• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.32-36
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• 2007

When the vacuum system for the process of $SiH_{4}$ gas used in the semiconductor and FPD field is partially vented from vacuum to atmospheric state, a fire often occurs due to auto-ignition of $SiH_{4}$ gas. In order to prevent the fire, the concentration of $SiH_{4}$ should be kept under LFL. This means that the higher capacity pump is needed to meet the process conditions as well as the condition that the concentration of $SiH_{4}$ should be kept under LFL. In this article, we conducted the injection of the dilution gas at the manifold between booster pump and dry pump compared with the typical method that the dilution gas was injected into inlet port of booster pump using computer simulation. According to the result, we can flow further more purge gas for safety without any change of the condition in the process chamber, which means that the higher capacity pump is not required for safety in some cases.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1157-1161
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• 2011

Parametric study has been conducted to calculate the capacity of vacuum pump system that will be used to maintain the pressure of the tube system under atmosphere level. Recently many railroad researchers pay attention to the tube train system as one of the super high speed transportation system. To achieve the ultra super high speed, the inside of tube system should be maintained the low pressure level. In the low pressure environment, it is well known that air resistance of train is drastically decreased. Vacuum pump system will be used to make the low pressure level of tube system, exhaust the leakage air and supplement additional vacuum pumping. Qualitative and quantitative study has been conducted to review the effects of major parameters concerned with the capacity of vacuum pump system. As a results of these studies, we get the lump capacity of vacuum pump for various parameters. These results can be used to analyse the effects of the reduction of air resistance.

• Progress in Superconductivity and Cryogenics
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• v.15 no.4
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• pp.53-58
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• 2013

KSTAR in-vessel cryo-pump has been installed in the vacuum vessel top and bottom side with up-down symmetry for the better plasma density control in the D-shape H-mode. The cryogenic helium lines of the in-vessel cryo-pump are located at the vertical positions from the vacuum vessel torus center 2,000 mm. The inductive electrical potential has been optimized to reduce risk of electrical breakdown during plasma disruption. In-vessel cryo-pump consists of three parts of coaxial circular shape components; cryo-panel, thermal shield and particle shield. The cryo-panel is cooled down to below 4.5 K. The cryo-panel and thermal shields were made by Inconel 625 tube for higher mechanical strength. The thermal shields and their cooling tubes were annealed in air environment to improve the thermal radiation emissivity on the surface. Surface of cryo-panel was electro-polished to minimize the thermal radiation heat load. The in-vessel cryo-pump was pre-assembled on a test bed in 180 degree segment base. The leak test was carried out after the thermal shock between room temperature to $LN_2$ one before installing them into vacuum vessel. Two segments were welded together in the vacuum vessel and final leak test was performed after the thermal shock. Commissioning of the in-vessel cryo-pump was carried out using a temporary liquid helium supply system.

• Applied Science and Convergence Technology
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• v.24 no.1
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• pp.9-15
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• 2015

The practical pumping speed of a dry pump is considerably lower than the intrinsic speed because of back-streaming through finite gaps of the rotor assembly. The maximum compression ratio and the ultimate pressure of the pump are also directly influenced by the back-streaming rate. Therefore, information on the gap conductance, which determines the back-streaming characteristics of the rotor assembly, is the most important key for estimating the pumping performance of a dry pump. In this paper, the feasibility of calculating analytically the pumping performance of a multi-stage Roots pump, one of the most popular types of dry pumps, by quantifying the gap conductance in a rational way, is discussed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.618-619
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• 2010

Thermal transpiration device(Knudsen pump) having no moving parts can self-pump the gaseous propellant by temperature gradient only (cold to hot). We designed, fabricated the Knudsen pump and analyzed pressure gradient efficiency of membrane according to Knudsen number under vacuum condition. In this paper, we measured presented pumping efficiency of Knudsen pump according to Hanji membrane.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.321-322
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• 2009

• Proceedings of the Korean Vacuum Society Conference
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• 1995.06a
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• pp.61-62
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• 1995

Seiko Seiki develops and munufactures magnetic Bearing type Turbomolecular Pumps (MB-TMP), Seiko shipped 14,000 MB-TMPs and holds the world's largest share in the MB-TMP field. It developed a new 300 (l/s) class turbomolecular pump.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.145-152
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• 2001

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.667-668
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• 2010

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.43-43
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• 2000

당사는 (주)포스콘 진공 사업 부분이 분사하여 1999년 1월 진공 장비 및 제어계측 분야 독립 법인체를 설립하였으며 당사의 주력 제품은 초고진공용 Ion pump 및 controller로서 국산화 개발하여 생산 판매하고 있다. Ion pump 와 controller는 10-4 ~ 10-10 Torr 범위의 초고진공으로 진공 시스템을 배기할 수 있는 장비로서 무소음, 무진동, 저전력의 특성을 가진 초정밀, 초청정 진공 실험에 없어서는 안 될 펌프이다. 현재 당사는 과학기술부의 특정연구개발 과제를 극고진공(XHV)용 Ion Pump를 개발하고 있는 중이다.