# US 7,377,036 B2 · Methods for tuning fuel injection assemblies for a gas turbine fuel nozzle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,377,036 B2 - Document ID: US7377036B2 - Status: Granted - Kind: B2 - Application number: 10/957,575 - Filed: 2004-10-05 - Published: 2006-04-06 - Granted: 2008-05-27 - Earliest claimed: 2004-10-05 - Assignees: General Electric Company - Inventors: Jere A. Johnson; Mark J. Bailey; Mark D. Pezzutti; James Christopher Monaghan; Ron Souther; Robert R. Berry - Web page: https://patentgrep.com/patent/US7377036B2 ## CPC - F23R 3/286: {having fuel-air premixing devices (F23R3/30 takes precedence)} - F23D 2213/00: Burner manufacture specifications - F23R 2900/00016: Retrofitting in general, e.g. to respect new regulations on pollution - Y10T 29/49318: Repairing or disassembling - Y10T 29/49321: Assembling individual fluid flow interacting members, e.g., blades, vanes, buckets, on rotary support member - Y10T 29/49323: Assembling fluid flow directing devices, e.g., stators, diaphragms, nozzles - Y10T 29/49348: Burner, torch or metallurgical lance making - Y10T 29/49716: Converting - F23R: GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS (fluidised bed combustion apparatus specially adapted for operation at superatmospheric pressures F23C10/16) - F23D: BURNERS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A fuel nozzle assembly for a gas turbine includes a plurality of circumferentially spaced vanes with holes for flowing fuel from plenums within the vanes through holes in the vane walls for premixing with air. To tune the nozzle assembly, the holes are resized by reforming the existing holes to a predetermined hole size, securing plugs into the holes, and forming holes through at least certain of the plugs to diameters less than the diameter of the existing holes. ## Claims ### Claim 1 In a fuel nozzle assembly for a gas turbine having a plurality of circumferentially spaced vanes with holes through walls of the vanes for flowing fuel for premixing with air within the nozzle assembly, a method of tuning the fuel nozzle assembly by changing existing areas of the premix fuel holes in the vane walls comprising the steps of: (a) reforming the existing holes to predetermined areas different than the existing areas; (b) inserting plugs into the reformed holes of predetermined areas; (c) securing the plugs to the vane walls; and (d) forming holes through a selected number of the plugs to areas less than the predetermined areas of said plugs and different than the existing areas of the premix fuel holes. ### Claim 2 (depends on 1) A method according to claim 1 wherein the step of reforming includes electro-discharge machining the existing holes to larger areas than the existing areas of the fuel holes. ### Claim 3 (depends on 2) A method according to claim 2 including reaming the reformed holes to selected diameters. ### Claim 4 (depends on 1) A method according to claim 1 including performing steps (a)-(d) sequentially, prior to step (a), removing an inlet flow conditioner from about the nozzle assembly to obtain access to the nozzle assembly and subsequent to step (d), installing the removed or a new inlet flow conditioner about the nozzle assembly. ### Claim 5 (depends on 1) A method according to claim 1 wherein the existing holes include a pair of holes in a first wall of each vane and at least one hole in a second wall of each vane opposite said first wall, and step (a) includes reforming the holes in the first wall by enlarging the areas of said pair of holes and forming a second pair of holes through said second wall with one of said holes of said second pair thereof having a larger area than and taking the place of the area of said at least one hole of said second wall. ### Claim 6 (depends on 5) A method according to claim 5 including forming the holes of each pair thereof to a common area. ### Claim 7 (depends on 5) A method according to claim 5 including forming holes through a pair of said plugs in said first wall and forming a hole through one of said plugs in said second wall, leaving said second plug in said second wall without a hole. ### Claim 8 (depends on 1) A method according to claim 1 wherein step (c) includes brazing the plugs to the walls of the vanes. ### Claim 9 (depends on 8) A method according to claim 8 wherein step (c) includes twice brazing the plugs to the vanes and performing a leak test between the two brazing steps. ### Claim 10 (depends on 1) A method according to claim 1 wherein step (d) is performed by electro-discharge machining. ### Claim 11 In a fuel nozzle assembly for a gas turbine having a plurality of circumferentially spaced vanes with holes through walls of the vanes for flowing fuel for premixing with air within the nozzle assembly, a method of tuning the fuel nozzle assembly by changing the diameter of the premix fuel holes in the vane walls comprising the steps of: (a) reforming the existing holes to a predetermined areas different than the existing diameter; (b) inserting plugs into the reformed holes of predetermined areas; (c) securing the plugs to the vane walls; and (d) forming holes through a selected number of the plugs to diameters less than the diameters of said existing holes. ### Claim 12 (depends on 11) A method according to claim 11 wherein the step of reforming includes electro-discharge machining the existing holes to larger diameters. ### Claim 13 (depends on 12) A method according to claim 12 including reaming the reformed holes to selected diameters. ### Claim 14 (depends on 11) A method according to claim 11 including performing steps (a)-(d) sequentially, prior to step (a), removing an inlet flow conditioner from about the nozzle assembly to obtain access to the nozzle assembly and subsequent to step (d), installing the removed or a new inlet flow conditioner about the nozzle assembly. ### Claim 15 (depends on 11) A method according to claim 11 wherein the existing holes include a pair of holes in a first wall of each vane and at least one hole in a second wall of each vane opposite said first wall, and step (a) includes reforming the holes in the first wall by enlarging the diameters of said pair of holes and forming a second pair of holes through said second wall with one of said holes of said second pair thereof being larger than and taking the place of said at least one hole of said second wall. ### Claim 16 (depends on 15) A method according to claim 15 including forming the holes of each pair thereof to a common diameter. ### Claim 17 (depends on 15) A method according to claim 15 including forming holes through a pair of said plugs in said first wall and forming a hole through one of said plugs in said second wall, leaving said second plug in said second wall without a hole. ### Claim 18 (depends on 11) A method according to claim 11 wherein step (c) includes brazing the plugs to the walls of the vanes. ### Claim 19 (depends on 18) A method according to claim 18 wherein step (c) includes twice brazing the plugs to the vanes and performing a leak test between the two brazing steps. ### Claim 20 (depends on 11) A method according to claim 11 wherein step (d) is performed by electro-discharge machining.