• 한국유체기계학회 논문집
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• 제12권5호
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• pp.25-32
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• 2009

A study is conducted to improve the suction performance on suction devices which are used to remove polluted air generated by welding or machining process in a spacious working place of industry. Air-curtain is applied around the inlet of suction duct to interrupt the inflow of fresh air from the downstream region where is located opposite to the polluted air source. Two different air-curtain devices, such as a $45^{\circ}$ backward and a fully backward, are adopted. Suction region is experimentally investigated by measuring the suction velocities using a hot-wire anemometer. Contours of the suction velocity are compared with the computed results. The suction condition is selected to 110,000 Reynolds number which is widely used on typical suction devices, and a width of blowing passage for creating the air-curtain is chosen to 9.38% of the suction duct diameter. The experimental results show that the suction performance obtained with the $45^{\circ}$ backward air-curtain was better than that obtained with the fully backward air-curtain. On the suction duct using the $45^{\circ}$ backward air-curtain, the suction region estimated on basis of the 0.4m/sec is improved by 66% at the same input power.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.962-966
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• 2004

Suction transfer system with air suctioning is widely used and continuously developed in production automation. Air suctioning has some drawbacks in use. To generate vacuum in the suction cup with air suctioning, complex of mechanical component like as air compressor, air tube, air value is need, and it needs continuous air supply. And if the failure of the suction in a cup in the multi-suction cup system which is generally used occurs then the suctions of all of the cup will be fail. To overcome these drawbacks, new suction mechanism which uses permanent magnet for the movement of the suction cup is proposed. The proposed mechanism activates each suction cup separately, so the air leakage of a cup is not critical. The proposed suction system wasdesigned and fabricated in real world. With some experiments, the usability and performance of the suction mechanism was proved. The strong points of the proposed suction mechanism are simple structure, high energy efficiency, and discrete energy supply.

• 대한기계학회논문집A
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• 제29권12권
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• pp.1645-1652
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• 2005

Pick-and-place systems using suction cups have been being widely used and continuously developed in production automation. There are, however, some drawbacks in constructing such systems. One of them is that it generates high level noise due to air compressors. And the system must have complex constitutions of mechanical component such as air compressors, air tubes, air valves, etc. Moreover, it needs continuous air supply to maintain vacuum in suction cups. If there is a failure in any suction cup, the total suction system may fail owing to air leakage. To overcome these drawbacks, we propose PMS (Permanent Magnet Suction) mechanism which has permanent magnets for vacuuming suction cups with no air compressor. The basic concept of PMS mechanism is to rotate permanent magnets with fixed angle. Simple rotation of permanent magnets changes the direction of the magnetic force applied at the suction cups. Since each suction cup has no direct connection with any of the others, the air leakage at one suction cup is not critical. The proposed suction mechanism was designed and fabricated. With some experiments, the feasibility and performance of the PMS mechanism was shown. The strong points of the PMS mechanism are in its simple structure, generating low noise, high energy efficiency, and no need of continuous energy supply.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제26권3호
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• pp.260-264
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• 2024

Objective: We sought to investigate how priming the tube between air versus air mixed with saline ex vivo influenced suction force. We examined how priming the tube influenced peak suction force and time to achieve peak suction force between both modalities. Methods: Using a Dwyer Instruments (Dwyer Instruments Inc., Michigan City, IN, USA), INC Digitial Pressure Gauge, we were able to connect a .072 inch aspiration catheter to a rotating hemostatic valve and to aspiration tubing. We recorded suction force measured in negative inches of Mercury (inHg) over 10 iterations between having the aspiration tube primed with air alone versus air mixed with saline. A test was used to compare results between both modalities. Results: Priming the tube with air alone compared to air mixed with saline was found to have an increased average max suction force (-28.60 versus -28.20 in HG, p<0.01). We also identified a logarithmic curve of suction force across time in which time to maximal suction force was more prompt with air compared with air mixed with saline (13.8 seconds versus 21.60 seconds, p<0.01). Conclusions: Priming the tube with air compared to air mixed with saline suggests that not only is increased maximal suction force achieved, but also the time required to achieve maximal suction force is less. This data suggests against priming the aspiration tubing with saline and suggests that the first pass aspiration primed with air may have the greatest suction force.

