A secondary air system for an aircraft engine comprises an air flow path communicating between a source of pressurized cooling air and an air consuming component. A filter is disposed in the air flow path upstream from the air consuming component. The filter has at least one of: openings of a size selected for capturing suspended particles; and a filter surface material for binding with chemical contaminants.

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.

In one aspect, an aspiration system for a work vehicle includes an exhaust tube extending along a flow direction from an upstream end to a downstream end. The exhaust tube defines an exhaust passage extending from the upstream end of the exhaust tube to the downstream end of the exhaust tube. The exhaust tube includes a venturi portion. The aspiration system also includes an aspiration tube in flow communication with the venturi portion and configured to receive an aspirated airflow. The system further includes a flow adjustment mechanism provided in operative association with venturi portion such that the flow adjustment mechanism is configured to adjust a cross-sectional flow area of the venturi portion of the exhaust tube.

A filter element has a filter medium folded in a star shape that surrounds annularly a longitudinal axis of the filter element and is flowed through radially from exterior to interior. The filter element has a primary air passage and a secondary air passage. In the filter medium, a cutout is formed that penetrates a plurality of folds of the filter medium. A passage socket at which the secondary air passage is formed extends through the cutout. An air filter provided with a filter housing having a raw air inlet, a primary air outlet, and a secondary air outlet, has such a filter element that separates in the filter housing a raw side communicating with the raw air inlet from a clean side. The primary air outlet communicates through the primary air passage and the secondary air outlet through the secondary air passage with the clean side, respectively.

A filter element has a filter medium folded in a star shape that surrounds annularly a longitudinal axis of the filter element and is flowed through radially from exterior to interior. The filter element has a primary air passage and a secondary air passage. In the filter medium, a cutout is formed that penetrates a plurality of folds of the filter medium. A passage socket at which the secondary air passage is formed extends through the cutout. An air filter provided with a filter housing having a raw air inlet, a primary air outlet, and a secondary air outlet, has such a filter element that separates in the filter housing a raw side communicating with the raw air inlet from a clean side. The primary air outlet communicates through the primary air passage and the secondary air outlet through the secondary air passage with the clean side, respectively.

A secondary air system for an aircraft engine comprises an air flow path communicating between a source of pressurized cooling air and an air consuming component. A filter is disposed in the air flow path upstream from the air consuming component. The filter has at least one of: openings of a size selected for capturing suspended particles; and a filter surface material for binding with chemical contaminants.

In one aspect, an aspiration system for a work vehicle includes an exhaust tube extending along a flow direction from an upstream end to a downstream end. The exhaust tube defines an exhaust passage extending from the upstream end of the exhaust tube to the downstream end of the exhaust tube. The exhaust tube includes a venturi portion. The aspiration system also includes an aspiration tube in flow communication with the venturi portion and configured to receive an aspirated airflow. The system further includes a flow adjustment mechanism provided in operative association with venturi portion such that the flow adjustment mechanism is configured to adjust a cross-sectional flow area of the venturi portion of the exhaust tube.

In one aspect, an aspiration system for a work vehicle may include an exhaust tube extending defining an exhaust passage therein. The exhaust tube may include a venturi portion, with the exhaust tube further defining an aperture within the venturi portion of the exhaust tube. The system may also include an aspiration tube configured to be coupled between the exhaust tube and a separate component of the work vehicle. The aspiration tube may define an aspiration passage extending between the separate component and the exhaust tube. The aperture defined by the exhaust tube may fluidly couple the aspiration passage and the exhaust passage. Furthermore, the system may include a restrictor body positioned within the exhaust passage. As such, the restrictor body and the venturi portion may be configured to adjust a flow parameter of exhaust gases flowing through the exhaust passage.

A proactive heating system for a vehicle, which is used to increase the temperature of an exhaust catalyst prior to ignition of an engine to reduce emissions. The proactive heating system is part of an exhaust system for a vehicle, and includes an electrically heated catalyst and an air pump, which are activated prior to engine ignition, to increase the temperature of a three-way catalyst such that the three-way catalyst is at the desired target threshold temperature, or light-off temperature, prior to engine ignition, eliminating the delay in emissions treatment after cold-start of the engine. The proactive heating system addresses the high level of untreated emissions emitted from an internal combustion engine before the catalytic emissions system reaches the light-off temperature. The proactive heating system provides heating of a catalyst to light-off temperature without combusting hydrocarbon fuel, which leads to engine out emissions.

An exhaust gas aftertreatment system includes a first decomposition chamber, a first dosing module, a first conversion catalyst member, a second decomposition chamber, a second dosing module, a second conversion catalyst member, and a third conversion catalyst member. The first decomposition chamber is configured to receive an exhaust gas. The first dosing module is coupled to the first decomposition chamber and configured to provide a first treatment fluid into the first decomposition chamber. The first conversion catalyst member is configured to receive a mixture of the first treatment fluid and the exhaust gas, from the first decomposition chamber. The second decomposition chamber is configured to receive the exhaust gas from the first conversion catalyst member. The second dosing module is coupled to the second decomposition chamber and configured to provide a second treatment fluid into the second decomposition chamber.