Abstract: To provide a burner structure that is capable of efficiently cooling a nozzle main body with a small amount of air, and takes an efficient countermeasure against a falling clinker or radiation heat. The burner structure includes: a pulverized coal-air mixture path provided in a burner central portion and supplying a mixture of a fuel and a primary air; a secondary air path provided around the pulverized coal-air mixture path and supplying a secondary air; a cooling air path provided around or above and below the secondary air path and supplying a cooling air; a nozzle main body attached to furnace-side end portions of the pulverized coal-air mixture path and the secondary air path in a tiltable form and provided with a flame holder at its tip end; and a cooling air nozzle attached to a furnace-side end portion of the cooling air path in a tiltable form.

Abstract: To provide a burner structure that is capable of efficiently cooling a nozzle main body with a small amount of air, and takes an efficient countermeasure against a falling clinker or radiation heat. The burner structure includes: a pulverized coal-air mixture path provided in a burner central portion and supplying a mixture of a fuel and a primary air; a secondary air path provided around the pulverized coal-air mixture path and supplying a secondary air; a cooling air path provided around or above and below the secondary air path and supplying a cooling air; a nozzle main body attached to furnace-side end portions of the pulverized coal-air mixture path and the secondary air path in a tiltable form and provided with a flame holder at its tip end; and a cooling air nozzle attached to a furnace-side end portion of the cooling air path in a tiltable form.

Abstract: To provide a low combustibility fuel firing burner that can ensure high ignition performance and combustion stability even if a gas flow rate is changed along with changes in boiler load or the like. A low combustibility fuel firing burner separates a pulverized low combustibility fuel supplied together with an air with a separator, distributing the separated fuel to a rich portion nozzle and a lean portion nozzle provided in a furnace, and burning the fuel, in which a variable control part such as a core or a flow adjusting/blocking valve is provided in at least one of a high-particle-concentration gas pipe extending from a downstream side of the separator and communicating with the rich portion nozzle and a low-particle-concentration gas pipe extending from the downstream side of the separator and communicating with the lean portion nozzle.