Define minimum fluidization velocity. Derive an expression to obtain
the minimum fluidization velocity in case of a Fluidized Bed.
Calculate the minimum fluidizing velocity for a bed of large particles.
Use the information given for ∈ and ∅ .
Do not use information on ∈ and ∅ .
= 2.93 g/cm3, dp = 1mm,∅ = 0.75, ∈ = 0.5
= 0.01 g/cm3 , = 0.0003 g/cm.s
Explain the need for providing distributor in fluidized beds. Describe
the different types of distributors used in industrial scale.
A shot of gas is injected into a 60 cm ID incipiently fluidized bed of
300 m sand for which Umf = 3 cm/s and ∈ = 0.5. A 5 cm bubble
The rise velocity of the bubble.
The cloud thickness about the bubble.
Draw the sketches of gas streamlines near a single rising bubble for
Davidson model and explain in detail.Show slow cloudless bubble
and fast clouded bubble. Compare Davidson model with other
models for gas flow at bubbles.
Explain and differentiate the overall bed coefficient and local
coefficient with respect to mass transfer in case of fluidized bed.
Develop an expression for mass transfer rate from the Bubbling bed
Describe the counter flow solid circulation model for the vertical
movement of solid in a bubbling fluidized bed.
Discuss the experimental findings for emulsion movement of small
and fine particles with neat diagrams in a fluidized bed.