• 환경위생공학
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• 제12권3호
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• pp.73-79
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• 1997

This research was intended as an investigation of applying Reduced Pressure Evaporation as efficient treatment method for landfill leachate. According to the variance of time, temperature, pressure and pH in experiments, the properties of leachate treatment are follows. The removal efficiencies of COD, NH$_{3}$-N, TOC, Conductivity and SS on the basis of reaction time was 96.4%-97.5%, -1.4%-53.7%, 81.7%-89.0%, 92.0%-95.3% and 99.86%-99.97%, respectively. When the pH of Influent was 7.5, the pH of effluent was increased to 10-11 with time elapse. It is concluded that the orgin of pH increase may be ammonia. When the properties of concentrate were investigated at the concentration ratio 90%(V/V), concentration difficiency represented in the ratio of experimental value/calculated value had following orders ; COD>TOC>NH$_{3}$-N>Conductivity>SS. Concentrate had good precipitation because of additive thermal treatment in the process. When evaporation experiments with pH adjustment of 4.0, 6.0, 7.5, 9.0 and 10.0 were performed ; Acidic evaporation experiments(pH 4.0, 6.0) showed low removal efficiency(81.6, 87.6%) of COD and high removal efficiency (97.5%. 84.6%) of NH$_{3}$-N at initial evaporation. Basic evaporation(pH 9.0, 10.0) showed high removal efficiency (97.2%, 98.9%) of COD and very low removal efficiency (-7.4%, -27.2%) of NH$_{3}$-N at initial evaporation.

• 반도체디스플레이기술학회지
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• 제7권1호
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• pp.35-40
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• 2008

In OLED vacuum evaporation process, the essential requirements include good uniformity of the film thickness over a glass substrate. And, it is commercially significant to improve the consuming efficiency of material of the evaporant which is deposited on the substrate because of high price of organic materials. In this paper, to achieve the better thickness uniformity and the better organic material consuming rate, a process optimization algorithm was developed by understanding vacuum evaporation process parameters that affect the material consuming efficiency and the uniformity of film thickness. Based on the method developed in this study, the vacuum evaporation process of OLED was successfully controlled. The developed method allowed the manufacture of high quality OLED displays with cheaper fabrication cost.

• 한국수자원학회논문집
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• 제49권2호
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• pp.165-175
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• 2016

본 연구에서는 일사량에 기초한 증발량 산정방법의 적용성을 검토하기 위해 기존에 연구자들에 의해서 제안된 식들을 3가지 형태의 model group (Model groups A, B, and C)으로 분류하고, 이를 우리나라 6개 지역(서울, 대전, 전주, 부산, 목포, 제주)에 적용하였다. 증발접시 증발량 자료를 이용하여 이들 model group들의 매개변수를 추정하고, 검증하였다. 또한 Penman (1948) 조합식을 적용하여 이들 model group들과 비교하였다. 연구결과에 의하면 모든 지역에서 Nash-Sutcliffe (N-S) 효율지수가 0.663 이상을 보여서 만족스러운 증발량 산정결과를 보였다. 모형 검증과정에서 산정된 N-S 효율지수는 모든 연구지역에서 0.526이상을 보여서 역시 만족스러운 결과를 보였으나, 부산지역에서 적용된 Model groups B와 C를 제외하고는 모두 Penman (1948) 조합식보다 작은 N-S 효율지수를 보였다. 따라서 주요 기상자료 일부(풍속, 상대습도)가 부족하거나 측정되지 않는 경우에 증발량 산정을 위해서 Penman (1948) 조합식을 대체하여 일사량자료에 기초한 증발량 산정 방법이 적용될 수 있을 것으로 사료된다.

• 한국입자에어로졸학회지
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• 제12권4호
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• pp.135-143
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• 2016

Removal of water contents in a gas is needed in industrial field of gas processing related on energy production/conversion, and environmental treatment. Inertial separators are economic devices for separating droplets from the gas stream. For accurate understanding of removal process in a curved vane mist eliminator, a numerical model including turbulent dispersion, evaporation and condensation of water vapor at surface of droplets is required. A two-stage curved vane mist eliminator has been modeled, and fluid flow of mixture of air and water vapor and droplet trajectories were solved simultaneously with taking into account two-way coupling. Removal efficiency of droplets with various inlet condition of relative humidities (RH, 40%, 90%, and 100%) were compared. As RH increased, the effect of evaporation decreased and inertial separation efficiencies of droplets obtained increased especially for droplets of diameter below 10 micrometers.

• 설비공학논문집
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• 제28권11호
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• pp.434-443
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• 2016

The evaporation of water from an aqueous solution is widely used in the food, desalination, pulp, and chemical industries. Usually, a large amount of energy is consumed in the evaporation process to boil off water due to atmospheric pressure. As a way of improving the energy efficiency of the evaporation process, the combination of multiple effect evaporation and thermal vapor recompression has been proposed and has become a successful technique. In this study, 4 multiple-effect falling film type evaporators for sugar solution are designed and the energy efficiency of the system is analyzed in response to the selection of the steam ejector position. Energy efficiency is increased and vapor is more compressed in the steam ejector as the Thermal Vapor Recompression (TVR) is arranged in the rear part of the evaporator system. A simplified 0-dimensional evaporator model is developed using non-linear equations derived from mass balances, energy balances, and heat transfer equations. Steam economy is calculated to compare the evaporation performance of the 4 proposed evaporators. The entrainment ratio, compression ratio, and expansion ratio are computed to check the ejector performance.

