Furnace burner for combusting solid particulate fuel

Abstract

A furnace burner for combusting solid particulate fuel comprises a drum configured for containing the solid particulate fuel for combustion. The drum is supported in a burn chamber of a furnace for rotation about a substantially horizontal axis. The drum comprises a combustion portion inside the burn chamber and configured to support combustion of the fuel therein and a drive portion connected to the combustion portion and extending therefrom to an external end disposed outside the burn chamber for operative coupling to a drive system to rotate the drum. The combustion portion is perforated to permit passage of air but not fuel through a peripheral wall of the combustion portion, and comprises one or more interior flights extending axially and angularly of the drum in a manner conducive of movement of the particulate fuel, upon rotation of the drum, towards a downstream end to release fuel consumed during combustion.

1 . A furnace burner for combusting solid particulate fuel, comprising:
 a housing defining a burn chamber arranged for receiving the solid particulate fuel for combustion thereof to generate exhaust gas;   a drum supported in the burn chamber and configured for containing the solid particulate fuel for combustion, wherein the drum is supported for rotation about a substantially horizontal axis;   wherein the drum comprises a combustion portion inside the burn chamber and configured to support combustion of the fuel therein and a drive portion connected to the combustion portion and extending therefrom to an external end disposed outside the burn chamber, wherein the drive portion is arranged for operative coupling to a drive system configured to rotate the drum around the axis;   wherein the drum extends axially from the external end configured to receive the fuel to a downstream end configured to release the fuel that has substantially combusted for disposal to waste;   wherein each of the combustion portion and the drive portion of the drum comprises a tubular peripheral wall encompassing the axis, wherein the peripheral wall of the combustion portion locates a plurality of openings configured to permit passage of air but not the solid particulate fuel therethrough; and   wherein the combustion portion comprises one or more flights disposed on an inner side of the peripheral wall, wherein the one or more flights extend axially and angularly of the drum in a manner conducive of movement of the solid particulate fuel towards the downstream end upon rotation of the drum.   
     
     
         2 . The furnace burner of  claim 1  wherein the openings in the peripheral wall of the combustion portion are distributed across the full circumference thereof. 
     
     
         3 . The furnace burner of  claim 1  wherein the peripheral wall of the drive portion is imperforate. 
     
     
         4 . The furnace burner of  claim 1  wherein the drive portion is sized diametrically smaller than the combustion portion. 
     
     
         5 . The furnace burner of  claim 1  wherein the drive portion is circular cylindrical in shape and the combustion portion is polygonal cylindrical in shape. 
     
     
         6 . The furnace burner of  claim 1  wherein the drum is rotatably supported at or adjacent each of the external and downstream ends and is free of rotational support therebetween. 
     
     
         7 . The furnace burner of  claim 6  wherein, when the combustion portion is polygonal cylindrical in shape, the drum comprises one or more axially-outwardly projecting annular flanges supported on an outer side the peripheral wall of the combustion portion at or adjacent the downstream end of the drum, and the furnace burner further includes a plurality of rollers rotatably supported in the housing and arranged for rolling engagement with the one or more annular flanges at circumferentially spaced positions of the drum. 
     
     
         8 . The furnace burner of  claim 6  wherein the drive portion of the drum is received in a bushing supported by the housing. 
     
     
         9 . The furnace burner of  claim 1 , in combination with a fuel feeding system including a screw conveyor in coaxial alignment with the drum, and the screw conveyor comprises helical flighting, wherein the helical flighting extends into the drive portion. 
     
     
         10 . The furnace burner of  claim 1  wherein the housing is configured to provide an air gap around a full circumference of the drum. 
     
     
         11 . The furnace burner of  claim 1  wherein the peripheral wall of the combustion portion comprises an outer metallic wall and an inner wall of refractory material, wherein the inner wall of refractory material comprises a plurality of axially-extending sections arranged side-by-side in a circumferential direction of the drum. 
     
     
         12 . A furnace for generating heat from combustion of solid particulate fuel, comprising:
 a base arranged for resting on a support surface;   a housing supported on the base;   a burn chamber in the housing and arranged for receiving the solid particulate fuel for combustion thereof to generate exhaust gas;   an inlet in the housing in fluidic communication with the burn chamber and configured for admitting air from an ambient environment of the furnace into the burn chamber for the combustion of the solid particulate fuel;   a heat exchanger supported in the housing outside the burn chamber and in fluidic communication therewith to receive the exhaust gas therefrom, wherein the heat exchanger is configured for transferring heat from the exhaust gas to a heating medium which acts to distribute the heat;   a flue in fluidic communication with the heat exchanger and arranged for releasing the exhaust gas with the heat removed therefrom to the ambient environment of the furnace;   a fan operatively carried by the housing at a spaced location from the burn chamber and arranged to generate an airflow to draw gas from the burn chamber and to the flue so as to define a flow of gas through the furnace; and   a burner configured for combusting the solid particulate fuel, wherein the burner comprises:
 a drum supported in the burn chamber and configured for containing the solid particulate fuel for combustion, wherein the drum is supported for rotation about a substantially horizontal axis; 
 wherein the drum comprises a combustion portion inside the burn chamber and configured to support combustion of the fuel therein and a drive portion connected to the combustion portion and extending therefrom to an external end disposed outside the burn chamber, wherein the drive portion is arranged for operative coupling to a drive system configured to rotate the drum around the axis; 
 wherein the drum extends axially from the external end configured to receive the fuel to a downstream end configured to release the fuel that has substantially combusted for disposal to waste; 
 wherein each of the combustion portion and the drive portion of the drum comprises a tubular peripheral wall encompassing the axis, wherein the peripheral wall of the combustion portion locates a plurality of openings configured to permit passage of air but not the solid particulate fuel therethrough; and 
 wherein the combustion portion comprises one or more flights disposed on an inner side of the peripheral wall, wherein the one or more flights extend axially and angularly of the drum in a manner conducive of movement of the solid particulate fuel towards the downstream end upon rotation of the drum.