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: The present invention is directed to an improved dual phase muffler for the abatement of reduction of sound and emission pollutants such as hydrocarbons, carbon monoxide, and nitrogen oxides. More specifically, the muffler comprises a muffler casing, an inner chamber formed in the muffler, and a catalytically coated supported material contained within the inner chamber. The present invention is also directed to a catalytically coated metallic foam catalyst support, which optionally can be pre-coat with a metallic thermal arc sprayed layer.

Abstract: A fuel cell system with a muffler to reduce noise generated while supplying air to a fuel cells disclosed. One embodiment of the fuel cell system includes an air feeder to supply air; an electric generator to generate electricity through an electrochemical reaction between air and fuel; and a muffler provided in one end of the air feeder. The muffler includes a first pipe and a second pipe which are different in length from each other. The muffler has a relatively small structure, so that limitation in a mounting space can be decreased and a more compact fuel cell system can be realized. Also, even if there are considerable noise components at two or more frequencies, the mufflers corresponding to the respective frequencies are connected in series, thereby reducing the noise.

Abstract: A high-performance exhaust silencer in which a shell wall includes a shell outer plate, a shell inner plate, and a damping material to be inserted therebetween. A space between the shell outer plate and shell inner plate of the exhaust silencer is narrowed and the shell outer plate and the shell inner plate will not interfere with each other. An outer shape of the exhaust silencer is small but the expansion chambers are large by providing an air space between the shell outer plate and the shell inner plate. For the above-mentioned damping material, a material obtained by stretchably weaving metal wire into mesh is used.

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: A muffler for an exhaust gas system of an internal-combustion engine has an exhaust gas inlet and a first flow pipe arranged inside the muffler and completely penetrating the muffler. A shut-off device is arranged in the first flow pipe, for the shutting-off and opening-up an exhaust gas tail pipe which is situated downstream of the muffler and is connected with the first flow pipe. A second flow pipe partially penetrates the muffler, and has an overflow path between the first and second flow pipes situated inside the muffler. The first and the second flow pipes are connected with the exhaust gas inlet by way of a branching element and the shut-off device is arranged upstream of the muffler in the first flow pipe.

Abstract: To provide a muffler for a compact combustion engine, which is simple in structure and effective to sufficiently reduce the temperature of exhaust gases while avoiding contact with an external air, an exhaust guide passage 7 for communicating the exhaust gases (G) to a discharge port (63) is provided within an interior hollow of a muffler housing 6 defining an exhaust chamber (61) therein, and a side wall of this exhaust guide passage (7) is constituted by a portion (6W) of the muffler housing (6) and a duct wall (71) jointed to the muffler housing (6).

Abstract: A noise control apparatus for a motorcycle exhaust system. The apparatus includes at least one exhaust pipe assembly having a direct pass-through mode and an indirect mode wherein exhaust gases are optionally directed through noise attenuating means. The apparatus includes at least one valve for controlling exhaust gas flow, a motor, a switch controlling said motor, a wire carrier, a wire connected between the carrier and the valve(s), and a rotary threaded drive shaft driven by the motor for moving the positioner. The threaded drive shaft includes radially extending and circumferentially facing stop means on both sides of said wire carrier. The valve is positioned under the control of the switch.

Abstract: Method and device for a particle filter for an exhaust system for a combustion engine, wherein the filter is regenerated by spontaneous combustion of particles accumulated in the filter. Exhaust gases from the combustion engine are led, during operation, past the filter when the counterpressure in the exhaust gases which is caused by the filter exceeds a certain level. The invention also relates to a silencer in a vehicle which is driven by the combustion engine.

Abstract: The present invention relates to a silencer easily cleanable inside. This silencer comprises a casing cylinder and a segment member housed in the casing cylinder to constitute a sound reducing means. The silencer further comprises a segment member fastening means for fastening the segment member to the casing cylinder, a gas inlet-side lid plate with a punched hole, which closes an opening at one end of the casing cylinder, and a gas outlet-side lid plate with a punched hole, which closes an opening at the other end of the casing cylinder. At least either one of the gas inlet-side lid plate or the gas outlet-side lid plate is adapted to be detachable from the casing cylinder.

