In a shell-and-tube heat exchanger, which component forms the outer surface that contains the shell-side fluid?

• A. Shell
• B. Tubes
• C. End Caps
• D. Baffles

Answer: (A)

The shell is the outer casing that encloses the tube bundle and contains the shell-side fluid. In a shell-and-tube heat exchanger, one fluid flows inside the tubes and the other flows outside the tubes but inside the shell. The shell forms the outer boundary that holds and directs the shell-side flow, with internal baffles guiding the flow across the tubes to boost heat transfer. End caps seal the shell ends, while the tubes define the boundary for the tube-side fluid. So the outer surface containing the shell-side fluid is provided by the shell.