MULTI-SECTION NOISE SUPPRESSOR Russian patent published in 2015 - IPC F01N1/04 

FIELD: machine building.

SUBSTANCE: noise suppressor contains a cylindrical casing, end inlet nozzle rigidly connected with central pipe made with perforation. Between the casing and central pipe at least one perforated pipe is located. Pipes are located coaxially with possibility to create resonant cavities. Between the casing and perforated pipe, and in end part of the central pipe the sound absorbing elements are installed. Porosity of the sound absorbing element located between the casing and perforate pipe by 2.5…5.0 times is below the porosity of the sound absorbing element in end part of the central pipe. Sound absorbing elements comprise a smooth surface and a perforated surface between which a multilayer sound absorbing structure is placed and consists of three layers of sound-absorbing material.

EFFECT: increased efficiency of sound suppression.

2 dwg