An apparatus and method for the synergistic removal of mist droplets and fine particulate matter from flue gas.

Abstract

This invention discloses an apparatus and method for the synergistic removal of mist droplets and fine particulate matter from flue gas. The apparatus, installed within a desulfurization tower, includes: multiple atomizing nozzles fixed to condensate pipelines within the tower, used to atomize and spray condensate water to form a mist covering the cross-section of the desulfurization tower; multiple gas-liquid separation components fixed to a tray, each having a cylindrical structure. The flue gas inlet is located below the tray and tangentially to the cylindrical wall. The atomized flue gas enters the inlet and spirals upwards, where fine particulate matter collides and coalesces. The coalesced particles are captured by the condensate mist droplets and separated from the flue gas after centrifugal impact against the cylindrical wall; the flue gas outlet is located above the tray and symmetrically inclined downwards, with flue gas from adjacent gas-liquid separation components colliding to remove mist droplets and fine particulate matter. This invention eliminates the need for additional demisting equipment and increases the tower height, effectively removing mist droplets and fine particulate matter from flue gas.

Description

Technical Field

[0001] This invention relates to the field of flue gas emission control technology, and in particular to a device and method for the synergistic removal of mist droplets and fine particulate matter from flue gas. Background Technology

[0002] Production processes in energy, petrochemical, metallurgical, and chemical industries generate large amounts of flue gas, which contains significant amounts of SO2 and NO. X Hazardous substances such as dust (particulate matter) cause a series of environmental problems, including smog, acid rain, and the greenhouse effect, severely polluting the ecological environment. Currently, wet processes are commonly used in the environmental protection field for flue gas desulfurization and tail gas dust removal. For example, wet desulfurization involves spraying alkaline solution in a desulfurization absorption tower to wash away or absorb SO2 and dust (particulate matter) from the flue gas. However, the wet flue gas emitted after wet treatment still contains tiny droplets and particles composed of sulfuric acid, sulfates, liquid water, soluble salts, and soot, causing severe corrosion and scale buildup on process equipment and polluting the atmosphere, seriously harming the ecological environment. Wet desulfurization processes typically install demisters at the top of the absorption tower. Existing demisters can only remove droplets larger than 20μm (JB / T 10989-2010), and cannot remove even smaller droplets and dust (particulate matter) from the flue gas.

[0003] Existing technologies include direct spray cooling of flue gas by injecting a cooling medium into the flue gas. This cooling process causes the CPM (condensable particulate matter) in the flue gas to condense into fine particulate matter (PM2.5). 2.5 For particles with smaller diameters, after the flue gas cools, water vapor condenses and precipitates out using fine particles formed by CPM, as well as dust, SO3 aerosols (sulfuric acid mist), and other fine particles in the flue gas as condensation nuclei. The particle size of these fine particles increases, thus allowing them to be removed. However, this type of solution often requires a separate condensation tower and supporting condensation system, demister, etc., requiring a large floor area or significantly increasing the height of the desulfurization tower, resulting in high investment and making it difficult to meet the requirements for compact desulfurization system retrofits.

[0004] For example, Chinese patent application CN108014578A discloses a method and apparatus for purifying fine and condensable particles in coal-fired flue gas using low-temperature spraying. The method involves spraying saturated wet flue gas after wet desulfurization with cold mist, where the temperature of the cold mist does not exceed 20°C and the droplet diameter does not exceed 800 μm. This method can remove fine and condensable particles from coal-fired flue gas, but it requires a separate condensation tower, and the cooling path of the flue gas is relatively short, preventing the particle size of fine particles from increasing effectively, thus the removal efficiency needs improvement.

[0005] Therefore, there is an urgent need for a desulfurization tower that can effectively remove mist droplets and condensable particulate matter from flue gas without requiring additional floor space or significantly increasing the tower height.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide an apparatus and method for the synergistic removal of mist droplets and fine particulate matter from flue gas. The apparatus is installed inside a desulfurization tower, eliminating the need for additional demisting equipment and increasing the tower height, and effectively removing mist droplets and fine particulate matter from flue gas.

