CN214787625U

CN214787625U - SCR system and SCR mixer

Info

Publication number: CN214787625U
Application number: CN202023023153.8U
Authority: CN
Inventors: 卞增涛; 刘兴龙; 李俊普; 李昭阳
Original assignee: Weichai Power Co Ltd; Weichai Power Emission Solutions Technology Co Ltd
Current assignee: Weichai Power Co Ltd; Weichai Power Emission Solutions Technology Co Ltd
Priority date: 2020-12-15
Filing date: 2020-12-15
Publication date: 2021-11-19
Anticipated expiration: 2030-12-15

Abstract

The utility model discloses a SCR system and SCR blender, SCR blender include outer tube, one-level whirl subassembly and second grade whirl subassembly. The SCR mixer of this scheme discloses realizes mixing the first step of urea and waste gas through one-level whirl subassembly, through the pyrolysis of second grade whirl subassembly acceleration urea, and the ammonia that the pyrolysis produced mixes with the second step that waste gas goes on, has effectively improved the degree of consistency that waste gas and ammonia mix, promotes the performance of SCR mixer, reduces the NO in the waste gas_XThe content is high, and the temperature of the spiral blade of the second-stage rotational flow component is high, so that the urea can be prevented from crystallizing and falling in the SCR mixerLow risk of failure of the SCR mixer.

Description

SCR system and SCR mixer

Technical Field

The utility model relates to the technical field of engines, in particular to SCR system and SCR blender.

Background

With the upgrading of road and non-road emission regulations, NO_XThe emission requirements are gradually increased. However, under the working condition of low temperature and low discharge capacity, the urea in the SCR mixer can not be effectively evaporated to decompose ammonia gas, so that the ammonia gas can not be uniformly mixed with the waste gas, and NO in the waste gas_XThe content exceeds the standard, and meanwhile, part of urea is attached to an SCR mixer to form crystals, so that SCR is invalid.

Thus, how to promote the evaporation of urea to avoid NO in the exhaust gas_XThe content exceeds the standard, and the risk of urea crystallization on an SCR mixer is reduced, so that the technical problem to be solved urgently by the technical personnel in the field is solved.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a SCR blender to promote urea evaporation, avoid NO in the waste gas_XThe content exceeds the standard, and the risk of urea crystallization on an SCR mixer is reduced. The utility model also provides a SCR system.

In order to achieve the above object, the utility model provides a following technical scheme:

an SCR mixer, comprising:

an outer tube;

the primary cyclone assembly is arranged at the air inlet end of the outer pipe;

the second grade whirl subassembly is located the low reaches of one-level whirl subassembly, the second grade whirl subassembly includes bracing piece, helical blade and inner tube, and wherein the inner tube is installed in the outer tube and with the outer tube is coaxial to be arranged, the inner tube with outer tube interference fit, the bracing piece is located in the inner tube, helical blade follows the length direction of bracing piece sets up, helical blade's outer fringe can with the inner wall of inner tube offsets.

Preferably, in above-mentioned SCR blender, one-level whirl subassembly is the whirl pipe, the whirl pipe includes body and whirl board, the body is located in the outer tube and with the outer tube is coaxial to be arranged, seted up on the pipe wall of body along the axis direction of body sets up rectangular shape through-hole, the whirl board is installed on the pipe wall of body and with rectangular shape through-hole one-to-one, the whirl board is located one side of the length extending direction of rectangular shape through-hole, and towards the slope of rectangular shape through-hole.

Preferably, in the SCR mixer, the plurality of swirl plates have the same inclination direction, and the plurality of swirl plates have the same inclination angle.

Preferably, in the SCR mixer, an inclination angle of the swirl plate is 45 ° to 60 °.

Preferably, in the SCR mixer, the tube body is mounted on the outer tube through a partition plate, a mounting hole matched with the tube body is formed in the partition plate, the tube body is inserted into the mounting hole, the periphery of the partition plate is in interference fit with the outer tube, a circle of through hole is formed in the partition plate at a position close to the mounting hole, and the through hole is used for preventing an airflow dead zone from being formed.

Preferably, in the SCR mixer, the through-hole is a rectangular through-hole.

Preferably, in the SCR mixer described above, the length of the pipe body is at most equal to the length of the inner pipe.

Preferably, in the SCR mixer, a distance between the first cyclone assembly and the second cyclone assembly is 1 to 3 cm.

Preferably, in the SCR mixer, the helical blade is a stainless steel helical blade.

An SCR system comprising an SCR mixer according to any one of the above aspects.

