Abstract: A shroud assembly fixed to an abrasive blasting nozzle provides acoustic dampening during operation of the blasting system to reduce damage to the hearing of the user. The shroud assembly additionally provides features that improve safety and reduce fatigue during use. A first embodiment includes an end closure made up of flat acoustic panels and an alternate embodiment includes an end opening having peripheral chevron shaped acoustic panel edges. The shroud assembly includes a mechanism for attachment of the shroud to the abrasive blasting nozzle, a cylindrical blast column positioned forward from and coaxial with the blast nozzle, a cylindrical cone shell with at least one layer of acoustic dampening material surrounding and coaxial with the cylindrical blast column, a dead man switch handle, a second extended handle, a peripheral air curtain generator at the forward opening, and nested layers of one or more types of acoustic material(s).

Abstract: An intake manifold is for a marine engine having a throttle for controlling flow of intake air to the marine engine. The intake manifold has a plenum for receiving the intake air from the throttle, a plurality of intake runners which extends from upstream ends for receiving the intake air from the plenum to downstream ends for discharging the intake air to the marine engine, and a quarter wave resonator extending from an open end coupled to the plenum to a closed end, the quarter wave resonator having a tuned elongated cavity configured to attenuate sound emanating from the marine engine via the plurality of intake runners.

Abstract: The invention concerns a device (1) for attenuating intake noise and radiated noise that comprises an internal gas delivery conduit (2) linked to a combustion engine, the conduit (2) having a peripheral wall (23) on at least one portion of which there is disposed at least one element porous to air (4), sound attenuation means comprising at least one tube (3) disposed in the delivery conduit, at least one peripheral chamber (5) being delimited inside the conduit (2) between the tube (3) and the peripheral wall (23) of the conduit (2), the tube (3) comprising at least one portion having an opening (30) allowing the inside of the tube (3) to communicate with the peripheral chamber (5).

Abstract: Provided are a sound absorbing and insulating structure is configured to be placed in a sound wave propagation path to reduce noises, and a method of designing the sound absorbing and insulating structure. The sound absorbing and insulating structure includes: a back panel arranged along a sound wave propagation path and having a flat-plate shape; a plurality of rigid partitions spaced apart from the back panel and arranged at intervals in parallel with each other so as to form resonant spaces; and a fixation frame fixing the rigid partitions to the back panel.

Abstract: A semiconductor device fabricating apparatus includes a gas mixer having an upper surface and a lower surface, each of the upper and lower surfaces has an elliptical plane, and a side surface connecting the upper and lower surfaces, a gas inlet pipe on an upper portion of the gas mixer, and a gas outlet pipe on a lower portion of the gas mixer.

Abstract: A noise attenuation device for reducing resonance in a natural vacuum leak detector. The device includes a housing, a first connector connected to the housing, and a first fitting connected to the first connector. Also included is a second connector which is connected to the housing on an opposite end of the housing in relation to the first connector, and a second fitting connected to the second connector. A plurality of tubes is disposed within the housing between the first connector and the second connector such that air flows through the first fitting, the first connector, the plurality of tubes, through the second connector and the second fitting. A plurality of flow paths is created by the plurality of tubes, and the plurality of flow paths reduces the turbulence and the pulsation of air flow through the housing, reducing or eliminating resonance in the natural vacuum leak detector.

Abstract: A fluid pathway is provided with a flow controller in at least a portion of its length wherein the flow controller comprises an active surface capable of influencing the fluid flow through the fluid pathway, the configuration of the active surface conforming to at least one logarithmic curve conforming to the Golden Section.

Abstract: A device for transmitting engine sound into an interior of a motor vehicle includes a sound transmission line having a first end in acoustic communication with an air intake tract and a second end arranged to direct engine sound towards the motor vehicle interior. A sound transmitting porous media is arranged in-line with said sound transmission line and restricts airflow wherein the porous media such that airflow in the sound transmission line is required to pass through said porous media.

