• Title, Summary, Keyword: Corona Discharge

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Experimental Study on the Effect of Plasma Reactor Type on Corona Discharge and NO-NO2 Conversion Characteristics (플라즈마 반응기구조에 따른 코로나방전 및 NO-NO$_2$ 전환특성에 관한 실험적 연구)

  • 박용성;전광민
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.6
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    • pp.65-71
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    • 2002
  • Characteristics of corona discharge of the different types of the plasma reactors which are cone-hole and cone-plate is investigated experimentally. The discharge starts at lower voltage for the cathode corona than the anode corona and spark occurs at higher voltage for the cathode corona. And the cathode corona makes more stable discharge than the anode corona. The effect of the base gas in corona discharge for different O$_2$/N$_2$ concentrations is related with the gas molecular weight. The discharge for the smaller molecular weight gas occurs easier than for the high molecular weight gas. The discharge current decreases with the increase of oxygen concentration and it increases more sharply for anode corona than for cathode corona as discharge voltage increases after corona onset voltage. NO-NO$_2$ conversion increases with the energy density of corona discharge and the addition of O$_2$ in a base N$_2$ gas.

Corona Discharge and Ozone Generation Characteristics of a Slit Dielectric Barrier Discharge Type Plasma Reactor with a Third Electrode (3전극이 부설된 틈새 장벽방전형 플라즈마장치의 코로나 방전 및 오존발생 특성)

  • Moon, Jae-Duk;Jung, Jae-Seung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.3
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    • pp.583-587
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    • 2007
  • Corona discharge and ozone generation characteristics of a slit dielectric barrier discharge type wire-plate plasma reactor with a third electrode have been investigated. When a third electrode is installed on a slit of the slit barrier, where an intense corona discharge occurs, it is found that a significantly increased ozone output could be obtained. This, however, indicates that the third electrode can activate the corona discharges both of the discharge wire and the slit of the slit barrier in the plasma reactor. As a result, a thin stainless wire, used as the third electrode has a strong effect to influence the corona discharge of the slit and corona wire, especially to the negative corona discharge. Higher amounts of the output ozone and ozone yield, about 1.27 and 1.29 times for the negative corona discharge, can be obtained with the third electrode, which reveals the effectiveness of the third electrode.

ORGANIC POLLUTANTS DEGRADATION USING PULSELESS CORONA DISCHARGE: APPLICATION IN ULTRAPURE WATER PRODUCTION

  • Shin, Won-Tae;Sung, Nak-Chang
    • Environmental Engineering Research
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    • v.10 no.3
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    • pp.144-154
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    • 2005
  • The use of ozone gained acceptance in the production of ultrapure water because of its powerful oxidizing ability. Ozone is currently used to deactivate microorganisms and remove organic contaminants. However, interest also exists in using radical species, which arc stronger oxidants than ozone, in such processes. One means of producing radical species is by corona discharge. This work investigates the use of a novel pulseless corona-discharge system for the removal of organic substances in ultrapure water production. The method combines corona discharge with electrohydrodynamic spraying of oxygen, forming microbubbles. Experimental results show that pulseless corona discharge effectively removes organics, such as phenol and methylene blue, in deionized water. The corona-discharge method is demonstrated to be comparable to the direct use of ozone at a high-applied voltage. The results also show that a minimum applied voltage exists for operation of the corona-discharge method. In this work, the minimum applied voltage is approximately 4.5 kV. The kinetic rate or phenol degradation in the reactor is modeled. Modeling results show that the dominant species of the pulseless corona-discharge reactor are hydroxyl radical and aqueous electron. Several radical species produced in the pulseless corona-discharge process are identified experimentally. The. major species are hydroxyl radical, atomic hydrogen species, and ozone.

Electrohydrodynamic Characteristics of AC Corona Discharge for the Frequency (교류 코로나 방전시 주파수 변화에 따른 전기유체역학적 특성)

  • Jung, Jae-Seung;Kim, Jin-Gyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.12
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    • pp.87-92
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    • 2012
  • In this paper, EHD(electrohydrodynamics) characteristics of AC corona discharge for the various frequency was investigated. Ionic wind velocity is controlled by the frequency of applied ac high voltage, and maximum velocity of the ionic wind is obtained at 1.2kHz. Maximum velocity are 1.90 m/s by metal corona electrode and 2.72m/s by wet porous corona electrode, These attain 91~99% of the maximum velocity in the DC corona discharge by adjusting the frequency through the experiments. In this paper, wet porous corona electrode has high possibility of cooling methode because a AC corona discharge using wet porous corona electrode is able to eject more water droplets than DC corona discharge.

Effective Ionic Wind Generation Utilizing a Cylindrical Corona Discharge Electrode (금속관형 코로나 방전극을 적용한 효과적인 이온풍 발생)

  • Jung, Jae-Seung;Moon, Jae-Duk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.3
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    • pp.599-603
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    • 2010
  • A point-mesh type corona system has been well used as a ionic wind blower. However this type corona system suffers from its lower ionic wind generation, because of its lower on-set and breakdown voltages of its very sharp needle point corona electrode. This means that the point corona electrode must act both as an effective ion-generator and a very higher electric field producer in the discharge airgap in order to generate higher ionic wind velocity. In this paper, a cylinder-mesh type discharge system as a ionic wind generator is proposed and investigated. The cylindrical corona electrode can produce many ions from its sharpened edge, and the corona on-set and breakdown voltages are very higher than those of the needle point corona electrode. As a result, this type cylindrical corona electrode might generate a higher ionic wind than the needle point corona electrode.

