• 공업화학
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• 제26권5호
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• pp.549-556
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• 2015

한약재에서 추출한 해충기피용액과 실리카를 혼합하여 해충기피 실리카 졸을 제조하고, 분무건조법을 이용하여 마이크로 단위의 해충기피용액이 포함된 다공성 구형 분말을 제조하였다. 분무건조법을 통해 제조된 해충기피 분말의 특성분석을 위해 해충기피 졸의 농도(해충기피용액, 실리카) 및 분무 건조 장비의 조건에 따라 분말 모폴로지, 입자크기별 입경분포, 열적 안정성 분석을 실시하였다. 해충기피 졸의 농도가 4, 7 wt% 및 10 wt%일 때 각각 평균 입자 크기가 8.3, $9.5{\mu}m$ 및 $11.7{\mu}m$ 순으로 농도가 증가할수록 분말의 직경이 커졌다. 반면에 빠른 가스 주입속도 상태에서 노즐입구온도 및 용액주입속도 증가에 의한 분말 입경의 증가는 미미하였다. 또한, 열중량 분석법을 통하여, 구형의 다공성 분말 안에 해충기피 용액이 담지 되어있고, 이들은 $200^{\circ}C$까지 열적 안정성이 확보됨을 확인하였다. 분무건조를 통한 해충기피 분말은 평균 $9{\sim}10{\mu}m$이고, 열적 안정성을 가지므로 컴파운딩 및 필름제조공정에 응용이 가능할 것으로 기대된다.

• Journal of Biosystems Engineering
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• 제21권4호
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• pp.467-473
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• 1996

Ultrasonic energy was applied for atomizing rice-bran oil which is a highly viscous bio fuel. Six different nozzles, an injection simulator, and an ultrasonic generator system were designed and constructed for the experiment. An immersion liquid method was used for the measurement of injection droplet sizes. The characteristics of injection droplets was investigated with respect to the numbers of the droplets with diameters ranging from 5$\mu$m 50$\mu$m and to the Sauter mean diameter. The results showed that the ultrasonic energy was effective for the improvement of the atomization of the injection droplets for all the factors such as type of nozzles, nozzle opening pressures, and collection distances.

• 자원리싸이클링
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• 제11권5호
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• pp.24-29
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• 2002

철강압연공장에서 산세공정중 발생하는 산화철의 색상을 개선하기 위하여 배소로 조업과 색상혼합공정을 연구하였다. 배소로 조업에서는 조업온도, 폐산장입량, 폐산분사 노즐수에 대하여 검토하였으며, 색상혼합공정에서는 산화티탄, 실리카, 괴타이트를 색상혼합재로 검토하였다. 배소로 조업에서는 조업온도를 낮게 할수록 산화철의 명도가 개선되었으며, 색상혼합공정에서는 괴타이트 첨가 경우에 제일 많이 산화철의 적색 및 명도가 개선되었다.

• 오토저널
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• 제14권5호
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• pp.41-53
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• 1992

The main purpose of this study is to investigate the atomizing characteristics of a two phase spray by using a liquid column type coaxial nozzle. The experiments have been carried out to analyze the atomization behavior, the droplet size distributions, and the statistical properties of droplet size distributions. Immersion sampling method and the image processing technique were adapted for the measurements of particles, and the distributions of the droplet sizes were statistically analyzed. In the experiments, the mass ratio defined as Mr= $M_{\sigma}$/ $M_{1}$ has been changed from 1.0 to 3.4 and the measurements have been performed along the axis of the spray. As a result of this experimental study, the distributions of droplet size were satisfied with the Log-Normal distributions and arithmetic mean diameter and deviation of mass ratio. Droplet volume-surface mean diameter was denoted by a exponential function of mass-ratio and the exponent was denoted by linear relation according to the central axis from the nozzle. Dispersions, skewness factors and flatness factors had comparatively constant values regardless of mass ratio and location.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1997년도 하계 학술대회 논문집
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• pp.141-149
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• 1997

Structural characteristic of a rice polisher of small size was analyzed to improve its performance and to utilize such data in developing a rice polisher of large size. Spraying characteristic of nozzles which were used for rice polishing was evaluated by a machine vision system. Internal pressure of the polishing chamber was also measured according to outlet resistance, water spraying, and roller shaft speed. In addition, the performance of the polisher was analyzed based on whiteness and broken ratio according to operating conditions.

• 오토저널
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• 제15권1호
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• pp.37-44
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• 1993

Fuel injection system is an important tool in the exhaust emission and performance of a diesel engine. Effects of the fuel injection system in diesel combustion was investigated experimentally by measuring the performance and analyzing the combustion phenomena in a D.I. diesel engine. The selected injection parameters were nozzle opening pressure, nozzle projection length, and nozzle spray angle. From the measured results, it is shown that the fuel injection pipe diameter is an effective means to improve engine performance in a middle and high speed range and the 2 stage spring nozzle holder has the advantage of increasing the engine performance due to the initial injection pressure in a low speed range. It has been also shown that increasing nozzle opening pressure resulted in decrease in smoke, but increase in NO$_{x}$ from the engine.e.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1703-1708
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• 2003

The present study investigates the effect of injection angle of water mist on fire suppression characteristics by numerical simulation. In order to validate the temperature field by numerical simulation, the predicted results are compared with experimental data. It shows that the temperature difference between measurements and predictions are within $10^{\circ}C$ Numerical simulations of fire suppression are performed for 4 different injection angle($60^{\circ}$, $90^{\circ}$, $120^{\circ}$, and $180^{\circ}$). The grobal mean temperature over the fire compartment decrease with increasing of spray angle. The result shows that the heat transfer between droplets and gas phase are enhaced with the increasing of spray angle. Near the fire source, temperature field by the wide spray angle is slightly higher than that of narrow injection angle because of direct cooling of fire source.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.307-308
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• 2006

Recently, fire extinguishing systems based on water mists have been attracting public attentions in marine engineering. Performance of the fire extinguishing systems is influenced by the size and distribution of spayed water mists. Droplet analyzing method based on image processing technique for measuring droplet size and distribution has been developed. The morphological method based on partial curvature information of pre-processed images was adopted for recognition and separation of overlapped particles. Tested results show that the present method may be reliable for the analysis of the size and distribution of droplets produced by water mist spay flow.

• 한국안전학회지
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• 제21권6호
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• pp.46-54
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• 2006

Fire extinguishing experiment was conducted with water mist nozzle in case of the pool fire, cascade fire and spray fire on flammable liquid of class B whether water mist system can be effective system for power transformer fire scenario. In the event of a pool fire, flow rate and time to extinguish was inclined to be increased according to the obstruction rate of ignition space. Furthermore, the performance of fire extinguishing depended upon the spraying angle of the nozzles. In case of cascade fire, the effect of extinguishment was began to show from a combustion pan filled with fuel and fuel flowing plate later on.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 추계학술대회 논문집(Proceeding of the KOSME 2001 Autumn Annual Meeting)
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• pp.8-14
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• 2001

The purpose of this study is to elucidate heat characteristics according to inclination angle of the hot flat plate at the spray cooling. As results of this experiment, the heat flux, the heat transfer coefficient and the cooling speed are increased as the liquid volume flux and subcooled temperature go up. And as the inclination angle of the heat transfer surface is increased, the cooling speed on the inclined flat plate becomes faster. It means that the cooling ability is increased because droplets were excluded by gravity.