• 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.

• 수산해양기술연구
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• 제50권3호
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• pp.318-325
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• 2014

The main object of this study is to investigate the collection characteristics of wet-type rotating porous disk system experimentally. The experiment is carried out to analyze the pressure drop and collection efficiency for the present system with the experimental parameters such as system inlet velocity, stage number, tube diameter, inlet concentration, etc. In results, for the present system, at 5 stage and ${\upsilon}_{in}=1.8m/s$, the pressure drop becomes significantly lower as $64mmH_2O$ in comparison with that of the conventional wet type scrubber (Venturi scrubber, over $250mmH_2O$). The collection efficiencies increase with higher inlet velocity showing 92, 95.7, 98.4%, while $SO_2$ removal efficiencies decrease with increment of inlet velocity as 80, 65, 50% at ${\upsilon}_{in}=1.08$, 1.44, 1.8 m/s and tube diameter $D_t=10mm$, respectively. The present system is to be considered as an effective compact system for a simultaneous removal of particle/gas phase pollutants from marine diesel engines.

• Nuclear Engineering and Technology
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• 제28권4호
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• pp.397-404
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• 1996

The hydrogenated amorphous silicon (a-Si : H) holds good promise for radiation detection from its inherent merits over crystalline counterpart. For the application to alpha spectroscopy, the induced charge collection in a-Si : H pin detector diodes ons simulated based on a relevant non-uniform charge generation model. The simulation was peformed for the initial energy and the range of incident alpha particles, detector thickness and the operational parameters such as the applied reverse bias voltage and shaping time. From the simulation, the total charge collection was strongly affected by hole collection as expected. To get a reasonable signal generation, therefore, the hole collection should be seriously considered for detector operational parameters such as shaping time and reverse voltage etc. For the spectroscopy of alpha particle from common alpha sources, the amorphous silicon should have about 70${\mu}{\textrm}{m}$ thickness.

• Animal Bioscience
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• 제34권10호
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• pp.1632-1642
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• 2021

Objective: The hypothesis was that apparent ileal digestibility (AID), basal endogenous losses, and standardized ileal digestibility (SID) of amino acids (AA) are not affected by adding acid to collection containers or bags used to collect ileal digesta from pigs. Methods: Twenty-four growing barrows (initial body weight: 77.8±4.5 kg) that were fitted with a T-cannula in the distal ileum were fed diets for three 7-d periods. An N-free diet and 3 diets containing corn, soybean meal, or wheat middlings as the sole source of AA were used. Within each period, each of the 4 diets were fed to 6 pigs. Among the 6 pigs, digesta from 3 pigs were collected in bags containing no HCl, whereas 40 mL of 3 N HCl was included in the bags used to collect digesta from the remaining 3 pigs. Every other bag collected from each pig was emptied into a container without adding HCl, whereas the remaining bags were added to a container along with 40 mL of 3 N HCl for each bag. All digesta were stored at -20℃ immediately after collection. Data were analyzed using a model that included feed ingredient, HCl in bags, HCl in containers, and all 2-way and 3-way interactions as fixed effects. No 3-way interactions were significant, and data were, therefore, reanalyzed independently for each diet as a 2×2 factorial. Results: There were no interactions between adding HCl to collection bags and to containers, and no effects of adding HCl to collection bags or containers for AID, basal endogenous losses, or SID of most AA were observed. Conclusion: It is not necessary to add acid to digesta collection bags or collection containers if ileal digesta are stored at -20℃ immediately after collection.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.754-757
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• 2008

To maintain the indoor air quality, many ventilation systems and technologies have been developed in the highly insulated and air tight buildings. In this study, a porous construction material, which is applicable to passive ventilation system, is developed and measured the performances of the permeability and the resistance of water vapor, and the dust collection efficiency. The average coefficient of water vapor permeability shows $3.6\;g/m^2{\cdot}h{\cdot}mmHg$, which is slightly higher than Hanji ($2.4{\sim}3.2\;g/m^2{\cdot}h{\cdot}mmHg$) and the average water vapor resistance factor shows $0.303\;g/m^2{\cdot}h{\cdot}mmHg/g$, which is slightly smaller than Hanji($0.309{\sim}0.315\;g/m^2{\cdot}h{\cdot}mmHg/g$). The pressure drop of the porous construction material is smaller than the HEPA filter and the minimum dust collection efficiency shows 82.8% in the range of $2{\sim}9\;cm/s$.

