Anti-wear venturi reactor with high-efficiency gas-solid mixing

Abstract

An anti-wear venturi reactor with high-efficiency gas-solid mixing. A feeding section (1), a Venturi section (2) and a straight cylinder section (3) are sequentially arranged in the flow direction of flue gas, wherein a material chute (4) is disposed on one side of the feeding section (1); the Venturi section (2) comprises a converging section (21), a straight tube (22) and a diverging section (23), the converging section (21) being connected to the feeding section (1), and the diverging section (23) being connected to the straight cylinder section (3); a first spiral track (51) is arranged on the inner wall of the feeding section (1), and at least part of the first spiral track (51) is lower than the plane where the material chute (4) is located; and a second spiral track (52) is arranged on the inner wall of the straight tube of the Venturi section (2).

Description

A gas-solid high-mixing anti-wear Venturi reactor

[0001] Cross-references to related applications

[0002] This application claims priority to and is based on Chinese Patent Application No. 2024109359051, filed on July 12, 2024, with the invention title "A Gas-Solid High-Mixing Anti-Wear Venturi Reactor", the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a gas-solid mixing reactor, and more particularly to a gas-solid high-mixing Venturi reactor. Background Technology

[0004] Circulating fluidized bed reactors involve two types of particle circulation: internal and external circulation. External circulation refers to particles returning from the bed outlet to the bottom of the bed via a circulating chute to continue participating in the reaction. Internal circulation, on the other hand, involves particles rising from the center of the bed and sliding down the edges. Correspondingly, external circulation, with material returning from only one side of the bed outlet, suffers from insufficient time for diffusion due to its rapid fluidization. This inadequate mixing limits the reactor's efficiency, and the concentration of particles on the feed side leads to severe wear on that side of the reactor wall. Internal circulation, however, causes wear on the reactor wall during the reciprocating motion of the particles.

[0005] Current solutions to the gas-solid mixing problem involve installing internal swirling components or introducing spray guns to blow particles. Patent application number 201310094812.2 discloses a composite airflow generator installed in the feed section. This device forms a straight-swirling-straight airflow field, achieving premixing and homogenization of particles and flue gas through flue gas swirling and turbulence. However, the device has densely packed guide vanes, providing landing points for ash in the bottom feed section of the tower. Ash adheres easily to the vane walls, leading to ash accumulation and blockage of the flow channels. Under the impact of high-speed flue gas, the structural framework of the swirling components is prone to deformation, and the vanes are also at risk of falling off. The device is complex to manufacture and difficult to install, making it difficult to promote and apply in the field. Current solutions to the wall wear problem mainly use wear-resistant beams. However, the wear risk at the junction of the Venturi section and the straight section comes not only from the erosion of particles sliding off the peripheral wall but also from the turbulent scouring of scattered particles in the Venturi section. Simply using wear-resistant beams to reduce the concentration and velocity of the wall-attached flow is insufficient to prevent wear from the turbulent scouring of scattered particles. Summary of the Invention

[0006] This invention provides a gas-solid high-mixing anti-wear Venturi reactor, which achieves high mixing and homogenization of flue gas and particles, while avoiding the problem of ash accumulation and swelling in the reactor, which leads to agglomeration and blockage of the flow channel. At the same time, it can prevent particles from directly scouring the tube wall and improve the anti-wear performance.

[0007] To address the aforementioned problems, this invention provides a gas-solid high-mixing anti-wear Venturi reactor, comprising a feed section, a Venturi section, and a straight section arranged sequentially along the flue gas flow direction, with a material chute located on one side of the feed section. The Venturi section includes a constricted end, a straight tube, and a flared end; the constricted end is connected to the feed section, and the flared end is connected to the straight section. A first helical track is provided on the inner wall of the feed section, with at least a portion of the first helical track being lower than the plane where the material chute is located. A second helical track is provided on the inner wall of the straight tube of the Venturi section.

[0008] In some embodiments, the first spiral track is convex, protruding toward the center of the feed section.

