Gas flow noise suppressor

FIELD: machine industry.

SUBSTANCE: invention relates to machine building, particularly to noise suppressors. Suppressor incorporates a casing with an inlet and an outlet branch pipes, an installed coaxially to the casing hollow insert with a throttling element made from a porous noise absorbing material and a coil spring lined with sound absorbing material and placed between the insert and the body and forming a screw channel associated with the inlet pipe. Coils of the cylindrical helical spring in the axial section are made in the form of a rigid and perforated walls, between which there are two layers: a sound-reflecting layer adjacent to the rigid wall, and an acoustic-absorbing layer adjacent to the perforated wall, wherein sound reflecting material layer is made from complex profile composed of evenly distributed hollow tetrahedrons, allowing to reflect sound waves incident in all directions. Porous noise-absorbing material is used as the sound-absorbing material of cylindrical coil spring, having a bulk density of 500÷1000 kg / m3 and consisting of 100 pts. wt. of perlite with a particle diameter of 0.5÷2.0 mm, 100÷200 pts. wt. of one or more sintering materials and 10÷20 pts. wt. of binding materials.

EFFECT: higher efficiency of noise suppression.

1 cl, 2 dwg



Same patents:

FIELD: transport.

SUBSTANCE: proposed device comprises cylindrical case (1) with end front and rear covers (2) and (3), respectively. Said case (1) houses perforated cylindrical insert (4), aligned perforated inlet pipe (5) and outlet pipe (6), three crosswise webs (7), (8), (9), dividing said case into four chambers (10)-(13), adapter (14) and conical spreader (15). Basalt fibre (16) is arranged between case (1) and insert (4). Said webs (7), (8), (9) are perforated. Inlet pipe (5) is arranged in two chambers (10) and (11) while its perforation has five zones (17)-(21) and trapezoidal holes formed by tangential guise and round holes. Confuser adapter (14) is fitted inside outlet pipe (6) and connected with its inlet end by confuser larger base. Spreader (15) is arranged at inlet pipe (5) discharge end and directed there inside.

EFFECT: higher efficiency.

5 cl, 2 dwg

FIELD: transport.

SUBSTANCE: set of inventions relates to automotive industry. Mounting bracket for muffler support pipe is made of plate bent with formation of two support sides located in parallel planes and made with possibility to rest on opposite inner walls of side-member having U-shaped cross-section. The bracket contains attachment section to be mounted on muffler support pipe, and strut made capable to rest on bottom of side-member having U-shaped cross-section inside this side-member. The strut has V-shaped profile, where the central plane of branches is perpendicular to attachment section. Upper free edge of the first branch of V-shaped profile is rigidly connected with attachment section of Z-shaped profile. The other branch of V-shaped profile is made with possibility to rest on side-member bottom. Attachment assembly of exhaust system contains the said mounting bracket. The assembly contains L-shaped support pipe having free end made capable to be connected with muffler, and other end immovably connected with mounting bracket attachment section. Method for mounting the said exhaust system attachment assembly in side-member with U-shaped cross-section consists in containing steps in which free end of muffler support pipe is inserted into corresponding hole in side-member bottom. Exhaust system attachment assembly is given one quarter turn to position mounting bracket and pipe inside the side-member. Support sides come in contact with inner walls. The strut is accommodated at the bottom of side-member. Mounting bracket is fixed on side-member immovably connecting support sides with inner walls of the side-member.

EFFECT: lowering vibrations transferred to vehicle.

7 cl, 2 dwg

FIELD: machine building.

SUBSTANCE: acoustic electric noise silencer includes a housing, inside which an expansion chamber is formed. Inlet and outlet branch pipes are mounted on the chamber ends. The chamber is separated with a transverse partition wall into high-frequency and low-frequency noise reduction zones. A perforated pipe is mounted inside it and connects inlet and outlet branch pipes; noise silences housing is made from ferromagnetic material. Noise silencer housing is placed into a cylinder; with that, the cylinder is attached to a transport vehicle body, and noise silencer inside the cylinder is fixed by means of springs working for tension. A multiturn coil is applied onto (built into) a cylinder and its outputs are connected through a rectifying device (rectifying bridge) and a relay governor to a transport vehicle accumulator.

EFFECT: reduction of acoustic noise level and reduction of ICE energy losses caused by using known noise silencers.

1 cl, 2 dwg

FIELD: machine building.

