Experimental investigations of a pseudo-2D spout fluidized bed with draft plates

Spout fluidized beds often prove promising for gas-solid contacting operations involving chemical reactions with changing particle size. However, difficulties may arise during operation, such as unstable spouting, dead zones formation and limited flexibility in adjustment of maximum spoutable height and residence time This can be improved by inserting draft tubes or plates. In this work, the hydrodynamics of a pseudo-2D spout fluidized bed with draft plates was studied by changing the background velocity from 0 to 1.75 m/s with increments of 0.25 m/s and the spout velocity from 10 to 50 m/s with increments of 5 m/s. The distinct flow regimes were identified by capturing high-speed images and Fast Fourier transformation (FFT) of measured pressure signals. In addition, the effects of the entrainment height (in the range of 0.03-0.05 m), static bed aspect ratio (in the range of 1-1.5) and particle properties (for glass and gamma-aluminum oxide particles) on the hydrodynamics were investigated by determining the time-averaged particle volumetric flux by combined particle image velocimetry (PIV) and digital image analysis (DIA) for two regimes namely, spouting-with-aeration (IV) and fluidized bed-spouting-with-aeration (dispersed spout) (VIII). (C) 2013 Elsevier Ltd. All rights reserved