Abstract: An emission reduction device which may be removably affixed to an engine's exhaust system. The device comprises a cylindrical carcass with a beveled opening in a diagonal line in its proximal part. A bobbin is affixed in the distal portion of the carcass. A cylindrical-shaped fibrous blanket may be inserted in the carcass and the fibrous blanket may be wrapped in a wire mesh. A second fiber mesh formed into a cone may be removably inserted in the cylindrical-shaped fibrous blanket with the larger diameter of the cone positioned proximally.

Abstract: An insert for sealing and acoustic damping of a longitudinal cavity having an interior surface, comprising: a) one or more carrier plates made of a polymeric material (A) which does not deform when heated to a temperature not higher than 180° C. and which comprises a main polymer (A1) which gives mechanical strength to the carrier plate, and—at least one vibration-damping polymer (A2), and b) a thermally expandable material (B). The vibration-damping polymer (A2) is preferably selected from the group comprising: thermoplastic polyurethanes, styrene/butadiene block copolymers, hydrogenated styrene/butadiene block copolymers, styrene/isoprene block copolymers, hydrogenated styrene/isoprene block copolymers, styrene/isoprene/styrene tri-block copolymers, and hydrogenated styrene/isoprene/styrene tri-block copolymers.

Abstract: An exhaust system composed of a plurality of components for an internal combustion engine for connecting to a manifold, the exhaust system includes at least one first section, which is provided indirectly or directly after the manifold in the flow direction, and a second section, which is directly adjacent thereto in the flow direction, wherein the two sections are connected to each other by a mechanical decoupling element. The resonant oscillations in the range above 600 Hz are to be attenuated in the exhaust system by more than 15 dB and, at the same time, the exhaust system is to be sufficiently rigid and self-supporting and designed to be lastingly gas-tight. For this purpose, a single-walled arid self-supporting acoustic insulating element is integrated in the exhaust system in the flow direction upstream of, or in, the first section.

Abstract: An acoustic attenuator 20 for an engine booster such as a turbocharger 10 for an engine 4 is disclosed in which the acoustic attenuator 20 includes an attenuator chamber 28 in which is located at least one absorption media 140. The acoustic attenuator 20 is located adjacent an inlet port of the turbocharger 10 so as to attenuate any acoustic pressure waves by dissipative reaction with the absorption media 140 before they have chance to reach other components of a low pressure supply system 50 for the engine 4.

Abstract: A silencer for an auxiliary power unit of an aircraft includes an inlet, an outlet, a housing, and a flow channel of a porous material, arranged in the housing. Between the housing and the flow channel an intermediate space is created, which space is divided by at least one outer partition into outer cells arranged around the flow channel. A central body includes a casing that is permeable to gas at least in some regions and that is arranged in the interior of the silencer. The central body includes inner partitions dividing the central body into inner cells. The resonance frequency of the inner cells corresponds to the natural frequency of the first radial mode in a channel formed between the central body and the inner surface of the inlet. In this manner particularly good sound attenuation is achieved with a compact installation space of a silencer.

Abstract: The present invention provides an acoustic attenuation based on sound ray deflection theory and a muffler. The method of the present invention provides a temperature gradient between the interior and the exterior of the chamber of the muffler through the low temperature refrigeration system, in which the temperature inside the pipe wall is higher than that outside the pipe wall. The said temperature gradient may deflect the acoustic ray towards the low temperature direction, so as to capture and reduce the noise.

Abstract: An apparatus and method to attenuate vibration and acoustic noise are provided. One apparatus includes a first layer formed from a non-metal material having a predetermined level of resistance to deformation to define a frequency response based on a vibrating frequency. The non-metal material has a profile defined by at least one sinusoid. The apparatus also includes a second layer defining an absorption layer coupled to the first layer. The second layer adds a body of mass adjacent the first layer.

Abstract: An exhaust silencer for the air conditioning system of an aircraft is disclosed.

