A. Dry air at atmospheric pressure blows over an insulated fl at plate covered with a thin wicking material which has been soaked in ethyl alcohol. The temperature of the plate is 25°C. Calculate the temperature of the air stream assuming that the concentration of alcohol is negligible in the free stream. Also calculate the mass transfer rate of alcohol for a 30 cm2 plate if the free stream velocity is 7 m/s.
B. Helium gas at 25°C and 4 bar is contained in a glass cylin der of 100 mm inner diameter and 5 mm thickness. What is the rate of mass loss per unit length of the cylinder?