Abstract: An exhaust system for a vehicle features a pipe finisher including an inner sleeve. The inner sleeve has a reduced diameter portion spaced upstream from a downstream end of the inner sleeve. An exhaust pipe disposed in the inner sleeve, the exhaust pipe including a radially outward extending projection downstream of the reduced diameter portion of the inner sleeve.

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: 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: A tuned acoustic attenuation device includes a housing defining a chamber within with air inlet and outlet channels opening into the chamber. An acoustic chamber or chambers are arranged on an exterior wall of or alternately within the housing and positioned to extend in a substantially lateral parallel relationship to the inlet or outlet channel and are configured as quarter wave tuners. The acoustic chambers may be realized within the housing by adapting housing stiffening support ribs of the housing. The acoustic attenuation characteristics of individual acoustic chambers cooperate to broaden the sound attenuation bandwidth or increase the attenuation at selected noise frequencies.

Abstract: A flow diffuser for vehicles of the type having an engine and an exhaust pipe generally includes a substantially tubular body having an outer surface and a first end configured for attachment to an exhaust pipe. The flow diffuser further includes a diffusion portion including at least one channel having a root end located near the outer surface, an exit port, and a channel axis extending between the root end and the exit port, the channel increasing in flow area along the channel axis to reduce exhaust gas velocity.

Abstract: A venturi muffler is made of a plurality of metallic tubular stepped members which are stacked together and define at least one sound-reflective chamber which opens through an annular venturi passage into an axial flow passage of the venturi muffler thereby creating a partial vacuum in the annular chamber. The annular chambers include aligned openings through which exhaust gasses flow but are also reflected by walls of the sound-reflective chambers. Therefore, the exhaust sound or noise is dampened by the cancellation of sound waves 180 degrees out of phase with each other, the creation of a partial vacuum through which sound cannot propagate or propagates minimally, and by the heat removed by all of the metallic heat-conductive venturi-forming segments of the venturi muffler.

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: The invention relates to a sound absorber for an exhaust system having a Y-shaped feed piece arranged upstream from the sound absorber, combining two exhaust gas-carrying lines to form a single line entering into the sound absorber whereby the Y-shaped feed piece and the sound absorber are assembled from a common bottom shell and a common top shell. The invention also relates to an exhaust system equipped with the sound absorber.

Abstract: A device for attenuating energy along a conduit, comprising a first member having an essentially semi-cylindrical outer surface and a first cavity extending substantially longitudinally from end to end. A second member having an essentially semi-cylindrical outer surface is provided, with the outer radii of the first and second members being the same. The second member also has a longitudinally extending cavity. When the two members are secured to one another to form the device, the two cavities face one another to form a bore that extends from end to end and has respective opposed tapered portions having a circular cross-sectional configuration that decreases in diameter inwardly. The bore also has a central, cylindrical portion disposed between the tapered portions and having an axial length that is no greater than one third of the overall axial length of the device.

Abstract: An apparatus comprising includes a conduit portion having a conduit inner surface and a conduit outer surface, and a plurality of chambers in fluid communication with the conduit portion. The chambers include a first chamber defined, at least in part, by a first outer housing and a first chamber volume. The first chamber is in fluid communication with the conduit portion. A fluid is permitted to flow between the conduit portion and the first chamber through a first flow area. The chambers also include a second chamber defined, at least in part, by a second outer housing and a second chamber volume. The second chamber is in fluid communication with the conduit portion. A fluid is permitted to flow between the conduit portion and the second chamber through a second flow area. The first chamber volume is generally equal to the second chamber volume and the first flow area is greater than the second flow area.

Abstract: A tailpipe for use with a vehicle moveable in a forward direction upon a support surface and adapted to be oriented substantially perpendicular to the support surface. The tailpipe includes a windward surface facing in the forward direction and a leeward surface facing opposite the forward direction. The tailpipe also includes a tubular body defining a main exhaust gas flow passageway adapted to direct an exhaust gas flow from a proximal end to a distal end of the tubular body and a plurality of exhaust ports. The exhaust ports are disposed between the proximal end and the distal end of the tubular body and pass through the leeward surface for permitting at least a portion of the exhaust gas flow, when present in the tubular body, to exit the tubular body through the plurality of exhaust ports.