[0008] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides an apparatus for the coordinated removal of droplets and fine particulate matter from flue gas. The apparatus is installed inside a desulfurization tower and includes: multiple atomizing nozzles fixed to a condensate pipeline inside the desulfurization tower for atomizing and spraying condensate to form a condensate mist covering the cross-section of the desulfurization tower; multiple gas-liquid separation components fixed on a tray, the gas-liquid separation components having a cylindrical structure, with the flue gas inlet located below the tray and tangentially to the cylindrical wall; the atomized flue gas enters the flue gas inlet and spirals upward, where fine particulate matter collides and coalesces, and the coalesced particulate matter is captured by the condensate mist droplets and separated from the flue gas after centrifugal impact against the cylindrical wall; the flue gas outlet is located above the tray and symmetrically inclined downwards, with flue gas from adjacent gas-liquid separation components colliding to remove droplets and fine particulate matter.

[0009] Furthermore, in the above technical solution, the gas-liquid separation component may include: a straight cylindrical section, the outer wall of which is sealed to the tray, the flue gas inlet is located at the lower part of the straight cylindrical section, the flue gas outlet is located at the upper part of the straight cylindrical section, and the top of the straight cylindrical section is provided with an upper top plate; and a conical section, which is located below the straight cylindrical section and integrally formed with the straight cylindrical section, for receiving mist droplets carrying fine particulate matter from the cylindrical wall of the straight cylindrical section and discharging the collected liquid to the bottom of the tray.

[0010] Furthermore, in the above technical solution, the cylindrical structure of the gas-liquid separation component can be provided with double-layer walls, wherein the inner wall is a hollow wall, and a hollow structure is formed between the inner and outer walls.

[0011] Furthermore, in the above technical solution, an inverted conical lower top plate may be provided below the upper top plate, and a liquid inlet pipe is provided at the tip of the lower top plate. The liquid inlet pipe passes through the straight cylinder section and the conical cylinder section. Through holes are evenly distributed on the lower top plate, and part of the spiral rising flue gas from the straight cylinder section enters the space enclosed by the upper top plate and the lower top plate through the through holes and forms a collision.

[0012] Furthermore, in the above technical solution, a guide vane extending towards the upper top plate may be provided on the outer edge of the through hole.

[0013] Furthermore, in the above technical solution, the device may also include: a coalescing removal component, which is disposed above the gas-liquid separation component and receives the flue gas flowing out of the flue gas outlet of the gas-liquid separation component and after collision, for coalescing droplets and fine particulate matter in the flue gas, and after the particle size increases, the droplets and fine particulate matter are thrown towards the wall of the desulfurization tower under the action of centrifugal force.

[0014] Furthermore, in the above technical solution, the coalescing removal component may include: coalescing elements, which may be configured as brush-like structures and there may be multiple coalescing elements, one end of each coalescing element is fixed on the central shaft, and the multiple coalescing elements are evenly spaced along the axial and radial directions of the central shaft.

[0015] Furthermore, in the above technical solution, the coalescing removal component may also include an impeller and / or a drive motor; the impeller may be disposed below the coalescing element and fixed on the central shaft, and under the action of the rising flue gas, the impeller drives the central shaft and drives the coalescing element to rotate; the drive motor is connected to the central shaft and is used to drive the central shaft and drive the coalescing element to rotate.

[0016] According to a second aspect of the present invention, the present invention provides a method for the synergistic removal of droplets and fine particulate matter from flue gas, using the aforementioned apparatus, comprising the following steps: A. Flue gas after being condensed and atomized by spraying enters tangentially from the flue gas inlet of the gas-liquid separation component located at the bottom of the tray into the straight section of the gas-liquid separation component; B. The flue gas entering the straight section spirals upward, and the fine particulate matter collides and aggregates after collision. The aggregated particulate matter is captured by condensed water droplets and separated from the flue gas after centrifugal impact on the cylinder wall; C. The flue gas flows out at an angle downward at the outlet of the gas-liquid separation component, and the flue gas flowing out of adjacent gas-liquid separation components forms a collision, removing droplets and fine particulate matter.