Abstract: A fiberglass-binder insert is made by fabricating a shape-constant, cured fiberglass-binder mixture, into a shape-constant insert core, and shrink-wrapping the core while leaving exposed any bore which extends into the core. The core is fabricated by mixing fiberglass and uncured binder in a mixer, dropping the mixture into a conforming guide such as a funnel, and moving the mixture through the conforming guide and into a mold. A tamper can tamp the mixture to move the mixture from the conforming guide into the mold, and to distribute portions of the mixture vertically in the mold. Rotation of the mold effects circumferential distribution of the mixture in the mold. The mixture in the mold is heated to cure the binder, thus to establish a fixed shape of the resultant core product. A shrink film is shrunk about the core, providing apertures in the shrunk film at bore openings in the core.

Abstract: The present invention relates to an exhaust gas treatment unit for an exhaust system of a combustion engine, in particular of a motor vehicle, includes a housing, a plurality of exhaust gas treatment elements, which are arranged in the housing and through which a parallel flow is possible. The unit further includes an outlet nozzle, which penetrates a side face of the housing, and an outlet space disposed in the housing, whereby the outlet of at least one of the exhaust gas treatment elements opens into the outlet space. The rigidity and/or effectiveness of the exhaust gas treatment unit can be improved by means of a funnel body disposed in the outlet space, and comprising a funnel surface which is permeable to exhaust gas. The funnel body connects an outlet end of one of the exhaust gas treatment elements with the outlet nozzle.

Abstract: A compressor has first and second enmeshed rotors rotating about first and second axes to pump refrigerant to a discharge plenum. The compressor includes a muffler system comprising a sound absorbing first element and a sound absorbing second element. The second element at least partially surrounds the first element and defines a generally annular flow path portion between the first element and the second element At least one of the first and second elements comprises an expanded bead material.

Abstract: A muffler (1) for an exhaust system (2) of an internal combustion engine, especially of a motor vehicle, with a muffler housing (3), which encloses a housing interior space (5), and with at least one exhaust gas-carrying hollow body (4) with two half shells in a half shell construction. The hollow body is arranged in the housing interior space (5). The two half shells (14, 15) of the hollow body (4) are fastened to one another in the area of a separating plane (16). The assembly of the muffler (1) or of the hollow body (4) can be simplified if the two half shells (14, 15) are fastened to one another by fastening elements (17, 18), which are formed directly on the half shells (14, 15).

Abstract: The soundproofed exhaust duct for a turbine engine comprises a perforated inner shell defining a flow passage, and a solid outer shell, the inner and outer shells defining between them a space that is closed at the upstream and downstream ends of said space. A core extends between the inner and outer shells at a distance therefrom, and contains at least one sound energy dissipating layer made up of hollow beads that are held against one another. A frame with upstream and downstream portions connected together by longitudinal members supports the core and partitions it into a plurality of boxes that are filled with hollow beads that are held between perforated textures, the frame being secured to the outer shell and/or to the inner shell via at least one of its upstream and downstream portions.

Abstract: A flexible muffler for use in an aircraft environmental system includes a flexible body having a porous inner layer and an air impervious outer layer both supported by a helically wound adhesively attached reinforcing cord. The flexible body includes a pair of connecting end caps at opposed ends thereof which are joined to the flexible body in an air tight attachment. The resulting muffler provides acoustic energy absorptive and is readily flexed and bent to accommodate space restrictions within the environmental control system of the aircraft.

Abstract: A sound muffler combines a resonator chamber with a dissipative layer surrounding a through pipe. The muffler provides sound attenuation over a wide range of sound frequencies while maintaining unimpeded flow of gases through the pipe. This attenuation is achieved by combining dissipation with a frusto-conical resonant chamber. The dissipation is achieved by encircling the through passage with a layer of low density material such as metallic or ceramic foam or loosely packed fibers of a heat resistant material. The low density material attenuates the high frequency waves while permitting the passage of low frequency sound waves into the frusto-conical resonant chamber.

Abstract: A sound damper for compressed air systems of vehicles includes a housing, an insulator and at least one web. The housing has an air inlet and an air outlet. The insulator is located in the housing, and the web is located in the housing such that it protrudes at least partially into the insulator. Air that flows through the housing from the air inlet to the air outlet is conducted by the web into the insulator.

