12 Freezing

Exchanger selections should be made on the basis of governing conditions. Conditions overlooked in sizing an exchanger are frequently the cause of failures. One of the most common results from the freezing of water. Water expands when changing from liquid to ice. Strong forces are generated in this process, enough to crack tubes. Typically, only a few tubes crack, but this is enough, for example, to make a plate-fin bundle worthless, as the tubes are not replaceable. Problems such as this can be avoided if they are addressed at the time the exchanger is selected.

This chapter illustrates some steps that have proved to be beneficial in preventing freezing. Which one is best generally depends on the application.