Venturi dust removal device based on fluid mechanics coanda effect

Abstract

The application provides a Venturi tube dust removal device based on a fluid mechanics Coanda effect, which comprises a contraction section, a throat section, an expansion section, an outlet section, a dust collection component and a spraying assembly for spraying liquid mist to dust-containing gas which are sequentially connected; the throat section is a straight pipe section, the contraction section and the expansion section are inner cone type pipe sections, and the cone top of the contraction section and the expansion section is connected to the two ends of the throat section; the inner wall of the expansion section is provided with a flow guide lining which has a non-linear smooth curved surface gradually expanding along the airflow direction for guiding the dust-containing gas to flow along the inner wall of the flow guide lining to form wall-attached airflow.The device of the application solves the problems of insufficient dust capture rate of the traditional Venturi tube dust remover for dust with a diameter less than 2.5 microns and difficulty in realizing stable and effective particle interception by arranging the flow guide lining with the non-linear smooth curved surface gradually expanding along the airflow direction on the inner wall of the expansion section to guide the dust-containing gas to flow along the inner wall of the flow guide lining by using the Coanda effect.

Description

Technical Field

[0001] This application relates to the field of dust removal equipment technology, specifically to a Venturi tube dust removal device based on the Coanda effect of fluid mechanics. Background Technology

[0002] Industries such as mining, cement manufacturing, power generation, metallurgy, and chemicals emit large amounts of dust, with particle sizes ranging from inhalable particulate matter (PM10) to fine particulate matter (PM2.5), seriously endangering human health and the environment. To control industrial dust emissions, various industrial dust collection devices have emerged, including cyclone separators, bag filters, wet electrostatic precipitators, cartridge filters, and venturi tube filters. Among these, venturi tube filters are widely used in high-concentration dust environments due to their compact structure.

[0003] Traditional Venturi dust collectors accelerate airflow in the contraction section, creating a low-pressure zone at the throat that promotes collisions between dust and droplets, followed by deceleration and settling in the expansion section. However, they suffer from the following drawbacks: the rapid deceleration of airflow in the expansion section easily leads to backflow and turbulence, causing some particles to bounce back or escape, especially resulting in insufficient capture rate for dust particles with a diameter of less than 2.5 micrometers; when the spray system is superimposed with the gas-solid two-phase flow, the water mist distribution is uneven, the particle capture path is highly random, and it is difficult to achieve stable and effective particulate matter interception. Utility Model Content

[0004] The purpose of this invention is to provide a Venturi tube dust collector based on the Coanda effect of fluid dynamics, which can effectively solve the problem that traditional Venturi tube dust collectors have insufficient capture rate for dust with a diameter of less than 2.5 micrometers and are difficult to achieve stable and effective particulate matter interception.

[0005] This application is achieved through the following technical solution, specifically: A Venturi tube dust collector based on the Coanda effect of fluid dynamics includes: a contraction section, a throat section, an expansion section, an outlet section, a dust collection component connected in sequence, and a spray assembly for spraying liquid mist into the dust-laden gas. The throat section is a straight pipe section, and the contraction section and the expansion section are inner conical pipe sections, with the cone tops of the contraction section and the expansion section connected to both ends of the throat section; the inner wall of the expansion section is provided with a flow guide liner, which has a non-linear smooth curved surface that gradually expands along the airflow direction, used to guide the dust-laden gas to adhere to the inner wall of the flow guide liner and flow to form a wall-attached airflow.

[0006] In this scheme, by employing an inner conical contraction section and an expansion section, and by setting a guide liner with a nonlinear smooth curved surface that gradually expands along the airflow direction on the inner wall of the expansion section, the Coanda effect is utilized to guide the dust-laden gas to adhere to the inner wall of the guide liner, forming a wall-attached airflow. This effectively reduces the turbulence of the airflow in the expansion section and prolongs the settling path of particles in the boundary layer, reducing the possibility of particle rebound and escape, and improving the collection efficiency of fine particles. Simultaneously, because the airflow flows along the inner wall of the guide liner, the contact between the dust-laden gas and the sprayed liquid mist is more thorough and uniform, increasing the collision probability between particles and droplets, thereby further improving dust removal efficiency and stability.