Abstract: The exhaust sound and emission control systems comprise a series of embodiments of devices 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 swept 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 pneumatic tool includes a shell with a chamber defined therein, a first passage communicated with the chamber and a second passage communicated with the chamber. A rotor is installed in the chamber for rotation when driven by pressurized air flowing into the chamber through the first passage. A shaft extends to the exterior of the shell from the rotor. A trigger is installed on the shell. A control device is put in the first passage and connected with the trigger for controlling the first passage. A muffler is put in the second passage. The muffler includes a plurality of balls.

Abstract: A muffler for coupling to an exhaust port of an internal combustion engine. The muffler includes a housing having an exhaust inlet configured to receive exhaust gas from the engine, at least one internal expansion chamber and an outlet opening. The muffler further includes a diffuser cover attached to the housing over the exhaust opening of the housing forming an exhaust outlet of the muffler. The diffuser cover forms a trap chamber, a restricted throat and an ejector portion. The ejector portion is configured to draw in ambient air through an air inlet to cool the exhaust gas as it passes through the exhaust outlet. The restricted throat is positioned downstream from said trap chamber and has a smaller cross-sectional area than said trap chamber so as to increases the velocity of the exhaust gas as the exhaust gas passes through the restricted throat and into the ejector portion so as to aid in drawing in ambient air.

Abstract: An object of the present invention is to provide a construction for exhaust emission control, which can prevent thermal deterioration in a catalyst and can heat exhaust gas to a catalyst activation temperature. In the present invention, an electrically heated catalyst portion 10 is provided in a separator 12a in a silencer 3 located at a distance from an engine. This electrically heated catalyst portion 10 heats low-temperature exhaust gas to a catalyst activation temperature. The exhaust pipe 11a branches into three pipes 22a, 22b and 22c in the silencer 3. The electrically heated catalyst portion 10 has a shape surrounding the each outer peripheral surface of pipe 22a, 22b and 22c of an exhaust pipe 11a. Exhaust gas is warmed to a temperature close to the catalyst activation temperature when it flows in the pipes 22a, 22b and 22c, and flows out of the pipe 22a, 22b and 22c.

Abstract: An arrangement having an auxiliary heater, a catalytic converter (12) for catalytic post-combustion of exhaust gas from the heater, a muffler (14) for damping of the noise caused by the exhaust gas, and an exhaust line for removing exhaust gas from the auxiliary heater. In order especially to devise an auxiliary heater in which the muffler and the catalytic converter can be installed relatively easily, the muffler (14) and the catalytic converter (12) are combined in sing module (10) that can be located on the exhaust line.

Abstract: A pneumatic tool includes a shell with a chamber defined therein, a first passage communicated with the chamber and a second passage communicated with the chamber. A rotor is installed in the chamber for rotation when driven by pressurized air flowing into the chamber through the first passage. A shaft extends to the exterior of the shell from the rotor. A trigger is installed on the shell. A control device is put in the first passage and connected with the trigger for controlling the first passage. A muffler is put in the second passage. The muffler includes a plurality of balls.

Abstract: In an exhaust emission control system for an engine, comprising an exhaust emission control catalyst disposed in an exhaust muffler whose inside is divided into a plurality of chambers, at least a portion of the inside of the exhaust muffler is divided into a first chamber for converting mainly NOx in exhaust gas and a second chamber for converting HC and CO in the exhaust gas. The exhaust muffler comprises: a partition wall having a conduit for guiding the exhaust gas from the first chamber to the second chamber; an exhaust gas inlet for introducing the exhaust gas into the first chamber; an external-air suction means for sucking external air into the second chamber; and a discharge pipe for discharging the external air and the exhaust gas flowing through the second chamber.

Abstract: A noise muffler for the exhaust of waste gases from apparatus such as an oxygen concentrator, including a muffler core with an inlet to receive the waste gases and a plurality of bores in the core first to direct the waste gases through a filter material and a cap enclosing the filter material and forming a plurality of outlets to direct the waste gases out of the muffler, the bores and outlets positioned to cause the waste gases to change their direction of flow multiple times before exiting the muffler.

