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 inlet 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 a downstream side that faces toward the perforated tube and an upstream side, 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 of the main plate 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 housing defining an interior;
• a mixing tube disposed within the interior of the housing, the mixing tube having an interior, an exterior, and at least a first portion defining a first plurality of apertures, the first portion surrounding a tube axis of the mixing tube, the tube axis extending between a closed end of the mixing tube and an open end of the mixing tube;
• and
• a swirl structure including at least one plate curving partially around the tube axis of the mixing tube, the plate defining a plurality of baffles and a second plurality of apertures positioned adjacent to 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 the mixing tube and into the interior of the mixing tube through the first plurality of apertures.