• Journal of Animal Environmental Science
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• v.9 no.1
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• pp.19-26
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• 2003

This study was carried out to investigate the collecting efficiency of cyclone deduster installed in weaned piglet building in third weeks of age. There are two peaks of high level of dust concentration in piglet house at the time of 09:00~10:00(5,322$\mu g/m^3$) and 19:00~20:00(6,763$\mu g/m^3$), but the peaks of dust concentration in the building used cyclone deduster was decreased to 3,614.8 and 2,229.5$\mu g/m^3$, respectively. Collecting efficiency of total suspended particulate(TSP), particulate matter less than 10$\mu\textrm{m}$(PM 10) and particulate matter less than 2.5$\mu\textrm{m}$(PM 2.5) in weaned piglet building used in cyclone deduster was 38.3%, 32.5, 21.8, respectively. Aerial dust in weaned piglet building by number basis in the range of 0.745~1.08$\mu\textrm{m}$ was 53.5%. But dust distribution over 10$\mu\textrm{m}$ in volume basis was 82.8% and 86.2%. Crude protein of dust was 25.9~32.7%, and it was higher than feed crude protein(22.0%). Heavy metal concentration of dust was also high level compare to that of feed.

• Particle and aerosol research
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• v.13 no.4
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• pp.151-158
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• 2017

Electrostatic precipitator is widely used to remove particulate matters in indoor air and industrial flue gas due to low pressure drop and high collection efficiency. However, it has a low collection efficiency for the submicrometer sized particles. Electrospraying is a potential method to increase the particle charging efficiency, which results in increased collection efficiency. Although particle charging efficiency is highly dependent upon droplet size, the effective measuring method of the droplets is still uncertain. Tap water was electrosprayed in this study, and the images of electrosprayed droplets were taken with a high speed camera coupled with several visualization methods in order to measure the droplets size. The droplet size distribution was determined by an image processing with an image-J program. As a result, a droplet measured by a laser visualization, had a half size of that by a Xenon light visualization. In addition, the experimentally measured droplet sizes were a good agreement with the predicted values suggested by $Fern{\acute{a}}ndez$ de la Mora and Loscertales(1994).

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.706-714
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• 2020

Currently, 90 % of the world's population breathes air with a fine dust content exceeding the World Health Organization's annual average exposure limit (10 ㎍/㎥). Global efforts have been devoted toward reducing secondary pollutants and ultra-fine dust through regulations on nitrogen oxides released over land and sea. Domestic efforts have also aimed at creating clean marine environments by reducing sulfur emissions, which are the primary cause of dust accumulation in ships, through developing and distributing environment-friendly ships. Among the technologies for reducing harmful emissions from diesel engines, electrostatic precipitator offer several advantages such as a low pressure loss, high dust collection efficiency, and NOx removal and maintenance. This study aims to increase the durability of a ship by improving equipment quality through failure mode effects analysis for the preventive maintenance of an electrostatic precipitator that was developed for reducing fine dust particles emitted from the 2,427 kW marine diesel engines in ships with a gross tonnage of 999 tons. With regard to risk priority, failure mode 241 (poor dust capture efficiency) was the highest, with an RPN of 180. It was necessary to determine the high-risk failure mode in the collecting electrode and manage it intensively. This was caused by clearance defects, owing to vibrations and consequent pin loosening. Given that pin loosening is mainly caused by vibrations generated in the hull or equipment, it is necessary to manage the position of pin loosening.

• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.149-156
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• 2013

In this paper, Commercial program, STAR-CCM+, was used for computer simulation. And also Multi Inner Stage(MIS) cyclone which especially designed for the real experiments of particle removal efficiency. Under negative pressure condition of outlet, computer simulation was performed to predict the removal efficiency for $5{\mu}m$ and $10{\mu}m$ particles by using a turbulence model and lagrangian method. The simulation results are 55.7% and 64.1% for $5{\mu}m$ and $10{\mu}m$ particles, respectively. To compare the simulation results with the actual test of MIS cyclone, we generated the $SiO_2$ particles by heat reactor. Although removal efficiency of actual tests is 63~76% at different flow rate, the size of $SiO_2$ particles which confirmed by SEM(scanning electron microscope) and WAPS(wide range aerosol particle spectrometer) is too small(15~30nm) to compare each results. And so the alternative experiments were performed by using commercial alumina particles ($5{\mu}m$, $10{\mu}m$ and $20{\mu}m$). It was shown that the actual removal efficiency, 76~95%, from MIS cyclone is higher than simulated one.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2009.10a
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• pp.563-565
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.215-216
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.427-428
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• 2000

공기 여과 장비에 주로 쓰이는 섬유층 여과기(fibrous filter)는 다양한 장비에 널리 쓰이고 있다. 섬유층 여과기는 이를 구성하는 섬유(fiber)의 직경, 표면 조도, 그리고 이들로 해서 나타나는 공극률, 하전여부, 등 여러 가지 필터의 특성에 따라 다양한 포집양상(Deposition Morphology)을 보인다. 제조 공정에 따라 달라지는 특성을 가진 필터는 여과 과정을 거치면서 입자가 퇴적되고 압력강하가 증가하여 필터의 수명이 다하게 된다. (중략)

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.369-371
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• 2008

본 논문은 철강공장의 냉각수 처리 시스템에서 고로 집진수를 대상으로 한 응집교반실험을 실시한 결과, 주기적인 관 갱생작업(산세척)과 분산제의 주입이 필요하며, 음이온 고분자응집제에 양이온 고분자응집제를 첨가하여 사용할 경우에 탁도 제거측면에서 우수하였다. 급속교반 후 완속교반을 적용할 경우 급속교반 후 침전보다 탁도 제어 효과가 더 우수한 것으로 관찰되었으므로, 침전지의 처리효율을 증가시키기 위해서는 급속교반과 완속교반이 동시에 필요하였다.

• Particle and aerosol research
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• v.11 no.2
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• pp.47-55
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• 2015

This study compares the results of collection efficiency of difference gas temperature in cyclone dust collector. The previous researcher's experiment results were used to confirm the reliability of CFD(Computational Fluid Dynamics) model. Based on this verified CFD model, we extended the analysis on the cyclone dust collectors. In CFD study, we used RNG k-epsilon model for analysis of turbulence flow, fluid is air, the velocity at inlet is 10 m/s, the temperature of air is $20^{\circ}C$, $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$, $600^{\circ}C$ and $1000^{\circ}C$. As the temperature decreases, the average velocity of outer vortex and collection efficiency is increased, showed the highest collection efficiency at $20^{\circ}C$. It can be inferred smooth flow in cyclone dust collector is difficult because air viscosity increases as temperature increases. The power required at $1000^{\circ}C$ is almost 18 times greater than that of $20^{\circ}C$ to get the similar collection efficiency.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.508-511
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• 2011

Dust released from the rotating timber cutting process causes various kinds of diseases as well as safety issues. Although there were lots of efforts to reduce the amount of dust by installing large-sized dust collectors or by using expensive high-quality cutters, they proved to be not so effective. In this study we want to modify and improve the design of the rotary cutter system to prevent dust from being released to the environment as possible by using computational fluid dynamics (CFD) analysis. We have developed CFD models of the conventional cutter and several design modifications. Through the CFD analysis the characteristics of the air flow was predicted, and then the behavior of dust produced during the cutting process was analyzed for different designs. The most efficient design feature to capture dust inside the cutter as much as possible was chosen based on the CFD analysis results. Finally the prototype of the ratary saw machine was constructed and tested to check the dust capturing efficiency, which result is reasonably consistent with the predicted performance through the CFD analysis.