• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1363-1364
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• 2011

• 한국기계가공학회지
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• 제11권6호
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• pp.183-188
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• 2012

This study was carried out to design the spray nozzle tip for airless spray coating. Airless spray coating is the process of coating an object with a liquid spray of paint or other fluid. The nozzle tip controls the fluid flow rate and creates back pressure in the system. The nozzle tip also defines the spray pattern by the size and shape of the orifice. The spray pattern of nozzle tip was investigated numerically using ANSYS CFX ver. 14.0. It was observed that performance result of designed nozzle tip was correspond well, compared with that of GARCO nozzle tip.

• 한국해양공학회지
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• 제28권2호
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• pp.177-184
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• 2014

Heavy duty coating is playing an important role in the field of heavy industry in the development of the shipbuilding and plant industries. Heavy duty coating has the very important function of protecting steel under serious corrosive conditions. The airless tip used for heavy duty coating is an essential part that determines the spray pattern of the paint. This research investigated the injection properties of three airless tips(numbers 521, 523, and 525) by using particle image velocimetry(PIV). The velocity and turbulent intensity according to pressure change with each tip type were investigated by using PIV. If the pressure is greater, the turbulent intensity becomes stronger and the break up of particles becomes bigger as the tip number gets smaller. The velocity is the fastest in the center and decreases in the radial direction.

• Journal of Electrochemical Science and Technology
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• 제8권2호
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• pp.155-161
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• 2017

Carbon felts were prepared under various thermal conditions to improve the electrochemical properties of vanadium redox flow batteries. The number of C-O and/or C-OH functional groups on the surface of the electrodes treated under airless conditions was much larger than that of the untreated and partially oxygen-treated electrodes. The carbon felt treated under airless conditions had the lowest surface area. The overall kinetic properties of the redox reaction were greatly improved for the carbon felt treated under airless conditions; i.e., the reversibility of the anodic and cathodic reactions associated with the $VO_2{^+}/VO^{2+}$ couple became more reversible. Single-cell tests indicated that the carbon felt exhibited an excellent discharge capacity of $3.1Ah{\cdot}g^{-1}$ at $40mA{\cdot}cm^{-2}$, and the corresponding Coulombic, voltage, and energy efficiencies were 89.5%, 91.8%, and 82.2%, respectively.

• 항공우주시스템공학회지
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• 제4권2호
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• pp.1-9
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• 2010

An airless tire has advantages over the conventional pneumatic tire in terms of flat proof and maintenance free. According to the recently disclosed inventions on the airless tire, non-pneumatic tire (NPT) consists of the flexible polygon spokes. Considering the NPT structure, the spokes undergo the tension-compression cyclic loading while the tire rolls. Therefore the spokes of NPT are required to have both stiffness and resilience under the cyclic tensile-compressible loading. In general, if a material has a high stiffness, it shows a low elastic strain limit. In this paper, using the auxetic honeycomb structure with negative poissons's ratio, the spokes of NPT tire are designed to have both stiffness and resilience. Finite element based numerical simulation of the contact pressure of a NPT is carried out with ABAQUS.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.786-791
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• 2003

We have studied on the main causes of pressure drop in the paint hose under the spraying with airless spray pump and suggest calculation method for selecting the optimum pressure drop during the spraying. Among many factors contributing the pressure drop during the airless spraying procedure of paint, some of the key factors and the correct method for checking pressure loss between airless pump and spray gun are addressed. We have developed pressure loss calculation method which depending on hose length and diameter, viscosity and flow rate in the painting hose during the spraying. also we have developed calculation equation for the expected spray tip flow rate which depending on pressure and specific gravity and tip size.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.603-604
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• 2006

The worker who is responsible for Airless Pump maintenance have a high possibility to suffer from WMSDs, because a height of Airless Pump workbench is too low. In this paper, I'm going to introduce a research about 1) analysis of working environment through a interview with an actual field worker, 2) Ergonomic simulation modeling of an Ariless Pump worker to suggest a advanced working environment and a working instructions. I have used a DELMIA S/W as a tool for ergonomic simulation and performed a posture & activity to analyze a RULA methodology. Applying the Digital Human Simulation to analyze working posture would be helpful to preventing WMSDs.

