Energy Balances with Phase Changes: Example Problems
Try to solve these problems before watching the solutions in the screencasts.
Example Problem 1
Example Problem 3 (optional)
12 mol/min of an equimolar mixture of n-pentane and n-hexane at 20°C is fed continuously to a vessel at some P0 in which the mixture is heated to 65°C. Thirty percent of the pentane in the feed is vaporized. If 40% of the vapor stream is pentane, how much heat must be transferred to the mixture per minute?
Example Problem 2
Superheated steam at 10-bar pressure and 200°C flows at 2 kg/s into a heat exchanger. The steam preheats a reactor feed by transferring 450 kW of heat. The pressure drop across the heat exchanger is negligible. Determine the enthalpy, temperature, and phase of the steam exiting the heat exchanger.