• Journal of Advanced Marine Engineering and Technology
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• 제36권5호
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• pp.580-585
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• 2012

R744용 해양온도차 발전 시스템의 작동변수에 대한 기초 설계자료를 제공하고자 증발열량, 응축열량, 전체일량, 효율에 대한 사이클 성능을 분석하였다. 본 연구에서 고려된 작동변수는 R744 해양온도차 발전 사이클의 과열도, 과냉각도, 응축온도, 증발온도 등이다. 주요 결과를 요약하면 다음과 같다. R744의 증발열량은 과열도와 과냉각도가 증가할수록 증가하는 반면, 응축온도가 증가할수록 감소한다. 전체일량은 R744의 과열도와 과냉각도와 함께 증가하나 증발온도는 증가할수록 감소한다. 그리고 효율은 과열도와 과냉각도가 증가할수록 증가하는 반면, 응축온도는 감소한다. 그러므로 R744용 해양온도차 발전 시스템의 증발열량, 응축열량, 전체일량, 효율은 과열도, 과냉각도, 응축온도, 증발온도, 펌프와 터빈 효율에 영향을 받는 것을 알 수 있었다. 따라서 R744용 해양온도차 발전 시스템의 설계시에는 이러한 영향을 면밀하게 파악하여야 한다.

• 한국재료학회지
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• 제21권1호
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• pp.56-66
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• 2011

Multi-source evaporation is one of the methods to improve the thickness uniformity of thin films deposited by evaporation. In this study, a simulator for the relative thickness profile of a thin film deposited by a multi-source evaporation system was developed. Using this simulator, the relative thickness profiles of the evaporated thin films were simulated under various conditions, such as the number and arrangements of sources and source-to-substrate distance. The optimum conditions, in which the thickness uniformity is minimized, and the corresponding efficiency, were obtained. The substrate was a 5th generation substrate (dimensions of 1300 mm ${\times}$ 1100 mm). The number of sources and source-to-substrate distance were varied from 1 to 6 and 0 to the length of the major axis of the substrate (1300 mm), respectively. When the source plane, the area on which sources can be located, is limited to the substrate dimension, the minimum thickness uniformity, obtained when the number of sources is 6, was 3.3%; the corresponding efficiency was 16.6%. When the dimension of the source plane is enlarged two times, the thickness uniformity is remarkably improved while the efficiency is decreased. The minimum thickness uniformity, obtained when the number of sources is 6, was 0.5%; the corresponding efficiency was decreased to 9.1%. The expansion of the source plane brings about not only the improvement of the thickness uniformity, but also a decrement of the efficiency and an enlargement of equipment.

• Transactions on Electrical and Electronic Materials
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• 제9권3호
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• pp.105-109
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• 2008

Electrical characteristics of organic light-emitting diodes were investigated by varying a hole-size in evaporation boat in the device structure of ITO/tris(8-hydroxyquinoline) aluminum$(Alq_3)$/Al. The device was manufactured using a thermal evaporation under a base pressure of $5{\times}10^{-6}$ Torr. The $Alq_3$ emitting organics were evaporated to be a thickness of 100 nm at a deposition rate of $1.5{\AA}/s$. A cylindrical-shaped evaporation boat was made out of stainless steel with a small size of hole on top of the boat. Several evaporation boats were made having a different hole size on top; 0.8 mm, 1.0 mm, 1.5 mm, and 3.0 mm. We found that when the hole size on top of the evaporation boat is 1.0 mm, the average roughness is rather smoother compared to the other ones. Also, luminance and external quantum efficiency are superior to the others. Compared to the ones from the devices made with the hole-size of 0.8 mm boat. The luminance and external quantum efficiency of the device made with the hole-size of 1.0 mm boat were improved by a factor of seventy and thirty three, respectively. Also operating voltage is reduced to 2 V.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.479-482
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• 2002

The purpose of this paper is to present and discuss some of evaporation and desiccation observed in field experiments. Surface desiccation of dredged material is basically changed by evaporation characteristics which is controlled by weather and ploughing interval, etc. This study shows that ploughing interval is important factors in desiccation of dredged soft clay. A series of field experiments with variation of ploughing interval were carried out to get evaporation effiency and strength increase. In this study, it is proposed that ploughing technique on the total surface area expedites surface desiccation efficiency. Desiccation efficiency is improved when ploughing technique is applied on the surface area.

• 전기학회논문지P
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• 제58권3호
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• pp.310-315
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• 2009

This investigation was performed to study the characteristics of electricity and heat transfer that occur in the cylinder of electrode type humidifier during the process of water evaporation. Measurements were made to obtain the amount of water evaporation, the consumption of electric power, electrical conductivity, etc according to the materials and shapes of electrode. When the humidifier was in non-drain controlled mode, the number and amplitude of current cycle per minute increased gradually with the lapse of time, whereas for drain controlled mode, it decreased about 40[%] after draining water. It was found that for non-drain controlled mode, the thermal efficiency of humidifier which used SS400, STS316 and wire net electrode type was about 95~96[%] and it was 2~4[%] higher than that of drain controlled mode. Also, it was shown that the thermal efficiency of humidifier which used neighboring six-phase electrode balanced electrically was 4[%] higher than that of existing six-phase type.