# US 8,783,007 B2 · Liquid fuel system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,007 B2 - Document ID: US8783007B2 - Status: Granted - Kind: B2 - Application number: 12/773,053 - Filed: 2010-05-04 - Published: 2011-11-10 - Granted: 2014-07-22 - Earliest claimed: 2010-05-04 - Assignees: General Electric Company - Applicants: Julio Enrique Mestroni; Douglas Byrd; Charles Steber; Rahul J. Chillar; Robert R. Reed - Inventors: Julio Enrique Mestroni; Douglas Byrd; Charles Steber; Rahul J. Chillar; Robert R. Reed - Web page: https://patentgrep.com/patent/US8783007B2 ## CPC - F02C 7/22: Fuel supply systems - F02C 9/40: specially adapted to the use of a special fuel or a plurality of fuels - F05D 2260/602: Drainage - 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) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract The present application provides a liquid fuel system for use with a flow of a liquid fuel and a combustor of a gas turbine engine. The liquid fuel system may include a number of fuel lines in communication with the combustor, a purge air inlet positioned about each of the fuel lines, a number of drain lines with each drain line in communication with a respective fuel line, and a number of drain valves with each drain valve in communication with a respective drain line so as to drain the flow of liquid fuel in the fuel lines via a flow of purge air through the purge air inlet and opening the drain valves. ## Claims ### Claim 1 A liquid fuel system for use with a flow of a liquid fuel and a combustor of a gas turbine engine, comprising: a plurality of fuel lines in communication with the combustor; a purge air inlet, in communication with a source of purge air, positioned about each of the fuel lines upstream of the combustor; a check valve positioned on each of the fuel lines upstream of the purge air inlet; a plurality of drain lines, wherein each drain line is in communication with a respective fuel line downstream of the check valve; and a plurality of drain valves, wherein each drain valve is in communication with a respective drain line and configured to allow liquid fuel in the respective fuel lines downstream of the check valve to drain via a flow of purge air through the purge air inlet and opening the drain valves. ### Claim 2 (depends on 1) The liquid fuel system of claim 1, wherein the combustor comprises a primary nozzle intake and a secondary nozzle intake, and wherein the plurality of fuel lines comprises a plurality of primary nozzle fuel lines and a plurality of secondary nozzle fuel lines. ### Claim 3 (depends on 1) The liquid fuel system of claim 1, further comprising a liquid fuel skid positioned apart from the combustor. ### Claim 4 (depends on 3) The liquid fuel system of claim 3, wherein the combustor is positioned within a compartment. ### Claim 5 (depends on 3) The liquid fuel system of claim 3, wherein the liquid fuel skid comprises a pump and a flow divider. ### Claim 6 (depends on 1) The liquid fuel system of claim 1, wherein the plurality of drain lines are in communication with a merged drain line. ### Claim 7 (depends on 6) The liquid fuel system of claim 6, wherein the merged drain line is in communication with a drain tank. ### Claim 8 (depends on 7) The liquid fuel system of claim 7, wherein the drain tank comprises a pressurized drain tank. ### Claim 9 (depends on 3) The liquid fuel system of claim 3, wherein the check valve is positioned on the liquid fuel skid. ### Claim 10 (depends on 4) The liquid fuel system of claim 4, wherein the check valve is positioned outside of the compartment. ### Claim 11 (depends on 7) The liquid fuel system of claim 7, wherein the drain tank is in communication with a liquid fuel container, a liquid fuel skid, or the fuel lines, and wherein the drain tank is configured to return the flow of liquid fuel to the liquid fuel container, the liquid fuel skid, or the fuel lines. ### Claim 12 A method of protecting a flow of liquid fuel in a fuel line from the heat produced by a combustor of a gas turbine engine when the fuel line is not in use, comprising: positioning a purge air inlet about the fuel line upstream of the combustor positioning a check valve on the fuel line upstream of the purge air inlet; positioning a drain valve about the fuel line downstream of the check valve and at an elevation that is less than the combustor; forcing a flow of purge air through the purge air inlet and into the fuel line; opening the drain valve; and flowing the liquid fuel through the drain valve. ### Claim 13 (depends on 12) The method of claim 12, further comprising the step of flowing the liquid fuel to a drain tank. ### Claim 14 (depends on 13) The method of claim 13, further comprising the step of positioning the drain tank at a distance from the combustor. ### Claim 15 (depends on 13) The method of claim 13, further comprising the step of pressurizing the drain tank. ### Claim 16 (depends on 12) The method of claim 12, further comprising the step of returning the flow of fuel to the fuel line. ### Claim 17 (depends on 12) The method of claim 12, further comprising the step of opening and closing the drain valve in a repeated sequence. ### Claim 18 A purge air drain system for use with a flow of a liquid in a liquid line, comprising: a purge air inlet, in communication with a source of purge air, positioned about the liquid line; a check valve positioned on the liquid line upstream of the purge air inlet; a drain line in communication with the liquid line downstream of the check valve; and a drain valve in communication with the drain line and configured to allow so as to drain the flow of liquid in the liquid line downstream of the check valve to drain via a flow of purge air through the purge air inlet and opening the drain valve. ### Claim 19 (depends on 18) The purge air drain system of claim 18, wherein the drain line is in communication with a drain tank. ### Claim 20 (depends on 19) The purge air drain system of claim 19, wherein the drain tank comprises a pressurized drain tank.