Abstract:

The mechanism for drying paste materials was investigated in a fluidized bed with inert particles and submerged heating tubes. The correlation equations were obtained for the drying time and specific evaporation rate of water, from which the drying performance can be predicted. The paste TiO₂ material was dried in a fluidized bed in pilot plant with inert particles and submerged heating tubes. The paste material was sprayed in droplet to the surface of inert particles in the range of 200—400 μm with air-blast nozzles. The appropriate drying parameters, operation parameters and equipment parameters were explored. The results show that this drying technology enhances the heat transfer and the paste material with high viscosity can be effectively distributed into the fluidized bed, with uniform temperature in the bed, large flexibility of operation, and low energy consumption. The new drying equipment has high drying capacity, and the heat transfer coefficient is more than 300 W·m^-2·K^-1.