[0007] As an improvement to the flow-guiding liner in this application, the flow-guiding liner is a flexible transparent liner, and the flow-guiding liner is detachably connected to the inner wall of the expansion section.

[0008] Furthermore, the nonlinear smooth surface of the flow guide liner has a preset curvature, the preset curvature being in the range of 20-40°.

[0009] Furthermore, the preset curvature is 30°.

[0010] As an improvement to the expansion section in this application, the diffusion angle of the expansion section is 15-20°.

[0011] As an improvement to the contraction segment in this application, the contraction angle of the contraction segment is 22.62-29.05°.

[0012] As an improvement to the throat segment in this application, the ratio of the length to the inner diameter of the throat segment is greater than or equal to 10:1.

[0013] As an improvement to the spray assembly of this application, the spray assembly includes a micro-nozzle disposed at the inlet section of the throat section or the expansion section.

[0014] As an improvement to the outlet section in this application, the outlet section is a curved exhaust pipe, and the lower part of the outlet section is connected to the dust collection component.

[0015] The beneficial effects of this application are as follows: This application's solution employs an inner conical contraction section and an expansion section, along with a guide liner on the inner wall of the expansion section featuring a non-linear, smooth curved surface that gradually widens along the airflow direction. Utilizing the Coanda effect, it guides the dust-laden gas to adhere to the inner wall of the guide liner, forming a wall-attached airflow. This effectively reduces the turbulence of the airflow in the expansion section and extends the settling path of particles in the boundary layer, reducing the possibility of particle rebound and escape, and improving the collection efficiency of fine particles. Simultaneously, because the airflow flows along the inner wall of the guide liner, the contact between the dust-laden gas and the sprayed liquid mist is more thorough and uniform, increasing the collision probability between particles and droplets, thereby further enhancing dust removal efficiency and stability.

[0016] In addition to the technical problems solved by this utility model, the technical features constituting the technical solution, and the advantages brought about by the technical features of these technical solutions as described above, other technical problems that this utility model can solve, other technical features contained in the technical solution, and the advantages brought about by these technical features will be further explained in detail with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a Venturi tube dust removal device based on the Coanda effect of fluid dynamics in an embodiment of this application; Figure 2 This is a schematic cross-sectional view of a Venturi dust removal device based on the Coanda effect of fluid dynamics in an embodiment of this application. Figure 3 This is a partially enlarged cross-sectional view of a Venturi dust removal device based on the Coanda effect of fluid dynamics in an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: 1. Contraction section; 2. Throat section; 3. Expansion section; 31. Guide liner; 4. Outlet section; 5. Spray assembly. Detailed Implementation

[0019] The following will be combined with the appendix Figures 1-2 The embodiments of the technical solution of this application are described in detail below. The following embodiments are only used to more clearly illustrate the technical solution of this application, and are therefore merely examples and should not be used to limit the scope of protection of this application. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0020] In view of the problems existing in the background technology or products, Figure 1 This paper shows a schematic diagram of a Venturi dust collector based on the Coanda effect in fluid dynamics, according to an embodiment of this application. Figure 2A schematic cross-sectional view of a venturi dust collector based on the Coanda effect in fluid dynamics is shown. Figure 3 It shows Figure 2 A magnified view of a section of the structure. (e.g.) Figure 1-3 As shown, this application provides a Venturi tube dust removal device based on the Coanda effect of fluid dynamics, including: a contraction section 1, a throat section 2, an expansion section 3, an outlet section 4, a dust collection component, and a spray assembly 5 for spraying liquid mist into the dust-laden gas, connected in sequence. The throat section 2 is a straight pipe section, the contraction section 1 and the expansion section 3 are inner conical pipe sections, and the cone tops of the contraction section 1 and the expansion section 3 are connected to the two ends of the throat section 2; the inner wall of the expansion section 3 is provided with a flow guide liner 31, which has a non-linear smooth curved surface that gradually expands along the airflow direction, and is used to guide the dust-laden gas to adhere to the inner wall of the flow guide liner 31 and flow to form a wall-attached airflow.

