Patent ID: 8186286
Filing Date: 2012-05-29
Classification: F23G,F23L,F23N,Y02E

Abstract:
1. A boiler comprising: a) an enclosure having a door and defining a primary burn chamber adapted to receive a combustible biomass material and coupled to an exhaust gas port open to the environment; b) a plurality of primary combustion air conduits coupled to said primary burn chamber and having a plurality of orifices exposed to the interior of said primary burn chamber; c) a secondary burn chamber coupled to receive exhaust gases and ash from said primary burn chamber; d) a secondary combustion air conduit mounted adjacent an ash collection surface of said primary burn chamber and an inlet port to said secondary burn chamber and having an interior cavity space and a plurality of orifices in air flow communication with said interior cavity space; e) a plurality of tubular exhaust gas conduits extending externally from said secondary burn chamber to said exhaust gas port and having bores formed to produce turbulence in exhaust gases conducted through said bores; f) a source of pressurized combustion air coupled to said primary and secondary combustion air conduits at said primary and secondary burn chambers and controlled to 1) direct air through the primary combustion air conduit orifices to positively pressurize the primary burn chamber and direct combustion exhaust gases containing hydrocarbons past said secondary combustion air conduit and 2) direct air from the secondary combustion air conduit orifices to produce a turbulent air and exhaust gas mixture sufficient to combust hydrocarbons in the mixture prior to entering the secondary burn chamber; and g) a heat exchanger having an enclosure surrounding said primary and secondary burn chambers and said plurality of exhaust gas conduits and containing a liquid heat exchange media and means for circulating said liquid media through said enclosure.