• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.81-84
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• 1999

순환유동층 (Circulating Fluidized Bed : CFB) 은 기존의 기포유동층에 비하여 높은 유속에서 조업되는 반응기로, 고속의 기체와 크기가 작은 고체 입자간의 긴밀한 접촉을 통하여 비교적 대규모의 여러 가지 화학적, 물리적 작업을 수행하는 유동층기술의 한 분야이다. 순환유동층은 1940년부터 공업적으로 이용되기 시작하였으며 현재에는 가솔린의 제조, 석탄의 연소, 가스화 등에 널리 사용되고 있다.(중략)

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.277-282
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• 2008

We developed fixed aerosol auto fire-extinguishing systems which are different from fire suppression systems like powder extinguisher or halon extinguishing system, etc. Fixed aerosol auto fire-extinguishing substances which are including solid alkali salts generated by combustion of solid composition. It represents high fire suppression ability due to particle friendly auto fire-extinguishing systems for the reason of excluding toxic substances in it's composition.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.8
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• pp.770-777
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• 2004

Fouling and cleaning tests are performed for a uniquely designed 7,000 ㎉/hr fluidized bed heat exchanger for exhaust gas heat recovery. Fuel rich condition is maintained in the combustor for a limited time period to generate soot that is to be deposited on the heat transfer surfaces (fouling) and 600 Um glass beads are circulated inside the heat exchanger system for cleaning and enhancing the heat transfer performance. According to the present experimental study, performance degradation mode could be monitored and the effect of particle circulation on the heat transfer improvement could be identified. Through the present study, it is demonstrated that circulating particles contribute not only to the fouling reduction in gas side, but also to the heat transfer enhancement of the unit, while other possible aging factors including water side corrosion seemed to contribute to the accumulated performance deterioration.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.7-10
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• 2009

The development and evaluation of solid propellant were performed for the turbopump pyro starter, which start up the liquid propellant rocket engine for the Space Launch Vehicle (SLV). Requirements for the turbopump pyro starter propellant include the production of low flame temperature, low burning rate and nontoxic gas to protect the mechanical corrosion or air pollution. This study describes the development of the solid propellant composition which is based on PCP binder. DHG (Dihydroxy glyoxime), which has advantages of oxygen balance and ignition, was used as coolant. The mechanical properties and burning rate of the propellants were measured. Finally, static fired test was performed to prove the possibility of development.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.12-18
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• 2014

A study of gas generator Fuel-Rich propellant for air-breathing propulsion system was performed in this paper. General solid propellant comprises a mean of 60% or more oxidizing agents. but, to develop the fuel-rich solid propellant increased the content of the metal fuel and reduced the content of the oxidizing agents by approximately 30%. Very high amount of heat per volume of fuel into the metal having the Boron was used. Amorphous Boron Powder was applied to propellant as beads type and it allowed to design more amount of metal fuel in the fuel-rich propellant. And the Combustion characteristics and properties of fuel-rich solid propellant according to the Boron-bead sizes were confirmed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.209-213
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• 2016

The characteristics of fluidization in a centrifugal fluidized bed with a 184 mm inner diameter, 50 mm width of the gas distributor was observed by photographs and experimental works using Cu-ZSM-5 zeolite catalysts with a mean diameter of $26{\mu}m$ and $32{\mu}m$ as bed materials at a rotor at 400rpm and 600rpm. Under these experimental ranges, the experimental results clearly showed the effects of the number of rotation of the rotor on the behavior of bubbles in the centrifugal fluidized bed. As the number of rotations of the rotor increased, the gas velocity at which bubbles begin to be formed also increased but the diameter of the bubbles decreased. In addition, the size of the bubbles in the centrifugal fluidized bed were relatively smaller than those in the conventional bubbling fluidized bed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.10
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• pp.1869-1876
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• 1992

