• 한국가시화정보학회지
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• 제19권3호
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• pp.39-45
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• 2021

An experiment to visualize fine dust captured by FOG droplet is conducted. Coal dust with 23.56 MMD (Mean Median Diameter) and water with 17.02 MMD is used as fine dust and FOG droplet. Long distance microscope and high-speed camera are used to capture the images of micro-scale particles sprinkled by acrylic duct. After measuring and comparing the size of the coal dust and FOG droplet to MMD, process to seize the coal dust with FOG droplet is recorded in 2 conditions: Fixed and Floated coal dust in the floated FOG droplet flow. In both conditions, a coal dust particle is collided and captured by a FOG droplet particle. A FOG droplet particle attached at the surface of the coal dust particle does not break and remains spherical shape due to surface tension. Combined particles are rotated by momentum of the particle and fallen.

• 한국분무공학회지
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• 제27권4호
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• pp.173-180
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• 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.

• 한국분무공학회지
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• 제22권1호
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• pp.13-21
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• 2017

The fog screen is a device projecting the media to the aerosol flow field. As major parameters to generate dense and steady fog screen, shear stress, optical blockage ratio and SMD were obtained result through experiment. The micro droplet was generated by the piezo oscillation element, and the aerosol flow mixed with an air flow was sprayed into the vertical direction from the top of the fog screen through the 280 mm slot. For produce a dense, uniform fog screen, the shear effect, optical blockage ratio and SMD between aerosol and air curtain were measured. The minimum and maximum shear stress conditions were selected and it was confirmed that the optical transmission deviation of the aerosol flow field was small when the aerosol and air curtain flow rates were changed. When the aerosol and air curtain flow power were 18 V (1.51 m/s) and 24 V (2.55 m/s), respectively, under the condition of the minimum shear stress and laminar flow, the optical blockage ratios with the spray length were small, and it produced a most stable and high density uniform fog screen by injecting a constant of $10{\mu}m$ or less.

• Journal of Korean Society for Atmospheric Environment
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• 제24권E1호
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• pp.54-62
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• 2008

Microbeam PIXE, often called micro-PIXE, is one of powerful tools for analyzing a wide range of elements for various samples. Moreover, it has important applications of interest to the atmospheric science. In the present study, a qualitative elemental imagination for various atmospheric environmental species was attempted using micro-PIXE. Especially, in combination with a novel individual droplet collection method and the micro-PIXE analytical technique, the chemical specification of various individual atmospheric samples could be carried out. Here, we briefly introduce the results of an application of micro-PIXE to the study of atmospheric environment. The detailed spatial resolution of multiple elements for various samples like individual ambient particles, individual raindrops, individual fog droplets, and individual snow crystals could be successfully achieved by scanning 2.6 MeV $H^+$ micro beam ($1{\sim}2{\mu}m$) accelerated by 3 MeV single-end accelerator.

• 한국농공학회지
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• 제41권1호
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• pp.60-71
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• 1999

This study was performed to improve underirable warm greenhouse environment by fog cooling system in summer season. The resultsof droplet size analysis and cooling effects for fog cooling system are summarized as follows ; 1. At the pump pressure of 70kgf/$\textrm{cm}^2$ , the mean (SMD) drop size was 22.6${\mu}{\textrm}{m}$ and the maximum and minimum drop size was 45.68${\mu}{\textrm}{m}$ and 1.73${\mu}{\textrm}{m}$ , respectively, and almost all of the drop size was less than 40${\mu}{\textrm}{m}$. 2. The temperature of fog cooling greenhouse with 60% shading was dropped more than 2$^{\circ}C$ below the ambient temperature , while the greenhouse temperature without shading was 1$^{\circ}C$ higher than the ambient temperature. 3. It was found that fog spraying intervals were significantly influential on cooling effect. 4. When the greenhouse was ventilated sufficiently by natural vent system, green house temperature could be maintained by 2.5$^{\circ}C$ lower than the ambient temperature, while it was difficult to drop the greenhouse temperature below ambient temeperature without sufficient ventilation. 5. It was found that the temperature of experimental greenhouse could be maintained 3$^{\circ}C$ to 14$^{\circ}C$ lower that of control greenhouse though there were variations depending on experimental and weather conditions.

