Dosing and mixing arrangement for use in exhaust aftertreatment

A dosing and mixing arrangement comprising:

• a housing including a main housing body that defines a central housing axis, the main housing body having a length that extends along the central housing axis between first and second opposite ends of the main housing body, the housing also including an inlet adjacent the first end of the main housing body and an outlet adjacent the second end of the main housing body;
• a perforated tube forming the outlet of the housing, the perforated tube defining a tube axis aligned at an angle relative to the central housing axis;
• the main housing body defining an interior volume that extends between the exhaust treatment substrate and the perforated tube, the interior volume defining a transverse cross-sectional area that is transverse relative to the central housing axis;
• a baffle plate positioned within the interior volume between the perforated tube and the inlet, the baffle plate having a main plate body having an upstream side that faces toward the inlet and a downstream side that faces toward the perforated tube, the main plate body defining a plurality of flow-through openings that extend through the main plate body between the upstream and downstream sides of the main plate body, the baffle plate also including a plurality of louvers positioned adjacent to the flow-through openings at the downstream side of the main plate body, the main plate body having a connected edge that is connected to an interior of the main housing body and a free edge that extends across the interior volume of the main housing body, the main plate body being sized and shaped to coincide with only a portion of the transverse cross-sectional area of the interior volume such that an open flow area is defined between the free edge and the interior of the main housing body;
• and
• wherein a first portion of exhaust gas flow through the housing is directed though the open flow area and then in a first rotational direction around the perforated tube, and wherein a second portion of the exhaust gas flow passes through the flow-through openings and is deflected in the first rotation direction about the perforated tube by the louvers.

A dosing and mixing arrangement comprising:

• a mixing tube having an interior, an exterior, and at least a first portion defining a first plurality of apertures;
• a swirl structure including at least one plate defining a plurality of baffles and a second plurality of apertures in between the baffles, the plate causing exhaust flow to move both around the plate and also through the second plurality of apertures and to swirl outside the exterior of the first portion of the mixing tube in one rotational direction along a flow path that extends at least 270 degrees around a central axis of mixing tube and into the interior of the mixing tube through the first plurality of apertures;
• and
• a doser for dispensing a reactant into the exhaust.

An exhaust arrangement for dosing and mixing a reactant into exhaust comprising:

• a housing defining an inlet of the exhaust arrangement;
• a substrate being positioned within the housing and defining a longitudinal axis;
• a cylindrical mixing tube having an exterior, an interior, at least a portion of the cylindrical mixing tube defining a first plurality of apertures through the exterior of the cylindrical mixing tube, a first end being closed by the housing, and a second end that is an open end defining an outlet of the exhaust arrangement, the cylindrical mixing tube defining a central axis extending from the first end to the second end that is generally perpendicular to the longitudinal axis;
• a curved baffle plate defining a plurality of baffles and a second plurality of apertures in between the baffles, the curved baffle plate being positioned within the housing between at least a portion of the substrate and at least a portion of the cylindrical mixing tube, the curved baffle plate being coupled at a first end to an interior of the housing and including a second free end, the curved baffle plate at least partially surrounding the exterior of the cylindrical mixing tube, wherein each baffle of the plurality of baffles projects away from the curved main body and towards the cylindrical mixing tube such that exhaust flow is directed to swirl outside of the first portion of the cylindrical mixing tube and into the interior of the cylindrical mixing tube through the first plurality of apertures as the exhaust swirls in one rotational direction along a flow path that extends at least 270 degrees around a central axis of the cylindrical mixing tube;
• the exhaust arrangement defining a flow-through region between the substrate and the cylindrical mixing tube that is unobstructed by the curved baffle plate and a deflection region disposed generally between the substrate and the baffle such that the plurality of baffles of the curved baffle plate are configured to deflect the exhaust flow both in a rotational direction around the exterior of the cylindrical mixing tube along a flow path that extends at least 270 degrees around the central axis and also through the first plurality of apertures of the cylindrical mixing tube;
• a perforated plate having a third plurality of apertures, the perforated plate being positioned within the housing and positioned between the inlet and the substrate;
• and
• a doser for dispensing a reactant into the exhaust into the interior of the cylindrical mixing tube, the doser being positioned inside the cylindrical mixing tube at the first end.