Smoke separation device and separation method based on vortex street disturbance and baffle inertia collision

Abstract

The application discloses a smoke dust separation device based on vortex street disturbance and baffle inertia collision combination, which comprises a main flow elbow pipe, a vortex street generation cylinder is arranged in the main flow elbow pipe, an ash bucket is arranged at the bottom of the main flow elbow pipe, a flow guide baffle is arranged in the main flow elbow pipe and the ash bucket in a penetrating mode, and an ash discharging bin is arranged at the lower part of the ash bucket. The application further discloses a smoke dust separation method based on vortex street disturbance and baffle inertia collision combination, and solves the problem of low dust removal efficiency of the existing dust removal device.

Description

Technical Field

[0001] This invention belongs to the field of primary coarse dust collection technology in converters, and relates to a dust separation device based on vortex shedding and baffle inertial collision. This invention also relates to a dust separation method based on vortex shedding and baffle inertial collision. Background Technology

[0002] Converter steelmaking, as an important steelmaking method, is the main steelmaking method in my country, accounting for more than 90% of the country's total steel production. Existing converter flue gas waste heat recovery systems suffer from problems such as increased resistance and high maintenance costs. This is mainly because converter flue gas contains a large amount of large-diameter dust, which easily accumulates and wears inside the primary dust separator, leading to increased system resistance and easy wear of the equipment, resulting in high maintenance costs. Therefore, it is necessary to optimize the equipment for resistance reduction, efficiency improvement, and wear resistance.

[0003] Currently, the particle size distribution of primary dust in steelmaking converters ranges from 10 to 200 μm, with a median particle size of approximately 50 μm. The dust particles are generally quite large, and the commonly used cyclone dust collectors and inertial dust collectors in converter coarse dust removal systems have certain limitations. Cyclone dust collectors are suitable for coarse dust particles larger than 10 μm and have high dust removal efficiency, but they cannot form a plunger flow, easily creating a stagnant zone for explosive flue gas, posing an explosion hazard. Furthermore, their system resistance is high, with equipment losses exceeding 1000 Pa to 1500 Pa, resulting in high energy consumption and poor economic efficiency. Inertial dust collectors are suitable for coarse dust particles larger than 20 to 30 μm, have a simple structure, and low system resistance, but their dust removal efficiency is lower than that of cyclone dust collectors.

[0004] The coarse dust separators in existing converter dry dust removal systems often employ separators based on the principle of inertial separation, which are characterized by low resistance and convenient maintenance, but have relatively low dust separation efficiency. Therefore, a dust separation device based on the combination of vortex shedding and baffle inertial collision is proposed. This device can improve dust separation efficiency while ensuring low system resistance, thereby promoting the overall low-carbon and energy-saving of the converter dry dust removal system. Summary of the Invention

[0005] The purpose of this invention is to provide a dust separation device based on the combination of vortex shedding and baffle inertial collision, which solves the problem of low dust removal efficiency in existing dust removal devices.

[0006] Another objective of this invention is to provide a method for separating smoke and dust based on vortex shedding and inertial collision with baffles.

[0007] The first technical solution adopted in this invention is a dust separation device based on the combination of vortex street turbulence and baffle inertial collision, including a main bend, a vortex street generating cylinder is provided inside the main bend, an ash hopper is provided at the bottom of the main bend, a guide baffle is provided through the main bend and the ash hopper, and an ash discharge bin is provided at the bottom of the ash hopper.

[0008] The first technical solution of this invention is further characterized by:

[0009] The ash hopper has an inverted frustum-shaped structure.

[0010] The inner wall of the ash hopper is a dust collection wall, which is a heat-insulating and fire-resistant lining.

[0011] The surface of the cylinder generating the vortex street is provided with triangular ribs.

[0012] The triangular ribs are spirally and equidistantly distributed on the surface of each vortex street generation cylinder.

[0013] Several multi-layered baffles of the same size are provided on one side of the flow guide baffle, and the multi-layered baffles are located inside the ash hopper.

[0014] Each multi-layered baffle has a curved downward bend at its lower tail.

[0015] The second technical solution adopted in this invention is a dust separation method based on the combination of vortex shedding and baffle inertial collision, which specifically includes the following process: Dust-laden flue gas enters from the main bend pipe and first passes through the cylindrical vortex generator inside the main bend pipe to undergo boundary layer separation, causing the dust-laden flue gas to collide with the guide baffle and the inner wall of the main bend pipe respectively. The guide baffle guides the dust-laden flue gas to flow in the direction of the ash discharge bin. The dust-laden flue gas flows to one side of the guide baffle and collides with multiple layers of baffles. Dust particles that have not been separated from the flue gas after passing through the cylindrical vortex generator are separated by inertial collision.