[0017] Furthermore, in the above technical solution, the cylinder wall in step B can be a double-layer structure. After the mist droplets carrying fine particles pass through the hollow holes in the inner wall, they flow along the hollow part between the inner and outer walls to the conical section of the gas-liquid separation component and are discharged through the drain pipe.

[0018] Furthermore, in the above technical solution, the following steps may be included between steps B and C: the spirally rising flue gas impacts the top plate, removing droplets and fine particulate matter from the flue gas.

[0019] Furthermore, in the above technical solution, the following steps may be included between steps B and C: the spiraling flue gas collides with the space enclosed by the upper and lower top plates, removing the mist droplets and fine particulate matter in the flue gas.

[0020] Furthermore, in the above technical solution, the method may also include the following steps: D. The flue gas after collision continues to rise and enters the space where the coalescing removal component is located. The droplets and fine particles after coalescing on the coalescing element increase in size. Under the action of centrifugal force, the droplets and fine particles are thrown towards the wall of the desulfurization tower.

[0021] Furthermore, in the above technical solution, the process of throwing droplets and fine particulate matter toward the desulfurization tower wall under the action of centrifugal force is specifically as follows: under the action of rising flue gas, the impeller located below the coalescing element drives the central shaft and drives the coalescing element to rotate, thereby generating centrifugal force; and / or, the drive motor drives the central shaft and drives the coalescing element to rotate, thereby generating centrifugal force.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) Compared with the demisters of existing wet desulfurization systems, the present invention can effectively remove condensable particulate matter while removing mist droplets, thus having good environmental benefits;

[0024] 2) This invention can realize the in-situ replacement of existing demisters. After replacement, the tower height and floor area remain unchanged, and the weight of the tower changes little. Therefore, the tower foundation does not need to be reinforced, which can greatly reduce the modification cost.

[0025] 3) The sum of the flow areas of the flue gas inlet of the gas-liquid separation component of this invention is much smaller than the cross-sectional area of ​​the tower body. This increases the flow velocity of the flue gas carrying condensate droplets as it flows through the flue gas inlet, enhancing gas-liquid mixing and facilitating mass and heat transfer. It also increases the probability of droplet collision and aggregation with fine particles, as well as the probability of droplets capturing fine particles. After the flue gas enters the straight section, the flow velocity slows down and the residence time increases, which is beneficial for mass and heat transfer between gas and liquid. It also facilitates the continued condensation and precipitation of water vapor on the surface of droplets and fine particles, further increasing the particle size of droplets and fine particles. During the upward movement of the flue gas in the straight section, it impacts the lower top plate. Under the action of inertial force, the droplets and fine particles in the flue gas enter the cavity between the upper and lower top plates through the through holes, where the fine particles collide with each other. After impact and / or collision with the upper top plate, larger particles are formed, making them easier for droplets to capture. In addition, the cavity between the upper and lower top plates has only a gas inlet and no gas outlet, so fine particles entering this cavity cannot leave and can only be captured by droplets. When the flue gas leaves the straight section and enters the flue gas outlet, the flue gas flow area decreases and the flow velocity increases, further enhancing gas-liquid mixing and mass and heat transfer, further increasing the probability of droplet collision and agglomeration with fine particles and the probability of droplet capture of fine particles. After the flue gas passes through the flue gas outlet, the airflow direction becomes inclined downward, and the airflow between two adjacent gas-liquid separation components collides with each other, greatly enhancing the probability of droplet collision and agglomeration with fine particles, creating more favorable conditions for gas-liquid separation and droplet capture of fine particles.

