Various electronic control parts and devices installed in electric vehicles have greatly improved the convenience of occupants, but electromagnetic waves emitted from electronic devices have greatly increased concerns about malfunctions, deterioration of performance, safety accidents, etc. There are two models of analysis. Case A is symmetrical about one axis of rotation. Case B has two axes of rotation. In this study, a flow analysis was conducted to find excellent flow conditions in the mixing process to develop a paint with excellent electromagnetic shielding and thermal insulation performance. The results of the flow analysis are reflected in manufacturing specifications and are intended to be used to develop high-quality systems.

This study is carried out to analyze the velocity distribution for each location and the uniformity index according to straight distance on exit side by changing the design factors of branch pipe connected to 180° circular mixing-tee using RSM(Reynolds Stress Model) turbulence model. As the results of the flow characteristics according to hydraulic diameter, the velocity profiles in the 90° sectional area are generally similar. In the 180° section, the maximum velocity point shows Y/D=0.7~0.8 after rapid increase of the flow velocity. In the result according to the distance away from inlet, the maximum velocity point in the 90° sectional area is located in outer side of the curved pipe as the distance away from inlet increases. In the 180° sectional area, the maximum velocity point is showed in Y/D=0.7~0.8 after the rapid increase of the flow velocity regardless of the variation of branched distance. In case of inclined angle, the maximum velocity point in the 90° sectional area is located in outer side of the curved pipe as the inclined angle increases. In the 180° sectional area, the maximum velocity point is observed in Y/D=0.8 regardless of the inclined angle. In addition, the uniformity index of flow velocity shows that it is stabilizing after approximately L/D=40 away from the end of the curved pipe regardless of the flow factors in the branch pipe.

In this study, the temperature, the absolute humidity, and the turbulent flow characteristics of exhaust air and supply air in the mixer were studied while changing the shape of the mixer of the white smoke reducing heat exchange system. Using Solidworks, the mixer of the white smoke reduction heat exchange system was created by 3-D model. Also, the mixed flow of supply air and exhaust air inside the mixer under the uniform inlet conditions was computed, using the solidworks flow simulation. Two types of improvement models were selected by using a perforated plate and a guide vane as a turbulent mixing flow control method of the mixer. The mean temperature and mean absolute humidity of the mixture were greatly decreased according to the internal shapes of Case 1, 2, and 3. The temperature difference between the inlet and outlet of the mixer Case 3 was 26℃. The exit temperature and absolute humidity reduction rates of Case 3 were 26.2% and 48.1%, respectively, compared with Case 1.

This study was successfully achieved out the optimized system for dispersing and mixing condition of resin liquid. The flow analysis was simulated according to the shape of the impeller and the stirring tank using ANSYS software and optimized in advanced design. As a result, it was confirmed that the shape and double number of the impeller on the flow field are influenced better effects in a range of mixing and diffusion areas comparing to single number of impeller. It was considered that stirring was performed more quickly and efficiently under the condition of double numbers and saw tooth type impeller. This result can be applied practically for the mixing tank in the industrial application and avaliable used to make a new system for painting equipment.

The MLCC electronic materials are used to make many industrial parts, for instance, such as smart phone, radio, LCD TV and so on. The screen ways and the rotor ways are known as methods that form electrode in MLCC. In these days, rotor ways have been frequently utilized because of its stability of quality. In this study, mixing characteristics for the inside of barrel of planetary mixer driver were investigated by numerical analysis using k-ε model of unsteady state, including effects for rotation and revolution. As the results, it showed that the flow of radius direction was mixed with regular pattern depending on time, however, the flow of longitudinal direction was mixed with same pattern regardless of time.

The flow acting on a confined jet flow can be represented as a conventional turbulence flow with its complex phase and characteristics. This is still effectively applied in a variety of industries, for example in ejectors. In this study coaxial confined model made of transparent acrylic pipe and driving water nozzle in order to figure out of recirculation flow near the wall of pipe and prove how flow in the pipe can be developed. It was revealed that length of the recirculation flow adjacent to wall of pipe was characterized to be larger when Reynolds Number is getting bigger.

Translucent alumina is a potential candidate for high temperature application as a replacement of the glassor polymer. Recently, due to the increasing demand of high power light emitting diode (LED), there is a growing inter-est in the translucent alumina. Since the translucent property is very sensitive to the internal defect, such as voids insideor abnormal grain growth of sintered alumina, it is important to fabricate the defect-free product through the fabricationprocess. Powder injection molding (PIM) has been commonly applied for the fabrication of complex shaped products.Among the many parameters of PIM, the flowability of powder/binder mixture becomes more significant especially forthe shape of the cavity with thin thickness. Two different positions of the gate were applied during PIM using the disctype of die. The binder was removed by solvent extraction method and the brown compact was sintered at 1750oC for3 hours in a vacuum. The flowability was also simulated using moldflow (MPI 6.0) with two different types of gate.The effect of the flowability of powder/binder mixture on the microstructure of the sintered specimen was studied withthe analysis of the simulation result.

판형 열교환기의 유로 형상을 모사한 유동장을 대상으로 입자영상유속계를 이용 하여 속도를 계측하였으며, 시계열 속도분포를 고찰하였다. 그 결과 삼각형상 그루브 내의 유동형태는 채널흐름으로부터 전달받은 전단응력이 그루브 내부를 순환하는 회전에너 지로 전환되면서 강제와류와 유사한 달걀형의 일그러진 타원형의 주순환류가 존재하며, 레이놀즈수의 증가에 따라 전단혼합층의 상대적 영향이 감소하였다.