• 동력기계공학회지
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• 제18권3호
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• pp.42-50
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• 2014

The main object of this study is to investigate the collection characteristics of wet-type multi-layered and multi-staged porous plate system experimentally. The experiment is carried out to analyze the characteristics of pressure drop and collection efficiency for the present system with the experimental parameters such as water spray, inlet velocity, stage number and inlet particle concentration, etc. In results, for the present system of wet-type, the pressure drop represents 158 $mmH_2O$ higher 3% than that in dry-type at 5 stage and $v_{in}$=3.53 m/s. In case of 5 stage, $v_{in}$=3.53 m/s and water spray 250 ml/min, the collection efficiency of the present system becomes significantly higher as 99.7% comparing to that of the conventional wet-type scrubber. Additionally, for 5 stage and 250 ml/min, $SO_2$ removal efficiencies decrease with the increment of inlet velocity representing 75.0, 62.5, 50.0%, at $v_{in}$=2.12, 2.82, 3.53 m/s, respectively.

• 대한환경공학회지
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• 제33권8호
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• pp.598-605
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• 2011

본 연구의 주 목적은 다층 다단 다공성 시스템에 편극전하 방식을 부가하여 본 시스템의 집진특성을 실험적으로 해석하는데 있다. 본 시스템의 압력손실 및 집진효율 특성 해석을 위해 실험은 인가전압, 시스템 유입유속, 유입농도 및 stage 수 등의 실험적 변수들에 의해 수행된다. 실험결과, 기류유입 시 유입유속 $v_{in}$ = 3.11 m/s에서 단(stage) 수 변화($1{\rightarrow}5$단)에 따라 압력손실은 $18{\sim}134mmH_2O$를 나타낸다. 인가전압 0 kV 및 기류유입이 없을 때, 시스템 유입유속 $v_{in}$ = 2.58 m/s인 경우 5 stage에서 집진효율은 92.5% 인 데 비해, 동일 유속에서 플레이트 별 편극전하(alternating polarization charge-applied voltage 2.5 kV) 및 기류유입 시스템인 경우 5 stage 효율은 98.5%로 전자에 비해 6% 정도 매우 높은 효율 상승을 보인다.

• 수산해양기술연구
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• 제51권4호
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• pp.545-552
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• 2015

The main object of this study is to investigate the collection characteristics of an electro-static multi-staged impaction system, experimentally. The experiment is carried out to analyze the characteristics of pressure drop and collection efficiency for the present system with the experimental parameters such as the inlet velocity, stage number, applied voltage and shape of discharge electrode, etc. In results, the pressure drop is shown below $148mmH_2O$ lower than that of the conventional bag filter at inlet velocity 3.46 m/s and 5 stage. For 5 stage, the collection efficiencies are to be 97.4, 99.0% with the applied voltage 0 kV at the inlet velocity 2.07, 3.46 m/s, while 98.4, 99.9% with 40 kV of a sharp edge discharge electrode. Additionally, the present system is to be considered as an effective compact system for a removal of particulate pollutants from marine diesel engines due to much higher collection efficiency and appropriate pressure drop.

• 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.

• 한국환경과학회지
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• 제10권5호
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• pp.351-358
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• 2001

The main purpose of this study was to investigate the characteristics of cylindrical electrostatic precipitator with centrifugal effect in viewpoints of pressure drip and collection efficiency, experimentally. The experiment was carried out for the analysis of current-voltage, pressure drop and collection efficiency with various experimental parameters such as the applied voltage, inlet velocity, inlet size and inlet type(upper and bottom), etc. In the results, the pressure drops were estimated as 27~54, $34~63mmH_2O$ for inlet size $15mm{\tiems}30mm$ and $30mm{\tiems}60mm$, respectively. The collection effeciencies were shown over 90% with the small inlet size($15mm{\tiems}30mm$) for the applied voltage 40kV, inlet velocity(15~21m/s), and 51~89% with the large inlet size ($30mm{\tiems}60mm$). Moreover, in the applied voltage 0kV and inlet size $15mm{\tiems}30mm$, the collection efficiency induced by centrifugal force was represented as about 35% with inlet velocity 15 - 21m/s.