INDUSTRIAL VACUUM CLEANER NOISE SILENCER Russian patent published in 2018 - IPC F01N1/00 

FIELD: acoustics.

SUBSTANCE: invention relates to the noise suppression equipment. Muffler contains a cylindrical body rigidly connected to the end inlet and outlet nozzles. In the body perpendicular to the direction of movement of the aerodynamic flow, at least two discs with openings are formed, forming chambers, wherein the discs orifices are alternately displaced relative to the housing axis so, that the holes in the two adjacent discs do not coincide, while the body is made of structural materials with a layer of soft vibration damping material applied on its surface from one or two sides. Coaxially cylindrical body in the chambers are sound-absorbing ring elements, in the axial section each of them comprises a frame made in the form of two outer perforated walls and an inner middle wall made in the form of a membrane resonant plate between which are arranged layers of sound absorbing material, the frame is made symmetrical with respect to the middle wall, which divides it into two congruent parts, each of which has three layers of sound-absorbing material, the more rigid first layers are made solid, profiled and fixed respectively on the outer perforated walls, the second layers, softer than the first, are discontinuous and are located with a gap in the focus of the reflective surfaces of the first layers, the latter are in the form of bodies of revolution in the form of cones connected by bases, and the first layers are made of a material with a sound reflecting coefficient greater than its sound absorption coefficient in the form of profiles of conical surfaces that focus the reflected sound on the second layers, and the third sound-absorbing layers are made of foamed sound-absorbing material in the form of a construction sealing foam and are located in gaps and voids formed between the first and second layers, wherein each of the outer perforated walls is rigidly connected to the corresponding second layer by means of vertical fastening elements perpendicular thereto, made in the form of plates, one end of which is rigidly fixed on outer perforated wall, and the second end is made in the form of clamps covering the rods respectively and tightening them with screws, while the rods are made parallel to the perforated walls, and the middle wall, made in the form of a membrane resonance plate, is rigidly connected to the frame by means of a construction sealing foam located in the gaps and voids of the frame.

EFFECT: higher efficiency of noise suppression.

3 cl, 2 dwg