WO2017084549A1

WO2017084549A1 - Mixer and mixing components thereof

Info

Publication number: WO2017084549A1
Application number: PCT/CN2016/105817
Authority: WO
Inventors: 殷雷; 郑祥; 赵治国
Original assignee: 天纳克（苏州）排放系统有限公司
Priority date: 2015-11-18
Filing date: 2016-11-15
Publication date: 2017-05-26
Also published as: CN205117466U

Abstract

A mixer (2) and a mixing assembly (100) thereof for mixing urea droplets with engine exhaust gas. Said mixer (2) comprises: a support (20) and a plurality of plates (21, 22, 23, 24, 25) fixed to the support and arranged in a stacked manner, the plate comprising a plate-like portion (211, 221, 231, 241, 251) and an inclined portion (212, 222, 232, 242, 252) extending obliquely from the plate-like portion toward the downstream direction of the exhaust gas; said inclined portion is for achieving sufficient mixing of the urea droplets with the exhaust gas of the engine; and said plate further comprises a tail fin (213, 223, 233, 243, 253) extending horizontally from said inclined portion toward the said downstream direction of the exhaust gas. With such arrangement, gas flow can pass smoothly through the mixer, thereby decreasing backflow, reducing the risk of forming a liquid film, and hence not easy to form urea crystals.

Description

Mixer and its hybrid components

Priority is claimed on Japanese Patent Application No. 201520921054.1, the entire disclosure of which is hereby incorporated herein in

Technical field

The invention relates to a mixer and a mixing assembly thereof, and belongs to the technical field of engine exhaust aftertreatment.

Background technique

Studies have shown that the uniformity of ammonia distribution in the exhaust aftertreatment system (eg, selective catalytic reduction system, SCR system) has an important impact on the overall performance and durability of the system. If the ammonia distribution is uneven, it will lead to excessive ammonia in the local area and easy to cause ammonia leakage, while in other thin ammonia regions, the nitrogen oxide (NOx) conversion efficiency is too low. Uneven distribution of ammonia over a long period of time can result in uneven aging of the catalyst, thereby affecting the overall performance of the catalyst. In addition, the uneven distribution of urea droplets may cause the local tube wall or mixed structure temperature to be too low to form crystallization, which may block the exhaust pipe when severe, resulting in a decrease in engine power performance.

In order to reduce the risk of crystallization, the industry has proposed a scheme to increase the mixer. U.S. Patent No. 8,607,555 B2, issued on Dec. 17, 2013, which is incorporated herein incorporated by reference in its entirety in its entire entire entire entire entire entire entire entire entire entire entire entire entire entire portion Each of the sheets includes an inclined piece that protrudes in the exhaust direction and protrudes from the frame. These inclined sheets are used to mix the exhaust gas with the atomized urea solution. However, mixers of this construction have certain disadvantages. For example, when an atomized urea solution flows through the inclined sheets, a backflow is formed on the back surface of the inclined sheets. A low pressure or a negative pressure due to reflow will form a liquid film on the back side of the inclined sheet. It is well known that liquid membranes are inextricably linked to urea crystals. Especially in the case of large flow conditions, this liquid film is extremely easy to form urea crystals.

Therefore, it is necessary to provide a novel mixer and a hybrid assembly thereof to solve the above technical problems.

Summary of the invention

It is an object of the present invention to provide a mixer which is less prone to form urea crystals and a mixing assembly therefor.

In order to achieve the above object, the present invention adopts the following technical solution: a mixer for mixing urea droplets with exhaust gas of an engine, the mixer including a support portion and at least one plate fixed to the support portion a sheet comprising an inclined portion extending obliquely downstream of the exhaust direction, the inclined portion for achieving sufficient mixing of the urea droplets with the exhaust of the engine, the sheet further comprising further from the inclined portion A tail fin that extends horizontally downstream of the exhaust direction.