Abstract: A muffler that inhibits reduction in engine performance and reduces exhaust noise volume includes a conduit that passes through an expansion chamber. A partition wall is provided at a central section of the conduit. An upstream section upstream from the partition wall includes an outflow section that has a side surface in which outflow holes are formed that allow exhaust gas to flow out to the expansion chamber. A downstream section downstream from the partition wall has an inflow section that has a side surface formed with inflow holes that allow exhaust gas to flow in from the expansion chamber. An inner diameter of at least one section of the downstream section is smaller than an inner diameter of the outflow section.

Abstract: An exhaust pipe for an internal combustion engine includes an inner tube carrying a flow of exhaust gas and surrounded by an outer tube, with an insulating layer disposed between the inner tube and the outer tube. The inner tube has at least one region formed with a nub-shaped profile in contact with the flow of exhaust gas.

Abstract: A device for attenuating energy along a conduit, comprising a first member having an essentially semi-cylindrical outer surface and a first cavity extending substantially longitudinally from end to end. A second member having an essentially semi-cylindrical outer surface is provided, with the outer radii of the first and second members being the same. The second member also has a longitudinally extending cavity. When the two members are secured to one another to form the device, the two cavities face one another to form a bore that extends from end to end and has respective opposed tapered portions having a circular cross-sectional configuration that decreases in diameter inwardly. The bore also has a central, cylindrical portion disposed between the tapered portions and having an axial length that is no greater than one third of the overall axial length of the device.

Abstract: An acoustic silencer is provided by a tubular member extending along an axis and having a hollow interior defining an axial flow path therethrough. The tubular member has a sidewall with an interior face facing the hollow interior and having quarter wave resonators formed by blind holes therein.

Abstract: An apparatus for sonic coupling between an intake tract or engine compartment and a vehicle interior of a motor vehicle has a housing into which sound enters from the intake tract via a first line, and out of which sound exits into the vehicle interior via a second line. A transmission body is arranged in the housing, the transmission body having a gas-tight separating wall between a sound inlet into the housing and a sound outlet out of the housing. The position of the separating wall is held essentially constant by a positioning device. A transmission wall between the separating wall and the housing provides an acoutis transfer function that is adjustable. The separating wall runs generally perpendicular to the longitudinal axis of sound propagation and the transmission wall runs at an angle ? to the longitudinal axis of sound propagation.

Abstract: The present invention describes an automobile exhaust pipes, and more particularly to an exhaust pipe capable of producing appropriate pressure to assist engine torque output when the engine is running at a low speed and expediting the waste gas to be discharged from an automobile when the engine is running at a high speed, so as to enhance the operating performance of automobile engines.

Abstract: The present invention includes a power booster pipe suitable for attenuating sound associated with the intake or exhaust of an internal combustion engine and reducing pressure drop associated with movement of gases during operation of the engine. Generally, a diffuser portion is combined with an attenuation portion. One or more tubes of perforated material, such as steel and perforated flutes running the length of the tube increases the surface area of sound attenuating material exposed to combustion gases and the accompanying noise. The perforated flutes and tube can be encircled with sound reducing infill material. A low pressure drop design can be incorporated which includes a gradually increasing diameter tube utilized to route the combustion gases.

Abstract: An acoustic filter is provided with a single flow chamber for exposure of a flexible rubber layer to liquid undergoing flow through the flow chamber with noise producing acoustic energy therein. The flexible rubber layer is supported on a cylindrical drum with slanted holes therein through which the exposure to the liquid in the flow chamber is effected. An axially sectioned drum with dimensionally different diameters, radial thicknesses and slanted holes therein is positioned over the rubber layer within an outer casing to establish a plurality of gas-filled cavities of different axial lengths and separated from each other along the axial length of the liquid flow chamber which is connected at its opposite axial ends by pipe sections to a piping system from which the liquid within the flow chamber is derived.

