An Experimental Study on Effects of Applying the Pulsating Flow to a Gas-Solid Fluidized Bed

Authors: Rezvan Alamian, Alireza Baniassadi, Hassan Basirat Tabrizi

Abstract:

There have been widespread applications of fluidized beds in industries which are related to the combination of gas-solid particles during the last decade. For instance, in order to crack the catalyses in petrochemical industries or as a drier in food industries. High capacity of fluidized bed in heat and mass transfer has made this device very popular. In order to achieve a higher efficiency of fluidized beds, a particular attention has been paid to beds with pulsating air flow. In this paper, a fluidized bed device with pulsating flow has been designed and constructed. Size of particles have been used during the test are in the range of 40 to 100μm. The purpose of this experimental test is to investigate the air flow regime, observe the particles- movement and measure the pressure loss along the bed. The effects of pulsation can be evaluated by comparing the results for both continuous and pulsating flow. Results of both situations are compared for various gas speeds. Moreover the above experiment is numerically simulated by using Fluent software and its numerical results are compared with the experimental results.

Keywords: Fluidized bed, pulsating flow, gas-solid particles, pressure loss, experiments, Fluent.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1333973

References:

[1] D. Kunii, O. Levenspiel, Fluidization Engineering. 2nd ed., Japan, Fukui City, Fukui Institute of Technology, Corvallis, Oregon State University, Chemical Engineering Department, (1991).
[2] L. Massimilla, G. Donsi and C. Zucchini, "The Structure of Bubble-Free Gas Fluidized Beds of Fine Fluid Cracking Catalyst Particles," Chemical Engineering Science, 27, (1972), p. 2005-2015
[3] M. Kobayashi, D. Ramaswami and W.T. Brazelton, "Pulsed Bed Approach to Fluidization," AIChE Syrup. Ser., 66, (1970), p.47-57
[4] H.W. Wong and M.H.I. Baird, "Fluidization in a Pulsed Gas Flow," Chem. Eng. J., 2 (1971), p. 104-113
[5] D. Zhang, M. Koksal, "Heat Transfer in a Pulsed Bubbling Fluidized Bed," Powder Technology, Vol. 168, (2006), p. 21-31
[6] M. Chyang , Y.C. Lin, "Influence of the Nature of the Roots Blower on Pressure Fluctuations in a Fluidized Bed," Powder Technology, Vol. 127, (2002), p. 19-31
[7] F.A. Zenz, D.F. Othmer, "Fluidization and Fluid Particle Systems," Van Nostrand Reinhold, New York, (1960).
[8] S. Ergun, "Fluid through Packed Columns, Chemical Engineering Progress," Vol. 48, (1952), p. 89-94
[9] J.G. Yates, Fundamentals of Fluidized-Bed Chemical Processes, 1st ed. (book style)., London, University College, Department of Chemical and Biochemical Engineering, (1983).
[10] D. Geldart "Types of Gas Fluidization," Powder Technology, Vol. 7, (1973), p. 285-292
[11] D. Geldart, A.R. Abrahamsen, "Homogeneous Fluidization of Fine Powders Using Various Gases and Pressures, Powders Technology," Vol. 19, (1978), p.133-136
[12] A. Haider, O. Levenspiel, "Drag Coefficient and Terminal Velocity of Spherical and Nonspherical Particles," Powder Technology, Vol. 58, (1989), p. 63-70