• Title/Summary/Keyword: 기화압

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Comparison of Cold Vapor Atomic Absorption Spectrophotometry Analysis and EPA Method 101A for Measurement of Mercury in the Flue Gas (배출가스중 수은 측정을 위한 환원기화 원자흡광광도법과 EPA Method 101A의 비교 연구)

  • 김경희;최양일;박일수;홍지형;차준석;석광설;김대곤
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.92-93
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    • 1999
  • 수은은 상온에서 액체상태로 존재하는 유일한 금속으로서, 증기압이 매우 높기 때문에 가장 쉽게 휘발될 수 있는 중금속이다. 다른 중금속들은 거의 입자 상태로 변환되기 때문에 전기 집진기 등과 같은 일반적인 입자 제어시설에서 98%이상이 제거되지만, 증기압이 매우 높은 수은은 다단계 습식 스크러버, 활성탄을 사용하는 전기집진기/습식 스크러버가 결합된 특정한 방지시설에 없는 한 거의 대부분이 그대로 배출된다.(중략)

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An Experimental Study on Pressure-resistant Performance of a Re-fillable LPG Cylinder (LPG 재충전 소형 용기의 내압성능에 관한 실험적 연구)

  • Yim, Sang-Sik;Jang, Kap-Man;Lee, Jin-Han
    • Journal of the Korean Institute of Gas
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    • v.18 no.2
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    • pp.16-20
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    • 2014
  • In this paper, the performance of pressure-resistance is validated by experiment on LPG re-fillable cylinder which has increased demands for spreading of camp culture. Propane has increased suppliable requirements as fuel because of easily vaporizing effect of low boiling point. However, propane can be occurring safety problems inevitably by high vapor pressure. So, the priority is that safe cylinder should furnish in order to be circulated as safe fuel. LPG re-fillable cylinder for high pressure is tried to furnish internationally, that is restricted by safe issues. For these reasons, the pressurization and rupture are performed by using pressurizing device that is operated by hydraulic system. Also, this paper will offer rupturable characteristics comparing with vapor pressure of propane. This paper is expected as basis research for developing re-fillable cylinder and using standard for supplying them.

An Investigation into the Effect of Each Parameter of S/A on the Damping Force Using Dynamic Behaviour Analysis P/G (충격 흡수기의 동적거동 해석 프로그램을 이용한 각 파라미터가 댐핑력에 미치는 영향 조사)

  • 박재우;신상윤;주동우;이시복
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.371-376
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    • 1996
  • The damping force of shock absorber in an automobile is determined by the components which construct the S/A. In this study we investigate the individual effect of these components on damping force. In addition, opening of important valve doling compression and tension cycle due to up-down reciprocation movement is also researched. Thus we are to strictly control the properties and tolerance of components having important effects on tile damping force and to produce S/A of better quality.

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An Investigation into the Effect of Each Parameter on the Damping Forces Using Dynamic Behaviour Analysis P/G of S/A (충격 흡수기의 동적거동 해석 프로그램을 이용한 각 파라미터가 감쇠력에 미치는 영향 조사)

  • Park, J.W.;Shin, S.Y.;Lee, S.B.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.10
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    • pp.44-49
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    • 1997
  • The damping force is determined by four valves and the components which consist of the shock absorber for vehicle. In this study it is investigated the individual effects of four valves and these components on damping forces using dynamic behaviour analysis program of the shock absorber. In addition, opening of main valves are researched during compression and tension cycle due to up- down reciprocation movement of piston. We are to strictly control the properties and tolerance of componenets having important effects on the damping force. Thus we are intended to produce shock absorber of better quality.

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Vaporization of Hydrocarbon Fuel Droplet in Supercritical Environments (아임계 및 초임계 탄화수소 연료 액적의 기화 특성 연구)

  • Lee,Gyeong-Jae;Lee,Bong-Su;Kim,Jong-Hyeon;Gu,Ja-Ye
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.7
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    • pp.85-93
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    • 2003
  • Droplet vaporization at various ambient pressures is studied numerically by formulating one dimensional evaporation model in the mixture of hydrocarbon fuel and air. The ambient pressure ranged from atmospheric conditions to the supercritical conditions. The modified Soave-Redlich-Kwong state equation is used to account for the real gas effects in the high pressure condition. Non-ideal thermodynamic and transport properties at near critical and supercritical conditions are considered. Some computational results are compared with Sato's experimental data for the validation of calculations. The comparison between predictions and experiments showed quite a good agreement. The droplet lifetime increases with increasing pressure at temperature lower than the critical temperature, however, it decreases with increasing pressure at temperature higher than the critical temperature. The solubility of nitrogen can not be neglected in the high pressure and it becomes higher as the temperature and the pressure go up.

Experimental and Numerical Study on the Dynamic Fracture Processes of PMMA Block by NRC Vapor Pressure Fracture Agent (NRC 증기압 암석 파쇄제에 의한 PMMA 블록의 동적 파괴 과정에 관한 실험 및 수치해석적 연구)

  • Gyeongjo Min
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.1
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    • pp.91-103
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    • 2023
  • This study aims to investigate the dynamic fracture characteristics of rocks and rock-like materials subjected to the Nonex Rock Cracker (NRC), a vapor pressure crushing agent that produces vapor pressure by instantaneously vaporizing a liquid mixture crystallized through the thermite reaction. Furthermore, the study seeks to develop an analytical technique for predicting the fracture pattern. A dynamic fracture test was performed on a PMMA block, an artificial brittle material, using the NRC. High-speed cameras and dynamic pressure gauges were employed to capture the moment of vapor pressure generation and measure the vapor pressure-time history, respectively. The 2-dimensional Dynamic Fracture Process Analysis (2D DFPA) was used to simulate the fracture process caused by the vapor pressure, with the applied pressure determined based on the vapor pressure-time history. The proposed analytical method was used to examine various fracture patterns with respect to granite material and high-performance explosives.