• 한국유체기계학회 논문집
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• 제14권4호
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• pp.19-24
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• 2011

An experimental study was conducted to examine the effectiveness of a suction-blowing fan that could not only remove polluted air by suction but also create the air-curtain by blowing. In order to create the air-curtain, rotors were installed on the surface of the shroud. These blows fresh air into the polluted region. The fresh air is spouted backward 45o on the basis of the axial direction using a double-ducted bellmouth. In the same suction operating condition, the suction region was extended by increasing the blowing velocity. However, the increasing rate of suction region was reduced when the blowing velocity was increased steadily. Thus, an efficient blowing velocity should be determined depending on the suction operating condition. In addition, the blowing requires additional input power. In a fixed suction operating condition, the input power was linearly increased in proportion to the blowing flowrate. When the suction-blowing fan was operated in the same input power as the suction fan, the suction region was increased more than 30% based on the 0.6m/sec velocity.

• 반도체디스플레이기술학회지
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• 제19권4호
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• pp.51-58
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• 2020

Many types of optical plastic films are essential in optoelectronics display unit fabrication and it is important to develop high precision laser cutting methods of optical films with extremely low level of film surface contamination by fume particles. This study investigates the effects of suction and blowing air motions with air flow misalignment in removing fume particles from laser cut line by employing random particle trajectory simulation and probabilistic particle generation model. The computational results show fume particle dispersion behaviors on optical film under suction and blowing air flow conditions. It is found that suction air flow motion is more advantageous to blowing air motion in reducing film surface contamination outside designated target margin from laser cut line. While air flow misalignment adversely affects particle dispersion in blowing air flows, its effects become much more complicated in suction air flows by showing different particle dispersion patterns around laser cut line. It is required to have more careful air flow alignment in fume particle removal under suction air flow conditions.

• 동력기계공학회지
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• 제21권2호
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• pp.89-94
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• 2017

Pneumatic systems are widely applied in various industry because it have a many advantage(low cost, high safety, etc.). Air compressors supply the working fluid to the pneumatic systems and consume a lot of electrical energy at the manufacturing site. The one of the suggested idea is to reduce the energy consumption by reducing the suction temperature of the air compressor and increasing the discharge flow rate. In this paper, the discharge flow rate and air power of the positive displacement type air compressor is simulated by changing the temperature of suction air and the relationship between the suction air temperature and the performance variation of the air compressor is analyzed. As a result, we know that as the suction temperature of air is lowered, the discharge mass flow-rate is increased, but the specific enthalpy is reduced rather than increased, which means that the power of the discharged air is not greatly increased even if lower the suction air temperature.

• Fibers and Polymers
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• 제6권3호
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• pp.250-258
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• 2005

The present paper is concerned with the influence of opening roller speed, drum speed difference and suction air pressure on properties of polyester and acrylic open-end friction spun yams. The results shows that the opening roller speed and the suction air pressure have considerable influence on the characteristics of polyester and acrylic open-end friction spun yams. In case of polyester yams the unevenness, imperfection and hairiness decreases and the yam tenacity increases with the increase in opening roller speed and suction air pressure. However for acrylic yams the unevenness and imperfections decreases and tenacity increases with the increase in opening roller speed and suction air pressure.

• Journal of Mechanical Science and Technology
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• 제14권12호
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• pp.1376-1385
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• 2000

This study investigates spray characteristics before and after wall impingingment of gasoline spray in suction air flow. For this study, a rectangular model intake port was made of acrylic glass, and suction air was generated by using the forced air blower contrariwise. The injector for this study was a pintle-type port gasoline injector in which an air-assist adaptor is installed to supply assisted air. A PDPA system was employed to simultaneously measure the size and velocity of droplets near the wall. Measured droplets are divided into "pre-impinging droplets"with positive normal velocity and "post-impinging droplets"were negative normal velocity for the suction flow. The velocities, size distributions and Sauter mean diameter(SMD) of pre-and post-impinging droplets for varions injection angles and air-assists are comparatively analyzed.

• 한국환경과학회지
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• 제3권2호
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• pp.177-184
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• 1994

An air suction skimmer was selected as a potable skimmer to be developed among the many reviewed skimmers because of its advantages such as simple structure, excellent transportability, and easy deployment. A prototype of the skimmer was fabricated. It was shown that the skimmer operated by a commercial vacuum cleaner has good performance. The maximum suction rate of water and the maximum suction head were 18$m^3$/hr and 2.7m, respectively.