# US 10,119,704 B2 · Burner system including a non-planar perforated flame holder > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,704 B2 - Document ID: US10119704B2 - Status: Granted - Kind: B2 - Application number: 15/236,862 - Filed: 2016-08-15 - Published: 2017-02-09 - Granted: 2018-11-06 - Earliest claimed: 2013-02-14 - Assignees: Clearsign Combustion Corporation - Applicants: Clearsign Combustion Corporation - Inventors: Joseph Colannino; Douglas W. Karkow; James K. Dansie; Christopher A. Wiklof - Web page: https://patentgrep.com/patent/US10119704B2 ## CPC - F23D 14/145: {combustion being stabilised at a screen or a perforated plate} - F23D 2203/1017: curved - F23D 2203/102: using perforated plates - F23D 2203/104: Grids, e.g. honeycomb grids - F23D 2212/103: Fibres - F23D: BURNERS ## Abstract A combustion system such as a furnace or boiler includes a non-planar perforated flame holder configured to hold a combustion reaction. ## Claims ### Claim 1 A non-planar perforated flame holder, comprising: an input face configured to receive a fuel-air mixture; an output face configured to emit products of a combustion reaction of the fuel-air mixture; and a non-planar flame holder body having a plurality of perforations extending from the input face to the output face and collectively configured to promote the combustion reaction of the fuel-air mixture within the perforations; wherein when the non-planar perforated flame holder is operably positioned a distance from a fuel nozzle, a central area of the non-planar flame holder body is configured to be further displaced from the fuel nozzle than a perimeter area of the non-planar flame holder body to equalize tensile load through the non-planar flame holder body. ### Claim 2 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the non-planar flame holder body is arcuate. ### Claim 3 (depends on 2) The non-planar perforated flame holder of claim 2, wherein the non-planar flame holder body is a catenary arch. ### Claim 4 (depends on 2) The non-planar perforated flame holder of claim 2, wherein the non-planar flame holder body is parabolic. ### Claim 5 (depends on 2) The non-planar perforated flame holder of claim 2, wherein the non-planar flame holder body is rotationally symmetric. ### Claim 6 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the non-planar flame holder body is a stepped arch. ### Claim 7 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the input face is non-planar and is configured to equalize flow of the fuel-air mixture into the plurality of perforations. ### Claim 8 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the non-planar flame holder body is arcuate and includes a departure angle that is at least 15 degrees, wherein the departure angle defines an angular displacement of an end of the non-planar flame holder body from a center of the non-planar flame holder body, wherein the departure angle is measured from a plane that is perpendicular to a longitudinal axis of the center of the non-planar flame holder body. ### Claim 9 (depends on 8) The non-planar perforated flame holder of claim 8, wherein the non-planar flame holder body is arcuate and includes a departure angle that is at least 30 degrees. ### Claim 10 (depends on 8) The non-planar perforated flame holder of claim 8, wherein the non-planar flame holder body is arcuate and includes a departure angle that is at least 45 degrees. ### Claim 11 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the non-planar flame holder body is a single continuous unit. ### Claim 12 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the non-planar flame holder body includes a plurality of sections that are coupled together to operate as a singular unit. ### Claim 13 (depends on 12) The non-planar perforated flame holder of claim 12, wherein the plurality of sections are coupled together with adhesive. ### Claim 14 (depends on 12) The non-planar perforated flame holder of claim 12, wherein the plurality of sections are held in place with pure compression. ### Claim 15 (depends on 12) The non-planar perforated flame holder of claim 12, wherein the plurality of sections are tiles that include at least one of a ceramic material and a cementatious material. ### Claim 16 (depends on 12) The non-planar perforated flame holder of claim 12, wherein the plurality of sections are cubical, rectangular, triangular, hexagonal, otherwise polygonal, or asymmetric so that the sections naturally fit closely together. ### Claim 17 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the non-planar flame holder body is formed from a ceramic material. ### Claim 18 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the non-planar flame holder body is formed from a cementatious material. ### Claim 19 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the input face is concavely arched to increase view factors between the plurality of perforations to enable thermal radiation exchange between the plurality of perforations. ### Claim 20 (depends on 19) The non-planar perforated flame holder of claim 19, wherein enabling thermal radiation exchange between the plurality of perforations in the input face facilitates maintenance of an operating temperature of the non-planar perforated flame holder. ### Claim 21 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the output face is concavely arched to enable thermal radiation exchange