Fluid Dynamics of a Spouted Bed with a Fountain Deflector

Abstract

Spouted beds can be applied in various operations; even so, they have limited industrial use. Therefore, internal accessories and variations in their configuration have been studied. In this study, an uncommon device known as a fountain deflector was inserted into a conventional conical spouted bed to evaluate its influence on particle elutriation and on the hydrodynamics of the bed operating with dried papaya seeds. The physical characterization of the particles was carried out considering both their individual properties and those of the porous medium formed by them. The main characteristic of the seeds is their low apparent density (610 kg/m3) and the formation of a bed with a high porosity (0.73). The fluid dynamic curves were obtained for the equipment without a deflector and with the deflector positioned at 15 cm in relation to the conical base of the bed. It was noticed that the presence of the deflector reduced particle elutriation, without significantly affecting the values of the fluid dynamic parameters. The CFD simulation results showed the particle retention effect of the deflector, where it limits the maximum spoutable bed height and reduces the drag. A reduction in particle size distribution was observed when operating with the deflector at high air velocities. Therefore, this study contributed to the evaluation of a rarely used device that demonstrates potential for use in industrial applications. The findings suggest that the deflector can act by maintaining a stable spouting and reducing particle elutriation, also showing potential to promote particle breakage.