Mass Transfer MCQs

Refractory bricks are usually dried in a __________ dryer.

In case of unsaturated air

A solid is being dried in the linear drying rate regime from moisture content X_o to X_F. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture X_o. The drying time for M = (L_s/AR_c) is (where, L = total mass of dry solid, A = total surface area for drying R_c = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids)

For achieving rapid drying rate in a spray dryer, the diameter of the particles in the feed should be in the range of __________ microns (1 mm = 1000 microns).

According to the Fenske equation, what will be the minimum number of plates required in a distillation column to separate an equimolar binary mixture of components A and B into an overhead fraction containing 99 mol% A and a bottom fraction containing 98 mol% B? Assume that relative volatility (α_AB = 2) does not change appreciably in the coloumn.

As the reflux ratio, in a continuous counter-current extraction is increased, the number of stages

Pick out the wrong statement.

During drying operation, it is easier to remove the __________ moisture.

Pick out the wrong statement pertaining to leaching.