1.Consider a shell-and-tube heat exchanger, operated in a cocurrent configuration to cool a 100 liters/min aqueous process stream (Phase I). The process stream enters the shell side of the heat exchanger at a feed temperature of 90 C. To cool this process stream, a 200 liters/min stream of cooling water (Phase II) is fed at 30 C through the heat exchanger tubes. Based on these operating conditions, please calculate (a) the minimum temperature that the process stream can achieve and (b) what will this minimum temperature be if the heat exchanger is switched to the countercurrent configuration. You may assume that the aqueous process stream is composed of mostly water.

2.Was the pseudo-steady-state (P.S.S.) assumption we used in our quantitative semi-batch (tank-with-cooling coil) heat exchanger example valid? For full credit, you must provide supporting calculations based on the numbers given in that example problem.