Improved flue gas control system, for stove or boiler, has 2-position hinged shutter varying flue gas exit route to suit fuel type or other operational condition

摘要

When stove is burning solid fuel, combustion products enter circular section flue at back of combustion chamber through restricted gap, constituting segment of circle left below part-circular baffle (3). When liquid or gas fuel is used, this segment is covered by flap (4), hinged at front, and flue gases escape from base of combustion chamber through duct (2), whose exit into flue is, in solid fuel case, closed by hinged flap. Gas flow in the duct can be obstructed by baffles, to improve the overall available heat output. The flap is also raised, to prevent combustion occurring in the flue when adding solid fuel to a glowing hearth, by a mechanical connection from the stoking door. This is an improved variation of French patent No. 97 02001(20.02.97(qv).