Diesel exhaust fluid mixing

Patent metadata

Field	Value
Publication number	US-10954841-B2
Application number	US-201715725458-A
Country	US
Kind code	B2
Filing date	Oct 5, 2017
Priority date	Oct 5, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A canister assembly for use in an exhaust gas aftertreatment device comprises a cylindrical shell defining a cylindrical axis, a radial direction, and a circumferential direction, a top end and a bottom end. A flow tube is inserted into the top end of the cylindrical shell and terminates short of the bottom end of the cylindrical shell, defining an exit of the flow tube. A mixing bowl member including a symmetrical annular shape about the cylindrical axis and defining a mixing bowl pocket is attached at the bottom end of the cylindrical shell.

First claim

What is claimed is:

1. A canister assembly for use in an exhaust gas aftertreatment device, the canister assembly comprising:
a cylindrical shell defining a cylindrical axis, a radial direction, and a circumferential direction, a top end, a bottom end and an interior between the top end and the bottom end;
a flow tube inserted into the top end of the cylindrical shell and terminating short of the bottom end of the cylindrical shell, defining an exit of the flow tube; and
a mixing bowl member including a generally symmetrical annular shape about the cylindrical axis and defining a mixing bowl pocket being in fluid communication with the interior of the cylindrical shell, the mixing bowl member being fixedly attached at the bottom end of the cylindrical shell and the exit of the flow tube is positioned radially above the mixing bowl pocket and spaced axially away from the mixing bowl member;
wherein an exhaust gas treatment liquid injection point is disposed proximate the top end of the cylindrical shell and includes an outlet to inject exhaust gas treatment liquid into the flow tube to define a first mixing phase of exhaust gas and the exhaust gas treatment liquid, and the mixing bowl defines a second mixing phase of exhaust gas and the exhaust gas treatment liquid, the second mixing phase being disposed downstream of the first mixing phase.

2. The canister assembly of claim 1 , wherein the flow tube defines an inlet that is disposed axially outside the top end of the cylindrical shell.

3. The canister assembly of claim 2 , further comprising a charge air injection point that is disposed axially outside the top end of the cylindrical shell radially opposite of the exhaust gas treatment liquid injection point.

4. The canister assembly of claim 1 , wherein the cylindrical shell defines a circumferential surface and an outlet point along the circumferential surface of the cylindrical shell.

5. The canister assembly of claim 4 , further comprising at least one annular shaped aftertreatment device disposed in the cylindrical shell about the flow tube.

6. The canister assembly of claim 5 , wherein the at least one annular shaped aftertreatment device includes one of the following: diesel oxidation catalyst, diesel particulate filter, selective catalytic reduction, and ammonia oxidation catalyst.

7. The canister assembly of claim 1 , wherein the cylindrical shell defines an axial length ranging from 9 inches to 27 inches and a diameter ranging from 3 inches to 9 inches.

8. A canister subassembly for use in an exhaust gas aftertreatment device, the canister subassembly comprising:
a cylindrical shell defining a cylindrical axis, a radial direction, and a circumferential direction, a top end, a bottom end and an interior between the top end and the bottom end; and
a mixing bowl member including a generally symmetrical annular shape about the cylindrical axis and defining a mixing bowl pocket and including a flow divider facing towards the interior of the cylindrical shell, the mixing bowl member being fixedly attached at the bottom end of the cylindrical shell and the flow divider is radially centered;
wherein the flow divider is a projection that includes a peak and a conical surface that slopes away from the peak and the mixing bowl pocket defines an axial bottom extremity, and the conical surface terminates proximate the axial bottom extremity of the mixing bowl pocket, and the mixing bowl member includes a generally cylindrical shape that is inserted into the bottom end of the cylindrical shell.

9. The canister subassembly of claim 8 , the mixing bowl member is welded onto the cylindrical shell.

10. The canister subassembly of claim 8 , wherein the cylindrical shell defines a first axial length and the mixing bowl member defines a second axial length, and a ratio of the first axial length to the second axial length ranges from 8:1 to 20:1.

11. The canister subassembly of claim 8 , wherein the mixing bowl member further defines a bottom arcuate surface defining the bottom axial extremity of the mixing bowl pocket.

12. The canister subassembly of claim 11 , wherein the mixing bowl member further defines an inside cylindrical surface leading from the bottom arcuate surface toward the top axial surface, a top arcuate blend transitioning from the inside cylindrical surface to the top axial surface, and a lead-in surface connecting the top axial surface to the outer cylindrical surface.

13. The canister subassembly of claim 8 , wherein the outer cylindrical surface defines a diameter and the mixing bowl member defines an axial length measured from the top axial surface to the bottom axial surface, and a ratio of the axial length to the diameter ranges from 3:1 to 8:1.

14. The canister subassembly of claim 8 , wherein the mixing bowl member comprises a stainless steel.

15. A canister assembly for use in an exhaust gas aftertreatment device, the canister assembly comprising:
a cylindrical shell defining a cylindrical axis, a radial direction, and a circumferential direction, a top end, a bottom end and an interior between the top end and the bottom end;
a flow tube inserted into the top end of the cylindrical shell and terminating short of the bottom end of the cylindrical shell, defining an exit of the flow tube; and
a mixing bowl member including an annular shape about the cylindrical axis and defining a mixing bowl pocket being in fluid communication with the interior of the cylindrical shell, the mixing bowl member being fixedly attached at the bottom end of the cylindrical shell and the exit of the flow tube is positioned radially above the mixing bowl pocket and spaced axially away from the mixing bowl member;
wherein an exhaust gas treatment liquid injection point is disposed proximate the top end of the cylindrical shell and includes an outlet to inject exhaust gas treatment liquid into the flow tube to define a first mixing phase of exhaust gas and the exhaust gas treatment liquid, and the mixing bowl defines a second mixing phase of exhaust gas and the exhaust gas treatment liquid, the second mixing phase being disposed downstream of the first mixing phase.

16. The canister assembly of claim 15 , wherein the flow tube defines an inlet that is disposed axially outside the top end of the cylindrical shell.

17. The canister assembly of claim 16 , further comprising a charge air injection point that is disposed axially outside the top end of the cylindrical shell radially opposite of the exhaust gas treatment liquid injection point.

18. The canister assembly of claim 15 , wherein the cylindrical shell defines a circumferential surface and an outlet point along the circumferential surface of the cylindrical shell.

19. The canister assembly of claim 18 , further comprising at least one annular shaped aftertreatment device disposed in the cylindrical shell about the flow tube.

20. The canister assembly of claim 19 , wherein the at least one annular shaped aftertreatment device includes one of the following: diesel oxidation catalyst, diesel particulate filter, selective catalytic reduction, and ammonia oxidation catalyst and the cylindrical shell defines an axial length ranging from 9 inches to 27 inches and a diameter ranging from 3 inches to 9 inches.

Assignees

• Caterpillar Inc

Inventors

• Brinkmeyer Scott David

Classifications

• B01F25/435

  Mixing tubes composed of concentric tubular members · CPC title

• B01F23/2132

  using nozzles · CPC title

• B01F2025/916

  Turbulent flow, i.e. every point of the flow moves in a random direction and intermixes · CPC title

• B01F23/213

  by spraying or atomising of the liquids · CPC title

• B01F23/21

  by introducing liquids into gaseous media · CPC title