• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권7호
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• pp.444-451
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• 2004

Conventional magnetic levitation systems could show unsatisfactory performance under air-gap disturbance due to rail irregularities. In this paper, we propose a feedback control system with discrete Kalman filter for air-gap disturbance attenuation. It is shown that excellent system performance can be obtained with the use of discrete Kalman filter, and that results from experiments agree well with those of simulations.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.436-441
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• 2006

In recent European telecommunication base transceiver stations(BTS) a membrane laminated air filter is reported to replace a heat exchanger in order to cool internal digital units of BTS. The concept of using the air filter is for the direct ambient cooling(DAC) of BTSs without heat loss generally found ill the heat exchanger type BTS. In the present study, a performance evaluation experiment was conducted to investigate the pressure drop characteristics with dust loading and the particle collection efficiency of the air filter for the DAC of BTS.

• 한국생산제조학회지
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• 제19권4호
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• pp.548-552
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• 2010

The air suction filter of the power plant decrease the dust and impurities of suction air that reduce the life and efficiency of the boiler. The suction efficiency of the air filter falls with the dust and impurities when the time of use comes to be long. Therefore, the various contaminant of the filter must remove periodically. This paper presents a developed quick exhaust valve to use in the thermo-electric power plant. to removing contaminants on the filter, the blowing is done shortly by air pressure. The Air flowed out to the out side from the inside of the filter. The performance test of the developed valve is done by making a test-bench according to JIS and KS standards. The efficiency is found higher than the existing related valve.

• 환경위생공학
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• 제24권3호
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• pp.16-27
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• 2009

In this paper, I examined the level of fine dust in medical institutions, educational institutions and multi-purposed facilities to grasp the exact state of the present, and decided the level of air-borne particulate(KSM ISO Standard and ISO Standard 14644-1). We compared new proposed cleaner equipped with HEPA Filter with general cleaner and analyzed the rate of removal according to height, air volume and the equipment with the compulsive air intake. Through this comparison, I reached the conclusion as follows: 1. According to the examination, the fine dust of medical institutions, educational institutions and multi-purposed facilities in Kwang Ju is class 9. 2. The filter used in general cleaner on the market is that of HEPA-type, and its removal efficiency for fine particles($0.3{\sim}0.5{\mu}m$) is very low. 3. In the removal efficiency of new proposed cleaner equipped with HEPA Filter, the higher it is, the better, especially more than 180cm in height. 4. In case it is operated for 5 minutes under the condition of the space of $9.4m^{3}$ and the maximum air volume equipped with two induction pipes, we can keep the air cleanness level of 5 ~ 6. 5. To maintain the air cleanness for a long time, if we first operate for 5 minutes at maximum air volume and then operate at medium maximum air volume, we can keep the air cleanness with low energy.

• 대한설비공학회지:설비저널
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• 제15권2호
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• pp.123-143
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• 1986

• 설비공학논문집
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• 제6권4호
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• pp.417-426
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• 1994

Filter media performance was evaluated using monodisperse NaCl particles with Differential Mobility Analyzer and Ultrafine Condensation Particle Counter. Low or medium performance filters show that the most penetrating particles size(MPPS) is around $0.3{\mu}m$ in diameter and is shifted to smaller sizes as the filter face velocity increases. However, HEPA and ULPA filters show MPPS is around $0.15{\mu}m$ in diameter and is also shifted to $0.1{\mu}m$ in diameter as the face velocity increases. In case of electret filter, the MPPS is found around $0.04{\mu}m$ region for Boltzmann charge equilibrium particles. There is a tendency of strong collection efficiency decrease for large particles as the face velocity increases on the contrary to the other filters. One of the medium performance filter efficiency was compared with filtration theory and the good agreetment was found in the experimental range.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.739-744
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• 2009

The filter has long been used in purification processes for indoor air quality. To determine the deodorization effect of several filter materials in a full-scale air-handling system, the present study has been carried out using a wind tunnel equipped with a heat exchanger and various filter materials, such as commercial fabric, activated carbon(AC) and silver nano-particles attached to activated carbon(Ag-AC). The experiment was conducted using an odor substance with ammonia, acetaldehyde, acetic acid. The results obtained indicate that odor substance is substantially decreased on the moisture condensation on the surface of the heat exchanger. The fabric filter has no effect for removal of odor substances. The deodorization efficiency is found to be approximately 7% in the AC filter, while the deodorization efficiency is increased up to 10% using the Ag-AC filter.

• 한국입자에어로졸학회지
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• 제15권4호
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• pp.173-182
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• 2019

Since airborne viruses have been known to aggravate indoor air quality, studies on the development of anti-viral air filter increase recently. In this study, the pressure drop and anti-viral efficiency of TiO₂ coated ceramic ball filter were evaluated. After the filter being inserted into a commercial room air cleaner, chamber test with aerosolized bacteriophage MS2 was performed. The porosity of TiO₂ coated ceramic ball filter was 0.85, and pressure drop was about 13 Pa for 1 m/s of air velocity. The anti-viral efficiency was about 93% when the reaction time was 25 minutes in a 1 ㎥ chamber.

• 한국분무공학회지
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• 제12권2호
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• pp.86-93
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• 2007

There is a growing interest to develop an eco-friendly air cleaner with high performance through a remanufacturing process. Two kinds of polyurethane filter media, a coarse (Filter-A) and a fine filter media (Filer-B), are used in this study to protect a vehicle engine from airborne particles. In order to improve the collection performance of the filters (Filter-A, Filter-B), an oil coating technology on the filter surface was introduced. As a result, inertial force is a dominant collection mechanism for a dry filter media, so that collection efficiency increases with increasing filtration velocity. However, intra-structure change of an oil-coated filter media influences on the collection mechanism, which shows a non-linear collection efficiency curve in terms of filtration velocity. The result shows that the developed filter media are eco-friendly and effective to protect a vehicle engine from airborne particles especially at low filtration velocity.

• 한국결정성장학회지
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• 제29권6호
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• pp.276-282
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• 2019

본 연구의 목적은 공기청정기의 극세필터(프로필터), 집진필터, 헤파(HAPA-High Efficiency Particulate Air)필터, 탈취필터 등을 사용하는 일반적인 필터의 구조를 분석하고 초미세먼지, 유해가스 및 살균 정화성능을 향상시킬 수 있는 새로운 형태의 공기정화 필터 디자인을 제시하는 것이다. 기존 단계적 여과 필터 형태에 광촉매 필터 시스템을 추가하는 방법으로 연구하였으며, 광촉매 필터는 좌우측의 UV-LED 설치 프레임과 광촉매 코팅 허니컴(honeycomb)프레임 3단 결합구조의 디자인으로 제안했다. 광촉매 필터의 살균소독 효과에 대해서는 향후 연구가 필요하며, 본 연구에서는 공기청정기에 광촉매 필터 적용 및 구조에 대하여 보고하고자 한다.