Kochetov plate-type noise suppressor with unified plates
FIELD: machine building.
SUBSTANCE: noise suppressor is designed for damping noise. The noise suppressor consists of a case of rectangular cross section rigidly tied with end inlet and outlet branches and of noise absorbing plates. The noise absorbing plates are arranged in the case at a certain step, forming flat channels in the case. Each noise absorbing plate contains perforated walls. A noise absorbing profiled layer is inserted between the walls; depending on density, the layer is either made as a solid element, for example by sintering or pressure moulding, or is composed out of two noise absorbing profiled layers. Each of these profiled layers is produced by alternating semi-spherical surfaces or surfaces of part of sphere so, as to facilitate alternation of continuous and air intervals between the perforated wall and the layer of noise absorbing material. Also the noise absorbing profiled layer at one perforated wall is a mirror reflection of the profiled layer at another perforated wall relative to symmetry line 0-0 of the continuous profiled layer. The layers merge to ensure location of a recess of one layer opposite to the recess of another and a projection of one layer opposite to projection of another.
EFFECT: increased efficiency of noise suppressing.
The invention relates to techniques reduce noise.
The closest technical solution to the technical essence is the silencer according to the Patent of Russian Federation №2305776, F01N 1/00, 1994, comprising a housing, inlet and outlet connections and the absorber (prototype).
The downside of it is relatively low effectiveness of noise control.
The technical result - increasing the effectiveness of noise control.
This is achieved by the fact that in a plate muffler, comprising a housing of rectangular cross section, rigidly connected with end inlet and outlet pipes, the sound-absorbing plate made of a skeleton containing perforated sheets, filled with material and located in the housing with a certain step, and forming it flat channels, each of the sound absorbing plate contains a perforated wall, between which is shaped sound absorbing layer, which is made either as a single unit, for example by a method of sintering or pressing depending on its density, or consisting of two profiled absorbent layers, each of which is obtained by rotation of the hemispherical surfaces or surfaces, consisting of part of a sphere, so that between the perforated wall and a layer of sound absorbing material were alternate is iesa solid, also the air spaces formed in hemisphere, with shaped sound absorbing layer one perforated wall is a mirror reflection of the profiled layer of the other of the perforated wall relative to the line of symmetry 0-0 holistic shaped layer made when merging layers so that depression of one layer was located against the depression of the other, and the protrusion of one layer was located against the ledge of another layer.
Figure 1 presents the scheme of the proposed muffler Assembly, figure 2 - diagram of the sound-absorbing plate filled with material, figure 3 is a section of the sound-absorbing plate.
Plate silencer (figure 1) includes a housing 1 of rectangular cross section, rigidly connected with end inlet and outlet pipes (not shown), the sound absorbing plate 2 made of a frame containing perforated sheets (not shown)filled with material and located in the housing 1 with a certain step And make it flat channels with a width A. the best modes of muffler occur under the following conditions: the ratio of the width of the housing of the muffler In to its height lies in the optimum range of values: N/=0,4...4,0; the ratio of the width of the casing of the silencer In his the length L lies in the optimum range led is in: B/L=0,53...2,0; the ratio of the height of the housing of the muffler H length L lies in the optimum range of values: H/L=0,33...2,0; the ratio of the width In1plates to the width of the housing of the muffler In lies in the optimum range of values:1/=0,05 0,5...; the ratio of the width And flat channels between the plates to the width of the housing of the muffler In lies in the optimum range of values: a/b=0,05 0,5...; width2flat channels between the plates and the body lies in the optimal range of values:2=0...A/2; the ratio of the area of free section F of the muffler to its length L lies in the optimum range of values: F/L=0.2/1000...0,2/1500.
This sound absorbing plate 2 (figure 2) is designed in such a way that the ratio of the width of the plate muffler1its height lies in the optimal interval greatness:1/N=0,1...0,8; the ratio of the width of the plate muffler1the length L lies in the optimum range of values: B1/L=0,1...0,54; the ratio of the height of the plate muffler N and the length L lies in the optimum range of values: H/L=0,5...1,0.