between the plurality of perforations. ### Claim 22 (depends on 21) The non-planar perforated flame holder of claim 21, wherein enabling thermal radiation exchange between the plurality of perforations in the output face facilitates maintenance of an operating temperature of the non-planar perforated flame holder. ### Claim 23 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the output face is convexly arched to facilitate thermal radiation of one or more fluid systems that are positioned proximate to a periphery of the non-planar flame holder body. ### Claim 24 (depends on 1) The non-planar perforated flame holder of claim 1, wherein the input face is configured to receive the fuel-air mixture from a position external to all chords defined by the input face. ### Claim 25 (depends on 24) The non-planar perforated flame holder of claim 24, wherein at least one of the perforations is configured to receive the fuel-air mixture with a trajectory substantially parallel to at least one sidewall of the at least one of the perforations. ### Claim 26 A combustion system, comprising: a fuel and oxidant source configured to output a fuel and oxidant mixture; and a non-planar perforated flame holder positioned downstream from the fuel and oxidant source to receive the fuel and oxidant mixture and configured to hold a combustion reaction supported by the fuel and oxidant mixture, the non-planar perforated flame holder, including: a non-planar input face configured to receive the fuel and oxidant mixture; an output face configured to output products of a combustion reaction of the fuel and oxidant mixture; and a perforated flame holder body defining a plurality of perforations extending from the input face to the output face, the perforations being collectively configured to hold the combustion reaction; wherein when the non-planar perforated flame holder is operably positioned a distance from the fuel and oxidant source, a central area of the perforated flame holder body is configured to be further displaced from the fuel and oxidant source than a perimeter area of the perforated flame holder body to reduce variation of a flow rate of the fuel and oxidant mixture across the input face. ### Claim 27 (depends on 26) The combustion system of claim 26, wherein the combustion system is a portion of a boiler system. ### Claim 28 (depends on 26) The combustion system of claim 26, wherein the non-planar input face is configured to equalize flow of the fuel and oxidant mixture into the plurality of perforations. ### Claim 29 (depends on 26) The combustion system of claim 26, wherein the perforated flame holder body is arcuate. ### Claim 30 (depends on 29) The combustion system of claim 29, wherein the perforated flame holder body is a catenary arch. ### Claim 31 (depends on 29) The combustion system of claim 29, wherein the perforated flame holder body is parabolic. ### Claim 32 (depends on 29) The combustion system of claim 29, wherein the perforated flame holder body is rotationally symmetric. ### Claim 33 (depends on 29) The combustion system of claim 29, wherein the perforated flame holder body is a stepped arch. ### Claim 34 (depends on 26) The combustion system of claim 26, wherein the perforated flame holder body is non-planar to equalize tensile load. ### Claim 35 (depends on 26) The combustion system of claim 26, wherein the perforated flame holder body is arcuate and includes a departure angle that is at least 15 degrees, wherein the departure angle defines an angular displacement of an end of the perforated flame holder body from a center of the perforated flame holder body, wherein the departure angle is measured from a plane that is perpendicular to a longitudinal axis of the center of the perforated flame holder body. ### Claim 36 (depends on 35) The combustion system of claim 35, wherein the perforated flame holder body is arcuate and includes a departure angle that is at least 30 degrees. ### Claim 37 (depends on 35) The combustion system of claim 35, wherein the perforated flame holder body is arcuate and includes a departure angle that is at least 45 degrees. ### Claim 38 (depends on 26) The combustion system of claim 26, wherein the perforated flame holder body includes a plurality of sections that are coupled together to operate as a singular unit. ### Claim 39 (depends on 38) The combustion system of claim 38, wherein the plurality of sections are coupled together with adhesive. ### Claim 40 (depends on 38) The combustion system of claim 38, wherein the plurality of sections are held in place with pure compression. ### Claim 41 (depends on 38) The combustion system of claim 38, wherein the plurality of sections are tiles that include at least one of a ceramic material and a cementatious material. ### Claim 42 (depends on 38) The combustion system of claim 38, wherein the plurality of sections are cubical, rectangular, triangular, hexagonal, otherwise polygonal, or asymmetric so that the sections naturally fit closely together. ### Claim 43 (depends on 26) The combustion system of claim 26, wherein the perforated flame holder body is formed from a ceramic material or cementatious material. ### Claim 44 (depends on 26) The combustion system of claim 26, wherein the input face is concavely arched to increase view factors between the plurality of perforations to enable thermal radiation exchange between the plurality of perforations. ### Claim 45 (depends on 44) The combustion system of claim 44, wherein enabling thermal radiation exchange between the plurality of perforations in the input face facilitates maintenance of an operating temperature of the non-planar perforated flame holder. ### Claim 46 (depends on 26) The combustion system of claim 26, wherein the output face is concavely arched to enable thermal radiation exchange between the plurality of perforations. ### Claim 47 (depends on 46) The combustion system of claim 46, wherein enabling thermal radiation exchange between the plurality of perforations in the output face facilitates maintenance of an operating temperature of the non-planar perforated flame holder. ### Claim 48 (depends on 26) The combustion system of claim 26, wherein the output face is convexly arched to facilitate thermal radiation of one or more fluid systems that are positioned proximate to a periphery of the perforated flame holder body. ### Claim 49 (depends on 26) The combustion system of claim 26, wherein the fuel and oxidant source includes a fuel nozzle configured to output a fuel stream toward the perforated flame holder and to mix with the oxidant to form the fuel and oxidant mixture. ### Claim 50 (depends on 49) The combustion system of claim 49, wherein one or more of the perforations extend in a direction parallel to the fuel stream. ### Claim 51 A method of operating a combustion system, comprising: outputting fuel from a nozzle to generate a fuel-air mixture; receiving the fuel-air mixture with a non-planar perforated flame holder, wherein the non-planar perforated flame holder includes a plurality of perforations that extend from an input face to an output face of the non-planar perforated flame holder; and sustaining a combustion reaction of the fuel-air mixture substantially within the plurality of perforations; wherein sustaining the combustion reaction further includes: maintaining an operating temperature of the non-planar perforated flame holder by recycling thermal radiation in between at least some of the plurality of perforations of the input face, wherein the non-planar perforated flame holder recycles the thermal radiation with a concavely shaped input face that provides non-zero view factors between the plurality of perforations at the input face. ### Claim 52 A method of operating a combustion system, comprising: outputting fuel from a nozzle to generate a fuel-air mixture; receiving the fuel-air mixture with a non-planar perforated flame holder, wherein the non-planar perforated flame holder includes a plurality of perforations that extend from an input face to an output face of the non-planar perforated flame holder; and sustaining a combustion reaction of the fuel-air mixture substantially within the plurality of perforations; wherein sustaining the combustion reaction includes: maintaining an operating temperature of the non-planar perforated flame holder by recycling thermal radiation in between at least some of the plurality of perforations at the output face, wherein the non-planar perforated flame holder recycles the thermal radiation with a concavely shaped output face that provides non-zero view factors between the plurality of perforations at the output face. ### Claim 53 A method of operating a combustion system, comprising: outputting fuel from a nozzle to generate a fuel-air mixture; receiving the fuel-air mixture with a non-planar perforated flame holder, wherein the non-planar perforated flame holder includes a plurality of perforations that extend from an input face to an output face of the non-planar perforated flame holder; and sustaining a combustion reaction of the fuel-air mixture substantially within the plurality of perforations; heating one or more fluid systems positioned proximate to the non-planar perforated flame holder by directing thermal radiation from least some of the plurality of perforations on the output face to the one or more fluid systems, wherein the non-planar perforated flame holder directs the thermal radiation with a convexly shaped output face that provides non-zero view factors between at least some of the plurality of perforations and the one or more fluid systems. ### Claim 54 A method of operating a combustion system, comprising: outputting fuel from a nozzle to generate a fuel-air mixture; receiving the fuel-air mixture with a non-planar perforated flame holder, wherein the non-planar perforated flame holder includes a plurality of perforations that extend from an input face to an output face of the non-planar perforated flame holder; and sustaining a combustion reaction of the fuel-air mixture substantially within the plurality of perforations; equalizing a flow rate of the fuel-air mixture at the input face of the non-planar perforated flame holder by positioning a central portion of the non-planar perforated flame holder at a greater distance away from the nozzle than a peripheral portion of the non-planar perforated flame holder with the input face having an arcuate shape. ### Claim 55 (depends on 54) The method of claim 54, wherein the arcuate shape includes at least one of a parabolic arch, a spherical arch, a stepped arch, and a catenary arch. ### Claim 56 (depends on 55) The method of claim 55, further comprising receiving the fuel-air mixture into at least one of the perforations with a trajectory substantially parallel to a sidewall of the at least one of the perforations.