Maple syrup evaporator with biomass burner

Abstract

A burner using biomass combustibles, namely pellet fuel, for a maple syrup evaporator. Compared to wood or oil burning heat sources, pellet fuel is less costly, burns more efficiently and generates the heat necessary to properly evaporate maple sap. The burner includes a burn pit defining a plurality of holes for allowing air to communicate between a combustion chamber and a primary air plenum formed between a base and an underside of the burn pit. An air supply conduit supplies air supply to the primary air plenum. A fuel conduit in communication with the combustion chamber supplies the pellet fuel for combustion within said burn pit. A secondary plenum in pneumatic communication with the primary air plenum receives and cools a portion of the primary air supply. A plurality of injectors in communication with the secondary plenum inject the cooled air into the combustion chamber.

1 . A biomass burner ( 32 ) for a maple sap evaporator comprising:
 a burner assembly ( 36 ) comprising a base ( 54 ) and a top for forming a combustion chamber ( 66 ) therein, said top defining an entrance and an exit;   a burn pit ( 68 ) disposed within said base ( 54 ) and defining a plurality of holes ( 70 ) for allowing air to communicate between said combustion ( 66 ) chamber and a primary air plenum ( 76 ) formed between said base ( 54 ) and an underside of said burn pit ( 68 );   an air supply conduit ( 90 ) for supplying a primary air supply to said primary air plenum ( 76 );   a fuel conduit ( 92 ) in communication with said combustion chamber ( 66 ) for supplying a pellet fuel ( 46 ) for combustion within said burn pit ( 68 );   a secondary plenum ( 102 ) in pneumatic communication with said primary air plenum ( 76 ) for receiving and cooling a portion of said primary air supply; and   a plurality of injectors ( 106 ) in communication with said secondary plenum ( 102 ) for injecting said cooled air into said combustion chamber ( 66 );   wherein when said pellet fuel ( 46 ) undergoes combustion with said primary air supply, a generated heat is directed towards said exit by said injected cooled air.   
     
     
         2 . The biomass burner of  claim 1 , wherein the a plurality of holes ( 70 ) of the burn pit ( 68 ) are evenly distributed thereon. 
     
     
         3 . The biomass burner of  claim 1 , wherein said top is a semi-circular dome ( 56 ). 
     
     
         4 . The biomass burner according to  claim 1 , wherein said exit comprises a cone ( 86 ) for accelerating said heat out of said combustion chamber ( 66 ). 
     
     
         5 . The biomass burner according to  claim 1 , further comprising a hollow divider ( 82 ) projecting from said burn pit ( 68 ) into said combustion chamber ( 66 ) for dividing said supplied pellet fuel into two sub-burn pits. 
     
     
         6 . The biomass burner according to  claim 1 , further comprising a door ( 40 ) for sealing said entrance. 
     
     
         7 . The biomass burner of  claim 6 , wherein said door ( 40 ) is hollowed for providing said secondary air plenum ( 102 ), said door ( 40 ) comprising an inlet for pneumatic communication of said primary air plenum ( 76 ) and said secondary air plenum ( 102 ) and defining a plurality of holes formed within said door ( 40 ) for forming said injectors ( 106 ). 
     
     
         8 . The biomass burner according to  claim 1 , wherein said pellet fuel ( 46 ) is supplied to said burn pit ( 68 ) by an auger screw conveyor ( 114 ) provided in said fuel conduit ( 92 ). 
     
     
         9 . The biomass burner according to  claim 1 , wherein said primary air supply is supplied to said primary and said secondary air plenums ( 76 ,  102 ) via an air blower ( 96 ) connected to said air supply conduit ( 90 ). 
     
     
         10 . The biomass burner according to  claim 1 , wherein said pellet fuel is wood pellet fuel.