USCG Exam PracticeThermodynamics and heat exchangers
In a shell-and-tube heat exchanger, what is the primary purpose of baffles installed in the shell?
- A. To prevent the tube bundle from expanding and buckling
- ✓ To direct the shell-side fluid across the tube bundle, raising velocity and turbulenceCorrect
- C. To separate the two fluid streams and prevent mixing
- D. To allow one tube sheet to float and accommodate thermal expansion
Why B is correct
Per DOE-HDBK-1018 Vol.1 §2-1, baffles in the shell direct the shell-side fluid back and forth across the bundle to raise velocity and turbulence, which improves heat transfer. Thermal expansion accommodation is handled by a floating tube sheet or U-bent tubes, not by baffles.
Cited:DOE-HDBK-1018 Vol.1 §2-1