LT6879B - Adjustable porous sound absorber - Google Patents

Abstract

The invention is intended to reduce reverberation time and echo cancellation in a variety of premises. The composite slurry for papermaking is embedded in the frame so that it can slide to the full depth of the frame. The principle of operation of the adjustable porous sound absorber is based on the physics of sound absorption and sound wave resonance of porous materials. As the sound wave falls into the absorber, part of the energy is absorbed into the composite plate of the papermaking sludge (3), the remaining sound energy passes through it, the diffracted wave dampens in the air gap (5) due to the sound absorption properties of the building (4). the same porous plate (3). Depending on the position (3) of the composite sludge composite board, the peak of sound absorption is at lower, higher or medium frequencies.

Description

Technical field

The invention relates to structures for absorbing sound.

State of the Art {various sound-absorbing structures are widely used means of improving sound quality in rooms.

Analogues of the present invention - air-borne sound-absorbing wall or ceiling panels are described in the United States Patent of 1980. No. US4347912A (Airborne-sound-absorbing wall or ceiling panelling). Porous sound absorber described in patent no. WO 2007073732A2 (Multi-layered porous soundabsorber), published in 2011 April 28 Also, a porous sound absorbing structure is described in United States Patent No. US8631899B2 (Sound absorber) published in 2010 December 9 No analogues were found in the Lithuanian Patent Office.

The first mentioned analog of the invention is a sound-absorbing structure that is widely used in construction. This construction consists of a perforated panel, a layer of porous material and an air gap to the building element (partitions or roof). This type of construction is widely used in auditoriums, corridors, waiting rooms, etc. This type of construction relies on sound wave resonances and sound absorption by porous materials. The disadvantage of such a structural system is that the sound absorption is in a relatively narrow frequency range.

The second mentioned construction analogue is described in patent no. WO 2007073732A2 works on the same principle as the above. This design is simpler than that described in United States Patent 1980. No. US4347912A. This construction differs from the above in that it does not have a perforated plate. The principle of operation of this invention is based on the sound absorption of the porous fibrous material and the air gap behind it. The disadvantage of the prototype is that the porous material is rigidly fixed, so there is no possibility to adjust the sound absorption of the absorber.

The third mentioned analogous construction is described in United States patent no. US8631899B2, which differs from the previous designs in that several different porous materials are used, but there is no air gap. The advantage of this type of construction, compared to the above, is that the total volume of the room is reduced. However, the overall sound absorption is lower compared to the previously mentioned analog constructions. Such construction requires a large amount of sound-absorbing materials to achieve effective sound absorption in the room.

The essence of the invention

The purpose of the invention is a sound absorber made of reusable materials, which would be based on effective sound absorption. The structure has the ability to be adjusted by changing the size of the air gap, thus the structure would become more universal compared to other created structures. It is proposed to use papermaking sludge composites as absorbent porous material. The composite panels are made on the basis of papermaking sludge (PGD), which is currently classified as waste, not suitable for reuse.

The adjustable sound absorber consists of:

Sliding papermaking sludge composite board, which is made of papermaking sludge and composite materials with slaked lime, clay or other binders.

The body can be made of wood panels, plastic composites, metal or other materials.

Description of drawings

The figures show views of an adjustable sound absorber where:

Fig. Adjustable sound absorber. Principle of operation and drawing.

Fig. Visualization of the structure in the room.

Description of the implementation of the invention

The invention is intended for use in the indoor environment of buildings, adapting to the purpose of the premises and essentially not changing the structure. The structure must be fixed on the internal walls or ceilings of the building. The porous papermaking sludge composite panel is pulled back or pushed against the building structure depending on the desired range of sound absorption, judging by the frequency response.

The principle of operation of the adjustable porous sound absorber

The operating principle of the adjustable porous sound absorber is based on the sound absorption of the porous material and the resonance of the propagating sound waves. When the sound wave (1) falls on the structure, part of the energy is reflected and part is absorbed by the papermaking sludge composite plate (3), which is fixed in the absorber body (2). The rest of the sound energy passes through it, the diffracted wave is attenuated in the air gap (5) due to the sound absorption properties of the air, and after being reflected from the building structure (4) and having lost some of the sound energy, it returns through the papermaking sludge composite panel (3) back into the room, having lost most of the energy . Since the sound absorption of acoustic sound absorbing systems is most effective at % wavelength, the air gap (5) behind the composite papermaking sludge plate (4) is adjustable so that the absorber can be applied to absorb a wider range of sounds. By using several or a dozen such absorbers with different air gaps (5) behind the porous papermaking sludge plate (3), a wide frequency range of sound absorption can be obtained.

Claims (3)

Adjustable sound absorber, characterized in that the active sound-absorbing plate made of paper-making sludge composite (3) is used, the device being adjustable t. i.e., increasing or decreasing the air gap (5) between the composite papermaking sludge plate (3) and the building structure (4). Adjustable sound absorber according to Claim 1, characterized in that the sound absorption frequencies of the device vary without changing the design. Adjustable sound absorber according to Claim 1, characterized in that efficient sound absorption over a wide frequency range can be obtained by using several or several absorbers in the room in the presence of an absorber system (using different air gap (5) distances behind the absorber plates (3)).