Worked Example

As a process engineer in a juice manufacturing plant, you have been asked to install a heat exchanger for the process's sterilization unit. Your task is to come up with the best flow arrangement. The process requirement is that the hot stream to the unit enters at $125C$ and exits at $90C,$ while the cold stream enters at $25C$ and exits at $80C.$

Show that the counter current gives the best arrangement economically in terms of superior temperature driving forces and equipment size.