Title: Numerical study of hydrodynamics in gas-solid reactors operating within bubbling fluidisation regime

Authors: Akhilesh Kumar Sahu; Vasudevan Raghavan; B.V.S.S.S. Prasad

Addresses: Department of Mechanical Engineering, Indian Institute of Technology Madras, India ' Department of Mechanical Engineering, Indian Institute of Technology Madras, India ' Department of Mechanical Engineering, Indian Institute of Technology Madras, India

Abstract: Hydrodynamics of dense gas-solid flows is investigated computationally using Euler-Euler methodology. The method used is primarily based on the kinetic theory of granular flow (KTGF) and additionally by incorporating the features of frictional pressure models (FPM). Frictional stresses are accounted when solid volume fraction reaches the frictional packing limit (FPL). Investigations on the effects of bed pressure drop and other gas-solid flow characteristics have revealed that a value for frictional packing limit around 0.61 yields better results. It is also found that the FPM affects the bed hydrodynamics up to a superficial gas velocity of around 1.5 times the minimum fluidisation velocity. The numerical results of bed pressure drop and bed expansion ratio are validated against the corresponding experimental data available in literature. Detailed velocity and voidage profiles are reported along with the contours of solid volume fraction, and velocity vectors of gas and solid phases.

Keywords: dense gas-solid flows; bubbling fluidisation; frictional pressure model; FPM; superficial gas velocity; minimum fluidisation velocity; frictional packing limit; FPL.

DOI: 10.1504/PCFD.2017.084349

Progress in Computational Fluid Dynamics, An International Journal, 2017 Vol.17 No.3, pp.180 - 192

Received: 04 Jul 2015
Accepted: 06 Jan 2016

Published online: 31 May 2017 *

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