Two stage mixing system for exhaust gas recirculation (EGR)

A two stage mixing system for exhaust gas recirculation (EGR) in an internal combustion engine, comprising:

• a mixing conduit forming a mixing chamber;
• an intake air conduit connected to the mixing conduit;
• a supply conduit connected to the mixing conduit;
• a plenum disposed on the circumference of the mixing conduit, where the plenum forms an annular cavity;
• an EGR conduit connected to the plenum;
• and
• at least one cross conduit disposed across the mixing chamber, where each cross conduit is connected at both ends to the plenum, where each cross conduit has an upstream side and a downstream side, where each cross conduit has a first transition region between the upstream and downstream sides, where each cross conduit has a second transition region between the upstream and downstream sides, and where each cross conduit forms at least one outlet on the first and second transition regions.

A two stage mixing device for exhaust gas recirculation (EGR) in an internal combustion engine, comprising:

• a mixing conduit forming a mixing chamber;
• a plenum disposed on the circumference of the mixing conduit, where the plenum forms an annular cavity;
• and
• at least one cross conduit disposed across the mixing chamber, where each cross conduit is connected at both ends to the plenum, where each cross conduit has an upstream side and a downstream side, where each cross conduit has a first transition region between the upstream and downstream sides, where each cross conduit has a second transition region between the upstream and downstream sides, and where each cross conduit forms at least one outlet on the first and second transition regions.

A method for an internal combustion engine, comprising the steps of:

• flowing an amount of exhaust gas into an exhaust conduit;
• diverting a portion of the amount of exhaust gas into an EGR conduit that is connected to a plenum;
• flowing an amount of intake air into an intake air conduit;
• mixing the amount of intake air with the portion of exhaust gas in a mixing conduit that is disposed between the intake air conduit and the plenum;
• injecting exhaust gas from at least two locations of the plenum that are connected to each other with at least one cross conduit.