Shell and Tube Heat Exchanger Shell and tube heat exchangers are one of the most commonly used types of heat exchangers in industrial processes. These devices facilitate the transfer of heat between two fluids, typically one hot and one cold, to either cool or heat one of the fluids. A shell and tube heat exchanger consists of a series of tubes inside a larger cylindrical shell One fluid flows through the tubes, while the other flows around the tubes within the shell, separated by the tube walls