Case 1 muffler with pipes and sound absorbing plate 2 made of a frame containing perforated sheets, made of structural materials, coated on their surface with one or two sides of a layer of soft vibrationfree material, such as mastic VD-17, or material type "Guerlain-D", when this is the ratio between the thicknesses of material and vibrationfree coating lies in the optimum range of values: 1/(2,5...3,5).
Case 1 muffler and sound absorbing plate 2 made of a frame containing perforated sheets, stainless steel or galvanized sheet with a thickness of 0.7 mm with a polymeric protective and decorative coating type "Pural" thickness of 50 μm or "Polyester" with a thickness of 25 μm, or aluminum sheet thickness of 1.0 mm and a thickness of 25 μm. The ratio of perforation perforated sheets is equal to or greater than 0.25.
Each of the sound absorbing plate 2 (figure 3) contains the perforated walls 3 and 4, between which is shaped sound absorbing layer. To prevent rashes soft absorbers provided acoustically transparent material (not shown), such as fiberglass type EZ-100, located between the profiled absorbent layer and perforated sheets 3 and 4.
Sound-absorbing corrugated layer can be formed as a single unit, for example by a method of sintering or pressing depending on its density and consisting of two shaped sound absorbing layers 5 and 6, each of which is obtained by rotation of the hemispherical surfaces (or surfaces consisting of part of a sphere) so that between the perforated wall and a layer of sound absorbing material were striped with solid and air Ave is megucci 7 and 8, formed by a hemisphere. And shaped sound absorbing layer 5 of one of the perforated wall 3 is a mirror image of the profiled layer 6 at the other of the perforated wall 4 relative to the line of symmetry 0-0 holistic shaped layer made when merging layers 5 and 6 so that depression of one layer was located against the depression of the other, and the protrusion of one layer was located against the ledge of another layer. Moreover, the layers 5 and 6 can be attached to each other along the line of symmetry 0-0, for example with glue, i.e. made as adhesive bonding or received bilateral pressing as an integral profiled layer. As a sound-absorbing material, corrugated layer is either rigid porous sound-absorbing material, such as paralumino or cermets, or metalloprotein, or material based on aluminothermic alloys with subsequent filling them with titanium hydride or by air with a density in the range of 0.5...0.9 kg/m3with the following mechanical properties: compressive strength in the range 5...10 MPa, a bending strength in the range of 10 to 20 MPa, or soft mineral wool basalt type "Rockwool", or mineral wool of type "URSA", or basalt wool type P-75, or glass wool lined with glass wool material,or polymer foam, for example polyethylene or polypropylene, depending on the operating conditions of the muffler and the required characteristics of noise control.
Plate silencer works as follows.
Sound waves with a turbulent flow of compressed air received in the cavity of the housing 1 muffler and interact with the absorber plate 2. The design of the muffler is easy to manufacture and maintain. The transfer of sound energy into heat (dissipation, the dissipation of energy occurs in the pores of the material, which represents a model of cavities "Helmholtz", where energy losses occur due to friction oscillating with the frequency of excitation of the mass of air in the mouth cavity, the walls of the cap, having a form of an extensive network of pores of the absorber plate 2. The air gaps 7 and 8 increase efficiency reduce noise at low and medium frequencies, and running the profiled layers hemispherical profile of the sound-absorbing material increases the surface absorption and thereby increases the effectiveness of the jamming noise at medium and high frequencies.
