• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.320-321
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• 2003

대기중에 존재하는 입자상물질은 광범위한 입경역에 걸쳐서 다종다양한 미량화학성분으로 구성되는 분산체이고, 그 성상은 공간적으로도 시간적으로도 크게 변동한다. 입자상 물질의 화학분석법은 발생원 동정을 위한 자료로 적합하며 일반적으로는 습식의 파괴적인 원소분석으로 하는 경우가 많다. 일반적으로 화학적 분석법은 개별입자의 정보가 무시되며 필터에 포집된 bulk 시료에 의한 분석이 진행되므로 장시간 포집에 의한 단시간의 시간변동과 개개의 입자가 가지는 정보가 무시되고 평균화 되어버린다. (중략)

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.10
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• pp.811-819
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• 2009

In the present study, deposition of discrete and small particles on a filter fiber was simulated by stochastic method. Trajectory of each particle was numerically solved by Langevin equation. And Lattice Boltzmann method (LBM) was used to solve flow field around the filter collector for considering complex shape of deposit layer. Interaction between the flow field and the deposit layer was obtained from a converged solution from an inner-loop calculation. Simulation method is properly validated with filtration theory and collection efficiency due to different filtration parameters are examined and discussed. Morphology of deposit layer and its evolution was visualized in terms of the particle size. The particle loaded effect on collection efficiency was also discussed.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.223-226
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• 2002

본 연구에서는 전기집진 기술과 여과집진 기술의 조합에 의한 먼지입자의 포집성능 상승효과를 최대한 높일 수 있는 먼지부하 저감형 하이브리드 집진장치(Hi-Filter)를 개발하기 위해 실험실 규모의 장치를 이용한 실험을 통하여 장치의 최적 형상을 결정하고 그 성능을 검증하였다.(중략)

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.403-408
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• 1996

석탄화력발전소 폐기물인 석탄회와 요오드화 세슘의 반응특성을 DTA(Differential Thermal Analysis), TGA(Thermo-Gravimetric Analysis) 장치를 이용하여 분석하였다. 본연구에 사용된 석탄회는 85%의 실리카와 알루미나를 함유하고 있으며 Si/Al 몰비는 2.1 이었다. DTA와 TGA의 열분석 결과 CsI의 분해, 석탄회와 기체상 세슘의 반응 등으로 이루어져 있다. 석탄회와 CsI의 혼합물은 94$0^{\circ}C$ 이상에서 Pollucite 가 형성되었다. 반응생성물들의 SEM 분석결과 표면이 거칠며 bulky한 crystal 형태로서 구형의 석탄회와는 매우 다른 형상을 보였다. 석탄회는 요오드화세슘의 고정화를 위해서 적합한 알루미노규산염 원료물질들 중의 하나임을 확인하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.6
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• pp.252-257
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• 2016

Dust-collecting behavior of tonpilz transducer was simulated with finite-element-method (FEM) software. In order to optimize the performance of tonpilz transducer, the shape factors including the thickness of head mass, the diameter of tail mass and the depth of bolt were analyzed as variables. As a vibrating energy source, the piezoelectric materials was also tested with PZT-4 and two kinds of piezoelectric single crystals. The output power of the transducer was maximized with the shape factors and then the behavior of the dust-collection was demonstrated with the multi-physics software, COMSOL.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.8
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• pp.619-629
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• 2003

A grease filter is used to remove grease generated from a cooking appliance in a kitchen. Since the inertial impaction is a dominant particle removal mechanism of the grease filter, the performance of the filter is greatly affected by the geometry. This numerical study has been conducted to investigate the effect of geometry on the performance of grease filters for four models having nominal flowrate of 100 m$^3$/h. Four models were designed by changing the shape of impaction surface, the length of eyelid, and the number of eyelids of the grease filter. The flow field and particle trajectories in the grease filter with a flow chamber were simulated using the commercial code of STAR-CD. The difference of air velocity and pressure distributions among four models was discussed in detail. The collection efficiency curves and the pressure drops of four models were also compared. It was found that the grease filter model with flat top surfaces shows highest performance among four models, having high particle collection efficiency and relatively low pressure drop. The cutoff diameter of this model representing 50-% collection efficiency is about 7.1 ${\mu}{\textrm}{m}$ for water droplets at 100 m$^3$/h.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.192-192
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• 2003

