Fluid flow pattern and solids circulation rate in a liquid phase spout‐fluid bed with draft tube

Abstract

Abstract The fluid flow pattern and solids circulation rate in a liquid phase spout‐fluid bed with a draft tube were studied in a semi‐circular column 196 mm in diameter equipped with a semi‐circular draft tube 34.5 mm in diameter using water and spherical glass particles 1.20, 1.94 and 2.98 mm in diameter. Both the solids circulation rate and fluid distribution between the draft tube and the annulus are influenced by the location of the draft tube, the relative magnitude of the inlet spouting and annulus flowrates, and the total fluid flowrate entering the bed. A one‐dimensional steady state model of vertical non‐accelerating liquid‐solids flow predicts the solids mass flux in the draft tube with a mean deviation of 12.3% when experimental values of the axial pressure gradients in the draft tube and annulus are specified. A simple correlation for the fountain height is also presented.