Abstract: A fluid guideline with at least two structural elements made of substantially soundproof material has at least one opening for sound damping. An impedance change (in particular in the form of an impedance discontinuity) of the flow resistance of the fluid flowing through the fluid guideline is present between two adjacent structural elements, and the at least one opening is arranged in the region of the impedance change between two adjacent structural elements.

Abstract: A flow tube for an induction system with a turbo charger includes a first tube half and a second tube half with a noise attenuation plate positioned between the halves. The noise attenuation plate includes a plurality of holes having varying diameters and depths. The first tube half, the second tube half, and the noise attenuation plate are integrally formed as a single piece during an injection molding process. The noise attenuation plate is folding along a first living hinge to overlap one of the first or second tube halves. The other of the first or second tube halves is folded along a second living hinge to overlap the noise attenuation plate forming a flow tube that defines a flow path. The noise attenuation plate serves as a low pass filter that attenuates high frequencies while allowing lower frequencies through.

Abstract: A combined muffler and heat exchanger apparatus is provided. The apparatus includes a housing defining a heat transfer chamber and an acoustic attenuation chamber separated by a partition. A flow regulator and a fluid transport member are disposed within the heat transfer chamber. The flow regulator is adapted to regulate the flow of a first fluid, such as a heat source, between an input end of the housing and the partition. The fluid transport member is adapted to contain the flow of a second fluid. An acoustic regulator is disposed in the acoustic attenuation chamber and extends longitudinally from the partition to an output end of the housing. The acoustic regulator is a metal tube including a plurality of apertures adapted to attenuate exhaust stream acoustics associated with an automotive vehicle power source.

Abstract: A portable ventilator for providing an air-recipient with compulsory respiration is provided with an outlet manifold and a single-expansion-chamber muffler configured so that airflow through an inhale outlet port of the muffler is pulse-free and a transmission loss, defined as the ratio of sound power generated by the at least one compressor and incident on the muffler to the sound power transmitted by the muffler, is sufficient to deaden the sound power of the compressor.

Abstract: Exemplary methods, devices and/or system for reducing noise produced by a turbine, such as, a turbocharger turbine. An exemplary exhaust conduit employs material to absorb exhaust-borne noise and/or structure-borne noise. Another exemplary exhaust conduit employs features that dampen wall vibration.

Abstract: The present invention provides a noise attenuation assembly having at least one noise prevention pad disposed within an annular gap formed between a gas passage tube and an overlap tube. The noise prevention pad prevents the two tubes from coming in contact during thermal expansion of the tubes, and allows the tubes to contract without causing “tick and ping” noise, during a cool down.

Abstract: An exhaust muffler with a single-wall shell having a first end and a second end features a plurality of embossments formed on the shell and extending from the first end of the muffler to the second end of the muffler. The embossments are arranged in a pattern such that any straight line extending from the first end to the second end intersects at least one of the embossments, thereby imparting increased stiffness to the muffler shell. Each of the embossments preferably have an elliptical shape and are arranged in rows extending substantially parallel to a longitudinal axis of the muffler. The embossments in any given row are rotated ninety degrees from the embossments in preceding and succeeding rows and are spaced to provide an interlocking pattern.

Abstract: An improved exhaust system for an internal combustion engine generally comprises two expanding megaphones, separated by a dual core annular flow silencing section. The two or split megaphone design facilitates broadening of the time of the negative pressure wave to provide a desirable broad range power output while substantially reducing obnoxious sound output.

Abstract: A resistive muffler attenuates sound generated by the gas intake and suction valve during compressor operation of a refrigerant compressor. The resistive muffler is assembled inline with the suction gas flow of the compressor and is positioned within the compressor housing. The resistive muffler attenuates the sound generated by the compressor during its operation as refrigerant gas is drawn into the compressor from an evaporator and passes through the resistive muffler in transit to the suction valve and hence to the region of the compressor where the gas is physically compressed. The resistive muffler includes a muffler housing having an intake end and an exhaust end. An acoustic foam assembly is incorporated into the muffler housing.

