• 제목/요약/키워드: Gas-Liquid

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Application of Preconditioning Method to Cavitating Flow Computation

  • Shin, Byeong-Rog
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1903-1908
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    • 2004
  • A preconditioned numerical method for gas-liquid two-phase flows is applied to solve cavitating flow. The present method employs a finite-difference dual time-stepping integration procedure and the MUSCLTVD scheme. A homogeneous equilibrium cavitation model is used. The present density-based numerical method permits simple treatment of the whole gas-liquid two-phase flow field, including wave propagation, large density changes and incompressible flow characteristics at low Mach number. Some internal flows such as convergent-divergent nozzles are computed using this method. Comparisons of predicted and experimental results are provided and discussed.

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First Derivative Spectrophotometric and Gas-Liquid Chromatographic Determination of Caffeine in Foods and Pharmaceuticals III. Simultaneous assay of caffeine and some antihistaminics

  • Abdel-Moety, Ezzat M.;El-Tarras, Mohamed F.;El-Zeany, Badr-Eldin A.;Kelani, Khadiga O.
    • Archives of Pharmacal Research
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    • 제13권3호
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    • pp.215-220
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    • 1990
  • Two different, derivative spectrophotometric and gas-liquid chromatographic, procedures for direct quantitation of caffeine and some commonly dispensed antihistaminics in bulk forms, in their laboratory prepared mmixtures and in dosage formulations, have been investigated. The limit, sensitivity reproducibility and accuracy of each method were studied for each individual drug substance and in some usual pharmaceutical formulations.

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Ralu-Pack 250YC를 충전한 충전탑에서 암모니아가스 제거에 관한 연구 (A study on Removal of $NH_3$ Gas in a Towar using a Ralu-Pack 250YC as a Packing Material)

  • 김석택
    • 한국환경과학회지
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    • 제9권5호
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    • pp.389-392
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    • 2000
  • In this study a packed tower was selected for the treatment apparatus of $NH_3$ gas produced in industry. Formerly latticework packing has been used in preventive facility of treatment of $NH_3$ gas. However recently metallic Ralu-Pack 250YC. structured packing is usually being used in petrochemical production plant. This study is for the application the packing to the $NH_3$ gas treatment in wet scrubbing process. In Air/water system hydraulic pressure drop dependent of specific liquid load and gas capacity factor was continuous and parallel from graph. The tower height can be determuined by the number of transfer unit and the height of transfer unit influenced on liquid distribution.

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고로하부 액체유동에 대한 수치해석 사례 - 냉간유동 (Numerical Simulation of the Liquid Flow in the Lower Part of the Blast Furnace - A Cold Flow Case)

  • 진홍종;최상민;정진경
    • 한국연소학회지
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    • 제13권2호
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    • pp.33-41
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    • 2008
  • The high permeability of the gas in the molten iron of the dripping zone of the blast furnace is a major factor in achieving the stable operation of a furnace with high productivity. Basic studies of the liquid flow behavior in a packed bed are necessary to grasp the effect of various operational changes on conditions in the dropping zone. Molten iron and slag together playa critical role in the lower zone, transporting mass and energy, while impairing and redistributing the gas flow. In turn, molten iron and slag undergo physical and chemical changes, and are redistributed radially as they descend to the hearth. In this research, mathematical formulations are derived for the gas and the liquid. The solid phase is fixed with constant porosity. The information for the molten iron and slag includes the hold-up, velocity, pressure, and information related to the areas of interaction between the gas and the liquid, and the solid and the liquid. Predictable results include the velocity, pressure and temperature distribution. Additional parameters include the packed particle size and the air blast rate.

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금망임펠러를 이용한 교반조에서의 기-액 물질이동 (Mass Transfer of Gas-Liquid in Agitated Vessel Using Wire Gauge Impeller)

  • 이영세
    • 한국산업융합학회 논문집
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    • 제11권1호
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    • pp.19-26
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    • 2008
  • The gas-liquid mass transfer volumetric coefficients in gas-liquid agitated vessels with wire gauge impellers were measured to be compared with those in vessels with disk turbine and paddle impellers. Also mass transfer volumetric coefficients for disk turbine, paddle impeller and wire gauge impeller in cylindrical agitated vessel was measured over a wide range of Reynolds number from turbulent flow to transition regions. The effect of geometries on $k_La$ is clarified experimentally. Mass transfer volumetric coefficients $k_La$ depends only on the power consumption ($P_{gv}+P_{av}$) per unit volume.

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기체크로마토그래피/질량분석기에 의한 저질 및 토양시료 중 벤조페논의 분석법 연구 (Analysis of Benzophenone in Sediment and Soil by Gas Chromatography/Mass Spectrometry)

  • 권오승;김은영;류재천
    • Environmental Analysis Health and Toxicology
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    • 제16권3호
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    • pp.121-126
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    • 2001
  • Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (%) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6% and 40.0∼83.0%, respectively. Recovery of BP by liquid-liquid extraction was 51∼59% in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.

