• The KSFM Journal of Fluid Machinery
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• v.12 no.5
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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.

• Korean Journal of Adult Nursing
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• v.21 no.2
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• pp.141-154
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• 2009

Purpose: The purpose of this study was to compare the difference of change in oxygen saturation, vital signs and suction time taken for the suctioning during endotracheal suctioning performed with closed suction system and with opened suction system. Methods: Data were collected from 31 adult patients with ventilator treatment who were admitted to a university hospital in Seoul and the collection period was from July 1 to November 15, 2005. Oxygen saturation, heart rate, respiration rate and mean arterial pressure were collected immediately prior to the suctioning intervention, during and 1 and 5 minutes after the suctioning from opened suction system and closed suction system. Results: 1) The difference in oxygen saturation was statistically significant in recovery time for oxygen saturation to return to baseline values after suctioning was significantly rapid on closed suction system (p<.05). 2) The difference in heart rate, respiration rate and mean arterial pressure was statistically insignificant 3) The suction time was shorter in closed suction system. Conclusion: Closed suction system is more efficient, as compared with the open suction system in the ventilator treatment.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.11a
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• pp.110-121
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• 2001

The interest in suction piles by the oil industry was risen in the middle of 1980's. Recently, suction piles have been applied increasingly in offshore engineering due to its low cost, simplicity, efficiency, and reliability. Suction piles have normally been used as anchors of floating structures and foundations of marine structures in deep-water locations. Suction piles have several technical advantages over conventional piles and anchors; fast and easy installation at any depth of water, extremely large resistance due to its huge size, and easy retrieval by applying a positive suction pressure inside the pile, etc. Daewoo E&C Co., Ltd. has conducted a series of field suction pile installation and loading tests inside the Okpo harbor located in Geojedo and the Onsan harbor in Ulsan, Korea, during the summer of 2001, which may provide additional validation of the analytical solutions previously developed by the US Naval Facilities Engineering Service Center. This is a brief description of the general mechanisms of suction pile installation and loading capacity based on the study conducted by the US Navy and Daewoo E&C Co., Ltd.

• Proceedings of the KSME Conference
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• 2004.11a
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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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.12 s.243
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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.

• Geomechanics and Engineering
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• v.22 no.3
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• pp.237-244
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• 2020

To achieve a wide suction range, the low suction was imposed on compacted silt specimens by the axis translation technique and the high suction was imposed by the vapor equilibrium technique with saturated salt solutions. Firstly, the results of soil water retention tests on compacted silt show that the soil water retention curves in terms of gravimetric water content versus suction relation are independent of the dry density or void ratio in a high suction range. Therefore, triaxial tests on compacted silt with constant water content at high suctions can be considered as that with constant suction. Secondly, the results of triaxial shear tests on unsaturated compacted silt with the initial void ratio of about 0.75 show a strain-hardening behavior with a slightly shear contraction and then strain-softening behavior with an obviously dilation. As the imposed suction increases, the shear strength increases up to a peak value and then decreases when the suction is beyond a special value corresponding to the peak shear strength. The residual strength increases to fair value and those at high suctions are almost independent of imposed suctions. In addition, the contribution of suction to the strength of compacted silt would not diminish even in a high suction range.

• Journal of Mechanical Science and Technology
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• v.18 no.9
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• pp.1648-1660
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• 2004

The suction nozzle of a vacuum cleaner was modified to enhance the power performance and to reduce the airflow-induced acoustic noise. The suction power efficiencies of the vacuum cleaner were measured for various nozzles; (1) original nozzle, (2) original nozzle with modified trench height, (3) original nozzle with modified connecting chamber, and (4) a combination of (2) and (3). In addition, the suction pressure and sound pressure level around the suction nozzle were measured to validate the reduction of acoustic noise. The power efficiency and mean suction pressure increased when the trench height of the suction nozzle was increased. This was attributed to the suppression of the flow separation in the suction channel. Modification of the connecting chamber in the original nozzle, which had an abrupt contraction from a rectangular chamber into a circular pipe, into a smooth converging contraction substantially improved the suction flow into the connecting pipe. When both modifications were applied simultaneously, the resulting suction nozzle was more effective from the viewpoints of aerodynamic power increase and sound pressure level reduction.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.23 no.1
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• pp.25-33
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• 2016

Purpose: This study aimed to survey caregivers of patients with Neuromuscular Rare and Incurable Disease (NRID) using invasive home mechanical ventilator (HMV), in order to compare the incident rate of pneumonia by tracheal suction procedures used. Method: Participants were 99 family caregivers of NRID patients using HMV. Participants were given a questionnaire consisting of 12 demographic items, 10 items about disease and HMV related characteristics, 11 items about tracheal suction procedures, and 2 items about the incidence of pneumonia. Data were analyzed using chi-square tests and t-tests. Results: The items that predicted the incidence of pneumonia were "change of irrigation saline every suction" (p=.047), "use of aseptic catheter every suction" (p=.004), and "instillation of normal saline before suction" (p=.027). In addition, these items were 47.4%, 51.4%, and 38.8% respectively. Conclusion: Family members caring for NRID patients with invasive HMV should be educated about tracheal suction, especially the necessity of changing irrigation saline after every suction, using the aseptic catheter for every suction, and instillation of normal saline before suction. Medical personnel such as home care nurses should periodically check tracheal suction procedures, and re-educate family caregivers when necessary.

• The KSFM Journal of Fluid Machinery
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• v.14 no.4
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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.

• The KSFM Journal of Fluid Machinery
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• v.9 no.5 s.38
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• pp.22-27
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• 2006

Sedimentation phenomenon of suspended solids occurs by the gravitational force. Pollution particles are separated from slowly flowing waste water in clarifier. Recently, the sludge suction collector is Preferred rather than the scraper type sludge collector due to the enhancement of the clarifier efficiency. The sludge suction collector is usually operated by the user's experiences without any scientific and/or technical consideration. To evaluate the performance of sludge suction collector, the three dimensional numerical simulation was conducted by the finite volume method. To analyze the performance, the velocity vectors and the suction flow rates of the orifices were investigated. The result showed that each suction flow rate through out the collector was equivalent in the sludge suction collector and the efficiency of suction collector was good to remove high concentrated sludge in clarifier.