• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.4
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• pp.305-311
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• 2003

DOP aerosol particles with geometric mean diameter of 0.5-3.0 ${\mu}{\textrm}{m}$, geometric standard deviation of 1.1-1.3 and total number concentration of 1,500-8,000 Particles/㎤ were used to determine collection efficiencies of a packed wet scrubber with respect to particle size. The tested operating variables included air velocity and water injection rate. It was shown from the experimental results that the collection efficiencies increased with increasing water injection rate and decreasing air velocity. Meanwhile, as for the particle size variation, all of the collection efficiency curves increased rapidly between 0.57-1.41${\mu}{\textrm}{m}$ for the range of water injection rate above 30 L/min. It was also seen that the collection efficiency of a packed wet scrubber is mainly governed by the mechanism of inertial impaction.

• Journal of Korean Society on Water Environment
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• v.18 no.3
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• pp.237-243
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• 2002

The effect of a salinity on the performance of a biological nutrient removal system was investigated using a model SBR(Sequencing Bach Reactor) system. The system was operated at a 12hr, 18hr, 24hr, and 36hr HRT with a salinity level of 20,000mg/L and compared with a system similarly operated with fresh water. The influent salinity level of 8,000 mg/L does not have a significant effect on BOD removal efficiency, there is a noticeable decrease in BOD removal rate from 10,000 mg Cl-/L. The Nitrogen could be removed from the saline wastewater with the same efficiency as for the fresh water because of low C/N ratio in anoxic period. The excess biological phosphorous removal is highly affected by the increase in the influent salinity. The efficiency is decreased from 96.6% to 43.4% when the influent salinity is increased from 0 to 20,000mg/L.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.05a
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• pp.101-112
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• 1995

In order to improve the recovery efficiency of heavy water vapour from the atmosphere inside a reactor building, and to recover and upgrade the heavy water which escape, special treatments, such as reducing the ingress of light water vapour, are studied in the design of the CANDU reactor systems. This is considered in controlled method of the humidity over drawing fresh air through a desiccant dehumidifier which dries the air by absorption. Comparing with the moisture loads between summer and winter operations, the moisture removal rates are calculated. Those are proportional to the difference between the controlled space and the surrounding environment Installation of a new dehumidifier will be able to reduce the moisture loads from the cooling systems, improving overall system efficiency and saving operating costs.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.5
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• pp.589-601
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• 1997

A computer simulation program of a high efficiency condensing heat exchanger is developed. The flue gas flows outside bare tube bundles both in strong cross flow and in weak counter flow and the cooling water inside the tubes. Condensing heat exchangers achieve high efficiency by reducing flue-gas temperatures to a level at which most of the water vapor in the flue gas is condensed and the latent heat associated with phase change of the water is recovered. The computer model has been verified by comparison with measured data. To verify the model, heat transfer coefficient was adjusted, along with the mass transfer diffusion coefficient and pressure drop coefficient, to achieve agreement between predicted and measured data. The efficiencies of heat exchanger increase 2.3 ~ 8.1% by condensations of 6.3 ~ 62.6% of the water vapor in the flue gas.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.4
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• pp.141-148
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• 2009

Afterfogging of the regenerative gas turbine system has an advantage over inlet fogging in that the high outlet temperature of air compressor makes the injection of more water and the recuperation of more exhaust heat possible. This study investigates the effects of turbine inlet temperature (TIT) on the performance of regenerative gas turbine system with afterfogging through a thermodynamic analysis model. For the standard ambient conditions and the water injection ratios up to 5%, the variation of system performance including the thermal efficiency is numerically analyzed with respect to the variations of TIT and pressure ratio. It is also analyzed how the maximum thermal efficiency, net specific work, and pressure ratio itself change with TIT at the peak points of thermal efficiency curve. All of these are found to increase almost linearly with the increases of both TIT and water injection ratio.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.6
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• pp.53-59
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• 2012

This this study was conducted with the aim of doing experiment on the effect of water purification by using an artificially built plant island, which is one of the eco-techniques, and aquatic plants as a plan for the reuse of water for obtaining water resources, thereby analyzing the removed quantity, and applying the experimental results to the reuse of water. As a result of doing experiments, this study obtained a good measured value of BOD (biochemical oxygen demand) 4.7mg/L, and COD (chemical oxygen demand) 7.2mg/L below the heavy water standard of BOD 10mg/L and COD 20mg/L, respectively. The chromaticity showed 89.2% removal efficiency, but final treated wastewater was found to show chromaticity 58 degrees exceeding chromaticity 20 degrees which are the water quality standard of the reuse of water. The results revealed that T-N produced 27% removal efficiency on an average while T-P produced 38% removal efficiency on an average, showing that the removal effect of N & P wasn't big. According to the currently enforced "Water Quality Standard of Heavy Water by Use", the use of water for sprinkling and landscaping was found to be available. Accordingly, this study suggested a nature-friendly, economically-efficient, and eco-technological water treatment technique which will make it possible to overcome the limit of the existing physio-chemical water treatment technology, reduce the costs for maintenance and facilities, and also reduce the limit of space restraint for installation of facilities.

• Proceedings of the Korea Water Resources Association Conference
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• 2002.05a
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• pp.449-454
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• 2002

• 수도
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• v.26 no.2 s.90
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• pp.55-63
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• 2000

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.735-741
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• 2009

This study intends to evaluate the efficiency of non-point source reduction technique by using the porous lightweight and recycled aggregate which microorganism is seeded. In case of infiltration velocity 30~70 mm/hr in high concentration of influent, it is indicated that SS was 40~94%, COD 44~91%, BOD 4~91%, TN 1.2~66%, TP 7~70% of removal efficiency. Removal efficiency is good in infiltration velocity 30 > 50 > 70㎜/hr order. Therefore, the non-point source treatment facility filled with lightweight and recycled aggregate using microbial seeding shows higher removal efficiency than a conventional sand and gravel. We confirm that the function and efficiency are improved significantly and applied to treat non-point sources.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.577-580
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• 2007

The influence of flow rate has been investigated on the treatment efficiency of continuous cycling electrolytic process employing artificial and actual photographic wastewater which containing silver ion. For artificial wastewater, the treatment efficiency of process was found to rise ca. three times when the flow rate of wastewater was increased from 3 mL/min to 15 mL/min. The process efficiency was doubled under the same condition regarding actual wastewater. The effect of flow rate on the treatment efficiency was observed to be altered according to the metal ionic form and solution composition. The coefficient of mass transfer was estimated using model equation, which verified that the raised treatment efficiency at higher flow rate was due to the increased mobility of ionic species.