• Corrosion Science and Technology
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• 제14권2호
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• pp.59-63
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• 2015

Airless spray which is widely used for painting to ship blocks and hull sides is the coating method for attaching atomized paint material to the substrate using spray tip nozzle with compressed air. When the paint material which has high solid contents such as epoxy primer paint is atomized by passing through spray tip nozzle with high pressure, the nozzle composed of tungsten carbide(WC) undergoes the erosive wear, leading to widening of nozzle hole. The deformation of nozzle hole induces improper spray pattern and coating failures such as finger pattern and sagging because the conditions of spray pump pressure and paint flow rate for developing full spray pattern are changed. In this study, an appropriate replacement cycle of spray tip was predicted by measuring the erosive wear tendency as increasing the spraying time of epoxy primer paint.

• 한국산학기술학회논문지
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• 제21권1호
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• pp.487-493
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• 2020

최근 환경부의 강화된 규제로 건축물 아파트 등 산업시설을 도장함에 있어 페인트를 유압에 의해 자동으로 이송시켜 스프레이식으로 도장하는 기존 에어리스 방식의 사용을 금지하였다. 따라서 기존의 에어리스 도장장치에 스프레이 대신 부착하여 사용할 압송롤러개발이 필요한데, 현재 개발되어 판매 중인 압송롤러는 롤러를 구성하는 SUS배관 및 드럼베이스의 홀 설계에 대한 자세한 연구 사례가 없어 그 효율성이 의심이 되는 바이다. 특히, 롤러를 이용한 도장 시롤러 양단에 페인트가 충분히 공급되지 못하면 도장 후 붓을 이용한 재작업이 필요하게 되므로, 롤러 양단에 페인트가 잘 유입될 수 있도록 드럼베이스 홀을 분포시킬 필요가 있다. 본 연구에서는 SUS배관 및 드럼베이스에 가공되는 홀의 형태가 페인트의 유입양상에 미치는 영향을 알아보고 보다 효율적인 홀 설계 방안을 제시하기 위하여 SUS배관 및 롤러에 대하여 전산유체해석을 수행하였다. 해석결과 SUS배관에서의 홀 배치는 배관에 균일하게 배치하는 것이 균형 있게 페인트를 유입시키기에 좋고, 드럼베이스의 경우는 홀을 드럼베이스 양단에 밀집하여 가공하면 페인트가 롤러 양단에 더 잘 유입시킬 수 있음이 검증되었다.

• 한국식품영양과학회지
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• 제28권4호
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• pp.890-894
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• 1999

Microencapsulation of anchovy oil as a core material in sodium alginate as a wall material was inves tigated. Microencapsulation was accomplished by injecting an oil/water emulsion, consisting of a mixture of liquefied sodium alginate and emulsifier, under high pressure through an orifice submerged in a calcium lactate solution. Microcapsules suspended in a dispersion fluid were observed under a fluorescence mi croscope to verify the presence of the capsules and to note coalescence or degradation of the capsules. Optimum conditions for microencapsulation of anchovy oil were obtained when 1.0% aqueous solution of sodium alginate contained 3% of a 1:1 ratio of ESPR 25(polyglycerine＋polylinoleate) and TW 20(sorbitan laurate＋ethylene oxide) as an emulsifier in terms of capsule size and size distribution, and emulsion stability. The airless sprayer produced microcapsules with a diameter between 15.9 and 73.9 m with different concentration of a wall material. The optimum mixing ratio of wall material to core material was 90:10(wt/wt). 0.2% calcium lactate was appropriate as a dispersion fluid.