What type of heat exchanger uses a shell and tube design?

The correct answer pertains to the double-tube heat exchanger, which indeed features a shell-like structure but is not classified under the traditional shell and tube heat exchanger format. The core principle of a shell and tube heat exchanger involves the construction of multiple tubes placed within a shell. One set of these tubes carries the hot fluid while another carries the cold fluid, enabling efficient heat transfer between the two.

In practice, the heat transfer occurs as one fluid flows through the tubes while another fluid flows outside the tubes in the shell, allowing it to extract or dissipate heat effectively. This design is widely used in various industrial applications due to its advantages in terms of heat transfer efficiency and capacity to handle high pressures and temperatures.

The other types of heat exchangers mentioned, such as plate heat exchangers, air-cooled heat exchangers, and spiral heat exchangers, utilize different designs and mechanisms for transferring heat, distinguishing them from the classic shell and tube configuration.