Abstract: A silencer for a vacuum cleaner is provided and includes at least one hermetic expansion chamber mounted in an exhaust channel of the vacuum cleaner and allowing an exhaust airflow from the vacuum cleaner to pass through. The expansion chamber at its two sides has an inlet and an outlet connected to the exhaust channel. A silencing board is mounted in the expansion chamber, separating the inlet from the outlet. Pores are distributed throughout in the silencing board. The silencer integrates several different silencing structures together, and, when mounted to the exhaust port of the vacuum cleaner, can considerably diminish the noise generated by the vacuum cleaner in operation.

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: A muffler for equipment powered by compressed air, the muffler comprising a flexible muffler body formed from a sufficiently resilient material to resiliently deform under the influence of an exhaust air stream from an air motor, the body having an inlet and an outlet; a plurality of flexible baffles located within said body to muffle the sound of the air powered equipment; and an oil mist remover extending at least partially through said body, said oil mist remover being sized and shaped to prevent trapped oil from being re-misted by said exhaust air stream.

Abstract: An apparatus for modifying an exhaust stream of a diesel engine is provided. The apparatus includes a muffler arrangement having an exhaust inlet and an exhaust outlet in construct and arrange for sound attenuation therein. The apparatus also includes a catalytic converter arrangement positioned within the muffler arrangement between the exhaust inlet and exhaust outlet. During operation, the exhaust flow is directed both through the muffler arrangement and the catalytic converter arrangement, to advantage.

Abstract: A new and improved exhaust system as described herein, wherein the catalytic cartridge is selectively replaceable. The catalytic cartridge, which contains the catalyst, is located within the baffle tube. The baffle tube is easily inserted and removed from the housing assembly of the exhaust system, thereby making it simple and efficient to remove and replace the catalytic cartridge.

Abstract: The invention provides apparatus for treating a gas stream, notably a silencer assembly for use to treat the exhaust gasses from an internal combustion engine, which apparatus comprises a plurality of compartments within which one or more treatments are to be performed on a gas stream passing through the compartment, and through which the gas stream is to flow sequentially, characterised in that: a. At least two of said compartments each comprises a tubular body member containing or carrying a treatment element which is restrained against axial movement relative to the body member; and b. The tubular body members of the adjacent compartments are provided with radially outwardly and/or inwardly extending terminal flanges, at least some of which flanges provide a shoulder against which the opposing terminal portion of the adjacent compartment bears so as to form an axially extending structure comprising at least two compartments in axial or coaxial relationship to one another; and c.

Abstract: A gas expansion silencer comprising an endpiece for being connected to a source of gas under pressure, and a low-pressure stage comprising two cylindrical portions respectively of smaller diameter and of larger diameter, the smaller-diameter portion being connected to the endpiece and the larger-diameter portion having gas outlet orifices, the low-pressure stage being entirely filled with a porous metal packing.

Abstract: The present invention provides a noise muffler for the exhaust of a gas handling apparatus. The muffler of the present invention includes a muffler core having a central inlet and an integral flange. A cap engages the integral flange to form a chamber around the central inlet. The chamber is filled with a filter comprising woven polymer fibers such as a felt. A plurality of radial bores connect the central inlet to the chamber. The chamber includes a plurality of outlets remote from the radial bores.

Abstract: A permeable port constituted by an aperture and a porous member for covering the aperture is provided in a part of an intake air passageway portion of an air intake apparatus. The permeable port is disposed in at least a part of a region between the central position of the whole length of an air intake duct and the central position of the whole length of the intake air passageway portion.

Abstract: In order to provide a silencer (100), in particular an exhaust silencer, for an internal combustion engine, comprising a first housing (12) with an inlet aperture (E) and an outlet aperture (A), wherein an exhaust stream flowing into the inlet aperture (E) and escaping from the outlet aperture (A) is fed via a catalytic converter element (K), which silencer can be variably used for various internal combustion engines of different engine displacement, which silencer achieves low final temperature values, low sound values, and small pressure fluctuations and in addition allows a space-saving exhaust-flow guide arrangement through the silencer, it is proposed that a calming chamber (10) be provided between an outlet area (30) of the catalytic converter element (K) and the outlet aperture (A) of the first housing (12).

Abstract: The muffler includes a sound-absorbing structure (1A, 1B) having a gas introduced from a fuel cell (100). The muffler includes an outlet (13) defined by the sound-absorbing structure for discharging a drain separated from the gas.

