Impacts of U and Inverted U-Bends on Vertical Gas-Liquid Two-Phase Fluids
Keywords:
Downward, Upward, 180o Bend, Film Thickness Probes, Wire Mesh SensorAbstract
The current work is experimentally based which is conducted on the purpose of studying the impacts of U and inverted U-bends on gas/liquid behavior in a vertical upward and downward flow line. The main instruments used are wire mesh sensor (WMS) and
liquid film probes. Both devices are installed at the top and bottom locations of upward and downward sections. Probability density functions (PDFs) and time traces of averaged void fraction are applied to reveal the flow behavior inside this configuration. It is very obvious from achieved results that the flow structure in the adjacent parts of the bends is significantly different from those apart away. These bends act on distribution of the flow and change it from uniform to un uniform in adjacent straight sections of the pipeline. This is attributed to the action of centrifugal and gravitational forces that generated by the bends. The results are further explained by analysis the reconstructed images obtained from Wire Mesh Sensor technique, and circumferential distribution of liquid film that measured by conductive film probes. The data of liquid film profile are consistent with PDFs and time traces data extracted by WMS.
References
References
Abdulkadir, M., D. Zhao, Azzi, A., Lowndes, I. S. & Azzopardi, B. J., 2012. Two-phase airwater flow through a large diameter vertical 180º return bend.Chemical Engineering Science,79, pp.
–152.
Alves, G.E., Co-current liquid-gas flow in a pipeline contactor, 1954. Chemical Engineering
Progress, 50, pp. 449–456.
Oshinowo, T. & Charles, M.E., 1974. Vertical two-phase flow–Part 1: Flow pattern correlations.
The Canadian Journal of Chemical Engineering, 52, pp. 25–35.
Usui, K., Aoki, S., & Inoue, A., 1983. Flow behaviour and phase distributions in two phase flow
around inverted U-bend. Journal of Nuclear Science and Technology, 20, pp. 915–928.
Azzi, A., Friedel, L., Kibboua, R. &Shannak, B., 2002. Reproductive accuracy of two-phase flow
pressure loss correlations for vertical 90 degree bends. Forschung im Ingenieurwesen, 67, pp. 109–
Azzi, A. & Friedel, L., 2005. Two-phase upward flow 90 degree bend pressure loss model.
Forschung im Ingenieurwesen, 69, pp. 120–130.
Spedding, P.L., & Benard, E., 2006. Gas-liquid two-phase flow through a vertical 90 degree elbow
bend. Experimental Thermal and Fluid Science, 31, pp.761– 769.
Shannak, B., Al-Shannag, M., &Al-Anber, Z. A., 2009. Gas-liquid pressure drop in vertically
wavy 90o bend. Experimental Thermal and Fluid Science, 33, pp. 340–347.
Da Silva, M.J., Thiele, S., Abdulkareem, L., Azzopardi, B.J., & Hampel, U., 2010. High resolution
gas-oil two-phase flow visualization with a capacitance wire mesh sensor. Flow Measurement and
Instrumentation, 21, pp. 191–197.
