# US 2009/0260604 A1 · Three-Pass Heat Exchanger for an EGR System > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260604 A1 - Document ID: US20090260604A1 - Status: Published application - Kind: A1 - Application number: 12/085,305 - Filed: 2006-11-22 - Published: 2009-10-22 - Earliest claimed: 2005-11-22 - Assignees: Dayco Ensa, S.L. - Inventors: Carlos Manuel Castano Gonzalez; Jose Antonio Grande Fernandez - Web page: https://patentgrep.com/patent/US20090260604A1 ## CPC - F28F 27/02: for controlling the distribution of heat-exchange media between different channels ({static flow control means in header boxes F28F9/026}; arrangements of guide plates or guide vanes F28F9/22, F28F25/12) - F02M 26/26: characterised by details of the bypass valve - F02M 26/32: Liquid-cooled heat exchangers - F28D 7/1638: {with particular pattern of flow or the heat exchange medium flowing inside the conduits assemblies, e.g. change of flow direction from one conduit assembly to another one (F28D7/1661, F28D7/1676 take precedence)} - F28D 7/1676: {with particular pattern of flow of the heat exchange media, e.g. change of flow direction} - F28D 21/0003: {the heat being recuperated from exhaust gases (F28D21/0014 takes precedence)} - F28F 2250/06: Derivation channels, e.g. bypass - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - 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) ## Abstract The present invention relates to a three-pass heat exchanger for an EGR system, comprising a casing housing at least one cooling chamber for gas circulating through a plurality of pipes and heads on its ends coupled to the gas inlet pipe coming from the exhaust manifold and to the gas outlet pipe connected to the intake manifold of the engine, which is configured as a three-pass heat exchanger, i.e. with three differentiated areas for gas circulation from the inlet pipe to the outlet pipe, the inlet pipe and the outlet pipe being located at opposite ends of the exchanger. The exchanger can include a bypass valve and two cooling chambers at different temperatures. ## Claims ### Claim 1 A heat exchanger (11, 41) for an EGR system comprising a casing (13, 43) housing at least one cooling chamber for the gas circulating through a plurality of pipes and heads (15, 17; 45, 47) at its ends coupled to the gas inlet pipe coming from the exhaust manifold and to the gas outlet pipe connected to the intake manifold of the engine, characterized in that: a) it is configured with three differentiated area (21, 23, 25; 51, 53, 55) for gas circulation from the inlet pipe to the outlet pipe; b) the inlet pipe and the outlet pipe are located at opposite ends of the exchanger (11, 41). ### Claim 2 (depends on 1) A heat exchanger (11) for an EGR system according to claim 1, characterized in that: a) the casing (13) has a circular section and the three differentiated gas circulation areas (21, 23, 25) are arranged concentrically inside a single cooling chamber; b) the inlet head (15) includes a part (27) which, on its outer side, closes off the access of the inlet gas to the inner area (25) and the intermediate area (23), but it allows the passage thereof to the outer area (21) and, on its inner side, facilitates gas circulation from the intermediate area (23) to the inner area (25); c) the outlet head (17) includes a distribution chamber (29) for distributing the gas coming from the outer area (21) to the intermediate area (23). ### Claim 3 (depends on 2) A heat exchanger (11) for an EGR system according to claim 2, characterized in that the gas passage pipes are distributed in a ring shape at least in the outer area (21) and in the intermediate area (23). ### Claim 4 (depends on 1) A heat exchanger (11) for an EGR system according to claim 1, characterized in that: a) the casing (13) has a circular section and the three differentiated gas circulation areas (21, 23, 25) are arranged concentrically inside a single cooling chamber, the outer area (25) being formed by a single pipe; b) the inlet head (15) includes a part (31) with a bypass valve (35) so as to, on one hand, regulate the access of the inlet gas either to the outer area (21) or to the inner area (25), and on the other hand to facilitate gas circulation from the intermediate area (25) to the inner area (25); c) the outlet head (17) includes a distribution chamber (29) for distributing the gas coming from the outer area (21) to the intermediate area (23); d) the inner area (25) extends through the outlet head (17) to the outside of the exchanger, functioning as a gas outlet pipe. ### Claim 5 (depends on 4) A heat exchanger (11) for an EGR system according to claim 4, characterized in that the bypass valve (35) has a proportional actuator (37) so as to be able to distribute the inlet gas between the outer area (21) and the inner area (25). ### Claim 6 (depends on 5) A heat exchanger (11) for an EGR system according to claim 5, characterized in that the control means of the bypass valve (35) allow controlling said distribution by taking into account the outlet gas temperature provided by a temperature sensor. ### Claim 7 (depends on 4) A heat exchanger (11) for an EGR system according to claim 4, characterized in that the gas passage pipes in the outer area (21) and in the intermediate area (23) are distributed in a ring shape. ### Claim 8 (depends on 1) A heat exchanger (41) for an EGR system according to claim 1, characterized in that: a) the casing (43) has a circular section, the first gas circulation area (51) occupying one of its halves, and the second gas circulation area (53) and the third gas circulation area (55) occupying the other half, this latter area being located on a side close to the casing (43); b) the inlet head (45) includes a part (57) which, on its outer side, closes off the access of the inlet gas to the second area (53) and the third area (55), but it allows the passage thereof to the first area (51) and, on its inner side, facilitates gas circulation from the second area (53) to the third area (55); c) the outlet head (47) includes a distribution chamber (69) for distributing the gas coming from the first area (51) to the second area (53). ### Claim 9 (depends on 1) A heat exchanger (41) for an EGR system according to claim 1, characterized in that: a) the casing (43) has a circular section, the first gas circulation area (51) occupying one of its halves, and the second gas circulation area (53) and the third gas circulation area (55) occupying the other half, this latter area being located on a side close to the casing (43) and being formed by a single pipe; b) the inlet head (45) includes a part (57) on one hand to regulate the access of the inlet gas either to the first area (51) or to the third area (55) by means of a bypass valve (68), and on the other hand to facilitate gas circulation from the second area (53) to the third area (55); c) the outlet head (47) includes a distribution chamber (69) for distributing the gas coming from the first area (51) to the second area (53); d) the third area (55) extends through the outlet head (47) to the outside of the exchanger, functioning as a gas outlet pipe. ### Claim 10 (depends on 9) A heat exchanger (41) for an EGR system according to claim 9, characterized in that the bypass valve (68) has a proportional actuator (77) so as to be able to distribute the inlet gas between the first area (51) and the third area (55). ### Claim 11 (depends on 10) A heat exchanger (41) for an EGR system according to claim 10, characterized in that the control means of the bypass valve (68) allow controlling said distribution by taking into account the outlet gas temperature provided by a temperature sensor. ### Claim 12 (depends on 8) A heat exchanger (41) for an EGR system according to claim 8, characterized in that it includes two cooling chambers (61, 63) at different temperatures, the first gas circulation area (51) being located inside the cooling chamber with greater cooling capacity (61) and the second gas circulation area (53) and the third gas circulation area (55) being located inside the cooling chamber with less cooling capacity (63). ### Claim 13 (depends on 12) A heat exchanger (41) for an EGR system according to claim 12, characterized in that the two cooling chambers (61, 63) are demarcated by a central plate (49) located inside the outer casing (43). ### Claim 14 (depends on 12) A heat exchanger (41) for an EGR system according to claim 12, characterized in that the two cooling chambers are structured as separate semi-casings (71, 73). ### Claim 15 (depends on 3) A heat exchanger (11) for an EGR system according to claim 3, characterized in that each differentiated gas circulation area (21, 23, 25; 51, 53, 55) includes a different number of gas passage pipes. ### Claim 16 (depends on 3) A heat exchanger (11) for an EGR system according to claim 3, characterized in that at least one of the differentiated gas circulation areas (21, 23, 25; 51, 53, 55) includes gas passage pipes of a circular section with a different diameter than the pipes of the other areas. ### Claim 17 (depends on 3) A heat exchanger (11) for an EGR system according to claim 3, characterized in that at least one of the differentiated gas circulation areas (21, 23, 25; 51, 53, 55) includes gas passage pipes of a different degree of heat exchange than the pipes of the other areas. ### Claim 18 (depends on 3) A heat exchanger (11) for an EGR system according to claim 3, characterized in that at least one of the differentiated gas circulation areas (21, 23, 25; 51, 53, 55) includes gas passage pipes of a different cross section than the pipes of the other areas.