… is built with two concentric parallel metallic cylinders (tube-in-tube assembly) of different diameter.
The hot gas flows in the center of the inner cylinder while the combustion air flows in the external annulus comprised between the two metallic cylinders. In order to enhance the efficiency and increase the hot air temperature, the annulus passage is provided inside with parallel metallic fins that increase the heat exchange surface and the air turbulence. The gas/air flow can be parallel (same direction) or counter flow (opposite direction) depending on design, working temperature and operating conditions.
The external surface is completely insulated by rock wool lined with aluminum cladding thus minimizing the parasite heat losses.
This type of recuperator is installed with an external holding structure or, also, in self-supporting configuration. The dilatation between the inner and outer cylinders is compensated by integrated expansion joint.
The choice of the kind of steel in the inner cylinder can vary depending on glass recipe and operating temperature. The recuperator is designed in order to make self-cleaning in case of fouling.
The main features are:
- Up to 500 – 600°C in stand-alone installation
- Possibility to install in double stage
- Easy installation
- Easy withdrawal and maintenance
- Extended life