CN216110937U

CN216110937U - Mixing chamber subassembly and tail gas aftertreatment device

Info

Publication number: CN216110937U
Application number: CN202122872392.9U
Authority: CN
Inventors: 叶威; 吴涛涛; 严才宝; 刘翠洁
Original assignee: Tenneco Suzhou Emission System Co Ltd
Current assignee: Tenneco Suzhou Emission System Co Ltd
Priority date: 2021-11-22
Filing date: 2021-11-22
Publication date: 2022-03-22
Anticipated expiration: 2031-11-22

Abstract

A mixing cavity assembly comprises a mixing cavity shell and a mixing assembly arranged in the mixing cavity shell, wherein the mixing cavity shell is provided with a first opening communicated with a first post-processing carrier assembly, a second opening communicated with a second post-processing carrier assembly, a first cavity communicated with the first opening and a second cavity communicated with the second opening; the mixing assembly includes a first mixing assembly located in the first cavity, the first mixing assembly including a plurality of rods to break up urea droplets, each rod including an arcuate upper surface. The utility model also discloses an exhaust gas aftertreatment device with the mixing cavity assembly.

Description

Mixing chamber subassembly and tail gas aftertreatment device

Technical Field

The utility model relates to a mixing cavity assembly and a tail gas aftertreatment 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. 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.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a mixing cavity assembly with good urea crystallization resistance and an exhaust gas aftertreatment device.

In order to achieve the purpose, the utility model adopts the following technical scheme: a mixing cavity assembly comprises a mixing cavity shell and a mixing assembly arranged in the mixing cavity shell, wherein the mixing cavity shell is provided with a first opening communicated with a first post-processing carrier assembly, a second opening communicated with a second post-processing carrier assembly, a first cavity communicated with the first opening and a second cavity communicated with the second opening; the mixing assembly includes a first mixing assembly located in the first cavity, the first mixing assembly including a plurality of rods to break up urea droplets, each rod including an arcuate upper surface.

As a further improved technical scheme of the utility model, each rod is cylindrical and extends horizontally, and the rods are arranged at intervals.

As a further improved technical scheme of the utility model, the plurality of rods comprise a plurality of layers along the vertical direction, and the rods of two adjacent layers are arranged along the vertical direction in a staggered manner.

As a further improved technical solution of the present invention, the first mixing assembly includes a first side wall and a second side wall opposite to the first side wall, two ends of the rod are respectively fixed to the first side wall and the second side wall, and the first side wall and the second side wall are respectively provided with a plurality of slots for allowing the airflow to flow through.

As a further improved technical solution of the present invention, the first mixing component includes a rear wall connecting the first side wall and the second side wall, and the rear wall is provided with a plurality of slots for allowing the airflow to flow through.

As a further improved technical solution of the present invention, the first mixing component further includes an inclined wall extending obliquely upward from the rear wall, and the inclined wall is provided with a plurality of openings for allowing the airflow to flow through.

As a further improved technical solution of the present invention, the first mixing assembly further includes a front wall connecting the first side wall and the second side wall, and the front wall, the first side wall, the second side wall, and the rear wall form a frame.

As a further improved technical solution of the present invention, the mixing assembly includes a second mixing assembly located in the second cavity, and the second mixing assembly includes an ω -type swirl plate located at the bottom of the second mixing assembly and a baffle located above the ω -type swirl plate.

As a further improved technical solution of the present invention, the air deflector includes a first inclined plate and a second inclined plate, and the first inclined plate and the second inclined plate are arranged in a splayed shape; or the guide plate is C-shaped.

The utility model also discloses an exhaust gas aftertreatment device, which comprises a first aftertreatment carrier component, a second aftertreatment carrier component, a third aftertreatment carrier component positioned at the upstream of the first aftertreatment carrier component, and a mixing cavity component for connecting the first aftertreatment carrier component and the second aftertreatment carrier component, wherein the first aftertreatment carrier component is a diesel particle trap, the second aftertreatment carrier component is a selective catalytic reducing agent, the third aftertreatment carrier component is a diesel oxidation catalyst, and the mixing cavity component is the mixing cavity component.

Compared with the prior art, the urea liquid drop crushing device has the advantages that the rods with the arc-shaped upper surfaces are arranged, urea liquid drops can be crushed better by the rods, evaporation and decomposition of the urea liquid drops are facilitated, and the urea crystallization resistance of the mixing cavity assembly and the tail gas aftertreatment device is improved.

Drawings

FIG. 1 is a schematic view of an exhaust gas aftertreatment device according to the utility model.

Fig. 2 is a schematic perspective view of a mixing chamber assembly of the present invention in a first embodiment.

Fig. 3 is a perspective view of fig. 2 from another angle.

Fig. 4 is a partially exploded perspective view of fig. 3.

Fig. 5 is a perspective view of the first mixing assembly of fig. 4.

Fig. 6 is a perspective view of the second mixing assembly of fig. 4.

Fig. 7 is a front view of fig. 2.