SUBSTANCE: noise silencer includes at least one dissipative porous sound-absorbing module with fibrous or foamed open-cellular structure with a protective sound transparent layer that is located in a closed cavity of a load-carrying shell-type cover of the type of an expanding or resonator chamber, to which supply inlet and discharge outlet branch pipes are connected. Inside the branch pipes there located are separating tubular and/or separating plate-like partition walls that include bypass channels presented with perforation holes or cells of a meshy base. Porous sound-absorbing module is formed with separate granulated fragmented sound-absorbing elements. They are made of identical or different types and makes of sound-absorbing materials, with identical or different physical characteristics, chemical composition, porosity, quantity and combination of types of structures of porous layers consisting of one/or multilayered combinations, identical or different geometrical shape and overall dimensions that are mainly in dimensional range of 5…100 mm, which are made from initial utilised raw material in the form of porous sound-absorbing structures of utilised parts technologically processed by means of a crushing method, which are removed from utilised technical objects, mainly of parts of noise insulating packs of mechanical transport vehicles that have completed their life cycle, and/or from technological wastes and rejection of porous sound-absorbing materials and parts from them. As per the second version of a noise silencer design a porous sound-absorbing module consists of initial raw material made in the form of a corresponding semi-finished product of porous sound-absorbing structure of fibrous or open-cellular material, mainly of flat-leaved type, as a result of further technological crushing/cutting/chipping operations related to it. Peculiar feature of the third independent version of the structural design of a noise silencer is that structural composition of its porous sound-absorbing module is represented with the formed mixture of specified dosed combinations of separate granulated fragmented sound-absorbing elements obtained in the form of products of secondary recycled utilised processing of porous sound-absorbing structures of materials (applied as per the first independent claim of the invention), to the composition of which there added is certain quantity of separate granulated fragmented sound-absorbing elements of certain geometrical shape and overall dimensions (used as per the second independent claim of the invention).

EFFECT: improvement of sound-absorbing properties, environmental characteristics of a technical device, economic and ecological efficiency and practicability of use of the proposed technical device.

48 cl, 16 dwg

Cutoff silencer // 2472029

FIELD: machine building.

SUBSTANCE: cutoff silencer, lower and upper cylindrical hollow housings connected to each other, the lower of which includes a lower cover plate attached to it and covering some part of fastening elements, two side cover plates closing side openings made in side wall of lower housing, and upper housing includes an upper flange and an opening made in side wall of upper housing; at that, silencer has a pipe located in the opening of upper flange, which is put on the pipe; pipe is located in cavities of lower and upper housings of silencer and in the opening of bottom of upper housing; lower end of pipe is fixed above bottom of lower housing with a gap between them; upper end of pipe is located in the opening of upper wall of upper housing, which is connected to side wall of upper housing, under bottom of upper housing there located with a gap in relation to the bottom are at least two arc-shaped plates; at that, bottom of upper housing is provided with openings connecting the cavity of lower housing to cavity of upper housing; arc-shaped plates enclose the pipe on its opposite sides so that air gaps are formed between concave arc-shaped end surfaces of plates and external surface of pipe, and air channels are formed between adjacent straight-line edges of arc-shaped plates; at that, many radial openings located in cavity of lower housing are made in lower part of pipe.

EFFECT: reduction of sound level and improvement of silencer tightness.

FIELD: machine building.

SUBSTANCE: device is designed for damping noise in flow through channels. The sound absorbing flow-through channel device forms at least two flow through channels having an inlet orifice and an outlet orifice. The flow-through channels at least partially are restricted with three walls dissipating acoustic energy; the walls are formed with a package of the first, second and third sheets forming flow-through channels between them. Each of the said first, second and third channels is equipped with at least one lug and/or recess. The said lug partially enters the recess, so that the outlet orifice of the flow-through channel can not be visualised through the inlet orifice and vice versa.

EFFECT: additional dissipation of sound energy.

17 cl, 20 dwg

Silencer // 2396441

FIELD: engines and pumps.

SUBSTANCE: invention relates to machine building, particularly to development of devices designed to suppress noise propagating in aerodynamic channels. Silencer of, primarily, bypass turbojet engine blower, comprises channel 1, circular case 3, circular grid of sections 2 and perforated screen 7. Circular case 3 embraces channel 1. Circular grid of sections 2 is arranged in inner space of case 1. Air spaces between grid adjacent sections are communicated with spaces of case 3 and channel 1. Channel section is lined with noise absorbing structures 8. Perforated screen 7 separates circular case space from channel space. Degree of perforation of said perforated screen 7 makes, at least 25 %. Distance from outlet section of channel 1 to circular grid d makes at least, 0.1 of channel diametre. Distance h from circular grid 2 to aforesaid noise absorbing lining 8 of channel h makes at least 0.1 of channel diametre. Axial length of circular grid 2 does not exceed 0.1 of diametre of channel 1.