[0016] The beneficial effects of this invention are as follows: 1) Enhance particle separation effect by using cylindrical vortex street turbulence separation and guiding particle collision and agglomeration.

[0017] 2) Compared with the separator's internal baffle collision, the addition of cylindrical vortex street turbulence improves separation efficiency by reducing the contact area with dust-laden flue gas. Furthermore, by utilizing the boundary layer separation principle, the system resistance is relatively low, resulting in significant energy savings.

[0018] 3) Each vortex shear device has right-angled triangular ribs arranged in a spiral pattern on its surface to reduce airflow resistance.

[0019] 4) After the vortex shear device, a multi-stage baffle structure is installed to reduce secondary dust generation in the separator. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the dust separation device based on vortex shear and baffle inertial collision of the present invention. Figure 2This is a partial schematic diagram of the triangular ribs on the surface of the cylindrical vortex generator inside the dust separation device based on vortex street turbulence and baffle inertial collision according to the present invention. Figure 3 This is a partial structural diagram of the multi-layer baffle arrangement inside the dust separation device based on vortex shear and baffle inertial collision of the present invention. Figure 4 This is a comparative analysis of the separation efficiency and resistance of the present invention and the method without any optimization device for separating smoke particles; Figure 5(a) and Figure 5(b) are the flue gas velocity cloud diagrams of the ZX section of the flue gas separation device without any internal optimization device and the flue gas separation device of the present invention based on vortex turbulence and baffle inertial collision; wherein, Figure 5(a) is the flue gas velocity cloud diagram of the ZX section without any optimization device, and Figure 5(b) is the flue gas velocity cloud diagram of the ZX section of the present invention. Figure 6 This is a cloud map showing the internal pressure distribution of the dust separation device based on vortex shear and baffle inertial collision according to the present invention.

[0021] In the figure, 1. Mainstream bend, 2. Vortex generator cylinder, 3. Guide baffle, 4. Ash hopper, 5. Multi-layer baffle, 6. Ash discharge bin, 7. Dust collection wall, 8. Triangular rib, 9. Arc-shaped downward bend. Detailed Implementation

[0022] The following detailed description is provided in conjunction with specific implementation methods.

[0023] This invention relates to a dust separation device based on a combination of vortex shedding and baffle inertial collision, such as... Figure 1 As shown, the device includes a main flow bend 1 with left inlet and top outlet. Inside the main flow bend 1, cylindrical structures 2 that generate vortex streets are installed in close proximity to the inner walls (the dust-laden flue gas will generate vortex streets around these cylinders when it passes through them). At the bottom of the main flow bend 1, there is an inverted frustum-shaped ash hopper 4. To ensure that the dust-laden flue gas is divided within the ash hopper 2, a guide baffle 3 is installed inside the device. The guide baffle 3 is installed in both the main flow bend 1 and the ash hopper 4. To further separate the dust particles, several multi-layered baffles 5 of the same size are installed on the right side of the guide baffle 3, connecting the inner walls of the ash hopper. Dust collection walls 7 are installed on both sides of the ash hopper 4 to capture secondary dust and small-diameter particles. At the bottom of the ash hopper 4, there is an ash discharge bin 6 for collecting the dust particles separated from the flue gas. The ash discharge port at the bottom of the ash discharge bin 6 is opened periodically to discharge the dust particles.

[0024] The main bend 1 is equipped with a dust-laden flue gas inlet and outlet. The ash hopper 4 is connected to the bottom of the main bend 1 and has an overall inverted frustum-shaped structure. The ash discharge bin 6 is connected to the bottom of the ash hopper 4 and has an overall inverted trapezoidal structure. A vortex generator cylinder 2 is installed inside the main bend 1 to divert the dust-laden flue gas before it enters the ash hopper 4. A guide baffle 3 is installed inside the main bend 1 and the ash hopper 4 to divert the main dust-laden flue gas.

[0025] Inside the ash hopper 4, four vortex-generating cylinders 2 are arranged on the left side of the guide baffle 3, three vortex-generating cylinders 2 are arranged on the right side, and seven multi-layered baffles 5 of the same size arranged from top to bottom penetrate the front and rear walls of the ash hopper 4. The number of vortex-generating cylinders 2 and multi-layered baffles 5 can be selected according to actual needs.