The effect of particle property on FOD(foreign object damage) and strength degradation in structural ceramics especially, silicon carbide was investigated by accelerating a spherical particle having different material and different size. The damage induced showed significant differences in their patterns with increase of impact velocity. Also percussion cone was formed at the back part of specimen when particle size became large and its impact velocity exceeded a critical value. The extent of ring cracks was linearly related to particle size, however the impact of steel particle produced larger ring cracks than that of SiC particle. Increasing impact velocity the residual strength showed different degradation behaviors according to particle and its size. In the region the impact site represents nearly elastic deformation behavior, the residual strength was dependent upon the depth of cone crack regardless of particle size. However in elastic- plastic deformation region, the radial cracks led to rapid drop in residual strength.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.230.2-230.2
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• 2014

스퍼터링 공정은 보통 수백 eV로 가속된 이온에 의한 고체 타겟으로부터 입자의 방출로서 정의할 수 있다. 스퍼터된 입자는 열에너지보다 운동에너지가 크며 박막성장은 저에너지의 입자충격, 불활성 가스이온, 타겟부터 산란된 입자에 의하여 지배된다. 본 연구는 직경 2인치의 원형 Cr 타겟을 셔터를 닫고 예비 스퍼터링 할 때 셔터(SUS 304 0.1t)가 전자기력을 받아서 기계적으로 진동하는 현상을 규명하고자 하였다. 셔터의 하단부를 챔버의 중심축에 고정시켜서 타겟과 평행하도록 수 cm 떨어뜨려서 위치한 뒤 직류 마그네트론 플라즈마를 발생시켰을 때 DC power에 따라서 각각 움직임을 동영상촬영을 진행하였고, 셔터의 중심을 실로 매달아서 자유롭게 움직일 수 있도록 한 뒤 플라즈마가 발생했을 때 기계적인 움직임을 중점적으로 관찰했다. 움직임의 차이를 비교하기 위해서 셔터의 크기를 줄여가며 일정한 DC power에서 실험을 진행했고, 자세한 관찰을 위해서 초고속카메라(210 fps)로 짧은 순간의 변화를 비교했다. 실험조건은 5, 10 mTorr, DC power 30, 40, 50, 70, 100 W, Ar 30 sccm, 셔터의 크기 10, 20, 30, 40, 50, 60 mm로 실시했다. 압력이 낮아질수록, 셔터의 크기가 작을수록, DC power가 커질수록 움직임변화가 커졌고, 진동수가 빨라지는 것을 확인했다. F=qE=ma를 통해서 실험에서 촬영한 동영상을 근거로 거리측정을 통해 실험에서 얼마의 전기장이 인가되어 있는지 예측하였다.

• Solar Energy
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• v.12 no.1
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• pp.88-94
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• 1992

A small-scale solar collector and tracking system, using a Fresnel lens of $0.5m^2$, and novel compact fluidized-bed solar receiver[FBR] of closed type has been developed for high temperature solar gas heating. The FBR was improved in carrying over of SiC powder and thermo-siphon effect. The maximum outlet air temperature of 1140K and the maximum thermal efficiency of 64% were obtained. The present FBR's operated efficiently at extremely high temperatures in comparison with conventional solar receivers, composed of flat or tubular solid surfaces.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.333-339
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• 2000

현대사회의 공업화 및 도시화에 따라 NG(Natural Gas)를 포함하는 일반 가연성 가스의 누출에 의한 화재 및 폭발 재해는 매우 중요한 문제이다. 기체, 액체 및 분체가 단면적이 작은 분출구를 통해 공기중으로 이송 및 분출될 때 분출물질과 분출구와의 마찰로 인해 정전기가 발생한다./sup 1)/ 배관 내에 순수 NG가 이송·분출될 때의 대전량은 매우 작다./sup 2,3)/ 그러나, 배관 내에는 벤트스텍 등 외부에서 유입되는 먼지 또는 배관내의 부식에 의한 산화철(Fe₂O₃) 등의 분체가 포함될 수 있으며 이러한 분체가 천연가스 등과 함께 분출될 때 배관과의 마찰로 인해 대전량이 크게 상승된다./sup 3,4)/ 또한 분출되는 물질 구성입자들간 상호충돌에 의해서도 대전량은 더욱 증가하게 된다./sup 5)/(중략)