Plate muffler, comprising a housing of rectangular cross section, rigidly connected with end inlet and outlet pipes, the sound-absorbing plate made of a skeleton, containing the his perforated sheets, filled with material, and located in the housing with a certain step, and forming it flat channels, the rate of perforation perforated sheets is equal to or greater than 0.25, and between the absorber and the perforated sheet is acoustically transparent material, and the ratio of the width of the housing of the muffler In to its height lies in the optimum range of values: N/=0,4...4,0; and the ratio of the width of the body of the muffler to its length L lies in the optimum range of values: B/L=0,53...2.0; a ratio of the height of the housing of the muffler H length L lies in the optimal range of values: H/L=0,33...2,0; and the ratio of the width B1plates to the width of the housing of the muffler In lies in the optimum range of values: B1/B=0,05 0,5...; and the ratio of the width And flat channels between the plates to the width of the housing of the muffler In lies in the optimum range of values: a/b=0,05 0,5...; and the width B2flat channels between the plates and the body lies in the optimal range of values:2=0...A/2; and the ratio of the area of free section F of the muffler to its length L lies in the optimum range of values: F/L=0.2/1000...0,2/1500, characterized in that each of the sound absorbing plate contains a perforated wall, between which is shaped sound absorbing layer, which is made either as a single unit, for example, the methodology is sintering or pressing depending on its density, or consisting of two profiled absorbent layers, each of which is obtained by rotation of the hemispherical surfaces or surfaces consisting of parts of the sphere so that between the perforated wall and a layer of sound absorbing material were striped with a solid, and also the air spaces formed in hemisphere, with shaped sound absorbing layer one perforated wall is a mirror reflection of the profiled layer of the other of the perforated wall relative to the line of symmetry 0-0 holistic shaped layer made when merging layers so that depression of one layer was located against the depression of the other, and the protrusion of one layer was located against the ledge of another layer.
SUBSTANCE: device contains casing, which allows inlet-pipe connection for air and exhaust branch for air and in inner space of which it is placed device for change of air direction, between inlet and exhaust branches for air it is located pass approximately vertically divide wall, which divide inner space for two chambers, separated by drain port.
EFFECT: compactness and small loses of pressure.
4 cl, 2 dwg
SUBSTANCE: box is designed for ventilation shaft of the subway. The box includes a headgear construction with air-conducting windows and external barrier in the form of ring-shaped shield. The shield is made in the form of cone widening upward and of amorphous material, and the inner surface of which is coated with a protective coating with sound reflecting inner surface. There is a through clearance between the shield and headgear construction.
EFFECT: sound reduction.
3 cl, 1 dwg
FIELD: instrument engineering.
SUBSTANCE: device, system and method aim at generation of column air flow. An air handling device comprises a body, an in-built driving wheel that generates downward air flow and in-built blades mounted in close proximity to the driving wheel at specified distance and serving to generate straight-line air flow. The device generates air flow that essentially holds column shape at the considerable distance. The method consists in generating air flow that essentially holds column shape at the considerable distance and is directed from ceiling to floor to mix air layers of air of various temperatures in an enclosed air space. Besides, the method consists that warm air directed from ceiling to floor accumulates thermal energy in floor, in devices being thereon and thereunder. If ceiling is colder than floor, accumulated energy is released.
EFFECT: reduced power consumption and noise level.
32 cl, 24 dwg
FIELD: heating systems.
SUBSTANCE: device is intended for air supply to the room and/or air discharge from the room. Device consists of the housing which has an air inlet and outlet and in the inner space whereof there provided is the air direction changing device. Housing consists of two covers which enclose the air direction changing device made in the form of a plate.
EFFECT: providing effective air supply to the room and/or air discharge therefrom.
12 cl, 3 dwg
FIELD: heating systems.
SUBSTANCE: invention refers to ventilation systems of rooms, and namely to natural plenum ventilation devices. Device consists of an air-intake branch pipe to be installed in the building wall opening and closed with an intake grid on the external edge. Device is equipped with an adjustable damper and filter. Device is equipped with the air pipeline connected to the air-intake branch pipe, and that air pipeline is installed along inner side of the building wall and located near the heating radiator or at least partially after the heating radiator. In the wall of the additional air pipeline there made is at least one air exhaust window or perforation supplying the air flow to the radiator, and adjustable shutter and filter is located in the additional air pipeline. In addition, the device can include a noise absorber. The latter shall be preferably installed in the additional air pipeline, and namely before adjustable shutter and filter as to air flow. Labyrinth-shaped noise absorber is preferable as well.
EFFECT: providing the possibility of heating the inlet air owing to air flow supply to the heating radiator.
5 cl, 1 dwg
FIELD: physics; heating.