Fig. 8 is a schematic sectional view taken along line a-a in fig. 7.

Fig. 9 is a schematic perspective view of a mixing chamber assembly of the present invention in a second embodiment.

Fig. 10 is a perspective view of fig. 9 from another angle.

Fig. 11 is a partially exploded perspective view of fig. 10.

Fig. 12 is a perspective view of the first mixing assembly of fig. 11.

Fig. 13 is a front view of fig. 9.

Fig. 14 is a schematic sectional view taken along line B-B in fig. 13.

Detailed Description

The following detailed description of the embodiments of the utility model will be described in conjunction with the accompanying drawings, in which, if there are several embodiments, the features of these embodiments can be combined with each other without conflict. When the description refers to the accompanying drawings, like numbers or symbols in different drawings represent the same or similar elements unless otherwise specified. The statements made in the following exemplary embodiments do not represent all embodiments of the present invention, but rather they are merely examples of products consistent with the present invention as recited in the claims of the present invention.

The terminology used in the description of the utility model herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention. It should be understood that the use of terms such as "first," "second," and the like, in the description and in the claims of the present invention do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another.

Referring to fig. 1, the present invention discloses an exhaust gas aftertreatment device, which includes a first aftertreatment carrier assembly 1, a second aftertreatment carrier assembly 2, a third aftertreatment carrier assembly 3 located at an upstream of the first aftertreatment carrier assembly 1, and a mixing chamber assembly 4 connecting the first aftertreatment carrier assembly 1 and the second aftertreatment carrier assembly 2. In one embodiment of the utility model, the first aftertreatment carrier component 1 is a diesel particulate trap (DPF), the second aftertreatment carrier component 2 is a Selective Catalytic Reduction (SCR) and the third aftertreatment carrier component 3 is a Diesel Oxidation Catalyst (DOC).

The mixing chamber assembly 4 comprises a mixing chamber housing 5 and a mixing assembly 6 mounted within the mixing chamber housing 5. The mixing chamber shell 5 is provided with a first opening 51 communicated with the first aftertreatment carrier assembly 1, a second opening 52 communicated with the second aftertreatment carrier assembly 2, a first cavity 53 communicated with the first opening 51, a second cavity 54 communicated with the second opening 52, a first fairing 55 close to the first opening 51 and a second fairing 56 close to the second opening 52. The mixing chamber housing 5 is provided with a mounting base 531 for mounting a urea nozzle 7, the urea nozzle 7 being configured to spray atomized urea droplets into the mixing assembly 6.

The first flow rectification plate 55 includes two airflow inlets 551 respectively located at two sides and a plurality of first airflow perforations 552 penetrating the first flow rectification plate 55. The air inlet 551 is advantageous for improving uniformity of air flowing into the first cavity 53. By providing the number of first airflow apertures 552, the back pressure of the airflow is facilitated to be regulated.

The second flow rectification plate 56 comprises two airflow outlets 561 respectively positioned at two sides and a plurality of second airflow through holes 562 penetrating through the second flow rectification plate 56. By providing the airflow outlet 561, uniformity is facilitated as the airflow exits the second chamber 54. By providing the number of second airflow apertures 562, it is advantageous to adjust the back pressure of the airflow.

The mixing assembly 6 includes a first mixing assembly 61 located in the first cavity 53 downstream of the first fairing 55 and a second mixing assembly 62 located in the second cavity 54 upstream of the second fairing 55. The first mixing assembly 61 comprises a number of rods 610 for breaking up urea droplets, each rod 610 comprising an arc-shaped upper surface 6101. Each rod 610 is cylindrical and extends horizontally, and the rods 610 are arranged at intervals. The rods 610 comprise a plurality of layers in the vertical direction, and the rods 610 in two adjacent layers are arranged in a staggered manner in the vertical direction; with this arrangement, the arrangement density of the rods 610 in the vertical direction in the projection plane of the first mixing unit 61 can be increased, and urea droplets sprayed from the urea nozzles 7 are prevented from directly flowing downward from the gaps between the rods 610 in a large amount. When the urea droplets sprayed from the urea nozzle 7 collide with the rod 610 at a certain speed, the urea droplets are easily broken down into smaller droplets, thereby facilitating evaporation and decomposition thereof and reducing the risk of urea crystallization.

Referring to fig. 2 to 8, in the first embodiment of the present invention, the first mixing member 61 includes a first sidewall 611, a second sidewall 612 opposite to the first sidewall 611, and a rear wall 613 connecting the first sidewall 611 and the second sidewall 612. The two ends of the rod 610 are respectively fixed to the first sidewall 611 and the second sidewall 612, and the first sidewall 611 and the second sidewall 612 are respectively provided with a plurality of

slots

6111, 6121 for the airflow to flow through. The rear wall 613 is provided with slots 6131 through which the air flows. In the first embodiment of the present invention, the front and rear ends of the first side wall 611 and the second side wall 612 are welded and fixed to the first flow rectification plate 55 and the mixing chamber housing 5, respectively.

