GF$20$

Q$.5.$ What are the conditions of fluidization? Describe the two principal types of

fluidization & distinguish between them. Explain the application of

fluidization in pneumatic conveying of solid particles

OR

Table salt is fed to a vibrating screen at the rate of $300l\frac{b}{h}r.$ The desired

product is the $\frac{48}{65}$ mesh fraction. A $48-$ and a $65-$ mesh screens are

therefore used $($double deck$),$ the feed being introduced on the $48-$mesh

screen, the product being discharged from the $65-$mesh screen. During the

operation it was observed that the average proportion of the oversize:

product: undersize was $2$:$\frac{3}{2}$:$1.$

$($a$).$ Calculate the effectiveness of the screener.

$($b$).$ If the screen dimensions are $2ft$ by $4ft,$ calculate the capacity of the $65-$

mesh screen on the basis of a perfectly functioning $48-$mesh screen and also

on the basis of the actual performance of the screen.