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액체로켓엔진 가스발생기 개발에서의 연소불안정 경험 사례 (Experience Cases of Combustion Instability in Development of Gas Generator for Liquid Rocket Engine)

  • 김문기;임병직;김성구;김종규;최환석
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.61-64
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    • 2017
  • 한국형발사체에 적용되는 액체로켓엔진은 가스발생기 개방형 엔진 사이클을 채택한다. 가스발생기에서 연소 불안정이 발생하면 연소 성능이 변하고 진동, 소음 등의 문제점을 야기하거나 하드웨어의 손상을 초래할 수 있다. 본 연구에서는 액체로켓엔진의 가스발생기를 개발하면서 나타난 연소불안정 경험 사례를 소개하고자 한다.

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Semiempirical model for wet scrubbing of bubble rising in liquid pool of sodium-cooled fast reactor

  • Pradeep, Arjun;Sharma, Anil Kumar
    • Nuclear Engineering and Technology
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    • 제50권6호
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    • pp.849-853
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    • 2018
  • Mechanistic calculations for wet scrubbing of aerosol/vapor from gas bubble rising in liquid pool are essential to safety of sodium-cooled fast reactor. Hence, scrubbing of volatile fission product from mixed gas bubble rising in sodium pool is presented in this study. To understand this phenomenon, a theoretical model has been setup based on classical theories of aerosol/vapor removal from bubble rising through liquid pools. The model simulates pool scrubbing of sodium iodide aerosol and cesium vapor from a rising mixed gas bubble containing xenon as the inert species. The scrubbing of aerosol and vapor are modeled based on deposition mechanisms and Fick's law of diffusion, respectively. Studies were performed to determine the effect of various key parameters on wet scrubbing. It is observed that for higher vapor diffusion coefficient in gas bubble, the scrubbing efficiency is higher. For aerosols, the cut-off size above which the scrubbing efficiency becomes significant was also determined. The study evaluates the retention capability of liquid sodium used in sodium-cooled fast reactor for its safe operation.

모사된 GTL공정의 점성액체 매체에서 wake의 특성 (Characteristics of Wakes in a Viscous Liquid Medium of a Simulated GTL Process)

  • 임대호;장지화;강용;전기원
    • Korean Chemical Engineering Research
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    • 제49권5호
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    • pp.571-576
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    • 2011
  • 점성 액체를 사용한 모사된 GTL공정(직경 0.102 m ${\times}$ 높이 1.5 m)에서 기포에 의해 발생되는 wake의 특성을 고찰하였다. 기체의 유속(0.04 ~ 0.12 m/s)과 액상의 점도(0.001 ~ 0.050 $Pa{\cdot}s$)가 wake의 특성 즉 상승속도, 빈도수, 크기 그리고 체류량에 미치는 영향을 전기저항 탐침법에 의해 결정하였다. 상승하는 단일기포들뿐만 아니라 다중기포의 후면에 형성된 wake 상들도 탐침에 의해 측정된 전기 전도도 요동자료로부터 효과적으로 검침되었다. 유속이 조절되는 압축 여과공기와 CMC 수용액을 각각 분산기체상과 연속액상으로 사용하였다. 실험결과 wake 상의 상승속도와 크기는 기체의 유속 또는 액상의 점도가 증가함에 따라 증가하였다. wake 상의 체류량과 빈도수는 기체의 유속이 증가함에 따라 증가하였는데, 이는 기체유속의 증가에 따라 공정에 유입되는 기체의 양이 증가하기 때문이다. 그러나, 액상의 점도가 증가함에 따라 기포의 크기와 wake의 크기가 증가하기 때문에 wake의 상의 체류량과 빈도수 값은 wake 상의 액상의 점도가 증가함에 따라 감소하였다. Wake 상 체류량의 기체의 체류량에 대한 비율은 0.25~0.48의 범위였으며, 이 비율은 액체점도가 증가함에 따라 증가하였으나 기체의 유속이 증가함에 따라 감소하였다. 본 연구의 실험범위에서 wake 상의 특성들은 운전변수의 상관식으로 잘 나타낼 수 있었다.

기포탑에서 점성수용액의 가스전달에 관한 연구 (A Study on Gas Transfer of Viscous Aqueous Solutions in a Bubble Column)

  • 최일곤;김상렬
    • 한국안전학회지
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    • 제9권3호
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    • pp.67-73
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    • 1994
  • The gas holdup and volumeteric liquid phase mass transfer coefficient with the variation of the concentration of CMC aqueous solution, gas velocity, diameter and area of the draught tube were investigated. As the results of the experiments, the gas holdup and volumetric liquid phase mass transfer coefficient decreased with decreasing the concentration of CMC aqueous solution, increased with increasing the gas velocity and increased with increasing the circulated area ratio of the draught tube.

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