• 한국가시화정보학회지
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• 제22권1호
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• pp.34-39
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• 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 PM_2.5 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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.299-302
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• 2002

Characteristics of the twin fluid spray with ultrasonic forcing are examined in order to obtain the high efficiency of cold fog spray of the automatic pest control machine which has been widely used for the equipment cultivation recently. An electrostrictive vibrator of PZT BLT and a magnetostrictive vibrator of ${\pi}type$ with 28 kHz are applied as the ultrasonic transducer. All experiments are made and observed in 4 methods of spray ; a conventional spray method without ultrasonic forcing, an indirect vibration method with ultrasonic forcing, an improving duality method by ultrasonic forced within liquid, and a combined use method with both of the indirect vibration method and the improving quality method. In results, It was clarified that the ultrasonic effects the atomization of spray droplets and its efficiency is about $10{\%}$ and especially much more in the case of the combined use method.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2005년도 추계학술대회 논문집
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• pp.67-74
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• 2005

Microbeam PIXE, often called micro-PIXE, is a powerful tool tot analyzing a wide range of elements for various samples, as well as, it has important applications of interest to the atmospheric science. In this study, qualitative elemental imagination for various atmospheric environmental species was attempted using micro-PIXE. Here, we present the results of an application of micro-PIXE to the study of atmospheric environment. The detailed spatial resolution of multiple elements lot various samples like individual ambient particles, individual raindrops, individual fog droplets, and individual snow crystals could be successfully achieved by scanning 2.6 MeV H+ micro beam (1-2 ${\mu}m$) accelerated by 3 MV single-end accelerator.

• 식품기술
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• 제18권1호
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• pp.91-98
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• 2005

Aims: As a preliminary experiment on new sanitizer delivery tools, the efficacy of aerosolizedsanitizer on foodborne pathogens was investigated in larger model chamber system.Methods: Peroxyacetic acid and hydrogen peroxide were aerosolized in a model system againstartificially inoculated target microorganisms on laboratory media. Cultures of 4 different foodborne pathogens were inoculated and affixed onto 3 different heights (bottom, wall, and ceiling), and 3different orientations (face-down, vertical, and face-down) inside a commercial semi-trailer cabinet(14.6 x 2.6 x 2.8 m). Sanitizer was aerosolized into 2 m droplet size fog and treated for 1 h atambient temperature.Results: Populations of Bacillus cereus, Listeria innocua, Staphylococcus aureus, and Salmonellatyphimurium were reduced by an average of 3.09, 7.69, 6.93 and 8.18 log units per plate, respectively.Interestingly, L. innocua, Staph. aureus, and Salm. typhimurium showed statistically not different (P$\leq$ 0.05) reduction patterns relative to height and orientation that were never expected in a sprayingsystemConclusion and significance: Aerosolized sanitizers diffuse like gaseous sanitizers, so it has greatpotential for use in commercial applications.

• 생물환경조절학회지
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• 제20권4호
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• pp.394-398
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• 2011

토마토 시설재배에서 고온기에 온습도를 조절할 목적으로 사용되는 이류체 포그시스템을 이용한 온습도 조절이 가루이 방제에 미치는 영향을 알아보고자 연구를 수행하였다. 분무를 시작한 지 일주일 이내에 가루이의 개체수가 무처리구에 비해 약 87% 감소하였다. 온실의 일일평균기온은 이류체 포그시스템을 설치한 분무구에 서 $2^{\circ}C$ 정도 낮았다. 일일평균습도는 분무구에서 약 3~4% 높았다. 단, 온도나 습도의 차이로 분무구에서의 효과를 설명하기에는 어려움이 있었다. 저압분무 노즐에서 발생한 음향의 효과를 검증하기 위해 물을 제외하고 공기만 분사한 결과, 가루이의 생육에는 아무 영향이 없는 것으로 나타났다. 따라서 분무구의 효과는 노즐에서 뿜어져 나오는 미세수분입자가 가루이와 접촉하여 가루이의 생육을 억제한 것으로 판단된다.