Furnace firing apparatus and method for burning low volatile fuel

An apparatus for burning particulate fuel comprising:

• means defining a chamber for combusting fuel, said combustion chamber having a pair of openings extending therethrough;
• a first burner for discharging a first stream of particulate, air-suspended fuel into a primary combustion zone of said combustion chamber;
• a second burner for discharging a second stream of particulate, air-suspended fuel into a secondary combustion zone of said combustion chamber, said second burner being adjustable and aligned such that said second stream of fuel entrains combustion products from said primary combustion zone;
• and
• a pair of plenum chambers attached to said combustion chamber for introducing air into said primary and secondary combustion zones via said openings in said combustion chamber to support combustion of said fuel.

A method of burning particulate fuel which is comprised of the steps of:

• discharging a first stream of fuel into a primary combustion zone of a combustion chamber;
• igniting said first stream of fuel;
• discharging a second stream of fuel into a secondary combustion zone of said combustion chamber;
• aligning said second stream of fuel so that said second stream of fuel entrains combustion products from said primary combustion zone;
• and
• controlling the amount of said combustion products which are entrained into said secondary combustion zone by adjusting the alignment of said second stream of fuel.

In a method of burning particulate fuel of the type wherein a stream of fuel is discharged into a primary combustion zone of a combustion chamber and ignited, the improvement comprising the steps of:

• discharging a stream of fuel into a secondary combustion zone of said combustion chamber;
• aligning said stream of fuel discharged into said secondary combustion zone so that said stream of fuel discharged into said secondary combustion zone entrains combustion products from said primary combustion zone;
• and
• controlling the amount of said combustion products which are entrained into said secondary combustion zone by adjusting the alignment of said stream of fuel discharged into said secondary combustion zone.