TUBULAR COMBINED NOISE SUPPRESSOR Russian patent published in 2017 - IPC F01N1/04 

FIELD: machine engineering.

SUBSTANCE: suppressor consists of cylinder case, rigidly connected to the end inlet and outlet branches, the sound absorber, located between the case and perforated element and the acoustic transparent material, installed between the perforated element and the sound absorber. The sound-absorbing cylindrical insert is mounted along the axis of the suppressor; the conical-shaped air cowl is fixed at one of the perforated cylindrical insert end faces, and the cylindrical insert is fixed to the inlet and outlet branches by means of at least two stiffeners, located in the plane perpendicular to the suppressor axis. Inside the cylindrical insert there is the sound absorber and the acoustically transparent material, located between the perforated element of the insert and the sound absorber. The sound absorber is made in the form of the sound-absorbing element of annular type, which in the axial section is made in the form of the ring, which walls are made in the form of the rigid and the perforated walls, between which there are two layers: the sound-reflecting layer adjacent to the rigid wall and the sound-absorbing layer adjacent to the perforated wall. The sound reflecting material layer is made of the complex profile, consisting of the evenly distributed hollow tetrahedra.

EFFECT: noise suppression efficiency improvement.

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