• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1423-1428
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• 2003

We investigated the amount of the toxic gases emitted from the Electrostatic Precipitators(ESPs), which were currently used by indoor air cleaners. We used the wire-to-plate(WTP) type and the needle-to-plate(NTP) type corona discharger in our study. Using the voltage, the polarity of wire, the number of needles of NTP as the input variables, we studied the characteristic of Ozone and $NO_x$ generation in the ESPs. As the results, we found out that the concentration of Ozone, $NO_2$ and $NO_x$ is increased, but the amount of NO is decreased with increasing the voltage and the number of needles. And we knew that the generation rate of ozone and $NO_x$ is very related with the corona region.

• 한국대기환경학회지
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• 제25권1호
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• pp.38-45
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• 2009

Since the seventies and the oil crisis, energy-saving measures have led to a reduction in the ventilation of room. The use of synthetic materials which emit various chemical substances had led to an increase in the concentration of indoor pollutants. "Sick building syndrome (SBS)" and "Sick house syndrome (SHS)" are worldwide problems. Also, the number of complaints about indoor air pollution caused by VOCs (Volatile organic compound) and HCHO (Formaldehyde) has increased. It is important that evaluating and understanding emission of indoor air pollutant from building materials. The object of this study was to evaluate emission test method for flooring such as wood based flooring, carpet tile, rubber tile, PVC sheet and tile, and to determine emission of TVOC and form-aldehyde. The quantity of TVOC and carbonyl compounds emission were sampled and measured by Tenax TA and gas chromatography/mass spectrometry (GC/MSD), 2,4-DNPH cartrige with ozone scrubber and high performance liquid from flooring. The TVOC concentration emitted from carpet tile was ($7.419\;mg/m^2 h$) the highest among 5 groups of test materials. In wood based flooring and PVC tile, the emitted concentration of toluene was high. And the dodecane emission was highest in carpet. The concentration of TVOC decreased by an increase in emission test period. After 7 days, the concentration of TVOC from floorings were about 50% below of the concentration at the first day. TVOC emission from wood based flooring, carpet tile, rubber tile, PVC sheet and tile were decreased in 28 days and remained steady after about 15 days. The concentration of formaldehyde emission from floorings showed extremely low.

• 조명전기설비학회논문지
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• 제22권12호
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• pp.176-182
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• 2008

본 연구는 실내공기와 상수의 수질개선을 위하여 소형 평판형 오존발생기(plate-type ozonizer : PTO)를 개발하여 그 특성을 규명한 논문이다. 평판전극의 크기, 개수 및 배치에 따라 다양한 형태의 오존발생기가 고안되었다. 각 형태의 오존발생기의 방전면적은 60[$cm^2$]로 동일하며 방전전력은 최대 30[W]이다. 주요 연구 대상은 방전전력-오존생성농도 특성, 방전전력-오존생성수율 특성, 유량-오존생성농도 특성 및 유량-오존생성수율 특성이다. 오존생성특성은 PTOL-P가 가장 우수하게 나타났으며, 나머지 3종류의 오존발생기($PTO_{P-P}$, $PTO_{C-P}$, $PTO_{T-P}$)에서는 유사한 결과를 얻을 수 있었다.

• 한국산학기술학회논문지
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• 제17권5호
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• pp.17-25
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• 2016

