• Tribology and Lubricants
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• v.16 no.6
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• pp.440-447
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• 2000

It's a tendency to strengthen related international laws as the importance on marine oil pollution recently becomes the issue. According to the regulation of IMO, oil discharge from ships is allowed under 15 ppm only and oil filtering equipment is essential. However, for large ships using heavy fuel oil of over S.G 0.98 and viscosity 380 cSt and system oil, it has been in difficulty to process with existing filtering type of oily water separator. Oily water pre-separator of laminated plate type which is one of gravity type separator has very simple structure and it also makes easier to maintain and repair. In another words, it fits well to process large amount of rich oil with high specific gravity. In this paper, oily water pre-separator of laminated plate type has been studied. The function of emulsified oil and 4 different types of oil have been analyzed and each character has been investigated and proved by experiments. As the result of it, the efficiency of separating oil water has been advanced by 10% in case equipped with pre-separator. In addition, the higher temperature is and the more laminated plate has, it turns out to be getting more effect.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.2
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• pp.365-374
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• 2001

Its a tendency to strengthen related international was as the importance on marine oil pollution recently becomes the issue. According to the regulation of IMO, oil discharge from ships is allowed under 15PPM only and oil filtering equipment is essential. Oily water separator of laminated plate type which is one of gravity type separator can be use as assistant equipment for the oil filtering system to meet the present IMO standard, because it fits well to process large amount of rich oil with high specific gravity. The purpose of this paper is to investigate an efficiency of oil/water separation with the characteristics of laminated plate arrangement. The analyse of oil contents for oil-water mixture were carried out in order to find an efficiency of oil/water separation and an experimental study was simultaneously carried out to investigate internal flow characteristics of separator by visualization method and PIV(Particle Image Velocimetry) measurement at three spaces of plates for 5, 10 and 15 mm with variation of inlet flow rates of $0.25m^3$/h and $0.5m^3$/h. The experimental results showed that the space of the plates acts a significant role in the separating process.

• Journal of Power System Engineering
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• v.11 no.2
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• pp.20-25
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• 2007

The performance of air-to-air heat exchanger has been investigated with rotating porous plates newly developed in this study. With an equal interval of 18 mm, the rotating porous plates are installed inside the heat exchanger where the hot and cold airs enter at opposite ends. When flowing in opposite directions by the separating plate installed in the center of the rotating porous plates, the airs give and receive the heat each other. Dry bulb temperature is set by adjusting heat supply at heater. In order to measure the temperature distribution of the hot air side inside heat exchanger, the thermocouples are inserted between the plates. The first location of thermocouple is 10mm downstream from the inlet of heat exchanger, and succeeding ten locations are aligned at an equal interval of 18mm. From the experiment of air-to-air heat exchanger with the rotating porous plates, the heat transfer rate increased as both air flow rate and RPM of the rotating porous plate increased. It was found that the overall heat transfer coefficient increased with the increase in RPM of porous plate at the conditions of the same air flow rate.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.1
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• pp.139-148
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• 2015

In this paper, a new algorithm is proposed for detecting the product number of each thick plate and extracting each character of the product number from a image which contains several thick plates. In general, a image of thick plates contains several steal plates. To obtain the product number from the image, we first need to separate each plate. To do so, we use the line edges of thick plates and a clustering algorithm. After separating each plate, background parts are eliminated from the image of each plate. Background parts of an individual thick plate image consist of the dark part of steel and the white part of paint which is used for printing the product number. We propose a two-tiered method where dark background parts are first eliminated and then white parts are eliminated. Finally, each character is extracted from the product number image using the characteristics of product number. The results of the experiments on the various steal plates images emphasize that the proposed algorithm detects each thick plate and extracts the product number from a image effectively.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.404-406
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• 2002

We have investigated the contribution of the scattered x rays to the signal imaging in the radiographs acquired with anti-scatter grids of several grid ratios by separating the line spread functions (LSFs) derived from the signal edge image into the primary and the scatter components. By using a 1.0-mm lead plate in the scattering material, the blurred signal edge images were acquired by use of an imaging plate at a tube voltage of 80 kV with the anti-scatter grids of grid ratios for 5:1, 6:1, 8:1, 10:1 and 12:1. The edge profiles of the signal images were scanned and those in relative exposure were differentiated to obtain the LSFs. To investigate the contribution of the scattered x rays to the signal imaging, we proposed a method for separating the LSFs derived from the signal images into the primary and the scatter components, where the scatter component was approximated with exponential function. Our basic approach is to separate the area of the LSFs by ratios of the scattered x-ray exposure to the primary x-ray exposure, which were obtained for the grid ratios by use of a lead disk method. The LSFs and the two components were Fourier transformed to obtain the modulation transfer functions (MTFs) and their two components. As the result, we found that, by using the anti-scatter grids, the scattered x rays were reduced, but the shape of the LSFs of the scatter component hardly changed. The contributions of the scatter component to the MTFs were not negligible (more than 10 %) for spatial frequencies lower than about 1.0 mm$\^$-l/ and that was greater as the grid ratio decreasing. On the other hand, for higher frequencies, the primary component was dominant compared with the scatter component.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.103-106
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• 2009

