• Title/Summary/Keyword: barrier discharge

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Comparative Studies on Soot Oxidation by Nitrogen Dioxide and Ozone

  • Purushothama, C.;Chen, Xin-Hong;Li, Ming-Wei;Chae, Jae-Ou;Sim, Ju-Hyen
    • 한국연소학회:학술대회논문집
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    • 2006.10a
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    • pp.117-121
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    • 2006
  • Non-thermal plasma technology has many applications in various areas. One of the applications is regenerating diesel particulate filter (DPF). DPF is a widely applied device to control the particulate emission of diesel engines. But it needs periodic removal of clogged soot for the smooth running of engine. Conventional high-temperature removal processes easily leads to the breakage of DPF. Herein, low-temperature plasma formed in a dielectric barrier discharge (DBD) reactor was used to form active oxidants such as ozone and nitrogen dioxide. Experimentally, the effects of discharge power and frequency on the performance of DBD reactor were studied. Two oxidants, $O_3$ and $NO_2$, were synthesized and used for incinerating soot in the used DPF. Performances of the two oxidants on the reduction of soot were compared, and it was found that $NO_2$ is more effective than $O_3$ for getting rid of soot

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Performance Enhancement of Gas-Liquid Mixed Plasma Discharge System using High Speed Agitation (고속 교반을 이용한 기-액 혼합 플라즈마방전 시스템의 성능 향상)

  • Park, Young-Seek
    • Journal of Environmental Science International
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    • v.26 no.6
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    • pp.711-717
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    • 2017
  • Dielectric Barrier Discharge (DBD) plasma is a new technique for use in environmental pollutant degradation, which is characterized by the production of hydroxyl radicals as the primary degradation species. Due to the short lifetime of the chemically active species generated during the plasma reaction, the dissolution of the plasma gas has a significant effect on the reaction performance. The plasma reaction performance can be enhanced by combining the basic plasma reactor with a homogenizer system in which the bubbles are destroyed and turned into micro-bubbles. For this purpose, the improvement of the dissolution of plasma gas was evaluated by measuring the RNO (N-dimethyl-4-nitrosoaniline, an indicator of the generation of OH radicals). Experiments were conducted to evaluate the effects of the diameter, rotation speed, and height of the homogenizer, pore size, and number of the diffuser and the applied voltage on the plasma reaction. The results showed that the RNO removal efficiency of the plasma reactor combined with a homogenizer is two times higher than that of the conventional one. The optimum rotor size and rotation speed of the homogenizer were 15.1 mm, and 19,700 rpm, respectively. Except for the lowest pore size distribution of $10-16{\mu}m$, the pore size of the diffuser showed little effect on RNO removal.

Influences of Mesh Shapes and Interspacings on Ozone Generation Characteristics (그물방전극 형상과 방전공격이 오존생에 미치는 영향)

  • Park, Seung-Lok;Lee, Jae-Chan;Moon, Jae-Duk;Jung, Sung-Jin
    • Proceedings of the KIEE Conference
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    • 2000.07e
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    • pp.29-32
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    • 2000
  • Ozone has been widely applied to many industrial fields because of its strong oxidation effects. Therefore, the studies have been progressed for the effective and high concentration of one generation. The silent or surface discharge have been mainly used for high concentration ozone generation until now. But these two types of ozone generators have shortcomings to be improved. In this study, the ozone generator which improved the shortcomings of above two type of ozone generators was proposed and manufactured for high concentration ozone generation. And the proposed ozone generator could generate the surface and barrier discharge simultaneously. For this purpose, a mesh type discharge electrodes were proposed and the experiments were fulfilled as a function of the widths and spacings of mesh electrodes and gap spacings between the dielectric barrier and mesh electrode. When the width of mesh electrode[WM] and spacing of mesh electrode[SM] are 0.3[mm] and 0.8[mm] respectively, the maximum ozone concentration of 2.96[vol%] was obtained at 5.6[kV], 830[mA], gap spacing (S)=0.65[mm].

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Treatment of Ar/O2 Atmospheric Pressure Plasma for Sterilization (아르곤과 산소 대기압 플라즈마 방전 효과를 이용한 살균처리)

  • Son, Hyang Ho;Lee, Won Gyu
    • Applied Chemistry for Engineering
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    • v.22 no.3
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    • pp.261-265
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    • 2011
  • The sterilization effects of atmospheric pressure plasma with the mixture of argon and oxygen were analyzed. The plasma reactor with the shape of dielectric barrier discharge produced the uniform distribution of glow discharge and generated ozone gas effectively according to the various process parameters. The sterilization for E. coli was affected by power, oxygen ratio in the mixture gas, treatment time and distance between reactor and sample. The concentration of ozone was a major source for the sterilization of E. coli, which was enhanced by the increase of power and oxygen ratio. In this study, the effect of atmospheric pressure plasma treatment for the sterilization was confirmed and its result can deliver the atmospheric pressure plasma treatment as the novel sterilization method instead of conventional methods.

Characteristics of Discharges and Plasma Generation in Micro-Air gaps and Micro-Dielectric Barriers (마이크로 유전체장벽 및 마이크로 공격의 방전 및 플라즈마 발생특성)

  • Shon, Si-Ho;Tae, Heung-Sik;Hoon, Jae-Duk
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1835-1837
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    • 1996
  • Characteristics of Discharge and nonthermal plasma generation in a micro-air gap spacing between a micro-dielectric barrier and a electrode have been investigated experimentally to chert the potential to be used as a micro-scale nonthermal plasma generator. It is found that the output ozone concentration, as a nonthermal plasma intensity parameter, of the micro-air gnp nonthermal plasma generator depended greatly upon the air gap spacing and thickness of the dielectric barrier. As a result, there is a optimal air gap sparing in the same micro dielectric barrier to generate ozone effectively. And the higher ozone concentration was generated from the thinner micro-barrier.

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