[0021] Specifically, the contraction section 1, as the foremost end of the Venturi dust collector, has its end furthest from the throat section 2 as the inlet section for the dust-laden gas. It is typically directly connected to the exhaust port of industrial production equipment, or connected to the exhaust port via an induced draft device. The contraction section 1 employs an internal cone design to accelerate the low-speed dust-laden airflow to a high-speed jet state, giving the airflow sufficient kinetic energy to achieve strong inertial motion of dust particles in the throat section 2. In one implementation, the contraction angle of the contraction section 1 is 22.62-29.05°. Controlling the contraction angle within this range balances the increase in the speed of the dust-laden airflow with the maintenance of inlet stability; a preferred contraction angle is 29.05°.

[0022] Throat section 2 is a short, straight pipe section with an inner diameter smaller than the inlet pipe diameter of the dust-laden airflow. It is a critical region where airflow velocity and pressure change abruptly. In this region, particles in the dust-laden airflow collide violently with water mist at high relative velocities, which facilitates particle adhesion and sedimentation. In one implementation, the ratio of the length to the inner diameter of throat section 2 is greater than or equal to 10:1.

[0023] The expansion section 3 is an inner conical pipe section, with its smaller diameter end connected to the throat section 2 and its larger diameter end connected to the outlet section 4. In contrast to the contraction section 1, the function of the expansion section 3 is to slow down the airflow and increase its pressure. In one implementation, the diffusion angle of the expansion section 3 is 15-20°, preferably 18.43°.

[0024] The inner wall of the expansion section 3 is provided with a flow guide liner 31, which has a non-linear smooth curved surface that gradually expands along the airflow direction. That is, the cross-sectional area of ​​the inner wall of the flow guide liner 31 gradually increases from the throat section 2 to the outlet section 4. The Coanda effect refers to the phenomenon that when a fluid (such as gas or liquid) flows along a convex curved surface, it tends to adhere to that surface and bend accordingly. In the Venturi dust collector of this embodiment, when the dust-laden gas enters the expansion section 3 at high speed from the throat section 2, according to the Coanda effect, the dust-laden gas deviates from its original flow direction and tends to flow along the convex surface. Due to the non-linear smooth curved surface design of the flow guide liner 31, the dust-laden gas will adhere to the inner wall of the flow guide liner 31 and flow, forming a wall-attached airflow. The airflow velocity gradient is very small within the wall layer, and the airflow flows along the curved surface, which greatly reduces the degree of turbulence in the expansion section. Due to inertia, the dust particles will have a different path of motion than the airflow. The particles in the wall layer will move along a longer path within the boundary layer, making it easier for them to separate from the main airflow and settle towards the inner wall, while also reducing the rebound energy of the particles.

[0025] The outlet section 4 is connected to the outlet of the expansion section 3, and its function is to discharge the decelerated gas from the venturi tube and restore its pressure. In one implementation, the outlet section 4 is a curved exhaust pipe, and the lower part of the outlet section 4 is connected to the dust collection component.

[0026] Specifically, outlet section 4 can be made of transparent plexiglass. Its curved structure can be used to evaluate the dust removal efficiency of the device, while also facilitating the observation of the stability of the airflow and water mist flow patterns. The dust collection component is used to collect dust particles separated from the dust-laden gas. It can be a dust collection bottle, settling chamber, or other collection device. The specific structure depends on the characteristics of the dust and the dust removal efficiency requirements.

[0027] The spray assembly 5 is used to spray liquid mist onto dust-laden gas. In one implementation, the spray assembly 5 includes micro-nozzles disposed at the inlet section of the throat section 2 or the expansion section 3. The micro-nozzles can spray high-pressure nano-water mist with a particle size controlled between 5 and 10 μm. The water mist can exchange momentum with the particulate matter, enhancing its agglomeration and sedimentation. Under the Coanda effect, the mist can be uniformly distributed along the wall, increasing the probability of dust capture.

[0028] In one implementation, the flow guide liner 31 is a flexible transparent liner, and the flow guide liner 31 is detachably connected to the inner wall of the expansion section 3.