[0026] 4) The flue gas inlet of the gas-liquid separation component of the present invention is tangentially arranged. The flue gas entering the straight section spirals upward, which can cause larger droplets in the flue gas to be thrown towards the inner wall of the straight section under the action of centrifugal force, realizing the first gas-liquid separation. When the straight section is a hollow structure, the droplets thrown towards the inner wall of the straight section can enter the hollow structure through the perforation, realizing efficient separation of droplets and flue gas and avoiding secondary entrainment of droplets by flue gas. Through the impact of flue gas with the lower top plate, droplets enter the cavity between the upper and lower top plates through the through holes, and flow downward under their own gravity and are discharged through the liquid inlet pipe, which can achieve further separation on the basis of the aforementioned first gas-liquid separation, and the separation effect is better. Through the guidance of the flue gas outlet, a second gas-liquid separation can be realized by colliding with the flue gas of the adjacent gas-liquid separation component. By setting the height of the overflow pipe to ensure that a certain liquid level is maintained in the tray, the efficiency of the second gas-liquid separation can be effectively enhanced.

[0027] 5) When flue gas enters the coalescing removal component, the unremoved droplets and fine particles will adhere to the surface of the coalescing element and continue to coalesce and grow. Through the action of centrifugal force, the coalesced droplets and fine particles are thrown towards the desulfurization tower wall, which can further remove droplets and fine particles in the flue gas, realize the third gas-liquid separation, and finally realize the staged removal of liquid droplets in the flue gas, which can effectively improve the removal efficiency of liquid droplets.

[0028] 6) Compared with existing demisting equipment, the present invention can not only achieve a third gas-liquid separation through the coalescing removal component, but also achieve self-cleaning without the need for flushing water, thus effectively reducing equipment investment and system water consumption.

[0029] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the device for the coordinated removal of mist droplets and fine particulate matter from flue gas according to the present invention.

[0031] Figure 2 This is a schematic diagram of the gas-liquid separation component in Embodiment 1 of the present invention.

[0032] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the device for the coordinated removal of mist droplets and fine particulate matter from flue gas according to the present invention.

[0033] Figure 4 This is a schematic diagram of the gas-liquid separation component in Embodiment 2 of the present invention.

[0034] Figure 5 This is a schematic diagram of the structure of Embodiment 3 of the device for the coordinated removal of mist droplets and fine particulate matter from flue gas according to the present invention.

[0035] Figure 6 This is a schematic diagram of the gas-liquid separation component in Embodiment 3 of the present invention.

[0036] Figure 7 This is a schematic diagram of the structure of Embodiment 4 of the device for the coordinated removal of mist droplets and fine particulate matter from flue gas according to the present invention.

[0037] Explanation of key figure labels:

[0038] 10 - Desulfurization tower body;

[0039] 100-Gas-liquid separation component, 101-Straight cylinder section, 101A-Outer wall, 101B-Inner wall, 102-Flue gas inlet, 103-Upper top plate, 104-Flue gas outlet, 105-Conical section, 106-Drain pipe, 107-Lower top plate, 108-Liquid inlet pipe, 109-Perforated hole, 110-Through hole, 111-Guide plate;

[0040] 200-Tray, 201-Overflow pipe; 300-Atomizing nozzle, 301-Condensate line; 400-Coalescing removal assembly, 401-Central shaft, 402-Coalescing element, 403-Fixed component, 404-Drive motor, 405-Impeller. Detailed Implementation

[0041] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0042] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0043] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0044] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0045] Example 1