Abstract: A muffler for a vehicle includes a plurality of baffles fixed at a predetermined distance in a longitudinal direction of a muffler housing, an exhaust gas inflow pipe, an intermediate pipe, and a plurality of exhaust gas outflow pipes having an inlet thereof positioned in the same chamber defined by the adjacent pair of the baffles with the outlet of the intermediate pipe to considerably reduce exhaust noise, flow-induced noise, and booming noise of exhaust gas. The muffler is effectively protected from thermal damage of a vehicle by implementing a sound-absorbing heat-insulating material therein, and impresses consumers with dynamic, powerful, and polished image by making the exhaust gas outflow pipe in a dual type composed of first and second exhaust gas outflow pipes and disposing the outlet at the lower center of a rear bumper to be exposed to the outside, thereby considerably improving productivity of vehicles.

Abstract: A vehicle exhaust component includes an outer shell defining an internal cavity and at least one internal pipe located within the internal cavity. A wire tube surrounds the internal pipe and is spaced apart from the pipe by a radial gap. This radial gap is filled with a fiber material.

Abstract: A muffler for a vehicle may include a plurality of baffles to form a plurality of chambers, an exhaust gas inflow pipe having an outlet connected to one of the chambers inside the muffler housing through the baffles, an intermediate pipe disposed in parallel with the exhaust gas inflow pipe in the muffler housing through the baffles to fluid connect at least two chambers and a plurality of exhaust gas outflow pipes having an inlet positioned with an outlet of the intermediate pipe in any one chamber divided by the baffles and an outlet protruding outward through the muffler housing, without passing through the baffles, such that the exhaust gas passing through the intermediated pipe may be discharged outside the muffler housing.

Abstract: An exhaust system for a motorcycle is configured to enhance output while maintaining a necessary noise level. The exhaust system includes an exhaust pipe connected to an engine, and a silencer connected to the exhaust pipe. The silencer includes a hermetically sealed outer cylinder and an inner cylinder disposed within the outer cylinder so as to extend along an axis of the outer cylinder. The outer cylinder has a front end portion connected to the exhaust pipe and a rear end portion opened toward the atmosphere. The inner cylinder includes a reduced diameter portion with a diameter which becomes smaller in the downstream direction, a throttle portion with a constant diameter, the throttle portion being connected to the reduced diameter portion, and an enlarged diameter portion connected to the throttle portion with a diameter which becomes larger in the downstream direction.

Abstract: An attenuation device, particularly a pulsation attenuator, has a casing (1) defining a fluid chamber (11) through which a fluid may flow along a flow axis (7), and has an attenuation element made of a resilient material located within the casing (1). The attenuation element has at least two annular bodies (15, 17) that are disposed in an at least partially overlapping manner, surrounding the flow axis (7) at least partially.

Abstract: A muffler for a vehicle may include a plurality of baffles to form a plurality of chambers, an exhaust gas inflow pipe having an outlet connected to one of the chambers inside the muffler housing through the baffles, an intermediate pipe disposed in parallel with the exhaust gas inflow pipe in the muffler housing through the baffles to fluid connect at least two chambers and a plurality of exhaust gas outflow pipes having an inlet positioned with an outlet of the intermediate pipe in any one chamber divided by the baffles and an outlet protruding outward through the muffler housing, without passing through the baffles, such that the exhaust gas passing through the intermediated pipe may be discharged outside the muffler housing.

Abstract: According to the invention, it was recognized that the fiber products, in particular, glass fiber products, suitable for thermal insulation can be temporarily given: an inherently stable shape by fixing agents that can be activated. This enables the fiber molded parts produced from the fiber products according to the invention to be used more easily or fully automatically. Processing the fiber products to form a molded part becomes exceptionally simple if said product itself carries the fixing agents. Therefore, a fixing agent does not have to be added in a separate production step during the molding.

Abstract: A passive noise attenuation device and system is provided having a reticulated open-cell porous structure configured to acts as a passive control device in order to mitigate combustion noise and instability problems in combustion systems. A porous inert media structure is placed downstream of the reaction zone of a combustion chamber to dissipate noise and/or instability generated upstream in the flame. The porous inert media also limits and/or disintegrates vortical structures in the flame to produce a homogeneous flow field to facilitate distributed reaction zones.

