# US 9,435,537 B2 · System and method for premixer wake and vortex filling for enhanced flame-holding resistance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,537 B2 - Document ID: US9435537B2 - Status: Granted - Kind: B2 - Application number: 12/956,187 - Filed: 2010-11-30 - Published: 2012-05-31 - Granted: 2016-09-06 - Earliest claimed: 2010-11-30 - Assignees: General Electric Company - Applicants: Ahmed Mostafa ELKady; Christian Lee Vandervort; Kishore Ramakrishnan - Inventors: Ahmed Mostafa ELKady; Christian Lee Vandervort; Kishore Ramakrishnan - Web page: https://patentgrep.com/patent/US9435537B2 ## CPC - F23R 3/14: by using swirl vanes - F23R 3/12: inducing a vortex - F23R 3/286: {having fuel-air premixing devices (F23R3/30 takes precedence)} - F23D 2900/14021: Premixing burners with swirling or vortices creating means for fuel or air - 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) - F23D: BURNERS ## Abstract A combustion system premixer includes one or more streamwise vortex generators configured to passively redirect surrounding high velocity air into at least one of wake and vortex regions within a combustion system fuel nozzle in response to air passing through the premixer. The streamwise vortex generators operate to minimize turbulent flow structures, thus improving air/fuel mixing, and enhancing resistance to flame-holding and flash-back within the premixer. ## Claims ### Claim 1 A combustion system premixer comprising: one or more streamwise vortex generators configured to passively redirect surrounding high velocity air into at least one of wake and vortex regions within a combustion system fuel nozzle to reduce turbulent flow structures in response to the high velocity air passing therethrough; wherein the one or more streamwise vortex generators comprise at least one notch structure, at least one shaped groove, or at least one serration extending axially with respect to a longitudinal axis of a swirler mechanism and forming a trailing edge of a downstream edge portion of a first annular component of the swirler mechanism of the combustion system premixer and at least one notch structure, at least one shaped groove, or at least one serration extending axially with respect to a longitudinal axis of the swirler mechanism and forming a trailing edge of a downstream portion of a second annular component of the swirler mechanism concentric with the first annular component; and wherein the first component of the swirler mechanism comprises swirler vanes extending radially outward of the trailing edge. ### Claim 2 (depends on 1) The combustion system premixer according to claim 1, wherein at least one streamwise vortex generator is configured to generate vortices in response to air passing through the premixer, such that the vortices passively fill in a wake region associated with the air passing through the premixer, and further, such that flame-holding resistance is increased within the premixer. ### Claim 3 (depends on 1) The combustion system premixer according to claim 1, wherein at least one streamwise vortex generator is configured to generate vortices in response to air passing through the premixer, such that the vortices passively fill in a wake region associated with the air passing through the premixer, and further such that flash-back resistance is increased within the premixer. ### Claim 4 (depends on 1) The combustion system premixer according to claim 1, wherein the premixer comprises a dry low nitrogen oxide (DLN) type fuel premixer. ### Claim 5 A combustion system premixer comprising: a swirler mechanism comprising a first annular component and a second annular component concentric with the first annular component, the first annular component including a first series of rotating air flow turning vanes and a downstream portion, the second annular component including a second series of one of counter-rotating or co-rotating air flow turning vanes, and a downstream portion; one or more injection orifices, and a trailing edge of the downstream portion of the first annular component of the swirler mechanism comprising one or more streamwise vortex generators and a trailing edge of the downstream portion of the second annular component of the swirler mechanism comprising one or more streamwise vortex generators, wherein each of the streamwise vortex generators comprise at least one notch structure, at least one shaped groove, or at least one serration extending axially with respect to a longitudinal axis of the swirler mechanism and forming the trailing edge, and wherein each of the streamwise vortex generators are configured to passively redirect surrounding high velocity air or fuel injected into the trailing edge region via the one or more injection orifices such that the redirected air or fuel mixes out at least one of wake and vortex regions generated downstream from the trailing edge regions. ### Claim 6 (depends on 5) The combustion system premixer according to claim 5, wherein at least one injection orifice is substantially aligned with air flowing through a trailing edge region. ### Claim 7 (depends on 5) The combustion system premixer according to claim 5, wherein at least one injection orifice is substantially misaligned with air flowing through a trailing edge region. ### Claim 8 (depends on 5) The combustion system premixer according to claim 5, wherein the injection of air or fuel is substantially constant. ### Claim 9 (depends on 5) The combustion system premixer according to claim 5, wherein the injection of air or fuel is pulsatile.