High reliability fuel oil nozzle for a gas turbine

Claim 2

A fuel nozzle for a gas turbine comprising: (a) elongate, coaxial inner and outer tubes, the outer tube being telescoped over the inner tube to define an obstructed annular air flow passageway therebetween, the inner tube defining an unobstructed fuel flow passageway, each tube having distal and proximal ends; (b) a body having air and fuel inlets communicating with the air flow and fuel flow passageways, respectively, the proximal end of each tube being within the body, the inner tube being rigidly fixed to the body, the outer tube being axially movable between the inner tube and the body; (c) a nozzle tip disposed on the distal end of the inner tube and having a frustoconical outer surface and a central orifice communicating with the fuel passageway for ejection of fuel, and a swirl cap with a conical aperture disposed on the distal end of the outer tube in coaxial alignment with the orifice of the nozzle tip, the swirl cap including a plurality of air passages communicating with the air passageway for directing air into a stream of ejected fuel; and, (d) spring means disposed in a cavity of the body for urging the outer tube in the direction of the body and biasing sides of the conical aperture in the swirl cap into airtight contact with the outer surface of the nozzle tip while permitting differential expansion between the outer and inner tubes, the spring means being located radially outward of the outer tube and out of the air flow and fuel flow fuel passages.

Claim 3

Nozzle according to claim 1 further comprising a lip disposed on the proximal end of the outer tube and within the body and the spring means urges against the lip.

Claim 4

Nozzle according to claim 1 further comprising a lip disposed on the proximal end of the outer tube and within the body and a preload ring annularly disposed around the outer tube and at least partially disposed within the cavity, the spring means comprising a conical spring having a radially innermost end bearing on the lip and a radially outermost end bearing on the preload ring.

Claim 5

Nozzle according to claim 3 wherein bolts extends through the body for mounting in a combustor.

Claim 6

Nozzle according to claim 1 further comprising a lip disposed on the proximal end of the outer tube and within the body, the body being bolted to a combustor plate having a surface covering the cavity, the spring means comprising a plurality of coil springs seated in indentations in the lip and bearing against the combustor plate surface and lip.

Claim 7

Nozzle according to claim 5 further comprising an annular packing ring disposed between the lip and the body for providing a seal between the outer tube and the body.

Claim 8

Nozzle according to claim 1 wherein the nozzle tip is demountably attached to the distal end of the inner tube.

Claim 9

Nozzle according to claim 1 wherein the swirl cap is demountably attached to the distal end of the outer tube.

Claim 10

Method of manufacturing a fuel nozzle for a gas turbine comprising the steps of: (a) providing elongate inner and outer tubes each having distal and proximal ends, the inner tube having an outside diameter smaller than an outside diameter of the outer tube, the inner tube being rigidly fixed at its proximal end to a body, the body having a cavity and air and fuel inlets, the outer tube having a lip at its proximal end; (b) providing a nozzle tip having a frustoconical outer surface and a swirl cap having a conical aperture; (c) providing a preload ring and a conical spring; (d) threadedly mounting the nozzle tip to the distal end of the inner tube and threadedly mounting the swirl cap to the distal end of the outer tube; (e) telescoping the outer tube over the inner tube so that sides of the conical aperture contact the outer surface of the nozzle tip and the lip extends into the cavity, an unobstructed annular passageway being defined between the inner and outer tubes and a separate unobstructed fuel flow passageway being defined by the inner tube, the air inlet communicating with the annular passageway and the fuel inlet communicating with the inner tube; (f) sliding the conical spring over the outer tube and into the cavity so that a radial innermost surface thereof contacts the lip; (g) sliding the preload ring over the outer tube so that it contacts a radial outermost surface of the conical spring and urges the outer tube in the direction of the body and biases sides of the conical aperture in the swirl cap into airtight contact with the outer surface of the nozzle tip while permitting differential expansion between the outer and inner tubes; and, (h) engaging the preload ring to maintain juxtaposition of the outer tube, conical spring, preload ring and cavity while permitting axial movement of the outer tube between the inner tube and body.