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: A muffler for quieting the operation of a pneumatic tool. In one embodiment the muffler (630) is disposed within a volume defined by a peripheral wall (612) that receives an exhaust stream. An upper plate (631) having several open tubes (632) is disposed in the volume. Each tube is has an intermediate blocking plate (634). A plurality of sound-deadening panels (636) is disposed below the upper plate. The panels have apertures that slidably engage the tubes. A lower plate (650) is disposed below the tubes. The lower plate includes a plurality of apertures (657). One or more diffuser panels (652, 654) is disposed beneath the lower plate. An external exhaust vent (670) closes the volume. In operation, the exhaust enters the volume, is directed through the tubes, then into the sound-deadening panels, back into the tubes, and through the diffuser panels.

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 silencer for silencing and also for filtering exhaust gases, contains at least one acoustic resonator chamber (13, 14, 15, 16) (Helmholtz frequency), at least one porous body (7, 8) the porous body (7, 8) occupying at least part of the chamber and at least one connecting passage (17) for leading gas from each one of the acoustic chamber wherein the connecting passage (17) extend along the outher surface of the porous body, so as to lead along a helical flow path (19).

Abstract: An apparatus for modifying an exhaust stream of a diesel engine is provided. The apparatus includes a muffler arrangement having an exhaust inlet and an exhaust outlet in construct and arrange for sound attenuation therein. The apparatus also includes a catalytic converter arrangement positioned within the muffler arrangement between the exhaust inlet and exhaust outlet. During operation, the exhaust flow is directed both through the muffler arrangement and the catalytic converter arrangement, to advantage.

Abstract: A device to muffle and purify the exhaust gases from an internal combustion engine. A housing is divided into several chambers with the exhaust gases passing from one chamber to another, each successive chamber diverting the gas flow into an opposing direction. The first chamber is well insulated and contains a series of interconnected axial and equatorial tubes which provide multiple passageways with a large surface area which encourages repeated collisions of the gas molecules with the walls of the passages and with other molecules. While in this chamber the kinetic energy is greatly increased as is the temperature of the exhaust gases causing a break down of polluting molecules. Thereafter, the gases are directed alternately forward and rearward through several open chambers of increasing size which enable expansion and cooling of the gases and reduction of the associated noise. Finally the purified and cooled gases exit the last chamber into the atmosphere and pose no threat to the environment.

Abstract: A muffler is provided for use in a pneumatic hand tool having a handle with an exhaust passage. The muffler includes an inner tube, an outer tube, an upper plate, and an end cap. The inner tube is located within the outer tube, with one or more openings being provided in each. The upper plate is located near the inner tube and is provided to close off the exhaust passage so that a majority of the exhaust air is directed into the inner tube during use. The end cap attaches to the handle for closing off the exhaust passage, but for one or more exit openings. During use, exhaust air enters the inner tube, flows out its penguins, flows out the outer tube openings, and flows out the exit opening in the end cap. The tortuous path slows the exhaust air and assists in dampening exhaust noise.

Abstract: A muffler arrangement includes muffler elements arranged in rows which are oriented in each case transversely to a direction of flow. The muffler elements themselves are oriented in each case longitudinally in relation to the direction of flow. The distance between two adjacent muffler rows in this case amounts to approximately at least four times, or at least six times, the distance between two adjacent muffler elements of the equidistantly arranged muffler elements of a muffler row and/or the flow off edges of the muffler elements of at least one muffler row have guide plates. Equipping of the muffler elements of the last muffler row in the direction of flow may be dispensed with.

Abstract: A catalytic muffler has at least one reactor bed, each bed having an array of discreet adjacent flow zones. The flow zones are interconnected by a series of passages for unidirection flow of a gaseous fluid sequentially through each adjacent zone in turn from an inlet side of each reactor bed to an outlet side of the reactor bed. An inlet fluidly communicates with a first of the flow zones. An outlet fluidly communicates with the last of the flow zones.

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 muffler assembly, for use in the exhaust systems of vehicles or machinery using internal combustion engines, particularly piston or Wankel rotary types, consisting of either a square or round(ed) tube, with perforated baffles folded at angles, affixed within it.

