Comparison with Regenerative Air Preheaters
It’s important to distinguish this from the other main type of APH:
| Feature | Fin Tube (Recuperative) Air Preheater | Regenerative (Ljungström) Air Preheater |
| Principle | Continuous heat transfer through a stationary metal wall. | Cyclic heat storage/release using a rotating matrix (heat sink). |
| Construction | Bundles of finned tubes in a stationary housing. | Rotating cylinder filled with corrugated metal plates. |
| Leakage | Very low. Sealed boundaries between gas streams. | Inherent leakage. Some mixing of air and flue gas occurs. |
| Fouling | Can be severe; requires soot blowers. | Less prone to plugging, but cleaning is more difficult. |
| Applications | Smaller industrial boilers, furnaces, process heaters. | Very large utility boilers in power plants. |