Particulate waste wood firing system

In a particulate waste wood firing system which includes the combination of a particulate waste wood material storage container and bottom unloader therefor having a central opening in the bottom of said container, a radially free-sweeping conveyor screw rotatable within said container operable to unload stored particulate material through said opening, a hopper connected to the bottom of said container and disposed immediately below said central opening for receiving discharged particulate material, a control means mounted in said hopper and operably connected to said conveyor screw to selectively vary the amount of particulate material discharged into said hopper in response to a measured accumulation level of particulate material therein, a choke screw conveyor positioned below said hopper for transporting a controllable amount of said material away from said hopper, a rotary feeder positioned at the output end of said choke screw conveyor for segregating constant volume amounts of said particulate material and moving such volume away from said choke screw conveyor, a duct connecting said rotary feeder with a combustion chamber within a particulate material burning means having two material inputs, a means for producing fire within said chamber and an exhaust outlet which leads to a stack, the improvement comprising:

• at least one heated air duct disposed near a base of said combustion chamber and connected to a pressurized source of heated air;
• a grate for receiving and supporting particulate wood waste material from each of said two material inputs, said grate disposed sufficiently above said heated air duct and having selectively adjustable openings therein for developing and controlling a turbulent flow of heated air through said grate from said heated air duct within said combustion chamber and for developing a high temperature gradient from immediately beneath said grate to the area above said grate;
• a plurality of spaced parallel beams transversing said combustion chamber in a plane above said heated air duct and below said particulate material inputs;
• a plurality of parallel rows of bricks, each said row comprised of a plurality of individual bricks arranged in abutting fashion perpendicular to and directly and removably supported by said beams in a single plane;
• and a plurality of spacers directly and removably supported on said beams and disposed between at least some adjacent rows of bricks, said spacers maintaining said selected open area between said adjacent rows of bricks to control flow of heated turbulent air from said heated air duct through said grate.