As a further improvement of the technical solution of the present invention, the plate comprises a plate portion, the inclined portion is formed from the plate portion; the plate is a plurality of plates arranged in a stack, the plurality of plates The first plate includes a first plate-shaped portion extending horizontally, a first inclined portion extending obliquely from the first plate-shaped portion toward a downstream side of the exhausting direction, and An inclined portion further extends to the first tail extending horizontally downstream of the exhaust direction.

As a further improved technical solution of the present invention, the first plate portion is provided with a plurality of first fins formed by upward punching, and the first fins are displayed in three rows along the exhaust direction.

As a further improvement of the present invention, the first inclined portion extends completely beyond the support portion, and the first tail portion is parallel to the first plate portion.

As a further improvement of the technical solution of the present invention, the plurality of plates comprise a second plate below the first plate, the second plate comprises a second plate portion extending horizontally, from the second a second inclined portion that extends obliquely downstream of the exhaust direction and a second tail that extends horizontally downstream from the second inclined portion toward the exhaust direction.

As a further improvement of the present invention, the second plate portion is wider than the first plate portion, and the second plate portion is provided with a plurality of second fins formed by upward punching, the second fins They are displayed in two rows along the exhaust direction.

As a further improved technical solution of the present invention, the second inclined portion completely extends beyond the support portion, the second tail fin is parallel to the second plate portion, and the first tail wing is located in a vertical direction Between the first plate portion and the second plate portion.

As a further improvement of the technical solution of the present invention, the plurality of plates comprise a third plate below the second plate, the third plate comprising a horizontally extending third plate portion, from the third a third inclined portion that extends obliquely downstream of the exhaust direction and a third tail that extends horizontally downstream from the third inclined portion toward the exhaust direction.

As a further improvement of the technical solution of the present invention, the third plate portion is not provided with a fin, the third inclined portion extends beyond the support portion, and the third tail portion is parallel to the third plate portion The second empennage extends beyond the first empennage in the exhaust direction, and the first empennage extends beyond the third empennage in the exhaust direction.

As a further improvement of the technical solution of the present invention, the plurality of plates comprise a fourth plate below the third plate, the fourth plate comprises a fourth plate portion extending horizontally, from the fourth a fourth inclined portion that extends obliquely downstream of the exhaust direction and a fourth tail that extends horizontally downstream from the fourth inclined portion toward the exhaust direction.

As a further improved technical solution of the present invention, the fourth plate portion is not provided with fins, the fourth inclined portion extends beyond the support portion, and the fourth tail portion is parallel to the fourth plate portion The second empennage extends beyond the fourth empennage in the exhaust direction, and the fourth empennage extends beyond the third empennage in the exhaust direction.

As a further improved technical solution of the present invention, the third inclined portion is different from the extending oblique direction of the fourth inclined portion; the third inclined portion is provided with an opening at the middle, and the fourth inclined portion extends through The opening intersects the third inclined portion with the fourth inclined portion.

According to a further improvement of the present invention, the first inclined portion, the second inclined portion, and the third inclined portion both extend in a lower right corner direction, and the fourth inclined portion extends in an upper right corner direction.

As a further improved technical solution of the present invention, the plurality of plates comprise a fifth plate below the fourth plate, the fifth plate comprising a fifth plate portion extending horizontally, from the fifth a fifth inclined portion extending obliquely downstream of the exhaust portion in the exhaust direction and a fifth tail extending horizontally downstream from the fifth inclined portion toward the exhaust direction, the fifth inclined portion being rightward The angular direction extends and is parallel to the fourth inclined portion.

As a further improved technical solution of the present invention, the fifth plate portion is not provided with a fin, and the fifth inclined portion at least partially extends beyond the support portion, the fifth tail portion and the fifth plate portion parallel.

As a further improved technical solution of the present invention, the mixer further includes a horizontal plate fixed on the support portion and located under the fifth plate, the horizontal plate including a side protruding from the support portion a first protruding portion and a second protruding portion protruding from the other side of the supporting portion, the first protruding portion including a first inclined piece protruding in a lower left direction and the first inclined piece located at the first inclined piece a rear portion and a bent portion extending upward from both sides of the first protruding portion; the second protruding portion includes a second inclined piece that protrudes in an upper right direction.

