Abstract: A solid fuel burner and method uses a low oxygen concentration gas as a transporting gas for a low grade solid fuel such as brown coal or the like, provides for accelerating ignition of the fuel and for preventing slugging caused by combustion ash. Mixing of fuel and air inside a fuel nozzle 11 is accelerated by an additional air nozzle 12 and a separator 35 for separating a flow passage, arranged in the fuel nozzle 11, and an exit of the additional air nozzle 12 is set at a position that overlaps with the separator 35. Additional air is ejected in a direction nearly perpendicular to a flow direction of a fuel jet flowing through the fuel nozzle 11. The amount of air from the additional air nozzle 12 is varied corresponding to a combustion load, in order to assure stable burning of the fuel, and, to suppress radiant heat received by structures of the solid fuel burner and walls of the furnace.

Abstract: A solid fuel burner using a low oxygen concentration gas as a transporting gas of a low grade solid fuel such as brown coal or the like and a combustion method using the solid fuel burner are provided. The solid fuel burner comprises a means for accelerating ignition of the fuel and a means for preventing slugging caused by combustion ash from occurring. Mixing of fuel and air inside a fuel nozzle 11 is accelerated by that an additional air nozzle 12 and a separator 35 for separating a flow passage are arranged in the fuel nozzle 11, and the exit of the additional air nozzle 12 is set at a position so as to overlap with the separator 35 when seeing from a direction perpendicular to a burner axis, and additional air is ejected in a direction nearly perpendicular to a flow direction of a fuel jet flowing through the fuel nozzle 11. An amount of air from the additional air nozzle 12 is varied corresponding to a combustion load.

Abstract: A solid fuel burner using a low oxygen concentration gas as a transporting gas of a low grade solid fuel such as brown coal or the like and a combustion method using the solid fuel burner are provided. The solid fuel burner comprises a means for accelerating ignition of the fuel and a means for preventing slugging caused by combustion ash from occurring. Mixing of fuel and air inside a fuel nozzle 11 is accelerated by that an additional air nozzle 12 and a separator 35 for separating a flow passage are arranged in the fuel nozzle 11, and the exit of the additional air nozzle 12 is set at a position so as to overlap with the separator 35 when seeing from a direction perpendicular to a burner axis, and additional air is ejected in a direction nearly perpendicular to a flow direction of a fuel jet flowing through the fuel nozzle 11. An amount of air from the additional air nozzle 12 is varied corresponding to a combustion load.

Abstract: According to a burner of the present invention, a stable combustion is obtained in a wide range from a high-load operation condition to a low-load operation condition even in the case of low quality solid fuel such as brown coal. The amount of air supplied from additional air holes or additional air nozzles 12 can be adjusted depending on the combustion load of furnace 41. At a low load, the amount of air supplied from additional air holes or additional air nozzles 12 is increased, whereby the oxygen concentration in a recirculation zones 19 formed downstream of the outside of a fuel nozzle 11 exit, permits a stable combustion. At a high load, the amount of air supplied from additional air holes or additional air nozzles 12 is reduced, whereby a flame is formed in a position far from the fuel nozzle 11. This suppresses thermal radiation onto a solid fuel burner 42 structure and a furnace 41 wall.

Abstract: According to a burner of the present invention, a stable combustion is obtained in a wide range from a high-load operation condition to a low-load operation condition even in the case of low quality solid fuel such as brown coal.

Abstract: A combustion method utilizing a pulverized coal combustion burner which is provided with a pulverized coal nozzle for jetting a fluid mixture of pulverized coal and air and an air nozzle for jetting air. In the method, a combustion flame formed by the pulverized coal combustion burner forms a first zone of a gas phase air ratio of one or less at a radially central portion of the flame and a second zone of a gas phase air ratio of more than one outside of the first zone adjacent the coal nozzle, and a third zone of a gas phase air ratio of one or less at a downstream side from said first and second zones.

Abstract: A pulverized coal burner includes a pulverized coal nozzle for jetting a mixture of pulverized coal and primary air, a secondary air nozzle and a tertiary air nozzle, concentrically arranged around the outer periphery of the pulverized coal nozzle, and a tube expanded portion at the end of a partition wall separating two adjacent air nozzles. A flow shift means such as a guide plate for shifting the secondary air in the secondary air nozzle so as to flow along the tube expanded portion is provided. The secondary air is jetted outwardly by the guide plate, and mixing of the secondary air and the tertiary air with pulverized coals is delayed, whereby an amount of NOx is decreased.

Abstract: A combustion apparatus including a mixture feeding pipe for injecting a mixture of pulverized coal for combustion air into a furnace, with the mixture being then ignited. A first gas feeding passage is disposed outwardly of the mixture feeding pipe for feeding oxygen-containing gas into the furnace, with a second gas feeding passage being disposed between the gas feeding passage and the mixture feeding pipe, in a radial direction, for feeding the oxygen-containing gas into the furnace. A projection is disposed between the gas feeding passage and the mixture feeding pipe and extends at an exposed end surface thereof into the furnace beyond an exposed end of the mixture feeding pipe, with the projection being hollow for allowing the oxygen-containing gas to flow within the projection.

Abstract: A combustion apparatus including a mixture feeding pipe for injecting a mixture of pulverized coal and combustion air into a furnace, with the mixture then being ignited. A radially outwardly flared flame maintaining ring is provided at a tip end of the mixture feeding pipe, with the maintaining ring being exposed to a reduced atmosphere and to high temperatures due to radiant heat from the furnace. A projection extends into the furnace beyond the flame maintaining ring so as to protect the flame maintaining ring from radiation from inside the furnace thereby suppressing an excessive increase in temperature. Combustion air flows along a surface of the projection so as to provide at oxidized atmosphere.