EFFECT: higher efficiency of noise suppression.

5 dwg

FIELD: machine building.

SUBSTANCE: noise suppressor is designed for suppressing noise of compressor stations and test boxes for gas-turbine engines. The noise suppressor consists of a cylinder frame made in form of a perforated bushing and of covers filled with sound absorbing material. A layer of acoustic transparent shell made out of capronic net or glass cloth is arranged outside the bushing. The frame is made of covers connected with the central rod with a perforated cylinder bushing consisting of two perforated shells - external and internal. Space between the shells is filled with sound absorber. Sound absorbing material inserted into the internal cavity of the sound absorber has higher porosity compared to sound absorber inside the shells and is made out of at least one profiled porous sheet. Profile of the sheet in cross section can be triangle, rectangular, trapezoid, in form of arcs of circumferences, or sinusoidal. Also in case of two or more profiled porous sheets they can be arranged both with gaps between them or without the gaps. Side closed surfaces of the shells can be round, as in cylinder shape, but also triangle, polygon, ellipsoidal or of any combination of these figures.

EFFECT: increased efficiency of sound suppressing at low and middle frequencies.

3 dwg

FIELD: machine building.

SUBSTANCE: noise suppressor consists of case with flap cover filled with noise absorbing material placed into protective casing. The case is made in form of side closed surfaces with a bottom and the flap cover. A hollow chamber out of perforated sheet is installed coaxially to the case and at equal distance from its internal surfaces. Surfaces of the chamber are congruent to surfaces of the case. A sound absorbing structure is located between the walls of the case and the chamber. The structure is made in form of perforated coaxial external and internal casings. The sound absorber is installed between these casings. The sound absorber is fabricated out of at least one shaped porous sheet. Profile of the sheet in cross section can be triangle, rectangular, trapezoid, in form of circumference arcs, or sinusoidal, while side closed surfaces of the case and coaxial casings of the sound absorbing structure in cross section can also have the shape of triangle, polyhedron, ellipse, circle or any combination of these figures.

EFFECT: improved acoustic properties in region of low, middle and high frequencies.

3 dwg

FIELD: machine building.

SUBSTANCE: noise suppressor consists of inlet branch and case out of porous material rigidly connected with branch. The case is made out of sound absorber in form of conic perforated coaxial external and internal bushings. A sound absorbing structure is installed between the bushings. The structure is made out of at least one shaped porous sheet. Profile of the sheet in cross section can be triangle, rectangular, trapezoid, in form of arcs of circles, and sinusoidal, while end surfaces limiting surfaces of a truncated cone are made out of porous material. Also porous casing in from of ellipsoid of rotation or porous spherical casing covers the case.

EFFECT: increased efficiency of noise suppressing.

4 dwg

FIELD: mechanical engineering; internal combustion engines.

SUBSTANCE: proposed exhaust system of internal combustion engine contains at least one unit of permanent joint of pipe of exhaust manifold with its fastening flange on member of housing of internal combustion engine. Flange is formed by casting of end section of pipe with metal alloy in mould. Metal alloy melting temperature is lower than melting temperature of pipe material and coefficient of temperature expansion of which exceeds coefficient of temperature expansion of pipe material and heat transfer coefficient of which is at least twice as great as heat transfer coefficient of pipe material. Flange and mating member of housing, for instance, cylinder head, are made of identical material, mainly of aluminum and/or magnesium alloy. Outer flanging is formed on end of pipe section filled with metal alloy, for instance, in form of conical bell whose input cut coincides with connecting plane of flange. Or end of pipe section filled with metal alloy is provided with ring or conical flanging dipped into flange so that inlet hole in flange coincides with inner channel of pipe. Also end section of pipe is made up of number of alternating in steps coaxial sections of different outer diameter, section of pipe with minimum outer diameter being arranged from side of flange. Moreover, end section of pipe is made conical so that thickness of wall of pipe in zone of inlet cut is 0.4-0.6 of thickness of cylindrical wall of pipe.