The invention also relates to a mixing assembly comprising a mixing tube, a mixer located within the mixing tube, and a mixing element located within the mixing tube and downstream of the mixer, wherein the mixer is the aforementioned mixer The mixing element is another mixer or an open cell separator.

Compared with the prior art, the present invention allows a smooth flow of airflow by adding a horizontal tail to the plate of the mixer, reduces backflow, reduces the risk of forming a liquid film, and is difficult to form urea crystals.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a mixing assembly of the present invention in a first embodiment.

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

Figure 3 is an exploded perspective view of another angle of Figure 2.

Figure 4 is a perspective view of the mixer of the present invention in the first embodiment.

Figure 5 is a front elevational view of Figure 4;

Figure 6 is a cross-sectional view taken along an angle of Figure 4;

Figure 7 is a left side view of Figure 4;

Figure 8 is a right side view of Figure 4;

Figure 9 is a partially exploded perspective view of the mixer of the present invention.

Figure 10 is an exploded view of the sheet and the cross plate of the mixer of the present invention;

Figure 11 is a perspective view of the mixing element of the present invention in the first embodiment.

Figure 12 is a front elevational view of Figure 11;

Figure 13 is a cross-sectional view taken along an angle of Figure 11;

Figure 14 is a left side view of Figure 11;

Figure 15 is a partially exploded perspective view of the mixing element of the present invention.

Figure 16 is a perspective view of the mixing assembly of the present invention in a second embodiment.

Figure 17 is an exploded perspective view of Figure 16 .

Figure 18 is a perspective view of the mixer of the present invention in the second embodiment.

Figure 19 is an exploded view of the sheet and the cross plate of the mixer of the present invention;

Figure 20 is a front elevational view of the mixer of the present invention;

Figure 21 is a cross-sectional view taken along an angle of Figure 18;

Figure 22 is a left side view of Figure 18;

Figure 23 is a right side view of Figure 18;

Figure 24 is a comparison of the addition of the tail fin and the addition of the tail fin.

detailed description

Referring to Figures 1 to 3, the present invention discloses a mixing assembly 100 comprising a mixing tube 1, a mixer 2 located in the mixing tube 1, and a mixer located in the mixing tube 1 and located in the mixer. 2 downstream mixing elements. Referring to FIG. 2 and FIG. 3, in the first embodiment of the present invention, the mixing element is another mixer 3. The mixing pipe 1 is provided with a urea nozzle mounting portion 11 for mounting a urea nozzle (not shown), and the mixer 2 and the other mixer 3 are located downstream of the urea nozzle mounting portion 11. It will be appreciated that when the mixing assembly 100 of the present invention is installed in an exhaust aftertreatment system, an oxidation catalyst (DOC) and/or a diesel particulate trap (DPF) may be disposed upstream of the mixing assembly 100. A selective catalytic reduction (SCR) may be disposed downstream of the mixing assembly 100.

In operation, the urea nozzle sprays the atomized urea solution into the mixing tube, and the exhaust gas and the urea droplets are first mixed by the mixer 2 and mixed for a second time by the mixing element. As an embodiment of the present invention, the homogeneous mixture after mixing is subjected to selective catalytic reduction (SCR) to cause a reaction to reduce the content of nitrogen oxides.

Referring to Figures 4 to 10, the mixer 2 is used to mix urea droplets with the exhaust of the engine. The mixer 2 includes a support portion 20 and at least one plate fixed to the support portion 20. When the mixer 2 of the present invention is applied to an air-assisted urea injection system, a sheet is feasible. Of course, in the illustrated embodiment of the present invention, the plate is a plurality of plates which are stacked, and the plate includes a first plate 21, a second plate 22, and a second layer which are sequentially stacked in a vertical direction. The three sheets 23, the fourth sheets 24, and the fifth sheets 25 are provided.

