HOUSING STRUCTURE FOR EXHAUST TURBOCHARGER

A casing treatment 4 including a recirculation passage 41 and a mixing piping 6 are provided. The recirculation passage 41 has a first recirculation opening 42 and a second recirculation opening 43 that are in communication with each other, the first recirculation opening 42 being formed inside a compressor housing 11 of an exhaust gas turbocharger and opening to an air passage 15 upstream of a compressor impeller 3, the second recirculation opening 43 being formed at the outer circumferential section of the compressor impeller 3. The mixing pipe 6 opens to the recirculation passage 41 and has a return opening 14 for introducing EGR gas and blow-by gas to the recirculation passage 41.