Ammonium nitrate, with a moisture content of 20 wt% (dry basis), is to be fed into a direct- heat rotary dryer at a feed rate of 80 lb/min (dry basis) and a temperature of 70 F. Air at 240 F and 1 atm, with a humidity of 0.02 lb HO/lb dry air enters the dryerat the feed end and passes co currently with the solid through the dryer. The final moisture content of the solid is to be 1 wt% (dry basis). Assume all drying takes place in the constant-rate period. Estimate the dryer diameter and length. Data: Cp = 0.4 Btu/lb.F AHvap = 1033 Btu/lb NT = 1.5 H20(1) = 1 Btu/lb. F PH20(g) = 0.447 Btu/lb. F T=135F ds