The transition to turbulent fluidization in a gas-solid fluidized bed operating from ambient temperature to 1600 °C

Turbulent fluidized bed proves effective in industrial processes due to superior heat and mass transfer and chemical reaction performance. However, understanding the transition to turbulent fluidization remains limited, especially at temperatures exceeding 1000 °C, making it challenging to develop high-temperature fluidized bed applications. This paper presents an experimental investigation on the turbulent fluidization onset velocity (U_c), measured in a 30 mm diameter bed using corundum particles with average diameters from 0.68 mm to 1.58 mm in temperatures from ambient to 1600 °C. Experimental results reveal that U_c increases with temperature up to 600 °C, stabilizes within the 600–1200 °C range, and then decreases above 1200 °C, demonstrating the varying relative significance of hydrodynamic and interparticle forces at different temperatures. To help design and operate high-temperature applications of turbulent fluidization, we developed U_c correlations based on experimental data from both literature sources and this study, covering temperatures of up to 1600 °C and particles of Groups A to D.