RU2576688C1 - 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 is made of spherical shape with internal, congruent to frame, spherical resonant cavity formed by rigid spherical enclosure, equidistant to outer perforated spherical shell, the space between spherical covers being filled with sound absorbing material, and connection of external perforated spherical shell with an object, for example workshop ceiling, is made by the resilient damping element that can ensure damping of high-frequency oscillations and articulated with suspension, made in form of a rod, one end of which is connected with hinge installed on the elastically damping element, and other end is connected to the ring intended for its fixation on the object, and the spherical resonant cavity is rigidly connected with at least one sleeve with axial orifice that acts as neck of Helmholtz resonator, with external perforated spherical enclosure, and the space between them is filled with sound absorber.

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.

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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 a sound-absorbing material located inside the frame wrapped in a mesh nylon fabric, the frame is made in the form of a cone attached to its 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 like with air cavities located on the periphery of the hemisphere, and inside it in a checkerboard pattern along 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 the functions of sound insulation 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 glass and a round lid, 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 mesh nylon fabric.

The disadvantage is the relatively low efficiency of sound attenuation 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 a 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 the 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 to the 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 is located around the upper part of the cylindrical shape of the perforated frame a screw sound-absorbing element of a piece absorber, made in the form of a cylindrical helical spring from a dense non-combustible sound-absorbing th material.

The disadvantages of this piece of 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 spherical in shape with an internal congruent frame with a spherical resonant cavity formed by a rigid continuous spherical shell, an equidistant external perforated spherical shell, between which the shells are filled with sound-absorbing material, and the connection of the external perforated spherical shell with an object, for example p the ceiling of the production room, made by means of an elastic-damping element that allows damping high-frequency vibrations and pivotally connected to a suspension made in the form of a rod, one end of which is connected to a hinge mounted on an elastic-damping element, and the other is connected to a ring designed to fix it on the object, and the spherical resonant cavity is rigidly connected, with at least one sleeve with an axial bore, performing the function of the neck of the Helmholtz resonator, with an external her perforated spherical shell, and the space between them is filled with a sound absorber.

The drawing shows a diagram of a spherical sound absorber.

The spherical sound absorber contains a rigid frame made of a spherical shape with an internal congruent frame of a spherical resonant cavity 8 formed by a rigid continuous spherical shell 6, an equidistant external perforated spherical shell 4. In this case, the space 7 between the spherical shells 4 and 6 is filled with sound-absorbing material, and the outer connection spherical shell 4 with an object, such as the ceiling of a production room, is made by means of an elastic damping element cient 5 allowing to damp high-frequency vibrations, and is pivotally connected to the suspension 2, designed as a rod whose one end is connected with a hinge 3 mounted on the elastic-damping member 5, and the other connected to the ring 1, intended for fixing it to the object.

The spherical resonance cavity 8 is rigidly connected, with at least one sleeve 9, to an axial bore, which serves as the neck of the Helmholtz resonator, with an external perforated spherical shell 4, and the space 7 between them is filled with a sound absorber.

Sound absorber spherical works as follows.

Sound waves propagating at an industrial or transport facility interact with sound-absorbing material located in space 7 formed by a rigid continuous spherical shell 6, an equidistant external perforated spherical shell 4, suppressing noise at low, medium and high frequencies, respectively.

The connection 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 required sound frequency range for damping noise in a given frequency band, as a rule: large volumes for noise suppression in the low-frequency range, and small in the medium and high frequencies, and the implementation of a sound absorber from non-combustible materials makes the design fireproof.

Information sources

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 (1)

A spherical sound absorber containing active and reactive sound absorbers placed on a rigid frame, characterized in that the frame is made of a spherical shape with an internal congruent frame with a spherical resonant cavity formed by a rigid continuous spherical shell, an equidistant external perforated spherical shell, and the space between sound-absorbing material, and the connection of the external perforated spherical shell with an object, for example The production room is made by means of an elastic-damping element that allows damping high-frequency vibrations and is pivotally connected to a suspension made in the form of a rod, one end of which is connected to a hinge mounted on an elastic-damping element, and the other is connected to a ring designed to fix it on the object, and a spherical resonant cavity is rigidly connected, with at least one sleeve with an axial hole, which serves as the neck of the Helmholtz resonator, with an external rforirovannoy spherical shell, and the space between them is filled with a sound absorber.

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