# US 2023/0266012 A1 · Mixer assembly with a catalytic metal coating for a gas turbine engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0266012 A1 - Document ID: US20230266012A1 - Status: Published application - Kind: A1 - Application number: 17/651,685 - Filed: 2022-02-18 - Published: 2023-08-24 - Earliest claimed: 2022-02-18 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: Lawrence B. Kool; Bernard P. Bewlay; Byron A. Pritchard; Ramal Janith Samarasinghe; Michael A. Benjamin; Lakshmi Krishnan; Hrishikesh Keshavan - Web page: https://patentgrep.com/patent/US20230266012A1 ## CPC - F02C 7/30: Preventing corrosion {or unwanted deposits} in gas-swept spaces - F23R 3/286: {having fuel-air premixing devices (F23R3/30 takes precedence)} - F23R 3/343: {Pilot flames, i.e. fuel nozzles or injectors using only a very small proportion of the total fuel to insure continuous combustion (ignition in gas-turbine plants F02C7/264; pilot flame igniters F23Q9/00)} - F23R 3/40: characterised by the use of catalytic means - F23R 3/14: by using swirl vanes - F23R 2900/00004: Preventing formation of deposits on surfaces of gas turbine components, e.g. coke deposits - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - 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) ## Abstract A mixer assembly for a gas turbine engine. The mixer assembly includes a housing and a fuel injection port. The housing has a passage formed therein, and the housing includes a passage wall facing the passage. The fuel injection port is fluidly connected to a fuel source and is configured to inject a hydrocarbon fuel into the passage. At least a portion of the passage wall is a coated passage wall. The coated passage wall is (i) coated with a layer of a catalytic metal and (ii) located downstream of the fuel injection port. ## Claims ### Claim 1 A mixer assembly for a gas turbine engine, the mixer assembly comprising: a housing including a passage formed therein and a passage wall facing the passage; and a fuel injection port fluidly connected to a fuel source and configured to inject a hydrocarbon fuel into the passage, wherein at least a portion of the passage wall is a coated passage wall, the coated passage wall being (i) coated with a layer of a catalytic metal and (ii) located downstream of the fuel injection port. ### Claim 2 (depends on 1) The mixer assembly of claim 1, wherein the layer of the catalytic metal of the coated passage wall has a surface roughness, the surface roughness being from twenty microinches to one hundred fifty microinches. ### Claim 3 (depends on 1) The mixer assembly of claim 1, wherein the catalytic metal is a metal selected from the group consisting of ruthenium, rhodium, palladium, osmium, iridium, and platinum. ### Claim 4 (depends on 1) The mixer assembly of claim 1, wherein the catalytic metal is one of palladium, platinum, or gold. ### Claim 5 (depends on 1) The mixer assembly of claim 1, wherein the layer of the catalytic metal has a thickness that is less than twenty-five microns. ### Claim 6 (depends on 1) The mixer assembly of claim 1, wherein the layer of the catalytic metal has a thickness that is from five microns to ten microns. ### Claim 7 (depends on 1) The mixer assembly of claim 1, wherein the layer of the catalytic metal is an electroplated layer. ### Claim 8 (depends on 1) The mixer assembly of claim 1, wherein the passage wall is formed from a metal alloy chosen from the group consisting of iron-based alloys, nickel-based alloys, and chromium-based alloys. ### Claim 9 (depends on 1) The mixer assembly of claim 1, wherein the passage includes a conical section, a passage wall of the conical section of the passage being the coated passage wall. ### Claim 10 (depends on 9) The mixer assembly of claim 9, wherein the conical section has an upstream end and a downstream end, the passage having a cross-sectional area at each of the upstream end and the downstream end, the cross-sectional area of the passage at the downstream end of the conical section being greater than the cross-sectional area of the passage at the upstream end of the conical section. ### Claim 11 (depends on 1) The mixer assembly of claim 1, further comprising an air inlet configured to introduce air to flow through the air inlet into the passage, the air inlet being upstream of the coated passage wall. ### Claim 12 (depends on 11) The mixer assembly of claim 11, wherein the passage is a venturi including a converging section, a diverging section, and a throat, the coated passage wall including the passage wall of the diverging section. ### Claim 13 (depends on 12) The mixer assembly of claim 12, wherein the coated passage wall further includes the passage wall of the converging section. ### Claim 14 (depends on 1) The mixer assembly of claim 1, further comprising: a pilot fuel injector tip including a least one pilot fuel orifice, the fuel injection port being the pilot fuel orifice; and a pilot swirler is located radially outward of the pilot fuel injector tip and adjacent to the pilot fuel injector tip, air being configured to flow through the pilot swirler and to mix with fuel from the pilot fuel orifice as a fuel-air mixture, the pilot swirler having an outlet configured to discharge the fuel-air mixture into the passage. ### Claim 15 (depends on 14) The mixer assembly of claim 14, further comprising an array of main fuel injection orifices configured to inject fuel in a radially outward direction, the main fuel injection orifices being located radially outward from the passage. ### Claim 16 (depends on 14) The mixer assembly of claim 14, wherein the passage is a venturi including a converging section, a diverging section, and a throat, the coated passage wall including a passage wall of the diverging section, and the outlet of the pilot swirler being located upstream of the diverging section. ### Claim 17 (depends on 16) The mixer assembly of claim 16, wherein the pilot swirler is formed by a housing, the housing being shaped as a venturi. ### Claim 18 (depends on 1) A gas turbine engine comprising: a combustor including a combustion chamber; and the mixer assembly of claim 1 configured to inject a mixture of air and hydrocarbon fuel into the combustion chamber. ### Claim 19 (depends on 18) The gas turbine engine of claim 18, wherein the combustor is configured to combust the mixture of air and the hydrocarbon fuel to generate combustion products, and wherein the gas turbine engine further comprises at least one component coated with a thermal barrier coating downstream of the combustor and configured to receive the combustion products. ### Claim 20 (depends on 18) The gas turbine engine of claim 18, wherein the mixer assembly includes a heat shield adjacent to the combustion chamber, at least a portion of the heat shield being coated with a layer of the catalytic metal.