Fracture characteristics of plate shape using shock tube for glass filled ceramics was carried out. Glass filled ceramics have been considered as a promising candidate material for the dome port cover of air breathing engine. This part of the air breathing engine has an important role separating solid and liquid fuel, and needs the frangible characteristics that the fracture of a part should not affect the internal components of combustion. The objectives of this study are to evaluate the fracture pressures for various thicknesses and diameters of shock impact area. Also fracture phenomena of separated membrane using a shock tube are observed. The experimental apparatus of shock tube consists of a driver, a driven section and a dump tank. The used material is glass filled ceramic made from Corning company. Specimens are used 3, 4.5 and 6mm thickness. Also diameters of shock wave area are chosen 70, 60 and 50 mm. It is expected that the results obtained from this study can be used in the basic data for the dome port cover design of an air breathing engine.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.18-23
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• 2005

The experimental investigation was carried out to evaluate the performance of air-to-air heat exchanger with rotating porous plates newly developed in this study. The rotating porous plates are mounted with an equal interval of 18 mm inside the heat exchanger where the hot and cold airs enter at opposite ends. When flowing in opposite directions by the separating plate installed in the center of the rotating porous plates, the airs give and receive the heat each other. The material of the porous plate is cooper and its thickness is 1.0 mm. Air flow rate is varied from 10 to 120 m3/h. From the experiment of air-to-air heat exchanger with the rotating porous plates, the heat exchange performance increased with the increase in RPM of the porous rotating discs at the conditions of the same air flow rate. The sensible heat exchange efficiency was maximum 60 to 70 percent, and enthalpy exchange efficiency 50 to 60 percent.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.99-103
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• 2019

Recently, as the high-precision machinery industry has developed rapidly, peripheral equipment has been developed to improve machining efficiency. Peripheral equipment for machining includes cooling units, housings, oil separators, and much more. Oil, such as cleaning and cutting fluids, is used for machining. When waste oil is reused, the contamination of the workpieces and reduction in machining accuracy are generated by the waste oil, including sludge. Therefore, the development of an oil separator is necessary for efficiently separating oil, water, and sludge. The purpose of this study is to analyze the oil separation efficiency and flow characteristics of a high-speed centrifugal separator according to the rotation velocity and diffusion plate. The oil separation efficiency and flow characteristics were analyzed using hydrodynamic theory and computational fluid dynamics (CFD). The results of this study will be used as basic data for the development of a high-speed centrifugal separator.

• Journal of Biosystems Engineering
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• v.9 no.2
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• pp.48-57
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• 1984

To analyze the grain transport velocity, which is valuable for optimizing the separation losses, an oscillating appratus for sieve was designed. The grain transport velocity was measured in each combination of three amplitude levels, three rpm levels and four projection angle levels. To analyze the grain transport velocity theortically, two computer programs were developed. And the results from experiment and theoretical analysis were compared. 1. The grain transport velocity was increased with the projection angle of oscillating sieve. Especially when the projection angle is higher than $45^{\circ}$ the grain transport velocity on the flat-plate was not increased but on the racked surface was increased persistently. 2. The grain transport velocity was increased linearly with the frequency of oscillating motion. The speed of driving link must be higher than 350 rpm at 24mm amplitude, 250 rpm at 36 mm amplitude to transport the grain efficiently. 3. The grain transport velocity was increased with the amplitude of oscillating motion. But if the amplitude was smaller than interval of racks, the grain on the racked surface was not transported, even though the projection angle or the speed of revolutionary link was increased. 4. The transport characteristics of a grain varied with the amplitude and projection angle. Especially in the range of 1.5 < K < 2.3 at $45^{\circ}$ projection angle the transportation of grain was successful and the grain motion consisted of sliding movement (forward, backward) and jumping movement, which is considered recommendable for separating process of a combine sieve. 5. The results from theoretical analysis were approximately in accord with that from experiment.

• Steel and Composite Structures
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• v.22 no.6
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• pp.1417-1443
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• 2016

Cellular and castellated steel beams are used to obtain higher stiffness and bending capacity using the same weight of steel. In addition, the beam openings may be used as a pass for different mechanical fixtures such as ducts and pipes. The aim of this study is to investigate the effect of different parameters on both elastic and inelastic critical buckling stresses of steel web plates with openings. These parameters are plate aspect ratio; opening shape (circular or rectangular); end distance to the first opening; opening spacing; opening size; plate slenderness ratio; steel grade; and initial web imperfection. The web/flange interaction has been simplified by web edge restraints representing simply supported boundary conditions. A numerical parametric study has been performed through linear and nonlinear finite element (FE) models, where the FE results have been verified against both experimental and numerical results in the literature. The web plates are subject to in-plane linearly varying compression with different loading patterns, ranging from uniform compression to pure bending. A buckling stress modification factor (${\beta}$-factor) has been introduced as a ratio of buckling stress of web plate with openings to buckling stress of the corresponding solid web plate. The variation of ${\beta}$-factor against the aforementioned parameters has been reported. Furthermore, the critical plate slenderness ratio separating elastic buckling and yielding has been identified and discussed for two steel grades of DIN-17100, namely: ST-37/2 and ST-52/3. The FE results revealed that the minimum ${\beta}$-factor is 0.9 for web plates under uniform compression and 0.7 for those under both compression and tension.