What are the advantages of plate heat exchangers over shell-and-tube?

Advantages include: higher heat transfer coefficients (3-5x higher due to turbulent flow in thin channels), more compact design (smaller footprint and less floor space), closer temperature approach (1-2C vs 5-10C), easy maintenance (plates can be added or removed), flexible capacity (add/remove plates), and better temperature control. Limitations include lower pressure/temperature limits (typically <25 bar, <150C for gasketed), not suitable for fouling fluids, and higher pressure drop.