• Title/Summary/Keyword: HEPA 필터

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Characteristics of HEPA Filter Waste Compactor Developed by KAERI and Comparison with Japan's and U.S.A's Compactors (KAERI 개발 HEPA 필터폐기물 압축처리장치 특성 및 일본, 미국 압축처리장치와의 비교)

  • 이강무;안섬진;배상민;손종식;홍권표;김홍태
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.149-157
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    • 2003
  • The HEPA filter waste (Hexahedron, $610{\times}610{\times}292mm$, 20kg), which is used for the ventilation system in the nuclear industries, has relatively large volume to compare with it's weight. Due to the large volume of HEPA filter waste, it needs the large storage and/or disposal space and managing cost during the long period of storage and management. Many countries use the compactor to reduce the volume of HEPA filter waste. On this paper we introduce the new type compactor developed by KAERI with the characteristical comparison to the Japan's and U.S.A's compactors.

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HEPA Filter Tests Using PLS and Composite Nanospheres (PLS 및 복합 나노구체를 이용한 HEPA 필터 시험)

  • Hwang, Min-Jin;Sung, Dong Chan;Moon, Hee
    • Applied Chemistry for Engineering
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    • v.24 no.4
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    • pp.357-362
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    • 2013
  • Monodispersed polystyrene latex spheres (PLS) and PS-MPS/silica composite nanospheres were used to test high efficiency particulate air (HEPA) filters. Prior to filter tests, all nanospheres used in this work were characterized by measuring their average particle diameters and coefficients of variation (CV) for assessing them as artificial dusts. The average particle sizes of PLS and composite nanospheres could be well controlled in the range of 100~300 nm well by changing reaction temperature and the amount of a stabilizer during emulsion polymerization. The CV of all nanospheres were also in the range of 3~7%, lower than 15% that is the criterion for monodispersed particle distributions. Furthermore the results of HEPA filter tests show that all nanospheres used were quite proper as artificial dusts for testing air filters.

Production of air purification verification system using moss (이끼를 활용한 공기정화 검증 시스템 제작)

  • Ahn, Dohyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.587-591
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    • 2019
  • Fine dust aerated in the atomsphere penetrates our lungs and blood lines through respiratory. Recent fine dust problems in Korea leads to development of various air purifiers. The researchers used this to study systems that could replace chemical filters. In order to compare the effect of the reduction of moss and conventional chemical filter(Hepa), a 1 cubic meter cube was prepared and the amount of the concentration of fine dust reduction was compared under controlled environment. Under the high concentration of fine dust, a test was done to figure out the reduction rate of the fine dust concentration by using air purification system with moss, hepa, and no filter. The air purification system(moss, hepa, and no filter) were operated 90 times in total, 30 times each. The test explains that the reduction of the fine dust amount and the rate of fine dust concentration. The results illustrate that the reduction of the amount fine dust was 138.93 after using air purification system with moss filter. In contrast, the usage of air purification system with hepa filter reduced the amount of fine dust to 76.57. And the air purification with no filter shows that the slight reduction of fine dust amount at 0.10. In the rate of fine dust concentration, moss filter was significantly higher than that of hepa, no filter (0.2379, 0.1298 and 0.0063 each). The results have confirmed that moss is effective in reducing fine dust concentration, and it is expected that with further improvement it can be used as a means to replace or supplement existing chemical filters in air purifier.

방사성환기설비 운전에 있어서의 부압변동 요인 및 대응 방안

  • 이강무;이범철;이영희;김태국;손종식;홍권표;김홍태
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.334-335
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    • 2004
  • It is important that the contaminated air is not revealed to the outside of the facility. The inside of the facility should be classified into several zones according to the radioactivity and each zone should maintain tile differential negative pressure between the zones also. It is not easy to equilibrate the pressure during the operation. On the normal operation, the clogging of the HEPA filter and the opening of the doors/shutters influence very much. We could maintain the differential negative pressure between the zones by the constant watching and periodical replacement of the filters.