By the end of 2012, the recycled proportion of domestic waste tires was 287,330 ton (93.9%) of the amount of waste tires discharged (305,877 ton). The waste tires have been reused for heat supply, material recycling and other purposes; the proportions are 50.1%, 20.7% and 23.1%, respectively. In the case of heat supply, waste tires are supplied to cement kiln (104,105 ton, 68%), RDF manufacture facilities (47,530 ton, 31%) and incinerators (1,923 ton, 1%). Recently, there has been an increase in the use of waste tires at power generation facilities as an auxiliary fuel. Thus, physico-chemical analysis, such as proximate analysis, elemental analysis and calorific value analysis have been carried out to evaluate potential of waste tires as an auxiliary fuel in Korea. The LHV (Lower Heating Value) of waste tires is approximately 20% higher than that of coal, at an average of 8,489 kcal/kg (7,684 ~ 10,040 kcal/kg). Meanwhile, the sulfur content is approximately 1.5wt. %, and balance of plant (e.g. pipe line, boiler tube, etc.) may be corroded by the sulfur. However, this can be prevented by construction and supplementation with refractories. In this study, TDF (Tire Derived Fuel) produced from waste tires was co-combusted with coal, and applied to the CFB (Circulating Fluidized Bed) boiler, a commercial plant of 100 tons/day in Korea. It was combined with coal, ranging from 0 to 20wt. %. In order to determine the effect on human health and the environment, gas emission such as dioxin, NOx, SOx and so on, were continuously analyzed and monitored as well as the oxygen and carbon monoxide levels to check operational issues.

신재생에너지원 중 가장 큰 부분을 차지하고 있는 폐기물의 경우, 매립 등으로 폐기되고 있다. 특히 슬러지와 같은 저급연료는 에너지원으로 활용되지 못하고 70%이상 해양 투기되고 있으나 런던협약 이후 해양투기 금지로 인해 육상처리방안의 마련이 시급한 실정이다. 또한, 현재 유일한 온실가스 감축기술인 CCS(Carbon Capture and Storage)의 경우 연소공정의 후단에서 배출가스 내에 질산화물 등 다양한 오염물질의 혼입으로 회수되는 CO₂ 등의 순도가 낮아져 경제성의 확보가 어려운 실정이다. 따라서 연소공정에 투입되는 과잉공기 대신 순산소 연소(Oxy-fuel Combustion)를 시행하여 열원을 최대로 회수함과 동시에, FGR(Flue Gas Recirculation)을 통해 배출가스를 연소로 내로 재순환함으로 높은 농도의 CO₂흐름을 만들어 대기로 배출되는 CO₂를 분리하거나 고순도 저장이 가능한 CCS ready기술을 개발하여 국제적인 온실가스 감축의무화에 대비하기 위한 공정기술을 개발하고자 하였다. 본 연구에서는 연료로 적용할 슬러지와 혼합연료의 기초특성분석을 실시하였으며, Cold bed과 이론적인 계산을 통해 순환유동층을 형성하기 위한 유량을 도출하였고 이에 따른 연료 투입량을 산정하였다. Cold bed 실험을 통해서 최소유동화속도를 도출하였고, 유량과 유체의 성상 (Air, Oxy21%, Oxy25%, Oxy30%, Oxy40%) 따른 외부고체 순환률과 압력구배를 비교하였다. Hot bed를 통해서는 유체성상에 따른 온도구배를 비교하였고, 슬러지와 혼합연료 (30%, 50%, 70%)에 따른 온도구배와 주요 배가스 (CO₂, CO, O₂, NOx, SOx)를 비교하였다. 또한 FGR 운영을 통해 주요 배가스의 변화를 확인하였다. 하수슬러지의 기초특성분석결과 발열량은 약 3,000 kcal/kg, 원소분석은 탄소 28.64%, 수소 4.82%, 산소 18.94%, 질소 4.51%, 황 0.44%, 공업분석은 수분 7.32%, 휘발분 45.11%, 고정탄소 12.25%, 회분 35.32% 함량을 보였다. 펠렛의 기초특성분석결과 발열량은 약 4,200 kcal/kg, 원소분석은 탄소 48.59%, 수소 6.08%, 산소 42.03%, 공업분석은 수분 8.68%, 휘발분 74.16%, 고정탄소 16.83%, 회분 0.29% 함량을 보였다. 유속에 따른 Riser 층내 압력강하는 0.104 m/s에서 최소 유동화속도를 관측하였으며, 1.9 m/s 이상의 공탑속도에서 고속유동층으로 전이되는 것을 확인하였고, 2.4 m/s 이상의 공탑속도로 운전하는 것으로 판단하였다. 순환유동층 전이에 필요한 유량의 연료투입량은 13 kg이고, 연소 유체 성상에 따른 온도구배는 Oxy 비율이 높아질수록 배가스의 온도가 높게 유지되었다. 각 조건별 배가스 분석결과 고농도 CO₂ 농축가능성을 확인하였다.

가공이나 저장 중 쉽게 산화되는 특성을 갖는 비타민 C의 안정성과 가공적성을 향상시키고자 Zein-DP와 HPMC-FCC를 코팅제로 한 유동층 코팅법을 이용하여 코팅한 비타민 C 분말의 품질 특성에 대하여 조사하였다. 유동층 코팅은 비타민 C의 입자크기()와 코팅액의 혼합비(1:1.6, 1:2.5, 1:3(w/w))를 달리하여 실시하였다. 코팅효율은 의 경우가 보다 높았고 코팅액의 혼합량이 많을수록 감소함을 보였다. 코팅된 필름의 두께는 의 경