Hybrid atomizing fuel nozzle

An atomizing fuel nozzle for a fuel injector, comprising:

• a nozzle assembly including i) a pressure swirl atomizer portion providing fuel in a primary atomized spray;
• ii) an airblast nozzle portion radially outward surrounding the pressure swirl atomizer, said airblast nozzle portion providing fuel in a secondary atomized spray;
• and iii) a shroud and swirler assembly radially outward surrounding the airblast nozzle portion, the shroud and swirler assembly having an annular body with an internal prefilmer surface at a downstream end of the body, said body further including a radial inflow swirler at an upstream end of the prefilmer surface for directing a first swirling air flow radially inward toward a tip of the airblast nozzle portion, and an outer axial air swirler for directing a second swirling air flow in an axial and then a converging manner toward the central axis of the nozzle assembly downstream of the prefilmer surface;
• said airblast nozzle portion including at least one fuel passage with an orifice directing fuel radially-outward toward and against the prefilmer surface, the fuel being directed outwardly through the first air flow to cause the fuel to evenly distribute across the prefilmer surface in a thin and continuous sheet, the first and second air flows inwardly and outwardly bounding the sheet and causing the thin sheet to quickly atomize downstream of the prefilmer surface.

A fuel circuit subassembly for a hybrid atomizing fuel nozzle, the fuel circuit subassembly including:

• i) a pressure swirl atomizer portion providing fuel in a primary atomized spray;
• and ii) an airblast nozzle portion radially outward surrounding the pressure swirl atomizer portion, said airblast nozzle portion providing fuel in a secondary atomized spray;
• ii) said airblast nozzle portion including an annular main body with an inwardly angled downstream end, said angled downstream end having a plurality of fuel passages with orifices directing fuel in discrete streams radially-outward and downstream from the main body;
• and
• an annular heatshield surrounding the annular main body, and including an inwardly angled downstream end enclosing the inwardly angled downstream end of the annular main body, and having openings corresponding to the orifices of the fuel passages such that fuel can be dispensed in an uninterrupted manner from the fuel passages.

A gas turbine combustion assembly, including:

• a combustor chamber and a fuel injector supported within the combustion chamber, the combustor chamber directing pressurized air past the fuel injector to facilitate ignition of fuel, the fuel injector including:
• a nozzle stem including a primary fuel passage and a secondary fuel passage;
• a nozzle assembly fixed at a downstream end of the nozzle stem, said nozzle assembly including i) a primary nozzle portion in fluid communication with the primary fuel passage and providing fuel in a primary atomized spray;
• ii) a secondary nozzle portion radially outward surrounding the primary nozzle portion, said secondary nozzle portion in fluid communication with the secondary fuel passage and providing fuel in a secondary atomized spray;
• and
• iii) a shroud and swirler assembly, radially outward surrounding and fixed at the downstream end of the nozzle stem, said shroud and swirler assembly including an annular body with an internal prefilmer surface at a downstream end of the body, said body further including a radial inflow swirler at an upstream end of the prefilmer surface directing a first swirling air flow radially inward toward the secondary nozzle portion, and said shroud and swirler assembly further including an outer axial air swirler, the outer air swirler directing a second swirling air flow in an axial and then a converging manner downstream of the prefilmer surface;
• said secondary nozzle portion including at least one fuel passage with an orifice directing fuel in a stream radially-outward toward and against the prefilmer surface, the fuel stream being directed outwardly through the first swirling air flow to cause the fuel stream to swirl and evenly distribute across the prefilmer surface in a thin sheet, and the first and second swirling air flows inwardly and outwardly bounding the sheet and causing the thin sheet to then form a spray of atomized fuel downstream of the prefilmer surface.

A fuel injector, comprising:

• a nozzle stem including a fuel passage;
• a nozzle assembly fixed at a downstream end of the nozzle stem, said nozzle assembly including a nozzle portion in fluid communication with the fuel passage and providing fuel in an atomized spray;
• and
• a shroud and swirler assembly radially outward surrounding the nozzle portion, said shroud and swirler assembly including an annular body with a) an internal prefilmer surface at a downstream end of the body, and b) a radial inflow swirler at an upstream end of the prefilmer surface for directing a first swirling air flow radially inward toward the nozzle portion, and said shroud and swirler assembly also including an outer axial air swirler for directing a second swirling air flow in an axial and then a converging manner downstream of the prefilmer surface;
• said nozzle portion including at least one fuel passage with an orifice for directing fuel radially-outward toward and against the prefilmer surface, the fuel being directed outwardly through the first swirling air flow to cause the fuel to evenly distribute across the prefilmer surface in a thin and continuous sheet, the first and second swirling air flows inwardly and outwardly bounding the sheet and causing the sheet to quickly atomize downstream of the prefilmer surface.