Patent ID: 7770528

Claim:
A solid fuel burner comprising: a fuel nozzle for jetting a fluid mixture of a solid fuel and its carrier gas into a furnace; at least one air nozzle, arranged outside the fuel nozzle, for jetting air; and a flame holder provided at a tip end of a partition separating said fuel nozzle and said at least one air nozzle, said flame holder serving as an impediment to a mixture fluid flowing in said fuel nozzle and air flowing in said at least one air nozzle; wherein at least one additional air nozzle for jetting additional air having a velocity component in the circumferential direction of said fuel nozzle is provided in such a way as to project into said fuel nozzle from the partition of said fuel nozzle toward a solid fuel burner center axis, said at least one additional air nozzle being placed, in the flow path of the fluid mixture as it flows through said fuel nozzle, at a constant cross sectional portion of said flow path upstream of the flame holder; wherein a partition of said at least one additional air nozzle has a configuration to smoothly reduce the sectional area of the flow path of the fluid mixture and smoothly extend the flow path at a downstream side of the flow path portion with the reduced sectional area; wherein at least one outlet of said at least one additional air nozzle is placed on a side of the partition of said at least one additional air nozzle; wherein the fluid mixture and the additional air are jetted from said fuel nozzle after mixing of the fluid mixture and the additional air; and wherein the fuel is burnt after jetting of the fuel from said fuel nozzle.