CN107489502B

CN107489502B - Tail gas aftertreatment mixing arrangement

Info

Publication number: CN107489502B
Application number: CN201610422729.7A
Authority: CN
Inventors: 王聪; 童毅君; 陈智; 毛伟
Original assignee: Tenneco Suzhou Emission System Co Ltd
Current assignee: Tenneco Suzhou Emission System Co Ltd
Priority date: 2016-06-13
Filing date: 2016-06-13
Publication date: 2020-06-30
Anticipated expiration: 2036-06-13
Also published as: CN108915830B; WO2017215460A1; CN107489502A; CN108915830A

Abstract

The utility model provides a tail gas aftertreatment mixing arrangement, its includes the casing, is located mixing assembly and baffle in the casing, wherein the baffle will the casing is divided into the first cavity with the import intercommunication and the second cavity with the export intercommunication. The mixing assembly comprises an inner pipe, a distribution body, an outer pipe and an end cover, the inner pipe is provided with a first pipe body located in the first cavity and a second pipe body extending into the second cavity, the wall surface of the first pipe body is provided with a plurality of spinning disks, and the wall surface of the second pipe body is provided with a plurality of first through holes for air flow to pass through; the distributing body is provided with a plurality of through holes for air flow to pass through; the outer pipe is positioned at the periphery of the second pipe body, and the wall surface of the outer pipe is provided with a plurality of second through holes for air flow to pass through; the end cap is positioned at the bottom of the outer tube and used for forcing the airflow to reversely flow. So set up, increased the distance and the time of urea evaporation, improved the homogeneity that the air current mixes.

Description

Tail gas aftertreatment mixing arrangement

Technical Field

The invention relates to a tail gas aftertreatment mixing device, and belongs to the technical field of engine tail gas aftertreatment.

Background

Studies have shown that the degree of uniformity of ammonia distribution in the lines of an exhaust aftertreatment system (e.g., a selective catalytic reduction system, SCR system) has a significant impact on the overall performance and durability of the system. Uneven distribution of ammonia can result in local areas with excessive ammonia and thus ammonia slip, while other ammonia lean areas can result in inefficient nitrogen-oxygen (NOx) conversion. The uneven distribution of ammonia over time can result in uneven catalyst aging, thereby affecting the overall performance of the catalyst. In addition, the uneven distribution of urea liquid drops can cause that the temperature of a local pipe wall or a mixed structure is too low, crystals are formed, and a tail gas pipe is blocked when the temperature is serious, so that the power performance of an engine is reduced.

Therefore, there is a need to provide a new exhaust gas post-treatment mixing device to solve the above technical problems.

Disclosure of Invention

The invention aims to provide a tail gas aftertreatment mixing device capable of uniformly mixing.

In order to achieve the purpose, the invention adopts the following technical scheme: a tail gas aftertreatment mixing device comprises a shell, a mixing assembly and a partition plate, wherein the mixing assembly is located in the shell, the partition plate is matched with the mixing assembly, the shell is provided with a mounting seat used for mounting a urea nozzle to spray urea into the mixing assembly, the partition plate divides the shell into a first cavity communicated with an inlet and a second cavity communicated with an outlet, the mixing assembly comprises an inner pipe, a distributing body matched with the inner pipe, an outer pipe located on the periphery of the inner pipe and an end cover matched with the outer pipe, the inner pipe is provided with a first pipe body located in the first cavity and a second pipe body extending into the second cavity, the wall surface of the first pipe body is provided with a plurality of swirl vanes, and the wall surface of the second pipe body is provided with a plurality of first through holes for air flow to pass through; the distributing body is provided with a plurality of through holes for air flow to pass through; the outer pipe is positioned at the periphery of the second pipe body, and the wall surface of the outer pipe is provided with a plurality of second through holes for air flow to pass through; the end cap is positioned at the bottom of the outer tube and used for forcing the airflow to reversely flow.

As a further improved technical solution of the present invention, the partition board includes a first plate located on one side of the mixing component, a second plate located on the other side of the mixing component, and a third plate connecting the first plate and the second plate, and the third plate is provided with a mounting hole for the mixing component to pass through.

As a further improved technical scheme of the invention, the clapboard is approximately Z-shaped, the first plate and the second plate both extend vertically and have opposite extending directions, and the third plate extends horizontally.

As a further improved technical solution of the present invention, the third plate is provided with a slot located at the periphery of the mounting hole, and the slot communicates the first cavity and the second cavity.

As a further improved technical scheme of the invention, the first pipe body comprises a plurality of openings positioned at the upper part of the spinning disk, and the openings are close to the mounting seat and communicated with the first cavity.

As a further improved technical scheme of the invention, the outer pipe is attached to the second plate.

As a further improved technical scheme of the invention, the second plate is provided with a slot, and the outer pipe at least partially protrudes out of the slot to be directly exposed in the first cavity.

