Abstract: To minimize NO.sub.x emissions in an intermediate size industrial boiler furnace having two vertically spaced rows of burners, each upper burner has a central fuel nozzle and a main air opening adjacent to the nozzle and communicating with a wind box associated with the furnace. In addition, each upper burner has a plurality of air delivery ports through the wall surrounding said upper burner, such air delivery ports also communicating with the wind box. The air delivery ports can be of different sizes and shapes and can be at different angles with respect to the vertical plane of the wall through which the air delivery ports extend. Control of the air through the main air opening adjacent to the nozzle of each upper burner is achieved by one or more shiftable registers or dampers which operate to close the air flow from the wind box to the air opening.

Abstract: A staged, high efficiency burner for gaseous, liquid or pulverized solid fuels (including fuels having a high nitrogen content) in which NOX emissions are minimized. The burner includes a burner basket having a base including a throat and a concentric, tubular, frustroconically shaped wall that defines a primary combustion space. The fuel and primary air of about 75% of stoichiometric air are introduced into the basket which has a length so that the fuel has a residence time therein of between about 0.1 to 0.5 second. Secondary air is introduced into the flame downstream of the basket in the form of a multiplicity of individual air streams which are oriented to penetrate the flame and spin it about its axis so as to maintain a substantially cylindrical flame periphery.

Abstract: A burner which has a central liquid fuel atomizing nozzle is disclosed. An inner member defines a steam chamber and is surrounded by a shell that defines a liquid fuel compartment. A conduit extends from the steam chamber forming a steam core flow. A first passage feeds liquid fuel about the steam core flow to form an annular liquid fuel stream thereabout. A second passage forms an outer steam flow which envelops the annular liquid fuel flow. The burner further includes ducts to form a first combustion airflow co-axially about the nozzle, a second combustion airflow which surrounds the first flow, and a third combustion airflow which envelops the second flow and generally protects the furnace wall from coming into contact with the flame generated by the burner.

Abstract: A flame forming burner for simultaneously minimizing excess air consumption while suppressing NO.sub.x emissions. A dual zone air register is provided to supply primary air in substoichiometric quantity into mixture with fuel to produce a flame in a primary zone. Additional air is introduced around the flame and downstream of the initial combustion site in a secondary zone, in sufficient quantity to complete combustion. In the preferred embodiment, primary air is provided through a venturi throat, and secondary air is provided through an annular passage equipped with vanes which generate dual counter-rotating (DCR) air flow surrounding the primary zone. Dampers for each register control the primary to secondary air ratio. Preferably, a divergent, non-circular throat provides flame shaping.

Abstract: An oil fired burner adapted to produce a variable asymmetrical flame shape. The burner includes a tip head carrying a plurality of tips disposed in at least two orientations, i.e., axial and off-axis. The relative rates of fuel supply to the tips is controlled to afford asymmetric flame shaping. In a typical application in a rotary cement kiln, the flame is biased to increase the heat transferred to the load in the front end of the kiln and to decrease the heat transferred to the top and sides of the kiln.

Abstract: An integrated method is disclosed for preparing and suspension firing of bagasse and the like as the primary fuel for steam power generation in a cane sugar refinery. The method comprises mixing wet bagasse with de-ashed hot flue gases of a steam boiler, thereby drying it; separating bagasse dried thereby from the drying flue gases, capturing substantially all suspended dust; sizing the dried bagasse; directing bagasse fines to temporary storage while grinding and resizing any oversize bagasse; metering out and pneumatically suspending the fines, providing a smooth-flowing fuel responsive to a burner fuel feed control means; combusting the suspended fuel in a scroll feed type burner firing the steam boiler; de-ashing the combustion effluent, and utilizing the resultant flue gases for drying wet bagasse. Alternatively, the wet bagasse may be dried partially by de-ashed hot flue gases and partially by a bagasse fired supplementary hot air dryer, thereby further improving boiler operation efficiency.