According to the above technical scheme, the utility model provides a SCR blender, including outer tube, one-level whirl subassembly and second grade whirl subassembly. This scheme discloses an SCR blender realizes mixing the first step of urea and waste gas through one-level whirl subassembly, through the pyrolysis of second grade whirl subassembly acceleration urea, the ammonia and the waste gas of pyrolysis productionThe second step of mixing effectively improves the mixing uniformity of the waste gas and the ammonia gas, improves the performance of the SCR mixer, and reduces NO in the waste gas_XThe content, the temperature of the helical blade of second grade whirl subassembly is high simultaneously, can avoid urea to take place the crystallization in the SCR blender, reduces the risk that the SCR blender became invalid.

The scheme also discloses an SCR system which comprises an SCR mixer, wherein the SCR mixer is the SCR mixer recorded in any scheme. Since the SCR mixer has the above technical effects, the SCR system having the SCR mixer also has the same technical effects, and will not be described herein again.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an SCR system according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an SCR mixer according to an embodiment of the present invention;

fig. 3 is a schematic structural view of a swirl tube according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a partition board provided in an embodiment of the present invention;

fig. 5 is a schematic structural view of the helical blade and the supporting plate according to an embodiment of the present invention.

Wherein the content of the first and second substances,

1. outer tube, 2, first grade whirl subassembly, 3, second grade whirl subassembly, 31, bracing piece, 32, helical blade, 33, inner tube, 4, baffle.

Detailed Description

The utility model discloses a SCR mixer to promote urea evaporation, avoid NO in the waste gas_XThe content exceeds the standard, and simultaneously, the urea mixing in SCR is reducedRisk of crystallization on the vessel. The utility model also provides a SCR system.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Please refer to fig. 1-5.

The utility model discloses a SCR blender, including outer tube 1, one-level whirl subassembly 2 and second grade whirl subassembly 3.

The first-stage cyclone assembly 2 and the second-stage cyclone assembly 3 are both arranged in the outer pipe 1.

The primary cyclone assembly 2 is installed at the air inlet end of the outer pipe 1. Waste gas enters the first-stage cyclone assembly 2 from the air inlet end of the outer pipe 1 and is intensively mixed with urea spray sprayed into the first-stage cyclone assembly 2.

A secondary cyclone assembly 3 is mounted within the outer tube 1 and downstream of the primary cyclone assembly 2. Secondary cyclone assembly 3 comprises support bar 31, helical blades 32 and inner tube 33. As shown in fig. 1, 2 and 5, the inner tube 33 is installed in the outer tube 1, the inner tube 33 is coaxially arranged with the outer tube 1 and is in interference fit with the outer tube 1, the support rod 31 is located in the inner tube 33, the support rod 31 is used for supporting and installing the helical blade 32, the helical blade 32 is arranged along the length direction of the support rod 31, the outer edge of the helical blade 32 can abut against the inner wall of the inner tube 33, and the support rod 31 and the helical blade 32 are installed and fixed in the inner tube 33. The helical blade 32 is preferably a stainless steel helical blade 32, and has a thermal conductivity higher than that of air, and the helical blade 32 with a high temperature enables urea droplets on the helical blade 32 to be rapidly evaporated and pyrolyzed into ammonia gas. The second grade whirl subassembly 3 can avoid the urea crystallization, reduces the risk that SCR became invalid, and helical blade 32 can make ammonia and waste gas form the second grade whirl simultaneously, promotes the mixture of ammonia and waste gas, improves the homogeneity that ammonia and waste gas mix, makes the performance of SCR blender obtain promoting.

The SCR mixer of this scheme discloses realizes mixing the first step of urea and waste gas through one-level whirl subassembly 2, through the pyrolysis of second grade whirl subassembly 3 acceleration urea, and the ammonia that the pyrolysis produced mixes with the second step that waste gas goes on, has effectively improved the degree of consistency that waste gas and ammonia mix, promotes the performance of SCR mixer, reduces the NO in the waste gas_XThe content, the temperature of the helical blade 32 of second grade whirl subassembly 3 is high simultaneously, can avoid urea to take place the crystallization in the SCR mixer, reduces the risk that the SCR mixer became invalid.

In one embodiment of the present solution, as shown in fig. 3, the primary cyclone assembly 2 is a cyclone tube.

The cyclone tube comprises a tube body and a cyclone plate. The tube body is located in the outer tube 1 and arranged coaxially with the outer tube 1. The tube wall of the tube body is provided with strip-shaped through holes arranged along the axis direction of the tube body, and the rotational flow plates are arranged on the tube wall of the tube body and are in one-to-one correspondence with the strip-shaped through holes on the tube body. As shown in fig. 3, the swirling plate is located on one side of the length extending direction of the elongated through hole and is inclined towards the plane where the elongated through hole is located.

