CN213450557U

CN213450557U - Mixing chamber subassembly and tail gas aftertreatment encapsulation

Info

Publication number: CN213450557U
Application number: CN202022662158.9U
Authority: CN
Inventors: 吴涛涛; 凌睿; 严才宝; 王长林; 郑鑫
Original assignee: Tenneco Suzhou Emission System Co Ltd
Current assignee: Tenneco Suzhou Emission System Co Ltd
Priority date: 2020-11-17
Filing date: 2020-11-17
Publication date: 2021-06-15
Anticipated expiration: 2030-11-17

Abstract

A mixing chamber assembly and an exhaust aftertreatment package include a mixing chamber housing and a mixing tube assembly. The mixing tube assembly comprises a swirl tube and a diffusion cone connected with the swirl tube. The diffusion cone is provided with a first port connected with the cyclone tube and a second port far away from the first port, and the area of the first port is smaller than that of the second port. The utility model discloses still disclose the tail gas aftertreatment subassembly including above-mentioned hybrid chamber subassembly. Compared with the prior art, the utility model discloses a set up the diffusion awl, increased the volume that is used for carrying out the hybrid mixing chamber with tail gas and urea liquid drop, promoted anti crystallization ability.

Description

Mixing chamber subassembly and tail gas aftertreatment encapsulation

Technical Field

The utility model relates to a hybrid chamber subassembly and tail gas aftertreatment encapsulation belongs to engine exhaust aftertreatment technical field.

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

An object of the utility model is to provide a better hybrid chamber subassembly of anti urea crystallization ability and tail gas aftertreatment encapsulation.

In order to achieve the above purpose, the utility model adopts the following technical scheme: a mixing cavity assembly comprises a mixing cavity shell and a mixing tube 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 pipe assembly comprises a cyclone pipe positioned in the first cavity and a diffusion cone positioned in the first cavity and connected with the cyclone pipe; the cyclone tube is provided with a first inner cavity, a plurality of cyclone plates and an airflow inlet corresponding to the cyclone plates, and the first inner cavity is communicated with the first cavity through the airflow inlet; the diffusion cone is provided with a first port connected with the cyclone tube and a second port far away from the first port, the area of the first port is smaller than that of the second port, and the second port is communicated with the second cavity.

As a further improved technical scheme of the utility model, the mixing chamber casing is equipped with the mount pad that is used for installing the urea nozzle, the urea nozzle be used for to spray atomizing urea liquid drop in the whirl pipe.

As a further improved technical scheme of the utility model, the mixing chamber casing is equipped with and is located first cavity with baffle between the second cavity.

As a further improved technical scheme of the utility model, the second port is fixed in on the baffle.

As a further improved technical scheme of the utility model, the hybrid chamber subassembly is including being located in the second cavity and being located the tip subassembly of the bottom of second port, the tip subassembly include the diapire, from the perisporium of the diapire upwards extending all around and by the diapire with the cushion chamber that the perisporium encloses jointly.

As a further improved technical solution of the present invention, the peripheral wall is provided with a first side wall facing the second aftertreatment carrier assembly, the first side wall is provided with a plurality of first airflow perforations through which the airflow flows.

As the utility model discloses further modified technical scheme, the mixed pipe subassembly is including being located the broken pipe of urea in the first interior cavity, the broken pipe of urea is along axial extension, be equipped with the broken groove of a plurality of urea on the outer wall of the broken pipe of urea, the broken groove of urea is followed axial length is greater than along the perpendicular to axial radial width.

The utility model also discloses a tail gas aftertreatment encapsulation, it includes first aftertreatment carrier subassembly, second aftertreatment carrier subassembly, is located the third aftertreatment carrier subassembly and the connection in the upper reaches of first aftertreatment carrier subassembly with the hybrid chamber subassembly of second aftertreatment carrier subassembly, wherein first aftertreatment carrier subassembly is diesel particle trap, second aftertreatment carrier subassembly is selective catalytic reduction agent, third aftertreatment carrier subassembly is diesel oxidation catalyst converter, the hybrid chamber subassembly is aforementioned hybrid chamber subassembly.

Compared with the prior art, the utility model discloses a set up the diffusion awl, increased the volume that is used for carrying out the hybrid mixing chamber with tail gas and urea liquid drop, promoted anti crystallization ability.

Drawings

Fig. 1 is a schematic diagram of the exhaust aftertreatment package of the present invention.

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

Fig. 3 is a partially exploded perspective view of fig. 2.

FIG. 4 is a schematic perspective view of the cyclone tube, urea break tube, diffusion cone and baffle of FIG. 2 assembled together.

Fig. 5 is an exploded perspective view of fig. 4.

Fig. 6 is a front view of the urea break pipe of fig. 5.

Fig. 7 is a schematic sectional view taken along line a-a in fig. 2.

Detailed Description

Referring to fig. 1, the present invention discloses an exhaust gas aftertreatment package, which includes a first aftertreatment carrier assembly 1, a second aftertreatment carrier assembly 2, a third aftertreatment carrier assembly 3 located at the 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 an embodiment of the present invention, the first aftertreatment carrier assembly 1 is a diesel particulate trap (DPF), the second aftertreatment carrier assembly 2 is a Selective Catalytic Reduction (SCR), and the third aftertreatment carrier assembly 3 is a Diesel Oxidation Catalyst (DOC).