Claim 11

Method of manufacturing a fuel nozzle for a gas turbine comprising the steps of: (a) providing elongate inner and outer tubes each having distal and proximal ends, the inner tube having an outside diameter smaller than an outside diameter of the outer tube, the inner tube being rigidly fixed at its proximal end to a body, the body having a cavity and air and fuel inlets, the outer tube having a lip at its proximal end; (b) providing a nozzle tip having a frustoconical outer surface and a swirl cap having a conical aperture; (c) providing a preload ring and a conical spring; (d) threadedly mounting the nozzle tip to the distal end of the inner tube and threadedly mounting the swirl cap to the distal end of the outer tube; (e) telescoping the outer tube over the inner tube so that sides of the conical aperture contact the outer surface of the nozzle tip and the lip extends into the cavity, an unobstructed annular passageway being defined between the inner and outer tubes and a separate unobstructed fuel flow passageway being defined by the inner tube, the air inlet communicating with the annular passageway and the fuel inlet communicating with the inner tube; (f) sliding the conical spring over the outer tube and into the cavity so that a radial innermost surface thereof contacts the lip; (g) sliding the preload ring over the outer tube so that it contacts a radial outermost surface of the conical spring and urges the outer tube in the direction of the body and biases sides of the conical aperture in the swirl cap into airtight contact with the outer surface of the nozzle tip while permitting differential expansion between the outer and inner tubes; and, (h) engaging the preload ring to maintain juxtaposition of the outer tube, conical spring, preload ring and cavity while permitting axial movement of the outer tube between the inner tube and body.

Claim 12

Method according to claim 9 wherein the nozzle is disassembled for cleaning by: (a) removing the preload ring; and (b) telescopically removing the outer tube and exposing the the inner tube.

Claim 13

Method of manufacturing a fuel nozzle for a gas turbine comprising the steps of: (a) providing elongate inner and outer tubes each having distal and proximal ends, the inner tube having an outside diameter smaller than an outside diameter of the outer tube, the inner tube being rigidly fixed at its proximal end to a body, the body having a cavity and air and fuel inlets, the outer tube having a lip at its proximal end, the lip having indentations therearound; (b) providing a nozzle tip having a frustoconical outer surface and a swirl cap having a conical aperture; (c) providing a plurality of coil springs; (d) threadedly mounting the nozzle tip to the distal end of the inner tube and threadedly mounting the swirl cap to the distal end of the outer tube; (e) telescoping the outer tube over the inner tube so that sides of the conical aperture contact the outer surface of the nozzle tip and the lip extends into the cavity, an unobstructed annular passageway being defined between the inner and outer tubes and a separate unobstructed fuel flow passageway being defined by the inner tube, the air inlet communicating with the annular passageway and the fuel inlet communicating with the inner tube; (f) placing each of the plurality of springs in an indentation in the lip; (g) mounting the nozzle to a combustor plate so that the combustor plate covers the cavity and compresses the springs, the springs bearing against the lip and the combustor plate and urging the outer tube in the direction of the body and biasing sides of the conical aperture in the swirl cap into airtight contact with the outer surface of the nozzle tip while permitting differential expansion between the outer and inner tubes, the outer tube being axially movable between the inner tube and body.

Claim 14

Method of manufacturing a fuel nozzle for a gas turbine comprising the steps of: (a) providing elongate inner and outer tubes each having distal and proximal ends, the inner tube having an outside diameter smaller than an outside diameter of the outer tube, the inner tube being rigidly fixed at its proximal end to a body, the body having a cavity and air and fuel inlets, the outer tube having a lip at its proximal end, the lip having indentations therearound; (b) providing a nozzle tip having a frustoconical outer surface and a swirl cap having a conical aperture; (c) providing a plurality of coil springs; (d) threadedly mounting the nozzle tip to the distal end of the inner tube and threadedly mounting the swirl cap to the distal end of the outer tube; (e) telescoping the outer tube over the inner tube so that sides of the conical aperture contact the outer surface of the nozzle tip and the lip extends into the cavity, an unobstructed annular passageway being defined between the inner and outer tubes and a separate unobstructed fuel flow passageway being defined by the inner tube, the air inlet communicating with the annular passageway and the fuel inlet communicating with the inner tube; (f) placing each of the plurality of springs in an indentation in the lip; (g) mounting the nozzle to a combustor plate so that the combustor plate covers the cavity and compresses the springs, the springs bearing against the lip and the combustor plate and urging the outer tube in the direction of the body and biasing sides of the conical aperture in the swirl cap into airtight contact with the outer surface of the nozzle tip while permitting differential expansion between the outer and inner tubes, the outer tube being axially movable between the inner tube and body.

Claim 15

Method according to claim 11 wherein the nozzle is disassembled for cleaning by: (a) dismounting the nozzle from the combustor plate; and, (b) telescopically removing the outer tube and exposing the the inner tube.