Patent ID: 7954438

Claim:
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 conduits arrayed inside said primary burn chamber and having orifices exposed to the interior of said primary burn chamber; c) a secondary burn chamber coupled to receive exhaust gases from said primary burn chamber; d) a secondary combustion air conduit mounted between said primary and secondary burn chambers having an arcuate surface aligned opposite walls of the secondary burn chamber, containing a plurality of orifices and including a cavity space containing baffles for diverting and delaying airflow through said cavity space and said orifices; e) a plurality of tubular exhaust gas conduits coupled intermediate said secondary burn chamber and said exhaust gas port and having bores formed to produce turbulence in exhaust gases conducted therethrough; f) a source of combustion air coupled to said plurality of conduits at said primary burn chamber and the cavity space of said secondary combustion air conduit and controlled to 1) direct air through the 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 and air and exhaust gas mixture and combustion of the exhaust gases prior to entering the secondary burn chamber; g) a heat exchanger having an enclosure surrounding said primary and secondary burn chambers, said secondary combustion air conduit and said plurality of exhaust gas conduits and containing a liquid heat exchange media and means for circulating said liquid media through said enclosure; and h) means for controlling the flow of exhaust gases from said primary burn chamber and secondary burn chambers and exhaust conduits and through said exhaust gas port.