• 산업기술연구
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• 제18권
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• pp.249-258
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• 1998

In this paper, we investigated the post-combustion removal of nitrogen oxide($NO_x$) and sulfur oxide($SO_x$) which is based on the gas to particle conversion process by the pulsed corona discharge. Under normal pressure, the pulsed corona discharge produces the energetic free electrons which dissociate gas molecules to form the active radicals. These radicals cause the chemical reactions that convert $SO_x$ and $NO_x$ into acid mists and these mists react with $NH_3$ to form solid particles. Those particles can be removed from the gas stream by conventional devices such as electrostatic precipitator or bag filter. The reactor geometry was coaxial with an inner wire discharge electrode and an outer ground electrode wrapped on a glass tube. The simulated flue gas with $SO_x$ and $NO_x$ was used in the experiment. The corona discharge reactor was more efficient in removing $SO_x$ and $NO_x$ by adding $NH_3$ and $H_2O$ in the gas stream. We also measured the removal efficiency of $SO_x$ and $NO_x$ in a cylinder type corona discharge reactor and obtained more than 90 % of removal efficiency in these experimental conditions. The effects of process variables such as the inlet concentrations of $SO_x$, $NH_3$ and $H_2O$, residence time, pulse frequencies and applied voltages were investigated.

• Journal of Advanced Marine Engineering and Technology
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• 제38권7호
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• pp.834-843
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• 2014

본 연구에서는 마이크로 탄소 브러쉬 하전부와 평판형 금속 집진부로 구성된 저전력 소비형 2단형 전기집진기를 개발하였고, 특히 인체 위해성이 높은 $0.3{\mu}m$급의 미세한 오일 미스트에 대한 인가전압 및 소비전력별 집진효율 특성을 실험연구를 통해 고찰하였다. 하전부의 인가전압에 따른 단위 입자당 하전율과 입경별 집진효율을 측정함과 동시에 이론에 근거한 계산값과 비교해 보았으며, 9 주 동안의 장시간 운전을 통해 지속적으로 포집된 오일 미스트에 의한 전기집진기의 성능을 열유체역학적인 관점에서 변화를 조사하였다.

• 생태와환경
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• 제45권1호
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• pp.102-109
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• 2012

본 연구는 자연수와 인공조류 배양수(BG-11 medium) 등 두 가지 부영양 실험수를 이용하여 네 가지의 여재(스펀지, 화산석, 활성탄, 수산화마그네슘)의 단독 및 혼합여재 적용에 따른 조류 및 인 제거효과를 조사하였다. 혼합여재는 컬럼 여과장치에 각각의 여재를 충진후, 스펀지, 화산석, 활성탄, 수산화마그네슘의 순서로 연결하여 단독으로 여과할 때와 서로 비교하였다. 또한 여재로 사용한 수산화마그네슘의 첨가량 및 입자크기를 조절하여 인 제거효과를 비교하였다. 수산화마그네슘은 두 가지 입경(2 mm 이상 및 이하) 모두에서 높은 인 제거효과를 보였으며, 반응시간 및 첨가량 증가에 따라 인 제거효과가 증가하였다. 단독여재의 적용 결과, 4가지 여재 중 활성탄은 조류 및 인 제거에 매우 효과적인 것으로 나타났다. 또한 활성탄을 이용한 단독여재와 비교하여 혼합여재를 통해 가장 높은 인 제거효율을 확인하였다. 이러한 결과를 토대로 혼합여재의 경우에는 제거효율이 높았던 활성탄과 수산화마그네슘 등의 조합 적용이 상승작용을 나타낸 것으로 사료된다.

• 대한기계학회논문집B
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• 제34권1호
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• pp.27-34
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• 2010

본 연구에서는 순환방식의 1000 CMH급 전기집진장치 성능평가 시스템 구축하여, 대용량 순산소 연소 장치 없이 순산소 연소가스 모사 조건(고농도 $CO_2$ 조건)에서 엣지-평판형 전기집진장치를 방전극 형상, 집진판 간격, 유입속도, 가스조성 및 분진 입경에 따라 성능을 평가하였다. $CO_2$ 70% 조건에서 3 종 방전극에 대해 성능 비교를 한 결과, 방전극 편 면적이 넓은 방전극이 상대적으로 높은 포집효율을 나타내었다. 또한 유입속도가 감소할수록, 분진 입경이 증가할수록, 집진판 간격이 좁을수록 분진 집진 효율이 증가하였으나, $CO_2$ 농도가 증가할수록 효율이 감소하였다. 그러므로 $CO_2$ 농도가 높을 것으로 예상되는 순산소 연소 등 배기가스 조건에 적용되는 전기집진장치를 설계할 경우, 기존과 동일한 단위 가스 체적 당 코로나 전력 조건에서 집진장치 내부 유속을 줄이거나 집진판 간격을 좁히는 설계변화가 요구되며, 방전극의 경우 방전편 면적이 넓으면서 코로나 전류가 높은 방전극이 적용되야 할 것으로 판단된다.

