Evaluation on the effect of conical geometry on flow behaviours in spouted beds

Abstract

Evaluation on the effect of conical section geometry on the gas-solid flow behaviours in conical-cylindrical spouted beds were carried out by three-dimensional computational fluid dynamics (CFD) coupling with two-fluid model (TFM). The simulations were implemented in seven columns with their conical angles ranging from 30° to 180°. The solid flow pattern, particle velocity, voidage, fountain height and the spout diameter were investigated. It was found that unstable spouting would occur when the conical angle is less than 30°. In addition, the conical angle of 105° might be a borderline value for gas-solid flow behaviours in the spout. In this region, increasing conical angle leads to a decrease in fountain height, particle velocity and voidage and an increase in the spout diameter when the conical angle is within 105°, while reverse trends could be found when the conical angle is beyond 105°. The smallest fountain height, particle velocity and voidage and largest spout diameter could be found when the angle is 105°. In spite of these, the particle velocity in the annulus continually increases with increasing conical angle. © 2013 Canadian Society for Chemical Engineering.