Abstract: A biomass-mixed-firing pulverized coal fired boiler includes: a furnace for burning biomass fuel together with pulverized coal in a mixed state; a pulverized coal burner for supplying the pulverized coal into the furnace; a biomass burner for supplying the biomass fuel into the furnace; a biomass mill for milling the biomass fuel to be supplied to the biomass burner; a dry clinker processing unit provided below the furnace and including a clinker conveyor for carrying ashes discharged from the furnace at a furnace bottom; and a combustion-air supply unit for supplying combustion air toward the ashes discharged at the furnace bottom on the clinker conveyor, thereby to burn an unburned component of the biomass fuel contained in the ashes discharged at the furnace bottom on the clinker conveyor.

Abstract: A biomass-mixed-firing pulverized coal fired boiler includes: a furnace for burning biomass fuel together with pulverized coal in a mixed state; a pulverized coal burner for supplying the pulverized coal into the furnace; a biomass burner for supplying the biomass fuel into the furnace; a biomass mill for milling the biomass fuel to be supplied to the biomass burner; a dry clinker processing unit provided below the furnace and including a clinker conveyor for carrying ashes discharged from the furnace at a furnace bottom; and a combustion-air supply unit for supplying combustion air toward the ashes discharged at the furnace bottom on the clinker conveyor, thereby to burn an unburned component of the biomass fuel contained in the ashes discharged at the furnace bottom on the clinker conveyor.

Abstract: A boiler includes a coal pulverizer that pulverizes coal; a coal combustion unit that combusts gasified pulverized coal that has been pulverized by the coal pulverizer; a furnace that combusts gasified fuel generated by the coal combustion unit; a slag formation unit provided in an ash outlet of the coal combustion unit; means for supplying primary air, for supply of the pulverized coal; to the coal pulverizer; means for supplying secondary air, for gasified combustion, to the coal combustion unit; and means for supplying tertiary air, for gasified fuel combustion, to the furnace.

Abstract: A U-type slag-tap firing boiler includes a combustion furnace (5) formed in a volume so that a temperature of a gas flowing through a slag screen (4) separating the combustion furnace (5) and a radiant furnace (6) disposed below the combustion furnace (5) is maintained in a range that ensures the normal functioning of the slag screen (4) even if air is supplied through a burner (2) into the combustion furnace (5) at an air ratio below 1. NOx generation is reduced by decreasing air supply through the burner (2) into the combustion furnace (5) to below 1, burning pulverized coal in a fuel-rich combustion mode in the combustion furnace (5) to crate a reducing atmosphere therein, and heating the interior of the combustion furnace (5) at a temperature around fluid temperature.

Abstract: A method of combustion of pulverized coal in two stages of combustion to reduce the amount of NOx produced by combustion. In a first stage, exhaust gas is added to air for combustion in a proportion of 35-60% of the air necessary for carrying out combustion. In a second stage, air for combustion is supplied in a proportion of 25-35% of the air necessary for carrying out combustion. In this method of combustion, the pulverized coal is combusted slowly at low temperature with the formation of a flame of low brightness to produce in large amounts activated intermediate components responsible for denitration reaction to promote reduction of produced NOx, and the concentration of CO produced can be reduced by abstaining from using the minimum air necessary for combustion.

Abstract: A pulverized coal burner including a primary throat having at its forward end a swirler for feeding pulverized coal and primary air in vortical flow, a secondary throat located outside the primary throat for supplying secondary air and a burner throat located outside the secondary throat for supplying tertiary air, the secondary and burner throats being located concentrically with the primary throat having at its forward end a flame sustaining plate diverging outwardly to cause the secondary and tertiary air to flow away from the primary throat along the inner surface of the outwardly diverging forward end portion of the burner throat, to thereby avoid mixing of the secondary and tertiary air with the pulverized coal air in a primary flame region in which the pulverized coal burns slowly and produces NOx in reduced amount.