RU2576690C1 - Kochetov(s spherical acoustic absorber - Google Patents

Abstract

FIELD: sound.

SUBSTANCE: invention relates to means for reducing noise in industrial and transport facilities. This is achieved due to the following: in spherical acoustic absorber containing both active and reactive type acoustic absorbers placed on a rigid frame, the frame consists of two parts; lower reactive part being made in form of spherical shape structure with internal congruent spherical resonant cavity formed by rigid spherical enclosure, equidistant to outer perforated spherical shell, connected with top active part that is made in form of rigid perforated cylindrical shell with perforated cover and solid base, at that cavity of cylindrical shell is filled with sound absorbing material, and connection of upper and lower parts of sound absorber is made by resilient damping element ensuring dampening of HF oscillations.

EFFECT: technical result is increasing efficiency of noise suppression at high frequencies by insertion volume cavities for Helmholtz resonators into sound absorber, which can improve efficiency at high frequencies.

2 cl, 3 dwg

Description

The invention relates to noise reduction in industrial and transport facilities.

Known designs of piece sound absorbers made in the form of volumetric parallelepipeds, cubic, conical, the cavities of which are filled with sound-absorbing material [1, 2, 3, 4]. Currently, fibrous sound absorbers are the most common in construction practice.

The disadvantages of the known piece sound absorbers are the relatively low efficiency at low and medium frequencies, and they do not meet the increased requirements for room design.

Known conical piece sound absorber according to the patent of the Russian Federation No. 22822004 [5], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with sound-absorbing material located inside the frame wrapped with mesh nylon fabric, the frame is made in the form of a cone attached to it the lower flange with a hemisphere also containing sound-absorbing material wrapped in a mesh nylon fabric or fiberglass, and filling with sound-absorbing material can be as with air cavities and located on the periphery of the hemisphere, as well as within it in a checkerboard pattern on the three coordinate planes.

Its disadvantage is the relatively low efficiency of sound attenuation at high frequencies due to the lack of sound-reflecting layers that perform sound insulation functions at high frequencies.

Known cylindrical resonant piece sound absorber according to the patent of the Russian Federation No. 23033679 [6], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with a sound-absorbing material located inside the frame wrapped in a mesh nylon fabric, the frame is made cylindrical in the form of a perforated round glass and lids, inside of which is located a central rod rigidly fixed to the axis of the glass, on which round partitions are mounted with the possibility of their fixation, inside one of which is a sound-absorbing material wrapped in a mesh nylon fabric.

The disadvantage is the relatively low noise attenuation efficiency at low frequencies due to the cramped dimensions for placing resonant cameras.

Known cubic piece sound absorber according to the patent of the Russian Federation No. 2334062 [7], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with a sound-absorbing material located inside the frame wrapped in mesh nylon fabric, the frame is made in the form of two cubic surfaces, one of which - the outer one is perforated, and the other inner one is acoustically transparent, and the sound-absorbing material wrapped in a mesh nylon fabric is located in the gap between the frame and which are interconnected by means of resonance inserts of different diameters, and the inner cavity is divided by a partition into two resonant cavities, one of which is filled with a sound absorber.

The disadvantage is the relatively low efficiency of sound attenuation at high frequencies due to the lack of sound-reflecting layers that perform the functions of sound insulation at high frequencies.

Known volumetric piece sound absorbers according to the patent of the Russian Federation No. 2354786 [8] and the Russian Federation No. 2485256 [9], consisting of a rigid frame suspended on a fastener to the ceiling of an industrial building, the frame is made with sound-absorbing material wrapped in an acoustically transparent material.

Their disadvantage is the relatively low noise attenuation efficiency at high frequencies due to the lack of Helmholtz resonators.

The closest technical solution in terms of technical nature and the achieved result is a piece sound absorber according to the patent of the Russian Federation No. 2485256 [10], containing a rigid perforated frame, inside which a sound-absorbing material is placed, the frame is made of the lower part of the conical shape with a cover and the upper part of the cylindrical shape, which is attached to the cover of the lower part of the perforated frame by means of a vibration damping pad, which allows damping high-frequency vibrations, while to the upper part is cylindrical about the perforated frame, the element is pivotally fixed by means of which the frame is attached to the desired object, for example, the ceiling of the production room, and the cavities of the lower and upper parts of the perforated frame are filled with sound-absorbing materials of different densities, and at least one sound-absorbing screw is located around the upper part of the cylindrical shape of the perforated frame piece absorber element made in the form of a cylindrical coil spring from a dense non-combustible sound-absorbing about the material.

The disadvantage of this piece sound absorber is the relatively low noise reduction efficiency at low and medium frequencies due to the lack of volume cavities for Helmholtz resonators and cavities filled with a sound absorber, i.e. absorbers of various densities.

EFFECT: increased efficiency of sound attenuation at high frequencies by introducing volume cavities for Helmholtz resonators into a piece sound absorber, which increase efficiency at high frequencies.

This is achieved by the fact that in a spherical sound absorber containing active and reactive sound absorbers placed on a rigid frame, the frame is made of two parts, while the lower reactive part is made in the form of a spherical shape with an internal congruent spherical resonant cavity formed by a rigid continuous spherical shell equidistant external perforated spherical shell connected to the upper active part, which is made in the form of a rigid perforated cylindrical d shell with a perforated cap and a solid base, the cavity being a cylindrical shell filled with sound-absorbing material, and the connection of the upper and lower portions of the absorber formed by elastic-damping element to damp high-frequency vibrations.

In FIG. 1 shows a diagram of a spherical sound absorber, FIG. 2 shows a diagram of a variant of a spherical sound absorber, front view, in FIG. 3 is a plan view of a spherical sound absorber, top view.