As a further improved technical solution of the present invention, the distribution body is fixed at the bottom of the first tube.

As a further improved technical scheme of the invention, the ligand is in a circular arc shape.

As a further improved technical scheme of the invention, the end cover is provided with a bulge which protrudes into the second tube body and is used for forcing the airflow to reversely flow.

As a further improvement of the present invention, the dispenser is located above the end cap and is vertically spaced from the end cap.

Compared with the prior art, the mixing uniformity of the tail gas and the urea liquid drops is improved by arranging the spinning disk; by arranging the ligand, urea liquid drops are crushed to be smaller, and the atomization and mixing effects of urea are improved; in addition, the inner pipe and the outer pipe are arranged, and the air flow is forced to flow in the opposite direction through the end cover, so that the evaporation distance and time of urea are increased, and the uniformity of air flow mixing is improved.

Drawings

Fig. 1 is a schematic perspective view of an exhaust gas aftertreatment mixing device according to the present invention.

Fig. 2 is an exploded perspective view of fig. 1.

Fig. 3 is a left side view of fig. 1.

Fig. 4 is a schematic cross-sectional view taken along line a-a of fig. 3.

Fig. 5 is a schematic cross-sectional view taken along line B-B in fig. 3.

Fig. 6 is a rear view of fig. 1.

Fig. 7 is a schematic sectional view taken along line C-C in fig. 6.

Fig. 8 is an exploded perspective view of an exhaust aftertreatment mixing arrangement according to another embodiment of the invention.

FIG. 9 is a schematic cross-sectional view of the exhaust aftertreatment mixing device of FIG. 8 taken at an angle.

Detailed Description

Referring to fig. 1 to 7, an exhaust gas aftertreatment hybrid device 100 is disclosed for use in an aftertreatment system, such as SCR, to treat exhaust gas from an engine. The exhaust gas aftertreatment mixing device 100 comprises a shell 1, a mixing component 2 installed in the shell 1 and a partition plate 3 matched with the mixing component 2.

In the illustrated embodiment of the present invention, the housing 1 has a cylindrical shape, and is provided with a mounting plate 11 recessed into the housing 1 and a mounting seat 12 welded to the mounting plate 11. The mounting seat 12 is used for mounting a urea nozzle (not shown) to inject urea into the mixing assembly 2.

The partition 3 divides the housing 1 into a first chamber 13 communicating with the inlet and a second chamber 14 communicating with the outlet. In the illustrated embodiment of the invention, the separator 3 is substantially Z-shaped and comprises a first plate 31 located on one side of the mixing element 2, a second plate 32 located on the other side of the mixing element 2 and a third plate 33 connecting the first plate 31 and the second plate 32. The first plate 31 and the second plate 32 both extend vertically and extend in opposite directions. The third plate 33 extends horizontally. The third plate 33 is provided with a mounting hole 331 for the mixing component 2 to pass through and a slot 332 at the periphery of the mounting hole 331.

The mixing assembly 2 comprises an inner tube 21, a distributing body 22 cooperating with the inner tube 21, an outer tube 23 located at the periphery of the inner tube 21, and an end cap 24 cooperating with the outer tube 23. Wherein the inner tube 21 is provided with a first tube 211 located in the first cavity 13 and a second tube 212 extending into the second cavity 14. The wall surface of the first tube 211 is provided with a plurality of swirl vanes 2111 and a plurality of openings 2112 located at the upper portions of the swirl vanes 2111. The swirl plate 2111 is located in the first chamber 13. The opening 2112 is adjacent to the mounting seat 12 and communicates with the first cavity 13. The slot 332 connects the first cavity 13 and the second cavity 14, and the slot 332 can blow the air flow passing through to the inner wall of the outer tube 23 to blow away the crystal, thereby reducing the crystallization risk. In the illustrated embodiment of the present invention, the wall surface of the first pipe 211 is in the shape of a circular truncated cone. The wall surface of the second tube 212 is provided with a plurality of first through holes 2121 through which air flows. The distributing body 22 is provided with a plurality of through holes 221 through which the air flow passes. The outer tube 23 is located at the periphery of the second tube 212, and the wall surface of the outer tube 23 is provided with a plurality of second through holes 231 for the air flow to pass through. The end cap 24 is located at the bottom of the outer tube 23 to force the airflow to flow in the opposite direction.

In the illustrated embodiment of the present invention, the dispenser 22 is fixed to the bottom of the first tube 211. The ligand 22 has a circular arc shape. The end cap 24 is provided with a protrusion 241 protruding into the second tube 212 for forcing the airflow to flow reversely. The dispensing body 22 is located above the end cap 24 and is vertically spaced from the end cap 24.

