• 한국식품과학회지
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• 제34권5호
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• pp.924-926
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• 2002

분쇄땅콩의 결착력 증대 및 산패방지를 위한 유동층코팅 기술을 개발하고자, 유동충코팅공정의 흡입공기온도 및 분무압력이 분쇄땅콩의 유동층 코팅효율에 미치는 영향을 검토하였다. 흡입공기온도가 높을수록 코팅효율이 증가하였으며, 분무압력도 3 bar까지는 분무압력이 커질수록 코팅효율이 증가하는 경향을 나타내었다. 그리고, 덱스트린과 카제인나트륨로 구성된 코팅물질은 분쇄땅콩의 산패를 부분적으로 억제할 수 있음을 보여주었다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.18-19
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• 2006

To improve the properties of fine metal powder, such as particle size distribution and geometric standard deviation, this work was done at various atomizing conditions. The new atomization mechanism and the correlation equation were proposed to estimate the mean particle diameter.

• 대한기계학회논문집
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• 제14권5호
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• pp.1211-1221
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• 1990

본 연구에서는 CWM을 이류체 미립화기(twin-fluid atomizer)로 미립화 시켜 미립화에 크게 영향을 미치는 인자들로 믿어지는 공기분사압력, 부하도(loading), 미 분탄의 크기 그리고 CWM 방울 채집위치의 변화가 CWM 방울크기 분포와 CWM 방울안 미 분탄 존재유무에 미치는 영향을 연구의 목적으로 하였다.

• 대한화장품학회지
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• 제37권1호
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• pp.43-53
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• 2011

여드름 나노화장품(nanocosmetics) 개발을 위하여 azelaic acid-milk nano powder의 nanoencapsulation을 fluid-bed processor로 중심합성계획에 따라 유입공기온도($60{\sim}80^{\circ}C$) 분무속도(0.5 ~ 0.9 mL/min) 및 분무압력(1.2 ~ 2.0 kg/$cm^2$)을 달리하여 나노캡슐(nanoencapsule)을 제조하고, 나노캡슐의 품질특성을 조사하여 회귀분석을 실시하였다. 나노캡슐의 예측된 수율의 최대값은 70.97 %로 수율은 유입공기온도, 분무속도 및 분무압력 에 의해 크게 영향을 받고 있었다. 시료의 입자크기는 유입공기온도가 높고 분무속도가 빠르며, 분무압력이 낮을수록 커지는 것으로 나타났고, 생리식염수에서 나노캡슐의 용출율은 모두 유입공기온도 및 분무속도에 의해서 가장 많은 영향을 받고 있었다. 수분함량은 분무 속도가 증가하고 분무압력이 높아질수록 증가하였고, 수분활성도는 수분함량과 유사한 경향을 나타내었다. 기계적 색도인 L값과 b값은 유입공기온도가 높아질수록 증가하였다. 수율이 높고 입자크기가 작으며, 피부적합성 나노캡슐 제조의 최적조건은 유입공기온도 $67{\sim}73^{\circ}C$, 분무속도 0.6 ~ 0.8 mL/min 및 분무압력 1.8 ~ 2.0 kg/$cm^2$ 범위로 예측되었다. 이상의 예측범위 내의 임의의 점에서실제 실험한 실험치는 반응표면분석법에 의해 예측된 값과 유사한 경향을 보여 도출된 회귀식의 신뢰성을 검증할 수 있었다.

• 대한기계학회논문집
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• 제14권5호
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• pp.1330-1336
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• 1990

The factors to act on atomization of liquid fuel are viscosity, geometric shape of nozzle, atomizing pressure, etc. Most of high viscous liquid fuels show decrease in viscosity by raising the preheat temperature, but the viscosity of liquid fuel like CWM does not readily change with fuel temperature. As an experimental study to investigate the atomizing characteristics of CWM, CWM fuel is atomizing with a twin-fluid atomizer, and the effects of the geometric shape of spray nozzle on atomization are investigated by measuring the Sauter`s Mean Diameter (SMD) of CWM. The summarized results obtained in this study are as follows ; (1) As the ratio of the mass flows of atomizing air to that of fuel (W$_{a}$ /W$_{1}$) increases, 능 decreases when fuel temperature is constant. (2) At the ratio (t/d) 4 of thickness (t) of spray nozzle hole to the diameter (d) of the hole, there is the best atomization. And SMD decreases when t/d is between 1 to 4 and increases when t/d > 4.

