An engine exhaust system is accommodated in a counterweight portion without reducing either the efficiency of cooling by a radiator or the efficiency of purifying exhaust gas by an exhaust gas purification device. A body has a work device provided at the front and the counterweight portion at the rear. A ventilation path provided in the counterweight portion includes an elevated part formed between a bottom of a front portion and a bottom of a rear portion. The purification device and a muffler are disposed in the rear portion of the ventilation path so as to be positioned one above the other with the purification device lying above the muffler and having an upper portion protruding above the bottom of the front portion of the ventilation path. A windbreak plate made from a heat insulating material is disposed forward from the purification device so as to face the latter.

An engine-driven working machine capable of favorably reducing exhaust sound (that is, noise) is provided. An engine-driven working machine 10 is a generator in which an engine 15 and a muffler 67 are housed in an inside 13 of an outer case 12. The generator 10 includes a tail pipe 68 that is provided at a lower portion 67a of the muffler 67, a discharge port 37 that is disposed above the tail pipe 68, and a baffle plate 84 that is disposed to face the discharge port 37. The discharge port 37 is formed in the outer case 12. Further, cooling air that is sent from a cooling fan 17 is guided to below the muffler 67 with the baffle plate 84.

According to an embodiment of the present disclosure, an exhaust gas treatment apparatus may include: a preprocessor configured to primarily remove harmful substances from exhaust gas produced by combustion; and a postprocessor configured to further remove harmful substances from preprocessed gas, which is the exhaust gas from which the harmful substances have been primarily removed by the preprocessor, wherein the postprocessor may include a postprocessor housing having a preprocessed gas inlet through which the preprocessed gas is introduced and a postprocessed gas outlet through which postprocessed gas from which harmful substances have been further removed by the postprocessor is discharged and forming a flow path of the preprocessed gas therein, and a diffuser disposed adjacent to the preprocessed gas inlet and configured to diffuse the preprocessed gas introduced through the preprocessed gas inlet.

A valve assembly for an exhaust system of a vehicle. The valve assembly includes a first housing, a second housing, a valve flap and a spring. The first housing defines an inlet, an outlet, and an exhaust gas passageway in fluid communication with the inlet and the outlet. The second housing is attached to the first housing and defines a compartment. The valve flap is rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is allowed. The spring is disposed in the compartment and out of the exhaust gas passageway. The spring engages the valve flap to bias the valve flap toward the first position.

An engine muffler apparatus for reducing noise and pollution from small gas engines such as those on landscaping tools includes an outer housing having a central neck extension with a principal aperture extending through to an outer housing cavity. The neck extension is selectively engageable with an exhaust of a small gas engine. The outer housing cavity has a plurality of vent apertures. An intake extension tube and a medial tube are coupled to the outer housing cavity. The medial tube has a medial cavity. A first filtering medium is coupled within the medial cavity and filters pollutants passing therethrough. A second filtering medium is coupled within the outer housing cavity outside of the medial tube and dampens sound waves passing through the apparatus from the exhaust.

A muffler unit includes: an inner cylinder connected with a first exhaust pipe; a first outlet pipe that is connected with a downstream end of the inner cylinder and through which exhaust gas is discharged; an outer cylinder that houses thereinside the inner cylinder and defines, between the outer cylinder and an outer surface of the inner cylinder, an expansion chamber communicating with the second exhaust pipe; and a second outlet pipe that houses thereinside the first outlet pipe and defines, between the second outlet pipe and an outer surface of the first outlet pipe, a path connected with the expansion chamber to thereby be used for discharging the exhaust gas. Accordingly, there is provided the muffler unit having a size reduced compared with a configuration including two mufflers disposed in parallel with each other.

Provided is a gas exhaust apparatus for expelling a gas in a treatment space of a wafer treatment apparatus to outside, the gas exhaust apparatus including a main exhaust line connected to the treatment space, and an auxiliary exhaust line having an end connected to the main exhaust line to supply an external air current to the main exhaust line, wherein an automatic closer is disposed at another end of the auxiliary exhaust line to close the other end of the auxiliary exhaust line in a specific situation.

A multi-circuit system for temporarily connecting to a plurality of exhaust pipes of an oceangoing vessel at berth or at anchor and treating captured exhaust gas. Each circuit includes an exhaust gas processing system, a duct system to reach from the processing system to an exhaust pipe; a duct inlet port for attachment to a connector receiving exhaust gas from an exhaust pipe. A positioning system supports the duct systems and connectors in a ganged relationship and positions the duct systems and connectors in a temporary operational position and in a non-operational position. In another embodiment, blower controller is responsive to a pressure measurement at the duct inlet port or the connector to control a blower speed to set or maintain the pressure to a desired pressure.

In one aspect, a system is provided and includes an engine including an exhaust valve, an exhaust manifold downstream of the exhaust valve and a muffler downstream of the exhaust manifold. The system also includes a catalyst positioned downstream of the exhaust valve.

A heat management system for air-cooled engines suitable to power yard care equipment or vehicles. The system may generally comprise an engine, a blower configured to blow ambient cooling air across the engine, and an exhaust system comprising an exhaust header and a muffler. The exhaust header has an inlet end which receives heated exhaust gas from the engine and an outlet end fluidly coupled to the muffler. An air control baffle is configured to redirect a portion of the cooling air from the blower towards the exhaust header and the muffler to enhance cooling the exhaust system. The system may further include an outermost protective shield exposed to equipment operators and an inner heat barrier or shield located between the muffler and protective shield. The system is designed to ameliorate both radiative and convective sources of heat transfer to maintain the protective shield at temperatures below established industry standards.