Venturi scrubber

Abstract

The present application provides a kind of venturi scrubber, including inlet straight pipe section, inlet converging section, throat injection section and outlet diverging section connected in turn from air inlet end to air outlet end, also including star array gas mixing unit, gas mixing guide pipe and pressure reducer;Gas mixing guide pipe communicates inlet straight pipe section, pressure reducer, star array gas mixing unit and outlet diverging section to form bypass airflow channel;Star array gas mixing unit is set outside outlet diverging section, and a plurality of gas mixing channels are provided in star array gas mixing unit, and each gas mixing channel is communicated with the inside of outlet diverging section.The present application divides a bypass airflow from inlet straight pipe section, enters star array gas mixing unit after reducing pressure by gas mixing guide pipe and pressure reducer, is divided into several airflows by gas mixing channel, and the airflow is evenly entered outlet diverging section to destroy original wall liquid film, again atomizes wall liquid film to form atomized droplets, enhances the stirring degree of gas-liquid-solid three-phase of venturi scrubber, passively strengthens the overall atomization capacity, and improves filtration efficiency.

Description

Technical Field

[0001] This invention relates to a Venturi scrubber, which can be applied to multiple engineering fields such as nuclear safety, industrial dust removal, and toxic substance decontamination. It is used to remove impurities such as dust particles, harmful gases, and radioactive aerosols contained in gases, thereby preventing these impurities from causing harm to workers, the public, and the environment. Background Technology

[0002] With the rapid development of nuclear power technology and nuclear energy utilization, self-priming Venturi scrubbers have been introduced into the containment filtration and emission systems of nuclear power plants. The working principle of a self-priming Venturi scrubber is as follows: The gas phase carrying impurities is accelerated through a converging nozzle, forming a low-pressure zone at the throat. This low pressure zone, combined with the gravity head of the liquid phase, creates a static pressure difference, drawing the liquid phase into the Venturi. Due to the velocity difference between the gas and liquid phases, there is a dragging and shearing effect, causing the gas and liquid phases to form atomized droplets. These droplets then trap the impurities in the liquid phase through inertial collisions and other mechanisms. The impact and fall of the atomized droplets at the outlet diffuser section causes them to form a stable, flowing, wall-attached liquid film. Since the surface area of ​​the liquid film is much smaller than that of the atomized droplets, the liquid film in traditional Venturi scrubbers contributes little to impurity removal, thus limiting filtration performance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a Venturi scrubber.

[0004] The technical solution adopted in this invention is: a Venturi scrubber, comprising an inlet straight pipe section, an inlet tapering section, a throat ejector section and an outlet tapering section connected sequentially from the air inlet end to the air outlet end, and further comprising a star array gas mixing unit, a gas mixing guide pipe and a pressure reducing component;

[0005] The gas mixing duct connects the inlet straight pipe section, the pressure reducing component, the star array gas mixing unit, and the outlet gradually expanding section to form a bypass airflow channel;

[0006] The star array gas mixing unit is fitted outside the outlet expansion section. The star array gas mixing unit is provided with several gas mixing channels, and each gas mixing channel is connected to the interior of the outlet expansion section.

[0007] Furthermore, the star array gas mixing unit preferably includes a gas mixing inlet pipe, an annular pipe, and a narrow gas flow pipe;

[0008] One end of the gas-mixing inlet pipe is connected to the outlet end of the gas-mixing guide pipe, and the other end of the gas-mixing inlet pipe is connected to the annular pipe.

[0009] The annular tube is sleeved outside the outlet expansion section. The narrow airflow tube connects the annular tube and the outlet expansion section. The narrow airflow tube is arranged along the circumference of the annular tube. An annular flow channel is formed inside the annular tube. A narrow airflow channel is formed inside the narrow airflow tube. The annular flow channel is connected to several narrow airflow channels to form each of the gas mixing channels.

[0010] Furthermore, preferably, the gas mixing inlet pipe is symmetrically arranged along the center of the star array gas mixing unit, and correspondingly, the gas mixing guide pipe is symmetrically arranged.

[0011] Furthermore, it is preferable that the narrow airflow tube is a circular tube, or that the narrow airflow tube is an elliptical narrow airflow tube.

[0012] Furthermore, the elliptical airflow pipe preferably includes a straight pipe section and an arc-shaped pipe section connected to both ends of the straight pipe section.

[0013] Furthermore, it is preferable that the narrow airflow duct is uniformly distributed along the axis of the outlet widening section.