본 연구에서는 지하역사와 지상역사에서의 실내공기질을 측정하고, 외부 공기에 의한 영향 정도를 확인하고자 하였다. 측정된 물질은 '실내공기질 관리법'상에서 유지기준과 권고기준으로 지정된 항목 중, 농도가 검출되지 않은 석면을 제외한 미세먼지($PM_{10}$), 이산화탄소($CO_2$), 일산화탄소(CO), 이산화질소($NO_2$), 폼알데하이드(HCHO), 오존($O_3$), 총부유세균(TAB), 총휘발성유기화합물(TVOC), 라돈 등 9종이다. 또한 미세먼지, 이산화질소, 오존 등 세 가지 물질은 I/O ratio를 통해 외기에의한 영향을 확인하였다. 공기질 측정결과 지상역사에 비해 지하역사에서 미세먼지, 폼알데하이드, 총휘발성유기화합물, 이산화질소, 라돈 등이 높은 농도로 검출되었으며, 이는 지하역사 내부에 그 오염물질의 발생요소가 존재하기 때문으로 판단된다. 오존 농도는 지상역사에서 지하역사보다 높은 농도로 검출되었으며, 특히 외부로 노출되어있는 지상역사 승강장에서 높은 농도를 보임으로써 외기 유입에 의한 영향이 있는 것으로 확인되었다. 따라서, 외기에 의한 영향을 받는 오염물질은 역사의 기계환기시 제거 과정을 거쳐 오염물질의 실내유입을 차단하고, 지하역사에서 기인한 미세먼지 등의 물질들은 실내에서 그 발생원에 따른 별도의 처리가 필요할 것으로 판단된다.

• 한국입자에어로졸학회지
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• 제4권1호
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• pp.9-20
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• 2008

The effect of light intensity on the ozone formation and the aerosol number concentration during the photochemical reactions of ambient air was investigated in an indoor smog chamber. The smog chamber consists of a housing, 64 blacklights, and a $2.5-m^3$ reaction bag made of Teflon film. The bag was filled with the unfiltered ambient air in Seoul from January 10 to March 18, 2002. In this work, the photolysis rate of $NO_2$, $k_1$ was used as an index of light intensity. Three levels of light intensity were controlled by changing the number of blacklights turned on among 64 blacklights: $0.29min^{-1}$ (50%), $0.44min^{-1}$ (75%), $0.57min^{-1}$ (100%). The ozone concentration increased rapidly within 10 minutes after irradiation irrespective of light intensity, thereafter it increased linearly during the irradiation. The ozone production rate seems to be dependent on both the light intensity and the quality of ambient air introduced into the reaction bag. The change in aerosol number concentration also depended on both the light intensity and the ambient air quality, especially aerosol size distribution. Based on the initial ambient aerosol size distributions, the photochemical potential for aerosol formation and growth is classified into two cases. One is the case showing aerosol formation and growth processes, and the other is the case showing no apparent change in particle size distribution.

• 한국대기환경학회지
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• 제21권1호
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• pp.15-26
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• 2005

An experimental investigation of the gas-phase photooxidation of toluene-NO$_{x}$-air mixtures at sub-ppm concentrations has been carried out in a 6.9 m3, indoor smog chamber irradiated by blacklights. Measured parameters in the toluene-NO$_{x}$ experiments included $O_3$, NO, NO$_2$, NO$_{x}$, CO, SO$_2$ toluene, and air temperature. The initial toluene concentration ranged from 225 ppb to 991 ppb and the initial concentration ratio of toluene/NO$_{x}$ in ppbC/ppb was in the range of 5～20. It was found that the variation of gaseous species with irradiation time caused by the photooxidation of toluene-NO$_{x}$-air mixtures depended on the initial toluene concentration for similar concentration ratio of toluene/NO$_{x}$. The dependency of initial toluene concentration on the photooxidation of toluene-NO$_{x}$-air mixtures for toluene/NO$_{x}$=5～6 seemed to be opposite to that for toluene/NO$_{x}$=10～11. The arriving time at maximum ozone concentration depended on both initial toluene concentration and initial concentration ratio of toluene/NO$_{x}$. However, the maximum concentration of ozone formed by photooxidation depended only on the initial toluene concentration.luene concentration.

