Clean burning furnace method and apparatus

Abstract

A furnace includes a primary and secondary combustion chamber. Heated air from the secondary combustion chamber travels through a vertically-oriented set of flues, and two horizontally-oriented sets of flues before exiting through a chimney.

We/I claim: 
     
         1 . A furnace comprising:
 a housing having a front wall, a rear wall and two side walls; and   a primary combustion chamber positioned within the housing;   a secondary combustion chamber disposed beneath the primary combustion chamber within the housing, the secondary combustion chamber arranged to enable the combustion of gases and other combustion products from the primary combustion chamber;   a heat exchanger positioned within the housing, the heat exchanger including:
 a plurality of vertically-oriented flues configured to form a vertical heat exchange path, the vertically-oriented flues arranged to carry heated air from the secondary combustion chamber towards a top of the housing; 
 a first plurality of horizontally-oriented flues configured to form a first horizontal heat exchange path, the first plurality of horizontally-oriented flues fluidly coupled to the vertically-oriented flues and arranged to carry the heated air from proximate the rear wall of the housing to proximate the front wall; 
 a second plurality of horizontally-oriented flues configured to form a second horizontal heat exchange path, the second plurality of horizontally-oriented flues fluidly coupled to the first plurality of horizontally-oriented flues and arranged to carry the heated air from proximate the front wall of the housing to proximate the front wall; and 
 one or more liquid conduits positioned along the vertical heat exchange path, the first horizontal heat exchange path, and the second horizontal heat exchange path, the liquid conduits configured and dimensioned to enable a heat exchange between the heated air and liquids carried by the liquid conduits; and 
 a chimney fluidly coupled to the second plurality of horizontally-oriented flues.