Abstract: An absorptive and reactive muffler includes an annular flow path for the gas with the center of the annulus having a plurality of resonators which are in open communication with the downstream end of the annular flow path and make up the reactive portion of the muffler. The flow path is at least partially lined by an absorptive material overlain by a perforate material and makes up the absorptive portion of the muffler.

Abstract: An exhaust muffler with a single-wall shell having a first end and a second end features a plurality of embossments formed on the shell and extending from the first end of the muffler to the second end of the muffler. The embossments are arranged in a pattern such that any straight line extending from the first end to the second end intersects at least one of the embossments, thereby imparting increased stiffness to the muffler shell. Each of the embossments preferably have an elliptical shape and are arranged in rows extending substantially parallel to a longitudinal axis of the muffler. The embossments in any given row are rotated ninety degrees from the embossments in preceding and succeeding rows and are spaced to provide an interlocking pattern.

Abstract: Method and apparatus for damping resonance in a conduit (10) utilized for transporting exhaust gases from an internal combustion engine. The resonance is damped by virtue of the conduit (10) being provided with at least one perforation (14) located at a distance from the outlet end (11) of the conduit.

Abstract: Disclosed is a diffuser apparatus for facilitating a reduction in fluid pressure and suppression of noise. The apparatus comprises a tubular inner sleeve, a tubular muffler and a tubular outer sleeve. The inner sleeve defines a fluid flow axis and has a plurality of inner sleeve passages. The outer sleeve has the inner sleeve concentrically positioned therein and defines a plurality of outer sleeve passages. The muffler is concentrically positioned between the inner and outer sleeves such that fluid flows radially outwardly through the inner sleeve passages, through the muffler, and through the outer sleeve passages. The muffler may be spaced from the inner sleeve so as to define a gap between the muffler and the inner sleeve. The muffler may also be spaced from the outer sleeve so as to define a gap between the muffler and the outer sleeve.

Abstract: The exhaust sound and emission control system is a system for reducing sound and noxious emissions from an automotive exhaust. The system may have an exhaust resonator having one or more catalytic converter elements in combination therewith in a single device. Alternatively, the system may have multiple angularly disposed chambers therein, with a series of V-shaped baffles or guides in one of the chambers, thereby combining resonator and muffler functions in a single device. In another alternative, the system has a series of longitudinal tubes therein, in combination with a series of V-shaped guides or vanes, combining catalytic converter, muffler, and resonator functions in a single device. The various elements of the different embodiments, e.g. catalytic converter element(s), double wall shell, perforated tubes and multiple flow paths, interconnecting crossover tubes, etc., may be combined with one another as practicable.

Abstract: A bumper/muffler assembly is provided comprising a bumper; and a muffler having an outer shell. The outer shell may be formed from a non-high impact resistant material, such as a thin metal or a composite material. The muffler may comprise a separate element from the bumper, which is coupled thereto, or is formed as an integral part of the bumper.

Abstract: Disclosed is a diffuser apparatus for facilitating a reduction in fluid pressure and suppression of noise. The apparatus comprises a tubular inner sleeve, a tubular muffler and a tubular outer sleeve. The inner sleeve defines a fluid flow axis and has a plurality of inner sleeve passages. The outer sleeve has the inner sleeve concentrically positioned therein and defines a plurality of outer sleeve passages. The muffler is concentrically positioned between the inner and outer sleeves such that fluid flows radially outwardly through the inner sleeve passages, through the muffler, and through the outer sleeve passages. The muffler may be spaced from the inner sleeve so as to define a gap between the muffler and the inner sleeve. The muffler may also be spaced from the outer sleeve so as to define a gap between the muffler and the outer sleeve.

