Effect of the Solid Inlet Design on the Continuous Drying of Fine and Ultrafine Sand in a Fountain Confined Conical Spouted Bed

The effect that the solid inlet design has on the continuous drying of sand in a conical spouted bed has been studied. Five designs have been tried, four of which are feeding the solid from the top and the fifth one into the spout. Three internal devices have been tested, a draft tube, fountain confiner, and new solid driver, to drive the solid to the fountain periphery. A hydrodynamic study has been conducted using beds of dry particles to delimit stable systems, which have been used for the drying of sands of two different size ranges. The more efficient operation is attained by distributing the bed onto the annulus or by feeding the solid into the downward section in the fountain periphery. These configurations allow attaining high efficiencies, with the product moisture content being well below specifications and the bed temperature being close to the adiabatic saturation temperature.