slightly reduced in long-term used electrostatic airclean filter.

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Experimental Study on the Discharge Electrode of A Two-Stage Electrostatic Air Cleaner (2단 평행판 전기집진기의 방전부 특성 실험)

  • Kim, I.S.;Lee, J.O.;Kim, Y.J.;Choi, H.O.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.5 no.1
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    • pp.27-34
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    • 1993
  • The two-stage electrostatic air cleaner is a particle control device that uses electrical forces to move particles in the flowing gas stream onto collector plates. Despite a general understanding of electrostatic air cleaner operation and their successful use in industry, many questions regarding flow, electric fields and particle collection have remained unanswered. In this paper, an experimental investigation for designing the discharge electrode, including ionizer wire diameter, plate length and wire-to-plate spacing, is carried out. The electrical conditions, namely the electric field intensity, the space current and the particle charge intensity, in wire-plate electrostatic air cleaner are reported and examined.

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Characteristics of the Reduction of Fine Particles in an Indoor Air Cleaner Using Electrostatic Precipitation Technique (전기집진기형 공기청정기의 미세 먼지 저감 특성에 관한 연구)

  • Mok, Young-Sun;Lee, Ho-Won
    • Journal of the Korean Society of Industry Convergence
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    • v.7 no.1
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    • pp.115-120
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    • 2004
  • An indoor air cleaner consisting of a dielectric barrier discharge system and an electrostatic precipitator (ESP) was experimentally investigated. The function of the dielectric barrier discharge is to precharge particles by producing nonthermal plasma before indoor air enters ESP, leading to an enhancement in dust collection efficiency. The dependence of particle size distribution on the plasma discharge was examined to understand the mechanism of the particle precharging. The plasma discharge was found to increase the electrical force of the particles, rather than agglomerate them. Coarse particles in the range of 0.5 to $5.0{\mu}m$ were observed to be easily collected by this indoor air cleaner, and the present study laid emphasis on the removal of fine particles of $0.3{\mu}m$. The collection efficiency of the fine particles was largely enhanced by the plasma discharge.

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A Study on Electrostatic Charging Characteristics in Vehicle Fuel Systems (차량 연료시스템에서의 정전기 축적특성 연구)

  • Seo, Joon-Ho;Na, Byung-Chul;Kim, Jin-Young
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2157-2162
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    • 2004
  • As the friction between two mated materials generates electrostatic voltage, vehicles especially in the cold climate has been accumulated an electrostatic voltage by the reason of fuel flow in the fuel line, air flows out side of vehicle, etc. In this study, investigations of electrostatic discharge characteristics has been carried out in the fuel systems of gasoline engines depending on the environment temperature. For the experiment, conventional fuel filters(paint coated steel case) and specially made testing equipment are prepared. The experimental results shows, an accumulation speed of electrostatic voltage depends on the environmental temperature and new methods of testing procedures are required compare to SAE standards.

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Experiental Study on the Electrostatic Discharge in the HDD Spindle System Using Fluid Dynamic Bearings (유체동압베어링을 사용하는 하드 디스크 드라이브 스핀들 시스템에서 발생하는 정전기 방전에 관한 실험적 연구)

  • Kang, Min-Gu;Jang, Gun-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.318-323
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    • 2005
  • This paper introduces the mechanism of the ESD (Electrostatic discharge) in the HDD spindle system using FDBs (Fluid Dynamic Bearings). When a HDD (Hard Disk Drive) spindle system is rotating, triboelectric charging occurs in the FDBs through the friction of the lubricant between the rotating shaft and stationary sleeve. And this electrostatic charge is accumulated in the rotating part of the HDD spindle system because it is insulated from the ground by the lubricant. This research shows experimentally that the behavior of electric charge and discharge in the FDB spindle system is the same as that of a capacitor. It also measures the electrostatic charge and discharge of the FDB spindle system due to the chanse of humidity, supporting load and motor speed. This research shows that the control of ESD is required in the HDD spindle system using FDBs, because the electrostatic charge accumulated in the FDB spindle system may cause the breakdown damage of the GMR head and data loss consequently.

