# US 12,601,491 B2 · Combustor having secondary fuel injector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,601,491 B2 - Document ID: US12601491B2 - Status: Granted - Kind: B2 - Application number: 18/868,810 - Filed: 2023-04-26 - Published: 2025-11-13 - Granted: 2026-04-14 - Earliest claimed: 2022-06-01 - Assignees: Siemens Energy Global GmbH & Co. KG - Applicants: Siemens Energy Global GmbH & Co. KG - Inventors: Landon Tully; Walter Ray Laster - Web page: https://patentgrep.com/patent/US12601491B2 ## CPC - F23R 3/06: Arrangement of apertures along the flame tube - F23R 3/34: Feeding into different combustion zones - F01D 9/023: {Transition ducts between combustor cans and first stage of the turbine in gas-turbine engines; their cooling or sealings} - F23R 3/14: by using swirl vanes - F23R 3/16: with devices inside the flame tube or the combustion chamber to influence the air or gas flow - F23R 3/286: {having fuel-air premixing devices (F23R3/30 takes precedence)} - F23R 3/346: {for staged combustion} - F23R 3/28: characterised by the fuel supply (burners F23D) - 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) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) ## Abstract A combustor includes a transition duct having a transition duct liner defining an opening that extends through the transition duct liner, a secondary fuel injector disposed in the opening. The secondary fuel injector has an inner shell arranged to define an inner space; an outer shell cooperating with the inner shell to define an outer space that is annular; a plurality of inner flow guides positioned within the inner space and arranged around the inner shell, each inner flow guide arranged to turn a first mixture of fuel and air in one of a clockwise and counterclockwise direction around the inner shell, a plurality of outer flow guides positioned within the outer space and arranged around the inner shell, each outer flow guide arranged to turn a second mixture of fuel and air in the other of the clockwise and counterclockwise direction around the inner shell. ## Claims ### Claim 1 A combustor comprising: a transition duct comprising a transition duct liner defining an opening that extends through the transition duct liner; and a secondary fuel injector disposed in the opening, the secondary fuel injector comprising: an inner shell arranged to define an inner space; an outer shell cooperating with the inner shell to define an outer space that is annular; a plurality of inner flow guides positioned within the inner space and arranged around the inner shell, each inner flow guide of the plurality of inner flow guides arranged to turn a first mixture of fuel and air in one of a clockwise and counterclockwise direction around the inner shell; and a plurality of outer flow guides positioned within the outer space and arranged around the inner shell, each outer flow guide of the plurality of outer flow guides arranged to turn a second mixture of fuel and air in the other of the clockwise and counterclockwise direction around the inner shell, wherein each inner flow guide of the plurality of inner flow guides comprises an airfoil shape having an inner flow guide pressure side wall and an inner flow guide suction side wall, and wherein the inner flow guide pressure side wall defines an inner flow guide fuel outlet. ### Claim 2 (depends on 1) The combustor of claim 1, wherein the secondary fuel injector comprises a plurality of inner vortex generators, and wherein one inner vortex generator of the plurality of inner vortex generators is attached to the inner flow guide suction side wall. ### Claim 3 (depends on 1) The combustor of claim 1, wherein each outer flow guide of the plurality of outer flow guides comprises an airfoil shape having an outer flow guide pressure side wall and an outer flow guide suction side wall. ### Claim 4 (depends on 3) The combustor of claim 3, wherein the outer flow guide pressure side wall defines an outer flow guide fuel outlet. ### Claim 5 (depends on 3) The combustor of claim 3, wherein the secondary fuel injector comprises a plurality of outer vortex generators, and wherein one outer vortex generator of the plurality of outer vortex generators is attached to the outer flow guide suction side wall. ### Claim 6 (depends on 1) The combustor of claim 1, wherein each inner flow guide of the plurality of inner flow guides has an inner span length, wherein each outer flow guide of the plurality of outer flow guides has an outer span length, and wherein the inner span length is less than the outer span length. ### Claim 7 (depends on 1) The combustor of claim 1, wherein the outer shell defines a hollow outer shell interior to provide the fuel to the plurality of outer flow guides. ### Claim 8 (depends on 1) The combustor of claim 1, wherein each inner flow guide of the plurality of inner flow guides is in flow connection with one outer flow guide of the plurality of outer flow guides. ### Claim 9 (depends on 1) The combustor of claim 1, wherein a quantity of the outer flow guides is more than a quantity of the inner flow guides. ### Claim 10 (depends on 1) The combustor of claim 1, wherein the secondary fuel injector comprises a central hub disposed at a