• Journal of Power System Engineering
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• v.14 no.4
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• pp.23-28
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• 2010

Of the roughly four million known substances, about 60,000 are processed and sold ; many of these must be dried. Many materials are processed in the liquid state - ideal for mixing and reacting - but most products are needed or wanted as dry, or relatively dry, solids. Usually operation is just below atmospheric pressure, as with direct dryers, but some are built for vacuum operation with pressures as low as 26.66kPa abs.. In spite of the global-class aquiculture agriculture and fisheries technology of our country, the processing technologies are lags behind the other nations relatively. These problems are considered to be caused directly by the lack of drying technologies. This paper is concerned to the experimental results of drying heat transfer characteristics for the green energy type vacuum dryer for the high quality agriculture and fisheries production.

• Current Industrial and Technological Trends in Aerospace
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• v.8 no.1
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• pp.55-61
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• 2010

Thermal vacuum test should be carried out to verify the performance of the S/C on the ground under the simulated space environment. KARI already completed the construction of a Large Thermal Vacuum Chamber(LTVC) with 8 m of diameter and 10 m of length dimension. LTVC is for the purpose of performing the orbital environment test for large Space Craft(S/C). Inside LTVC, S/C is much smaller than LTVC. For the function test of S/C during the thermal vacuum test, the S/C has to be connected to Electrical Ground Support Equipment(EGSE) which includes several cable and RF wave guide inside LTVC. Also, MLI should be installed on S/C before the test. But it is very difficult to access the S/C inside big LTVC. To solve the accessibility to the S/C inside LTVC, KARI designed an access fixture. This fixture provides easy access to the any S/C thus can help safe installation and saving time for the related work inside LTVC. This paper describes whole process for the design of the access fixture.

• Journal of the Korean Vacuum Society
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• v.19 no.3
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• pp.161-168
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• 2010

The ISO standard specifies the diameter of the gas introducing tube to be definitely 1/10 of the chamber inner diameter of the standard test dome which is used for evaluating the performance of vacuum pumps. Because the inner diameter of the test chamber should not be less than the intake diameter of the vacuum pump, the tube diameter would be even 100 mm if fitting to a very large vacuum pump. Though such a thick tube can be accommodated in a large test dome, it is worthful to investigate whether a thicker tube is helpful or adverse for making more accurate measurements. In this paper it is discussed if there is an optimum tube diameter by comparing the isotropicity of particles emanating from the tube and that of particles entering the orifice.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.12
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• pp.971-977
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• 2016

Recently, the problem of the accumulation of fine sludge from the cutting oil generated during machining processes has become a major threat to the environment. The fine sludge has adverse affects on the human body and the environment, and significantly contributes to marine pollution. However, a microfiltration technique that can process the sludge still needs to be studied and developed on a global scale. Therefore, it is necessary to develop eco-friendly equipment such as an ECO vacuum filter system and eco-friendly technologies for processing cutting oil. In this study, a structural analysis was carried out using a finite element method (FEM). Improved models of the suction chamber for the ECO vacuum filter system were proposed based on the analysis of the displacement and stress of the system. The model with the best result was then optimized using the commercial software, ANSYS. It was confirmed that, in the optimized model, displacement and stress were reduced in comparison with the initial model. Finally, the structural stability of the optimized model was verified through analysis.

• Journal of the Korean Vacuum Society
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• v.1 no.2
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• pp.237-243
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• 1992

Two gaskets of Al 2024-T4 and annealed al 2024-T4 were made. We had acquired 2 $\times$ 10-12torr in a chamber using them. Microstructures, hardness and stress concentration of the gaskets were examined before and after baking. Knife edge damages such as decrease of edge height(H) and increase of edge angle() were found on knife edges when the Al 2024-T4 gasket was used. But no damage was found with the annealed Al 2024 gasket.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1078-1083
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• 2000

A high speed rotor balancing machine was developed, which is capable of balancing a flexible rotor in high speed. The machine is largely consisted of vacuum chamber, oil supply system and vacuum pump system. And, in order to investigate performances of the machine, various tests were carried. After high speed rotor balancing of gas turbine engine rotor using influence coefficient method, the flexible engine rotor passed smoothly through its critical speed.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.147-148
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• 2000

Sealing of two glass plates composing of FED panel was done in a vacuum chamber. Several factors related with a heating process of a frit glass were investigated, including comparisons with a conventional method.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.416-421
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• 2011

In this paper, the relationship of chamber contamination and the intensity change of specific wavelength was investigated. "diff_CO" formula was introduced to rule out background noise caused by external conditions and to detect when the polymer is removed from the chamber. As RF time increased, diff_CO trend showed the decrease of the maximum peak and increased number of small intensity peaks. From the diff_CO change, it was possible to determine when the chamber needs to be cleaned without opening the chamber.

• Resources Recycling
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• v.9 no.4
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• pp.28-36
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• 2000

This study describes to analyze the characteristics for separation and recovery of both the dried particles and the purified solvent from the waste solvent through the vaporization process by the continuous and instantaneous vacuum drying system. The vacuum drying system for the waste solvents recovery consists of a feeding pump, a double pipe heat exchanger, a vacuum spray chamber, and a condenser. The vacuum drying system heats the waste solvent to the vapor in the double pipe heat exchanger and the expanded vapor is sprayed at the end of the tube. The vaporized solvent in the condenser are recovered. The particles in the waste solvent are separated and dried from the vapor in the vacuum spray chamber. Performance evaluation of the vacuum drying system was conducted using the mixture of the dried pigment particles and benzene or alkylbenzene as test samples. For the mixture of 10 wt% pigment particles an 90% benzene, the recovery efficiency of benzene was 88% with the purity of 99% and the recovery efficiency of dried particles was 94% with the moisture of 1.1 wt%. The size of pigment particles was decreased from $6.5\mu\textrm{m}$ to $5.6\mu\textrm{m}$ in diameter due to high speed spraying and dispersion in the vacuum drying system during drying process. Therefore, the vacuum drying system showed to be an effective method for separating particles and solvent in the waste solvent.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.432-437
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• 1999

We have fabricated an in situ ellipsometer operating at He-Ne wavelength. It can be applied to the real-time, in-situ tracking of the ellisometric change which occurs during various sample treatments. As a rotating analyzer type, all optical elements and related parts are designed to share a common hollow-axis configuration, and hence the ellipsometer is compact in shape and simple in design. It is mountable on the spare ports of vacuum chamber with ease. Using this ellipsometer, we observed the effective density variation of previously grown $TiO_2$ thin films by using electron beam evaporation. The packing density of the as-grown film was 82%. When exposed to atomsphere, the micro-void of the film was filled with water vapor. This water-filled $TiO_2$ thin film was subject to heating/cooling cycles in vacuum and the ellipsometric variation versus temperature and cycling number was measured in real time using this in situ He-Ne ellipsometer.