[0046] like Figure 1 , Figure 2 As shown, this embodiment provides a device for the coordinated removal of mist droplets and fine particulate matter from flue gas. This device is installed inside the desulfurization tower 10 and allows for in-situ replacement of existing demisters without changing the tower height. The device includes atomizing nozzles 300 and gas-liquid separation components 100. Multiple atomizing nozzles 300 are fixed to condensate pipelines 301 within the desulfurization tower, used to atomize and spray condensate water to form a mist covering the cross-section of the desulfurization tower 10. Multiple gas-liquid separation components 100 are fixed to trays 200, which can be tilted (higher at the edges and lower in the middle). At least one overflow pipe 201 is provided on the tray 200 (it can be located at the lowest point in the center, and the upper end face of the overflow pipe is preferably higher than the upper end face of the tray to ensure that a certain amount of liquid is always present in the tray). The gas-liquid separation components have a cylindrical structure; preferably, but not limitingly, the gas-liquid separation components include a straight section 101 and a conical section 105. The outer wall of the straight section 101 is sealed to the tray 200. The flue gas inlet 102 is located at the lower part of the straight section 101, and the flue gas outlet 104 is located at the upper part of the straight section 101. The top of the straight section 101 is provided with an upper top plate 103. The conical section 105 is located below the straight section 101 and can be integrally formed with the straight section. It is used to receive the mist droplets containing fine particulate matter separated from the wall of the straight section and discharge the collected mist droplets to the bottom of the tray 200 through the drain pipe 106. The flue gas inlet 102 is located below the tray 200 and is transversely tangent to the cylinder wall. The flue gas, atomized and sprayed by the atomizing nozzle 300, enters the flue gas inlet 102 and spirals upward (reference). Figure 2 In the gas-liquid separation unit, fine particulate matter in the flue gas collides and agglomerates. Larger agglomerated particles are captured by condensate droplets and separated from the flue gas after centrifugal impact against the cylinder wall. The droplets, under centrifugal force, are thrown onto the inner wall of the straight section 101 and flow downstream to the conical section 105, eventually exiting the unit through the drain pipe. The flue gas outlet 104 is located above the tray and is symmetrically inclined downwards. Flue gas from adjacent gas-liquid separation units collides, further removing droplets and fine particulate matter. Droplets carrying fine particulate matter fall onto the tray 200 under the influence of gravity and inertia. Droplets and fine particulate matter in contact with the liquid surface of the tray 200 are quickly captured by the liquid and removed from the flue gas.

[0047] The working principle of this embodiment is as follows: During operation, condensate water forms a mist covering the cross-section of the desulfurization tower through the atomizing nozzle 300; flue gas passes through the condensate mist from bottom to top, and condensable particulate matter in the flue gas condenses and precipitates to form fine particulate matter. After the flue gas cools down, the water vapor in the flue gas condenses and precipitates using the fine particulate matter, dust, SO3 aerosol (sulfuric acid mist), and droplets formed after the condensation of condensable particulate matter as condensation nuclei, forming a "water-encased nucleus" structure, thereby increasing the particle size of the fine particulate matter. After collisions between the fine particulate matter, aggregates are generated. Furthermore, the particle size is increased, and fine particles are captured by the condensate droplets after colliding with them. The flue gas carrying droplets and fine particles enters the gas-liquid separation component 100 through the flue gas inlet 102. Because the sum of the flow areas of the flue gas inlet 102 is much smaller than the cross-sectional area of ​​the tower, the flow velocity of the flue gas carrying condensate droplets increases as it flows through the flue gas inlet 102, enhancing gas-liquid mixing, which is more conducive to mass and heat transfer, and increasing the probability of droplet collision and aggregation with fine particles, as well as the probability of droplets capturing fine particles. After the flue gas enters the gas-liquid separation component 100... The slower flow rate and longer residence time facilitate mass and heat transfer between gas and liquid, and promote the continued condensation and precipitation of water vapor on the surface of droplets and fine particles. During the spiral ascent, the fine particles collide and coalesce, further increasing their particle size and being captured by the condensate droplets. Under centrifugal force, the droplets are thrown onto the inner wall of the straight section 101 and flow downstream to the conical section 105, and then discharged from the gas-liquid separation component 100 through the drain pipe 106, achieving the first gas-liquid separation. The flue gas enters the upper part of the side wall of the straight section 101. With multiple flue gas outlets 104, the flue gas flow area is reduced and the flow velocity is increased, further enhancing gas-liquid mixing and mass and heat transfer. This further increases the probability of droplets colliding and coalescing with fine particles and the probability of droplets capturing fine particles. After passing through the flue gas outlets 104, the airflow direction becomes inclined downward, causing the flue gas flowing out between adjacent gas-liquid separation components 100 to collide. This greatly enhances the probability of droplets colliding and coalescing with fine particles, creating more favorable conditions for gas-liquid separation and droplet capture of fine particles, thus achieving a second separation of gas and liquid.

