5,000 lb/h of wet isophthalic acid crystals with 30 wt% moisture (wet basis) at 30°C and 1 atm enter an indirect-heat, steam-tube rotary dryer, where they are dried to a moisture content of 2 wt% (wet basis) by 25 psig steam (14 psia barometer) condensing inside the tubes. Evaporation takes place at 100°C, which is also the exit temperature of the crystals. The specific heat of isophthalic acid can be taken as 0.2 cal/g-oC. Determine:

(a) The rate of evaporation of moisture.

(b) The rate of heat transfer.

(c) The quantity of steam required in lb/h.