The peanuts will be dried in a cross flow dryer. The initial moisture of peanuts is 80% on wet basis, and the exit moisture is 12% on wet basis at 25 °C. The drying air is first conditioned in a heater. Air enters the heater at 25°C (dry thermometer temperature) and 80% relative humidity. The energy provided by the heater is 84 kJ/kg of dry air. The air leaves the dryer at 90% relative humidity. In the light of this information given:
a-What is the relative humidity of the air leaving the heater?
b- What is the dry bulb temperature of the air leaving the dryer?
c- What is the velocity of the air required to dry 50 kg of peanuts per hour (m3/h) ?