A spherical sound absorber contains active and reactive sound absorbers located on a rigid frame. The frame is made of two parts, while the lower reactive part 7 is made in the form of a spherical shape with an internal congruent spherical resonant cavity 8 formed by a rigid continuous spherical shell 6, an equidistant external perforated spherical shell 4 connected to the upper active part 1, which is made in in the form of a rigid perforated cylindrical shell 3 with a perforated lid and a solid base, and the cavity of the cylindrical shell is filled with sound-absorbing material, and the upper 1 and lower 7 parts of the sound absorber are connected by means of an elastic damping element 5, which allows damping high-frequency vibrations, while element 2 is pivotally attached to the perforated cover of the perforated cylindrical shell, by which the frame is attached to the desired object, for example, the ceiling of the production room.

The spherical resonant cavity 8 of the reactive part 7 of the frame is rigidly connected by at least one sleeve 9 with an axial hole that serves as the neck of the Helmholtz resonator, with an external perforated spherical shell 4, and the space between them is filled with a sound absorber.

A variant is possible (Figs. 2 and 3) when around the outer perforated spherical shell 4 of the reactive part of the sound absorber, in its horizontal diametrical plane, at least three cylindrical shells 3 of the active part 1 of the sound absorber are located.

Sound absorber spherical works as follows.

Sound waves propagating at an industrial or transport facility interact with a sound-absorbing material located in a cavity formed by a rigid continuous spherical shell 6, an equidistant external perforated spherical shell 4 connected to the upper active part 1, and also in the perforated cylindrical shell 3 of the upper active 1 parts that suppress noise at low, medium and high frequencies, respectively.

The connection of the upper 1 and lower 7 parts of the frame by means of an elastic damping element 5 allows you to damp high-frequency vibrations that can be emitted by a rigid frame, which allows it to be used to reduce noise on transport objects. Sound absorption at medium and high frequencies occurs due to the acoustic effect, built on the principle of the Helmholtz resonator, formed by an air spherical cavity 8 and the neck of the resonator 9, the diameter of which is selected in the desired sound frequency range to suppress noise in a given frequency band, as a rule: large volumes to suppress noise in the low frequency range, and small - in the medium and high frequencies. The interaction of sound waves with a screw sound-absorbing element 3 leads to noise attenuation in the high frequency range, and the implementation of a sound absorber from non-combustible materials makes the design fireproof.

Sources of Bibliography Cited in Patent Search

1. Kochetov O.S., Sazhin B.S. Noise and vibration reduction in production: theory, calculation, technical solutions. M .: MSTU im. A.N. Kosygina, 2001 .-- 319 p. (Fig. P. III. 10, p. 263).

2. Kochetov OS Textile vibroacoustics. Textbook for universities. M .: MSTU im. A.N. Kosygina, the group "Sauvage Bevo" 2003. - 191 p. (Fig. P. 2, p. 176).

3. Kochetov OS Laboratory workshop on industrial sanitation. Textbook for universities. M .: MSTU im. A.N. Kosygina, the group "Sovezh Bevo" 2004. - 168 p. (Fig. 6. 6, p. 120).

4. Kochetov O.S. Sound-absorbing structures to reduce noise in the workplace of industrial premises. The journal "Labor safety in industry", No. 11, 2010, pp. 46-50 (Fig. 1; p. 48 and Fig. 2; p. 48).

5. Kochetov O.S., Kochetova M.O., Khodakova T.D., Elin A.M. Conical piece sound absorber // Patent for invention No. 2282004. Published on August 20, 2006. Bulletin of inventions No. 23.

6. Kochetov O.S., Kochetova M.O., Khodakova T.D. Cylindrical resonant piece sound absorber // Patent for invention No. 2303679. Published on July 27th, 2007. Bulletin of inventions No. 21.

7. Kochetov O.S., Kochetova M.O., Khodakova T.D. Cubic piece sound absorber // Patent for invention No. 2334062. Published on September 20, 2008. Bulletin of inventions No. 26.

8. Kochetov O.S., Kochetova M.O., Kochetov S.S., Kochetov Sergey Sergeevich. Volumetric piece sound absorber // Patent for invention No. 2354786. Published on May 10th, 2009. Bulletin of inventions No. 13.

9. Kochetov O.S. Piece sound absorber // Patent for invention No. 2485256. Published 06/20/2013. Bulletin of inventions No. 17.

10. Kochetov O.S., Stareeva M.O. Piece sound absorber // RF patent for the invention No. 2495202. Published 10/10/2013. Bulletin of inventions No. 28.

Claims (2)

1. A spherical sound absorber containing active and reactive sound absorbers placed on a rigid frame, characterized in that the frame is made of two parts, while the lower reactive part is made in the form of a spherical shape with an internal congruent spherical resonant cavity formed by a rigid continuous spherical shell equidistant external perforated spherical shell connected to the upper active part, which is made in the form of a rigid perforated cylindrical bechiki with a perforated lid and a solid base, and the cavity of the cylindrical shell is filled with sound-absorbing material, and the connection of the upper and lower parts of the sound absorber is made by means of an elastic damping element that allows damping high-frequency vibrations, while the element is secured to the perforated cover of the perforated cylindrical shell by means of which to the desired object, such as the ceiling of the production room, and a spherical resonant polo be reactive part of the frame is rigidly connected to at least one bushing with an axial hole, performing the function of a Helmholtz resonator neck, with a perforated outer spherical shell, while the space between them is filled with a sound absorber. 2. A spherical sound absorber according to claim 1, characterized in that at least three rigid perforated cylindrical shells with a perforated cover and a solid base are located around the outer perforated spherical shell of the reactive part of the sound absorber, in its horizontal diametrical plane, and the cavity of the cylindrical shell is filled with sound-absorbing material.

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