[0014] Furthermore, preferably, the throat ejector section includes a throat straight tube section and a plurality of ejector tubes, the throat straight tube section is coaxially arranged with the inlet constriction section and the outlet expansion section, and the ejector tubes are connected to the throat straight tube section.

[0015] Furthermore, it is preferable that the ejector tubes are evenly distributed along the axis of the straight section of the throat.

[0016] Furthermore, the pressure-reducing component is preferably a throttling orifice plate.

[0017] Furthermore, preferably, the inlet straight pipe section, the inlet tapering section, the throat ejector section, the outlet expanding section, the star array gas mixing unit, the mixing guide pipe, and the pressure reducing component are all coated with an anti-corrosion layer.

[0018] The beneficial effects of implementing the present invention are as follows: The Venturi scrubber of the present invention uses an inlet straight pipe section to stabilize the gas phase carrying impurities. The acceleration of the gas phase in the inlet converging section forms a high-speed airflow at the outlet. A sufficient negative pressure is formed in the throat ejector section, creating a static pressure difference with the gravity head of the scrubbing liquid, which allows the scrubbing liquid to be ejected into the Venturi scrubber through the throat ejector section. The high-speed gas phase shears the liquid phase in the throat ejector section, forming atomized droplets. Some of the atomized droplets are concentrated at the end of the throat ejector section and the outlet expanding section due to… The impacted liquid falls back and adheres to the wall surface, forming a continuous liquid film. The bypass airflow, branched off from the inlet straight pipe section, passes through the gas mixing guide pipe and pressure reducing device before entering the star array gas mixing unit. The gas mixing channel divides the airflow into several streams that enter the outlet diffuser section evenly, disrupting the original wall-attached liquid film and atomizing it into atomized droplets. The atomized droplets then filter and remove impurities in the gas phase through retention mechanisms such as inertial collision, interception, and Brownian diffusion in the throat ejection section and the outlet diffuser section.

[0019] This invention utilizes a star array gas mixing device to disrupt the stable liquid film adhering to the wall of the outlet diffuser section by splitting a small bypass airflow from the main gas path. This enhances the atomization characteristics of the Venturi scrubber, increases the mixing degree of the gas-liquid-solid three-phase mixture in the Venturi scrubbing gas, and further improves the filtration efficiency of the Venturi scrubbing gas. Under accident emission conditions, this device is expected to achieve a filtration efficiency of 99.9% for aerosols, simplifying the multi-stage design of current containment filtration emission systems. It meets filtration requirements with a two-stage or single-stage filtration system, reducing engineering costs. It offers numerous advantages, including passive operation, simplicity and reliability, low processing requirements and costs, superior filtration performance, and low pressure drop loss. It can be applied in various engineering fields such as nuclear safety, industrial dust removal, and toxic substance decontamination. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the Venturi scrubber of the present invention;

[0021] Figure 2 yes Figure 1 Front view;

[0022] Figure 3 yes Figure 2 A cross-sectional view of the throat ejector segment along AA;

[0023] Figure 4 yes Figure 2 A cross-sectional view of the throat ejector segment along the CC.

[0024] Figure 5 yes Figure 2 A cross-sectional view of the throat ejector segment along the BB.

[0025] Figure 6 This is a cross-sectional view of the elliptical narrow airflow pipe in an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] like Figures 1-5 As shown, the present invention provides a Venturi scrubber, comprising an inlet straight pipe section 1, an inlet tapering section 2, a throat ejector section 3, and an outlet diffuser section 4 connected sequentially from the inlet end to the outlet end. The inlet straight pipe section 1, inlet tapering section 2, throat ejector section 3, and outlet diffuser section 4 are connected sequentially by welding, ensuring the coaxiality of each section during welding and that they are internally interconnected to form a main airflow channel. The main airflow carrying impurities passes through the inlet straight pipe section 1, which is used to stabilize the incoming gas flow. The inlet converging section 2 accelerates the gas, creating a high-speed airflow at the outlet. This creates a sufficient negative pressure at the throat ejector section 3, which, combined with the gravity head of the washing liquid, forms a static pressure difference that allows the washing liquid to be ejected into the Venturi scrubber through the throat ejector section 3. The high-speed gas phase shears the liquid phase within the throat ejector section 3, forming atomized droplets. Some of these atomized droplets fall back due to impact at the end of the throat ejector section 3 and the outlet expanding section 4, adhering to the wall surface and forming a continuous liquid film.

