Practice Problem$-2$

A mixture contains three sizes of spherical particles: $25\%$ by volume of $25mm$

size, $40\%$ of $50mm$ and $35\%$ of $75mm.$ These solid particles which have a

density of $1500k\frac{g}{m^3}$ are to be fluidized using water at $20C.$ Water is pumped

through the bed column. If the cross section of the empty bed is $0\mathrm{.}10m^2,$ the

bed height is $1m$ and the bed contains $120kg$ of solid, calculate the followings:

The minimum porosity of the bed

Frictional pressure drop at water flow rate of $3$ liters $\frac{?}{sec}.$