[0009] In some embodiments, the width of the first helical track protrusion is greater than or equal to 1 / 10 of the diameter of the feed section.

[0010] In some embodiments, the second helical track is convex, protruding toward the center of the straight tube.

[0011] In some embodiments, the second helical track is concave towards the straight pipe wall.

[0012] In some embodiments, the second spiral track is divided into a first part and a second part, the first part being close to the constriction and the second part being close to the flare; the first part is convex in shape and protrudes toward the center of the straight pipe, and the second part is concave in shape and recessed toward the wall of the straight pipe.

[0013] In some embodiments, the cross-sections of the first and second helical tracks are circular, triangular, rectangular, or trapezoidal.

[0014] In some embodiments, the entire first spiral track is below the plane containing the material chute.

[0015] In some embodiments, the junction of the straight section and the venturi section is covered with an arc-shaped anti-wear ring plate.

[0016] In some embodiments, the second helical track and the arc-shaped anti-wear ring plate are made of wear-resistant material.

[0017] Compared with the prior art, the beneficial effects of this invention are as follows:

[0018] 1. This invention uses a first spiral track on the inner wall of the feed section below the material chute to turbulently form swirling flue gas, so that the particles after feeding are mixed by being entrained by the swirling flue gas; a second spiral track is set on the inner wall of the straight cylinder in the Venturi section to further enhance the swirling flue gas, achieving high mixing of flue gas and particles while avoiding ash accumulation and agglomeration in the reactor, thus preventing blockage of the flow channel. At the same time, the steps formed by the spiral track can prevent particles from directly scouring the wall surface and also form abrasion protection for the wall surface.

[0019] This invention prevents wear on the wall surface caused by the turbulent scouring of particles accelerated in the Venturi section by setting an arc-shaped anti-wear ring plate at the junction of the straight pipe section and the Venturi section. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the Venturi reactor of the present invention;

[0021] Figure 2 is a schematic diagram showing the positions of the first spiral track, the second spiral track, and the arc-shaped annular template of the present invention.

[0022] Figure 3 is a schematic diagram of the cross-section of the first spiral track in the feeding section;

[0023] Figure 4 is a schematic diagram of the cross-section of the convex second spiral track in the Venturi section;

[0024] Figure 5 is a schematic diagram of the cross-section of the concave second spiral track in the Venturi section;

[0025] Figure 6 is a schematic diagram of the cross-section of the second spiral track with a convex lower section and a concave upper section in the Venturi section;

[0026] Figure 7 is a schematic diagram of the cross-sectional shape types of spiral tracks;

[0027] Figure 8 is a schematic diagram of the arc-shaped anti-wear ring plate.

[0028] Attached reference numerals: 1. Feeding section; 2. Venturi section; 3. Straight cylinder section; 4. Material chute; 5. Double-stage spiral track; 6. Arc-shaped anti-wear ring plate; 21. Narrowing; 22. Straight pipe; 23. Flaring; 51. First spiral track; 52. Second spiral track. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0032] In circulating fluidized bed reactors, the circulating material is fed from one side. Due to its rapid fluidization operation, the material entering from one side lacks sufficient time for adequate diffusion before being transported to the bed to participate in circulating fluidization and chemical reactions. Insufficient particle mixing limits the reactor's efficiency, and the concentration of particles on the feed side also causes severe wear on that side of the reactor wall. Current inventions disclose swirling and turbulence-inducing components, which are complex in structure and difficult to manufacture and install. The multi-blade design provides landing points for ash, and the blade walls are prone to ash adhesion and swelling, leading to agglomeration and blockage of the flow channels.

