# US 11,029,095 B2 · Finned coaxial cooler > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,095 B2 - Document ID: US11029095B2 - Status: Granted - Kind: B2 - Application number: 15/211,609 - Filed: 2016-07-15 - Published: 2017-02-02 - Granted: 2021-06-08 - Earliest claimed: 2015-07-30 - Assignees: Senior UK Limited - Applicants: Senior UK Limited - Inventors: Charles Penny; Adrian Ware; Ragu Subramanyam - Web page: https://patentgrep.com/patent/US11029095B2 ## CPC - F28D 7/106: {consisting of two coaxial conduits or modules of two coaxial conduits} - F02M 26/32: Liquid-cooled heat exchangers - F28D 7/14: both tubes being bent - F28D 21/0003: {the heat being recuperated from exhaust gases (F28D21/0014 takes precedence)} - F28F 1/08: Tubular elements crimped or corrugated in longitudinal section - F28F 1/426: {the outside portions and the inside portions forming parts of complementary shape, e.g. concave and convex} - F28F 13/12: by creating turbulence, e.g. by stirring, by increasing the force of circulation (F28F13/08 takes precedence) - F28D 2021/0026: {for combustion engines, e.g. for gas turbines or for Stirling engines} - F28F 2265/26: for allowing differential expansion between elements - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) ## Abstract A heat exchanger (100) for an exhaust gas recirculation system includes one or more rigid tubes (103), each having one or more internal cooling fins (111) that act as heat exchange surfaces to transfer heat from a gas to the walls of the rigid tubes. The rigid tubes are cooled by a liquid coolant contained within an outer jacket (113) surrounding the tubes. The rigid tubes may be straight and smooth, and may be alternated with one or more bellows sections (108, 104) which provide flexibility to the heat exchanger. ## Claims ### Claim 1 A heat exchanger for cooling a hot gas using a liquid coolant, said heat exchanger comprising: an inner heat exchange tube adapted for exchanging heat between said gas and said liquid coolant; a tubular outer body surrounding at least part of said inner heat exchange tube, wherein said heat exchanger is configured to enable said gas to flow through said inner heat exchange tube and said liquid coolant to flow between said inner heat exchange tube and said tubular outer body; and a single fin component, said single fin component comprising: one or more fins of a first fin type being in contact with an inner surface of said inner heat exchange tube; and one or more fins of a second fin type also being in contact with said inner surface of said inner heat exchange tube, said one or more fins of the first fin type having a first length that extends inwardly by a first distance toward the central axis of said heat exchanger, said one or more fins of the second fin type having a second length that extends inwardly by a second distance toward the central axis of said heat exchanger, such that the first length and the first distance are different in value from the second length and the second distance, said one or more fins of the first fin type and said one or more fins of the second fin type being integrated to form the single fin component, said single fin component being configured to be fitted inside said inner heat exchange tube, and said single fin component comprising a resilient metal having resilience such as to cause said single fin component, upon insertion into said inner heat exchange tube, to expand outwardly, to thereby retain itself by friction inside said inner heat exchange tube. ### Claim 2 (depends on 1) The heat exchanger as claimed in claim 1, wherein said inner heat exchange tube is straight over at least part of a length of said inner heat exchange tube. ### Claim 3 (depends on 1) The heat exchanger as claimed in claim 1, in which said one or more fins of the first fin type and said one or more fins of the second fin type each comprise a plurality of fin walls extending inwardly between said inner surface of said inner heat exchange tube and towards a center of a passage through said inner heat exchange tube. ### Claim 4 (depends on 1) The heat exchanger as claimed in claim 1, in which said one or more fins of the first fin type and said one or more fins of the second fin type each comprise a plurality of fin walls extending inwardly between said inner surface of said heat exchange tube and towards a center of a passage through said inner heat exchange tube, to form corresponding radially outermost extremities of said fin walls, wherein said plurality of fin walls are connected by a corresponding plurality of circumferentially extending walls connecting said corresponding radially outermost extremities of said fin walls. ### Claim 5 (depends on 1) The heat exchanger as claimed in claim 1, in which said one or more fins of the first fin type and said one or more fins of the second fin type each comprise a plurality of fin walls which extend inwardly from said inner surface of said inner heat exchange tube towards the central axis of said inner heat exchange tube. ### Claim 6 (depends on 1) The heat exchanger as claimed in claim 1, in which said one or more fins of the first fin type and said one or more fins of the second fin type each comprise a plurality of axially extending gas passages which occupy a substantially annular region in a direction perpendicular to the central axis of said inner heat exchange tube. ### Claim 7 (depends on 1) The heat exchanger as claimed in claim 1, wherein one or more of said fins comprises one or a plurality of protrusions extending in a circumferential direction of said heat exchanger. ### Claim 8 (depends on 1) The heat exchanger as claimed in claim 1, wherein said one or more fins of the first fin type and said one or more fins of the second fin type are arranged into a plurality of segments, each segment comprising at least one fin. ### Claim 9 (depends on 1) The heat exchanger as claimed in claim 1, wherein said one or more fins of the first fin type and said one or more fins of the second fin type comprise a strip of material formed into a plurality of fins having an overall arc having an angle of less than 360°, wherein said strip of material, when inserted into said inner heat exchange