[0028] The Venturi scrubber of this invention also includes a star array gas mixing unit 7, a gas mixing guide pipe 5, and a pressure reducing component 6. The gas mixing guide pipe 5 connects the inlet straight pipe section 1, the pressure reducing component 6, the star array gas mixing unit 7, and the outlet diffuser section 4 to form a bypass airflow channel. That is, in this invention, a small stream of bypass airflow is drawn from the main airflow in the inlet straight pipe section 1. The bypass airflow flows along the bypass airflow channel to the outlet diffuser section 4. The bypass airflow flows out from the inlet straight pipe section 1 through the gas mixing guide pipe 5 and flows to the pressure reducing component 6. The pressure reducing component 6 reduces the pressure of the bypass airflow, preventing the bypass airflow from being directly introduced and causing the pressure in the diffuser section to be too high, which would lead to pressure issues in the Venturi scrubber. Excessive pressure reduction affects the ejection capability and normal operation of the Venturi scrubber. After the airflow is depressurized, it enters the star array gas mixing unit 7. The star array gas mixing unit 7 is installed outside the outlet diffuser section 4. The star array gas mixing unit 7 has several gas mixing channels 8. All gas mixing channels 8 are connected to the interior of the outlet diffuser section 4. After depressurization, the airflow entering the star array gas mixing device is divided into several narrow airflows along the extension direction of the gas mixing channels 8 and enters the outlet diffuser section 4 evenly, destroying the original wall-adhering liquid film and atomizing the wall-adhering liquid film into atomized droplets. The atomized droplets filter and remove impurities in the gas phase through retention mechanisms such as inertial collision, interception, and Brownian diffusion in the throat ejection section 3 and the outlet diffuser section 4.

[0029] In a specific embodiment, the star array gas mixing unit 7 includes a gas mixing inlet pipe 71, an annular pipe 72, and a narrow airflow pipe 73; one end of the gas mixing inlet pipe 71 is connected to the outlet end of the gas mixing guide pipe 5, and the other end of the gas mixing inlet pipe 71 is connected to the annular pipe 72; the annular pipe 72 is sleeved outside the outlet gradually expanding section 4, one end of the narrow airflow pipe 73 is connected to the annular pipe 72, and the other end is connected to the outlet gradually expanding section 4. The narrow airflow pipe 73 is arranged along the circumference of the annular pipe 72, forming an annular flow channel 74 inside the annular pipe 72, and forming a narrow airflow channel 75 inside the narrow airflow pipe 73. The annular flow channel 74 and several narrow airflow channels 75 are connected to form several gas mixing channels 8 respectively. The airflow, after being depressurized by the depressurizing component 6, flows into the annular pipe 72 through the gas mixing inlet pipe 71 and flows along the annular flow channel 74, forming a uniform airflow. When it flows through the narrow airflow pipe 73 of this invention, it is divided into several narrow airflows. The narrow airflows impact the inner wall of the outlet gradually expanding section 4, thereby destroying the original wall-adhering liquid film. Through the structural design of the star array gas mixing unit 7, this invention utilizes a small bypass airflow in the main gas path to destroy the stable liquid film adhering to the wall of the outlet gradually expanding section 4, thereby enhancing the atomization characteristics of the Venturi scrubber, increasing the mixing degree of the gas-liquid-solid three phases of the Venturi scrubber, and further improving the filtration efficiency of the Venturi water washing gas. This device is expected to achieve a filtration efficiency of 99.9% for aerosols under accident emission conditions, simplifying the multi-stage design of current containment filtration emission systems. It can meet filtration requirements by relying on a two-stage or single-stage filtration system, reducing engineering costs. It has many advantages such as being passive, simple and reliable, having low processing requirements and costs, excellent filtration performance, and low pressure drop loss. It can be applied to multiple engineering fields such as nuclear safety, industrial dust removal, and decontamination of toxic substances.

[0030] Furthermore, the annular tube 72 and each narrow gas flow tube 73 should be at the same level, which facilitates processing and ensures the stability of the device. In the star array gas mixing unit 7, the annular tube 72, each narrow gas flow tube 73, and the outlet diffuser section 4 are all connected by welding. After welding, polishing and grinding are performed, and a coating is added to ensure the reliability of the weld.

[0031] In one specific embodiment, the gas mixing inlet pipe 71 is symmetrically arranged along the center of the star array gas mixing unit 7, and correspondingly, the gas mixing guide pipe 5 is symmetrically arranged. This ensures that the airflow introduced from the bypass airflow channel can instantly cancel out the impact force on the star array gas mixing unit 7, thus ensuring the stability of the device operation.

