COMPACT MIXER WITH FLOW DIVERTER

• US 20200131969A1
• Filed: 09/01/2017
• Published: 04/30/2020
• Est. Priority Date: 09/01/2017
• Status: Active Grant

• Current Assignee: Faurecia Emissions Technologies, USA, LLC
• Original Assignee: Faurecia Emissions Control Technologies USA LLC (Forvia SE)
• Inventors: Tucker, Alfred N., Kozakeiwicz, Thomasz, Quadri, Syed Saleem, Prairie, Jeff
• Granted Patent: US 11,313,266 B2
• Time in Patent Office: Days
• CPC Class Codes: B01F 23/2132 using nozzles
• CPC Class Codes: B01F 25/3131 with additional mixing means other than injector mixers, e.g. screens, baffles or rotating elements
• CPC Class Codes: F01N 13/00 Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
• CPC Class Codes: F01N 2240/20 a flow director or deflector
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• CPC Class Codes: F01N 3/0807 by using absorbents or adsorbents
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 3/2892 Exhaust flow directors or the like, e.g. upstream of catalytic device

Abstract

A mixer assembly for a vehicle exhaust system includes an inner wall surface and a flow diverter with a flow directing surface that is spaced apart from the inner wall surface to provide an exhaust gas inlet area. The flow directing surface terminates at a distal end that is spaced apart from the inner wall surface to provide an orifice between the distal end and the inner wall surface through which exhaust gas flow accelerates and is directed to flow along the inner wall surface. A vehicle exhaust component assembly that includes the mixer and a method for mixing injected fluid spray into the mixer are also disclosed.

Claims

1. A mixer assembly for an exhaust system comprising:

an inner wall surface; and

a flow diverter including a flow directing surface spaced apart from the inner wall surface to provide an exhaust gas inlet area, and wherein the flow directing surface terminates at a distal end that is spaced apart from the inner wall surface to provide an orifice between the distal end and the inner wall surface through which exhaust gas flow accelerates and is directed to flow along the inner wall surface.

2. The mixer assembly according to claim 1, wherein the flow directing surface includes a first wall portion that extends outwardly from the inner wall surface and a second wall portion that extends transversely from the first wall portion to terminate at the distal end which is spaced apart from the inner wall surface by a gap to provide the orifice.

3. The mixer assembly according to claim 2, including an inlet baffle with at least one inlet opening that directs exhaust gas flow into the exhaust gas inlet area between the inner wall surface and the flow directing surface.

4. The mixer assembly according to claim 3, including a cone having a cone inlet that receives injected fluid spray to mix with exhaust gas flow exiting the orifice, and wherein the exhaust gas inlet area is free from injected spray.

5. The mixer assembly according to claim 1, including an outer housing defining an internal cavity that receives engine exhaust gases and an inner wall positioned within the internal cavity and spaced inward of the outer housing, and wherein the inner wall defines the inner wall surface that faces the flow directing surface.

6. The mixer assembly according to claim 5, wherein the outer housing comprises a curved housing surface that surrounds a mixer center axis, and wherein the inner wall is spaced radially inwardly of the curved housing surface and extends at least partially about the mixer center axis.

7. The mixer assembly according to claim 6, including an inlet baffle supported by an upstream end of the outer housing, an outlet baffle supported by a downstream end of the outer housing, and a cone having a cone inlet configured to receive injected fluid spray and a cone outlet that directs a mixture of exhaust gas and spray into the internal cavity, and wherein the inlet baffle includes at least one first opening that directs exhaust gas into the exhaust gas inlet area and a second opening that directs exhaust gas into the cone inlet.

8. The mixer assembly according to claim 7, wherein the first opening overlaps the inlet exhaust gas area and receives a first percentage of the exhaust gas flow, and wherein the second opening receives a second percentage of the exhaust gas flow that is less than the first percentage.

