Application of computational fluid dynamics for calculating the solid circulation rate in a spout-fluid bed apparatus for dry coating

Computational fluid dynamics was applied to determine the solid circulation rate in a modified Wurster apparatus. Simulations were performed for various particle volumes and spouting gas flowrates. To check the influence of different geometrical parameters such as the diameter of the lower draft tube, entrainment length and deflectors distance to the upper draft tube, solid circulation rates were calculated for the same. In the last stage of the simulations, novel modifications were made to the modelled apparatus wherein a particular new deflector was conceptualized in order to intensify the solid circulation rate within the apparatus. The simulations help to calculate the solid circulation rate and to visualize particle movement for different conditions and in different regions of the apparatus. This model can further help to evaluate and implement modern design changes in devices with a fast circulating dilute spouted bed.