Evaluation on Spalling Properties of Ultra High Strength Concrete with Melting and Vaporization of Fiber (유기섬유의 용융 및 기화에 따른 초고강도 콘크리트의 폭렬 특성 평가)

  • Kim, Gyu-Yong;Choe, Gyeong-Cheol;Lee, Joo-Ha;Lee, Seung-Hoon;Lee, Tae-Gyu
    • Journal of the Korea Concrete Institute
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    • v.24 no.2
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    • pp.173-183
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    • 2012
  • Recently, experimental studies to prevent explosive spalling based on spalling mechanism and addition of Polypropylene fiber in high strength concrete (HSC) are performed actively. However, with respect to ultra high strength concrete (UHSC), its compact internal structure is more difficult release vapor pressure at rapid rising temperature compared to HSC. Therefore, in this study, an experiment was conducted to evaluate spalling properties of UHSC using ${\Box}$ $100mm{\times}100{\times}H200mm$ rectangular specimen according to ISO-834 standard fire curve. With respect melting point of fiber, three fiber types of Polyethylene, Polypropylene, and Nylon fibers with melting temperature of $110^{\circ}C$, $165^{\circ}C$, and $225^{\circ}C$, respectively, were considered. Mixed fiber of 0.15% and 0.25% of concrete volume was used to consider spalling properties based on water vapor pressure release. Then, TGDTA test on fiber and FEM analysis were performed. The results showed that it is difficult to prevent initial spalling without loss of fiber mass even if fiber melting temperature is low. Also, in preventing thermal spalling, fiber that melts to rapidly create porosity within 10 minutes of fire is more effective than that of low melting temperature property of fiber.

A Study on a Heat Transfer Characteristics of Direct Contact Heat Exchanger for Steam Condensation According to Various Cooling Water Flow and Internal Pressure(The Purpose of Combination with LNG Evaporator) (증기응축용 직접접촉식 열교환기의 냉각수 유량과 내부압 변화에 따른 열전달 특성연구(LNG 기화기와의 조합목적))

  • Lee, B.C.;Han, S.T.;Kim, C.B.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.3 no.3
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    • pp.153-160
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    • 1991
  • Heat transfer characteristics of a direct contact heat exchanger utilizing sieve trays and spray nozzles for steam condensation for the purpose of combining with a LNG evaporator have been investigated with various cooling water flow rates and different vacuum pressures within the heat exchanger for the purpose of steam condensation. Temperature profiles and the volumetric overall heat transfer coefficients in a direct contact heat exchanger have been obtained for comparisons. The results show that the temperature differences between cooling water and steam along the direct contact heat exchanger height are rapidly decreasing and the volumetric overall heat transfer coefficients of the exchanger improves greatly as the inside vacuum pressure increases. The values of the overall heat transfer coefficients at P=-680mmHg have been increased significantly compared with at atmospheric pressure. At given pressure conditions, it is found that the values of average volumetric overall heat transfer coefficients for the sieve tray are found to be approximately 10% higher than those of the spray nozzle.

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Evaluation of Granite Melting Technique for Deep Borehole Sealing (심부시추공 밀봉을 위한 화강암 용융거동 평가)

  • Lee, Minsoo;Lee, Jongyoul;Ji, Sung-Hoon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.4
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    • pp.479-490
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    • 2018
  • The granite melting concept, which was suggested by Gibb's group for the closing of a deep borehole, was experimentally checked for KURT granite. The granite melting experiments were performed in two pressure conditions of atmospheric melting with certain inorganic additives and high pressure melting formed by water vaporization. The results of atmospheric tests showed that KURT granite started to melt at a lower temperature of $1,000^{\circ}C$ with NaOH addition and that needle shaped crystals were formed around partially melted crystals. In high pressure tests, vapor pressure was increased by adding water with maximum pressure of about 400 bars. KURT granite was partially melted at $1,000^{\circ}C$ when vapor pressure was low. However, it was not melted at vapor pressures higher than 200 bars. Therefore, it was determined that high pressure with a small amount of water vapor more effectively decreased the melting point of granite. Meanwhile, high temperature and high pressure vapor caused severe corrosion of the reactor wall.

Calculation of the amount of excess As charge for the GaAs single crystal growting with the horizontal Bridgman method of single temperature zone(1-T HB) (단일 온도대역 수평 Bridgman(1-T HB) 법에 의한 GaAs 단결정 성장시 As 원소의 초과 유입량 계산)

  • 오명환;주승기
    • Korean Journal of Crystallography
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    • v.7 no.1
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    • pp.64-72
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    • 1996
  • Calculation of the amount of excess arsenic charge has been carried out for the single crystal growth of GaAs with 1-T HB(single temperature zone horizontal Bridgman) method which has no low temperature arsenic zone. Based upon the investigation of the thermochemical properties of the Ga and As system, a general equation for the excess dimension of the ampoule and temperature gradient of the furnace. From this result, a theoretical background of the 1-T HB method has been constructed for the single crystal growth of GaAs.

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