[0026] The surface of the vortex generator cylinder 2 is provided with drag-reducing triangular ribs 8. These triangular ribs 8 are spirally and equidistantly distributed on the surface of each vortex generator cylinder 2. The number of triangular ribs 8 can be appropriately adjusted according to the size of the vortex generator cylinder. The minimum acute angle of a single triangle is 30°. See [link to relevant documentation]. Figure 2 As shown. Figure 2 In the diagram, h1 and h2 represent the spacing between adjacent triangular ribs 8. The spacing between adjacent triangular ribs 8 is equal, i.e., h1 = h2.

[0027] Each multi-layer baffle 5 has a downward-curving arc 9 at its right tail end. The downward-curving arc 9 is used to increase the contact surface between the dust particles and each baffle in the multi-layer baffle 5, thereby increasing the collision. The uppermost baffle in the multi-layer baffle 5 has a different angle from the other baffles. This angle is different from the other baffles and is close to the guide baffle 3, which can further divert the dust-laden flue gas and increase the collision effect between the dust-laden flue gas and the guide baffle 3.

[0028] Except for the topmost baffle, all other baffles in the multi-layer baffle 5 form an angle of 60° with the horizontal plane, except for the topmost baffle, which forms an angle of 120° with the horizontal plane. (See...) Figure 3 As shown. A dust hopper 4 is installed below the flow bend pipe 1, and a dust discharge bin 6 is installed at the bottom of the dust hopper.

[0029] The dust collection wall 7 is a heat-insulating and fire-resistant lining, which is attached to the inner walls of the left and right sides of the ash hopper 4, with a thickness ranging from 100 to 150 mm.

[0030] The guide baffle 3 is installed inside the dust separation device, with a length of 4500mm and a thickness of 20mm. It runs through the inner walls of the dust separation device.

[0031] Several vortex generator cylinders 2, which are connected to the dust separation device, are arranged on the right side of the guide baffle 3. One cylinder is arranged from top to bottom in the main flow bend 1, four cylinders are arranged from top to bottom on the left side of the guide baffle 3 in the ash hopper, and three cylinders are arranged from bottom to top on the right side of the guide baffle 3. This guides the dust-laden flue gas to collide with the guide baffle 3 and the side wall of the ash hopper, and at the same time, it guides the dust-laden flue gas to flow to the right side of the guide baffle.

[0032] The adjacent triangular fins of the vortex street generator cylinder 2 are of the same size and thickness, and are equidistant from each other, with a spacing ranging from 70 to 980 mm. Their function is to achieve a significant reduction in drag when the minimum acute angle of the triangular fins is 30°. By incorporating triangular fins into the vortex street turbulence device, the direct impact between the fluid and the device is reduced, thereby lowering the drag generated by fluid collisions.

[0033] The baffles, with an inclination angle opposite to the other baffles, serve to increase the collision between the dust-laden flue gas about to exit the separator and the baffles, causing the dust particles to separate again, while simultaneously homogenizing the flow field of the flue gas inside the separator. Each baffle in the multi-layer baffle 5 has a small arc-shaped bend at its right end, with a bend length ranging from 100 to 120 mm. Its function is to increase the contact area between the dust-laden flue gas and each baffle, and to a certain extent, to change the direction and velocity of the dust-laden flue gas again, thereby improving the dust separation efficiency.

[0034] The separation method of the dust separation device based on the combination of vortex shear and baffle inertial collision is as follows: After the dust-laden flue gas enters the device from the inlet of the main flow bend 1, it first passes through the cylindrical vortex generator 2 set inside the main flow bend 1, where boundary layer separation occurs on its surface. This causes the dust-laden flue gas to collide with the guide baffle 3 and the inner wall of the main flow bend 1 respectively. Some dust particles are separated due to inertia. At the same time, the guide baffle 3 guides the dust-laden flue gas to flow towards the ash discharge bin 6. The dust-laden flue gas first passes through the cylindrical vortex generator 2 on the left side of the guide baffle 3 in sequence. After passing through each cylindrical vortex generator, the dust-laden flue gas... When the generator 2 is activated, a vortex street phenomenon will occur in the wake of the cylindrical vortex generator 2. This vortex street phenomenon will enhance the collision between the dust particles and the guide baffle 3 and the side wall of the ash hopper 4. Some dust particles will be separated from the flue gas due to inertial collision. At the same time, the small vortex formed will promote the agglomeration of small-diameter particles. The particle group that has agglomerated to a certain extent will fall into the ash discharge bin 6 under the action of gravity. The dust-laden flue gas flows to the right side of the guide baffle 3 and continues to collide with the multi-layer baffle 5. Dust particles that have not been separated from the flue gas after passing through the cylindrical vortex generator 2 will be separated by inertial collision.

