Patent ID: 7568340

Claim:
An internal combustion engine system comprising: an internal combustion engine comprising an exhaust manifold with an exhaust outlet and an intake manifold with an intake air inlet; a turbocharger comprising an exhaust gas turbine and a compressor, said exhaust gas turbine in fluidic connection with said exhaust outlet to receive exhaust gas; and an EGR mixer in fluidic connection with said exhaust turbine to receive exhaust gas and in fluidic connection with a fresh air inlet to receive fresh air for mixing with the exhaust gas, said EGR mixer comprising: an outer wall; an inner wall, said inner and said outer walls defining a cavity therebetween; a chamber defined within said inner wall; a plurality of apertures in said inner wall; an exhaust gas inlet disposed on said outer wall for receiving exhaust gas into said cavity then into said chamber through said apertures, said apertures increasing in diameter with respect to increasing distance from said exhaust gas inlet; wherein said inner wall and said outer wall are offset in relation to each other such that a distance between said inner wall and said outer wall progressively decreases from a point on the outer wall adjacent said exhaust gas inlet to a point on the outer wall radially opposite said exhaust gas inlet wherein the offset and the increasing diameters of said apertures act to moderate and optimize the flow rate of exhaust from said exhaust gas inlet to said chamber via said apertures; a fresh air inlet at a first end of said mixer for receiving air into said chamber for mixing with exhaust gas; and an air outlet at a second end of said mixer for the exit of a mixture of fresh air and exhaust gas; said EGR mixer in fluidic connection with said compressor so that said compressor receives a mixture of the fresh air and the exhaust gas; and said compressor in fluidic connection with said intake air inlet.