The first plate 21 includes a first plate portion 211 extending horizontally in the support portion 20 and a first inclined portion extending obliquely from the first plate portion 211 toward the downstream of the exhaust direction. 212 and a first tail 213 extending horizontally from the first inclined portion 212 to the downstream of the exhaust direction. The first plate portion 211 is provided with a plurality of first fins 2111 formed by upward punching, and the first fins 2111 are displayed in three rows along the exhaust direction. The first inclined portion 212 extends completely beyond the support portion 20 , and the first tail 213 is parallel to the first plate portion 211 .

The second plate 22 includes a second plate portion 221 extending horizontally in the support portion 20 and a second inclined portion extending obliquely from the second plate portion 221 toward the downstream of the exhaust direction. 222 and a second tail 223 extending horizontally from the second inclined portion 222 to the downstream of the exhaust direction. The second plate portion 221 is wider than the first plate portion 211, and the second plate portion 221 is provided with a plurality of second fins 2211 formed by upward pressing, and the second fins 2211 are along the row The gas direction is displayed in two rows. Referring to FIG. 6, the second inclined portion 222 extends completely beyond the support portion 20, the second tail 223 is parallel to the second plate portion 221, and the first tail 213 is in a vertical direction. The upper portion is located between the first plate portion 211 and the second plate portion 221 .

The third plate 23 includes a third plate portion 231 extending horizontally in the support portion 20 and a third inclined portion extending obliquely from the third plate portion 231 toward the downstream of the exhaust direction. 232 and a third tail 233 extending horizontally from the third inclined portion 232 to the downstream of the exhaust direction. The third plate portion 231 is not provided with fins. The third inclined portion 232 partially extends beyond the support portion 20, the third tail 233 is parallel to the third plate portion 231; the second tail 223 extends beyond the first in the exhaust direction The tail fin 213 extends beyond the third tail 233 in the exhaust direction.

The fourth plate 24 includes a fourth plate portion 241 extending horizontally in the support portion 20 and a fourth inclined portion extending obliquely from the fourth plate portion 241 toward the downstream of the exhaust direction. 242 and a fourth tail fin 243 extending horizontally from the fourth inclined portion 242 to the downstream of the exhaust direction. The fourth plate portion 241 is not provided with fins, the fourth inclined portion 242 partially extends beyond the support portion 20, and the fourth tail portion 243 is parallel to the fourth plate portion 241; The two tail fins 223 extend beyond the fourth tail fin 243 in the exhaust direction, and the fourth tail fin 243 extends beyond the third tail fin 233 in the exhaust direction. The third inclined portion 232 is different from the extending oblique direction of the fourth inclined portion 242; the third inclined portion 232 is provided with an opening 2321 located in the middle, and the fourth inclined portion 242 extends through the opening 2321 The third inclined portion 232 and the fourth inclined portion 242 are formed to intersect.

The fifth plate 25 includes a fifth plate portion 251 extending horizontally in the support portion 20 and a fifth inclined portion extending obliquely from the fifth plate portion 251 toward the downstream of the exhaust direction. 252 and a fifth tail 253 extending horizontally from the fifth inclined portion 252 to the downstream of the exhaust direction, the fifth inclined portion 252 extending in the upper right direction and parallel to the fourth inclined portion 242 . The fifth plate portion 251 is not provided with fins, and the fifth inclined portion 252 at least partially extends beyond the support portion 20, and the fifth tail portion 253 is parallel to the fifth plate portion 251.

Referring to FIG. 6 , the first inclined portion 213 , the second inclined portion 222 , and the third inclined portion 232 all extend in a right lower corner direction, the fourth inclined portion 242 and the fifth inclined portion. The portion 252 extends in the upper right direction.

In addition, referring to FIG. 4 to FIG. 6 and FIG. 9 to FIG. 10 , the mixer 2 further includes a horizontal plate 26 fixed on the support portion 20 and located below the fifth plate 25 . The cross plate 26 includes a first protrusion 261 that protrudes from one side (for example, the left side) of the support portion 20 and a second protrusion that protrudes from the other side (for example, the right side) of the support portion 20 Part 262. The first protruding portion 261 includes a first inclined piece 2611 protruding in a lower left direction and a bent portion extending rearward of the first inclined piece 2611 and extending upward from both sides of the first protruding portion 261 The second protrusion 262 includes a second inclined piece 2621 that protrudes in the upper right direction.