Referring to fig. 5, after assembly, the wall surface of the outer tube 23 is attached to the second plate 32. So configured, on the one hand, the size required for the arrangement can be reduced; on the other hand, the second plate 32 and the outer tube 23 may be heated by the exhaust gas, thereby further reducing the risk of urea crystals forming in the outer tube 23.

When the exhaust gas of the engine enters the first cavity 13 from the inlet, most of the exhaust gas is guided by the swirl plate 2111 to rotate into the inner tube 21, and a small amount of exhaust gas enters the inner tube 21 from the opening 2112. When the injection condition is satisfied, the urea nozzle injects urea into the mixing assembly 2, and the atomized urea droplets are mixed together with the exhaust gas of the engine and rotate downward. The through holes 221 of the distributing body 22 can make the urea hitting the through holes broken into smaller liquid drops, thereby improving the atomization and mixing effect of the urea. The airflow is then forced in a reverse (e.g., upward) direction by the end cap 24. The reversed air flow passes through the first perforation 2121 and/or the second perforation 231 and exits from the outlet. So set up, increased the distance and the time of urea evaporation, improved the homogeneity that the air current mixes, reduced the risk of urea crystallization.

Referring to fig. 8 and 9, in another embodiment of the exhaust gas aftertreatment hybrid device 100 of the present invention, the second plate 32 has a slot 321. When the outer tube 23 is assembled with the second plate 32, the outer tube 23 at least partially protrudes out of the slot 321. With this arrangement, the wall of the outer tube 23 directly exposed to the first cavity 13 can be heated by the exhaust gas, thereby further reducing the risk of urea crystals forming in the outer tube 23.

In addition, the above embodiments are only used for illustrating the invention and not for limiting the technical solutions described in the invention, and the understanding of the present specification should be based on the technical personnel in the field, and although the present specification has described the invention in detail by referring to the above embodiments, the ordinary skilled in the art should understand that the technical personnel in the field can still make modifications or equivalent substitutions to the present invention, and all the technical solutions and modifications thereof without departing from the spirit and scope of the present invention should be covered in the claims of the present invention.

Claims

1. The utility model provides a tail gas aftertreatment mixing arrangement, its includes the casing, is located mixing assembly in the casing and with mixing assembly matched with baffle, wherein the casing is equipped with and is used for installing the urea nozzle with to the mount pad of spraying urea in the mixing assembly, the baffle will the casing is separated into the first cavity with the import intercommunication and the second cavity with the export intercommunication, its characterized in that: the mixing assembly comprises an inner pipe, a distributing body matched with the inner pipe, an outer pipe positioned on the periphery of the inner pipe and an end cover matched with the outer pipe, the inner pipe is provided with a first pipe body positioned in the first cavity and a second pipe body extending into the second cavity, the wall surface of the first pipe body is provided with a plurality of spinning disks, and the wall surface of the second pipe body is provided with a plurality of first through holes for air flow to pass through; the distributing body is provided with a plurality of through holes for air flow to pass through; the outer pipe is positioned at the periphery of the second pipe body, and a plurality of second through holes for air flow to pass through are formed in the wall surface of the outer pipe; the end cap is positioned at the bottom of the outer tube and used for forcing the airflow to reversely flow.

2. The exhaust aftertreatment mixing arrangement of claim 1, wherein: the clapboard comprises a first plate sheet positioned on one side of the mixing component, a second plate sheet positioned on the other side of the mixing component and a third plate sheet connecting the first plate sheet and the second plate sheet, and the third plate sheet is provided with a mounting hole for the mixing component to pass through.

3. The exhaust aftertreatment mixing arrangement of claim 2, wherein: the partition board is approximately Z-shaped, the first plate and the second plate extend vertically and extend in opposite directions, and the third plate extends horizontally.

4. The exhaust aftertreatment mixing arrangement of claim 2, wherein: the third plate is provided with a slot positioned on the periphery of the mounting hole, and the slot is communicated with the first cavity and the second cavity.

5. The exhaust aftertreatment mixing arrangement of claim 1, wherein: the first pipe body comprises a plurality of openings located on the upper portion of the spinning disk, and the openings are close to the mounting seat and communicated with the first cavity.

6. The exhaust aftertreatment mixing arrangement of claim 2, wherein: the outer tube is attached to the second plate.

7. The exhaust aftertreatment mixing arrangement of claim 6, wherein: the second plate is provided with a slot, and the outer pipe at least partially protrudes out of the slot so as to be directly exposed in the first cavity.

8. The exhaust aftertreatment mixing arrangement of claim 1, wherein: the distribution body is fixed at the bottom of the first pipe body.

9. The exhaust aftertreatment mixing arrangement of claim 1, wherein: the sub-ligand is arc-shaped.

10. The exhaust aftertreatment mixing arrangement of claim 1, wherein: the dispenser is located above and vertically spaced from the end cap.