# US 8,899,494 B2 · Bi-directional fuel injection method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,899,494 B2 - Document ID: US8899494B2 - Status: Granted - Kind: B2 - Application number: 13/077,719 - Filed: 2011-03-31 - Published: 2012-10-04 - Granted: 2014-12-02 - Earliest claimed: 2011-03-31 - Assignees: General Electric Company - Applicants: Ronald Scott Bunker; Andrei Tristan Evulet - Inventors: Ronald Scott Bunker; Andrei Tristan Evulet - Web page: https://patentgrep.com/patent/US8899494B2 ## CPC - F23R 3/30: comprising fuel prevapourising devices - F23R 3/14: by using swirl vanes - F23R 3/286: {having fuel-air premixing devices (F23R3/30 takes precedence)} - F23C 2900/07001: Air swirling vanes incorporating fuel injectors - F23D 2209/10: Flame flashback - F23R 2900/00014: Reducing thermo-acoustic vibrations by passive means, e.g. by Helmholtz resonators - F23R 2900/03281: Intermittent fuel injection or supply with plunger pump or other means therefor - 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) - F23C: METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN {A CARRIER GAS OR} AIR (burners F23D) - F23D: BURNERS ## Abstract In certain embodiments, a fuel injector includes a wall separating a fuel passage from an air passage. The fuel injector also includes a fuel injection port extending from a first side of the wall to a second side of the wall for injecting a flow of fuel from the fuel passage into a flow of air in the air passage. In addition, the fuel injector includes first and second feedback lines extending from a downstream end of the fuel injection port to an upstream end of the fuel injection port. The first and second feedback lines are disposed on opposite sides of the fuel injection port. In addition, the first and second feedback lines are disposed entirely within the wall. ## Claims ### Claim 1 A fuel nozzle, comprising: a fuel passage through which a fuel flows; an air passage through which air flows; and a wall separating the fuel passage from the air passage, wherein the wall comprises: at least one fuel injection port extending from a first side of the wall to a second side of the wall for injecting the flow of fuel into the flow of air; and first and second feedback lines extending from a downstream end of the fuel injection port to an upstream end of the fuel injection port, wherein the first and second feedback lines are disposed on opposite sides of the fuel injection port, and wherein the first and second feedback lines are disposed entirely within the wall, wherein the first and second feedback lines are configured to passively induce feedback flows of fuel through the first and second feedback lines in an alternating manner such that the flow of fuel through the fuel injection port oscillates from side to side of the fuel injection port. ### Claim 2 (depends on 1) The fuel nozzle of claim 1, wherein a cross-sectional area of the fuel injection port increases from the upstream end to the downstream end. ### Claim 3 (depends on 1) The fuel nozzle of claim 1, wherein the first and second feedback lines each comprise first and second ends that are substantially orthogonal to a central axis of the flow of fuel, wherein the first end is proximate to the downstream end of the fuel injection port and the second end is proximate to the upstream end of the fuel injection port. ### Claim 4 (depends on 3) The fuel nozzle of claim 3, wherein the first and second feedback lines comprise only substantially orthogonal sections from the first end to the second end. ### Claim 5 (depends on 3) The fuel nozzle of claim 3, wherein the first and second feedback lines comprise rounded sections from the first end to the second end. ### Claim 6 (depends on 1) The fuel nozzle of claim 1, wherein cross-sectional areas of the first and second feedback lines are sized based upon an expected fuel flow rate through the fuel injection port. ### Claim 7 (depends on 1) The fuel nozzle of claim 1, wherein lengths of the first and second feedback lines are sized based upon an expected fuel flow rate through the fuel injection port. ### Claim 8 (depends on 1) The fuel nozzle of claim 1, wherein the wall comprises a plurality of fuel injection ports, and wherein cross-sectional areas of the first and second feedback lines associated with the fuel injection ports vary between fuel injection ports. ### Claim 9 (depends on 1) The fuel nozzle of claim 1, wherein the wall comprises a plurality of fuel injection ports, and wherein lengths of the first and second feedback lines associated with the fuel injection ports vary between fuel injection ports. ### Claim 10 (depends on 1) The fuel nozzle of claim 1, wherein a central axis of the flow of fuel through the fuel injection port is angled with respect to the wall. ### Claim 11 A fuel injector, comprising: a wall separating a fuel passage from an air passage; a fuel injection port extending from a first side of the wall to a second side of the wall for injecting a flow of fuel from the fuel passage into a flow of air in the air passage; and first and second feedback lines extending from a downstream end of the fuel injection port to an upstream end of the fuel injection port, wherein the first and second feedback lines are disposed on opposite sides of the fuel injection port, and wherein the first and second feedback lines are disposed entirely within the wall, wherein the first and second feedback lines are configured to passively induce feedback flows of fuel through the first and second feedback lines in an alternating manner such that the flow of fuel through the fuel injection port oscillates from side to side of the fuel injection port. ### Claim 12 (depends on 11) The fuel injector of claim 11, wherein the first and second feedback lines each comprise first and second ends that are substantially orthogonal to a central axis of the flow of fuel, wherein the first end is proximate to the downstream end of the fuel injection port and the second end is proximate to the upstream end of the fuel injection port. ### Claim 13 (depends on 11) The fuel injector of claim 11, wherein the wall comprises a plurality of fuel injection ports, and wherein cross-sectional areas or lengths of the first and second feedback lines associated with the fuel injection ports vary between fuel injection ports. ### Claim 14 (depends on 11) The fuel injector of claim 11, wherein the cross-sectional area of the fuel injection port increases from the upstream end to the downstream end, and wherein a central axis of the flow of fuel through the fuel injection port is angled with respect to the wall. ### Claim 15 A fuel injector, comprising: a wall separating a fuel passage from an air passage; a fuel injection port extending from a first side of the wall to a second side of the wall for injecting a flow of fuel from the fuel passage into a flow of air in the air passage; and first and second feedback lines extending from a downstream end of the fuel injection port to an upstream end of the fuel injection port, wherein the first and second feedback lines are disposed on opposite sides of the fuel injection port, and wherein the first and second feedback lines are disposed entirely within the wall, wherein the first and second feedback lines each comprise first and second ends that are substantially orthogonal to a central axis of the flow of fuel, wherein the first end is proximate to the downstream end of the fuel injection port and the second end is proximate to the upstream end of the fuel injection port. ### Claim 16 A fuel injector, comprising: a wall separating a fuel passage from an air passage; a fuel injection port extending from a first side of the wall to a second side of the wall for injecting a flow of fuel from the fuel passage into a flow of air in the air passage; and first and second feedback lines extending from a downstream end of the fuel injection port to an upstream end of the fuel injection port, wherein the first and second feedback lines are disposed on opposite sides of the fuel injection port, and wherein the first and second feedback lines are disposed entirely within the wall, wherein the cross-sectional area of the fuel injection port increases from the upstream end to the downstream end, and wherein a central axis of the flow of fuel through the fuel injection port is angled with respect to the wall.