Which type of economizer is more commonly used?

The separate economizer is the most commonly used type, primarily because it functions independently from the boiler. This design allows for greater flexibility in operation and maintenance. Separate economizers are typically installed downstream of the boiler and are used to recover heat from the flue gases to preheat the feedwater before it enters the boiler. This preheating process enhances overall thermal efficiency, reduces fuel consumption, and lowers emissions, making it a favored choice in various industrial applications.

Separate economizers also allow for easier modifications in existing systems, as they can be added without requiring a complete overhaul of the boiler setup. This adaptability further contributes to their prevalence in the field. By improving the efficiency of the steam generation process, separate economizers provide significant economic and operational benefits in power engineering applications.