Reductant injection and decomposition system

A reductant injection and decomposition system for a selective catalytic reduction system, comprising:

• a housing through which an exhaust gas stream is flowable, the housing including a reductant injector receptacle;
• and
• a perforated tubular element coupled to the reductant injector receptacle in exhaust gas receiving communication with the exhaust gas stream and in reductant spray receiving communication with a reductant injector coupled to the perforated tubular element, the perforated tubular element comprising an inlet, an outlet, and a diverging sidewall extending from the inlet to the outlet, wherein a plurality of perforations are formed in the diverging sidewall, the diverging sidewall also having a truncated conical shape with an upstream leading edge that is shorter than a downstream trailing edge,
• wherein reductant spray from the reductant injector flows within the perforated tubular element from the inlet to the outlet and a portion of the exhaust gas stream enters the perforated tubular element via a plurality of perforations proximate the upstream leading edge and exits the perforated tubular element via a plurality of perforations proximate the downstream trailing edge.

A method for injecting reductant into an exhaust gas stream, comprising:

• positioning a perforated tubular element in the exhaust gas stream and in reductant receiving communication with a reductant injector, the perforated tubular element comprising an inlet, an outlet, and a diverging sidewall extending from the inlet to the outlet, wherein a plurality of perforations are formed in the diverging sidewall, the diverging sidewall also having a truncated conical shape with an upstream leading edge that is shorter than a downstream trailing edge;
• injecting a reductant spray into the perforated tubular element via the inlet;
• pushing a portion of the exhaust gas stream into the tubular element through a plurality of perforations proximate the upstream leading edge;
• and
• pulling the portion of the exhaust gas stream within the tubular element out of the tubular element through a plurality of perforations proximate the downstream trailing edge.

A method for injecting reductant into an exhaust gas stream, comprising:

• positioning a perforated tubular element in a bulk exhaust gas stream and in reductant receiving communication with a reductant injector, the perforated tubular element comprising an inlet, an outlet, and a diverging sidewall extending from the inlet to the outlet, wherein a plurality of perforations are formed in the diverging sidewall, the diverging sidewall also having a truncated conical shape with an upstream leading edge that is shorter than a downstream trailing edge;
• injecting a reductant spray into the perforated tubular element via the inlet;
• diverting a portion of the bulk exhaust gas stream into the perforated tubular element through a plurality of perforations proximate the upstream leading edge, through the perforated tubular element, and out of the perforated tubular element through a plurality of perforations proximate the downstream trailing edge;
• and
• rejoining the portion of the exhaust gas stream with the bulk exhaust gas stream downstream of the perforated tubular element.