• 대한기계학회논문집B
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• 제27권10호
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• pp.1442-1449
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• 2003

We investigated the amount of the toxic gases emitted from the Electrostatic Precipitators(ESPs), which are currently used as the indoor air cleaners. The existing wire-to-plate(WTP) and neddle-to-plate(NTP) types of ESP designs are considered as the experimental corona dischargers. Using the voltage, the polarity of wire, the number of needles of NTP as the input variables, we studied the generation characteristics of ozone and $NO_{x}$ and the particle removal efficiency in the ESPs. As the results, we found out that the concentration of ozone, $NO_{2}$ and $NO_{x}$ is increased with increasing the voltage and the number of needles, but the amount of NO is decreased. And we observed that the generation rates of ozone and $NO_{x}$ are mainly related with the corona region through the photographs. Finally the experimental results showed that the particle removal efficiency of ESP with WTP type charger is more superior to that with NTP type chargers at the same voltage.

• 조명전기설비학회논문지
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• 제23권5호
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• pp.80-87
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• 2009

최근 오존은 그 효용성을 인정받아 다양한 분야에서 사용되고 있으며, 그 수요 또한 계속 증가하는 추세이다. 이에 다양한 종류의 오존발생기가 연구되고 있다. 본 연구는 실내공기와 상 하수도의 수질개선을 위하여 cascade형 평판전각 오존발생기(plate-type ozonizer : PTO)를 개발하여 그 특성을 조사한 논문이다. 평판전극의 크기, 개수 및 배치에 따라 4가지 형태의 오존발생기를 설계하였다. 각 형태의 오존발생기의 방전 면적은 22,400[$mm^2$]로 동일하며 방전전력은 최대 40[W]이다. 각 오존발생기의 오존생성량, 오존생성농도, 오존생성수율 특성을 연구한 결과, 8개의 평판전극이 cascade형으로 배치된 오존발생기(PTO-4)의 오존생성특성이 가장 우수하게 나타났다.

• 조명전기설비학회논문지
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• 제25권7호
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• pp.83-91
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• 2011

Even if smoke, fumes, mist or dust particles are removed by electrostatic precipitators (ESPs), the occurrence of ozone, which is harmful to human body, has to be severely restricted in the indoor environments of hospitals, offices, and workshops. Therefore, the two-stage ESP generating positive corona at the ionizer is typically used because it creates less ozone than the two-stage ESP generating negative corona at the ionizer. In order to predict the collection performance and the optimal design of the two-stage ESP applied to positive high-voltage, particle concentration is experimentally investigated in this paper. In addition, particle motion within the collector section is also numerically analyzed. The positive corona discharge current of the ionizer is found to be affected by the applied voltage in the collector section but less so by the particle concentration. Particle concentration shows a minimum near the high voltage electrode of the collector section. The minimum value of the collection efficiency is almost proportional to gas velocity. When the collector length decreases, the minimum value of the collection efficiency increases. Charged particles entering the collector region are linearly deflected towards the grounded plate by an electric field. From the above experimental and numerical results, two empirical equations on the concentration ratio and the collection efficiency are derived, and are in good agreement with the experimental data.

• 실내환경 및 냄새 학회지
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• 제17권4호
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• pp.396-403
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• 2018

In this study, volatile organic compounds (VOCs) emitted from printing industries were analyzed, and an inorganic adsorbent, ${\gamma}-alumina$, was selected for the effective control of the VOC emissions. Printing processes commonly require inks, thinners, and cleaners, and they were mixed organic solvents containing aromatic compounds, ketones, and alcohols. Therefore, toluene, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA) were selected as model compounds for this study. The adsorptive properties using ${\gamma}-alumina$ were determined for the model compounds. Both batch isotherm and continuous flow column tests demonstrated that the adsorption capacity of MEK and IPA was 3~4 times higher than that of toluene. The column test performed at an inlet toluene concentration of 100 ppm showed that an 80% breakthrough for toluene was observed after 3 hours, but both MEK and IPA were continuously adsorbed during the same time period. A numerical model simulated that the ${\gamma}-alumina$ could remove toluene at a loading rate of 0.4 mg/min only for a 4-hour period, which might be too short of a duration for real applications. Consequently, lifetime enhancement for ${\gamma}-alumina$ must be implemented, and ozone oxidation and regeneration would be feasible options.