• 대한기계학회논문집B
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• 제25권1호
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• pp.124-132
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• 2001

This paper reports on the charge distribution measurements of submicron particles for three different charging mechanisms, which are spray electrification, bipolar ionization and corona discharge process, respectively. The number of elementary charges per particle was investigated by classifying and counting of a discrete mobility class. Charge distribution measurements were performed with NaCl particles generated from a collision atomizer for 0.01, 0.1, 1% NaCl solutions. Experimental results show than charge level of atomized NaCl particles is high and decreases with increasing the dissolved ion concentration. The charge level of the atomized NaCl particles can be reduced to that o Boltzmann equilibrium conditions by the bipolar ionization(Po(sup)210 bipolar ionizer). The charge level on NaCl particles passing through the corona discharge reactor is much higher than those of atomized or bipolar ionized NaCl particles. The evaluation of these measurements results in charge distribution of the submicron particles.

• 공기청정기술
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• 제15권2호통권57호
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• pp.14-23
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• 2002

• 한국분무공학회지
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• 제13권2호
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• pp.73-78
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• 2008

An experimental study was performed to explore the drop formation and atomization characteristics in electrohydrodynarnic atomization with flow rate, power supply, voltage frequency, and nozzle size. A basic electrohydrodynarnic atomizer equipment was developed for the analysis of spray visualization and tested for the exploration of relationship between several experimental parameters. In results, the varicose wave had been taken place and the small droplets had been generated less than outer diameter of nozzle on the conditions of 25G of nozzle, flow rate of 2 mL/min, and applied frequency of 50kV at AC power over 5kV voltage. The whipping motion had been grown at applied frequency of 400kV and AC power around 2kV voltage

• 한국분무공학회지
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• 제5권3호
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• pp.45-54
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• 2000

A novel electrostatic splaying method for solidifying a galvanized coating layer was studied. Our experimental results and computer simulations showed that electric field could assist the fine droplets to attach on the steel surface and change the sprayed droplets trajectory especially in the space near the steel surface. It was necessary to apply the electric voltage higher than - 20 kV to obtain the enough electrostatic attraction force between droplets and the steel sheet.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2003년도 하계 학술대회 논문집
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• pp.156-161
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• 2003

농약과 방제기가 개발되면서 적은 노력과 비용으로 넓은 면적의 작물을 병과 해충으로부터 보호할 수 있게 되어 수확량이 대폭 늘어나고 농사도 안정적으로 지을 수 있게 되었다. 이렇게 방제작업이 손쉽게 되었으나 농약을 필요량보다 적게 뿌릴 경우 병해충을 충분히 방제할 수 없고, 많이 뿌릴 경우 비용과 환경오염을 증가시키는 또 다른 문제점에 부닥치게 되었다. 현재 사용되고 있는 방제기로 농약을 살포할 경우 노출된 작물의 잎에서는 농약이 흘러내리는 반면 수관내부에 감추어진 잎이나 병해충이 주로 발생되는 잎 뒷면은 농약 부착이 미흡하다. (중략)

• 대한기계학회논문집B
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• 제22권8호
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• pp.1111-1120
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• 1998

Spray Drying Absorber(SDA) system, where the combustion product gas is mixed with atomized limestone-slurry droplets and then the chemical reaction of $SO_2$ with alkaline components of the liquid droplets forms sulfates, has been widely used to eliminate $SO_2$ gas from coal fired power plants and waste incinerators. Liquid atomization is necessary because it can maximize the reaction efficiency by increasing the total surface area and dispersion angle of the alkaline components. First, numerical calculations using FLUENT are carried out to investigate $SO_2$ concentration distribution and thus to calculate $SO_2$ removal efficiency. So to attain the optimized spray conditions, then an electrostatic spraying system is set up and spray visualization is performed to show the effect of an electric field on overall droplet size. Next, the effect of an electric field on the concentrations of $SO_2$ is experimentally examined. Field strength is varied from -10 kV to 10 kV and configurations of conduction charging and induction charging are utilized. Consequently, the electrostatic removal efficiency of 501 increases about 30% with the applied voltage of ${\pm}10kV$ but is independent of polarity of the applied voltage. It Is also found that the conduction charging configuration results in higher efficiency of $SO_2$ removal that the induction charging configuration. Finally, the effect of slurry temperature on $SO_2$ removal is studied. The temperature influences on the electrostatic removal efficiency of $SO_2$.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권9호
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• pp.388-394
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• 2003