Abstract: A fiberglass-binder insert is made by fabricating a shape-constant, cured fiberglass-binder mixture, into a shape-constant insert core, and shrink-wrapping the core while leaving exposed any bore which extends into the core. The core is fabricated by mixing fiberglass and uncured binder in a mixer, dropping the mixture into a conforming guide such as a funnel, and moving the mixture through the conforming guide and into a mold. A tamper can tamp the mixture to move the mixture from the conforming guide into the mold, and to distribute portions of the mixture vertically in the mold. Rotation of the mold effects circumferential distribution of the mixture in the mold. The mixture in the mold is heated to cure the binder, thus to establish a fixed shape of the resultant core product. A shrink film is shrunk about the core, providing apertures in the shrunk film at bore openings in the core.

Abstract: A composite structure and an associated exhaust washed structure are provided which may be formed of ceramic matrix composite (CMC) materials. A method of fabricating a composite structure which may include the CMC material is also provided. A composite structure may include a corrugated septum extending in a lengthwise direction. The composite structure may also include a flute within which the corrugated septum is disposed to form, for example, a partitioned flute assembly.

Abstract: A vehicular muffler is configured and arranged to smoothly introduce exhaust gas into a sound-absorbing material disposed inside of an outer case which has a plurality of relatively short inner sleeves therein. The muffler includes a porous plate which is disposed inside of the outer case, and which is connected to an exhaust pipe, and the porous plate is operatively connected to an outlet pipe which discharges an exhaust gas to the outside environment through an opening formed in an outlet side of the outer case. In one embodiment, the inner sleeves are arranged substantially parallel to each other, and are fluidly connected to a joint exhaust feed pipe disposed inside the outer case. The inner sleeves are connected to the outlet pipe on the outlet side of the outer case.

Abstract: According to the invention, at least part of the edge of the hole is loosely surrounded with a mesh structure so as to create a space between the latter and said edge part.

Abstract: A noise damper for a compressed air device includes a tubular housing part provided with an air inlet and an inserted insulating material, in particular, an inserted knitted fabric roll. The air inlet is embodied in the envelope of the tubular housing part such that the supplied air tangentially flows through the insulating material or the knitted fabric roll, is radially deviated inside the tubular housing part, and axially flows out from at least one end of the tubular housing part.

Abstract: An exhaust system includes a tubular inner shell for passing therethrough exhaust gases from a combustion engine, and a tubular outer shell enclosing the tubular inner shell and cooperating therewith to define a sound silencing chamber into which the exhaust gases are introduced. The tubular inner shell forms an inner peripheral wall of the sound silencing chamber, and an upstream portion of the inner peripheral wall is formed with a perforated wall area having a plurality of communicating perforations for communicating between an interior of the tubular inner shell and the sound silencing chamber, and a downstream portion of the inner peripheral wall has a non-perforated wall area having no communicating perforation defined therein.

Abstract: An exhaust device for a straddle type vehicle allowing a compact design while still satisfying the sound deadening characteristic requirements is provided. The exhaust device for a straddle type vehicle comprising: an exhaust pipe that is connected to an engine; a silencer that is connected to the exhaust pipe wherein the exhaust pipe is provided with a Helmholtz resonator, and the Helmholtz resonator is filled with a sound absorbing material. The Helmholtz resonator is formed with an opening that communicates with the inside of the exhaust pipe. The opening is formed in a place where the sound pressure in the exhaust pipe is high during the operation of the engine.

Abstract: An exhaust system for a straddle-type vehicle, such as a motorcycle, which achieves miniaturization and also provides a reduced noise output. The exhaust system is connectable to an engine of an associated vehicle and includes an exhaust pipe and a silencer. The silencer comprises an outer housing and an inner core accommodated in the outer housing. A sound absorbing material is arranged on an outer surface of a side wall of the inner core in a manner to come into close contact therewith. An air space is provided between an outer surface of the sound absorbing material and an inner surface of the outer housing.

