6. Heat exchange with liquid-to-vapor phase transition

The generation or condensation of steam by direct contact, which is commonplace in nature, is often used innocuously in many applications. Examples include the evaporation and condensation of water, the heating of milk by the direct condensation of steam, the spraying and evaporation of water droplets to temper ambient air, the drying of solids, and boiling to separate liquids.... We're going to look at these three mechanisms in turn, all of which involve the liquid-vapor phase transition.