A combustion system for a coal fired furnace having a windbox includes a source of a mixture of pulverized coal and air, and a splitter that receives the mixture and splits it into first and second mixed streams. A first nozzle receives the first mixed stream and discharges it into the furnace. A separator receives the second mixed stream and separates it into an air stream and a coal rich stream. An air conduit connected between the separator and the source of the mixture causes at least some of the air stream to be fed back into the mixture. A second nozzle receives the coal rich stream and discharges it into the furnace. A third nozzle receives support air from the windbox and discharges it into the furnace in a combustion supporting relationship with respect to the coal rich stream.

A combustion burner includes a fuel nozzle configured to blow in fuel gas of solid fuel and air, a combustion air nozzle configured to blow in air from the outside of the fuel nozzle, and at least one flame stabilizer arranged on the axial center side at a distal end of the fuel nozzle. The flame stabilizer is arranged at the distal end, and has a flame stabilizing member whose width increases in a direction toward the distal end, and a straightening vane having a plate shape and being arranged on an extension of the flame stabilizing member on the upstream side in a flow direction of the fuel gas. An abrasion-resistant member is arranged on a wide width surface of the flame stabilizer, and an abrasion-resistant member is arranged on at least a part of the straightening vane.

A combustion burner includes a fuel nozzle configured to blow in fuel gas of solid fuel and air, a combustion air nozzle configured to blow in air from the outside of the fuel nozzle, and at least one flame stabilizer arranged on the axial center side at a distal end of the fuel nozzle. The flame stabilizer is arranged at the distal end, and has a flame stabilizing member whose width increases in a direction toward the distal end, and a straightening vane having a plate shape and being arranged on an extension of the flame stabilizing member on the upstream side in a flow direction of the fuel gas. An abrasion-resistant member is arranged on a wide width surface of the flame stabilizer, and an abrasion-resistant member is arranged on at least a part of the straightening vane.

A solid fuel burner is provided with a nozzle that is provided around the central axis of the burner, that includes a straight tube section having an opening opposed to a furnace, and a curved tube section continuous with the straight tube section, and that sprays out, from the opening to the furnace, a fluid mixture which is of a solid fuel and carrier gas of the solid fuel and which is flowing in the curved tube section; a first swirler that gives the fluid mixture a swirl at the burner central axis side of the straight tube section; and a second swirler that gives, at the burner central axis side downstream of the first swirler, the fluid mixture a swirl opposite to that given by the first swirler.

A solid fuel burner is provided with a nozzle that is provided around the central axis of the burner, that includes a straight tube section having an opening opposed to a furnace, and a curved tube section continuous with the straight tube section, and that sprays out, from the opening to the furnace, a fluid mixture which is of a solid fuel and carrier gas of the solid fuel and which is flowing in the curved tube section; a first swirler that gives the fluid mixture a swirl at the burner central axis side of the straight tube section; and a second swirler that gives, at the burner central axis side downstream of the first swirler, the fluid mixture a swirl opposite to that given by the first swirler.

Provided are a burner such as a concentrate burner, a calcine burner, or a matte burner, or a burner using a mixture of these for feeding reaction gas and fine solids into a reaction shaft of a suspension smelting furnace, and a fine solids feeding apparatus for a burner such as a concentrate burner, a calcine burner, or a matte burner, or a burner using a mixture of these. The fine solids feeding apparatus comprises gas outlets in a fine solids discharge channel upstream of a downstream outlet end of the fine solids discharge channel. The gas outlets comprise spiral path guiding members configured to facilitate gas to flow from the gas outlets in a spiral flow path around a center axis A of the fine solids discharge channel.

Provided are a burner such as a concentrate burner, a calcine burner, or a matte burner, or a burner using a mixture of these for feeding reaction gas and fine solids into a reaction shaft of a suspension smelting furnace, and a fine solids feeding apparatus for a burner such as a concentrate burner, a calcine burner, or a matte burner, or a burner using a mixture of these. The fine solids feeding apparatus comprises gas outlets in a fine solids discharge channel upstream of a downstream outlet end of the fine solids discharge channel. The gas outlets comprise spiral path guiding members configured to facilitate gas to flow from the gas outlets in a spiral flow path around a center axis A of the fine solids discharge channel.

The present application provides a tangentially fired boiler. The tangentially fired boiler may include a combustion chamber and an overfire air system positioned about the combustion chamber. The overfire air system may include a number of overfire air windboxes positioned in a horizontal orientation.

The present application provides a tangentially fired boiler. The tangentially fired boiler may include a combustion chamber and an overfire air system positioned about the combustion chamber. The overfire air system may include a number of overfire air windboxes positioned in a horizontal orientation.

A cement kiln burner includes a plurality of columnar or cylindrical flow channels. Outlets of the respective flow channels are disposed on substantially the same plane. A wind velocity adjusting member capable of changing a cross-sectional area at an outlet-side tip-end portion of the flow channel by moving along an axial direction of the flow channel in a state of being in contact with any one of an inner peripheral wall and an outer peripheral wall of the flow channel and not in contact with the other is provided inside at least one of the flow channels.