Force characteristic of a large dense object in a fluidized bed equipped with an inclined air distributor

摘要

Large dense objects are easily stagnated over the distributor during fluidization, having serous influence on bed performance. In this study, three-dimensional modeling of the gas-solid flow in a fluidized bed equipped with an inclined air distributor is conducted by means of two-fluid model to explore the characteristics of the force acting on a stagnant object in bottom bed. Images of the instantaneous particle concentration demonstrate the inhomogeneity of transverse gas-solid flow in bottom bed. The influences of gas velocities on the force fluctuation characteristic for object in various positions of the bottom bed are evaluated. Statistical, spectral and wavelet analysis methods are applied to disclose the time-averaged and instantaneous characteristic of the forces. Results show that with the increasing of gas velocity, the transverse movements of bubbles and particles are both intensified, and the latter is more significant. The dominant frequency of the forces on an object along the inclined direction is 0.3-0.5 Hz, which is smaller than that perpendicular to the distributor of 1.2 Hz. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.