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Evaluation of Particulate Matter Removal Rate according to Filter Type and Thickness of Total Heat Exchanger in Apartment Houses (공동주택 전열교환기 필터종류 및 두께에 따른 미세먼지 제거율 평가)

  • Song, Yong-Woo
    • Land and Housing Review
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    • v.11 no.4
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    • pp.93-98
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    • 2020
  • This study examined the particulate removal performance of three different types of air filters inside a heat exchanger. Of interest was the ability of each filter type in reducing the transmission of outdoor particulate matter of PM10 from entering an apartment while the heat exchanger was in operation. The study tested one commonly used medium filter (E11 grade) and two HEPA filters (H13 grade) of different thicknesses. Two different concentrations of particulate matter were used in the experiment to address different ambient air quality conditions in Korea, 32.75 ㎍/㎥ and 67.26 ㎍/㎥. Study results indicated that under the particulate matter concentration of 32.75 ㎍/㎥, all three filters were capable of removing more than 95% of the fine dust. However at a particulate matter concentration of 67.26 ㎍/㎥, the medium E11 grade filter was only able to remove about 90% of the particulates whereas the HEPA H13 grade filters were able to remove 95% or more of the particulates. The thicker HEPA filter (40T) was also more effective in removing particulates than the thinner HEPA filter (20T) by about 1.6 to 3 percentage points. Based on the findings of this study, it is recommended that HEPA filters of 20T thickness or greater be used during the high air pollution seasons of winter and spring in Korea while medium filters can be used during the other seasons to reduce outdoor air pollution transmission indoors.

Changes in microbial phase by period after hepa filter replacement in King oyster(Pleurotus eryngii) mushroom cultivation (큰느타리 재배사에서 헤파필터 교체 이후 기간에 따른 미생물상 변화)

  • Park, Hye-Sung;Min, Gyong-Jin;Lee, Eun-Ji;Lee, Chan-Jung
    • Journal of Mushroom
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    • v.18 no.4
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    • pp.398-402
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    • 2020
  • This study was conducted to set up a proper replacement cycle of High Efficiency Particulate Air (HEPA) filters by observing the microbial populations in the air of the cultivation house of Pleurotus eryngii, before and after HEPA filter replacement at different periods. The density of bacteria and fungi in the air during each cultivation stage was measured using a sampler before the replacement of the HEPA filter. The results showed that airborne microorganisms had the highest density in the mushroom medium preparation room, with 169.7 CFU/㎥ of bacteria and 570 CFU/㎥ of fungi, and the removed old spaun had 126.3 CFU/㎥ of bacteria and 560 CFU/㎥ of fungi. The density of bacteria and fungi in the air at each cultivation stage before the replacement of the HEPA filter was 169.7 CFU/㎥ and 570 CFU/㎥, and 126.3 CFU/㎥ and 560 CFU/㎥, during the medium production and harvesting processes, respectively. After the replacement of the HEPA filter, the bacterial density was the lowest in the incubation room and the fungal density was the lowest in the cooling room. The microbial populations isolated at each period consisted of seven genera and seven species before the replacement, including Cladosporium sp., six genera and six species after 1 month of replacement, including Penicillium sp., 5 genera and 7 species after 3 months of replacement, including Mucor plumbeus, and 5 genera and 12 species, 5 genera and 10 species, and 5 genera and 10 species, 4, 5, and 6 months after the replacement, respectively, including Penicillium brevicompactum. During the period after replacement, the species were diversified and their number increased. The density of airborne microorganisms decreased drastically after the replacement of the HEPA filter. Its lowest value was recorded after 2 months of replacement, and it increased gradually afterwards, reaching a level similar to or higher than that of the pre-replacement period. Therefore, it was concluded that replacing the HEPA filter every 6 months is effective for reducing contamination.

Performance Test of Air Filter Media (필터여재의 성능평가)

  • Ahn, K.H.;Bae, G.N.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.6 no.4
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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.

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