• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.5
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• pp.40-45
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• 2022

In recent years, indoor air pollution has become a crucial environmental problem. Hence, the purification of indoor air is an important issue. Typical physical filters show relatively high dust collection efficiency at a dust particle size of more than 5.0 ㎛ but extremely low efficiency at an ultrafine size of less than 2.5 ㎛. In this study, an electric field filter was proposed to capture ultrafine dust with a size of less than 5.0 ㎛. Simulation results showed that the electric field filter effectively removed ultrafine dust. In addition, sufficient dust collection efficiency was obtained even with a simple plate-shaped filter without bending the Chevron filter.

• International journal of advanced smart convergence
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• v.11 no.2
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• pp.30-37
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• 2022

Because fine dust (PM10) has a close effect on the environment, fine dust generated in the climate and living environment has a bad effect on the human body. In this study, the LSTM model was applied to predict and analyze the effect of fine dust on Gwangju Metropolitan City in Korea. This paper uses prediction values of input variables selected through correlation analysis to confirm fine dust prediction performance. In this paper, data from the Gwangju Metropolitan City area were collected to measure fine dust. The collection period is one year's worth of data was used from january to December of 2021, and the test data was conducted using three-month data from January to March of 2022. As a result of this study, in the as a result of predicting fine dust (PH10) and ultrafine dust (PH2.5) using the LSTM model, the RMSE was 4.61 and the test result value was as low as 4.37. This reason is judged to be the result of the contents of the one-year sample.

• Journal of the Korean Society of Visualization
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• v.22 no.1
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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.

• Particle and aerosol research
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• v.14 no.3
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• pp.73-80
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• 2018

Recently, there has been much research on the effect of ultrafine dust on human body with increasing interest in the ultrafine dust. In the Republic of Korea, there are many old thermal power plants, and the amount of ultrafine dust emitted from the thermal power plants is reported to be about 14% of the total amount of domestic fine dust. Therefore, the amount of fine dust from the flue gas desulfurization facility in the thermal power plant needs be reduced. In this study, we made an experimental setup to simulate a flue gas desulfurization facility and analyzed the physical characteristics of the particles passing through a mist eliminator. Experiments were carried out to investigate the collection efficiency of the mist eliminator by using the Arizona Test Dust in a dry environment, and then spraying limestone slurry into the flue gas desulfurization system equipped with the mist eliminator to examine the size and morphology of limestone particles upstream and downstream of the mist eliminator. Cut-off size of the mist eliminator was formed at about $6{\mu}m$. The result of this study is expected to be helpful for designing an electrostatic precipitator for removing particles passing through the mist eliminator.

• Clean Technology
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• v.27 no.1
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• pp.39-46
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• 2021

A road structure washing vehicle equipped with a 4 HP, 80 LPM ultrafine bubble generator was used to clean a tunnel wall and the surface of the surrounding structure, consisting of concrete and tiles, in a heavy traffic area around an apartment complex in the city. Ultrafine bubbles were generated by supplying air at 2 to 3 LPM and using a specially designed nozzle, whereas fine bubbles made by an impeller in a gas-liquid mixing self-priming pump were produced with an average diameter of 165.4 nm and 6.81 × 107 particles mL-1. Using a high pressure washer gun that can perform high-pressure cleaning at 150 bar and 30 LPM, ultrafine bubbles were used to wash dust adsorbed on the surface of the road structures. The experimental analysis was divided into before and after washing. The samples were analyzed by applying ISO 8502-3 to measure surface contamination of dust adsorbed on the surface. Using the transparent tape attached to the surface, the removal rate was calculated by measuring the weight of the dust, and the number of particles was calculated using the gravimetric method and the software, ImageJ. The results of the experiment showed that the number of dust particles adsorbed on the tile wall surface before and after washing were 3,063 ± 218 particles mL-1 and 20 ± 5 particles mL-1, respectively, with weights of 580 ± 82 mg and 13 ± 4 mg. Particles on the surface of the concrete structure before and after washing were 8,105 ± 1,738 particles mL-1 and 39 ± 6 particles mL-1, respectively, with weights of 1,448 ± 190 mg and 118 ± 32 mg.