EFFECT: simplified design of device, improved reliability in operation.

3 dwg

FIELD: mechanical engineering; internal combustion engines.

SUBSTANCE: proposed muffler consists of housing divided by two partitions into intake, intermediate and outlet chambers, front and rear end face walls, intake and outlet perforated branch pipes whose inner cuts are arranged in intermediate chamber. Intake and outlet chambers of muffler are filled with sound-absorbing packing, and axes of perforated branch pipes are parallel to each other. Partitions are perforated and their surface is divided into faces, namely, central one and pass cross face with hole in central part through which intake or outlet perforated branch pipe passes, nonpass face and two peripheral faces, all adjoining central face. Pass cross face and adjoining peripheral faces are pointed to one side relative to central face, and nonpass cross face, to opposite side. Partitions are arranged in housing of muffler for contact of central faces of both partitions and they are orientated so that nonpass cross faces of partitions are arranged at opposite ends of muffler housing. Transition surface between pass cross and central faces is made to radius, and inclined projection is made on outer surface of central pointed to side of nonpass cross face.

EFFECT: improved efficiency of muffler.

3 cl, 8 dwg

FIELD: mechanical engineering; internal combustion engines.

SUBSTANCE: proposed exhaust muffler contains cylindrical housing with end face covers, coaxial intake and outlet branch pipes perforated and partially placed in housing, cross perforated partition with attachment installed in zone of inlet of end face of outlet branch pipe. Inlet branch pipe is arranged in intake resonating chamber, and outlet branch pipe, in outlet resonating chamber. Attachment is made in form of truncated cone whose smaller base is plate with hole in middle bent inside outlet branch pipe and secured on its end face, base is pointed to side of outlet of outlet branch pipe and its ends are bent to side of intake branch pipe and are connected with housing by welding. Attachment is provided with perforation. Cross partition and attachment divide housing into intake and outlet resonating and intermediate expansion chamber. Cross partition arranged between intake and expansion chambers is provided with perforation only at periphery, and said perforation is made with tangential guides of trapezoidal cross section arranged at angle of 30°, and perforation of intake branch pipe is provided with tangential guides of trapezoidal cross section arranged at angle of 24°.

EFFECT: reduced noise by 3-4 dBA.

8 dwg

FIELD: automotive industry.

SUBSTANCE: multisectional comprises cylindrical housing, face inlet branch pipe rigidly connected with the central pipe provided with perforation and defining at least one additional perforated pipe coaxial to the housing and central pipe. The faces of all pipes are rigidly connected with the housing via solid baffles. One of the baffles is secured to the inlet branch pipe, and the other one is mounted from the opposite side of the branch pipe. The first sound-absorbing member is interposed between the housing and perforated pipe. The second sound-absorbing member is set in the face section of the central pipe with the use of locking washer. The porosity of the first sound-absorbing member is lower than that of the second sound-absorbing member by a factor of 2.5-5.0.

EFFECT: improved silencing.

1 dwg

Muffler // 2282042

FIELD: mechanical engineering; engines.

SUBSTANCE: invention relates to developing and designing means of damping noise propagated along aerodynamic channels, particularly, along channels with flow having subsonic velocity, for instance noise of fan of aircraft double-flow turbojet engine. According to invention, noise damping in proposed muffler is provided by fitting housing of wall of double-flow turbojet engine enclosing the channel. Aerofoil cascade is arranged in housing space, and air volumes between neighbour profiles of cascade communicate with spaces of housing and channel. Aerofoil cascade can be installed in space of housing flush with channel wall, and width of aerofoil cascade can be made equal to height of housing, or aerofoil cascade can project inwards the channel behind the limits of housing space, and said cascade can be made in radial direction either radial or arranged at angle to radius of channel, and profiles of cascade in axial direction can be arranged parallel to axis of channel or at angle to axis of channel. Moreover, aerofoil cascade can be made with chord variable in height, variable maximum thickness and angle of profile bending.

EFFECT: increased range of noise damping, simplified design of muffler, reduced aerodynamic losses.

10 cl, 23 dwg

FIELD: mechanical engineering; internal combustion engines.