[0035] Example 1 The dust separation device based on the combination of vortex street turbulence and baffle inertial collision includes a main flow bend 1, a vortex street generating cylinder 2 inside the main flow bend 1, an ash hopper 4 at the bottom of the main flow bend 1, a flow guide baffle 3 running through the main flow bend 1 and the ash hopper 4, and an ash discharge bin 6 at the bottom of the ash hopper 4. The ash hopper 4 has an inverted frustum-shaped structure. The inner wall of the ash hopper 4 is a dust collection wall 7, which is lined with a heat-insulating and fire-resistant lining.

[0036] Example 2 A dust separation device based on the combination of vortex street turbulence and baffle inertial collision includes: a main flow bend 1 with a flue gas inlet and outlet; an ash hopper 4 located at the bottom of two lower bends, directly connected to the main flow bend; an ash discharge bin 6 located at the bottom of the ash hopper and directly connected to the bottom of the ash hopper; a flow guide baffle 3 located inside the separation device, penetrating the main flow bend and the ash hopper, extending to the lower middle part of the ash hopper; a vortex street generating cylinder 2 located inside the separation device, with several cylinders arranged penetrating the main flow bend and the left side of the flow guide baffle in the ash hopper; a multi-layer baffle 5 located inside the ash hopper, vertically arranged at equal intervals on the right side of the flow guide baffle, in the right half of the ash hopper; and a dust collection wall 7, with a heat-insulating and refractory lining serving as the dust collection wall, located on the left and right side walls of the ash hopper.

[0037] Example 3 A dust separation device based on the combination of vortex street turbulence and baffle inertial collision includes a main flow bend 1, a vortex street generating cylinder 2 inside the main flow bend 1, an ash hopper 4 at the bottom of the main flow bend 1, a flow guide baffle 3 running through the main flow bend 1 and the ash hopper 4, and an ash discharge bin 6 at the bottom of the ash hopper 4. The ash hopper 4 has an inverted frustum-shaped structure. The inner wall of the ash hopper 4 is a dust collection wall 7, which is lined with heat-insulating and fire-resistant material. The surface of the vortex street generating cylinder 2 is provided with triangular ribs 8. The triangular ribs 8 are spirally and equidistantly distributed on the surface of each vortex street generating cylinder 2. Several multi-layer baffles 5 of the same size are provided on one side of the flow guide baffle 3, and the multi-layer baffles 5 are located inside the ash hopper 4. Each multi-layer baffle 5 has an arc-shaped downward bend 9 at its lower tail.

[0038] Example 4 The dust separation method based on the combination of vortex shear and baffle inertial collision includes the following process: Dust-laden flue gas enters from the main flow bend 1 and first passes through the cylindrical vortex generator 2 inside the main flow bend 1 to undergo boundary layer separation, causing the dust-laden flue gas to collide with the guide baffle 3 and the inner wall of the main flow bend 1 respectively. The guide baffle 3 guides the dust-laden flue gas to flow towards the ash discharge bin 6. The dust-laden flue gas flows to one side of the guide baffle 3 and collides with the multi-layer baffle 5. Dust particles that have not been separated from the flue gas after passing through the cylindrical vortex generator 2 are separated by inertial collision.

[0039] Example 5 To demonstrate that the dust separation device based on the combination of vortex shear and baffle inertial collision significantly improves the separation efficiency of dust particles, this embodiment uses numerical simulation to compare and analyze the separation effect of dust particles with and without the optimized device. The boundary conditions are shown in Table 1.

[0040] Table 1. Boundary Condition Parameters for Numerical Simulation

[0041] Figure 5 shows the flow velocity distribution cloud map of the dust separation device of the present invention and the dust separation device without any optimization device. As shown in Figure 5(a), in the dust separation device without any optimization device, the dust-laden flue gas enters from the flue gas inlet and hardly enters the lower ash hopper. Most of the dust-laden flue gas flows directly out from the outlet of the main flue gas bend. The separation of dust particles relies solely on the inertial force experienced by the dust-laden flue gas flowing in the main flue gas bend to detach from the main flue gas. As shown in Figure 5(b), under the action of the optimization device of the present invention, the guide baffle forces the dust-laden flue gas to flow into the ash hopper. The dust-laden flue gas passes through the vortex generation cylinder, where boundary layer separation occurs. This increases the collision between the dust-laden flue gas and the baffle and the side wall of the ash hopper, making it easier for dust particles to separate from the flue gas during the collision process, which is basically consistent with the expected flow direction. At the same time, small vortices are formed on the back side of each vortex generator. These vortices can cause small-diameter dust particles to agglomerate into large-diameter particles, which eventually fall into the ash discharge bin.