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Investigation of Characteristics of Electrostatic Bag Filter with Discharge Electrode Shapes and Filter Properties (방전극 형상 및 여과재에 따른 정전 여과집진장치특성에 관한 연구)

  • 김정일;여석준
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.3
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    • pp.237-250
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    • 1998
  • In this study, the characteristics of electrostatic bag filter to overcome the main problems such as the high pressure drop and low collection efficiency for submicron particles are investigated with the experimental parameters. Especially, the experiment is carried out focusing on collection efficiency and pressure drop change mechanism as a function of discharge electrode shapes and filter properties, including the applied voltages, filtration velocities and particle concentrations, etc . Results show that the collection efficiency is improved over 30% for the fine particle below 1 pm and pressure drop reduction ratio (PDRR) increases in the following order 4 mm screwy > 4 mm square > 4mm round discharge electrodes . For the filter properties, Nomex is more effective than PE under the influence of electrostatic force. Applying 30 kV for a screwy discharge electrode, higher overall collection efficiency is maintained in spite of the increment of filtration velocity over four times (8 m/min) in comparison with that of 2 m/min and PDRR are highly shown over 80o1o with various filtration velocities, 5, 8, 11 m/min.

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Dynamic analysis of charged human body electrostatic discharge - comparison with quasi-static discharge (대전인체의 정전기 방전에 대한 동적해석 - 준정적해석과의 비교)

  • 이종호;김두현;김상철;김상렬
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 1998.05a
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    • pp.257-262
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    • 1998
  • In order to understand the characteristics of electrostatic discharge (ESD) by a charged human body, a dynamic analysis method based on RCL circuit and a quasi-static analysis method based on two-body model are introduced. In this paper, these methods calculate waveforms, discharge energy and potential difference to analyze the ESD phenomena from given initial conditions and geometry. Results are compared and discussed.

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A Study of Measurement of Minimum Ignition Energy for Pine Tree Dust on Electrostatic Discharges (정전기 방전시의 소나무목분의 최소착화에너지 측정에 관한 연구)

  • 이동훈;박한석
    • Journal of the Korean Society of Safety
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    • v.13 no.3
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    • pp.74-79
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    • 1998
  • To establish measuring method for minimum ignition energy of explosive powders caused by electrostatic discharge, A measuring method(Hartman) using a very small quantity of pine tree testing powder was proposed, and the influence of discharge current limiting resistance connected in series into a capacitive discharge circuit on ignition energies of explosive powders was investigated. As a result the minimum ignition energy was 42.25mJ when discharge current limiting resistance 300 $k\Omega$.

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Electrostatic discharge simulation of tunneling magnetoresistance devices (터널링 자기저항 소자의 정전기 방전 시뮬레이션)

  • Park, S.Y.;Choi, Y.B.;Jo, S.C.
    • Journal of the Korean Magnetics Society
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    • v.12 no.5
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    • pp.168-173
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    • 2002
  • Electrostatic discharge characteristics were studied by connecting human body model (HBM) with tunneling magnetoresistance (TMR) device in this research. TMR samples were converted into electrical equivalent circuit with HBM and it was simulated utilizing PSPICE. Discharge characteristics were observed by changing the component values of the junction model in this equivalent circuit. The results show that resistance and capacitance of the TMR junction were determinative components that dominate the sensitivity of the electrostatic discharge(ESD). Reducing the resistance oi the junction area and lead line is more profitable to increase the recording density rather than increasing the capacitance to improve the endurance for ESD events. Endurance at DC state was performed by checking breakdown and failure voltages for applied DC voltage. HBM voltage that a TMR device could endure was estimated when the DC failure voltage was regarded as the HBM failure voltage.

Experimental Study on Electrostatic Hazards of Powder in Fluidized Bed (유동층 건조설비에 있어서 분진의 정전기 위험성에 관한 실험적 연구)

  • Moon, Kyoon-Tae;Chung, Jae-Hee;Choi, Kwang-Seok
    • Journal of the Korean Society of Safety
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    • v.25 no.4
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    • pp.19-24
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    • 2010
  • A large amount of electrostatic charges is often generated on polymer powders in fluidized bed and thereby may lead to electrostatic problems. In this study, to evaluate electrostatic hazards of powder in fluidized bed, the electric field(E[v/m]) and the charge amount(q[c/g]) during fluidizing were monitored. We also investigated the Minimum Ignition Energy(MIE [J]) of sample powder used in fluidized bed with the Hartman vertical-tube apparatus. The batch-type fluidized bed system and 2kg as Polypropylene(PP) resin powders were used in the experiments. The following results were obtained: (1) Even when a safe margin of several times was considered, the values of E obtained with PP powder in this paper did not exceed 3 to 5kV/cm, at which an incendiary electrostatic discharge could occur. (2) the ave. q was -0.26${\mu}$C/g during fluidizing. This value was high enough to cause electrostatic agglomeration and adhesion. (3) the entrained PP powder in upper column due to fluidizing could be ignited by electrostatic discharges of 71mJ.