Slabs of filter cake with a bone-dry density of 1,600 kg/m3 are to be dried from an initial free-moisture content of 110% (dry basis) to a final free-moisture content of 5% (dry basis) batchwisein trays that are 1 m long by 0.5 m wide, with a depth of 3 cm. Drying will take place from thetop surface only. The drying air conditions are 1 atm, 200oF, and a 100oF wet-bulb temperature.The air velocity across the trays is 3.5 m/s. Experiments under these drying conditions show acritical free-moisture content of 70% (dry basis), with a linear falling-rate period from Xc to X*.Determine:
(a) drying time for the constant-rate period;
(b) drying time for the falling-rate period.