Cylinder type rotational flow mixer and post-processing system

Abstract

The utility model provides a cylinder type rotational flow mixer which comprises a cylinder type shell and a rotational flow pipe arranged in an inner cavity of the cylinder type shell, the rotational flow pipe is provided with an upper pipe body and a lower pipe body, the pipe wall of the upper pipe body and the pipe wall of the lower pipe body are both provided with open holes, and the open holes are communicated with the upper pipe body and the lower pipe body. A bottom hole plate and a bottom baffle are installed on a lower pipe opening of the lower pipe body, a plurality of holes are formed in the bottom hole plate, the bottom hole plate is located between the bottom baffle and the lower pipe opening, and an air outlet interval is formed between the bottom hole plate and the bottom baffle. And gas in the rotational flow pipe firstly passes through the holes of the bottom hole plate and then flows out of the rotational flow pipe through the gas outlet interval. The utility model further provides a corresponding post-processing system. Through a barrel type rotational flow mixing and post-processing system, the device can be applied to a national sixth SCR system, and is low in back pressure, good in mixing effect and excellent in anti-crystallization performance.

Description

Technical Field

[0001] This utility model belongs to the field of exhaust gas treatment technology, specifically relating to a cylindrical cyclone mixer and its after-treatment system. Background Technology

[0002] As domestic diesel vehicle emission regulations continue to be upgraded, stricter requirements are being placed on vehicle exhaust after-treatment systems and their core component, the mixer. As a key component of the after-treatment system, the performance of the mixer directly affects NOx emissions.

[0003] The mixer needs to ensure thorough mixing of exhaust gas and the reducing agent (such as urea solution) to improve the conversion efficiency of the SCR system. The mixer also needs good heat exchange performance to ensure that the urea solution rapidly vaporizes and mixes thoroughly with the exhaust gas during injection, which helps improve the conversion efficiency of the SCR system and reduce urea consumption. Because the "China VI" emission standard imposes stricter emission limits under low-temperature and low-load conditions, and the injection volume is increased, the risk of crystallization in the mixer increases. Excessive crystal formation can clog the aftertreatment channels, leading to increased back pressure in the aftertreatment system, insufficient vehicle power, and the risk of emissions exceeding regulatory limits. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a cylindrical cyclone mixer and post-processing system with low back pressure, good mixing effect, and excellent anti-crystallization performance.

[0005] To solve the above-mentioned technical problems, the first aspect of this utility model provides a cylindrical cyclone mixer, the main feature of which is that it includes a cylindrical shell and a cyclone tube disposed in the inner cavity of the cylindrical shell. The cyclone tube has an upper tube body and a lower tube body. The tube walls of the upper tube body and the lower tube body are provided with openings. A bottom perforated plate and a bottom baffle are installed at the lower opening of the lower tube body. The bottom perforated plate has several holes. The bottom perforated plate is located between the bottom baffle and the lower opening. There is an outlet gap between the bottom perforated plate and the bottom baffle, so that the gas in the cyclone tube first flows out of the cyclone tube through the holes of the bottom perforated plate and then through the outlet gap.

[0006] Preferably, a baffle is provided inside the cyclone tube.

[0007] Preferably, both the bottom perforated plate and the bottom baffle are bowl-shaped.

[0008] Preferably, the cylindrical shell has a first end and a second end opposite to the first end. A first baffle with an air inlet is installed at the first end of the cylindrical shell, and a second baffle with an air outlet is installed at the second end of the cylindrical shell. A first opening is provided in the cylindrical wall of the cylindrical shell for installing a nozzle. A guide baffle and a third baffle are provided in the inner cavity of the cylindrical shell. The third baffle has a second opening. The swirling tube passes through the second opening and is installed on the third baffle. The upper tube is located above the third baffle, and the lower tube is located below the third baffle. The upper opening of the upper tube corresponds to the first baffle. With one opening, the flow guide baffle is arranged around the upper pipe body on the third partition, forming a first cavity between the first partition, the cylindrical wall of the cylindrical shell, the flow guide baffle, and the third partition. The air inlet of the first partition is the inlet for gas to flow into the first cavity, and the opening in the pipe wall of the upper pipe body is the outlet for gas to flow out of the first cavity. A second cavity is formed between the first partition, the cylindrical wall of the cylindrical shell, the third partition, the flow guide baffle, and the second partition. The opening in the pipe wall of the lower pipe body and the air outlet are the inlets for gas to flow into the second cavity, and the air outlet of the second partition is the outlet for gas to flow out of the second cavity.

[0009] Preferably, the air inlet is located on the upper side of the first partition, such that the gas entering from the air inlet swirls around one side of the swirling tube to the outlet of the first cavity.

