• Title/Summary/Keyword: Dry Fog

Search Result 29, Processing Time 0.028 seconds

Experimental study on the generation of ultrafine-sized dry fog and removal of particulate matter (초미세 크기의 마른 안개 생성과 이를 이용한 미세먼지 제거 연구)

  • Kiwoong Kim
    • Journal of the Korean Society of Visualization
    • /
    • v.22 no.1
    • /
    • pp.34-39
    • /
    • 2024
  • With the fine particulate matter (PM) poses a serious threat to public health and the environment. The ultrafine PM in particular can cause serious problems. This study investigates the effectiveness of a submicron dry fog system in removing fine PM. Two methods are used to create fine dust particles: burning incense and utilizing an aerosol generator. Results indicate that the dry fog system effectively removes fine dust particles, with a removal efficiency of up to 81.9% for PM10 and 61.9% for PM2.5 after 30 minutes of operation. The dry fog, characterized by a mean size of approximately 1.5 ㎛, exhibits superior performance in comparison to traditional water spraying methods, attributed to reduced water consumption and increased contact probability between water droplets and dust particles. Furthermore, experiments with uniform-sized particles which sizes are 1 ㎛ and 2 ㎛ demonstrate the system's capability in removing ultrafine PM. The proposed submicron dry fog system shows promise for mitigating fine dust pollution in various industrial settings, offering advantages such as energy consumption and enhanced safety for workers and equipment.

Electrical Conduction Properties of Surface in Materials for Outdoor Insulator (옥외 애자용 재료의 표면 전기전도 특성)

  • 박영국;이운석;정수현;장동욱;임기조
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.11 no.10
    • /
    • pp.758-762
    • /
    • 1998
  • Electrical conduction property of insulator surface is most important factor to assess the insulation performances of outdoor insulating materials. In this paper, contamination performance of the materials to be used for outdoor insulator such as porcelain, EPDM, silicone rubber was discussed by measuring properties of average leakage current and scintillation discharge pulses under salt fog conditions. The fog was applied by nozzle in chamber and fogging fluids were deionized distilled water, 0.5wt% NaCI solution and 2wt% NaCl solution. The average leakage current showed linearly with applied voltage at dry and clean surface condition. The magnitude of leakage current was almost same at different kinds of samples. In case of deionized distilled water fog, the characteristics of leakage current and applied voltage were much different to those in case of dry and clean condition with 2wt% salt fog. In case of slat fog pollution condition, the leakage current was increased above critical voltage. the scintillation discharges were also activated at the level. The leakage current and scintillation discharges were increased with increasing pollution degree. The resistance to pollution properties of silicone rubber appeared excellent among them.

  • PDF

Properties of PD Pulses accompanying with propagation of Bush-type tree in LDPE (LDPE에서 부시형 전기트리의 성장에 수반되는 부분방전 펄스의 특성)

  • 박영국;강성화;정수현;박철현;임기조
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1998.06a
    • /
    • pp.293-296
    • /
    • 1998
  • Surface electrical conduction in insulator is most important factor to assess the insulation performances of outdoor insulating materials. In this paper, contamination performance of the widely used materials for outdoor insulator - porcelain, EPDM, Silicone rubber - were discussed by measuring properties of average leakage current and scintillation discharge pulses under artificial contamination conditions. The artificial contaminations used were deionized distilled water fog, 0.5wt% NaCl salt fog of light pollution and 2wt% NaCl salt fog of medium pollution. The average leakage current was appeared linearly with applied voltage at dry and clean surface condition. The magnitude of leakage current was almost same at different kinds of samples. In case of deionized distilled water fog, the characteristics of leakage current and applied voltage was most different to that in case of dry and clean condition. In case of salt fog pollution condition, The leakage current was increased above critical voltage. The scintillation discharges were also activated at the level. the leakage current and scintillation discharges were increased with increasing pollution degree. The resistance to pollution properties of silicone rubber appeared excellent among them.