[0033] Referring to Figures 1-8, to address the aforementioned problems, this embodiment provides a gas-solid high-mixing anti-wear Venturi reactor. Along the flue gas flow direction, a feed section 1, a Venturi section 2, and a straight section 3 are sequentially arranged, with a material chute 4 located on one side of the feed section 1. The Venturi section 2 includes a constriction 21, a straight pipe 22, and a flared end 23. The constriction 21 is connected to the feed section 1, and the flared end 23 is connected to the straight section 3. A double-stage helical track 5 is also provided within the reactor. Specifically, a first helical track 51 is provided on the inner wall of the feed section 1, with its highest point located below the horizontal plane where the material chute 4 is located. A second helical track 52 is provided on the inner wall of the straight pipe 22 of the Venturi section 2.

[0034] The flue gas to be reacted enters through the feed section and forms a swirling flow under the guidance of the first spiral track 51. The absorbent particles that have accumulated at the outlet of the material chute 4 are initially diffused under the rising swirling flue gas. After passing through the Venturi section 2, the swirling flue gas is further accelerated and converted into jet flue gas. At the same time, under the guidance of the second spiral track 52, a swirling jet flue gas is formed, and the absorbent particles are also fully mixed in this area. This achieves high mixing of the gas and solid phases of the flue gas and the feed particles. Meanwhile, the spiral track adheres to the wall surface and does not generate new ash adhesion points, preventing channel blockage. The structure is also simple and easy to manufacture and install.

[0035] After passing through the straight pipe 22 in the Venturi section, the material particles swirl upwards in the central region of the straight section 3 and then slide down the surrounding walls, causing abrasive erosion of the walls from top to bottom. Simultaneously, the flue gas in the Venturi section 2 is accelerated, and the turbulent flow of particles erodes the walls from bottom to top. The junction of the straight section 3 and the Venturi section 2 receives the most particle impact. Therefore, in this embodiment, an arc-shaped anti-wear ring plate 6 is placed at the junction of the straight section 3 and the Venturi section 2 to buffer and protect the landing particles. The arc-shaped anti-wear ring plate 6 is made of NM series, Mn series, or chromium carbide series wear-resistant metallic materials.

[0036] In this embodiment, the second spiral track 52 is also made of wear-resistant material. Therefore, the second spiral track 52 forms a swirling airflow to achieve high mixing of particles and flue gas. On the other hand, the steps formed by the second spiral track 52 on the pipe wall can prevent particles from directly scouring the pipe wall, thus forming wear-resistant protection.

[0037] As shown in Figure 3, since the feed section 1 needs to pre-turbulent the flue gas into an upward swirling state and further accelerate the flue gas, so that the material particles entering the material chute 4 can be fully mixed in the swirling flue gas, in this embodiment, the first spiral track 51 is convex, protruding towards the center of the feed section. Meanwhile, in order to ensure that the boundary of the swirling flow is within the range of the material particles entering the material chute 4, the width of the convex part of the first spiral track 51 is greater than or equal to 1 / 10 of the diameter of the feed section 1. If it is less than 1 / 10 of the diameter of the feed section 1, the resulting swirling airflow will be too small to ensure that all material particles flow upwards.

[0038] As shown in Figure 4, the flue gas in the Venturi section 2 is accelerated by the constriction 21 and then enters the straight pipe 22 and diffuses through the flare 23. In this embodiment, the second spiral track 52 on the inner wall of the straight pipe 22 is convex and protrudes towards the straight pipe wall, thereby receiving the flue gas accelerated by the constriction 21 and further accelerating the flue gas.

[0039] As shown in Figure 5, as a simple alternative to this embodiment, the second spiral track 52 can also be concave towards the straight pipe wall, so that the flue gas is pre-diffused and connected to the flared opening 23 in the straight pipe 22.

[0040] As shown in Figure 6, in order to simultaneously satisfy the requirements of receiving the constriction 21 and connecting the flare 23, as a simple alternative in this embodiment, the second spiral track 51 is divided into a first part and a second part. The first part is close to the constriction 21, and the second part is close to the flare 23. The first part is convex, protruding towards the center of the straight pipe, and the second part is concave, recessed towards the wall of the straight pipe. The first part near the constriction 21 is convex to receive the constriction 21 and further accelerate the flue gas, while the second part near the flare 23 is concave to pre-diffuse the flue gas and connect it to the flare 23.

