Boiler with coiled heat exchanger, has coil which is compressible relative to counter bearing in burner casing

摘要

The coil (1) through which water is passed is compressible over a distance (D) against a fixed counter-bearing (8) in the burner casing (7). Spacer elements between the coil turns (4) define a narrow flow gap (6) for hot gases to pass through. The heat exchanger is located inside a burner chamber.