• Title/Summary/Keyword: Electrolytic-reduction

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The Study of Ripple Reduction of the PFC CCM Flyback Converter without Electrolytic Capacitor for LED Lightings using LC Resonant Filter (LC 공진 필터를 이용한 전해 커패시터 없는 LED 구동용 PFC CCM 플라이백 컨버터의 출력 전류 리플 저감에 관한 연구)

  • KIm, Choon-Tack;Kim, Young-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.4
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    • pp.601-610
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    • 2016
  • The light-emitting diode (LED) has been used in a variety of industrial fields and for general 0lighting purposes on account of its high efficiency, low power consumption and long lifespan. The LED is driven by direct current; therefore, an AC/DC converter is typically required for its use. An electrolytic capacitor is generally used for stabilizing DC voltage during use of the AC/DC converter. However, this capacitor has a short lifespan, which makes it a limiting factor in LED lighting. Furthermore, LED lighting requires a dimmable control to enable energy savings and fulfil a growing consumer demand. In this paper, the dimmable single-stage power factor correction (PFC) continuous conduction mode (CCM) flyback converter that employs no electrolytic capacitor is presented. The LC resonant filter is alternatively applied to reduce the 120[Hz] ripple on the output. And the optimum value of the LC resonant filter parameters considering both efficient and performance is analysed. Simulation and experimental results verify the satisfactory operation of the converter.

Separation Performance and Application of Sericin Protein in Silk Degumming Solution(1) (실크 정련 세리신 단백질의 분리특성과 응용(1))

  • Cha, Chin-U;Bae, Kie-Seo;Park, In-Woo;Kim, Yong-Duck;Hong, Young-Ki
    • Textile Coloration and Finishing
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    • v.21 no.6
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    • pp.56-63
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    • 2009
  • In this study we have evaluated the separation characteristics and concentration of sericin using tubular type ultrafiltration membrane in silk degumming solution that extracted from electrolytic reduction water process. Ultrafiltration membranes have used in sericin separation performance and the separation characteristics of membrane satisfied typical Hagen-Poiseuille equation. It had the increase of flux according to the increase of feed pressure and temperature in occasion of pure water flux. And also the flux and solute rejection had about $25{\sim}60{\ell}/m^2{\cdot}h$ and more than 95% in sericin feed solution with concentration 1.00~1.89% at feed pressure force of $3{\sim}8kgf/cm^2$ respectively. In addition, the separation performance of tubular type ultrafiltration membrane for silk degumming solution was very steady-state with long experiment time.

HOT CELL RENOVATION IN THE SPENT FUEL CONDITIONING PROCESS FACILITY AT THE KOREA ATOMIC ENERGY RESEARCH INSTITUTE

  • YU, SEUNG NAM;LEE, JONG KWANG;PARK, BYUNG SUK;CHO, ILJE;KIM, KIHO
    • Nuclear Engineering and Technology
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    • v.47 no.6
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    • pp.776-790
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    • 2015
  • Background: The advanced spent fuel conditioning process facility (ACPF) of the irradiated materials examination facility (IMEF) at the Korea Atomic Energy Research Institute (KAERI) has been renovated to implement a lab scale electrolytic reduction process for pyroprocessing. The interior and exterior structures of the ACPF hot cell have been modified under the current renovation project for the experimentation of the electrolytic reduction process using spent nuclear fuel. The most important aspect of this renovation was the installation of the argon compartment within the hot cell. Method: For the design and system implementation of the argon compartment system, a full-scale mock-up test and a three-dimensional (3D) simulation test were conducted in advance. The remodeling and repairing of the process cell (M8a), the maintenance cell (M8b), the isolation room, and their utilities were also planned through this simulation to accommodate the designed argon compartment system. Results and conclusion: Based on the considered refurbishment workflow, previous equipment in the M8 cell, including vessels and pipes, were removed and disposed of successfully after a zoning smear survey and decontamination, and new equipment with advanced functions and specifications were installed in the hot cell. Finally, the operating area and isolation room were also refurbished to meet the requirements of the improved hot cell facility.