[0010] Preferably, the first baffle is provided with an arc-shaped protrusion extending along the axial direction of the cyclone tube. The arc-shaped protrusion is away from the cyclone tube protrusion and matches the tube wall of the cyclone tube, so that there is an arc-shaped gap between the arc-shaped protrusion and the tube wall of the cyclone tube to form a vortex.

[0011] Preferably, the air outlet includes a first air outlet and a second air outlet, wherein the opening area of ​​the first air outlet is larger than the opening area of ​​the second air outlet.

[0012] Preferably, the flow guide baffle is arc-shaped, and the flow guide baffle is provided with several arc-shaped flow guide grooves.

[0013] Preferably, the opening in the upper tube body includes a first opening and a second opening, the first opening is located above the second opening, the first opening is disposed in the upper part of the upper tube body, and a blade is disposed in part of the second opening;

[0014] The longitudinal axis of the cyclone tube is at a preset angle to the longitudinal axis of the cylindrical shell, and the preset angle is 60° to 120°.

[0015] The second aspect of this utility model provides a post-treatment system, the main feature of which is that it includes the aforementioned cylindrical swirl mixer, the first end of which is sequentially connected to a DPF and a DOC, the second end of which is connected to an SCR or an ASC, the DOC being provided with a gas inlet, the SCR or ASC being provided with a gas outlet, and the longitudinal axis of the cylindrical swirl mixer coinciding with the longitudinal axis of the post-treatment system.

[0016] The cylindrical cyclone mixing and post-treatment system of this invention, through the design of the cylindrical mixer and cyclone tube, can be applied to the China VI SCR system, with low back pressure, good mixing effect and excellent anti-crystallization performance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the post-processing system of this utility model.

[0018] Figure 2 This is a schematic diagram of the explosion of the cylindrical swirling mixing of this utility model.

[0019] Figure 3 This is a first-view schematic diagram illustrating the working principle of the cylindrical swirl mixing of this utility model.

[0020] Figure 4 This is a second-view schematic diagram illustrating the working principle of the cylindrical swirl mixing of this utility model.

[0021] Figure 5 This is a schematic diagram of the cylindrical swirl mixer of this utility model. Detailed Implementation

[0022] To make the technical problem solved by this utility model clearer, the present utility model will be further described below with reference to embodiments and accompanying drawings. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the present utility model.

[0023] like Figure 1 The diagram shown is a schematic representation of the post-treatment system of this invention. The post-treatment system includes a cylindrical swirl mixer 16. The first end of the cylindrical swirl mixer 16 is sequentially connected to a DPF 14 and a DOC 13. The second end of the cylindrical swirl mixer is connected to an SCR 18 or an ASC. The DOC 13 is connected to an intake assembly 12 to provide a gas inlet, and the SCR 18 is connected to an exhaust assembly 19 to provide a gas outlet. The longitudinal axis of the cylindrical swirl mixer 16 coincides with the longitudinal axis of the post-treatment system; that is, the post-treatment system is a straight cylindrical structure.

[0024] DPF 14, DOC 13, cylindrical swirl mixer 16, and SCR 18 can be connected via flanges, clamps 15, welding, etc., to form a straight cylindrical internal cavity. Specifically, the DPF can be designed to be detachable. DOC (Diesel Oxidation Catalyst) is a diesel engine oxidation catalyst, DPF (Diesel Particulate Filter) is a diesel particulate filter, SCR (Selective Catalytic Reduction) is a selective catalytic reduction catalyst, and ASC (Ammonia Slip Catalyst) is an ammonia oxidation catalyst. All components—DOC, DPF, SCR, and ASC—contain catalyst supports.

[0025] like Figure 1 As shown, the exhaust gas enters the aftertreatment system through the intake assembly 12, and then passes through DOC 13, DPF 14, and enters the cylindrical swirl mixer 16 in sequence. It is mixed with the reducing agent injected by the nozzle 17 inside the cylindrical swirl mixer 16, and then enters the SCR 18 for catalytic reduction reaction. Finally, the exhaust gas that meets the requirements is discharged through the exhaust assembly 19.

