500 kg of wet material at 12% humidity enter a drying tunnel per hour. Air at 60 ° C temperature and 760 mmHg pressure enters the tunnel with a flow rate of 3500 m3 / hour in counter current. The...

500 kg of wet material at 12% humidity enter a drying tunnel per hour. Air at 60 ° C temperature and 760 mmHg pressure enters the tunnel with a flow rate of 3500 m3 / hour in counter current. The partial pressure of the water vapor in this air is 15 mmHg. The pressure of the air at the outlet is 750 mmHg and its temperature is 35 ° C. Partial pressure of water in this air is 30 mmHg.

a) Calculate the mass of water evaporated from the drying tunnel in one hour.

b) Calculate the mass and moisture percentage of the dried material obtained in 1 hour in this dryer.

c) Show that the masses entering and leaving the drying tunnel are equal.