# US 8,539,775 B1 · Gas turbine engines and systems and methods for removing particulate matter therefrom during operation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,539,775 B1 - Document ID: US8539775B1 - Status: Granted - Kind: B1 - Application number: 13/426,337 - Filed: 2012-03-21 - Published: 2013-09-26 - Granted: 2013-09-24 - Earliest claimed: 2012-03-21 - Assignees: Honeywell International Inc. - Applicants: Yates Wong - Inventors: Yates Wong - Web page: https://patentgrep.com/patent/US8539775B1 ## CPC - F02C 7/30: Preventing corrosion {or unwanted deposits} in gas-swept spaces - 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) ## Abstract Systems and methods are provided for removing particulate matter from gas turbine engines during operation are provided. Gas turbine engines are also provided. The particulate matter is suspended in a primary gas flow stream passing through an engine flowpath. A flowpath surface of the engine flowpath is electrostatically charged to a first polarity to thereby impart an electrostatic charge of the first polarity to the particulate matter. A bleed discharge duct is electrostatically charged to a second polarity and intersects the engine flowpath to define a bleed air flowpath. The second polarity is opposite to the first polarity. A bleed port is in fluid communication with the bleed discharge duct and has an outlet exterior of the gas turbine engine. ## Claims ### Claim 1 A system for removing particulate matter from an operating gas turbine engine, the particulate matter suspended in a primary gas flow stream passing through an engine flowpath, the system comprising: a flowpath surface of each portion of the engine flowpath electrostatically charged to a first polarity to thereby impart an electrostatic charge of the first polarity to the particulate matter; a bleed discharge duct electrostatically charged to a second polarity and intersecting the engine flowpath to define a bleed air flowpath, the second polarity opposite to the first polarity; and a bleed port in flow communication with the bleed discharge duct and having an outlet exterior of the gas turbine engine. ### Claim 2 (depends on 1) The system of claim 1, further comprising: a plurality of inside engine components located along the engine flowpath, each having a plurality of surfaces electrostatically charged to the first polarity, at least one comprising the electrostatically charged flowpath surface. ### Claim 3 (depends on 1) The system of claim 1, further comprising means for imparting the electrostatic charge. ### Claim 4 (depends on 1) The system of claim 1, wherein the particulate matter having the electrostatic charge of the same first polarity as the electrostatically charged flowpath surface comprises primary charged particulate matter, the electrostatically charged flowpath surface configured to repel the primary charged particulate matter when brought into proximity therewith and the electrostatically charged bleed discharge duct configured to attract the primary charged particulate matter. ### Claim 5 (depends on 1) The system of claim 1, wherein the electrostatically charged flowpath surface comprises a rotating compressor blade. ### Claim 6 (depends on 1) The system of claim 1, wherein the operating gas turbine engine comprises a high pressure compressor and a combustor assembly, the electrostatically charged bleed discharge duct located at a bleed location between an impeller inlet and impeller exit of the high pressure compressor, at a discharge of the high pressure compressor, in the combustor assembly, or a combination thereof. ### Claim 7 (depends on 4) The system of claim 4, wherein the electrostatically charged bleed discharge duct is selectively located where particulate matter collects, to take advantage of the greater inertia and momentum of the particulate matter relative to air in the primary gas flow stream, or both. ### Claim 8 (depends on 7) The system of claim 7, wherein the electrostatically charged bleed discharge duct is selectively located immediately upstream of a flowpath turn, the flowpath turn configured to cause the primary gas flow stream to take a change in direction to channel the primary charged particulate matter therein into the electrostatically charged bleed discharge duct. ### Claim 9 A method for removing particulate matter from an operating gas turbine engine while passing a primary gas flow stream with particulate matter suspended therein through an engine flowpath of the operating gas turbine engine, the method comprising the steps of: maintaining an electrostatic charge of a first polarity on a flowpath surface of each portion of the engine flowpath; maintaining an electrostatic charge of the first polarity on the particulate matter; and maintaining an electrostatic charge of a second polarity on a bleed discharge duct intersecting the engine flowpath at a bleed location, the bleed discharge duct defining a bleed air flowpath and in flow communication with an associated bleed port having an outlet exterior of the operating gas turbine engine. ### Claim 10 (depends on 9) The method of claim 9, wherein the step of maintaining an electrostatic charge of a first polarity on a flowpath surface comprises maintaining the electrostatic charge of the first polarity on a plurality of inside engine surfaces, at least one inside engine surface of the plurality of inside engine surfaces comprising the flowpath surface. ### Claim 11 (depends on 10) The method of claim 10, further comprising providing electrostatic charging means for imparting an electrostatic charge. ### Claim 12 (depends on 11) The method of claim 11, wherein the step of maintaining an electrostatic charge of the first polarity on the particulate matter comprises imparting an electrostatic charge thereon by the electrostatic charging means or by direct transfer from the electrostatically charged flowpath surface. ### Claim 13 (depends on 10) The method of claim 10, wherein the step of maintaining an electrostatic charge of the first polarity on the particulate matter provides primary charged particulate matter and the step of maintaining an electrostatic charge of a second polarity on a bleed discharge duct provides a secondary charged bleed discharge duct, the method further comprising selectively locating the bleed location where particulate matter collects, to take advantage of the greater inertia and momentum of the particulate matter relative to air in the primary gas flow stream, or both. ### Claim 14 (depends on 13) The method of claim 13, wherein the step of selectively locating the bleed location comprises selectively locating the bleed location immediately upstream of a flowpath turn, the flowpath turn configured to cause the primary gas flow stream to take a change in direction to channel the primary charged particulate matter therein into the secondary charged bleed discharge duct. ### Claim 15 A gas turbine engine comprising: an inside engine component having a plurality of surfaces including a flowpath surface defining at least a portion of an engine flowpath, at least the flowpath surface and the engine flowpath configured to be electrostatically charged to a first polarity and to be exposed during operation of the gas turbine engine to a primary gas flow stream with particulate matter suspended therein; a bleed discharge duct intersecting the engine flowpath to define a bleed air flowpath, the bleed discharge duct configured to be electrostatically charged to a second polarity, the second polarity opposite the first polarity; and a bleed port in flow communication with the bleed discharge duct, the bleed port having an outlet exterior of the gas turbine engine. ### Claim 16 (depends on 15) The gas turbine engine of claim 15, wherein the electrostatically charged flowpath surface is configured to directly transfer the electrostatic charge of the first polarity to the particulate matter to provide primary charged particulate matter in the primary gas flow stream. ### Claim 17 (depends on 16) The gas turbine engine of claim 16, wherein the electrostatically charged flowpath surface repels the primary charged particulate matter in the primary gas flow stream and the electrostatically charged bleed discharge duct is configured to attract the primary charged particulate matter. ### Claim 18 (depends on 17) The gas turbine engine of claim 17, wherein the inside engine component comprises a low pressure compressor, a high pressure compressor, a combustor assembly, a turbine assembly, or a combination thereof and the bleed discharge duct is located between an inlet and a discharge of the high pressure compressor, at the discharge of the high pressure compressor, in the combustor assembly, or a combination thereof. ### Claim 19 (depends on 18) The gas turbine engine of claim 18, wherein the bleed discharge duct is selectively located where particulate matter collects, to take advantage of the greater inertia and momentum of the particulate matter relative to air in the primary gas flow stream, or both. ### Claim 20 (depends on 19) The method of claim 19, wherein the bleed discharge duct is selectively located immediately upstream of a flowpath turn, the flowpath turn configured to cause the primary gas flow stream to take a change in direction to channel the primary charged particulate matter therein into the electrostatically charged bleed discharge duct.