• 청정기술
• /
• 제15권1호
• /
• pp.54-59
• /
• 2009

비튜멘으로부터 효과적으로 물을 제거하기 위하여 화학적 항유화제에 의한 물/비튜멘 에멀젼의 분리를 연구하였다. 비튜멘 에멀젼을 모사하기 위해 모사물질로 엔진오일(GS Caltex Deluxe Gold V 7.5W/30, Hyundai gear oil 85W/140)과 아스팔트(AP-5, KS M 2201, (주)동남유화)를 사용하여 예비실험을 수행하였다. 그리고 오일센드로부터 추출한 비튜멘을 이용하여 실험하였다. 예비실험으로 수행된 물/오일 에멀젼의 분리실험에서 함유화제를 첨가하지 경우 에멀젼이 분리되지 않았으며, 항유화제의 농도가 낮을 때 Hyundai 엔진오일은 GS Caltex 엔진오일보다 분리효율이 높았다. 그러나 GS Caltex 엔진오일에 비해서 분리효율의 증가율은 낮았다. Hyundai 엔진오일은 GS Caltex 엔진오일보다 점도가 높아서 물의 분산이 잘 이루어지지 않았기 때문으로 판단된다. 그리고 HLB (hydrophilic-lipophilic balance) 값이 높을수록 분리효율이 높았으며, 사용된 항유화제 중 TWEEN 20 (polyoxyethylene sorbitan monolaurate solution)이 가장 좋은 분리효율을 나타내었다.

• International Journal of Fluid Machinery and Systems
• /
• 제3권3호
• /
• pp.260-270
• /
• 2010

Reducing the losses of the tip clearance flow is one of the keys in an unshrouded centrifugal compressor design and development because tip clearances are large in relation to the span of the blades and also centrifugal compressors produce a sufficiently large pressure rise in single stage. This problem is more acute for a low flow high-pressure ratio impeller design. The large tip clearance would cause flow separations, and as a result it would drop both the efficiency and surge margin. Thus a design of a high efficiency and wide operation range low flow coefficient centrifugal compressor is a great challenge. This paper describes a recent development of high efficiency and wide surge margin low flow coefficient centrifugal compressor. A viscous turbomachinery optimal design method developed by the authors for axial flow machine was further extended and used in the centrifugal compressor design. The compressor has three main parts: impeller, a low solidity diffuser and volute. The tip clearance is under a special consideration in this design to allow impeller insensitiveness to the clearance. A patented three-dimensional low solidity diffuser design method is used and applied to this design. The compressor test results demonstrated to be successful to extend the low solidity diffusers to high-pressure ratio compressor. The compressor stage performance showed the total to static efficiency of the compressor being about 85% and stability range over 35%. The test results are in good agreement with the design.

• Journal of Magnetics
• /
• 제22권2호
• /
• pp.214-219
• /
• 2017

Magnetic separators that clean the fluid stream from impurities, protect the installations in numerous industries. This paper introduces a graphical user interface (GUI) which proposes an optimized coil separating magnetic particles with a radius from 1 up to 500 µm. High gradient magnetic fields are employed in an arbitrary user defined fluidic channel which is made of a nonmetallic material. The effects of coil parameters are studied and adjusted to design an optimum coil with a minimum Ohmic loss. In addition, to design the coil scheme based on the particle movements, a mathematical particle-tracing model within the fluid channels has been utilized. In comparison to conventional magnetic separators, this model is reconfigurable by the user, produces a weaker magnetic field, allows for continuous purifying and is easy to install, with high separation efficiency. The presented GUI is simple to use, where the coil's manufacturing limitations can be specified.

• 한국초전도ㆍ저온공학회논문지
• /
• 제23권3호
• /
• pp.14-19
• /
• 2021

The reduction of carbon dioxide emissions becomes a global issue, the main source of carbon dioxide emissions in the Asian region is the energy conversion sector, especially coal-fired power plants. We are working to develop technologies that will at least limit the increase in carbon dioxide emissions from the thermal power plants as one way to reduce carbon dioxide emissions. Our research aims to reduce carbon dioxide emissions by removing iron oxide scale from the feedwater system of thermal power plants using a superconducting high-gradient magnetic separation (HGMS) system, thereby reducing the loss of power generation efficiency. In this paper, the background of thermal power plants in Asia is outlined, followed by a case study of the introduction of a chemical cleaning line at an actual thermal power plant in Japan, and the possibility of introducing it into the thermal power plants in China based on the results.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
• /
• pp.338-341
• /
• 2002

This work is the basis research to apply Hydrocyclone for the separation and the thickening to the reservoir sediment. Chemical analysis result showed that organic contaminants were abundantly found in smaller sediment particles. As a result of the experiment device that higher reduced efficiency was obtained under the high velocity and low concentration with the small cyclones.