[0029] Specifically, flexibility means that the flow guide liner 31 can adjust the curvature angle of its nonlinear smooth surface according to operating parameters such as dust particle size and wind speed, giving it good engineering flexibility. The transparency of the flow guide liner 31 allows for external observation during operation to monitor the airflow adhesion to the walls, the trajectory of particles, and the distribution of liquid mist. This provides direct visual evidence for studying the actual performance of the Coanda effect, diagnosing equipment operating status, and optimizing design parameters. The transparent material also makes it easier to inspect the flow guide liner 31 for wear, blockage, or damage. The detachable connection facilitates the installation, replacement, or maintenance of the flow guide liner 31. For example, the flow guide liner 31 is made of transparent TPU material and 3D printed. The detachable connection can be achieved in various ways, such as a snap-fit ​​connection, where grooves are provided on the inner wall edge of the expansion section 3, and the edge of the flow guide liner 31 is designed with a corresponding snap-fit ​​structure, allowing connection through insertion and removal; or using a special sealing ring or gasket, which is squeezed during installation to fix and seal the flow guide liner 31.

[0030] In one implementation, the nonlinear smooth surface of the guide liner 31 has a preset curvature, which ranges from 20 to 40°. Within this curvature range, the pressure and velocity distributions of the airflow flowing along the inner wall of the guide liner 31 reach a relatively ideal equilibrium. Preferably, the preset curvature is 30°. According to simulation and experimental results, a curvature angle of 30° is most conducive to forming stable wall-attached flow, which can significantly reduce turbulence intensity and prolong the settling path of particles in the boundary layer.

[0031] The working process of the Venturi dust collector in this application is as follows: 1. Dust-laden gas enters from the contraction section 1, and the airflow is accelerated; 2. The pressure in the throat section 2 drops sharply, the airflow velocity reaches its peak, and the particulate matter gains a large momentum; 3. Simultaneously, the spray component 5 sprays nano water mist into the airflow, forming a high relative velocity contact with the particulate matter; 4. The dust-laden water mist airflow enters the expansion section 3 and, under the action of the guide liner 31, adheres to the inner wall of the guide liner 31 and flows, forming the Coanda wall-attached flow. 5. Water mist and particulate matter are fully mixed in the wall-attached flow, and the particles settle along the inner wall of the guide liner 31 and are guided into the dust collection component.

[0032] The above working process was verified through CFD simulation and physical experiments. According to the turbulent kinetic energy simulation data, after adding the flow guide liner 3 to the Venturi dust removal device in this embodiment, the peak turbulent kinetic energy decreased by more than 30%, and the average dust removal quality improved by about 15%, verifying the orderliness of the flow field and the stable improvement of particulate matter collection efficiency.

[0033] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "set", "equipped with", "connected", and "installed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A Venturi dust collector based on the Coanda effect in fluid dynamics, comprising: The converging section (1), throat section (2), expanding section (3), outlet section (4), dust collection component, and spray assembly (5) for spraying liquid mist into dust-laden gas are connected in sequence; characterized in that, The throat section (2) is a straight pipe section, the contraction section (1) and the expansion section (3) are inner conical pipe sections, and the cone tops of the contraction section (1) and the expansion section (3) are connected to the two ends of the throat section (2); the inner wall of the expansion section (3) is provided with a flow guide liner (31), which has a non-linear smooth curved surface that gradually expands along the airflow direction, and is used to guide the dust-laden gas to adhere to the inner wall of the flow guide liner (31) and flow to form a wall-attached airflow.

2. The Venturi dust collector as described in claim 1, characterized in that, The flow guide liner (31) is a flexible transparent liner, and the flow guide liner (31) is detachably connected to the inner wall of the expansion section (3).

3. The venturi dust collector as described in claim 1 or 2, characterized in that, The nonlinear smooth surface of the flow guide liner (31) has a preset curvature, which is in the range of 20-40°.

4. The Venturi dust collector as described in claim 3, characterized in that, The preset curvature is 30°.

5. The Venturi dust collector as described in claim 1, characterized in that, The diffusion angle of the expansion section (3) is 15-20°.

6. The venturi dust collector as described in claim 1, characterized in that, The contraction angle of the contraction segment (1) is 22.62-29.05°.

7. The Venturi dust collector as described in claim 1, characterized in that, The ratio of the length of the throat segment (2) to its inner diameter is greater than or equal to 10:

1.

8. The Venturi dust collector as described in claim 1, characterized in that, The spray assembly (5) includes a micro-nozzle disposed at the inlet section of the throat section (2) or the expansion section (3).

9. The venturi dust collector as described in claim 1, characterized in that, The outlet section (4) is a curved exhaust pipe, and the lower part of the outlet section (4) is connected to the dust collection component.

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