• 대한환경공학회지
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• 제31권4호
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• pp.256-262
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• 2009

도시지역 비점오염부하를 저감하는 장치 중에서 수리동력학적 분리장치(HDS)는 가장 많이 이용되고 있다. 본 연구에서는 HDS장치 유형 중에서 Vortex Screen 장치를 실험실 규모로 개발 및 제작하여 강우유출수 처리특성을 분석하였다. 강우유출수내 입자물질을 모의하기 위하여 실험에 사용한 시료는 합류식 하수관거의 맨홀 바닥 퇴적물질, 도로변 측구의 퇴적물질, 소각장 fly ash, polyvinyl chloride (PVC)분말 등의 시료를 대상으로 하였다. 유입유량의 변화를 주었을 때 처리장치 본체에서 약 2분이 경과한 후 안정된 상태에서 유입수와 유출수 시료를 동시에 채수하였다. 수면적부하율은 110∼1,550 $m^3/m^2$ day의 범위로 운전하였으며, 유입수 SS농도의 범위는 141~1,986 mg/L로 하였다. Vortex Screen을 이용하여 다양한 입경과 밀도들 가진 입자들을 대상으로 수면적부하율과 하부배출유량비를 운전조건으로 하여 처리특성을 분석한 결과 제거효율에 영향을 주는 인자 중, 월류유량에 대한 하부배출유량 비율($Q_U/Q_O$), $Q_U/Q_O$값이 10%에서 20% 증가 시 SS 제거효율은 6% 증가하는 특성을 나타내었다. 도시지역의 대표적인 입경을 가진 퇴적물질 125<$d_p$<300 ${\mu}m$를 대상으로 처리능을 분석한 결과 SS, COD 제거효율 범위는 각각 68.0~ 81.0%, 53.1~71.9%를 나타내었다. 수면적 부하율이 증가함에 따라 처리효율은 유입부 유도판을 설치한 경우가 설치하지 않은 경우보다 10~20% 향상되는 것으로 분석되었다.

• 상하수도학회지
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• 제25권4호
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• pp.471-478
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• 2011

A series of laboratory experiments carried out to investigate the particle separation efficiency and flotation characteristics using $CO_2$ bubbles. The primary objective of this study was to find out the feasibility of $CO_2$ bubbles as an applicable unit of flotation process in tap-water and wastewater treatment plant. The fundamental measurements were conducted to characterize the $CO_2$ bubble from the physical viewpoint in water including bubble size distribution and rising velocity under various operational conditions. In addition, the removal efficiency of solid was experimented using the lab scale plant applied $CO_2$ bubbles, namely the dissolved carbon dioxide flotation (DCF) process. The DCF process using carbon dioxide bubble, which is an advantage as the decrease and the reuse of Green-House gas, can be a promising technology as an water treatment process. On the other hand, the further research to decrease the bubble size distribution of $CO_2$ is required to enhance the particle separation efficiency.

• 설비공학논문집
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• 제15권8호
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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.

• 펄프종이기술
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• 제33권3호
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• pp.18-23
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• 2001

The effect of pulp consistency on the deinking properties in the ozone deinking of ONP was investigated in order to develop the environmentally friendly deinking method. The pulp consistency and ozone treatment time were varied for this purpose. Higher pulp consistency during ozone treatment gave better ink removal efficiency than the conventional deinking method. In was also found that the increase of pulp consistency can decrease the ozone treatment time which can meet the deinking quality. WRV of ozone deinked pulp obtained at 10% and 30% of pulp consistencies was lower than those of the conventional deinking method. However, the higher pulp consistency during ozone treatment improved WRV. Highest brightness was obtained at the ozone treatment condition of 30% pulp consistency and 10 minutes. The lower brightness at the other ozone treatment condition should be originated from the excessive decrease of ink particle size and then decrease of true ink removal efficiency. Scott bond was increased with the increase of pulp consistency and treatment time. However, the improvement of breaking length with ozone treatment was no significant.

• 한국입자에어로졸학회지
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• 제12권1호
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• pp.11-20
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• 2016

A large amount of wear dust generated during train operation is a major dust source in urban railway tunnels. To check possibility of a louver dust collector for the removal of dust in the railway tunnel, five louver dust collector models were designed and their performance was tested in a wind tunnel. JIS Z 8901 Class 8 dust was used as a test dust. Pressure drop and particle collection efficiency were evaluated with the face velocity ranging from 1 m/s to 4 m/s. At this low velocity range, particle collection efficiency of the louver dust collector was found to be insensitive to air velocity and design parameters. Pressure drop was under 40 Pa, and $PM_{10}$ and $PM_{2.5}$ collection efficiencies were approximately 50% and 30%, respectively.

• 대한건축학회논문집:구조계
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• 제34권12호
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• pp.73-82
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• 2018

The objective of this study was to evaluate particle collection performance of electrostatic precipitator (ESP) integrated with double skin façade in naturally ventilated residential buildings using numerical method. To evaluate the efficiency, computational fluid dynamics (CFD) simulation based on electric potential and Lagrangian method was applied. The CFD model was validated by comparing the simulated results with the experimental data including thermal characteristic of double skin façade (DSF) and particle removal characteristic of electrostatic precipitator. The validation results showed that the root mean square error (RMSE) between predicted values and measured values of velocity and temperature in intermediate space of DSF was 1.2%. The adequacy of ion space charge density and turbulent model were determined. The RMSE between predicted values and measured values of collection efficiency of ESP was 9.2%. In addition, the case study was performed to present the application of the numerical method based on validation results of ESP integrated with façade.