US Patent 7568340 Exhaust gas recirculation mixer

The present invention provides an exhaust gas recirculation mixer for use with a long route (i.e., low pressure) EGR system adapted for use in a turbocharged internal combustion engine. The mixer comprises an outer wall and an inner wall defining a cavity therebetween, a chamber defined within the inner wall, an exhaust gas inlet on the outer wall, and apertures of varying dimensions disposed within the inner wall so that exhaust gas enters the mixer in a controlled flow through the exhaust gas inlet, through the cavity, and through the apertures into the chamber for mixture with ambient air.