An air heater for an industrial application consists of an insulated, concentric tube annulus, for which air flows through a thin-walled inner tube. saturated steam flows through the outer annulus, and condensation of the steam maintains a uniform temperature on the tube surface. consider conditions for which air enters a 50-mm diameter tube at a pressure of 5 atm, a temperature of 17°c, and a flow rate of 0.06 kg/s , while saturated steam at 2.455 bars condenses on the outer surface of the tube. if the length of the annulus is 8 m, what are the air mean outlet temperature and air pressure drop from inlet to outlet? what is the mass rate at which condensate leaves the annulus? evaluate the properties of air at 325 k.