Comparison of the flow structures and regime transitions between a cylindrical fluidized bed and a square fluidized bed.

Gas-solids flow structures between a circular fluidized bed and a square fluidized bed were compared by differential pressure drops and solids holdups. The flow regime transition from bubbling to turbulent fluidization in the fluidized bed was studied by the standard deviations of pressure drop and solids holdup. The geometry effect on the regime transition was also discussed by comparing the local solids holdup profiles and instantaneous solids holdup signals between the circular and square beds. The frequency and duration time of the changeover between the dilute and dense phases around the transition progress were also studied by statistically analyzing the solids holdup signals in both the square and circular beds. Unlabelled Image • Comparison of the flow structures between a smaller circular bed and a larger square bed. • Study on the local transition around the turbulent fluidization regime. • Scale-up and geometry effects on BFB to TFB transition progress. • Dynamic bubble behavior and dilute-dense phase changeover during regime transition. [ABSTRACT FROM AUTHOR]