Abstract: In a nozzle for feeding a combustible medium such as coal particles along with air into a furnace, the exit end of each splitter plate in the nozzle is reinforced by a stiffener having an external cross-sectional shape in the form of a continuous curve proceeding outward and forward from a first surface of the plate to a first location, inward from the first location to a second location beyond the level of an opposite second surface of the plate, and inward and rearward from the second location to the second surface. The stiffener can be hollow, and can also be provided with openings for the flow of cooling air from the interior to the exterior of the stiffener. The continuous curvature of the exterior of the stiffener avoids recirculating flow at locations adjacent the stiffener and thereby minimizes flame attachment and deposition of ash or fuel sediment onto the reinforced splitter plates.

Abstract: In a nozzle for feeding a combustible medium such as coal particles along with air into a furnace, the exit end of each splitter plate in the nozzle is reinforced by a stiffener having an external cross-sectional shape in the form of a continuous curve proceeding outward and forward from a first surface of the plate to a first location, inward from the first location to a second location beyond the level of an opposite second surface of the plate, and inward and rearward from the second location to the second surface. The stiffener can be hollow, and can also be provided with openings for the flow of cooling air from the interior to the exterior of the stiffener. The continuous curvature of the exterior of the stiffener avoids recirculating flow at locations adjacent the stiffener and thereby minimizes flame attachment and deposition of ash or fuel sediment onto the reinforced splitter plates.

Abstract: In a boiler furnace having nozzles for introducing combustion media such as air and coal, nozzle tip walls that have the greatest exposure to radiant heat and hot gases are provided with arrays of air holes that allow air to flow to the exposed sides of the walls from the opposite sides in order to reduce the temperature difference between the two sides and thereby reduce thermal distortion and damage resulting from oxidation.

Abstract: In a boiler furnace having nozzles for introducing combustion media such as air and coal, nozzle tip walls that have the greatest exposure to radiant heat and hot gases are provided with arrays of air holes that allow air to flow to the exposed sides of the walls from the opposite sides in order to reduce the temperature difference between the two sides and thereby reduce thermal distortion and damage resulting from oxidation.

Abstract: A nozzle for feeding combustion maintaining medium into a furnace at high temperature conditions includes a nozzle tip, at least partly protruding into the furnace, and a feeding mechanism for feeding the combustion medium from a source of the medium to the nozzle tip. The nozzle tip includes a mainly open ended outer shell, an air cooling zone, a shroud, and an air channel. The outer shell includes a first end wall portion in flow connection with the feeding mechanism and a second end wall portion protruding into the furnace. The cooling zone is formed on the interior side of at least a portion of the second end wall portion of the outer shell, by providing an air flow along the interior side. The shroud includes a shroud wall portion disposed to cover at least a portion of the first end wall portion of the outer shell.

Abstract: A clustered concentric tangential firing system (12) particularly suited for use in fossil fuel-fired furnaces (10) and a method of operating such furnaces (10) equipped with a clustered concentric tangential firing system (12).

Abstract: An improved nozzle tip (30) which provides enhanced ignition and stabilization of pulverized fuel flames in furnaces operating at low load. The nozzle tip (30) comprises open-ended inner and outer shells (32,34) mounted to the fuel delivery pipe (12) and defining a flow passageway within the inner shell through which the pulverized fuel is directed into the furnace and an annular flow passageway (50) between the inner and outer shells through which additional air is directed into the furnace. A pair of diverging splitter plates (41,42) are disposed within the inner shell (32) so as to divide the flow passageway therethrough into two separate, diverging subpassages (52,54) so that the pulverized fuel stream discharging from the fuel delivery pipe is split into first and second streams (60,70) which pass from the nozzle tip (30) into the furnace in a diverging manner thereby establishing an ignition stabilizing pocket in the low pressure zone (80) created between the diverging fuel streams.