Diesel engine aftertreatment device

Abstract

The utility model provides a diesel engine aftertreatment device and belongs to the field of waste gas treatment. Comprising a shell, a urea injection orifice, a tail gas inlet, a tail gas outlet, a rotational flow pipe fixed on the inner side of the shell, and a partition plate arranged on the bottom side of the rotational flow pipe, the inner cylinder is arranged on the bottom side of the cyclone pipe, a plurality of first vent holes are evenly formed in the bottom side of the circumferential side face of the inner cylinder, a protruding structure is fixed to the bottom face of the inner cylinder in a sealed mode, and the height H of the protruding structure is larger than the first vent holes h; and the outer cylinder is arranged on the outer side of the inner cylinder and fixed to the bottom side of the partition plate, and second vent holes are evenly formed in the top side of the peripheral side face. Through the multiple cavities, the retention time of tail gas and a urea solution in the shell is prolonged, the uniform mixing of the tail gas and the urea solution is improved, the conversion efficiency is improved, and the risk of urea crystallization can be reduced; and through volume contraction and expansion of the multiple cavities, repeated silencing of the gas is achieved, and the noise of the gas is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of exhaust gas treatment, in particular to a diesel engine post-treatment device. Background Art

[0002] The diesel engine aftertreatment device, namely the SCR system, includes a mixer and a reactor. The mixer is connected to the exhaust pipe of the diesel engine and the reactor respectively, and a urea nozzle is arranged in the mixer. The urea sprayed from the nozzle undergoes a certain hydrolysis and pyrolysis reaction in the mixer to generate ammonia, and at the same time, after mixing with the exhaust gas containing NOx in the mixer, it flows into the reactor for reduction reaction.

[0003] Patent No. CN215633261U discloses a urea mixer and a DOC-DPF-SCR post-treatment device, including an intake cyclone, which includes a tube body. Along the extension direction of the axial centerline of the tube body, one end of the tube body forms a urea injection end for connecting to a urea injection assembly, and a port at the other end of the tube body forms an air outlet; along the circumference of the tube body, a plurality of air inlets are provided on the tube wall of the tube body at intervals, and swirl blades are provided on the outside of the tube body; a swirl disk is located on the inner side of the end of one end of the air outlet of the tube body, the swirl disk has a plurality of vents, and a plurality of swirl sheets corresponding to the vents are provided on the side of the swirl disk away from the urea injection end of the tube body.

[0004] However, due to the size limitation of the cyclone tube and the shell, the flow path of urea and airflow in the cyclone tube is short, so that the mixing time of urea and airflow is short, and the mixing degree of urea and airflow is affected to a certain extent. Utility Model Content

[0005] In view of the above problems, the utility model provides a diesel engine aftertreatment device.

[0006] A diesel engine aftertreatment device comprises a shell, wherein a urea injection port and an exhaust gas inlet are mounted on the top side of the shell, and an exhaust gas outlet is mounted on the bottom side. The diesel engine aftertreatment device further comprises: a swirl tube fixed on the inner side of the shell, arranged on the bottom side of the urea injection port, and communicated with the urea injection port; a partition plate arranged on the bottom side of the swirl tube, and respectively fixedly connected to the swirl tube and the inner wall of the shell; an inner cylinder arranged on the bottom side of the swirl tube, and fixed on the bottom side of the partition plate, and communicated with the swirl tube; a plurality of first vent holes evenly arranged are opened on the bottom side of the peripheral side surface of the inner cylinder, a raised structure is sealed and fixed on the bottom surface of the inner cylinder, and a height H of the raised structure is higher than the plurality of first vent holes h; an outer cylinder arranged on the outside of the inner cylinder, and fixed on the bottom side of the partition plate, and a plurality of second vent holes evenly arranged are opened on the top side of the peripheral side surface.

[0007] In a preferred embodiment, the outer cylinder has a necked portion in the middle, and the diameter of the necked portion is smaller than the diameters of the two sides of the outer cylinder.

[0008] In a preferred embodiment, the diesel engine after-treatment device further includes: a spiral blade, which is fixed on the outer side of the outer cylinder and arranged inside the necking part.

[0009] In a preferred embodiment, the diesel engine after-treatment device further includes: an annular partition, which is fixedly arranged between the housing and the outer cylinder and is arranged in a staggered parallel arrangement.

[0010] In a preferred embodiment, the diesel engine after-treatment device further includes: an arc-shaped baffle, which is fixedly arranged on the bottom side of the housing and is coaxially arranged with the housing.

[0011] In a preferred embodiment, the housing, the outer cylinder, the inner cylinder, the swirl tube, and the urea injection port are coaxially arranged.

[0012] In a preferred embodiment, the diesel engine after-treatment device further includes: a urea nozzle, which is installed at the urea injection port.

[0013] A diesel engine includes a diesel engine after-treatment device.

