Combustion apparatus

Abstract

An improved solid fuel combustion apparatus intended for use in residential or light commercial settings capable of sustaining a controlled, continuous blue flame burn, resulting in high efficiency heat output with low emissions and low ash. The combustion apparatus is further capable of being thermostatically controlled, turning off combustion of the fuel when a desired temperature is reached and automatically re-igniting when more heat is called for, and also comprises improved safety features.

1 . A combustion apparatus comprising
 a primary combustion chamber, said primary combustion chamber suitably adapted to contain a quantity of solid fuel and to contain gases;   a secondary combustion chamber, said secondary combustion chamber located adjacent to the primary combustion chamber and having a burn region located proximate to the primary combustion chamber, said secondary combustion chamber suitably adapted to contain gases;   a divider disposed between and separating the primary combustion chamber and the secondary combustion chamber, said divider having a first surface located within the primary combustion chamber, a second surface located within the secondary combustion chamber, and at least one aperture passing completely through said divider from the first surface to the second surface such that the primary combustion chamber and the secondary combustion chamber are in communication with each other through said at least one aperture, said divider constructed of a material suitably adapted to absorb and retain heat energy at temperatures exceeding the flash point of said fuel;   an oxygen introduction mechanism suitably adapted to direct measured amounts of oxygen into the primary combustion chamber in a controlled manner and measured amounts of oxygen into the secondary combustion chamber in a controlled manner;   a pressurizing mechanism suitably adapted to supply positive pressure to the primary combustion chamber to create a pressure differential between the gases contained in the primary combustion chamber and the gases contained in the secondary combustion chamber such that the gases contained in the primary combustion chamber are at a higher pressure relative to the gases contained in the secondary combustion chamber; and   an exhaust structure, having a connection end in communication with the secondary combustion chamber, said exhaust structure suitably adapted to remove heated gases from the secondary combustion chamber;   wherein a first burn of the fuel occurs in the primary combustion chamber creating combustion gases and a char fuel bed, the combustion gases are forced through the char fuel bed and through the at least one aperture of the divider into the secondary combustion chamber as a result of the pressure differential between the gases contained in the primary and secondary combustion chambers, a second burn of the combustion gases occurs in the burn region of the secondary combustion chamber, and superheated gases are exhausted out of the secondary combustion chamber through the connection end of the exhaust structure.   
   
   
       2 . The combustion apparatus of  claim 1  wherein the second burn of the combustion gases occurring in the burn region of the secondary combustion chamber is a controlled, sell-sustaining, continuous blue flame burn, resulting in the fully combusted combustion gases achieving temperatures of at least 1600° F. 
   
   
       3 . The combustion apparatus of  claim 1  wherein the divider is constructed of a castable refractory ceramic material. 
   
   
       4 . The combustion apparatus of  claim 1  wherein the divider further comprises a multiplicity of bricks, each said brick being constructed of castable refractory ceramic material, said bricks placed proximate to each other such that at least one gap exists between at least one pair of bricks forming an aperture of the divider. 
   
   
       5 . The combustion apparatus of  claim 1  wherein the oxygen introduction mechanism comprises
 duct work, said duct work suitably adapted to convey oxygen;   at least one primary inlet, each said primary inlet in communication with the duct work, each said primary inlet located in the primary combustion chamber and oriented to direct oxygen onto fuel placed into the primary combustion chamber; and   at least one secondary inlet, each said secondary inlet in communication with the duct work, each said secondary inlet located in the secondary combustion chamber and oriented to direct oxygen into the burn region of the secondary combustion chamber.   
   
   
       6 . The combustion apparatus of  claim 5  wherein the oxygen introduction mechanism further comprises at least one damper, each said damper suitably adapted to be positioned in either an open position or a closed position, such that the open position of each said damper permits oxygen to pass through one or more of said primary and secondary inlets and the closed position of each said damper prevents oxygen from passing through one or more of said primary and secondary inlets. 
   
   
       7 . The combustion apparatus of  claim 6  wherein each of the at least one damper of the oxygen introduction mechanism is further suitably adapted to automatically be positioned in the closed position when operation of the combustion apparatus must cease due to unsuitable environmental conditions, such that in the event of unsuitable environmental conditions the oxygen introduction mechanism ceases to direct oxygen into either the primary combustion chamber or the secondary combustion chamber. 
   
   
       8 . The combustion apparatus of  claim 6  wherein the pressurizing mechanism is powered by electricity and each of the at least one damper of the oxygen introduction mechanism is further suitably adapted to automatically be positioned in the closed position when electric power to the pressurizing mechanism is interrupted, such that in the event of a power interruption to the pressurizing mechanism the oxygen introduction mechanism ceases to direct oxygen into either the primary combustion chamber or the secondary combustion chamber. 
   