For convenience of description, in the present invention, the first plate-shaped portion 211 to the fifth plate-like portion 251 are collectively referred to as a plate-like portion; the first inclined portion 212 to the fifth inclined portion 252 are collectively referred to as an inclined portion; the first rear wing 213 to the first The five-tailed wing 253 is collectively referred to as the tail. Wherein, since the plate-like portion extends horizontally, the turbulence formed by the exhaust gas and/or the urea droplets is small, and in some embodiments, the plate-shaped portion may not be provided.

In use, the mixture of urea droplets and exhaust gas directs the mixture to the inclined portion under the action of the first fin 2111, the second fin 2211, and the plate portion. The inclined portion forms a crossover of the mixture behind the inclined portion to achieve thorough mixing of the urea droplets with the exhaust gas.

The inclined portion has a function of spoiler to uniformly mix the mixture. The inclination angles, directions, and positional relationship of the first inclined portion 212 to the fifth inclined portion 252 are obtained by optimization by means of CFD. In addition, the direction, the length, and the positional relationship between the first and second tail fins 213 to 253 are also the regions of the present invention. Different from the existing technology.

The mixer of the present invention having a tail fin and the mixer without the tail fin were tested under the following conditions.

The experimental results are as follows:

Referring to Fig. 24, the present invention allows a smooth flow of airflow by adding a horizontal tail to the plate of the mixer 1, reducing backflow, reducing the risk of forming a liquid film, and making it difficult to form urea crystals.

Referring to Figures 11 through 15, another mixer 3 is similar to the mixer 2, but no tail is provided. The other mixer 3 includes a second support portion 30 and a plurality of plates fixed in the second support portion 30. The sheet includes a sixth sheet 31, a seventh sheet 32, an eighth sheet 33, a ninth sheet 34, and a tenth sheet 35 which are sequentially laminated in the vertical direction. Each of the plates is provided with a plurality of fins and an inclined portion extending from the second support portion.

Referring to Figures 16 to 23, the present invention also discloses a mixing assembly 200 comprising a mixing tube 1, a mixer 4 located in the mixing tube 1, and a mixing tube 1 located in the mixing tube 1 and located in the mixing Mixing element downstream of the device 4. In a second embodiment of the invention, the mixing element is an apertured partition 5. In the description of the embodiments of the present invention, the same reference numerals denote the same structures. In view of the fact that the mixer 4 and the mixer 2 are substantially identical, and those skilled in the art can clearly understand the difference between the two by observing the drawings, no further details are provided herein.

In addition, the above embodiments are only for illustrating the present invention and are not intended to limit the technical solutions described in the present invention. The understanding of the present specification should be based on those skilled in the art, although the present specification has been carried out with reference to the above embodiments. DETAILED DESCRIPTION OF THE INVENTION However, those skilled in the art should understand that the invention may be modified or equivalently substituted without departing from the spirit and scope of the invention. It is intended to be included within the scope of the appended claims.