Waste gas gets into the whirl pipe from the inlet end of outer tube 1 in, under the effect of whirl board and rectangular shape through-hole, forms strong whirl disturbance, takes place the violent mixture with the urea that spouts into the whirl pipe, makes the urea liquid drop disperse, takes place the secondary breakage, forms the liquid drop of littleer diameter, changes the evaporation, is difficult for taking place the crystallization in the SCR blender.

After urea liquid drops passing through the first-stage cyclone assembly 2 fall onto the helical blade 32 of the second-stage cyclone assembly 3, the helical blade 32 with high temperature can rapidly evaporate and pyrolyze the urea liquid drops to form ammonia gas. The second-stage cyclone component 3 effectively promotes the mixing of ammonia gas and waste gas, improves the uniformity of ammonia gas distribution and improves the performance of the SCR mixer.

Preferably, the inclination directions of the plurality of swirl plates relative to the axis of the pipe body are the same, and the inclination angles of the plurality of swirl plates are the same.

The inclination angle of the cyclone plate is 45-60 degrees.

The body passes through baffle 4 to be installed on outer tube 1 in this scheme.

Set up on baffle 4 with body complex mounting hole, the body inserts in the mounting hole, the periphery and the 1 interference fit of outer tube of baffle 4.

The baffle 4 acts as a seal to prevent the flow of air from moving towards the secondary cyclone 3 and forcing the air into the cyclone tube to mix with the urea spray.

A circle of through holes are formed in the position, close to the mounting hole, of the partition plate 4, and are used for preventing an airflow dead zone from being formed in the position, and the risk of urea crystallization in the SCR mixer is further reduced.

In a specific embodiment of the present solution, the through hole is a rectangular through hole.

The through-holes are not limited to rectangular through-holes, but may be circular, triangular, or other polygonal through-holes.

The length of the tube body is at most equal to the length of the inner tube 33. The inner pipe 33 is long, so that the time for pyrolysis of urea in the secondary cyclone assembly 3 can be prolonged, and the performance of the SCR mixer is further improved.

In one embodiment of the present solution, the distance between the first cyclone assembly and the second cyclone assembly is 30-50 mm. The diameter of the first cyclone assembly is smaller than that of the second cyclone assembly, so that the back pressure is reduced.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An SCR mixer, comprising:

an outer tube (1);

the primary cyclone assembly (2) is arranged at the air inlet end of the outer pipe (1);

second grade whirl subassembly (3), be located the low reaches of one-level whirl subassembly (2), second grade whirl subassembly (3) are including bracing piece (31), helical blade (32) and inner tube (33), wherein inner tube (33) are installed in outer tube (1) and with outer tube (1) coaxial arrangement, inner tube (33) with outer tube (1) interference fit, bracing piece (31) are located in inner tube (33), helical blade (32) are followed the length direction of bracing piece (31) sets up, the outer fringe of helical blade (32) can with the inner wall of inner tube (33) offsets.

2. The SCR mixer of claim 1, wherein the first-stage cyclone assembly (2) is a cyclone tube, the cyclone tube comprises a tube body and a cyclone plate, the tube body is positioned in the outer tube (1) and coaxially arranged with the outer tube (1), the tube wall of the tube body is provided with a strip-shaped through hole along the axial direction of the tube body, the cyclone plate is installed on the tube wall of the tube body and in one-to-one correspondence with the strip-shaped through hole, and the cyclone plate is positioned on one side of the length extending direction of the strip-shaped through hole and inclines towards the strip-shaped through hole.

3. The SCR mixer of claim 2, wherein the plurality of swirl plates are inclined in the same direction, and the plurality of swirl plates are inclined at the same angle.

4. An SCR mixer as claimed in claim 3, wherein the angle of inclination of the swirl plates is 45 ° -60 °.

5. The SCR mixer according to claim 2, wherein the pipe body is mounted on the outer pipe (1) through a partition plate (4), the partition plate (4) is provided with a mounting hole matched with the pipe body, the pipe body is inserted into the mounting hole, the periphery of the partition plate (4) is in interference fit with the outer pipe (1), and a circle of through holes are arranged on the partition plate (4) close to the mounting hole and used for preventing the formation of an airflow dead zone.

6. The SCR mixer of claim 5, wherein the through-holes are rectangular through-holes.

7. -SCR mixer according to claim 2, characterized in that the length of the pipe body is at most equal to the length of the inner pipe (33).

8. An SCR mixer according to claim 1, characterized in that the distance between the primary cyclone assembly (2) and the secondary cyclone assembly (3) is 1-3 cm.

9. An SCR mixer according to claim 1, characterized in that the helical blade (32) is a stainless steel helical blade (32).

10. An SCR system comprising an SCR mixer according to any one of claims 1 to 9.