Removal of Cu impurities in LiBr solution using cyclone electrowinning method (싸이클론 전해환원방법을 이용한 LiBr 용액내의 Cu 불순물 제거에 관한 연구)

  • Da Jung Park;Kyu Hwan Lee
    • Journal of the Korean institute of surface engineering
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    • v.57 no.2
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    • pp.92-97
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    • 2024
  • The LiBr aqueous solution, which is the absorption liquid of absorption refrigerator, must be replaced periodically because the concentration of impurities such as Cu2+, Fe2+, Ca2+, etc., increases due to corrosion of the tubes as the period of use increases, and the refrigeration efficiency decreases significantly. In order to reuse the waste absorption liquid, flocculation-precipitation method is mainly applied to precipitate the impurities, which requires hundreds of times the concentration of impurities and generates additional waste. In this study, a process for removing Cu ion impurities from cyclone electrolyzer by electrolytic reduction is presented in a small-scale facility without additional waste. It was confirmed that Cu ion impurities can be removed down to 1 ppm by electrolytic reduction process, and to further improve the removal rate, the mass transfer rate was increased by using a cyclone electrolyzer. The removal rate of Cu ions increased with the increase of flow rate and current density, and it was confirmed that Cu was removed at a rate of 1.48 ppm/h under the condition of 330 mL/sec and 2.5 mA/cm2.

Recovery of Tin with High Purity for Dental Materials from Waste Tin oxide by Reduction and Electro Refining (폐주석산화물로부터 환원공정 및 전해정련을 통한 치과용 고순도 주석 회수)

  • Jung, Hyun-Chol;Kim, Sang-Yeol;Lee, Min-Ho
    • Resources Recycling
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    • v.27 no.6
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    • pp.38-43
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    • 2018
  • In this study, using electro-refining process and methane gas reduction, we performed studying the recovery of tin with high purity from waste tin oxide had used as a electrode rod of ceramic furnace which occurred during glass production process. We recovered the crude tin of 99% purity from a methane gas reduction process and controlled a little amount of impurities. When the electrolytic refining condition was a current density of $60A/dm^2$ and the sulfuric acid concentration of 0.75 mol, 96.8% of recovered tin (99.979% of purity) were recovered during the electrolytic refining. We confirmed that toxic impurities such as Pb, Sb included in electrode rod. could be controlled.

Studies of the Passivation Film as a Function of the Concentration of Electrolyte in Lithium-ion Battery

  • Jeong, Gwang Il;Jeong, Myeong U;Kim, U Seong;Kim, Sin Guk;Seong, Yong Eun;Choe, Yong Guk
    • Bulletin of the Korean Chemical Society
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    • v.22 no.2
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    • pp.189-193
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    • 2001
  • The irreversible capacities caused by the reduction of solvent on the surface of a negative electrode (KMFC:Kawasaki Mesophase Fine Carbon) were examined during the initial cycle in ethylene carbonate (EC)-diethyl carbonate (DEC) electrolyte solut ions at various concentrations of LiPF6. Chronopotentiograms, linear sweep voltammograms, and impedance spectra clearly showed differences in irreversible capacity and that those differences are related to the concentration of electrolyte during the initial charge. These differences were caused by the amount of solvent decomposition as a function of the concentration of LiPF6 electrolytic salt. The data are discussed with reference to the concentration of electrolytic salt and the properties of passivation film formed by solvent decomposition.

Residual Liquid Behavior Calculation for Vacuum Distillation of Multi-component Chloride System (다성분 염화물계 진공 증류의 잔류 액체 거동 계산)

  • Park, Byung Heung
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.3
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    • pp.179-189
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    • 2014
  • Pyroprocessing has been developed for the purpose of resolving the current spent nuclear fuel management issue and enhancing the recycle of valuable resources. An electrolytic reduction of the pyroprocessing is a process to reduce oxides into metals using LiCl as an electrolyte and requires a post-treatment process due to the inclusion of residual salt in porous metal products. A vacuum distillation has been adopted for various molten salt systems and could be applied to the post-treatment process of the electrolytic reduction. The residual salt in the metal products includes LiCl, alkali chlorides, and alkaline earth chlorides. In this paper, vapor pressures of chlorides have been estimated and the composition changes on the residual liquid during the vacuum distillation process have been calculated. A model combining a material balance and vapor-liquid equilibrium relations has been proposed under a constant vapor discharging flow rate and liquid composition changes have been calculated using the vapor pressures with respect to a dimensionless time. The behaviors have been compared with temperature and molten salt composition changes to simulate the process condition variation. The distillation of the residual salt has been dominated by LiCl which is the main component of the salt and CsCl of which vapor pressure is higher than that of LiCl would be readily removed. RbCl exhibits similar vapor pressure with LiCl and maintains its composition. However, $SrCl_2$ and $BaCl_2$ of which vapor pressures are much lower than that of LiCl are concentrated with time and expected to be possibly precipitated during the distillation when the initial compositions are increased.