  • PDF

Properties of Surface Electrical Conduction in Materials for Outdoor Insulator (옥외 애자용 재료의 표면 전기전도특성)

  • 박영국;강성화;정수현;이운석;임기조
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1998.06a
    • /
    • pp.207-210
    • /
    • 1998
  • Surface electrical conduction in insulator is most important factor to assess the insulation performances of outdoor insulating materials. In this paper, contamination performance of the widely used materials for outdoor insulator - porcelain, EPDM, Silicone rubber - were discussed by measuring properties of average leakage current and scintillation discharge pulses under artificial contamination conditions. The artificial contaminations used were deionized distilled water fog, 0.5wt% NaCl salt fog of light pollution and 2wt% NaCl salt fog of medium pollution. The average leakage current was appeared linearly with applied voltage at dry and clean surface condition. The magnitude of leakage current was almost same at different kinds of samples. In case of deionized distilled water fog, the characteristics of leakage current and applied voltage was most different to that in case of dry and clean condition. In case of salt fog pollution condition. The leakage current was increased above critical voltage. The scintillation discharges were also activated at the level the leakage current and scintillation discharges were increased with increasing pollution degree. The resistance to pollution properties of silicone rubber appeared excellent among them.

  • PDF

A Study on Reduction Effect of White Smoke Fog in Urban Detention Basin using a Fog Removal System (안개제거장치를 이용한 도심 저류지 시설에서의 안개 저감 효과 연구)

  • Lee, Kyu Hong;Lee, Sang Woo;Choi, Jun Sung;Lee, Sung Kyun;Park, Jihwan;Park, Seunghee
    • Journal of Korean Society of Disaster and Security
    • /
    • v.11 no.2
    • /
    • pp.69-74
    • /
    • 2018
  • Fog to which environmental impacts are sensitive has a danger to the safety of citizens due to the difficulty in predicting the specific area/time zone. Therefore, we propose a white smoke fog reduction technique using a fog removal device that can remove fog particles directly through dry air and anionic condensation nucleus instead of conventional passive countermeasures. In this study, to verify the effect of reducing fog and the effect of temperature on the white smoke fog which is frequently occurred in the detention basin. As a result, the visible distance of 100m or more was secured within 30 seconds, and it was confirmed that the fog reduction effect is more effective. Also, the lower the temperature, the larger the amount of white smoke fog was. However, the effect of reducing the white smoke fog by temperature was insignificant. Through this experiment, it was possible to verify the reduction effect of the white smoke fog generated in the detention basin through fog removal device.

Effect of Dry Fog Injection on Waste Decomposition in an Aerobic Landfill (호기성매립지에서 드라이포그 주입에 의한 폐기물분해 촉진에 관한 연구)

  • Park, Jin-Kyu;Lee, Byung-Sun;Yoon, Seok-Pyo;Lee, Nam-Hoon
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.26 no.2
    • /
    • pp.43-51
    • /
    • 2018
  • The objective of this research was to assess the effect of moisture content and water injection method into the landfill on waste decomposition in an aerobic landfill. Firstly, respirometric experiments were performed in order to assess the effect of initial moisture content (20%, 30%, 40% and 50% respectively) on landfilled waste decomposition. The cumulative oxygen uptake and oxygen uptake rate were highly increased with the increase of initial moisture content. Secondly, lysimeter experiments showed that in comparison with the vertical injection method, dry fog system enhanced decomposition of organic wastes. Also, dry fog system provided uniform moisture distribution more than the vertical injection method within landfill.

Experimental Study on the Spray Characteristics of Low Pressure Fog Nozzles in Cooling Fog System (쿨링 포그 시스템의 저압 안개 노즐 분무특성에 대한 실험적 연구)

  • Ji Yeop, Kim;Cheol, Jeong;Won Jun, Kang;Jeong Ung, Kim;Jung Goo, Hong
    • Journal of ILASS-Korea
    • /
    • v.27 no.4
    • /
    • pp.173-180
    • /
    • 2022
  • Cooling fog is being used in various parts of society such as fine dust reduction, cleanliness, and temperature drop. Cooling fog has the advantage of low flow rate and ease of use compared to other spray systems. In the case of cooling fog, it was confirmed that the injection angle increased as the pressure increased and the nozzle diameter increased. In this study, the minimum injection angle was 33.61 degrees and the maximum injection angle was 107.38 degrees. It was confirmed that the larger the nozzle diameter and the smaller the pressure, the larger the droplet size. In addition, it was confirmed that the Sauter Mean Diameter (SMD) increased along the X and Y axis directions. It was confirmed that the size of the droplet decreases as it approaches the nozzle tip due to the characteristics of the nozzle design factor.