Abstract: A compressor has first (26) and second (28; 30) enmeshed rotors rotating about first (500) and second (502; 504) axes to pump refrigerant to a discharge plenum (42). The compressor includes a muffler system (200) comprising a sound absorbing first element (232) and a sound absorbing second element (236). The second element at least partially surrounds the first element and defines a generally annular flow path portion (230) between the first element and the second element. A wall (250) at least partially surrounds the second element. A space (259) optionally containing a sound absorbing third element (261) surrounds the wall.

Abstract: The present invention provides composite muffler systems formed of a long fiber thermoplastic. Long fiber thermoplastic technology allows the fibers, to maintain a length sufficient to provide structural strength at lower fiber loading. The long fiber thermoplastic material for forming composite muffler systems also provides increased impact strength and creep resistance as well as chemical and thermal resistance. Mufflers molded with long fiber thermoplastics demonstrate improved dimensional stability as compared to known short fiber based moldings. One suitable muffler structure is a multi-piece muffler assembly including at least one long fiber thermoplastic shell section. In accordance with the present invention, the long fiber thermoplastic material and moldings may also be combined with over-molding of preforms of unidirectional or woven inlays, which provide local structural performance.

Abstract: An exhaust device for a straddle-type vehicle that satisfies the requirements of sound deadening characteristics and which has a reduced size is provided. The exhaust device for a straddle-type vehicle that includes an exhaust pipe connected to an engine and a silencer connected to the exhaust pipe. The silencer includes at least one resonator selected from a group consisting of a Helmholtz resonator and a side branch resonator. The resonator is packed with a sound absorbing material.

Abstract: The present invention relates to a muffler facia assembly including a muffler with at least one thermoplastic shell formed into a facia assembly on a motor vehicle. The facia may be any suitable body part of a motor vehicle, such as a bumper, a rocker panel, an air dam, a spoiler, a sideboard or a body module. An assembly in accordance with the present invention includes structural members to provide crash management features to increase the strength and impact resistance. In accordance with the present invention, the long fiber thermoplastic material and moldings may also be combined with over-molding of preforms of unidirectional or woven inlays, which provide local structural performance. The use of such preforms is particularly suited to use in the manufacture of high temperature, structural articles such as bumper muffler combinations.

Abstract: A muffling device has a muffling piece that is placed in an airflow path and muffles sound caused by airflow, and a drive unit that performs one of rotation and movement of the muffling piece.

Abstract: Provided is a sub-muffler which needs no heat resistant material such as SUS, and which can keep its durability and sound absorbing performance even when the sub-muffler is exposed to various corrosive components in the exhaust gas. At the same time, accomplished is a low-cost manufacture, which is a challenge that sub-mufflers and sound absorbing materials commonly face. Disclosed is a sub-muffler in which a perforated exhaust pipe is arranged, and caps and an out pipe are arranged outside the perforated pipe. Sound absorbing materials are filled in the space between the perforated exhaust pipe, and the caps and the out pipe. The sub-muffler is characterized in that, among the sound absorbing materials, at least part of the sound absorbing material of the perforated pipe side is a basalt fiber for high temperature.

Abstract: The engine exhaust system may allow scavenging of two-stroke engines using a retro-tube attached to an exhaust port of a two-stroke engine. Intake air may be obtained directly from environmental air at atmospheric pressure allowed by engine cycle operation and an approximately constant diameter retro-tube having a volume approximately equal to a swept volume of the piston movement.

Abstract: A delivery pipe includes an outer pipe, an inner pipe, and a noise emission decreasing device. The outer pipe is connected to a plurality of fuel injectors. The inner pipe is disposed in the outer pipe and has an open end through which an interior of the inner pipe communicates with atmosphere. The noise emission decreasing device acts so as to decrease a noise emitted from the inner pipe. The noise emission decreasing device includes a mesh, a porous member, a vibration suppressing member provided to the inner pipe, an elastic tube fitted into the inner pipe, or a wire harness inserted into the inner pipe.

Abstract: One embodiment of the invention includes a product including a fuel-cell exhaust diffuser; an air funnel; and at least two exhaust tubes attached to the diffuser.

