Minimum fluidization velocity and reduction behavior of combusted iron powder in a fluidized bed

The fluidization and reduction behavior of micron-sized iron oxide powder, produced by combustion, is studied in a lab-scale cylindrical fluidized bed. minimum velocity umf found to stabilize above normalized static bed heights 0.5 H/D (static height divided the diameter). measured as function temperature between 280 860 K for both H2 N2 fluidizing gas. experimental results start deviate from Ergun correlation at temperatures 560 K, H2. A new correlation, taking cohesive inter-particle solid bridge force into account, proposed this work predict high temperature. Reduction experiments are carried out total time 5 h constant excess with 50, 75 100 vol% 623 823 K. Gradual defluidization occurs when operating exceeds 800 maximum degree 61% obtained 807