Heating boiler flue gas system - has inner flue gas discharge pipe surrounded by annular air inlet pipe

摘要

Flue gas discharge system for e.g. central heating boiler, has inner mounted flue gas discharge pipe and concentric surrounding air inlet pipe. Flue gas discharge opening is at some distance outside the air inlet which has a protective housing with a larger diameter than the air inlet pipe. Flue gas discharge pipe (1) is surrounded by annular air inlet pipe (2) to form air inlet opening (3). On top of air inlet (2) fits a cylindrical housing (4) formed of connecting sections (4a,4b). Radial wall section (8) is slightly inclined to form a trough with wall section (7). Air inlet opening (11) is slightly larger than air inlet opening (3). Outlet opening (20) of extension section (13) has a number of concentric rings (21) to prevent birds nesting.