Referring to fig. 2 to 7, in the illustrated embodiment of the present invention, the mixing chamber assembly 4 includes a mixing chamber housing 5 and a mixing tube assembly 6 installed in the mixing chamber housing 5. The mixing chamber housing 5 is provided with a first opening 51 for communicating with a first aftertreatment carrier assembly 1, a second opening 52 for communicating with a second aftertreatment carrier assembly 2, a first cavity 53 communicating with the first opening 51, a second cavity 54 communicating with the second opening 52, and a partition 55 between the first cavity 53 and the second cavity 54.

The mixing tube assembly 6 comprises a cyclone tube 61 positioned in the first cavity 53, a diffusion cone 66 positioned in the first cavity 53 and connected with the cyclone tube 61, and a urea crushing tube 64 installed in the cyclone tube 61.

The cyclone tube 61 is provided with a first inner cavity 611, a plurality of cyclones 612 and an air inlet 613 corresponding to the cyclones 612. The first inner cavity 611 communicates with the first cavity 53 through the gas flow inlet 613.

The diffuser cone 66 is provided with a first port 661 connected with the cyclone tube 61 and a second port 662 far away from the first port 661, the area of the first port 661 is smaller than that of the second port 662, and the second port 662 is communicated with the second cavity 54. The second port 662 is secured to the bulkhead 55.

The mixing chamber shell 5 is provided with a mounting seat 531 for mounting a urea nozzle 7, and the urea nozzle 7 is used for spraying atomized urea liquid drops into the cyclone tube 61.

In addition, the mixing chamber assembly 4 includes an end assembly 8 located within the second cavity 54 and at the bottom of the second port 662. The end assembly 8 is substantially "boat-shaped". The end assembly 8 includes a bottom wall 81, a peripheral wall 82 extending upwardly from the periphery of the bottom wall 81, and a buffer chamber 83 defined by the bottom wall 81 and the peripheral wall 82. The peripheral wall 82 is provided with a first side wall 821 facing the second aftertreatment carrier assembly 2, a second side wall 822 disposed opposite to the first side wall 821, a first arc-shaped wall 823 between the first side wall 821 and the second side wall 822, and a second arc-shaped wall 824. The first side wall 821 is provided with a plurality of first flow apertures 825 for allowing a mixed flow of off-gas and urea droplets to pass therethrough, thereby facilitating the direction of the mixed flow towards the end face of the downstream second aftertreatment carrier assembly 2. The second side wall 822 is not perforated to avoid dead space by the mixture flow to the side away from the second aftertreatment carrier assembly 2. The first and second

curved walls

823, 824 are configured to swirl the mixed gas flow, thereby increasing the mixing distance and enhancing the evaporation of urea droplets. Preferably, the bottom wall 81 is inclined, and one end of the bottom wall 81 close to the first side wall 821 is lower than one end close to the second side wall 822; with this arrangement, even if a liquid film is formed, the liquid film flows out to the second aftertreatment support element 2 side along the inclined bottom wall 81, thereby preventing urea crystallization due to continuous accumulation of the liquid film. Preferably, the bottom of the first side wall 821 is provided with a diversion channel 826 to facilitate the liquid to flow out; meanwhile, the guide groove 826 can also adjust the uniformity of the mixed air flow when the mixed air flow flows out of the buffer cavity 83.

In addition, the mixing chamber assembly 4 may further include a regulating plate 84 disposed in the buffer chamber 83, and the regulating plate 84 is provided with a plurality of through holes 841, so that further crushing of the urea droplets can be performed. The adjusting plate 84 has a bottom 842, wherein an end of the bottom 842 near the first side wall 821 is lower than an end near the second side wall 822. With this arrangement, even if a liquid film is formed, the liquid film flows out to the second aftertreatment support element 2 side along the inclined bottom 842, thereby preventing urea crystallization due to continuous accumulation of the liquid film.

The mixing chamber assembly 4 is further provided with a gas flow distribution plate 85, the gas flow distribution plate 85 is provided with a plurality of second gas flow perforations 851, and the gas flow distribution plate 85 and the first side wall 821 are located on the same side of the buffer chamber 83. So configured, the mixed gas flow of the exhaust gas and the urea droplets can pass through the first gas flow perforation 825 and the second gas flow perforation 851, thereby facilitating the uniform distribution of the mixed gas flow on the end face of the second aftertreatment carrier assembly 2.

