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A fuel injector for a gas turbine engine is disclosed. The fuel injector includes an injector housing extending from a first end to a second end along a longitudinal axis. The second end of the housing is fluidly coupled to a combustor of the turbine engine and the housing includes a liquid fuel gal

A fuel injector for a gas turbine engine is disclosed. The fuel injector includes an injector housing extending from a first end to a second end along a longitudinal axis. The second end of the housing is fluidly coupled to a combustor of the turbine engine and the housing includes a liquid fuel gallery annularly disposed about the longitudinal axis. The fuel injector also includes a stem extending longitudinally from the first end of the housing to a third end. The stem includes a liquid tube configured to deliver liquid fuel to the fuel injector. The fuel injector also includes an annular shell extending along the longitudinal axis from the first end to the third end and circumferentially disposed about the stem. The fuel injector further includes an insulating air shroud formed inside the shell. The air shroud includes a layer of air between the shell and the stem.

대표청구항 ▼

1. A fuel injector for a gas turbine engine comprising: an injector housing extending from a third end to a first end along a longitudinal axis, the first end of the housing being fluidly coupled to a combustor of the turbine engine and configured to direct compressed air and a liquid fuel to the co

1. A fuel injector for a gas turbine engine comprising: an injector housing extending from a third end to a first end along a longitudinal axis, the first end of the housing being fluidly coupled to a combustor of the turbine engine and configured to direct compressed air and a liquid fuel to the combustor;a stem extending longitudinally form the third end of the housing in a direction away from the first end to a second end such that the third end is located between the second end and the first end, the stem including a liquid tube configured to deliver the liquid fuel to the fuel injector;an annular shell extending along the longitudinal axis from the third end to the second end and circumferentially disposed about the stem;an insulating air shroud formed inside the shell, the air shroud including a layer of atmospheric air formed in an annular space between the shell and the stem, the annular space (a) being closed at the third end to prevent flow of the atmospheric air in the air shroud to the combustor and (b) including one or more openings at the second end to vent the atmospheric air in the annular space to the atmosphere; anda covering member coupled to the shell and the stem at the second end to at least partially cover the annular space between the shell and the stem at the second end. 2. The fuel injector of claim 1, wherein the covering member is a substantially circular disk and the one or more openings are formed between the stem and the disk. 3. The fuel injector of claim 2, wherein the shell includes a flange at the second end, the flange extending radially outwards of the longitudinal axis. 4. The fuel injector or claim 3, wherein the flange includes a plurality of fastener holes arranged in circular array about the longitudinal axis, the flange being configured to couple to an outer casing of the turbine engine. 5. The fuel injector of claim 1, wherein the shell is configured to couple to an outer casing of the turbine engine to form a compressed air space in an area outside the shell, the compressed air space including the compressed air directed into the combustor through the fuel injector, and the shell substantially preventing a mixing of the compressed air in the compressed air space with the atmospheric air in the air shroud. 6. The fuel injector of claim 2, wherein only the one or more openings between the shell and the stem fluidly communicate the atmospheric air in the air shroud to the atmosphere. 7. The fuel injector of claim 1, wherein the shell has a generally tubular shape having a first diameter at the second end, a second diameter at the third end, and a third diameter between the second and third ends, the third diameter being smaller than the first diameter and the second diameter. 8. The fuel injector of claim 7, wherein a length of the shell between the third end and the second end is between about 9 inches (22.9 centimeters) to about 10 inches (25.4 centimeters). 9. The fuel injector of claim 7, wherein the first diameter is between about 3.5 inches (8.9 centimeters) to 4.5 inches (11.4 centimeters), the second diameter is between about 4 (10.2 centimeters) inches to about 5 inches (12.7 centimeters), and third diameter is between about 1.5 inches (3.8 centimeters) to about 2.5 inches (6.4 centimeters). 10. A method of assembling a fuel injector to a gas turbine engine comprising: fluidly coupling a first end of an injector housing to a combustor of the turbine engine, the housing extending from a third end to the first end along a longitudinal axis, the housing including a stem extending longitudinally form the third end in direction away from the first end to a second end such that the third end is located between the second end and the first end, the stem including a liquid tube configured to deliver a liquid fuel to the fuel injector;coupling an annular shell to the housing at the third end, the shell extending along the longitudinal axis from the third end to the second end and being circumferentially disposed about the stem to form an insulating air shroud in an annular space between the shell and the stem, the air shroud being a layer of atmospheric air in the annular space that is adapted to flow into and flow out of the annular space through one or more openings at the second end, the annular space being closed at the third end to prevent flow of the atmospheric air in the air shroud to the combustor; andcoupling the annular shell to an outer casing of the turbine engine to form a compressed air space, including compressed air, in an area outside the shell, the shell preventing a mixing of the compressed air in the compressed air space with the atmospheric air in the air shroud. 11. The method of claim 10 further including coupling a circular disk to the shell and the stem at the second end such that the one or more openings are formed between the stem and the disk to vent the atmospheric air in the air shroud to atmosphere. 12. The method of claim 10 further including connecting the liquid tube to a liquid fuel supply of the turbine engine. 13. A fuel injector for a gas turbine engine comprising: an injector housing extending from a third end to a first end along a longitudinal axis, the first end of the housing configured to be fluidly coupled to a combustor of the turbine engine;an air swirler positioned in the housing between the third end and the first end, the air swirler being configured to direct compressed air into the fuel injector;a stem extending longitudinally from the third end of the housing in a direction away from the first end to a second end such that the third end is located between the second end and the first end, the stem including a liquid tube configured to direct a liquid fuel to the combustor through the fuel injector;an annular shell circumferentially disposed about the stem, and extending from the third end to the second end, to separate an annular space within the shell from a compressed air space outside the shell, the compressed air space being adapted to include the compressed air that is configured to be directed into the fuel injector through the air swirler, and the annular space being configured to include atmospheric air, the annular shell being disposed about the stem such that the annular space is closed at the third end to prevent flow of the atmospheric air in the annular space to the combustor. 14. The fuel injector of claim 13, further including one or more openings that fluidly couple the annular space within the shell to the atmosphere. 15. The fuel injector of claim 14, further including a disk connected between the shell and the stem at the second end, the disk forming the one or more openings between the shell and the stem. 16. The fuel injector of claim 14, wherein the one or more openings are formed at the second end, and the atmospheric air in the annular space is configured to enter and exit the annular space only through the one or more openings. 17. The fuel injector of claim 13, wherein the liquid fuel tube is a first liquid fuel tube, and the stern further includes a second liquid fuel tube that is separate from the first liquid fuel tube. 18. The fuel injector of claim 13, wherein the annular shell is brazed to the housing at the third end. 19. The fuel injector of claim 13, wherein the annular shell is made of stainless steel.