Dosing and mixing arrangement for use in exhaust aftertreatment

Patent metadata

Field	Value
Publication number	US-10245564-B2
Application number	US-201715650502-A
Country	US
Kind code	B2
Filing date	Jul 14, 2017
Priority date	Feb 15, 2013
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

A method for causing exhaust gas flow to flow at least 270 degrees in a first direction about a perforated tube using a baffle plate having a main body with a plurality of flow-through openings and a plurality of louvers positioned adjacent to the flow-through openings. The method includes deflecting a first portion of the exhaust gas flow with the main body of the baffle plate. The method also includes allowing a second portion of the exhaust gas flow to flow through the flow-through openings of the baffle plate. The method also deflects the second portion of the exhaust gas flow at a downstream side of the main body with the louvers hereby causing the second portion of the exhaust gas flow to flow in the first direction about the perforated tube.

First claim

What is claimed is:

1. 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.

2. The dosing and mixing arrangement of claim 1 , further comprising an exhaust treatment substrate positioned within the main housing body, the baffle plate being positioned between the perforated tube and the exhaust treatment substrate.

3. The dosing and mixing arrangement of claim 1 , wherein the open flow area is larger than a total area defined by the flow-through openings.

4. The dosing and mixing arrangement of claim 1 , wherein at least 10% of the perforated tube overlaps with the open flow area.

5. The dosing and mixing arrangement of claim 1 , wherein the free edge is, parallel to the tube axis.

6. The dosing and mixing arrangement of claim 1 , wherein the second end of the main housing body includes a curved portion that curves partially around the perforated tube.

7. The dosing and mixing arrangement of claim 1 , further comprising a reactant dispenser for dispensing a reactant within an interior of the perforated tube such that the reactant is mixed with the exhaust gas flow within the interior of the perforated tube.

8. The dosing and mixing arrangement of claim 1 , wherein the baffle plate is configured to cause the exhaust gas flow to flow circumferentially in one direction around at least 270 degrees of an exterior of the perforated tube.

9. The dosing and mixing arrangement of claim 1 , wherein the baffle plate is curved.

10. The dosing and mixing arrangement of claim 1 , wherein the perforated tithe is cylindrical.

11. The dosing and mixing arrangement of claim 1 , wherein the perforated tube has a first end being closed by the housing and a second end extending out of the housing.

12. The dosing and mixing arrangement of claim 11 , wherein the second end is an open end defining the outlet of the housing.

13. The dosing and mixing arrangement of claim 11 , further comprising an exhaust treatment substrate positioned within the main housing body, the exhaust treatment substrate defining a longitudinal axis, wherein the perforated tube defines a central axis extending from the first end to the second end that is generally perpendicular to the longitudinal axis.

14. The dosing and mixing arrangement of claim 1 , further comprising a perforated plate defining a plurality of apertures therethrough, the perforated plate being positioned within the housing between the inlet and the baffle plate.

15. The dosing and mixing arrangement of claim 1 , further comprising an injector for dispensing a reactant into the exhaust into the interior of the perforated tube.

16. The dosing and mixing arrangement of claim 15 , wherein the injector is positioned inside the perforated tube at the first end.

17. 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.

18. The dosing and mixing arrangement of claim 17 , wherein the closed end of the mixing tube is closed by the housing.

19. The dosing and mixing arrangement of claim 17 , further comprising a loser mounted to the closed end of the mixing tube.

Assignees

• Donaldson Co Inc

Inventors

• De Rudder Korneel
• Le Merdy Stéphane

Classifications

• F01N2470/18

  the axis of inlet or outlet tubes being other than the longitudinal axis of apparatus · CPC title

• F01N2470/04

  characterised by shape, disposition or dimensions of apertures · CPC title

• F01N2240/20

  a flow director or deflector · CPC title

• F01N3/2892

  Exhaust flow directors or the like, e.g. upstream of catalytic device · CPC title

• F01N3/0842

  Nitrogen oxides · CPC title