Abstract: A sound insulation process comprises (a) providing at least one sound barrier comprising a substantially periodic array of structures disposed in a first medium having a first density, the array comprising at least one row of at least two of the structures, the structures being made of a second medium having a second density that is greater than the first density, the second medium being a viscoelastic medium, an elastic medium, or a combination thereof, and the first medium being a gaseous medium; and (b) placing the at least one sound barrier in at least one at least partially enclosed gas stream in a manner such that the row of structures extends in a direction that is perpendicular to the direction of flow of the gas stream.

Abstract: An air conditioning system, comprising: a channel to carry a flow of refrigerant, and a first noise reducer to change at least one property of the refrigerant as the refrigerant flows through the channel.

Abstract: An absorption muffler includes a metallic exhaust pipe including a plurality of perforations, a polymeric housing carried by the exhaust pipe and enclosing the plurality of perforations, and including axially opposed ends. Thermal insulation is carried radially between the exhaust pipe and the polymeric housing and axially between the axially opposed ends inclusive thereof. Acoustic insulation is carried between the thermal insulation and the polymeric housing.

Abstract: An apparatus and method for attenuating the sound generated by a single duct terminal unit in an HVAC (heating, ventilating, and air conditioning) system. The apparatus utilizes internal geometry to minimize noise due to air disturbances and aerodynamic effects within the apparatus.

Abstract: A silencer for a CPAP device comprises a housing assembly defining a flow path passing therethrough and including at least one of an inlet chamber, an acoustic chamber and a blower chamber. Each of the chambers has an inlet and an outlet for fluid communication therebetween. The silencer includes a combination of reactive components, resonators and dissipative elements disposed within the inlet, acoustic and blower chambers. The reactive component may be configured as a compliant-walled reactive tube. The resonator may be configured as a perforated plate defining a cavity volume. The dissipative element may comprise porous material substantially occupying the cavity volume bounded by the perforated plate in the chamber walls.

Abstract: A silencer includes a cylindrical member held between a body connected to an exhaust side of a fluid pressure device and a disk-shaped retaining member. A net-shaped sound absorber is disposed around an outer circumference of the cylindrical member. A pressure fluid flows from the body into the interior of the cylindrical member and is discharged toward the sound absorber through a plurality of first through fifth exhaust holes formed in the cylindrical member. Accordingly, dust in the pressure fluid is removed by the sound absorber, which is formed of a plurality of stacked filters, and further, the pressure fluid is discharged to the outside after exhaust noises have been absorbed by the sound absorber.

Abstract: A filter assembly for use with compressor assemblies such as oxygen concentrators, ventilators and other breathing apparatus including a compartmented housing member having at least one inlet opening, an outlet opening, a filter member, and an adjustment member associated with the at least one outlet opening for varying the size of the at least one outlet opening for adjusting the amount of ambient air entering the filter assembly.

Abstract: Silencer of exhaust gases, in particular for motor vehicles, comprising an inlet opening (13) and a cylindrical coat (1) provided with an outlet pipe (29) at its opposing end, said cylindrical coat (1) has an internal division into at least four working sections (5, 6, 7, 8) containing axially arranged elements, especially suppression elements, expansion chambers, a whirl chamber, resonators and twirling, deflecting, and accumulating elements, confined with at least three crosswise arranged partitions (2, 3, 4), while the cylindrical coat (1) opposite to the outlet tube (29) is provided with an inlet section (10) freely encompassing its first working section (5) provided with inlet holes (18) of exhaust gases, said inlet section (10) being attached to the surface of the cylindrical coat (1).

Abstract: A muffler structure capable of suppressing generation of abnormal noise in the muffler even when the outer and the inner tubes expand thermally. Provided is a double-pipe muffler structure including an inner tube and an outer tube. In the muffler structure, an annular front step portion and an annular rear step portion are formed in the inner tube, while the step portions is brought into contact, from inside, with the outer tube and thus are supported by the outer tube. The outer tube supports the front and the rear step portions by being brought into close contact with the step portions partially and elastically.