[0042] Figure 6 This displays a pressure distribution cloud map inside the optimized device according to the present invention. Figure 6 It can be seen that the resistance of the dust-laden flue gas flowing inside the separator is less than 400 Pa, which is relatively small. The resistance when the dust-laden flue gas collides with the left cylinder is smaller than the resistance when it collides with the right baffle. When the dust-laden flue gas flows from the left cylinder through the middle guide plate to the right baffle, the resistance increases at the guide plate and gradually decreases after flowing through the guide plate to the baffle.

[0043] Compared to simply using baffles, the vortex generator cylinder increases dust collisions and effectively guides the flue gas to continue colliding with the multi-layered baffles on the right side of the guide baffle. This demonstrates that optimizing the inertial dust separation device by combining the vortex generator cylinder and multi-layered baffles can increase the collisions of dust-laden flue gas, thereby improving the separation efficiency of dust particles.

[0044] Example 6 To more intuitively analyze and compare the changes in separation efficiency and resistance between the present invention and the unoptimized device under simulation, the separation efficiency and resistance results are listed in a table and plotted as bar charts and line graphs for comparison, as shown in Table 2 and... Figure 4As shown.

[0045] Table 2. Comparison of Separation Efficiency and Resistance

[0046] Compared with a dust separation device without any optimization device, the present invention significantly improves the total separation efficiency of dust particles, as shown in Table 2. Table 2 compares the dust separation efficiency and resistance of the present invention with that of an inertial dust separation device without any optimization device, where a represents the case without any optimization device, and b represents the present invention.

[0047] Depend on Figure 4 It can be seen that the present invention does not improve the separation efficiency of dust particles smaller than 25 μm. For dust particles of 25 μm and above, the increase in separation efficiency is greater with the increase in particle size. This trend may indicate that the present invention significantly improves the separation efficiency of large-diameter particles. In addition, the system resistance of the present invention is slightly higher than that without any optimization device, but the increase is relatively small.

[0048] As shown in Table 2, compared to the case without any optimization device, the overall dust separation efficiency of this invention is improved by nearly 20%. For dust particles smaller than 35 μm, this invention has almost no effect on improving their separation efficiency; for dust particles larger than 35 μm, the improvement in separation efficiency gradually increases, with increases of 5%, 22.7%, and 28.8% for dust particles of 35 μm, 50 μm, and 80 μm, respectively. This invention can effectively improve the separation efficiency of dust particles in dusty flue gas, especially the separation efficiency of large-diameter particles.

Claims

1. A dust separation device based on a combination of vortex shear and baffle inertial collision, characterized in that: Includes a main bend (1), a vortex generation cylinder (2) is provided inside the main bend (1), a hopper (4) is provided at the bottom of the main bend (1), a flow guide baffle (3) is provided through the main bend (1) and the hopper (4), and an ash discharge bin (6) is provided at the bottom of the hopper (4). The ash hopper (4) has an inverted frustum-shaped structure; The inner wall of the ash hopper (4) is a dust collection wall (7), which is a heat-insulating and fire-resistant lining. The surface of the vortex-generating cylinder (2) is provided with triangular ribs (8); The triangular ribs (8) are spirally and equidistantly distributed on the surface of each vortex-generating cylinder (2); The flow guide baffle (3) is provided with several multi-layer baffles (5) of the same size on one side, and the multi-layer baffles (5) are located inside the ash hopper (4); Each of the multi-layer baffles (5) has an arc-shaped downward bend (9) at its lower tail.

2. The dust separation method based on the combination of vortex shear and baffle inertial collision in the dust separation device according to claim 1, characterized in that: Specifically, the process includes the following steps: Dust-laden flue gas enters from the main bend pipe (1), first passes through the vortex street inside the main bend pipe (1) to generate a cylinder (2) and undergo boundary layer separation, causing the dust-laden flue gas to collide with the guide baffle (3) and the inner wall of the main bend pipe (1) respectively. The guide baffle (3) guides the dust-laden flue gas to flow in the direction of the ash discharge bin (6). The dust-laden flue gas flows to one side of the guide baffle (3) and collides with the multi-layer baffle (5). The dust particles that have not been separated from the flue gas after passing through the cylinder (2) generated by the vortex street are separated by inertial collision.

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