오염된 폐수를 처리하는 과정으로 다양한 방법이 사용되고 있으나, 담체를 이용하여 미생물을 배양하고, 미생물에 의해 정수하는 방법이 이용되고 있다. 이를 위해서는 미생물을 배양을 위한 담체의 조건으로 다양한 크기의 연속기공을 갖고, 젖음성과 표면거칠기가 높으며, 이들 중 초기 미생물번식의 조건을 제공하는 기체 포집용 미세기공을 보유하고, 미생물이 성장할 수 있는 수백 $\mu\textrm{m}$까지의 다양한 크기의 연속된 기공을 갖는 미생물 담체용 다공성 세라믹스의 제조를 목적으로 본 연구를 행하였다. 본 연구는 다양한 크기의 기공분포를 형성하기 위하여 첨가물로 activated carbon과 무기염, 고분자 binder를 활성알루미나 기지재료에 사용하여 수열반응에 의해 각각의 물질이 형성할 수 있는 기공의 크기를 확인하고, 수 nm에서 수백 $\mu\textrm{m}$까지의 연속된 기공이 존재하는 담체를 제조하였다. 수열조건과 첨가물의 양에 따라 수은침투가압을 이용하여 기공의 크기와 분포를 측정하고 평균기공률을 얻을 수 있었고, 압축강도를 측정하고, 기공의 형상을 주사전자현미경을 통해 확인하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1519-1526
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• 2013

This study reviewed the capturing performance of a canopy hood used in some melting processes of a casting manufacturing factory through a site survey. In addition, this study compared and evaluated the flow field and pressure field for the plans to enhance the hazardous air pollutants collection capacity by using CFD model. The case-2(flange attached + double hood) can be improved in terms of collection performance, but is expected to increase in hood static pressure by about 70% more than the existing structure, so it was shown that its site applicability is not good. It is judged that the shape of case-3(flange attached + double cone attached) is most suitable to improve the suction efficiency. This is because a double cone is installed at the center of the opening to concentrate the flow rate on the edge of the hood and control the hume rising to the center of the hood without a static pressure rise via the slope of the cone.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.6-13
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• 2017

This study examines the effect of the type and number of orifices in an in-line mixer to improve the mixing performance and pressure loss. Recently, in-line non-power-consuming mixers have been increasingly used to complement mechanical mixers, which have a long dwell time, noise, excessive energy consumption, and high maintenance costs. An in-line mixer with an orifice for efficient mixing in water treatment was examined by numerical analysis using the commercial code FLUENT. The flow characteristics of pressure loss and velocity distribution within the mixer and the mixing efficiency were compared with and without the orifices. The CFD results show that the mixing efficiency was improved, but the pressure loss was increased by the in-line mixer with an orifice. A sensitivity study was also done on the principal parameters.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.3
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• pp.117-126
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• 1987

The author has analysed profile of flow in rear of motion with single ball with low Reynolds number performed interface layers. For each system whose viscosity of the lower phase is as large as or large that of the upper phase, the profile has based on the thickness of the ball in the lower phase is nearly independent of both the ball single and the physical properties of the upper phase of the solution. The examine of the characteristics between Darwin's total displacement of the fluid and data obtained in this study, the averaged volume of each cases was corrected by the viscosity in the lower phase. When the viscosity in the lower phase is less than that of the upper phase, the volume based on the displacement of the fluid in rear region of ball are influenced by both ball size and the viscosity ratio of the upper phase to the lower phase. In the range of the Reynolds number less than a constant values, the volume ratio is influenced by both Reynolds number and Moltion number but mainly Reynolds. In range of Reynolds number over than the value, the volume ratio is independent of Reynolds number, but influenced by Moltion number.