   
       9 . The combustion apparatus of  claim 8  further comprising a backup power source to provide electricity to the pressurizing mechanism in the event of an interruption in a primary source of power to the pressurizing mechanism. 
   
   
       10 . The combustion apparatus of  claim 6  further comprising a thermostatic control device, said thermostatic control device being suitably adapted to control the operation of the oxygen introduction mechanism such that when the thermostatic control device calls for heat the thermostatic control device positions each of the at least one damper of the oxygen introduction mechanism in the open position and when the thermostatic control device does not call for heat the thermostatic control device positions each of the at least one damper of the oxygen introduction mechanism in the closed position. 
   
   
       11 . The combustion apparatus of  claim 5  further comprising at least one access door, each said access door providing access into either the primary combustion chamber or the secondary combustion chamber, wherein at least a portion of the duct work is situated proximate to at least one said access door. 
   
   
       12 . The combustion apparatus of  claim 1  wherein the pressurizing mechanism comprises at least one fan suitably adapted to move air into the primary and secondary combustion chambers. 
   
   
       13 . The combustion apparatus of  claim 1  wherein the pressurizing mechanism is integrated with the oxygen introduction mechanism. 
   
   
       14 . The combustion apparatus of  claim 1  further comprising a heat exchanger, said heat exchanger being in communication with the exhaust structure. 
   
   
       15 . The combustion apparatus of  claim 14  wherein the heat exchanger is located remotely from the secondary combustion chamber in such a manner that heated gases moving from the secondary combustion chamber through the exhaust structure to the heat exchanger must move at least partially in a downward direction prior to reaching the heat exchanger. 
   
   
       16 . The combustion apparatus of  claim 1  further comprising a thermostatic control device, wherein said thermostatic control device is suitably adapted to control combustion of fuel and gases contained within the combustion apparatus such that when the thermostatic control device calls for heat fuel and gases within the combustion apparatus are burned and when the thermostatic control device does not call for heat the burning of fuel and gases within the combustion apparatus ceases. 
   
   
       17 . The combustion apparatus of  claim 16  wherein the thermostatic control device controls the operation of the oxygen introduction mechanism. 
   
   
       18 . The combustion apparatus of  claim 1  further comprising
 at least one access door, each said access door providing access into either the primary combustion chamber or the secondary combustion chamber, wherein at least one said access door provides access into the primary combustion chamber; and   a bypass damper, said bypass damper forming a closable communication between the primary combustion chamber and the exhaust structure, said bypass damper suitably adapted to be positioned in either an open position or a closed position, such that the open position of said bypass damper permits gases to pass from the primary combustion chamber directly into the exhaust structure and the closed position of said bypass damper prevents direct communication between the primary combustion chamber and the exhaust structure;   whereby said bypass damper is suitably adapted to be positioned in its open position whenever an access door to the primary combustion chamber is opened.   
   
   
       19 . The combustion apparatus of  claim 1  further comprising
 a heat exchanger, said heat exchanger being in communication with the exhaust structure and located remotely from the secondary combustion chamber in such a manner that heated gases moving from the secondary combustion chamber through the exhaust structure to the heat exchanger must move at least partially in a downward direction prior to reaching the heat exchanger; and   a thermostatic control device, wherein said thermostatic control device is suitably adapted to control combustion of fuel and gases contained within the combustion apparatus such that when the thermostatic control device calls for heat fuel and gases within the combustion apparatus are burned and when the thermostatic control device does not call for heat the burning of fuel and gases within the combustion apparatus ceases;   wherein the divider is constructed of a castable refractory ceramic material;   the oxygen introduction mechanism comprises at least one primary inlet, each said primary inlet located in the primary combustion chamber and oriented to direct oxygen onto fuel placed into the primary combustion chamber, and at least one secondary inlet, each said secondary inlet located in the secondary combustion chamber and oriented to direct oxygen into the burn region of the secondary combustion chamber; and   the second burn of the combustion gases occurring in the burn region of the secondary combustion chamber is a controlled, self-sustaining, continuous blue flame burn, resulting in the fully combusted combustion gases achieving temperatures of at least 1600° F.   
   
   
       20 . The combustion apparatus of  claim 1  further comprising
 a housing, said housing having an outer surface and an interior, and one or more access doors allowing access into the interior, said housing constructed of a heavy-duty metallic material and further comprising insulation within its interior sufficient to allow for safe contact of the outer surface during operation of the combustion apparatus;   wherein said housing is suitably adapted to contain the primary combustion chamber, the secondary combustion chamber, the divider, the oxygen introduction mechanism, at least a portion of the pressurizing mechanism, and at least a portion of the exhaust structure.