center of the inner space, wherein the central hub comprises a radius that is between 10% to 90% of the inner shell, and wherein the plurality of the inner flow guides are positioned between the central hub and the inner shell. ### Claim 11 A combustor comprising: a transition duct comprising a transition duct liner defining an opening that extends through the transition duct liner; and a secondary fuel injector disposed in the opening, the secondary fuel injector comprising: an inner shell arranged to define an inner space; an outer shell cooperating with the inner shell to define an outer space that is annular; a plurality of inner flow guides positioned within the inner space and arranged around the inner shell, the plurality of inner flow guides arranged to turn a first mixture of fuel and air in one of a clockwise and counterclockwise direction around the inner shell, each inner flow guide of the plurality of inner flow guides comprising an airfoil shape having an inner flow guide pressure side wall and an inner flow guide suction side wall; and a plurality of outer flow guides positioned within the outer space and arranged around the inner shell, the plurality of outer airfoils arranged to turn a second mixture of fuel and air in the other of the clockwise and counterclockwise direction around the inner shell, each outer flow guide of the plurality of outer flow guides comprising an airfoil shape having an outer flow guide pressure side wall and an outer flow guide suction side wall, wherein the outer flow guide pressure side wall defines an outer flow guide fuel outlet. ### Claim 12 (depends on 11) The combustor of claim 11, wherein the inner flow guide pressure side wall defines an inner flow guide fuel outlet. ### Claim 13 (depends on 11) The combustor of claim 11, wherein the secondary fuel injector comprises a plurality of inner vortex generators, and wherein one inner vortex generator of the plurality of inner vortex generators is attached to the inner flow guide suction side wall. ### Claim 14 (depends on 11) The combustor of claim 11, wherein the secondary fuel injector comprises a plurality of outer vortex generators, and wherein one outer vortex generator of the plurality of outer vortex generators is attached to the outer flow guide suction side wall. ### Claim 15 (depends on 11) The combustor of claim 11, wherein each inner flow guide of the plurality of inner flow guides has an inner span length, wherein each outer flow guide of the plurality of outer flow guides has an outer span length, and wherein the inner span length is less than the outer span length. ### Claim 16 (depends on 11) The combustor of claim 11, wherein the outer shell defines a hollow outer shell interior to provide the fuel to the plurality of outer flow guides. ### Claim 17 (depends on 11) The combustor of claim 11, wherein each inner flow guide of the plurality of inner flow guides is in flow connection with one outer flow guide of the plurality of outer flow guides. ### Claim 18 A combustor comprising: a transition duct comprising a transition duct liner defining an opening that extends through the transition duct liner; and a secondary fuel injector disposed in the opening, the secondary fuel injector comprising: an inner shell arranged to define an inner space; an outer shell cooperating with the inner shell to define an outer space that is annular; a plurality of inner flow guides positioned within the inner space and arranged around the inner shell, each inner flow guide of the plurality of inner flow guides arranged to turn a first mixture of fuel and air in one of a clockwise and counterclockwise direction around the inner shell; and a plurality of outer flow guides positioned within the outer space and arranged around the inner shell, each outer flow guide of the plurality of outer flow guides arranged to turn a second mixture of fuel and air in the other of the clockwise and counterclockwise direction around the inner shell, wherein the outer shell defines a hollow outer shell interior to provide the fuel to the plurality of outer flow guides. ### Claim 19 A combustor comprising: a transition duct comprising a transition duct liner defining an opening that extends through the transition duct liner; and a secondary fuel injector disposed in the opening, the secondary fuel injector comprising: an inner shell arranged to define an inner space; an outer shell cooperating with the inner shell to define an outer space that is annular; a plurality of inner flow guides positioned within the inner space and arranged around the inner shell, each inner flow guide of the plurality of inner flow guides arranged to turn a first mixture of fuel and air in one of a clockwise and counterclockwise direction around the inner shell; and a plurality of outer flow guides positioned within the outer space and arranged around the inner shell, each outer flow guide of the plurality of outer flow guides arranged to turn a second mixture of fuel and air in the other of the clockwise and counterclockwise direction around the inner shell, wherein each inner flow guide of the plurality of inner flow guides is in flow connection with one outer flow guide of the plurality of outer flow guides.