Many toxic pesticides as aqueous-base sprays are dispensed for protection of food crops from pests into farm fields. When dispensed with conventional nozzles, a large portion of the spray is often lost by airborne drifts of droplets away and lack of deposition onto the plants due to rapid gravitational settling of droplets to the soil beneath. And target deposition efficiencies poorer than 20％ are often encountered in agricultural pesticides. An electrostatic spraying technology offers a very favorable means to increasing pesticides droplets deposition onto biological surfaces of living crops. In this paper a corona type spray nozzle, utilizing a set of corona charging devices and a pulsed droplet-charging voltage applied, has been proposed and tested its potential experimentally. As a result, it exhibits a large current deposition of aqueous pesticide sprays on the sensing target, which, however, promise to be as one of the effective electrostatic spraying nozzle.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권12호
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• pp.573-578
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• 2003

In this study, new type of induction charging system for electrostatic spraying was manufactured and proposed to improve the electrical safety and charging efficiency. And parameters of proposed system to generate the maximum deposition current with electrical safety were selected and investigated. The selected parameters were frequency of square pulse and thickness of insulation material, outer diameter of device and thickness and positions of electrode. Charging quantity of water drop was measured by deposition current detected from sensing plate indirectly. The maximum deposition current for each parameter were 3.5[uA] at the frequency of 15[kHz] and thickness of 0.25[mm] insulating layer. And maximum deposition currents were 2.8[uA] and 3.0[uA] at 25[mm] outer diameter of charging device and 0.25[mm] thickness of electrode each. Effects of electrode position from spraying nozzle on deposition current was a little.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.214-214
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• 2003

제지산업에 경쟁력을 부여할 수 있는 방법의 일환으로 제지용 도공안료의 표면개질을 시도하였다 은(Ag)이 항균력이 있다는 것이 여러 사람에 의해 증명된바 있으므로 이 은의 항균력을 제지용 무기안료에 이산화티탄과 함께 표면개질하고 다기능성 복합 항균분체를 설계하였다. 표면개질장치에 설치한 기상분사장치를 통해 은 용액을 고압기상분사로 TiO$_2$입자 표면에 Coating 하였다 이때의 분무각도는 60$^{\circ}$이고 오리피스 직경은 0.6mm, 분사 압력은 14kgf/$\textrm{cm}^2$ 이다. TiO$_2$에 은 용액을 기상분사하여 코팅시킨 후 표면개질 계산식에 의한 배합비로 모입자(clay, CaCO$_3$, PE)와 자입자(TiO$_2$)를 혼합하였고, 분체의 대전현상을 이용하여 모입자 주위에 자입자를 부착시킨 후, 고속기류중 충격력으로 표면개질처리를 하였다 표면개질 장치를 사용하여 제지용 무기안료 표면에 은용액이 코팅된 TiO$_2$를 개질 시켰다. 각종 물성(항균성, 백색도, 산란도)과 XRD, SEM 측정을 통해 기능성 항균분체의 실용방안 가능성에 대하여 조사하였다.

• Journal of Biosystems Engineering
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• 제29권1호
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• pp.21-28
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• 2004

Spraying is one of the most efficient methods for pesticide and insecticide control. Generally, orchard sprayers(aircarrier sprayer) are used for such applications. However, when an orchard sprayer is used, only 20% of total amount of spray deposits on the target. The rest of spray are not only wasted but are also potential sources of environmental pollution. The research far the development of electrostatic spraying system for orchard sprayer was conducted to develop the new pesticide application technology for the reduction of environmental pollution and f3r the production of safe agricultural products. The spray characteristics for nozzles with the different charging methods were tested and the effect of electrostatic charge was analyzed, in the laboratory experiments. The results of this study indicate that the capacitive type of electrostatic spraying nozzle exhibits a large current deposition of water sprays on the sample target. The covering area ratio by conventional spraying system was 10.2%, while that of electrostatic sprays with pulse induction charging method gave the increased covering area ratio by 4.3 times.