Characteristics of DC Surface Discharge for the Development of UV Camera (자외선 카메라 개발을 위한 직류 연면방전 특성)

  • Pang, Man-Sik;Choi, Jae-Hyeong;Kim, Woo-Jin;Kim, Young-Seok;Kim, Sang-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.5
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    • pp.98-103
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    • 2011
  • Recently, UV(ultra-violet rays) camera has attracted a great deal of interest from the view point of easy judgement in inspections and diagnoses of the safety of power equipment. Especilly, UV camera is applied the inspection of UV with corona discharge. One of the most important and difficult problems is the basic research of filter design, materials and corona discharge. In this paper, we will report on the UV generation, corona pulse count and the polarity effect of positive and negative DC surface discharge in air. Also, corona discharge characteristics are analyzed using prototype UV camera of Korea. UV generation and corona pulse count due to surface discharge in positive needle is higher than that of negative needle.

An Maximization of Ionic Wind Utilizing a Cylindrical Corona Electrode (관형 코로나 방전전극을 이용한 이온풍속의 최대화)

  • Jung, Jae-Seung;Moon, Jae-Duk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.12
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    • pp.2256-2261
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    • 2010
  • A corona discharge system with needle point or wire type corona electrode has been well used as an ionic wind blower. The corona discharge system with a needle point electrode produces ions at lower applied voltage effectively. However, the corona discharge on the needle point electrode transits to the arc discharge at lower voltage, and it is hard to obtain the elevated electric field in the discharge airgap for enhancing the ion migration velocity due to the weak Coulomb force. A cylindrical corona electrode with sharp round tip is reported as one of effective corona electrode, because of its higher breakdown voltage than that of the needle electrode. A basic study, for the effectiveness of cylindrical electrode shape on the ionic wind generation, has been investigated to obtain an maximum wind velocity, which however is the final goal for the real field application of this kind ionic wind blower. In this paper, a parametric study for maximizing the ionic wind velocity utilizing the cylindrical corona electrode and a maximum ion wind velocity of 4.1 m/s were obtained, which is about 1.8 times higher than that of 2.3m/s obtained with the needle corona electrode from the velocity profile.

The effect of magnet fields on the corona discharge (코로나 방전에 대한 자계의 영향)

  • 박재윤;정장근;김익균
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.3
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    • pp.51-56
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    • 2001
  • In this paper, the effect of magnetic field on corona discharge phenomena was experimentally investigated in the needle-plate electrode geometry. Needle-plate geometry discharge system with magnetic field at a right angle to the electric field was made. The corona discharge characteristics with magnetic field were investigated and compared with the corona characteristics without magnetic field in atmospheric pressure. As a result, in case of positive DC corona discharge with magnetic field, corona discharge zone was significantly wider, corona current was lower, and breakdown voltage was higher than those without magnetic field. However, in case of negative DC corona discharge with magnetic field, corona current was slightly higher and breakdown voltage was lower than those without magnetic field. It is thought that this result is due to cyclotron motion of charged particles such as electron and ion by magnetic field.

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Corona Discharge and Ozone Generation Characteristics of a Wire-to-Wire Gap with a Ferroelectric Pellet Bed (강유전체 충진 선대선 방전갭의 코로나 방전 및 오존 발생특성)

  • Shin, Jung-Min;Bae, Chang-Hwan;Ahn, Chang-Jin;Lee, Jong-Hoon;Moon, Jae-Duk
    • Proceedings of the KIEE Conference
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    • pp.1873-1875
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    • 2003
  • Surface corona discharge characteristics of a ac corona charged ferroelectric pellet barrier have been investigated experimentally. Electric charged stored on the surfaces of the ferroelectric pellets by a at corona discharge provide partial electric fields on the surfaces of the ferroelectric pellets, which could generate surface corona discharges on the ferroelectric pellets. This system utilizes both the surface discharges on the ferroelectric pellet barrier and the corona discharge between wire electrodes. As a result, in the case of the corona discharge with the ferroelectric pellet barrier, the mean corona current and ozone generation increase greatly, and the surface discharges on the ferroelectric pellets can be generated efficiently. It is also found that, the ferroelectric pellet barrier discharge reactor had better discharge characteristics for plasma generation than the wire-to-wire discharge reactor without pellets.

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Surface Discharge Characteristics of a DC Corona Charged Ferroelectric Pellet Barrier (직류 코로나 하전된 강유전체구 층의 연면방전특성)

  • Geum, Sang-Taek;Lee, Geun-Taek;Mun, Jae-Deok
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.5
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    • pp.385-390
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    • 1999
  • Surface corona discharge characteristics of a dc corona charged ferroelectric pellet barrier have been investigated experimentally. Electric charges stored on the surfaces of the ferroelectric pellets by a dc corona discharge provide partial electric fields on the surfaces of the ferroelectric pellets, which could generate surface corona discharges on the ferroelectric pellets. This system utilizes both the surface discharges on the ferroelectric pellet barrier and the corona discharge between corona tip and mesh electrode. Positive and negative dc voltages were applied to the tip to generate partial discharges, and corona currents were estimated to investigate the buildup charge on ferroelectric pellets as a function of the applied time and the charge relaxation time constants of ferroelectric pellets. As a result, in the case of the negative corona discharge with the ferroelectric pellet barrier, the mean corona current and ozone generation increase greatly, and the surface discharges on the ferroelectric pellets can be fenerated efficiently. It is also found that, charge relaxation time, dielectric constants offerroelectric pellets, polarity of applied voltage and applied time affected to the surface discharges among the ferroelectric pellets.

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