Effect of Bed Height, Bed Diameter and Particle Shape on Minimum Fluidization in a Gas-Solid Fluidized Bed

Abstract

In this paper parameters most likely to effect pressure drop and particle behavior in gassolid fluidized bed is investigated. These parameters included bed height, bed diameter, and particle shape. For the experiments two laboratory scale fluidized bed systems were used one having a 3.5cm inner diameter and a second having a 12.4cm inner diameter to test the effect of bed diameter. The effect of particle shape was also investigated by testing different shapes of particles ranging from 0.85 to 1.0mm. Also, the bed height varied from 2 to 7 cm. Overall, it is observed that minimum fluidization velocity decreases with decrease of bed diameter. It was also determined that the minimum fluidization velocity did not show a significant variation with bed height. Testing particle shape showed spherical particles requires more pressure drop to reach a minimum fluidization velocity compared to non-spherical particles. Digital imaging of the particle was also recorded to observe incipient minimum fluidization, bubble flow, bubble shape, and particle collisions in the fluidization regime.