Central heating boiler - has hot gas flue between reverse flow combustion chamber and combustion space wall

摘要

The central heating boiler has a reverse-flow combustion chamber in a horizontal cylindrical combustion space. Between the chamber (5) and the wall (1) of the space (2) is a hot-gas flue (7) without accessories, and an after-heating surface (8) forms an axial extension of the chamber. This surface can form more than 50% pref. 65% of the total heat-exchange surface of the boiler, and can be formed by pocket-type passages with lateral embossed portions.