For a certain process requiring air at controlled temperature and humidity, there is needed 6804 Kg of dry air per hour at 20% humidity and 54.4 c. This air is to be obtained by conditioning air at 20% humidity and 21.1 c by first heating, then humidifying adiabatically to the desired humidity and finally reheating the humid air to 54.4c. The humidifying step is to be conducted in a spray chamber. Assuming the air leaving the spray chamber is to be 2.22c warmer than the adiabatic saturation temperature, (i) (ii) (iii) (iv) To what temperature should the air be preheated? At what temperature should the air leave the spray chamber? How much heat will be required for pre and reheating? What should be the volume of spray chamber if hva = 1583 W/m-c? (Nov/Dec '06) (4 x 4 = 16)