Transport Processes and Separation Process Principles (Includes Unit Operations) Fourth Edition

8.1. INTRODUCTION

8.1A. Purpose

In Section 4.8 we discussed the case of heat transfer to a boiling liquid. An important instance of this type of heat transfer occurs quite often in the process industries and is given the general name evaporation. In evaporation the vapor from a boiling liquid solution is removed and a more concentrated solution remains. In the majority of cases the separation process called evaporation refers to the removal of water from an aqueous solution.

Typical examples of evaporation are concentration of aqueous solutions of sugar, sodium chloride, sodium hydroxide, glycerol, glue, milk, and orange juice. In these cases the concentrated solution is the desired product and the evaporated water is normally discarded. In a ...