Heat exchanger for an EGR system with an integrated by-pass duct.

A heat exchanger (1) for an EGR system with an integrated by-pass duct (9). A heat exchanger for recirculated exhaust gases of an internal combustion engine is proposed with an integrated by-pass duct (9) through which the exhaust gases can recirculate during the engine starting and/or in low temperature or load conditions. The exchanger is formed by a cylindrical casing (2) inside of which the typical refrigeration chamber (3) in this type of devices is assembled, as well as the by-pass duct (9) . As a coupling means to the gas intake device of the EGR system, a flange (15,16) is used with a housing for the refrigerating tubes of the refrigeration chamber and another housing (22) for the by-pass duct; with a separation area (23) between said housings. The by-pass duct can be a double-walled duct with an intermediate air chamber to prevent the cooling of the gases circulating through it.