Question $2$:

The following data in Table Q$.2$ were obtained when drying a wet sample of material in the

laboratory.

Table Q$.2$

The surface area of sample exposed to the drying medium is $0\mathrm{.}186m^2.$ The weight of the bone

dry solid $($Ls$)$ is $3\mathrm{.}765kg.$

$($i$)$ Draw the rate of drying curve and label clearly the different drying periods.

$[15$ marks$]$

$($ii$)$ Determine the critical moisture content $x_c,$ the equilibrium moisture content $x_e$ and the

constant rate of drying, $R_c.$

$[10$ marks$]$

$($iii$)$ What is the time required to dry a similar sample from an initial moisture content of $0\mathrm{.}27$

$(Kg{H}_2\frac{O}{k}g$ dry solid$)$ to a final moisture content $0\mathrm{.}15.$

$[15$ marks$]$