A spray drier with a 5 m diameter and 10 m height is used to dry skim milk to a final moisture content of 5%. The air entering the drier is 120C, is heated from ambient air at 25C and 75% RH, and flows concurrently with the product droplets (and particles) through the system. The air flow rate is 1000 m3/min. The skim milk enters the dryer at 45C with 90.5% moisture content and the exit temperature is 55C. The specific heat of product solids is 2.0 kJ/kgK. The heated air leaves the system at 5C above the product temperature. Determine a. The production rate for the system; kg of 5% moisture content product per unit time. b. The temperature and % RH of air leaving the dryer. c. The thermal energy for heating the air entering the dryer.