Biomass fueled furnace

Claim 1

A hot air furnace including: A. a combustion chamber, said chamber being provided with means to accept a charge of combustible materials initially filling a major portion of it; B. a chimney open to and extending upwardly from the combustion chamber; C. a heat exchange jacket adjacent to, encompassing and spaced from a major portion of said chimney, said jacket being provided with an upper opening adjacent an upper portion of said chimney and a lower opening adjacent said combustion chamber; D. first fan means adjacent one of said jacket openings for moving air into said jacket by way of a first of said openings, through said jacket and out of said jacket by way of a second of said openings; E. second fan means open to the interior of said combustion chamber and adapted, when operable, to supply a forced draft of combustion air to the interior of said chamber; F. temperature sensor means situated to monitor the temperature of air discharging from said second jacket opening; G. control means to render said second fan means operable when said discharging air temperature is below a predetermined temperature range and to render said means inoperable when said air temperature is above said range; H. said heat exchange jacket being also adjacent to, encompassing and spaced from a major portion of said combustion chamber; I. said lower opening in said heat exchange jacket being adjacent a lower portion of said combustion chamber; J. said chimney being constituted as a plurality of spaced apart chimney stacks open through a top wall of said combustion chamber and terminating above said chamber; K. said first fan means being situated adjacent said lower heat exchange jacket opening; L. said means to provide access to load fuel into said combustion chamber being constituted as openable door means, which, when closed, constitutes a front wall of the combustion chamber; M. said second fan means being mounted with respect to a first substantially vertical combustion chamber wall and being open through said first vertical wall to the interior of said combustion chamber; N. said combustion chamber being provided with a second substantially vertical wall in substantially opposed relationship with respect to said first wall; O. said heat exchange jacket being provided with an upright wall in adjacent, parallel, spaced-apart relationship with respect to said second combustion chamber vertical wall; P. said heat exchange jacket vertical wall being provided with said lower opening therethrough; and Q. a baffle plate being integrally connected between top edges of said combustion chamber second vertical wall and said heat exchange jacket vertical wall, said baffle plate being provided with a plurality of drying air transmitting openings therethrough.