The urea crushing pipe 64 is located in the first inner cavity 611, the urea crushing pipe 64 extends along the axial direction M, a plurality of urea crushing grooves 641 are arranged on the outer wall of the urea crushing pipe 64, and the length L of the urea crushing grooves 641 along the axial direction M is greater than the width W of the urea crushing grooves 641 along the radial direction N perpendicular to the axial direction M. The urea break tank 641 facilitates further breaking up the urea particles into smaller particles, thereby reducing the risk of urea crystallization and improving ammonia uniformity. In addition, when the urea droplets form a liquid film in a part of the urea breaking groove 641, the liquid film can also move along the axial direction M by the blowing of the air flow and/or the gravity. The moving liquid film facilitates the absorption of the temperature of the gas stream and thus the evaporation of itself. The design avoids the liquid film staying in a part for a long time, thereby greatly reducing the risk of urea crystallization. Even if the liquid film accumulated in the urea breaking pipe 64 drops into the end assembly 8 due to the fact that the liquid film cannot be evaporated in time, the liquid film can be broken again through the through hole 841 in the adjusting plate 84, evaporation of urea liquid drops is facilitated, and the risk of urea crystallization is reduced.

The urea breaking pipe 64 is provided with a first end 642, a second end 643 opposite to the first end 642, at least one first fixing claw 644 protruding from the first end 642, and at least one second fixing claw 645 protruding from the second end 643. The first fixed jaw 644 is fixed to one end of the inner wall of the cyclone tube 61, and the second fixed jaw 645 is fixed to the other end of the inner wall of the cyclone tube 61.

When in use, the tail gas of the diesel engine passes through the third aftertreatment carrier component 3 and the first aftertreatment carrier component 1 and enters the first cavity 53 through the first opening 51; most of tail gas is guided by the cyclone plate 612 to rotate and enter the cyclone tube 61; the tail gas and urea liquid drops are mixed in the cyclone tube 61 and form a downward rotating airflow; during the downward flow of the gas flow, the urea liquid drops are further crushed by the urea crushing pipe 64; the mixed gas flow then continues downwards until it reaches the bottom wall 81 of the end module 8; at this time, a part of the mixed gas flow is blocked by the bottom wall 81, and turns around and flows upward; the swirling mixed air flow generates swirling flow along the first arc-shaped wall 823 and the second arc-shaped wall 824, and flows uniformly to the end face of the second aftertreatment carrier assembly 2 through the first air flow penetration holes 825 and the second air flow penetration holes 851.

Compared with the prior art, the utility model discloses a set up diffusion awl 66, increased the volume that is used for carrying out the hybrid mixing chamber with tail gas and urea liquid drop, promoted anti crystallization ability.

The above embodiments are only used for illustrating the present invention and not for limiting the technical solutions described in the present invention, and the understanding of the present specification should be based on the technical personnel in the technical field, and although the present specification has described the present invention in detail with reference to the above embodiments, the skilled personnel in the art should understand that the technical personnel in the technical field can still modify or substitute the present invention, and all the technical solutions and modifications thereof that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A mixing cavity assembly comprises a mixing cavity shell and a mixing tube 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 pipe assembly comprises a cyclone pipe positioned in the first cavity and a diffusion cone positioned in the first cavity and connected with the cyclone pipe; the cyclone tube is provided with a first inner cavity, a plurality of cyclone plates and an airflow inlet corresponding to the cyclone plates, and the first inner cavity is communicated with the first cavity through the airflow inlet; the diffusion cone is provided with a first port connected with the cyclone tube and a second port far away from the first port, the area of the first port is smaller than that of the second port, and the second port is communicated with the second cavity.

2. The mixing chamber assembly of claim 1, wherein: the mixing chamber shell is provided with a mounting seat for mounting a urea nozzle, and the urea nozzle is used for spraying atomized urea liquid drops into the cyclone tube.

3. The mixing chamber assembly of claim 1, wherein: the mixing cavity shell is provided with a partition plate positioned between the first cavity and the second cavity.

4. The mixing chamber assembly of claim 3, wherein: the second port is fixed to the partition.

5. The mixing chamber assembly of claim 4, wherein: the mixing cavity assembly comprises an end assembly which is positioned in the second cavity and at the bottom of the second port, and the end assembly comprises a bottom wall, a peripheral wall and a buffer cavity, wherein the peripheral wall extends upwards from the periphery of the bottom wall, and the buffer cavity is enclosed by the bottom wall and the peripheral wall.

6. The mixing chamber assembly of claim 5, wherein: the peripheral wall is provided with a first side wall facing the second aftertreatment carrier assembly, and the first side wall is provided with a plurality of first airflow perforations through which airflow flows.

7. The mixing chamber assembly of claim 1, wherein: mix the pipe assembly including being located the broken pipe of urea in the first interior cavity, the broken pipe of urea extends along the axial, be equipped with the broken groove of a plurality of urea on the outer wall of the broken pipe of urea, the broken groove of urea is followed axial length is greater than along the perpendicular to axial radial width.

8. An exhaust aftertreatment package comprising a first aftertreatment carrier component, a second aftertreatment carrier component, a third aftertreatment carrier component located upstream of the first aftertreatment carrier component, and a mixing chamber component connecting the first aftertreatment carrier component with the second aftertreatment carrier component, wherein the first aftertreatment carrier component is a diesel particulate trap, the second aftertreatment carrier component is a selective catalytic reduction agent, the third aftertreatment carrier component is a diesel oxidation catalyst, characterized in that: the mixing chamber assembly of any one of claims 1 to 7.