SUBSTANCE: suppressor is intended for decrease of aerodynamic noise in air ducts of mechanical ventilation and air conditioning systems. Suppressor contains the body in cavity of which there are mounted acoustic dissipation elements pairwise contacting at inlet, forming tapering air passage channels and provided with convex fairings in contact points, as well as swing-out mechanism consisting of levers and control rods rigidly mounted at end faces of acoustic dissipation elements by washers and cotters.
EFFECT: higher efficiency of noise suppression within all the operation modes of ventilation and air conditioning systems.
FIELD: the booth is assigned for ventilation of the shaft of the Metro.
SUBSTANCE: the booth includes an above the shaft building with air passing windows and an external barrier in the shape of a ring-type housing. The housing is fulfilled in the shape of a expanding upwards funnel with sound reflecting surface. A hollow gap is between the housing and the above the shaft building.
EFFECT: reduces noise levels with the aid of a single element out of sheet material.
SUBSTANCE: ventilation pump comprises diaphragm pump, soundproofing chamber, and soundproofing inlet and outlet valves. According to the second version, the valve spaces are made of sound-absorbing chambers. According to the third version, the soundproofing check valves automatically shutoff the outer air duct when the signal from the external microphone exceeds a permissible level.
EFFECT: reduced noisiness.
FIELD: device for reducing noise at operation of plenum and exhaust ventilation systems, possibly used as separate units in ventilation chambers or built-in to air duct circuits.
SUBSTANCE: noise silencer includes housing restricted by walls and attachment members; zigzag air ducts formed inside housing by its walls and noise absorbing members. Air ducts inside housing are in the form of row of alternating different-height oblique-angle converging tubes and diffusers with converging and opening angles forming cyclically variable in cross section zigzag passages for air along width of housing at closing clearance through attachment members.
EFFECT: improved efficiency of noise silencing at low sound frequencies, uniform whole frequency effectiveness of ventilation noise silencer at reduced mass and dimension parameters.
1 dwg, 1 tbl
FIELD: reduction of noise from aerodynamic sources.
SUBSTANCE: noise silencer has internal tube with input and output holes; tube forms channel for passing air through. Tube is made of permeable shape-preserving fiber-porous polymer material, for example, of fiber-porous polyethylene or fiber-porous polypropylene. Tube is provided with airtight internal case made of galvanized steel sheet. Case is mounted to have gap relatively the tube and is filled with sound-absorbing material, for example, glass wool.
EFFECT: improved degree of noise reduction within standardized frequency spectrum.
21 cl, 7 dwg
FIELD: machine building.
SUBSTANCE: noise suppressor (version 1) consists of cylinder case (1). Porous insertion (2) in form of a truncated cone permeable for gas flow is installed inside the case. The smaller diametre of the truncated cone is on the side of flow inlet. There is formed central cavity (3) closed from the side of flow inlet and opened from the side of flow outlet. Porous insertion (2) with case forms circular channel (4) opened at inlet and outlet. Slotted blade vortex for swirling gas flow is set at channel inlet before porous insertion (2). Permeable circular insertion (9) made in form of tubular or slotted channels equipped with relief valves (10) is installed at outlet of circular channel (4); there are branches (11) of withdrawal of impurities separated from gas flow. Noise suppressing coating (12) is applied on external side of case (1). Also there is disclosed another version of suppressor.
EFFECT: increased reliability and resource of suppressor operation.
12 cl, 2 dwg
SUBSTANCE: invention relates to ventilation and is designed to reduce aerodynamic noise in the air ducts of the systems of mechanical ventilation and air conditioning. The device has a body equipped with a removable grid in the admission hole and having a convergent shape. There is a sound-absorbing material with a perforated screen adjacent to the body and the ratio of the diametres of the admission hole and outlet hole are in an optimum range of the values Dadmission/Doutlet=1.2÷1.4.
EFFECT: this structure provides for an effective muffling of noise in the dust-laden air flow environment while the system of ventilation and air conditioning is on.