• Journal of Electrochemical Science and Technology
• /
• 제8권3호
• /
• pp.250-256
• /
• 2017

A graphene electrode with a novel in-plane structure is proposed and successfully adopted for use in supercapacitor applications. The in-plane structure allows electrolyte ions to interact with all the graphene layers in the electrode, thereby maximizing the utilization of the electrochemical surface area. This novel structure contrasts with the conventional out-of-plane stacked structure of such supercapacitors. We herein compare the volumetric capacitances of in-plane- and out-of-plane-structured devices with reduced multi-layer graphene oxide films as electrodes. The in-plane-structured device exhibits a capacitance 2.5 times higher (i.e., $327F\;cm^{-3}$) than that of the out-of-plane-structured device, in addition to an energy density of $11.4mWh\;cm^{-3}$, which is higher than that of lithium-ion thin-film batteries and is the highest among in-plane-structured ultra-small graphene-based supercapacitors reported to date. Therefore, this study demonstrates the potential of in-plane-structured supercapacitors with high volumetric performances as ultra-small energy storage devices.

• 한국세라믹학회지
• /
• 제45권10호
• /
• pp.605-609
• /
• 2008

This work describes the preparation of functionalized magnetic nanoparticles(MNPs) and their bioapplication to human DNA separation. Silica coated MNPs were prepared by changing the volume ratio of tetraethyl orthosilicate(TEOS) for controlled coating thickness on the original nanoparticle of MNPs. The sol-gel process in silica coating on MNPs surface was adapted for relatively mild reaction condition, low-cost, and surfactant-free. And then amino functionalized magnetic nanoparticles were synthesized using amine groups as surface modifiers. The result of adsorption efficiency for human DNA with amino-functionalized silica coated MNPs was calculated as a function of the number of amine groups.

• 약학회지
• /
• 제41권5호
• /
• pp.539-546
• /
• 1997

Capillary electrophoresis (CE) is perceived as an attractive tool for the analysis of pharmaceuticals and biological materials because of their high separation efficiency, easy separation and low running cost. New concept of micellar electrokinetic capillary chromatography (MECC) expanded the application of CE to the separation of neutral molecules. Validation of CE as an analytical technique for quality control of pharmaceuticals should be confirmed by quantitative analysis and the peak confirmation. In this study, the quantitative analyses of various types of neutral, acidic and basic components (acetaminophen, caffeine, ascorbic acid, riboflavin, thiamine, chlorpheniramine, phenylpropanolamine, dl-methylephedrine and dextromethorphan) in complex cold medicines have been accomplished using CE. Combined methods of MECC using SDS and capillary zone electrophoresis lowering the pH of running buffer were adopted to determine the ingredients in capsule type or liquid formula complex medicines without particular sample pretreatment. The results indicate that CE is a promising technique for quality control analysis of pharmaceuticals as a validation method.

• 자원리싸이클링
• /
• 제16권5호
• /
• pp.71-76
• /
• 2007

가정에서 분리 배출된 폐플라스틱은 일반적으로 수선별 등 분리선별 공정을 거친 후 종말품으로 회수되어, 현재 대부분이 매립이나 소각되고 있다. 혼합폐플라스틱 종말품의 경우 2006년 약 175만톤 발생된 것으로 예측되고 있으나, EPR실시 이후로 발생량은 2000년에 비해 2배 이상 크게 증가한 실정이다. 특히, 혼합폐플라스틱 종말품의 경우 PVC 함량(4 wt.% 이하)이 매우 높아 이들의 재활용에 커다란 제약이 되고 있다. 본 연구에서는 혼합폐플라스틱 종말품으로부터 풍력 및 습식 비중선별장치를 이용하여 폴리올리핀계 (PE, PP, PS) 플라스틱을 경량물로 회수하는 선별시스템을 개발하였다. 본 선별시스템은 풍력선별, 자력선별, 1단계 파쇄, 정량공급 및 습식 비중선별 공정으로 구성되어 있으며, 습식 비중선별 공정은 원심분리를 기본으로 혼합-세척-선별 및 탈수가 단일장치내에 집약된 특징이 있다. 또한, 본 연구에서는 연질 플라스틱의 분쇄 효율을 크게 개선한 파쇄기를 개발하였다. 개발된 습식 비중선별장치의 용량은 시간당 0.5 톤으로, 이를 이용하여 회수된 경량물의 PVC 함량은 0.3wt.% 이하이며, 경량 및 중량 회수물의 수분 함량도 각각 10% 이하를 달성하였다.

• 멤브레인
• /
• 제26권1호
• /
• pp.14-25
• /
• 2016

분리막 시스템은 기존의 분리공정과 비교하여 우수한 효율과 낮은 가격으로 인하여 빠르게 성장하고 있다. 분리막 공정은 분리막, 모듈, 그리고 기계적 요소로 구성되어 있으며 향상된 효율을 얻기 위하여 분리막 공정에 사용되는 소재의 요구사항 또한 증가가 되고 있다. 분리막 모듈은 분리막 시스템의 핵심 요소 중 하나로써 최근 들어 복합 소재들이 스테인레스강 모듈과 비교하여 우수한 물성과 낮은 가격으로 인해 분리막 하우징에 적용되어 왔다. 본 리뷰에서는 다양한 종류의 유리섬유와 이를 이용한 복합소재들에 대하여 정리하였으며 분리막 시스템에 적용을 위한 잠재성에 대하여 논의하였다.