Material hold-up on inert particles in fluidized bed dryer

Abstract

In this paper the influence of process parameters on the material hold-up in a fluidized bed dryer with inert particles was investigated. The experiments were performed in a pilot-scale dryer with a cylindrical column 0.215 m in diameter and 1.2 m height, with glass spheres of diameters dp = 1.20 mm and 1.94 mm as inert particles. The material used for drying was NaHCO3 slurry of two different concentrations, 10 and 20 wt.%. Dynamics of the material hold-up was determined for four different drying temperatures, in the range from 60 to 120°C by taking the samples of coated particles during the drying process and measuring the mass with and without the coated material film. The obtained results showed strong positive dependence of the material hold-up on the initial slurry concentration as well as on the drying temperature. The rate of the material film coating formation is quicker at higher drying temperatures.

Keywords

• drying
• slurry
• powder material
• process parameters
• concentration
• temperature