SUBSTANCE: the invention relates to the technique of suppression of noise of compressor stations and boxes for gas-turbine engine testing. The multisectional silencer contains a base, into which an ejector is inserted perpendicularly to its axis, on the base, an equalising grid is located, connected with an adapter, on which a noise suppression unit is installed, consisting of separate sections connected in series; each of them is made of a layer of a noise suppression material with a thickness a, lined with perforated liner from the inside; the section consists of four subsections with a characterized size c, single noise suppression units are located with the set step b. The single noise suppression units consist of a hard frame designed as a cup in the profile, with a perforated side surface and a perforated bottom. In the upper part of the frame, a perforated lid is located. Inside of the frame, a rigidly fixed central rod is located, on which at least one internal partition is installed, with the possibility of fixing along the height of the central rod, forming resonance cavities between itself, the lid, and bottom of the cup; as a minimum, in one of them, noise suppression material is located, covered with acoustically transparent material. The perforation is slotted, and the coefficient of perforation of the side surface, the bottom, and the lid of the frame, and the internal partition is the same and equals 0.3 or more. The frame is made of the stainless steel or a galvanised zinc-coated sheet with a thickness of 0.7 mm, with polymeric protection decoration layer type made of Pural with a thickness of 50 mcm or Polyester with a thickness of 25 mcm. The technical result is increase in the noise suppression efficiency due to excluding the "ray effect" and noise waves penetration both along the axis of the silencer and through its walls by introducing sound absorbing materials on the acoustic wave propagation path.
EFFECT: increase in noise suppression efficiency.
3 cl, 3 dwg
FIELD: industrial acoustics.
SUBSTANCE: silencer comprises housing provided with hinged lid and filled with a sound-absorbing material set in the protecting shell. The housing is made of two concentric three-dimensional surface of regular polyhedrons. One of the surfaces is outer surface and is perforated, the other one is the inner surface and is solid. The sound-absorbing material is rolled with the acoustically transparent material and is interposed between the surfaces that are interconnected through at least two bushings.
EFFECT: improved silencing at intermediate and high frequencies.
1 cl, 1 dwg
FIELD: mechanical engineering.
SUBSTANCE: invention relates to silencing facilities for compressor stations and test boxes for gas-turbine engines. Proposed multisection noise silencer contains cylindrical base with straightening grid connected with adapter which carries noise absorbing unit consisting of separate successively connected sections, each being made of layer of noise-absorbing material, thickness "a" lines from inside with perforated envelope. Section consists of four subsections with specific size "c" which accommodate separate noise absorbers arranged at definite pitch "b". Separate noise absorbers consists of perforated skeleton with hanger. Skeleton is made in form of ellipsoid of rotation consisting of two identical and symmetrical surfaces fastened by at least three attachment members, and hanger is made in form of ring or hook. Skeleton is manufactured of stainless steel or zinc plated sheet, thickness 0.7 mm, with polymeric protective decoration coating type Pural, thickness 50 mcm or Polyester, thickness 25 mcm, or aluminum sheet, thickness 2.0 mm and thickness of coating of 25 mcm. Perforation is made slotted, and perforation factor is equal to or exceeds 0.3.
EFFECT: improved efficiency of noise silencing.
FIELD: mechanical engineering.
SUBSTANCE: invention relates to device s for silencing aerodynamic noise of pneumatic equipment and compressed gas or air exhaust systems. Proposed muffler contains intake branch pipe and housing rigidly coupled with branch pipe. Housing has lower and upper covers with grooves for fixing outer cylindrical bushing made of porous material. Covers of housing are interconnected by inner cylindrical bushing by means of screw engaging with threaded part of bushing. Calibrated holes, diameter d, are made in bushing, axes of holes being square to axis of bushing. Cylindrical cup-screen is attached to upper cover of housing outside outer bushing. Ratio of height B of bushing made of porous material to diameter D of intake branch pipe lies within range of optimum values B/D=5.5-7.5. Ratio of thickness b of outer bushing made of porous material to its height B lies within range of optimum values b/B=0.06-0.1. values of clearance s between outer bushing made of porous material and cup-screen lies within range of optimum values s=(0.05-0.2)xB. Outer cylindrical bushing is made of cerement, porosity degree lying within range of optimum values of 30-45%.
EFFECT: increased efficiency of noise silencing.