• Journal of Platform Technology
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• v.8 no.4
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• pp.59-69
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• 2020

Recently, the seriousness of ultrafine dust and fine dust has emerged as a national disaster, but small and medium-sized cities in provincial areas lack fine dust monitoring stations compared to their area, making it difficult to manage fine dust. Although the computing resources for collecting and processing fine dust data are not large, it is necessary to utilize cloud and private and public data to share data. In this paper, we proposed a small edge computing system that can measure fine dust, ultrafine dust and temperature and humidity and process it to provide real-time control of fine dust and service to the public. Collecting fine dust data and using public and private data to service fine dust ratings is efficient to handle with edge computing using raspberry pie because the amount of data is not large and the processing load is not large. For the experiment, the experiment system was constructed using three sensors, raspberry pie and Thinkspeak, and the fine dust measurement was conducted in northern part of kyongbuk region. The results of the experiment confirmed the measured fine dust measurement results over time based on the GIS data of the private sector.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.123-124
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• 2021

Recently, the danger of fine dust has emerged worldwide. In general, fine dust refers to particulate matter less than 10㎛ and ultrafine dust less than 2.5㎛, and according to the announcement by HEI (Health Impact Research Institute) in 2015, the concentration of ultrafine dust in Korea is the second highest among OECD member countries. It was investigated. In this study, an experiment was conducted to analyze how the diatomaceous earth substitution rate affects the strength characteristics of the permeable block. As the replacement rate of diatomaceous earth increased, the strength decreased. The reason why the strength decreases with the use of diatomaceous earth is that the strength of the hardened body decreases as the structure of the hardened body becomes less dense as the amount of diatomaceous earth increases, and the reason that the strength decreases as the replacement rate of diatomaceous earth increases is the reason for the absorption performance of diatomaceous earth. Therefore, it is judged that a void was generated inside the hardened body while water was absorbed and then evaporated or discharged in the matrix, and accordingly, the strength decreased.

• The Journal of Bigdata
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• v.2 no.1
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• pp.17-26
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• 2017

The gradual desertification in Northeastern China brought about by the industrial development and global warming, has affected the Korean peninsula as evident by the ultrafine dust geographically and seasonally. People with severe respiratory problems, senior citizens and the infants are susceptible to the ill effects of fine dust which could prove fatal to them. Hence, we need to study the root cause of fine dust emergence and the correlation verification between fine dust and its side effects. This study firstly analyzed clean and contaminated areas classified by industrial elements. We utilized air, weather and industrial data in the area. Next, we detected a change of fine dust in terms of weather and climate. We analyzed correlation of air and weather by influence from domestic and neighboring country. The result indicated that China is the culprit of the emergence of fine dust predicament. Consequently, we can prove that fine dust ($PM_{10}$) and ultrafine dust ($PM_{2.5}$) could arise from geographical, seasonal, and pollutant elements. Therefore, we propose the optimum to make countermeasures about fine dust in terms of industry, topography, population and living residence.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.285-294
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• 2023

The importance of urban green space creation is increasingly recognized as the most realistic and efficient approach for fine dust mitigation in urban areas. Particularly considering the characteristics of domestic cities, the application of buffer green spaces along roads can maximize the efficiency of fine dust reduction without the need for separate green space creation. Accordingly, this study analyzed the fine dust mitigation effects based on the types of plantings in the central dividers and roadside trees in Jeonju City, Jeollabuk-do. To do this, we controlled various external variables of urban space and considered the planting arrangement types in the central dividers, carrying out the analysis using a CFD simulation. The simulation results confirmed that the central dividers with plantings demonstrated more effective ultrafine dust reduction than those without. Moreover, the arrangement of roadside trees showed a greater ultrafine dust reduction effect when adopting a multilayered structure compared to a single layer. Based on these findings, we concluded that installing both trees and shrubs simultaneously in the central dividers and along roads was effective for ultrafine dust mitigation. On this basis, we quantified the dust reduction effects of plants in urban street environments and proposed planting guidelines for roadside green spaces to improve air quality.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.461-468
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• 2019

Demand for improving dust removal efficiency in coal power plants and the dust removal requirement to the level of capturing fine particulate matter and ultrafine particles have been increasing. While bag filter and electrostatic precipitator (ESP) are typically used for dust removal in the processes operating at atmospheric pressure, metal filters or ceramic filters are employed for dust which is produced at high temperature/pressure system as in coal gasification. For dust removal at the high temperature/pressure conditions, two metal filters of five compressed/sintered layers were manufactured and applied to analyze the dust removal characteristics. Manufactured metal filters exhibited more than 99% dust removal efficiency on coal gasification fine particulates in mass basis. To evaluate the fine particulate removal efficiency of less than $2.5{\mu}m$, JIS standard fine sample was used and confirmed the removal efficiencies of 97% and 70~82% on the fine particulates of $1{\sim}2.5{\mu}m$ size range. For the size range of less than $1{\mu}m$, dust removal efficiency of manufactured metal filters significantly degraded with smaller particle size. Improving methods are proposed to overcome the limitations in applying to fine dust of less than $1{\mu}m$.