Referring to fig. 9 to 14, the first mixing component 61 further includes a front wall 614 connecting the first side wall 611 and the second side wall 612, and the front wall 614, the first side wall 611, the second side wall 612 and the rear wall 613 form a frame. The first mixing member 61 further includes an inclined wall 615 extending obliquely upward from the rear wall 613. The inclined wall 615 can provide a certain breaking action to the urea droplets sprayed from the urea nozzle 7; in addition, the inclined wall 615 can also provide a certain direction for the airflow, thereby facilitating the flow and distribution of the airflow. The inclined wall 615 is provided with a number of openings 6151 through which the gas flow passes.

The second mixing assembly 62 includes an omega-shaped swirl plate 621 located at the bottom of the second mixing assembly 62 and a baffle 622 located above the omega-shaped swirl plate 621. The omega-shaped swirl plate 621 can form double swirl to the airflow in the second cavity 54, so that the mixing uniformity of the tail gas and the urea is improved, and the crystallization risk of the urea is reduced; at the same time, it is also advantageous to distribute the mixed gas flow uniformly over the inlet end face of the second aftertreatment carrier element 2. The omega-shaped swirl plate 621 and the two ends of the guide plate 622 are respectively welded and fixed on the second flow-rectifying plate 56 and the mixing cavity shell 5.

As shown in fig. 6, in the first embodiment of the present invention, the air deflector 622 includes a first inclined plate 6221 and a second inclined plate 6222, and the first inclined plate 6221 and the second inclined plate 6222 are arranged in a zigzag shape. The first inclined plate 6221 and the second inclined plate 6222 are each provided with an air flow through hole 6223 for passing an air flow therethrough.

Referring to fig. 11, in a second embodiment of the present invention, the diversion plate 622 is C-shaped. Through the C type guide plate 622 with omega type whirl board 621's cooperation is favorable to realizing better two whirl effects.

The above embodiments are only for illustrating the utility model and not for limiting the technical solutions described in the utility model, 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 utility model in detail with reference to the above embodiments, the technical personnel in the field 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. A mixing cavity assembly comprises a mixing cavity shell and a mixing assembly arranged in the mixing cavity shell, wherein the mixing cavity shell is provided with a first opening communicated with a first post-processing carrier assembly, a second opening communicated with a second post-processing carrier assembly, a first cavity communicated with the first opening and a second cavity communicated with the second opening; the method is characterized in that: the mixing assembly includes a first mixing assembly located in the first cavity, the first mixing assembly including a plurality of rods to break up urea droplets, each rod including an arcuate upper surface.

2. The mixing chamber assembly of claim 1, wherein: each rod is cylindrical and extends horizontally, and the rods are arranged at intervals.

3. The mixing chamber assembly of claim 2, wherein: the plurality of rods comprise a plurality of layers in the vertical direction, and the rods in two adjacent layers are arranged in a staggered mode in the vertical direction.

4. The mixing chamber assembly of claim 1, wherein: the first mixing assembly comprises a first side wall and a second side wall opposite to the first side wall, two ends of the rod are respectively fixed to the first side wall and the second side wall, and the first side wall and the second side wall are respectively provided with a plurality of slots through which airflow flows.

5. The mixing chamber assembly of claim 4, wherein: the first mixing assembly comprises a rear wall connecting the first side wall and the second side wall, and the rear wall is provided with a plurality of slots for airflow to flow through.

6. The mixing chamber assembly of claim 5, wherein: the first mixing assembly further comprises an inclined wall extending obliquely upwards from the rear wall, and the inclined wall is provided with a plurality of openings for the airflow to flow through.

7. The mixing chamber assembly of claim 5, wherein: the first mixing assembly further comprises a front wall connecting the first side wall and the second side wall, the front wall, the first side wall, the second side wall and the rear wall forming a frame.

8. The mixing chamber assembly of claim 1, wherein: the mixing assembly comprises a second mixing assembly positioned in the second cavity, and the second mixing assembly comprises an omega-shaped swirl plate positioned at the bottom of the second mixing assembly and a guide plate positioned on the upper part of the omega-shaped swirl plate.

9. The mixing chamber assembly of claim 8, wherein: the guide plate comprises a first inclined plate and a second inclined plate, and the first inclined plate and the second inclined plate are arranged in a splayed shape; or the guide plate is C-shaped.

10. The utility model provides an exhaust aftertreatment device, its includes first aftertreatment carrier subassembly, second aftertreatment carrier subassembly, is located the third aftertreatment carrier subassembly of the upper reaches of first aftertreatment carrier subassembly and connects first aftertreatment carrier subassembly with the mixing chamber subassembly of second aftertreatment carrier subassembly, wherein first aftertreatment carrier subassembly is diesel particulate trap, second aftertreatment carrier subassembly is selective catalytic reduction agent, third aftertreatment carrier subassembly is diesel oxidation catalyst converter, its characterized in that: the mixing chamber assembly of any one of claims 1 to 9.