1. Plate Heat Exchanger (PHE)
A PHE consists of a series of thin, corrugated metal plates clamped together in a frame. Gaskets seal the plates and direct the fluids into alternating channels.
Advantages:
- High Efficiency: The corrugated plates induce intense turbulence, which breaks up the boundary layer and dramatically improves heat transfer. This allows a PHE to be much smaller than an STHE for the same duty.
- Compact Size: Its footprint can be as little as 10-50% of an equivalent STHE.
- Ease of Maintenance and Expansion: Simply loosening the frame allows access to all heat transfer surfaces for inspection and mechanical cleaning. You can also add or remove plates to change the unit’s capacity.
- Low Fouling: The high turbulence has a self-cleaning effect, making it ideal for fluids that are prone to fouling, like cooling water or viscous liquids.
- Cost-Effective: For standard applications, PHEs offer a lower purchase price and installation cost.
2. Shell and Tube Heat Exchanger (STHE)
A STHE consists of a bundle of tubes enclosed in a cylindrical shell. One fluid flows through the tubes (tube side), and the other flows over the tubes within the shell (shell side). Baffles are used to direct the shell-side flow and support the tubes.
Advantages:
- High Pressure & Temperature Capability: The robust cylindrical construction makes it ideal for high-pressure applications (e.g., steam heaters, reactor coolers). They are the default choice for extreme conditions.
- Robustness and Reliability: Simple, proven design with a long service life. Fewer seals than a PHE.
- Wide Application Range: Can handle a vast range of fluids, including those with large particulates (on the shell side) and gases.
- Familiar Technology: The design and operational behavior are well-understood by engineers globally.