[0032] In this invention, the number of air mixing duct 5, air mixing inlet pipe 71 and narrow airflow pipe 73 is determined by the actual washing environment and working conditions. When designing the distribution of air mixing inlet pipe 71 and narrow airflow pipe 73, it is necessary to ensure the stability of the star array air mixing unit 7 and the Venturi scrubber when the bypass flow and narrow airflow are introduced.

[0033] The narrow airflow pipe 73 of this invention is a relatively narrow pipe, which allows the airflow to be split into several smaller airflows. While creating a certain impact force on the inner wall of the outlet gradually expanding section 4, it also achieves an airflow turbulence effect, ensuring that the impact force is insufficient to affect the stability of the entire device. For example, the narrow airflow pipe 73 can be a circular pipe, or an elliptical narrow airflow pipe 73. Preferably, the narrow airflow pipe 73 is an elliptical narrow airflow pipe 73. The design of the elliptical narrow airflow pipe 73 can increase the impact area and turbulence area of ​​the airflow, resulting in a better turbulence effect. Specifically, as... Figure 6 As shown, the elliptical narrow airflow pipe 73 includes a straight pipe section 732 and an arc pipe section 731 connected to both ends of the straight pipe section 732. The straight pipe section 732 and the arc pipe section 731 are an integral structure.

[0034] In one specific embodiment, the narrow airflow pipe 73 is evenly distributed along the axis of the outlet expansion section 4. This design ensures that the incoming airflow is uniform, thus guaranteeing the stability of the star array gas mixing device and the outlet expansion section 4. Furthermore, it covers all positions on the inner wall of the outlet expansion section 4, thereby causing the airflow to break up all the liquid films that were originally moving against the wall, and atomize the liquid films against the wall into atomized droplets, thereby enhancing the atomization capability of the Venturi scrubber.

[0035] In one specific embodiment, such as Figures 3-4 As shown, the throat ejector section 3 includes a throat straight pipe section 31 and several ejector tubes 32. The throat straight pipe section 31 is coaxially arranged with the inlet converging section 2 and the outlet expanding section 4, and the ejector tubes 32 are connected to the throat straight pipe section 31. The negative pressure zone formed by the high-speed airflow carrying impurities in the throat straight pipe section 31 and the static pressure difference formed by the gravity head cause the washing liquid to be ejected into the Venturi scrubber through the ejector tubes 32. The washing liquid injected into the Venturi scrubber begins to mix and shear with the high-speed airflow in the throat straight pipe section 31 to form atomized droplets, which remove impurities entrained in the gas phase through water washing. The number of rows and quantities of each ejector tube 32 and the angle formed with the wall of the throat straight pipe section 31 are determined by the actual water washing environment and working conditions; furthermore, it is preferable that the ejector tubes 32 are evenly distributed along the axis of the throat straight pipe section 31.

[0036] In this invention, the pressure-reducing component 6 functions to lower the bypass airflow pressure, preventing the bypass airflow from directly entering and causing excessive pressure in the outlet diffuser section 4, which would lead to excessive pressure drop in the Venturi scrubber and affect its ejection capacity and normal operation. Furthermore, the pressure-reducing component 6 is a throttling orifice plate. Different sizes of throttling orifice plates can be adjusted or replaced to meet the filtration requirements of different washing conditions.

[0037] In a specific embodiment, considering that the Venturi scrubber may be in a weakly alkaline washing environment, an anti-corrosion layer is plated inside the inlet straight pipe section 1, the inlet tapering section 2, the throat ejector section 3, the outlet expanding section 4, the star array gas mixing unit 7, the gas mixing guide pipe 5, and the pressure reducing component 6. Specifically, the anti-corrosion layer can be a cadmium anti-corrosion layer, thereby achieving the anti-corrosion effect.

[0038] The beneficial effects of implementing the present invention are as follows: The Venturi scrubber of the present invention uses an inlet straight pipe section to stabilize the gas phase carrying impurities. The acceleration of the gas phase in the inlet converging section forms a high-speed airflow at the outlet. A sufficient negative pressure is formed in the throat ejector section, creating a static pressure difference with the gravity head of the scrubbing liquid, which allows the scrubbing liquid to be ejected into the Venturi scrubber through the throat ejector section. The high-speed gas phase shears the liquid phase in the throat ejector section, forming atomized droplets. Some of the atomized droplets collide at the end of the throat ejector section and the outlet expanding section. The liquid is knocked back and adheres to the wall to form a continuous liquid film. The bypass airflow, which is separated from the inlet straight pipe section, passes through the gas mixing guide pipe and the pressure reducing device before entering the star array gas mixing unit. The gas is then divided into several airflows that enter the outlet diffuser section evenly, destroying the original wall-adhering liquid film and atomizing it into atomized droplets. The atomized droplets filter and remove impurities in the gas phase through retention mechanisms such as inertial collision, interception, and Brownian diffusion in the throat ejection section and the outlet diffuser section.

