GAS FLOW NOISE SUPPRESSOR Russian patent published in 2018 - IPC F01N1/00 

FIELD: machine industry.

SUBSTANCE: invention relates to machine building, particularly to noise suppressors. Suppressor incorporates a casing with an inlet and an outlet branch pipes, an installed coaxially to the casing hollow insert with a throttling element made from a porous noise absorbing material and a coil spring lined with sound absorbing material and placed between the insert and the body and forming a screw channel associated with the inlet pipe. Coils of the cylindrical helical spring in the axial section are made in the form of a rigid and perforated walls, between which there are two layers: a sound-reflecting layer adjacent to the rigid wall, and an acoustic-absorbing layer adjacent to the perforated wall, wherein sound reflecting material layer is made from complex profile composed of evenly distributed hollow tetrahedrons, allowing to reflect sound waves incident in all directions. Porous noise-absorbing material is used as the sound-absorbing material of cylindrical coil spring, having a bulk density of 500÷1000 kg / m³ and consisting of 100 pts. wt. of perlite with a particle diameter of 0.5÷2.0 mm, 100÷200 pts. wt. of one or more sintering materials and 10÷20 pts. wt. of binding materials.

EFFECT: higher efficiency of noise suppression.

1 cl, 2 dwg