tube, increases said angle of said arc. ### Claim 10 (depends on 9) The heat exchanger as claimed in claim 9, wherein said arc of said fin in contact with the heat exchange tube has a radius greater than said inner heat exchange tube. ### Claim 11 (depends on 1) The heat exchanger as claimed in claim 1, comprising a compensation tube joined to the heat exchanger to accommodate thermal growth and manufacturing tolerances. ### Claim 12 (depends on 1) The heat exchanger as claimed in claim 1, comprising one or more substantially straight smooth sections alternating with one or more corrugated sections, wherein the straight sections have internal finned structures providing heat transfer surfaces which are aligned in an axial direction along the flow of gas. ### Claim 13 (depends on 1) The heat exchanger as claimed in claim 1, that has a plurality of straights and a plurality of bends. ### Claim 14 (depends on 1) The heat exchanger as claimed in claim 1, comprising a plurality of outwardly formed dimples on the inner gas tube that set the gas tube to be substantially concentric within a tubular outer body. ### Claim 15 (depends on 1) The heat exchanger as claimed in claim 1, wherein said one or more fins each comprise fin walls having surfaces that extend in a direction parallel to an axial direction of the heat exchanger, wherein said surfaces of said fin walls extend radially towards the main central axis of said tubular outer body in which said fin walls are located so as to provide a plurality of individual gas passages surrounding a central gas passage, wherein said central gas passage has its center coincident with the central axis of said heat exchanger. ### Claim 16 (depends on 1) The heat exchanger as claimed in claim 1, wherein said single component comprises a plurality of flower-petal-shaped undulations, so that a single central gas passage of said single component, when viewed in a cross-section relative to the direction in which gas is configured to flow through the heat exchanger, appears in the shape of a flower, said single central gas passage being surrounded by a plurality of peripheral gas passages between said single component and said inner surface of said inner heat exchange tube. ### Claim 17 A heat exchanger for cooling hot gas using a liquid coolant, said heat exchanger comprising: an inner heat exchange tube adapted for exchanging heat between a gas and a coolant; a tubular outer body surrounding at least part of said inner heat exchange tube, wherein said heat exchanger is configured to enable said gas to flow through said inner heat exchange tube and said coolant to flow between said inner heat exchange tube and said tubular outer body; and a single fin member which fits inside said inner heat exchange tube, said fin member comprising: a plurality of radially extending first walls each extending along an axial direction of at least a portion of said inner heat exchange tube, said first walls each having a first length that extends inwardly by a first distance towards the central axis of said inner heat exchange tube, and a plurality of radially extending second walls each extending along an axial direction of at least a portion of said inner heat exchange tube, said second walls each having a second length that extends inwardly by a second distance towards the central axis of said inner heat exchange tube, said first distance being different in value from said second distance, and a plurality of circumferentially extending connecting portions, each said connecting portion extending between and connecting an adjacent one of said radially extending first walls to an adjacent one of said radially extending second walls, wherein said fin member is of dimensions such as to fit within said inner heat exchange tube such that an outer surface of each said connecting portion is in contact with an inner surface of said inner heat exchange tube, wherein said fin member is formed from a single strip of resilient metal material having resilience, such as to wherein the resilience of said metal material causes said single fin member, upon insertion into said inner heat exchange tube, to expand outwardly, to thereby retain itself by friction inside said inner heat exchange tube. ### Claim 18 (depends on 17) The heat exchanger as claimed in claim 17, wherein one side of each said circumferentially extending connecting portion is in contact with a central gas flow passage and another side of each said circumferentially extending connecting portion is in contact with said inner wall of said inner heat exchange tube. ### Claim 19 (depends on 15) The heat exchanger as claimed in claim 15, wherein the heat exchanger is configured to enable said gas to flow along said central gas passage and along each of said plurality of individual gas passages surrounding said central gas passage. ### Claim 20 (depends on 17) The heat exchanger as claimed in claim 17, wherein said one or more fins each comprise fin walls having surfaces that extend in a direction parallel to an axial direction of the heat exchanger, wherein said surfaces of said fin walls extend radially towards the main central axis of said tubular outer body in which said fin walls are located so as to provide a plurality of individual gas passages surrounding a central gas passage, wherein said central gas passage has its center coincident with the central axis of said inner heat exchange tube. ### Claim 21 (depends on 20) The heat exchanger as claimed in claim 20, wherein the heat exchanger is configured to enable said gas to flow along said central gas passage and along each of said plurality of individual gas passages surrounding said central gas passage. ### Claim 22 (depends on 17) The heat exchanger as claimed in claim 17, wherein said fin member comprises a plurality of flower-petal-shaped undulations, so that a single central gas passage of said fin member, when viewed in a cross-section relative to the direction in which gas is configured to flow through the heat exchanger, appears in the shape of a flower, said single central gas passage being surrounded by a plurality of peripheral gas passages between said fin member and said inner surface of said inner heat exchange tube.