[0039] This invention utilizes a star array gas mixing device to disrupt the stable liquid film adhering to the wall of the outlet diffuser section by splitting a small bypass airflow from the main gas path. This enhances the atomization characteristics of the Venturi scrubber, increases the mixing degree of the gas-liquid-solid three-phase mixture in the Venturi scrubbing gas, and further improves the filtration efficiency of the Venturi scrubbing gas. Under accident emission conditions, this device is expected to achieve a filtration efficiency of 99.9% for aerosols, simplifying the multi-stage design of current containment filtration emission systems. It meets filtration requirements with a two-stage or single-stage filtration system, reducing engineering costs. It offers numerous advantages, including passive operation, simplicity and reliability, low processing requirements and costs, superior filtration performance, and low pressure drop loss. It can be applied in various engineering fields such as nuclear safety, industrial dust removal, and toxic substance decontamination.

[0040] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A Venturi scrubber, comprising an inlet straight pipe section (1), an inlet converging section (2), a throat ejector section (3), and an outlet diffusing section (4) connected sequentially from the inlet end to the outlet end, characterized in that, It also includes a star array gas mixing unit (7), a gas mixing duct (5), and a pressure reducing component (6); The gas mixing duct (5) connects the inlet straight pipe section (1), the pressure reducing component (6), the star array gas mixing unit (7) and the outlet gradually expanding section (4) to form a bypass airflow channel; The star array gas mixing unit (7) is sleeved outside the outlet expansion section (4). The star array gas mixing unit (7) is provided with a number of gas mixing channels (8). Each gas mixing channel (8) is connected to the interior of the outlet expansion section (4), and the outlet of each gas mixing channel (8) is arranged facing the inner wall of the outlet expansion section (4) to uniformly introduce the bypass gas flow and impact the wall-attached liquid film.

2. The Venturi scrubber according to claim 1, characterized in that, The star array gas mixing unit (7) includes a gas mixing inlet pipe (71), an annular pipe (72), and a narrow gas flow pipe (73); One end of the gas-mixing inlet pipe (71) is connected to the outlet end of the gas-mixing guide pipe (5), and the other end of the gas-mixing inlet pipe (71) is connected to the annular pipe (72). The annular pipe (72) is sleeved outside the outlet expansion section (4). The narrow airflow pipe (73) connects the annular pipe (72) and the outlet expansion section (4). The narrow airflow pipe (73) is arranged along the circumference of the annular pipe (72). An annular flow channel (74) is formed inside the annular pipe (72). A narrow airflow channel (75) is formed inside the narrow airflow pipe (73). The annular flow channel (74) and several narrow airflow channels (75) are connected to form several gas mixing channels (8).

3. The Venturi scrubber according to claim 2, characterized in that, The gas mixing inlet pipe (71) is symmetrically arranged along the center of the star array gas mixing unit (7), and correspondingly, the gas mixing guide pipe (5) is symmetrically arranged.

4. The Venturi scrubber according to claim 2, characterized in that, The narrow airflow tube (73) is a circular tube, or the narrow airflow tube (73) is an elliptical narrow airflow tube.

5. The Venturi scrubber according to claim 4, characterized in that, The elliptical narrow airflow pipe includes a straight pipe section (732) and an arc-shaped pipe section (731) connected to both ends of the straight pipe section (732).

6. The Venturi scrubber according to claim 2, characterized in that, The narrow airflow pipe (73) is evenly distributed along the axis of the outlet expansion section (4).

7. The Venturi scrubber according to claim 1, characterized in that, The throat ejector section (3) includes a throat straight tube section (31) and several ejector tubes (32). The throat straight tube section (31) is coaxially arranged with the inlet constriction section (2) and the outlet expansion section (4). The ejector tubes (32) are connected to the throat straight tube section (31).

8. The Venturi scrubber according to claim 7, characterized in that, The ejector tubes (32) are evenly distributed along the axis of the straight section (31) of the throat.

9. The Venturi scrubber according to claim 1, characterized in that, The pressure-reducing component (6) is a throttling orifice plate.

10. The Venturi scrubber according to claim 1, characterized in that, The inlet straight pipe section (1), the inlet tapering section (2), the throat ejector section (3), the outlet expanding section (4), the star array gas mixing unit (7), the gas mixing guide pipe, and the pressure reducing component (6) are all coated with an anti-corrosion layer.

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