What are the different baffle types in shell-and-tube exchangers and their effects?

Segmental baffles (most common): single/double segmental cut affects crossflow pattern and pressure drop. Disc-and-doughnut baffles: alternate flow pattern, lower vibration risk. Rod baffles (NTIW): no tubes in window, excellent for vibration-prone applications. Helical baffles: spiral flow path, lower pressure drop, reduced dead zones. Baffle spacing affects shell-side velocity and heat transfer - closer spacing increases heat transfer coefficient but also pressure drop. Typical baffle cuts are 20-45% of shell diameter.