1) An evaporator is used to concentrate 20 wt % NaOH solution entering at 150°F to a 45 wt% NaOH solution exiting at 200°F. The feed flow rate is 4500 lbM/h. Saturated steam at 29.82 psia is fed to the evaporator.
a) What is the pressure in the vapor space of the evaporator?
b) What is the steam flow rate in lbM/h?
c) What is the heat transfer rate in lbM/h?
d) If the heat transfer area is 100 ft2, what is the overall heat transfer coefficient of the evaporator?
2) Use the solver for multiple-effect evaporator to calculate the heat transfer area and the steam flow rate required for the inputs in Example 8.5.1, with the following change: cp(x) = 4.19 - 3x, boiling point rise due to the solutes is negligible and F=6000 kg/h.
Use the textbook: https://4lfonsina.files.wordpress.com/2012/11/christiegeankoplis-transportprocessandunitoperations.pdf