• 대한기계학회논문집
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• 제15권2호
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• pp.618-629
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• 1991

The purpose of this experiment is to understand the distribution of coal particles inside CWM droplet which is believed to be a very important factor controlling the flame stability. CWM slurry is atomized by an air assisted twin fluid nozzle. An experimental rig is designed and fabricated. The mean size of coal particle distribution in CWM slurry, atomizing air pressure, coal particle loading in slurry and sampling position inside spray are main experimental variables. The atomized CWM droplets are sampled on the thin white layer of magnesium oxide by the emergency sampling shutter. The sampled coal particles on magnesium oxide layers are collected into test tubes and dispersed completely by Ultra-Sonicator. The size distribution of coal particles inside droplets are measured by Coulter Counter. The presence of coal particle inside the impressions of droplets on magnesium oxide layer are investigated by photo technique. There are quite many droplets which do not have any coal particles. Those are just water droplets, not CWM droplets. The population ratio of droplets without coal particles to toal number of droplets is strongly affected by the mean size of coal particle distribution in slurry and this ration becomes bigger number as the mean size of coal particles be larger. The size distribution of coal particles inside CWM droplets is not even and depends on the size of droplet. Experimental results show that the larger CWM droplets has droplets has bigger mean value of particle size distribution. This trend becomes more evident as the atomizing air pressure is raised and the mean size of coal particles in CWM slurry is bigger. That is, the distribution of coal particles inside CWM dropolets is very much affected by the atomizing air pressure and the mean size of pulverized coal particles in CWM slurry.

• 한국대기환경학회지
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• 제12권4호
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• pp.449-457
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• 1996

The main purpose of this study was to investigate sulfur dioxide removal performance of flue gas desulfurization system utilizing a Spray Absorption/Drying Reactor. In this system, the size of droplets was considered the most significant factor and tested using a PDA system. Lime slurry flow rate, operating temperature, calcium/sulfur (Ca/S) ratio and applied air pressure were selected as major operation variables and tested/analyzed in terms of system performance. The results are as follows. 1. The $SO_2$ removal efficiencies were 49%, 74%, 85% for Ca$(OH)_2$ slurry flow rate of 10, 20, 30 ml/min, which implies that the increase of slurry flow rate improves removal efficiency. The optimum slurry flow rate in this study was, however, considered 20 ml/min because of constraints of system troubles and absorbent utilization. 2. As Ca/S ratio increased, $SO_2$ removal efficiency was observed to increase. 3. As air pressure, at the atomizing nozzole, increased from 3 to 5 $kg/cm^2, SO_2$ removal efficiency increased from 74% to 80%, because of droplet size reduction due to pressure increase during atomizing process and the increase of surface area, helping mass transfer between gas and liquid phase.

• Advances in materials Research
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• 제6권4호
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• pp.343-348
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• 2017

High-pressure gas atomization was employed to prepare the Fe-based $Fe_{50}Cr_{24}Mo_{21}Si_2B_3$ alloy powder. The effect of flow rate of atomizing gas on the median powder diameter was studied. The results show that the powder size decreased with increasing the flow rate of atomizing gas. Fe-based alloy coatings with amorphous phase fraction was then prepared by high velocity oxygen fuel spraying (HVOF) of gas atomized $Fe_{50}Cr_{24}Mo_{21}Si_2B_3$ powder. Microstructural studies show that the coatings present dense layered structure and low porosity of 0.17% in about $200{\mu}m$ thickness. The Fe-based alloy coating exhibits an average hardness of about 1230 HV. Our results show that the HVOF process results in dense and well-bonded coatings, making it attractive for protective coatings applications.

• 대한기계학회논문집B
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• 제20권7호
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• pp.2267-2276
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• 1996

공정산업분야 및 분무연소분야에서 많이 사용되고 있는 2유체 분무기에서 출구 초음속유동의 가시화와 하류의 가스압력 측정 결과로부터 다음과 같은 결론을 얻었다. 1) 과소팽창 또는 과대팽창 초음속노즐 유동에서 출구 Mach수가 일정한 경우, 유동이 박리하지 않는다면 가스의 정체압력(유량)이 증가함에 따라 노즐출구에서 충돌정체점까지의 길이와 초음속 유동영역의 길이는 증가한다. 2) 스피팅 현상은 액체공급관 출구의 흡인압력은 분사가스압력이 증가함에 따라 단조증가하지만 분사가스압력이 0.5MPa이상이 되면 증감현상이 커지며 돌출형 노즐에서 유동박리시 급격히 증가한 다음 거의 일정하게 유지된다. 4) 액체공급관 하류축상의 압력변화는 출구의 음압에서 충돌정체점까지 상승한 다음 급강하하고 충격파 세포상의 구조에 따라 진동하면서 대기압에 도달한다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 제26회 KOSCO SYMPOSIUM 논문집
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• pp.173-178
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• 2003

An experimental study is conducted to investigate the effects of fuel temperature on the spray characteristics of a dual-orifice type swirl injector which is used in gas turbines. The major parameters affecting spray characteristics are fuel temperature and injection pressure entering into the injector. Fuel temperature is shown to have strong influence on the spray characteristics especially at a lower temperature. In this study, fuel temperature is varied from $30^{\circ}C$ to $120^{\circ}C$ and injection pressure is altered from 3 to $7 kg_{f}$ /$cm^{2}$. Two kinds of fuel, which have different surface tension and viscosity, are chosen as an atomizing fluid. As a result, injection instability occurs in the low temperature range due to icing phenomenon and the change of fuel properties. As the injection pressure increases, the kinematic viscosity range for stable atomization becomes wider. The factor controlling the SMD of spray is substantially different depending on the fuel temperature range.