Effect of Initial Bed Height and Liquid Velocity on the Minimum Fluidization Velocity (Umf) and Pressure Drop for the Bed of Semolina Particles in Liquid-Solid Fluidization
American Journal of Science, Engineering and Technology
Volume 1, Issue 2, December 2016, Pages: 58-62
Received: Sep. 23, 2016;
Accepted: Dec. 14, 2016;
Published: Jan. 12, 2017
Views 3156 Downloads 106
Usman Asghar, Department of Chemical Engineering, University of Wah, Wah Cantt., Pakistan
Waqar Ali Khan, Department of Chemical Engineering, NFC Institute of Engineering and Fertilizer Research, Faisalabad, Pakistan
Imran Shamshad, Department of Chemical Engineering, NFC Institute of Engineering and Fertilizer Research, Faisalabad, Pakistan
The successful and economical design, scale up and operation of a fluidized bed reactor depends upon the true prediction of its bed hydrodynamics. The present research has been carried out to study the hydrodynamics behavior of bed of semolina particles in liquid solid fluidization. The prime objective of this research work is to study the effect of liquid superficial velocity and variation in static bed height on the minimum fluidization velocity and pressure drop. Liquid-solid fluidization is characterized by the uniform expansion of bed particles, therefore it is known as particulate fluidization. In liquid solid fluidization, there is no bubbling phase, that is the main cause of uniform bed expansion. Liquid-solid fluidization has extensive field of applications, i.e. in hydrometallurgy, waste water treatment, biochemical processing and food technology. Minimum fluidization velocity and pressure drop are important hydrodynamic parameters in the design and scale up of fluidized bed reactors. The experimental work was carried out in a column made up of acrylic having 60mm outer diameter and 2mm wall thickness and was 1000mm long. Manometers were used to observe the pressure drop variations across the bed. The minimum fluidization velocity was found to be 0.404mm/sec. It has been found that the minimum fluidization velocity is not affected by the variations in the initial static bed height. Semolina particles being sticky solids offer slightly greater pressure drop. Pressure drop becomes constant when fluidization is achieved.
Waqar Ali Khan,
Effect of Initial Bed Height and Liquid Velocity on the Minimum Fluidization Velocity (Umf) and Pressure Drop for the Bed of Semolina Particles in Liquid-Solid Fluidization, American Journal of Science, Engineering and Technology.
Vol. 1, No. 2,
2016, pp. 58-62.
Farhana Tisa, Abdul Aziz Abdul Raman, and Wan Mohd Ashri Wan Daud. “Basic Design of a Fluidized Bed Reactor for Wastewater Treatment Using Fenton Oxidation”, International Journal of Innovation, Management and Technology, Vol. 5, No. 2, April 2014.
C. Corre, J. L. Estivalezes, S. Vincent, O. Simonin. Direct Numerical Simulation of a Liquid-Solid Fluidized Bed. In Proc 7th. Int. Conf. on Multiphase Flow, ICMF 2010.
Comte (M. P.), Bastoul, D., Hebrard, G., Roustan, M., Lazarova, V., Hydrodynamics of Three PhaseFluidized Bed-the Inverse Turbulent Bed, Chem. Eng. Sci., 52, 3971-3977, 1997.
J Liang, W. G., Zhang, S. L., Zhu, J. X., Yu, Z. Q., Jin, Y., & Wang, Z. W. (2008). "Flow characteristics of the liquid-solid circulating fluidized bed". Powder Tech., 90, 95–102.
Fan (L. S.), Gas-Liquid-Solid Fluidization Engineering, Butterworths, Boston, USA, 1989.
Femin Bendict (R. J.), Kumaresan, M., Velan, M., Bed Expansion and Pressure Drop Studies in a Liquid-solid Inverse Fluidized Bed Reactor, Bioprocess Eng., 19, 137-142, 1998.
Zhu, J.-X., D. G. Karamanev, A. S. Bassiand Y. Zheng (2000)," (Gas-)liquid-solid circulating fluidized beds and their potential applications to bioreactor engineering". The Canadian Journal of Chemical Engineering 78 (1): 82-94.
Vijay alakshmi (A. C.), Bala murugan, M., Siva kumar, M., Newton, T. S., Velan, M., Minimum Fluidization Velocity and Friction Factor in a Liquid-Solid Inverse Fluidized Bed Reactor, Bioprocess Eng., 22, 461-466, 2000.
A. Aguilar-Corona, R. Zenit, O. Masbernat. Collisions in a liquid fluidized bed. International Journal of Multiphase Flow, 37, pp. 695 - 705, 2011.
Yates, J. G., Simons, S. J. R., 1994, "Experimental methods in fluidization research". International Journal of Multiphase Flow 20 Suppl., 297–330.
Lucas, A., J. Arnaldos, J. Casal, and L. Pulgjaner (1986). "Improved Equation for the Calculation of Minimum Fluidization Velocity". Industrial and Engineering Chemistry Research 26 (3): 633-63.
Asif M. N. Kalogerakis and L. A. Behie. Hydrodynamics of Liquid Fluidized Beds Including the Distributor Region, Chemical Engineering science, vol. 47, No. 15/16, pp 4155-4166, 1992.
Sunun Limtrakul, Jinwen Chen, Palghat A. Ramachandran, Milorad P. Dudukovi´ c, "Solids motion and holdup profiles in liquid fluidized beds". Chemical Engineering Science 60 (2005) 1889–1900.
Escudero, David Roberto, "Bed height and material density effects on fluidized bed hydrodynamics" (2010). Graduate Theses and Dissertations. Paper 11656.
Selçuk, N., Ayranci, I. and Gogebakan, Y., "Effect of Recycle on Radiative Heat Transfer in the Freeboard of a Fluidized Bed Combustor", 18th International Conference on Fluidized Bed Combustion, ASME, Paper No. FBC2005-060, 2005.
Bai, B., Gheorghiu, S., van Ommen, J. R., Nijenhuis, J., Coppens, M.-O., 2005, "Char-acterization of the void size distribution in fluidized beds using statistics of pressure fluctuations". Powder Technology 160, 81–92.