• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.6
• /
• pp.959-964
• /
• 2009

This paper dealt with the disinfection performance by Ultra-Violet Light Emitting Diode (UV LED) for a phytoplankton as a basic study for the development of a low-energy consumption ballast water treatment system. UV LEDs having peak wavelength of 255nm, 265nm and 280nm were used in the experiment. UV LED modules with driving circuit were fabricated, and optical and electrical characteristics of them were analyzed. The disinfection performance for phytoplankton depending on the UV wavelength was evaluated by comparing the number of phytoplankton before and after the UV treatments. The experimental result showed that the highest disinfection wavelength for the phytoplankton was 265nm.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.4
• /
• pp.616-622
• /
• 2015

Current ballast water treatment technologies are applying chemical or electrical treatment technology which are not free from secondary environmental pollution. The purpose of this study is to treat the ballast water by shear stress without an additional environmental pollution and to find out the optimal treatment apparatus. We tried to treat ballast water by applying shear stress with two different type of combination of inner and outer cylinder, such as non-pattern type and groove type. In the case of non-pattern type of inner and outer cylinder, sterilization effect was comparatively low because of a slip between inner and outer cylinder. But in the case of groove type of inner and outer cylinder, sterilization effect was superior to the non-pattern type. With a same revolutional speed of 8000rpm, an extinction effect was acquired in the gap of 1 mm of inner and outer cylinder at non-pattern type, but 3mm of that of groove type.

• Journal of Advanced Marine Engineering and Technology
• /
• v.34 no.6
• /
• pp.880-886
• /
• 2010

In this paper, we studied the application of low pressure ultra-violet (UV) lamps for the development of an energy saving ship's ballast water treat (BWT) device. We proposed the optimal arrangement of UV lamps by analyzing the energy radiated from medium- and low-pressure UV lamps. Based on the experimental results, we manufactured a disinfection chamber which is composed of low-pressure UV lamps. The rated power and the treatment capacity of the chamber are 216 [W] and 10 [$m^3$/h], respectively. This can replace a disinfection chamber treated by two 2 [kW] medium pressure lamps. The disinfection performance, however the power consumption is about one-eighteen compare to the medium pressure UV lamp, is over 94 [%] for bacteria, 93 [%] for zooplankton, and 94 [%] for phytoplankton. Therefore, it would be possible to develop an energy saving BWT device in a low capacity below 100 [$m^3$/h].

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.25 no.6
• /
• pp.511-519
• /
• 1992

A microcomputer based control system was constructed to save energy consumption in the thermal sterilizing process. The functional accuracy of system was evaluated through the analysis of the thermal diffusivities of the model solid food, Alaska pollack surimi. The heat penetration curves obtained through the experiments were typical for solid foods. The practical thermal diffusivity calculated from heat penetration curve was a constant value at steady sterilizing temperature, and this was independent of the holding time. At different temperatures, the thermal diffusivity values did not show remarkable differences when compared with those predicted by some experimental equations cited from the literatures. The maximal difference was within the range of $\pm10.0\%$.

• Journal of the Society of Disaster Information
• /
• v.19 no.2
• /
• pp.344-351
• /
• 2023

Purpose: This study aimed to evaluate the effectiveness of a dielectric barrier discharge (DBD) plasma module for sterilizing airborne bacteria in indoor spaces and measure the concentration of ozone generated during plasma discharge. Method: The DBD plasma module was installed in a 76m³ space, and air samples were collected under various discharge times to compare the reduction of airborne bacteria. Result: The results showed a significant decrease in airborne bacteria, ranging from 92.057% to 99.999%, with an average ozone concentration of 0.04 ppm, below the reference value. Conclusion: The study suggests that plasma discharge can be used as a means of preventing the spread of airborne bacteria and viruses, while ensuring safety for human exposure.

• Proceedings of the SAREK Conference
• /
• 2004.06a
• /
• pp.57-57
• /
• 2004

• Applied Chemistry for Engineering
• /
• v.16 no.4
• /
• pp.570-575
• /
• 2005

In this study, we have manufactured electrodeless ultraviolet lamp which has a long life and a high degree of efficiency than the existing electrode UV lamp used in sewage effluent sterilization disinfection. First, we investigated change of UV intensity and temperature of lamp by activation materials. The best results for the dose response experiments were 250 minutes stabilizing to UV intensity of $300{\mu}W/cm^2$ and surface temperature $200{\sim}250^{\circ}C$ in Hg/Ind's weight ratio 95/5. When electrodeless UV lamp emits light for prolonged hours, surface temperature of lamp increases. therefore, temperature change is studied using a duplex lamp for cooling in actual sewerage process. Also, manufactured electrodeless UV lamp showed sterilization efficiency of more than 99.9% as result that experiment manufactured electrodeless UV lamp by E-coli. for sterilization disinfection of sewage effluent.

• Applied Chemistry for Engineering
• /
• v.22 no.5
• /
• pp.453-460
• /
• 2011

Recently, there is growing interests in the application of supercritical fluids for food and medical fields since supercritical fluids ($CO_2$ and $N_2O$) have known to be safe and effective as a non-thermal sterilization technique. Although supercritical fluids have been investigated for various kinds of products, they have not yet been used in common currency due to their lack of knowledge related to the antimicrobial activity or detailed mechanisms. In this review paper, we summarized the characteristics, antimicrobial activity and mechanisms, important factors, and applicability of supercritical fluids to help the investigation and commercialization of supercritical fluids sterilization technique.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.14 no.3
• /
• pp.51-59
• /
• 2006

The air purity-sterilizer was developed and the CFD and experimental studies were carried out in order to investigate the performance of a air purity-sterilizer. Overhaul and exchange efficiency were increased by the modularization of the air purity-sterilizer. The good performance was validated by the hot-wire measurements and flow simulations in the room. Mean velocities at the exit of the air purity-sterilizer were 0.91, 1.62, 1.99, and 6.14 m/sec according to the fan mode. And the flow visualization of pured air was shown by using CFD flow simulation in the room of 24, 50 pyeong. The results show that the air purity-sterilizer has a high performance enough to produce air purity-sterilizer on a commercial scale.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.16 no.3
• /
• pp.250-257
• /
• 2004

Recently, the use of UVC lamps inside building air-conditioning system has been increasing in both medical and nonmedical buildings for the control of environmental microorganisms. In the present study, irradiance performance test of UVC lamp was carried out and surface sterilization effect of UV ray was investigated by using UV ray irradiation experimental chamber and pilot system. Experimental results show that the effective irradiance of UVC lamp is strongly dependent on air velocity and temperature with exception of relative huminity in air-conditioning system. An individual microbiological kill effectiveness experiment also shows that the fractional kill of two microbiological samples such as E. Coli and Legionella is roughly the same as the estimated fractional kill in the case of chamber test and pilot system test.