KOCHETOV'S PIECE NOISE KILLER Russian patent published in 2015 - IPC F01N1/04 F01N1/08 

FIELD: engines and pumps.

SUBSTANCE: claimed device comprises noise absorbing element including outer and inner perforated walls with three plies of noise-absorbing material arranged there between. First, more rigid, ply is shaped and solid and secured at outer perforated wall. Second ply, more soft than the first one, is discrete and located at the focus of noise reflecting surfaces of the first ply and shaped to solids of revolution shaped to balls and ellipsoids of revolution. Note here that first ply is made of material with noise reflection factor higher than its noise absorption factor and shaped to spherical surface channels interconnected to make a single dome-like channel to focus reflected noise to second ply. Third noise-absorbing ply is made of foamed noise-absorbing material as a construction sealing foam to be arranged in cavities between first and second plies.

EFFECT: efficient noise suppression in low and average frequencies.

5 cl, 3 dwg