[0026] like Figures 2 to 5 The diagram illustrates an embodiment of the cylindrical swirl mixer of this invention, which reduces system back pressure, decreases urea crystallization, and improves the mixing efficiency of urea and waste gas, as well as the De-NOx conversion efficiency. The cylindrical swirl mixer includes a cylindrical shell 5 and a swirl tube disposed within the inner cavity of the shell 5. The swirl tube has an upper tube body 2 and a lower tube body 3. Both the upper tube body 2 and the lower tube body 3 have openings in their walls. A bottom perforated plate 10 and a bottom baffle 11 are installed at the lower opening of the lower tube body 3. The bottom perforated plate 10 has several holes and is located between the bottom baffle 11 and the lower opening. An outlet gap exists between the bottom perforated plate 10 and the bottom baffle 11, allowing the gas inside the swirl tube to first pass through the holes of the bottom perforated plate 10 and then through the outlet gap to exit the swirl tube. Both the bottom perforated plate 10 and the bottom baffle 11 are bowl-shaped. The bottom baffle 11 has no holes, allowing gas to flow out of the cyclone tube through the outlet gap. The gas passing through the bottom perforated plate can effectively remove residual urea and crystals on the bottom baffle, preventing crystal formation.

[0027] like Figure 2 As shown, a baffle plate 9 is provided inside the cyclone tube. The baffle plate is arc-shaped and has openings, which can effectively break up urea, enhance the mixing effect, and reduce the risk of urea crystallization.

[0028] like Figure 1As shown, the cylindrical housing 5 has a first end and a second end opposite to the first end. The first end of the cylindrical housing 5 is equipped with a first partition 1 having an air inlet 101, and the second end of the cylindrical housing 5 is equipped with a second partition 8 having an air outlet. The cylindrical wall of the cylindrical housing 5 is provided with a first opening 501 for installing a nozzle 17. The nozzle 17 can be installed in the first opening 501 through the mounting base 7.

[0029] The cylindrical shell 5 has a flow guide baffle 4 and a third partition 6 inside its inner cavity. The third partition 6 has a second opening, and the swirling tube passes through the second opening and is installed on the third partition 6. The third partition 6 divides the swirling tube into an upper tube 2 and a lower tube 3, with the upper tube 2 located above the third partition 6 and the lower tube 3 located below the third partition 6. The upper opening of the upper tube 2 corresponds to the first opening 501. Both the upper tube 2 and the lower tube 3 have openings in their walls, such as... Figure 5 As shown, the flow guide baffle 4 is arranged around the upper pipe body 2 on the third partition 6, forming a first cavity 1601 between the first partition 1, the cylindrical wall of the cylindrical shell 5, the flow guide baffle 4, and the third partition 6. The air inlet 101 of the first partition 1 is the inlet for gas to flow into the first cavity 1601, and the opening of the upper pipe body 2 is the outlet for gas to flow out of the first cavity 1601. Figure 2 and Figure 5 As shown, the guide baffle 4 is arc-shaped, and the guide baffle 4 is provided with several arc-shaped guide grooves 401 to facilitate the guidance of swirling gas. The interior of the swirling tube and the nozzle seat form a third cavity. The exhaust gas swirling in the first cavity enters the third cavity through the opening in the tube wall of the upper tube and mixes with the reducing agent sprayed by the nozzle in the third cavity.

[0030] like Figure 5 As shown, a second cavity 1602 is formed between the first partition 1, the cylindrical wall of the cylindrical shell 5, the third partition 6, the guide baffle 4, and the second partition 8. The opening and outlet of the lower pipe 3 serve as the inlet for gas to flow into the second cavity 1602, and the outlet of the second partition 8 serves as the outlet for gas to flow out of the second cavity 1602. The gas mixed in the third cavity enters the second cavity through the lower pipe opening and the side wall opening of the lower pipe, undergoes further mixing in the second cavity, and then flows out through the outlet.

[0031] like Figure 2 , Figure 3 and Figure 5As shown, the air inlet 101 is located on the upper side of the first partition 1, so that the gas entering from the air inlet 101 swirls around one side of the swirling tube and flows to the outlet of the first cavity 1601. Based on the side opening on the first partition, which facilitates the formation of a swirling flow, this invention does not limit the shape of the air inlet.

[0032] like Figure 2 and Figure 5 As shown, the first partition 1 is provided with an arc-shaped protrusion 102 extending along the axial direction of the cyclone tube. The arc-shaped protrusion 102 is away from the cyclone tube protrusion and matches the tube wall of the cyclone tube, so that there is an arc-shaped gap between the arc-shaped protrusion 102 and the tube wall of the cyclone tube, making the first cavity an annular cavity for forming swirl.

[0033] like Figure 2 and Figure 4 As shown, the air outlet includes a first air outlet 801 and a second air outlet 802, and the opening area of ​​the first air outlet 801 is larger than the opening area of ​​the second air outlet 802.

[0034] like Figure 2 As shown, the upper tube 2 has openings including a first opening 201 and a second opening. The first opening 201 is located above the second opening and is disposed on the upper part of the upper tube 2. A blade is disposed in part of the second opening. The blade can face inward or outward.