SUBSTANCE: proposed method of exhaust noise silencing with division of cycle portion into flows with subsequent discharge into atmosphere and ejecting of remnants of products from cylinder comes to the following: prior to opening of exhaust port by piston. Pressure of combustion products on cylinder is reduced by bypassing part of products from cylinder into bypass space by two synchronous flows. For this purpose first, part of combustion products is let out through hole opposite to exhaust port arranged at beginning of pre-exhaust sector-sector of mainly cross displacement of crankshaft journal and slowing down of axial displacement of piston to BDC, said part is divided into two semiflows into which jets of combustion products from following holes of pre-exhaust are fed in pairs in succession, and these semiflows are connected after exhaust port in flange of exhaust pipeline, and combustion products remaining in cylinder are fed into common flow after opening of exhaust port by piston. Two-stroke internal combustion engine consists of at least one cylinder with liner and piston moving in liner, piston being mechanically coupled with crankshaft, means for preparing working mixture and delivering it into cylinder, ignition and discharge of combustion products with means of scavenging, for instance, loop scavenging. Bypass space connected with exhaust port and flange of exhaust port and flange of exhaust pipeline is made on outer surface of cylinder over level of exhaust port. Cylinder and linear are provided with system of pre-exhaust holes communicating with space with at least one means for dividing combustion products bypassed into bypass space. Area of exhaust port is reduced by summary area of pre-exhaust holes owing to reduction of height of exhaust port.

EFFECT: improved exhaust noise silencing.

FIELD: mechanical engineering; internal combustion engines.

SUBSTANCE: proposed muffler has housing with cross-section width S=(2.5-12/0)d, cross-section height H=(0.401.0)S, length of housing L=(4.0-26/0)d, side walls, inlet branch pipe, diameter d, outlet branch pipe, diameter d, perforated shell 6, length L1=(1..0-0.2)L. Cross section of perforated shell is star-like, housing is divided by partition into chamber of length L1=(o.56-0.59)L and chamber of length L2=(0.41-0.44)L. Space between housing and perforated shell is filled up with sound absorbing material.

EFFECT: improved efficiency of noise damping in low-frequency and high frequency ranges of sound frequencies at low counterpressure owing to increased area of contact of noise waves with sound-absorbing material.

10 cl, 7 dwg

FIELD: mechanical engineering; internal combustion engines.

SUBSTANCE: invention relates to exhaust systems of internal combustion engines. Proposed multilayer filtering element made through for fluid medium consists of at least one outer layer made of partially porous material and provided with at least one edge section, and of at least one fibrous layer made on fibrous cloth. At least one outer layer forms envelope enclosing fibrous layer thanks to which said fibrous layer is reliably held is space formed by at least one outer layer 2. Such multilayer filtering element can be used for making filter for cleaning exhaust gases formed at operation of automobile internal combustion engines. Invention contains description of method of manufacture of said filtering element.

EFFECT: possibility of withstanding high thermal and dynamic loads in exhaust system of vehicle, cut down amount of hard particles in exhaust gases.

20 cl, 8 dwg

FIELD: processes and equipment for noise silencing.

SUBSTANCE: combination type noise silencer includes cylindrical housing rigidly joined with end inlet branch pipe and with outlet branch pipe; sound absorber arranged between cylindrical housing and perforated member; acoustically transparent material arranged between perforated member and sound absorber. Sound absorbing cylindrical insert is arranged along axis of nose silencer. On one end side of perforated cylindrical insert cone shaped deflector is mounted. Cylindrical insert is secured to inlet and outlet branch pipes at least by means of two rigidity ribs arranged in plane normal to axis of noise silencer. Sound absorber is arranged inside cylindrical insert. Acoustically transparent material placed between perforated member of insert and sound absorber is also arranged inside said cylindrical insert.

EFFECT: improved efficiency of noise silencing.

7 cl, 2 dwg

FIELD: processes and equipment for noise suppressing, possibly noise silencers.

SUBSTANCE: noise silencer includes housing in the form of corrugated tube having inlet and outlet openings; insert arranged with gap relative to inner surface of housing and having shape similar to that of housing. In zones of minimum surface area of cross section of gap perforated rings are mounted. Said rings are made of rigid porous sound absorbing material such as foamed aluminum, cermet or metallo-porolon or shelly stone with porosity degree in range of optimal values 30 - 45%. Surfaces of gap are covered with sound absorbing material in the form of plate of basalt base mineral wool or mineral wools of other types or basalt wool or glass wool faced with glass felt or foamed polymer such as polyethylene or polypropylene. Sound absorbing material is faced along it whole surface with acoustically transparent material such as glass cloth or "Poviden" type polymer.

EFFECT: improved noise suppressing efficiency.

2 dwg