Claims

A mixer for mixing urea droplets with exhaust gas of an engine, the mixer including a support portion and at least one plate fixed to the support portion, the plate including the exhaust direction a slope extending obliquely downstream, the inclined portion for achieving sufficient mixing of the urea droplets with the exhaust of the engine, characterized in that the sheet further includes a downstream from the inclined portion further toward the exhaust direction Horizontally extending tail.
The mixer according to claim 1, wherein said plate comprises a plate portion, said inclined portion being formed from said plate portion; said plate being a plurality of plates stacked in a stack, The plurality of plates include a first plate, the first plate including a first plate portion extending horizontally, and a first inclined portion extending obliquely from the first plate portion toward a downstream of the exhaust direction And a first tail extending horizontally from the first inclined portion to the downstream of the exhaust direction.
The mixer according to claim 2, wherein said first plate portion is provided with a plurality of first fins formed by upward punching, and said first fins are displayed in three rows along said exhaust direction.
A mixer according to claim 2, wherein said first inclined portion extends completely beyond said support portion, said first tail portion being parallel to said first plate portion.
A mixer according to claim 2, wherein said plurality of plates comprise a second plate below said first plate, said second plate comprising a second plate portion extending horizontally, a second inclined portion that extends obliquely downstream from the second plate portion toward the exhaust direction and a second tail portion that extends horizontally further from the second inclined portion toward the downstream of the exhaust direction.
The mixer according to claim 5, wherein said second plate portion is wider than said first plate portion, and said second plate portion is provided with a plurality of second fins formed by upward punching. These second fins are displayed in two rows along the exhaust direction.
A mixer according to claim 5, wherein said second inclined portion extends completely beyond said support portion, said second rear wing is parallel to said second plate portion, and said first rear wing is vertical Located between the first plate portion and the second plate portion in the straight direction.
A mixer according to claim 5, wherein said plurality of plates comprise a third plate below said second plate, said third plate comprising a third plate portion extending horizontally, a third inclined portion that extends obliquely from the third plate portion toward the downstream of the exhaust direction and a third tail portion that extends horizontally from the third inclined portion to the downstream of the exhaust direction.
A mixer according to claim 8, wherein said third plate portion is not provided with fins, said third inclined portion extending beyond said support portion, said third tail portion and said first The three slabs are parallel; the second empennage extends beyond the first empennage in the exhaust direction, and the first empennage extends beyond the third empennage in the exhaust direction.
A mixer according to claim 8 wherein said plurality of panels comprise a fourth panel below said third panel, said fourth panel comprising a fourth panel extending horizontally, a fourth inclined portion extending obliquely from the fourth plate portion toward the downstream of the exhaust direction and a downstream level further from the fourth inclined portion toward the exhaust direction Extended fourth tail.
A mixer according to claim 10, wherein said fourth plate portion is not provided with fins, said fourth inclined portion extends beyond said support portion, said fourth tail portion and said first The four slabs are parallel; the second empennage extends beyond the fourth empennage in the exhaust direction, and the fourth empennage extends beyond the third empennage in the exhaust direction.
The mixer according to claim 11, wherein said third inclined portion is different from an extending oblique direction of said fourth inclined portion; said third inclined portion is provided with an opening in the middle, said fourth The inclined portion extends through the opening such that the third inclined portion and the fourth inclined portion intersect.
The mixer according to claim 11, wherein said first inclined portion, said second inclined portion, and said third inclined portion both extend in a lower right corner direction, said fourth inclined portion to an upper right corner The direction extends.
A mixer according to claim 13 wherein said plurality of panels comprise a fifth panel below said fourth panel, said fifth panel comprising a fifth panel extending horizontally, a fifth inclined portion extending obliquely from the fifth plate portion toward the downstream of the exhaust direction, and a fifth tail portion extending horizontally from the fifth inclined portion to the downstream of the exhaust direction, the first The five inclined portions extend in the upper right corner direction and are parallel to the fourth inclined portion.
A mixer according to claim 14 wherein said fifth plate portion is not provided with fins, said fifth inclined portion extending at least partially beyond said support portion, said fifth tail portion being said The fifth plate-like portion is parallel.
A mixer according to claim 14 wherein said mixer further comprises a transverse plate secured to said support portion and below said fifth plate, said transverse plate comprising said support a first protruding portion on one side of the portion and a second protruding portion protruding from the other side of the supporting portion, the first protruding portion including a first inclined piece protruding in a lower left direction and located at the a bent portion extending rearward of the first inclined piece and extending from both sides of the first protruding portion; the second protruding portion includes a second inclined piece that protrudes in an upper right direction.
A mixing assembly comprising a mixing tube, a mixer located within the mixing tube, and a mixing element located within the mixing tube and downstream of the mixer, wherein the mixer is in accordance with claims 1 to 16. In the mixer of any of the preceding claims, the mixing element is another mixer or an apertured separator.