[0035] The longitudinal axis of the cyclone tube forms a predetermined angle with the longitudinal axis of the cylindrical shell, the predetermined angle being 60° to 120°, preferably around 90°. The cyclone tube can be a circular tube, an elliptical tube, or other similar shapes.

[0036] The cylindrical cyclone mixer and post-treatment system of this invention, through the design of the cylindrical mixer and cyclone tube, can be applied to the China VI SCR system, with low back pressure, good mixing effect and excellent anti-crystallization performance.

[0037] The above descriptions are specific embodiments of this utility model and do not constitute a limitation on the scope of protection of this utility model. Any modifications and variations made to the technical concept of this utility model should be included within the scope of protection of this utility model.

Claims

1. A cylindrical cyclone mixer, characterized in that, The device includes a cylindrical shell and a cyclone tube disposed within the inner cavity of the cylindrical shell. The cyclone tube has an upper tube body and a lower tube body. Both the upper and lower tube bodies have openings in their walls. A bottom orifice plate and a bottom baffle are installed at the lower opening of the lower tube body. The bottom orifice plate has several holes and is located between the bottom baffle and the lower opening. An outlet gap exists between the bottom orifice plate and the bottom baffle, allowing the gas in the cyclone tube to first flow through the holes in the bottom orifice plate and then through the outlet gap to exit the cyclone tube.

2. The cylindrical cyclone mixer according to claim 1, characterized in that, A baffle is installed inside the cyclone tube.

3. The cylindrical cyclone mixer according to claim 1, characterized in that, Both the bottom perforated plate and the bottom baffle are bowl-shaped.

4. The cylindrical cyclone mixer according to any one of claims 1 to 3, characterized in that, The cylindrical shell has a first end and a second end opposite to the first end. A first baffle with an air inlet is installed at the first end of the cylindrical shell, and a second baffle with an air outlet is installed at the second end of the cylindrical shell. A first opening is provided in the cylindrical wall of the cylindrical shell for installing a nozzle. A flow guide baffle and a third baffle are provided in the inner cavity of the cylindrical shell. The third baffle has a second opening. The swirling tube passes through the second opening and is installed on the third baffle. The upper tube is located above the third baffle, and the lower tube is located below the third baffle. The upper opening of the upper tube corresponds to the first opening. The flow guide baffle is arranged around the upper pipe body on the third partition, forming a first cavity between the first partition, the cylindrical wall of the cylindrical shell, the flow guide baffle, and the third partition. The air inlet of the first partition is the inlet for gas to flow into the first cavity, and the opening in the pipe wall of the upper pipe body is the outlet for gas to flow out of the first cavity. A second cavity is formed between the first partition, the cylindrical wall of the cylindrical shell, the third partition, the flow guide baffle, and the second partition. The opening in the pipe wall of the lower pipe body and the air outlet interval are the inlet for gas to flow into the second cavity, and the air outlet of the second partition is the outlet for gas to flow out of the second cavity.

5. The cylindrical cyclone mixer according to claim 4, characterized in that, The air inlet is located on the upper side of the first partition, so that the gas entering from the air inlet swirls around one side of the swirling tube to the outlet of the first cavity.

6. The cylindrical cyclone mixer according to claim 4, characterized in that, The first baffle plate is provided with an arc-shaped protrusion extending along the axial direction of the cyclone tube. The arc-shaped protrusion is away from the cyclone tube protrusion and matches the tube wall of the cyclone tube, so that there is an arc-shaped gap between the arc-shaped protrusion and the tube wall of the cyclone tube to form a cyclone.

7. The cylindrical cyclone mixer according to claim 4, characterized in that, The air outlet includes a first air outlet and a second air outlet, wherein the opening area of ​​the first air outlet is larger than the opening area of ​​the second air outlet.

8. The cylindrical cyclone mixer according to claim 4, characterized in that, The flow guide baffle is arc-shaped and has several arc-shaped flow guide grooves.

9. The cylindrical cyclone mixer according to claim 1, characterized in that, The opening in the upper tube body includes a first opening and a second opening. The first opening is located above the second opening and is disposed on the upper part of the upper tube body. A blade is disposed in part of the second opening. The longitudinal axis of the cyclone tube is at a preset angle to the longitudinal axis of the cylindrical shell, and the preset angle is 60° to 120°.

10. A post-processing system, characterized in that, The system includes a cylindrical cyclone mixer as described in any one of claims 1 to 9, wherein the first end of the cylindrical cyclone mixer is connected in sequence to a DPF and a DOC, the second end of the cylindrical cyclone mixer is connected to an SCR or an ASC, the DOC is provided with a gas inlet, the SCR or ASC is provided with a gas outlet, and the longitudinal axis of the cylindrical cyclone mixer coincides with the longitudinal axis of the post-treatment system.

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