Abstract: An improved sound attenuating device for use in a gas transportation duct, said device comprising a core of acoustically absorptive material substantially enclosed within an impervious film to prevent direct contact between the acoustically absorptive material and gas flowing through said gas transportation duct, wherein said enclosed absorptive material is maintained in position between at least two perforated facing plates and further wherein there is provided between the perforated facing and the impervious film and between the impervious film and the acoustically absorptive material spacing means to allow unrestricted movement of the impervious film in the void between the perforated facing and the acoustically absorptive material, while preventing contact between the film and the perforated facing and between the film and the acoustically absorptive material, and blocking means to impede the internal flow of gas between the film and the perforated facing and between the film and the acoustically absorpti

Abstract: A reactive silencer intended for industrial supply air or exhaust air channels has a sound attenuator chamber (10), to which is fitted a partition wall (12) dividing the sound attenuator chamber into a first and second chamber part (14, 16). The partition wall (12) is fitted with two or more channels or pipes (26, 26′, 26″) which connect the first chamber part (14) to the second chamber part (16). In this way a silencer of small size and simple structure is obtained for attenuating noise, especially that produced by large or several small air channels.

Abstract: Systems and apparatus for degrading and cleaning combustion products of carbon-containing fuels such as fossil fuels. The systems and apparatus utilize catalytically reactive particles that are at least partially suspended by moving gases within a reaction chamber and maintained at a temperature sufficient to cause the suspended media particles, typically silica sand, silica gel, or alumina, to become catalytically reactive in the presence of moisture. Typically, the reaction chamber is maintained at a temperature in a range from about 30° C. to about 500° C. Moisture may be provided by the waste exhaust, although additional moisture may be introduced into the reaction chamber in order to maintain reactivity of the catalytically reactive particles. The systems and apparatus can be adapted to be used in combination with diesel engines or other internal combustion engines and industrial burners. The exhaust gases containing the incomplete combustion products can be further pressurized as needed.

Abstract: Systems and apparatus for muffling sounds produced by an internal combustion engine, and optionally catalytically degrading pollutants within waste exhaust gases. The systems and apparatus utilize a bed of particles within a muffling chamber. The gases are introduced using a diffusion tube with holes therethrough. The muffling particles preferably include silica or alumina, which can also catalytically degrade pollutants. Typically, the muffling/reaction chamber is maintained at a temperature in a range from about 50° C. to about 500° C., which is much lower than temperatures within conventional muffling systems for diesel engines. The muffling systems operate as substantially lower back pressure compared to conventional muffling systems. The systems and apparatus can be adapted to be used in combination with diesel engines or other internal combustion engines and industrial burners.

Abstract: An acoustic muffler for a turbine engine exhaust comprises an outer shell of tubular configuration, a tubular liner disposed within the shell, and a plurality of dividing walls extending between the liner and the outer shell so as to divide the generally annular space between the liner and shell into a plurality of chambers circumferentially spaced about the muffler. A central longitudinal axis of the liner is radially offset from the central longitudinal axis of the shell such that the chambers have different depths in a radial direction of the muffler, and the liner has at least one opening into each chamber. Thus, the muffler has a plurality of chambers of different sizes providing noise attenuation at a plurality of specific tuned frequencies, and the liner provides broad band attenuation.

Abstract: A muffler is constructed by inner and outer pipes, in which opposite end portions of the outer pipe are reduced in diameter, a welding portion of the inner pipe is accurately formed, and in this muffler, in order that a welding portion of the inner pipe can be accurately formed and that the outer pipe can be reduced in diameter uniformly over an entire periphery thereof to compress a buffer member uniformly over an entire periphery thereof, the inner pipe (2), having the buffer member (8) fitted on one end portion 2a thereof, is held within the outer pipe (1), held in position, in such a manner that a predetermined gap is formed between the inner and outer pipes (2) and (1). Subsequently, a diameter of the other end portion (1b) of the outer pipe (1) remote from the buffer member (8) is reduced, thereby fixedly securing this other end portion to the other end portion 1b of the inner pipe (2).

Abstract: Silencer for gas discharge device employing easily replaceable cartridge utilizing juxtapositioned layers of wire mesh and porous resilient material which dissipate the energy stored in an exhaust system and deflect under pressure of the exhaust gases to provide a self cleaning function and a cylindrical liner mounted within the cartridge comprising the same or larger wire mesh and wire diameter size than used in the cartridge for capturing the large particles of the exhaust gases before they pass through the layers of wire mesh forming the cartridge.