There is provided an exhaust-gas aftertreatment arrangement for an internal combustion engine comprising a first catalytic converter, a second catalytic converter arranged in parallel with the first catalytic converter, the first and second catalytic converters being arranged to receive exhaust gas from an engine, a connection pipe fluidly connecting an outlet of the second catalytic converter with an inlet of the first catalytic converter, thereby allowing a flow of exhaust gas through the connection pipe, and an outlet valve arranged in the outlet of the second catalytic converter and downstream of the location of the connection pipe, wherein the outlet valve is configured to control a flow of exhaust gas through the second catalytic converter. There is also provided a method for controlling an exhaust-gas aftertreatment arrangement.

A hedge trimmer has at least one cutting blade and an internal combustion engine operatively connected to the at least one cutting blade so as to drive the at least one cutting blade reciprocatingly. The internal combustion engine has an exhaust gas muffler with an outlet for discharging exhaust gases from the exhaust gas muffler. A multi-part exhaust gas pipe is connected seal-tightly to the outlet of the exhaust gas muffler and connects the outlet of the exhaust gas muffler to an outlet opening where the exhaust gases exit from the hedge trimmer. The multi-part exhaust gas pipe has a plurality of pipe sections, including at least a first pipe section and a second pipe section, wherein the second pipe section is embodied separate from the first pipe section. At least one of the plurality of pipe sections is made of plastic material.

An automatic purifying device for engine exhaust gases is disclosed. Exhaust gases flow through a necked portion to be speeded and the temperature of the exhaust gases is kept uniform after entering an exhaust inlet, and the speeded exhaust gases then pass through a flared mouth so as to be diffused through metal catalyst carriers and a straight-through ceramic filter or wall-flow filter, allowing the poisonous emissions such as nitrogen oxides (NOx) to collide with the metal catalyst carriers to generate high heat to ignite carbon particles, carbon monoxide, hydrocarbons, and the like which are then decomposed and reduced to nitrogen gas and water by added urea or ammonia in the middle of passing through the straight-through ceramic filter or wall-flow filter, where the generated water can then be discharged through a drain port, thereby decreasing pollution to the environment.

A two-stage venturi cooler comprises a first tubular conduit having a longitudinal axis, the first elongate tubular conduit having an exhaust gas inlet at one end, a mixed gas outlet at an opposing end, and a cooling gas inlet, wherein structures inside the first stage define a venturi that forms a column of mixed gas, wherein the column of mixed gas comprises a ring of exhaust gas surrounding a core of cooling gas; and a second tubular conduit that is coaxial with the first tubular conduit, wherein the second tubular conduit has a mixed gas inlet at one end and a mixed gas outlet at an opposing end, and wherein the mixed gas inlet is to receive the column of mixed gas and to surround the column of mixed gas with an entrained column of ambient air.

Methods and systems are provided for a urea mixer. In one example, a urea mixer may include a plurality of outlets located adjacent a throat of a venturi passage.

An exhaust gas/reactant mixing assembly for an exhaust gas system of an internal combustion engine includes a mixing channel defining a longitudinal axis and extending in the direction thereof. A reactant delivery unit delivers reactant (R) into the mixing channel and an exhaust gas supply channel is arranged upstream of the mixing channel. The exhaust gas supply channel opens into the mixing channel at an opening channel region, wherein the opening channel region has at least two opening channel portions opening into the mixing channel.

Method and system for thermal regeneration of a catalyst by inlet turbine exhaust gas from a diesel engine, where a gas split stream (08) is led from the engine exhaust (02) through an eductor (04) and further to regeneration of a catalyst, wherein a cold air stream (09) is used to keep the regeneration gas stream at a desired constant temperature range.

The present invention relates to a manifold for receiving exhausts from a multi-cylindrical internal combustion engine. The internal combustion engine has such a firing order that the riser in the manifold receives exhausts from two cylinders during an overlapping stage, simultaneously via an inlet opening arranged upstream and from an inlet opening arranged downstream in the riser. The riser comprises a substantially constant cross sectional area, except in one area, which is located in a position in connection with the inlet opening arranged downstream of the two inlet openings, receiving exhausts simultaneously. Said area has a geometry facilitating receipt and flow of exhausts in the predetermined direction in the riser, on occasions when the two inlet openings receive exhausts simultaneously.

According to a first aspect of the invention, there is provides a turbo machinery assembly for an internal combustion engine, the turbo machinery assembly including: a bypass flow compensated Mass Air Flow (MAF) sensor for measuring the amount of intake air; exhaust gas or engine driven compressor operable to compress an input stream of air, the compressor having a compressed air outlet which branches into at least a first branch and a second branch; a first branch of said air outlet being connected to an engine, having a charge air cooler, with the second branch adding a secondary path and so as to enable said second branch of said air outlet to operatively control the intake manifold pressure and charge mass flow rate.

Methods and systems are provided for controlling and coordinating control of a post-catalyst exhaust throttle and an EGR valve to expedite catalyst heating. By closing both valves during an engine cold start, an elevated exhaust backpressure and increased heat rejection at an EGR cooler can be synergistically used to warm each of an engine and an exhaust catalyst. The valves may also be controlled to vary an amount of exhaust flowing through an exhaust venturi so as to meet engine vacuum needs while providing a desired amount of engine EGR.