DOI QR코드

DOI QR Code

Experimental Study of Performance and Bubble Pattern of Air-Lift Pumps with Various Tube Diameters and Submergence Ratios

공기부양 펌프의 관직경과 잠수비 변화에 따른 기포 형상과 성능에 관한 실험적 연구

  • Received : 2013.05.01
  • Accepted : 2013.07.29
  • Published : 2013.09.01

Abstract

An airlift pump can be used to pump liquids and sediments within itself, which cannot easily be pumped up by a conventional method, by using the airlift effect. This characteristic of the airlift pump can be exploited in a DCFC (Direct Carbon Fuel Cell) so that molten fuel with high temperature may be carried or transported. The basic characteristics of airlift are investigated. A simple system is constructed, where the reservoir is filled with water, a tube is inserted, and air is supplied from the bottom of the tube. Then, water is lifted and its flow rate is measured. Bubble patterns in the tube are observed in a range of air flow rates with the parameters of the tube diameter and submergence ratio, leading to four distinct regimes. The pumping performance is predicted, and the correlation between the supplied gas flow rate and the induced flow rate of water is found.

공기부양 펌프는 액체 내 공기부양 효과에 의해 양수 조작이 어려운 액체 및 액체 내의 침전물을 손상 없이 토출할 수 있는 장점을 가지고 있다. 이러한 장점을 이용하여 DCFC(Direct Carbon Fuel Cell)에서 고온의 용융된 연료를 혼합 및 순환시키기 위해 공기부양 펌프를 적용할 수 있다. 이를 위한 연구의 일환으로 공기부양 특성을 파악하기 위한 기초 실험을 수행하였다. 본 실험에서는 공기부양 펌프 시스템을 구축하여 저수통 내에 모사 액체로 물을 채우고 관(tube)을 삽입한 후, 관 하단부에 가스유량을 공급하여 상단부의 토출유량을 측정하였다. 설계 인자로서 관직경과 잠수비를 변경하면서 이에 맞는 공기유량을 공급하였고, 정해진 각 조건에서 생성된 관 내부의 기포(bubble) 형상을 디지털 카메라로 촬영, 그 형상을 네 단계로 구분하였다. 펌프의 성능을 이론식을 모델링하여 실험 데이터와 비교하였고, 토출 유량을 측정하여 물이 토출되는 시작점인 가스유량과 전체 유량비와의 상관관계를 분석하였다.

Keywords

References

  1. Nicklin, D.J., 1962, "Two-Phase Bubble Flow," Chemical Engineering Science, Vol. 17, pp. 693-702. https://doi.org/10.1016/0009-2509(62)85027-1
  2. Reinemann, D.J., Parlange, J.Y. and Timmons MB., 1990, "Theory of Small-Diameter Airlift Pumps," Int. J. Multiphase Flow, Vol. 16, No. 1, pp. 113-122. https://doi.org/10.1016/0301-9322(90)90042-H
  3. Lee, S.C., Song, J.H., Jeon, C.H. and Jang, Y.J., 2011, "Measurement of Viscosity and Fluid Characteristics for Molten Carbonate Electrolyte," Trans. Korean Soc. Mech. Eng. B, Vol. 35, pp. 155-158.
  4. Janz, G.J., Allen, C.B. and Bansal, N.P., 1979, "Physical Properties Data Compilations Relevant to Energy Stroage," Rensselaer Polytechnic Institute, New York, pp. 384-395.
  5. Nakoryakov, V.E., Kashinsky, O.N. and& Kozmenko, B.K. 1986, "Experimental Study of Gas-liquid Slug Flow in a Small Diameter Vertical Pipe," Int. J. Multiphase flow, Vol. 12, pp. 337-355. https://doi.org/10.1016/0301-9322(86)90012-1
  6. Kouremenos, D.A. and Staicos, J., 1985, "Performance of a Small Air-Lift Pump," Int J. Heat & Fluid Flow, Vol. 6, No. 3, pp. 217-222. https://doi.org/10.1016/0142-727X(85)90016-5
  7. White, E.T. and Beardmore, R.H., 1962, "The Velocity of Rise of Single Cylindrical Air Bubbles Through Liquids Contained in Vertical Tubes," Int. J. Multiphase Flow, Vol. 17, pp. 351-362.
  8. Nickens, H.V. and Yannitell, D.W., 1987, "The Effects of Surface Tension and Viscosity on the Rise Velocity of a Large Gas Bubble in a Closed, Vertical Liquid-Filled Tube," Int. J. Multiphase Flow, Vol. 13, No. 1, pp. 57-69. https://doi.org/10.1016/0301-9322(87)90007-3
  9. Hanafizadeh, P., Ghanbarzadeh, S. and Saidi, M.H., 2011, "Visual Technique for Decection of Gas-Liquid Two-Phase Flow Regime in the Airlift Pump," Journal of Petroleum Science and Engineering, 75, pp. 327-335. https://doi.org/10.1016/j.petrol.2010.11.028
  10. Moisidis, C.T. and Kastrinakis, E.G., 2010, "Pressure Behaviour in Riser Tube of a Short Airlift Pump," Journal of Hydraulic Research, Vol. 48, No. 1, pp. 65-73. https://doi.org/10.1080/00221680903568642
  11. Kassab, S.Z., Kandil, H.A., Warda, H.A. and Ahmed, W.H., 2009, "Air-Lift Pumps Characteristics Under Two-Phase Flow Conditions," International journal of heat and Fluid Flow, Vol. 30, pp. 88-98. https://doi.org/10.1016/j.ijheatfluidflow.2008.09.002
  12. Bendiksen, K.H., 1984, "An Experimental Investigation of the Motion of Long Bubbles in Inclined Tubes," Int. J. Multiphase Flow, Vol. 10, No. 4, pp. 467-483. https://doi.org/10.1016/0301-9322(84)90057-0
  13. Decachard, F. and Delhaye, J.M., 1996, "A Slug-Churn Flow Model for Small-Diameter Airlift Pumps," Int. J. Multiphase Flow, Vol. 22, No. 4, pp. 627-649. https://doi.org/10.1016/0301-9322(96)00003-1