Abstract:

The drying of paste materials was experimentally carried out in a vibrated fluidized bed with inert particles and immersed heating tubes.The effects of operating variables, such as feeding rate, vibration condition, gas temperature, gas velocity and power of heating tubes were researched.The heat transfer performance was evaluated with volumetric heat transfer coefficient, and a correlation to calculate volumetric heat transfer coefficient was established.The experimental results showed that heat transfer and mass transfer could be enhanced by vibration and internal heating.The heat efficiency could be up to 60%, with drying capacity over 300 kg·m^-3·h^-1 and volumetric heat transfer coefficient 25 kW·m^-3·K^-1.The particle size distribution of the product was narrow, which was analyzed by using a laser particle-size analyzer.A powder product with average diameter of 0.35 μm and specific surface area of 5.024 m²·g^-1 could be obtained directly by the vibrated fluidized bed.