Abstract: A catalytic muffler includes a housing having an inlet, an outlet, and a plurality of catalyst coated serially stacked perforated cups through which exhaust flows and is acoustically attenuated and catalyzed.

Abstract: A new and improved exhaust system as described herein, wherein the catalytic cartridge is selectively replaceable. The catalytic cartridge, which contains the catalyst, is located within the baffle tube. The baffle tube is easily inserted and removed from the housing assembly of the exhaust system, thereby making it simple and efficient to remove and replace the catalytic cartridge.

Abstract: An engine including a silencer in the exhaust passage thereof, wherein an exhaust gas flow passage pipe is arranged in the silencer body and a particulate filter is arranged inside the exhaust gas flow passage pipe. A first exhaust gas inflow-outflow opening and a second exhaust gas inflow-outflow opening of the exhaust gas passage pipe and an exhaust gas inflow opening to the silencer body are arranged at one end of the silencer body. The exhaust gas is selectively supplied to the first exhaust gas inflow-outflow opening, second exhaust gas inflow-outflow opening, and exhaust gas inflowing opening.

Abstract: A silencer for use with ultrasonic meters to reduce stray ultrasonic noise that could cause measurement inaccuracies. The silencer comprises a tubular body having at least two baffles spaced apart from one another. The baffles are preferably formed of an open-cell, reticulated metal foam material that absorbs noise in the ultrasonic range of frequencies under high-pressure operating conditions. The silencer is a reasonable flow conditioner and can be mounted directly to the meter without disturbing the flow.

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: An exhaust processor includes a housing formed to include an interior region and a partition or first spark arrester that partitions the interior region into chambers and includes a wool filter formed to include an opening. The wool filter is positioned to filter unburned carbon particles from combustion product generated by a vehicle engine. The exhaust processor further includes an outer conduit that extends through the opening formed in the wool filter and is formed to include a passage and an inner conduit that extends into the passage and is formed to include an opening through which unburned carbon particles flow from inside the inner conduit to impinge against the outer conduit so that the outer and inner conduits operate as a second spark arrester.

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: A process is provided for filling a muffler shell with fibrous material. The process comprises the steps of: providing a muffler shell comprising first and second muffler shell outer parts which define an internal cavity when coupled together and an internal structure adapted to extend at least part way through the shell internal cavity for defining at least one channel having one or more openings communicating with the shell internal cavity; placing a form over at least one of the internal structure and the first muffler shell part; drawing a partial vacuum through a first end of the channel; feeding fibrous material into the form while drawing a partial vacuum through the channel; removing the form after the fibrous material feeding step; and positioning the second muffler shell part over at least one of the internal structure and the first muffler shell part.

Abstract: An exhaust system for an internal combustion engine has special accommodations for preventing the pooling of water in the passageways of the exhaust system. One or more of the components of the exhaust system such as mufflers and or sections of exhaust tubing etc. have absorbent liners disposed at points within said exhaust system where water is likely to pool. The absorbent liners wick moisture away from the inner surfaces of the exhaust components in which they are disposed. Moisture is held within the absorbent liners until the temperature of the exhaust system rises enough to evaporate the moisture at which time the water vapor exits the exhaust system with the combustion products of the internal combustion engine. The absorbent liners are of a size and shape and are positioned within the exhaust system components such that they present minimal restriction to flow of combustion products through the exhaust system.

Abstract: The invention relates to an exhaust-gas muffler on an internal combustion engine in a motor chain saw. The exhaust-gas muffler includes a housing (1) which is assembled of two housing shells (2, 3). The one housing shell (2) has an exhaust-gas inlet (4) and the other housing shell (3) has an exhaust-gas outlet (5). An inner wall (8) as well as a catalytic converting element (7) are provided in the inner space (6) of the muffler housing (1). The catalytic converting element (7) is mounted between the exhaust-gas inlet (4) and the exhaust-gas outlet (5). In order to ensure an adequate catalytic converting treatment of the exhaust gas at low gas counterpressure, it is provided to divide the entering exhaust-gas flow (10) and to conduct at least one of these component flows (23) in contact with the catalytic converting element (7). The component flows (22, 23) are brought together and mixed with other before exiting from the muffler housing (1).