[0014] 1. In the diesel engine after-treatment device of the present application, the urea nozzle sprays urea solution into the urea injection port, and the exhaust gas of the diesel engine enters from the exhaust gas inlet. The exhaust gas and the urea solution converge in the swirl tube. Due to the rotation of the swirl tube, the exhaust gas and the urea solution are preliminarily mixed. The mixed gas after preliminary mixing passes through the inner cavity of the inner cylinder, the cavity between the inner cylinder and the outer cylinder, and the cavity between the outer cylinder and the housing, and finally discharges from the exhaust gas outlet. The whole process passes through multiple cavities, which prolongs the residence time of the exhaust gas and the urea solution in the housing, improves the mixing uniformity of the exhaust gas and the urea solution, improves the conversion efficiency, and can reduce the risk of urea crystallization.

[0015] 2. By arranging the convex structure in the diesel engine after-treatment device of the present application, when the exhaust gas and the urea solution flow through the position of the convex structure in the inner cavity of the inner cylinder, as the volume decreases, the gas flow velocity of the exhaust gas and the urea solution is enhanced on the periphery of the convex structure, so that the mixture of the exhaust gas and the urea solution is not easy to form crystal deposits at the bottom of the inner cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Referring to the following description of the exemplary embodiments with reference to the accompanying drawings, other characteristic features and advantages of the present invention will become clear. The drawings incorporated into the specification and constituting a part of the specification illustrate the embodiments of the present invention and are used together with the description to explain the principles of the present invention. In these drawings, like reference numerals are used to represent like elements. The drawings in the following description are some embodiments of the present invention, not all embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 Structural diagram of the diesel engine after-treatment device of the present invention;

[0018] Figure 2 Internal structure diagram of the post-treatment device for a diesel engine of the present utility model;

[0019] Figure 3 Cross-sectional view of the post-treatment device for a diesel engine of the present utility model;

[0020] Figure 4 Enlarged view of position A of the post-treatment device for a diesel engine of the present utility model;

[0021] In the figure: 10, housing; 11, urea injection port; 12, exhaust gas inlet; 13, exhaust gas outlet; 20, cyclone tube; 21, partition plate; 30, inner cylinder; 31, first ventilation hole; 32, convex structure; 40, outer cylinder; 41, second ventilation hole; 42, necking part; 33, spiral blade; 43, annular partition; 22, arc-shaped baffle. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other arbitrarily.

[0023] The post-treatment device for a diesel engine will be described in detail below with reference to the accompanying drawings and embodiments. Embodiment

[0024] A post-treatment device for a diesel engine includes a housing 10. A urea injection port 11 and an exhaust gas inlet 12 are installed on the top side of the housing 10, and an exhaust gas outlet 13 is installed on the bottom side. The post-treatment device for a diesel engine further includes: a cyclone tube 20, fixed inside the housing 10 and disposed under the urea injection port 11, and communicated with the urea injection port 11; a partition plate 21, disposed under the cyclone tube 20 and fixedly connected to the inner wall of the cyclone tube 20 and the housing 10 respectively; an inner cylinder 30, disposed under the cyclone tube 20 and fixed under the partition plate 21, and communicated with the cyclone tube 20. A plurality of first ventilation holes 31 are uniformly provided on the bottom side of the circumferential surface of the inner cylinder 30. A convex structure 32 is fixedly sealed on the bottom surface of the inner cylinder 30, and the height H of the convex structure 32 is higher than the height h of the plurality of first ventilation holes 31; an outer cylinder 40, disposed outside the inner cylinder 30 and fixed under the partition plate 21, and a plurality of second ventilation holes 41 are uniformly provided on the top side of the circumferential surface.

[0025] Among them, the diesel engine after-treatment device further includes: a urea nozzle, which is installed at the urea injection port 11.

[0026] Among them, the housing 10, the outer cylinder 40, the inner cylinder 30, the swirl tube 20, and the urea injection port 11 are coaxially arranged.

[0027] During operation, the urea nozzle injects urea solution into the urea injection port 11, and the diesel engine exhaust gas enters from the exhaust gas inlet 12. The exhaust gas and the urea solution converge in the swirl tube 20. Due to the rotation of the swirl tube 20, the exhaust gas and the urea solution are preliminarily mixed. The preliminarily mixed gas passes through the inner cavity of the inner cylinder 30, the cavity between the inner cylinder 30 and the outer cylinder 40, and the cavity between the outer cylinder 40 and the housing 10, and finally discharges from the exhaust gas outlet 13. The whole process passes through multiple cavities, which prolongs the residence time of the exhaust gas and the urea solution in the housing 10, improves the mixing uniformity of the exhaust gas and the urea solution, and improves the conversion efficiency, and can reduce the risk of urea crystallization.

[0028] At the same time, a convex structure 32 is provided. When the exhaust gas and the urea solution flow through the position of the convex structure 32 in the inner cavity of the inner cylinder 30, as the volume decreases, the flow velocity of the exhaust gas and the urea solution is enhanced on the periphery of the convex structure 32, so that the mixture of the exhaust gas and the urea solution is not easy to form crystal deposits at the bottom of the inner cylinder 30. Embodiment

[0029] Embodiment 2 is an improvement over Embodiment 1. The improvements include: the middle part of the outer cylinder 40 has a necking part 42, and the diameter of the necking part 42 is smaller than the diameters on both sides of the outer cylinder 40.