On the Steam Fog in the Gumi Reservoir of Nakdong River (낙동강 구미 보의 증기 안개에 관한 연구)

  • Kim, Hae-Dong;Cho, Chang-Bum;Seo, Kwang-Su
    • Journal of Environmental Science International
    • /
    • v.25 no.1
    • /
    • pp.163-171
    • /
    • 2016
  • We analyzed the characteristics of fog formation in the Gumi Reservoir of Nakdong river with the field observation data for recent 2 years (1 April 2013~31 March 2015) collected by the national institute of meteorological research, KMA. In early morning, we frequently observe the steam rising from the water surface. The fog occurs from adding water vapor into the air. We call the fog as steam fog. Steam fogs occur when cold, dry air mixes with warm, moist air above a water surface. The steam fog appears mainly in autumn under the following conditions; (1) sensible heat is positive values ($10{\sim}20W/m^2$), (2) latent heat is more positive values ($25{\sim}35W/m^2$) than sensible heat, (3) cloudless nights with light winds (about 1.5 m/s), (4) under condition(3), mountainous winds easily blows into the reservoir.

Growth and Rooting Rate of 'Maehyang' Strawberry as Affected by Irrigation Method on Cutting Propagation in Summer Season (하절기 '매향' 딸기의 삽목 번식 시 관수방법에 따른 생육 및 발근율)

  • Kim, Hyeon Min;Kim, Hye Min;Jeong, Hyeon Woo;Lee, Hye Ri;Jeong, Byoung Ryong;Kang, Nam Jun;Hwang, Seung Jae
    • Journal of Bio-Environment Control
    • /
    • v.27 no.2
    • /
    • pp.103-110
    • /
    • 2018
  • This study was conducted to investigate the optimum irrigation method for propagation of cutting strawberry ($Fragaria{\times}ananassa$ Duch. cv. Maehyang) plantlet in summer season. The cutting strawberry plantlets were planted in 24-cell tray ($60{\times}34{\times}10cm$) filled with commercial mixed medium (Tosilee) and placed in semi closed-type small plastic tunnel. Each semi closed-type small plastic tunnel was treated as follows; control (non-treatment), over head irrigation (twice a day), capillary mats irrigation (twice a day), or fog irrigation (30 minutes turn on and 10 minutes off from 8:00 to 18:00). The strawberry plantlets were rooted during 8 days in the semi closed-type small plastic tunnel, and then plastic film was removed. Growth parameters, such as plant height, root length, number of primary roots, petiole length, leaf length, leaf width, crown diameter, SPAD, leaf area, fresh and dry weights of the shoot and root, were measured at 61 days after cutting. Relative humidity in tunnel was high in the order by fog irrigation, over head irrigation, capillary mats, and the control as 72.5, 56.3, 45.8, and 29% on average, respectively. However, the air temperature was similar in all treatments. On the 4 and 8 days, the rooting rate of strawberry plantlet was significantly higher in the over head irrigation and fog irrigation treatments. Plant height, petiole length, crown diameter, and leaf area were highest in the over head irrigation and fog irrigation treatments. In addition, fresh and dry weights of shoot were greater in over head irrigation and fog irrigation treatments than the others. Dry weight of root was differed significantly heaviest in the fog irrigation treatment. However, root length, no. of primary roots, SPAD value, and fresh weight of root were not significantly different in all treatments. These results indicated that growth and rooting for propagation of cutting strawberry plantlet 'Maehyang' were best achievement in the over head irrigation and fog irrigation treatments.

Analysis on Waveform of Leakage Current of Contaminated EPDM Insulators by Salt Fog (Salt fog에 의한 오손된 EPDM애자의 누설전류 파형 분석)

  • Park, Jae-Jun;Song, Young-Chul;Kim, Jeong-Boo;Lee, You-Min;Lee, Hyun-Dong;Jung, Young-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.11a
    • /
    • pp.36-41
    • /
    • 2003
  • This paper presents the results of power spectra using the fundamental and low frequency harmonic components of leakage current waveform to study aging on contaminated EPDM insulator(was serviced during 1997-2001, region Pohang, korea) under salt fog conditions. Experiments have been conducted in the chamber salt fog and at the 16KVrms. The salt contents adjusted as 0g,25g,50g and 75g per liter of deionized water. The onset of dry-band arcing on polymer insulators could be determined by signal processing the low frequency harmonics components. A correlation has been found between the fundamental and low harmonic components of power spectra on leakage current. Where aging could be associated with an increase in the level of both the fundamental and low frequency harmonics components of leakage current. Surface aging for contaminated EPDM insulators occurred when the fundamental component of leakage current was greater then some level On the other hand, when the polymer insulator approached failure, the fundamental component of leakage current reached relatively high values and low frequency harmonics components of the leakage current trended to decrease. The results suggest that both the fundamental and low frequency harmonics of leakage current can be used as a tool to determine both the beginning of aging and before flashover, end of life EPBM insulator in salt fog.

  • PDF