• Title/Summary/Keyword: Corona Discharge

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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.

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.

Effect of Long-term Corona-discharge on RTV Silicone Rubber (장기 코로나 처리에 따른 RTV 실리콘 절연재료의 특성변화)

  • 연복희;안종식;허창수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.266-269
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    • 2001
  • This paper investigated the aging characteristic under long-term corona discharge on loon temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge, the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains (CH$_3$) and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

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Effect of Long-term Corona-discharge on RTV Silicone Rubber (장기 코로나 처리에 따른 RTV 실리콘 절연재료의 특성변화)

  • Youn, Bok-Hee;Ahn, Jong-Sik;Huh, Chang-Su
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.266-269
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    • 2001
  • This paper investigated the aging characteristic under long-term corona discharge on roan temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge. the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains $(CH_3)$ and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

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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.

Multiple-Wire Corona Discharge TEA-$CO_2$ Laser의 설계 및 제작

  • 김기호;오차환;이상수
    • Proceedings of the Optical Society of Korea Conference
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    • 1988.06a
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    • pp.41-46
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    • 1988
  • 본 논문에서는 wire discharge 방법의 응용인 Multiple-wire corona discharge (NW CD)의 preionization field를 계산하였고, 동일한 조건하에서 Surface corona discharge (SCD) 와 Wide discharge(WD) 의 preionization filed와 비교하여보았다. 그에 따른 결과로써 NWCD가 고출력 TEA-CO2 레이저에 가장 좋은 선전리 방법임을 알 수 있었다.

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Corona discharge characteristics of ceramic discharge plate (세라믹 방전판의 코로나 방전 특성)

  • 최규남
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.36T no.3
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    • pp.72-78
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    • 1999
  • The frequency characteristics of surface corona discharge from the electrodes on the ceramic substrate ozonator were investigated. The frequency characteristics of dark current were compared with that of corona discharge. Switching frequency which was the fraction of resonant frequency was found to be effective for corona discharge. This is regarded to distort the electric field distribution on the discharge plate which is essential for corona discharge. The measurement showed the efficiency of 28mg/W ozone generation when the switching frequency was 1/5 of the resonant frequency.

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A Study on Ageing Characteristics of RTV Silicone Coating Materials by Corona Discharge (RTV 실리콘 코팅재의 코로나 방전 열화 특성)

  • 한세원;한동희;조한구
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.8
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    • pp.359-364
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    • 2003
  • Ageing characteristics of RTV coating materials by corona discharge have been studied. The hydrophobicity recovery of RTV coating materials with 300${\mu}{\textrm}{m}$ thickness was identical with a bulk silicone materials. The RTV coating materials hydrophobicity has been almost lost when its were discharged during 40 seconds by corona discharge of 10㎸, and recovered after about 45 hours. The resistivity of RTV coating materials has not been recovered after 45 hours, though after 80 hours the initiation resistivity value has been recovered up to 95%. There was no critical change of compounds(such as Si and Al) on RTV surfaces by the corona discharge treatment until 100 seconds. In the test of arc erosion, it was seen that the coating sample with silicone rubber as a base material have more longer burn-out time than other samples with FRP or glass base.

Development of a High Energy Ignition System Using Corona Discharge (코로나 방전을 이용한 고에너지 점화 시스템 개발)

  • Park, Kyongseok;Choi, Duwon;Kang, Hyehyun;Lee, Jonghwa;Park, Jinil
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.6
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    • pp.650-655
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    • 2015
  • A high energy ignition system is essential for lean burn or high EGR gasoline engine, which is getting more and more interest to improve fuel economy. The high energy ignition systems comprise plasma jet, laser beam, corona discharge and so on. In this study, a high energy ignition system using corona discharge is developed and tested in a constant volume combustion chamber. The developed system shows extension of lean limit of propane-air mixture and enhencement of combustion speed. Various shape of corona discharge plugs are also tested and compared in this study.

Spectroscopic Identification of Isomeric 2,3- and 2,6-Dimethylbenzyl Radicals in Corona Discharge

  • Yoon, Young Wook;Lee, Sang Kuk
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.763-767
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    • 2013
  • We resolved the controversial assignments of the visible vibronic bands observed from corona discharge of 1,2,3-trimethylbenzene. The vibronic bands belonging to the jet-cooled 2,6-dimethylbenzyl radical were clearly identified from the spectrum observed from corona discharge of 2,6-dimethylbenzyl chloride. After subtracting the bands of the 2,6-isomer from the spectrum observed from corona discharge of 1,2,3-trimethylbenzene, the vibronic bands of the 2,3-isomer were also identified. By comparing data with the known vibrational data of 1,2,3-trimethylbenzene and the results of ab initio calculations, we determined the electronic energies of the $D_1{\rightarrow}D_0$ transitions and vibrational mode frequencies in the ground electronic states of the 2,3-and 2,6-dimethylbenzyl radicals.