[0030] Specifically, through the necking part 42, the exhaust gas and the urea mixed solution successively pass through the top-side cavity of the inner cylinder 30, the cavity on the periphery of the convex structure 32 at the bottom side of the inner cylinder 30, the bottom-side cavity of the outer cylinder 40, the necking part 42 of the outer cylinder 40, and the top-side cavity of the outer cylinder 40. The mixed gas undergoes continuous contraction and expansion in volume, thereby realizing multiple noise eliminations of the gas, reducing the noise of the gas, and thus solving the problem of large exhaust noise in the existing after-treatment system. Embodiment

[0031] Embodiment 3 is an improvement over Embodiment 1. The improvements include: the diesel engine after-treatment device further includes: a spiral blade 33, and the spiral blade 33 is fixed on the outer side of the outer cylinder 40 and is arranged inside the necking part 42.

[0032] Among them, by setting the spiral blade 33, a spiral air flow is generated in the necking part 42 for the mixed gas, thereby improving the uniformity of the mixed gas, improving the conversion efficiency, and reducing the risk of urea crystallization. Embodiment

[0033] Embodiment 4 is an improvement over Embodiment 1. The improvements include: The diesel engine aftertreatment device further includes: an annular partition 43, which is fixedly arranged between the housing 10 and the outer cylinder 40 and is arranged in a staggered parallel manner.

[0034] Among them, by arranging the annular partition 43, the mixed gas flows in a staggered manner in the housing 10, thereby prolonging the residence time of the exhaust gas and the urea solution in the housing 10, improving the mixing uniformity of the exhaust gas and the urea solution, improving the conversion efficiency, and reducing the risk of urea crystallization. Embodiment

[0035] Embodiment 5 is an improvement over Embodiment 1. The improvements include: The diesel engine aftertreatment device further includes: an arc-shaped baffle 22, which is fixedly arranged on the bottom side of the housing 10 and is coaxially arranged with the housing 10.

[0036] Among them, by arranging the arc-shaped baffle 22, the flow rate of the mixed gas at the corner of the housing 10 is increased, so that the mixture of the exhaust gas and the urea solution is not likely to form a crystal deposit at the bottom of the inner cylinder 30.

[0037] A diesel engine includes the above-mentioned diesel engine aftertreatment device.

[0038] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such article or device. Without further limitation, the elements defined by the statement "include..." do not exclude the existence of additional identical elements in the article or device including the elements.

[0039] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. The present invention has only been described in detail with reference to the preferred embodiments. Those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and should all be covered within the scope of the claims of the present invention.

Claims

1. A diesel engine aftertreatment device, comprising a housing (10), wherein a urea injection port (11) and an exhaust gas inlet (12) are mounted on the top side of the housing (10), and an exhaust gas outlet (13) is mounted on the bottom side, characterized in that: The diesel engine aftertreatment device also includes: A swirl tube (20) is fixed inside the housing (10) and is disposed at the bottom side of the urea injection port (11) and is in communication with the urea injection port (11); A partition plate (21) is arranged on the bottom side of the cyclone tube (20) and is fixedly connected to the cyclone tube (20) and the inner wall of the housing (10) respectively; An inner cylinder (30) is arranged on the bottom side of the cyclone tube (20) and fixed on the bottom side of the partition plate (21), and is in communication with the cyclone tube (20). A plurality of first vent holes (31) are evenly arranged on the bottom side of the circumferential side of the inner cylinder (30). A raised structure (32) is sealed and fixed on the bottom surface of the inner cylinder (30). The height H of the raised structure (32) is higher than the height h of the plurality of first vent holes (31). The outer cylinder (40) is arranged outside the inner cylinder (30) and fixed to the bottom side of the partition plate (21), and has evenly arranged second ventilation holes (41) formed on the top side of the peripheral side surface; The outer cylinder (40) has a necked portion (42) in the middle, and the diameter of the necked portion (42) is smaller than the diameters of two sides of the outer cylinder (40); The diesel engine aftertreatment device further comprises: The annular partition plates (43) are fixedly arranged between the shell (10) and the outer cylinder (40) and are arranged in a staggered and parallel manner.

2. The diesel engine aftertreatment device according to claim 1, characterized in that: The diesel engine aftertreatment device also includes: A spiral blade (33), wherein the spiral blade (33) is fixed to the outside of the outer cylinder (40) and is arranged inside the necked portion (42).

3. The diesel engine aftertreatment device according to claim 1, characterized in that: The diesel engine aftertreatment device further comprises: The arc-shaped baffle (22) is fixedly arranged on the bottom side of the shell (10) and is coaxially arranged with the shell (10).

4. The diesel engine aftertreatment device according to claim 1, characterized in that: The shell (10), the outer cylinder (40), the inner cylinder (30), the cyclone tube (20), and the urea injection port (11) are coaxially arranged.

5. The diesel engine aftertreatment device according to claim 1, characterized in that: The diesel engine aftertreatment device further comprises: A urea nozzle is installed at the urea injection port (11).

6. A diesel engine, characterized in that: It comprises the diesel engine after-treatment device as described in any one of claims 1-5.

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