• Particle and aerosol research
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• v.17 no.2
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• pp.29-36
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• 2021

In this study, the clean air delivery rate (CADR) of ceiling air circulator (CAA) was determined under indoor environmental simulation conditions. An air filter was used to provide air cleaning ability to the CAA. The CADR of filter adapted CAA was evaluated and compared with the value of commercial air purifier. The installation of mesh-shaped filter on the CAA showed particle reduction effect on the particles over 0.4 ㎛ in diameter, but the CADR was up to 0.25 m³/min. When the filter having 99.9% in collection efficiency was installed on the CAA, its CADR was 1.52 m³/min, while the CADR of commercial air purifier was 3.19 m³/min.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.4
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• pp.548-552
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• 2010

The air suction filter of the power plant decrease the dust and impurities of suction air that reduce the life and efficiency of the boiler. The suction efficiency of the air filter falls with the dust and impurities when the time of use comes to be long. Therefore, the various contaminant of the filter must remove periodically. This paper presents a developed quick exhaust valve to use in the thermo-electric power plant. to removing contaminants on the filter, the blowing is done shortly by air pressure. The Air flowed out to the out side from the inside of the filter. The performance test of the developed valve is done by making a test-bench according to JIS and KS standards. The efficiency is found higher than the existing related valve.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.149-154
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• 2005

Conventionally used flocculation tanks require large space and high energy requirement for mixing. Static flocculators using gravel bed filter operate at a lower flow rate ($5-10m^3/m^2{\cdot}h$). Further, the cleaning of this system is difficult. A novel high rate static flocculator/filter developed at UTS packed with buoyant media such as polystyrene, polypropylene has been found to operate at higher filtration rates (30-45 $5-10m^3/m^2{\cdot}h$). They can easily be cleaned with minimal energy. Detailed experiments conducted with an artificial kaolin clay solution show that buoyant media is an excellent static flocculator in producing uniform filterable microflocs (12-15 m) even when it is operated at a high rate of 30-40 m/h. Detailed filtration experiments were conducted in a wastewater treatment plant to treat the biologically treated effluent with a floating media of depth of 120 cm. This filter was able to remove majority of phosphorus and remaining solids. It reduced significantly the fecal coliforms and fecal streptoccoci, thus requiring less amount of chlorine for disinfection. The advantage of this system is the low energy and water requirement for cleaning of filter bed. The periodic backwash adopted 30 seconds air and water and 30 seconds water cleaning every 90 minutes filter operation. Thisis equivalent to 1-2% of filtered water production. Mechanical cleaning system on the other hand, requires very low energy requirement (<1% of filtered water production).

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.630-631
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.496-497
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• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.428-429
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• 2008

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.351.2-351
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• 2002

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1571-1578
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• 2015

The cleaning characteristics of pulse air jet type cleaning system which is widely applied in the industries were identified by utilizing the computational fluid dynamics (CFD) and the cleaning performance in modified shape of dedusting unit was compared in this study. The review on each shape of cleaning part showed that the case of installing the nozzle on the blow tube (Case-3) and the case of installing the double intaking tube to the venturi (Case-4 and Case-5) were more excellent than the structure (Case-1). Also, the optimal venturi shape was designed and examined its applicability to the site in a pilot scale plant. A combined system of a blow tube and a venturi proposed by this study turned out to be very effective for concentrating an cleaning air compared to existing systems, such as using only blow tube and combines the blow tube and venturi. In addition, as a result of installing and testing a venturi proposed by this study, the cleaning frequency and cleaning time were much improved compared to a case of using a commercial venturi that is under use at the industrial sites.

• Journal of Environmental Health Sciences
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• v.49 no.2
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• pp.78-88
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• 2023

Background: Exposure to volatile organic compounds (VOCs) can have acute and chronic health effects on human beings in general and in working environments. In particular, VOCs are often emitted in large quantities in industrial settings. In such circumstances, there is a need to improve the indoor air quality at workplaces. Objectives: The purposes of this study were to verify the effectiveness of air cleaning devices in workplaces and provide alternative solutions for improving working environments. Methods: Personal exposure and area level of VOCs for workers were evaluated in a car-part adhesive process before and after installing an air cleaning device with a TiO₂-coated filter. Passive samplers and direct reading instruments were used to collect and analyze the VOCs, and the removal efficiency and improvement of air quality were evaluated. We also calculated the exposure index (EI) to assess the risk level in the workplace. Results: The removal efficiency for VOCs through the installation of the air cleaning device was approximately 26.9~69.0% as determined by the concentration levels before and after installation. The measured substances did not exceed the exposure limits for the work environment and the EI was less than 1. However, carcinogenic substances such as benzene, formaldehyde, carbon tetrachloride, and trichloroethylene were detected. Conclusions: The application of an air cleaning device can be a solution for controlling the indoor air quality in a workplace, particularly in cases where ventilation systems cannot be installed due to process limitations.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.3
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• pp.183-190
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• 1994

Performance of domestic glass fabrics was tested in a Pulse- jet cleaned fabric filter under simulated coal combustion. Pulse Pressure were 2.5, 4.0kgf/$\textrm{cm}^2$ and pulse air nozzle diameter were 4.0, 6.0mm Pressure drop and penetration turned out to be low at small pulse air nozzle diameter and low pulse air pressure. Fractional penetration through the dust cake and fabric at face velocity of 1.7m/min was higher than that at face velocity of 1.0m/min. As a consequense, the performance of domestic glass fabrics was better with face velocity of less than 1.0m/min, pulse air pressure of 2.5 kgf/$\textrm{cm}^2$ and pusle air nozzle diameter of 4.0mm.