• 한국기계가공학회지
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• 제21권5호
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• pp.40-45
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• 2022

In recent years, indoor air pollution has become a crucial environmental problem. Hence, the purification of indoor air is an important issue. Typical physical filters show relatively high dust collection efficiency at a dust particle size of more than 5.0 ㎛ but extremely low efficiency at an ultrafine size of less than 2.5 ㎛. In this study, an electric field filter was proposed to capture ultrafine dust with a size of less than 5.0 ㎛. Simulation results showed that the electric field filter effectively removed ultrafine dust. In addition, sufficient dust collection efficiency was obtained even with a simple plate-shaped filter without bending the Chevron filter.

• 한국대기환경학회지
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• 제28권6호
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• pp.675-687
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• 2012

Applying an external electric field across air filter media is one of methods to improve the filtration performance. Metal wire meshes have been commonly used as electrodes situated on both sides of a thick filter pad. For a thin filter medium a short circuit, known as the biggest drawback for applying an external electric field to air filter, can occur at the closest point between electrodes. In this study several types of insulated meshes were prepared by coating #50 meshes with a dielectric material, Nylon 66, and the filtration property of air filter was evaluated at the presence of external electric field using those insulated meshes as electrodes and compared with that of filters using bared meshes. The collection efficiency of tested filter was increased from 78% to 95% for singly charged 100 nm particles by application of external electric field. As a result, there was no significant difference in collection efficiency between filters with insulated and bared electrodes. Similar results could be also seen from the tests using polydisperse particles. Finally, through this study, we found that the insulation of mesh electrodes doesn't affect the filtration performance of fibrous air filter under external electric field.

• 에너지공학
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• 제5권2호
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• pp.138-145
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• 1996

The particulate collection at high temperature and high pressure (HTHP) is important on the advanced coal power generation system not only to improve the thermal efficiency of the system, but also to prevent the gas turbine from erosion and to meet the emission limits of the effluent gas. The specifications for particulate collection in those systems such as Integrated Coal Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) require the absolutely high collection efficiency and reliability. Advanced cyclone, granular bed filter, electrostatic precipitator, and ceramic filter have been developed for particulate collection on the advanced coal power generation system. However, rigid ceramic filters and granular bed filter among them show the best potential. The current technology of these collectors was evaluated in this paper. The experienced problems of these systems on performance, materials, and mechanical design were investigated. Ceramic candle filters has the best potential for IGCC at this moment because it has nearly the highest efficiency comparing with other filtering systems and has accumulated many reliable design data resulted from many field experiences.

• 한국대기환경학회지
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• 제31권2호
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• pp.118-130
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• 2015

Fine dust containing iron compounds is of current interests in metro subway as well as large scale industries including iron manufacturing and smelting works. This work attempts to find a new design of magnetic filter module for iron dust capture. It simulated the vertical rectangular duct with metal mesh which might promote electric fields in the duct space. A lab test using coal fly ash composed of 8.66% Fe with the most form of $Fe_3O_4$ and $Fe_2O_3$ showed capability of magnetic collection. It showed the capture efficiency with 80~93% for $PM_{2.5}$ depending on magnetic intensity. Ferromagnetic wire mesh contributed up to 50% of collection increment.

• 디지털융복합연구
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• 제20권2호
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• pp.339-344
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• 2022

본 연구에서는 공장 및 대형 시설에서 사용되고 있는 전기집진장치에 대하여 미세분진이 효율적으로 얼마나 제거 될 수 있는지에 대한 내용이다. 미세분진 제거 효율을 평가한 결과는 다음과 같다. 10,000 V 에서는 Efficiency method I은 68.1 % 를 보였고, Efficiency method I는 58.6 %로 Efficiency method I의 효율 보다 낮은 효율을 보였다. 5,000 V 에서는 Efficiency method I은 57.6 %를 보였고, Efficiency method II는 51.6 %로 Efficiency method I보다 낮은 효율을 보였다. 2,500 V 에서는 Efficiency method I은 50.3 %를 보였고, Efficiency method II는 24.4 %로 Efficiency method I보다 낮은 효율을 보였다. Efficiency method I의 경우 전 분진농도와 필터 통과 후 분진농도을 활용하여 계산한 효율이다. Efficiency method II는 필터 후의 공기와 오염된 공기가 혼합되는 환경에서 조금 더 정확한 효율을 측정하기 위해 Efficiency method II를 계산하였다. Efficiency method II는 Efficiency method I보다 낮은 효율을 나타내었다. 전기집진장치 실험 결과 10,000 V에서 집진 성능이 가장 높게 나타났으며, 그 다음 5,000 V, 2,500 V의 순을 보였다.

• Journal of Radiation Protection and Research
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• 제22권4호
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• pp.309-317
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• 1997

비파괴적인 방법으로 방사성폐기물드럼에 대한 핵종분석을 수행할 때 드럼내 매질에 의한 방사선의 감쇠에 의해 핵종분석장치로 측정한 계수값은 실제 드럼내 방사능에 의한 계수값보다 작게 나타나 결과적으로 방사능의 측정결과가 과소평가된다. 그러므로 드럼내 매질에 의한 감쇠를 보정해 주어야 하는데 감쇠 보정방법은 드럼내 매질의 분포나 매질의 밀도에 따라 달리 적용해야 한다. 본 연구에서는 원자력발전소에서 발생하는 드럼 종류별로 모델드럼을 제작한 후 모델드럼에 표준감마선원을 넣고 핵종분석장치를 이용해 측정을 하여 드럼내 매질의 밀도를 구하였고, 이 값을 실제 매질의 밀도와 비교해 드럼종류에 따라 매질에 의한 최적의 감쇠 보정방법을 결정하였다. 그 결과 잡고체드럼의 경우에는 전송선원 보정방법과 평균밀도 보정방법, 차폐잡고체드럼의 경우 전송선원 보정방법과 두 감마선피크비교 보정방법이 최적의 감쇠 보정방법임을 알 수 있었고, 고밀도드럼인 폐수지, 농축폐액 및 폐필터드럼의 경우에는 평균밀도 보정방법과 두 감마선피크비교 보정방법을 사용해 드럼내 매질의 감쇠를 보정할 수 있다.