'''2. study literature type of particle in fluidized bed? '''

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The Geldart Classification of Particles

Geldart came up with four clearly recognizable kinds of particle behavior. From smallest to largest particle, they are as follows:

Group C: cohesive, or very fine powders. Normal fluidization is extremely difficult for these solids because interparticle forces are greater than those resulting from the action of the gas.

Group A: aeratable, or materials having a small mean particle size and/or low particle density ( < ~ 1.4 g/cm3 ). These solids fluidize easily, with smooth fluidization at low gas velocities and controlled bubbling with small bubbles at higher gas velocities. FCC catalyst is representative of these solids.

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                         Region A': Range of properties for well-behaved FCC catalyst; from Miyauchi et al.

Group B: sandlike, or most particles of size 40 μm < dp < 500 μm and density 1.4 < ps < 4 g/cm3. These solids fluidize well with vigorous bubbling action and bubbles that grow large.

Group D: spoutable, or large and/or dense particles. Deep beds of these solids are difficult to fluidize.