9. The mixer assembly according to claim 8, wherein the inlet baffle includes at least one elongated scoop with a scoop opening that directs exhaust gas flow into the internal cavity, and wherein the inlet baffle includes a plurality of secondary openings that are smaller than the first and second openings.

10. The mixer assembly according to claim 7, wherein exhaust gas flow exiting the orifice is free from injected spray and subsequently mixes with the mixture of exhaust gas and spray exiting the cone outlet.

11. A vehicle exhaust component assembly comprising:

a mixer housing defining an internal cavity and surrounding a mixer center axis, wherein the mixer housing has an inner wall surface;

an inlet baffle supported by an upstream end of the mixer housing, wherein the inlet baffle includes a plurality of inlet openings;

an outlet baffle supported by a downstream end of the mixer housing, wherein the outlet baffle includes at least one outlet opening;

an injection cone positioned between the inlet and outlet baffles, the injection cone having a cone inlet configured to receive injected fluid spray and a cone outlet to direct a mixture of injected fluid spray and exhaust gas into the internal cavity; and

a flow diverter including a flow directing surface spaced apart from the inner wall surface to provide an exhaust gas inlet area that receives exhaust gas from at least one of the inlet openings and which is free from injected fluid spray, and wherein the flow directing surface terminates at a distal end that is spaced apart from the inner wall surface to provide an orifice between the distal end and the inner wall surface that accelerates exhaust gas flow through the orifice and directs the exhaust gas flow to flow along the inner wall surface to mix with the mixture of injected fluid spray and exhaust gas exiting the cone outlet.

12. The vehicle exhaust component assembly according to claim 11, wherein the mixer housing comprises an outer wall that extends completely around the mixer center axis and an inner wall that is spaced radially inward of the outer wall and extends at least partially about the mixer center axis, and wherein the inner wall provides the inner wall surface that faces the mixer center axis.

13. The vehicle exhaust component assembly according to claim 11, wherein the plurality of inlet openings includes at least a first inlet opening that directs a first portion of exhaust gas into the exhaust gas inlet area, a second opening that directs a second portion of exhaust gas toward the cone inlet, and a plurality of third openings that direct a remaining portion of the exhaust gas into the internal cavity, and wherein the first portion is greater than the second portion.

14. The vehicle exhaust component assembly according to claim 13, wherein the plurality of third openings includes at least one scoop opening, and wherein any other third openings are smaller than the first and second openings.

15. The vehicle exhaust component assembly according to claim 13 wherein the first and second openings are located adjacent an outer peripheral edge of the inlet baffle and are circumferentially spaced apart from each other.

16. The vehicle exhaust component assembly according to claim 11, wherein the flow directing surface includes a first wall portion that extends outwardly from the inner wall surface and a second wall portion that extends transversely from the first wall portion to terminate at the distal end which is spaced apart from the inner wall surface by a gap to define the orifice.

17. The vehicle exhaust component assembly according to claim 16, wherein the first and second wall portions cooperate to turn exhaust gas flow entering the exhaust gas inlet area at least ninety degrees prior to exiting the orifice.

18. A method for mixing an injected fluid spray and exhaust in a mixer comprising the steps of:

providing a housing with an internal cavity having an inner wall surface;

positioning an injection cone in the internal cavity;

injecting fluid spray into a cone inlet of the injection cone to mix with exhaust gas prior to exiting a cone outlet;

spacing a flow diverter with a flow directing surface apart from the inner wall surface to provide an exhaust gas inlet area;

positioning the flow directing surface to terminate at a distal end that is spaced apart from the inner wall surface to provide an orifice between the distal end and the inner wall surface; and

accelerating exhaust gas flow through the orifice and directing the exhaust gas flow to flow along the inner wall surface to mix with injected fluid spray and exhaust gas exiting the cone outlet.

19. The method according to claim 18, wherein the exhaust gas inlet area is free from injected fluid spray.

20. The method according to claim 18, including using the flow diverter to turn exhaust gas flow entering the exhaust gas inlet area at least ninety degrees prior to exiting the orifice.