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Show Refractory Quarl Figure 1: LNV™ Burner To meet more stringent N O x emissions requirements, flue gas recirculation (FGR) can be injected through FGR nozzles interlaced between the gas spuds or premixed with the combustion air depending on the retrofit application. Combustion air is injected through independently controlled primary or secondary air annuli with secondary air swirl control vanes that allow the flame shape to be optimized for specific furnace requirements. The oil gun and diffuser plate assembly position can be axially adjusted to optimize flame shape, stability and performance. EV BURNER DESIGN In the EV premixed burner, combustion air, flue gas, and natural gas are mixed prior to combustion. The flue gas acts as a thermal diluent to suppress the flame temperature which in-turn, minimizes N O x formation. The EV burner was originally developed for ABB gas turbines firing gaseous and liquid fuels. In this application, it achieves some of the lowest N O x emissions levels in the gas turbine industry1. The burner has an exceptionally simple design (Figure 2), consisting of two half-cones, offset to form two air inlet slots of constant width. The arrangement of the air inlet slots produces a strongly swirling flow field within and exiting the cones. The cone cluster arrangement maintains the dynamics of unique flow field with nominal burner capacity. Gaseous fuels are injected into the combustion air by means of fuel distribution tubes that contain rows of small holes along the inlet slot. Complete fuel and air mixing is 4 IV-24 |