[0041] In this embodiment, the cross-section of the first spiral track 51 and the second spiral track 52 can be in the shape of a circular arc, triangle, rectangle, trapezoid, or other geometric shapes that can form a concave-convex structure.

[0042] The gas-solid high-mixing anti-wear Venturi reactor of this embodiment features a double-stage helical track structure in the feed section 1 and the Venturi section 2. The first helical structure in the feed section 1 swirls the flue gas before feeding (51). After feeding, the particles mix with the flue gas and swirl upwards. The second helical structure in the Venturi section 2 further mixes the gas and solids, achieving high gas-solid mixing. The helical tracks adhere to the wall surface without creating new ash adhesion points, preventing channel blockage. The structure is also simple and easy to manufacture and install. Simultaneously, the arc-shaped anti-wear ring plate 6 at the junction of the second helical track 52 of the straight tube 22 in the Venturi section and the junction of the Venturi section 2 and the straight tube section 3 protects high-risk wear areas.

[0043] The above description is merely a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention by those skilled in the art within the scope of the technology disclosed in the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention. Industrial applicability

[0044] This invention provides a gas-solid high-mixing anti-wear Venturi reactor, comprising a feed section, a Venturi section, and a straight section arranged sequentially along the flue gas flow direction, with a material chute located on one side of the feed section. The Venturi section includes a constricted end, a straight tube, and a flared end; the constricted end is connected to the feed section, and the flared end is connected to the straight section. The invention is characterized by a first helical track arranged on the inner wall of the feed section, at least a portion of which is lower than the plane of the material chute; and a second helical track arranged on the inner wall of the straight tube of the Venturi section. This design has industrial applicability.

Claims

1. A gas-solid high-mixing, wear-resistant Venturi reactor, comprising a feed section, a Venturi section, and a straight section arranged sequentially along the flue gas flow direction, with a material chute located on one side of the feed section; the Venturi section includes a constricted end, a straight tube, and a flared end, the constricted end being connected to the feed section, and the flared end being connected to the straight section, characterized in that, A first spiral track is provided on the inner wall of the feeding section, and at least a portion of the first spiral track is lower than the plane where the material chute is located; a second spiral track is provided on the inner wall of the straight pipe of the Venturi section.

2. The gas-solid high-mixing anti-wear Venturi reactor according to claim 1, characterized in that, The first spiral track has a convex shape that protrudes towards the center of the feed section.

3. The gas-solid high-mixing anti-wear Venturi reactor according to claim 2, characterized in that, The width of the first spiral track protrusion is greater than or equal to 1 / 10 of the diameter of the feed section.

4. The gas-solid high-mixing anti-wear Venturi reactor according to claim 1, characterized in that, The second spiral track is convex, protruding towards the center of the straight tube.

5. The gas-solid high-mixing anti-wear Venturi reactor according to claim 1, characterized in that, The second spiral track is concave in shape and recessed towards the straight pipe wall.

6. The gas-solid high-mixing anti-wear Venturi reactor according to claim 1, characterized in that, The second spiral track is divided into a first part and a second part. The first part is close to the constriction and the second part is close to the flare. The first part is convex and protrudes towards the center of the straight pipe, and the second part is concave and recessed towards the wall of the straight pipe.

7. The gas-solid high-mixing anti-wear Venturi reactor according to claim 1, characterized in that, The cross-sections of the first and second helical tracks are circular, triangular, rectangular, or trapezoidal.

8. The gas-solid high-mixing anti-wear Venturi reactor according to claim 1, characterized in that, The entire first spiral track is below the plane where the material chute is located.

9. The gas-solid high-mixing anti-wear Venturi reactor according to claim 1, characterized in that, The junction between the straight section and the venturi section is covered with an arc-shaped anti-wear ring plate.

10. The gas-solid high-mixing anti-wear Venturi reactor according to claim 9, characterized in that, The second spiral track and the arc-shaped anti-wear ring plate are made of wear-resistant materials.

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