[0048] Example 2

[0049] like Figure 3 , Figure 4 As shown, this embodiment uses the same atomizing nozzle 300, tray 200 and overflow pipe 201 as in embodiment 1.

[0050] The gas-liquid separation component used in this embodiment differs from that in Embodiment 1 in that: the straight section 101 has a double-layered wall with a hollow structure between the two walls, and its inner wall 101B is provided with several perforated holes 109 (vertical strip holes are used in this embodiment); the conical section 105 is also a hollow structure with an open lower end to allow the liquid inside the hollow structure to be discharged through the drain pipe 106. Under the action of centrifugal force, the droplets pass through the vertical strip holes and enter the hollow structure between the inner and outer walls, flowing downward in a relatively independent space. Compared with Embodiment 1, this avoids secondary entrainment of flue gas.

[0051] The difference between Example 2 and Example 1 is that the flue gas after multiple collisions carries the remaining fine particulate matter and continues to rise into the coalescence removal component 400. For example... Figure 3 As shown, the coalescing removal component 400 is disposed above the gas-liquid separation component 100 and receives the cooled flue gas flowing out of the flue gas outlet 104 after collision. It is used to coalesce droplets and fine particulate matter in the flue gas, and after the particle size increases, the droplets and fine particulate matter are thrown towards the desulfurization tower wall under the action of centrifugal force. Specifically, the coalescing removal component 400 of this embodiment includes a central shaft 401, coalescing elements 402, a fixing member 403, and a drive motor 404. The central shaft 401 is fixed to the center line of the desulfurization tower body 10 by the fixing member 403 and can be driven to rotate by the drive motor 404. The outer edge of the fixing member 403 is fixed to the inner wall of the desulfurization tower body 10, and the fixing member 403 is provided with vents (not shown in the figure) that allow flue gas to pass through. The coalescing elements 402 are brush-like structures and there are multiple coalescing elements 402. One end of each coalescing element 402 is fixed to the central shaft 401. The multiple coalescing elements 402 are evenly spaced along the axial and radial directions of the central shaft 401. The overall arrangement of the coalescing elements 402 forms a brush array that basically covers the entire space of the desulfurization tower 100. The drive motor 404 is used to drive the central shaft 401 and drive the coalescing elements 402 to rotate.

[0052] The working principle of this embodiment differs from that of Embodiment 1 in that: after the flue gas enters the gas-liquid separation component 100, the fine particles collide and coalesce during the spiral ascent, and are further captured by condensed water droplets. Under the action of centrifugal force, the droplets are thrown onto the inner wall 101B of the straight section 101. The droplets thrown onto the inner wall 101B of the straight section enter the hollow structure through the perforated hole 109, achieving efficient separation of droplets from flue gas and avoiding secondary entrainment of droplets by flue gas; the flue gas leaves the gas-liquid separation component. The separation component 100 rises further into the coalescing and removal component 400. Unremoved droplets and fine particles in the flue gas adhere to the surface of the coalescing element 402. Once the droplets and fine particles reach a certain size, the drive motor 404 is activated. The droplets and fine particles are then thrown against the inner wall of the desulfurization tower by the centrifugal force generated by the rotation of the central shaft 401, forming a water flow. This water then flows through the overflow pipe 201 into the tray below, achieving a third gas-liquid separation. The rest is the same as in Example 1.

[0053] Example 3

[0054] like Figure 5 , Figure 6 As shown, this embodiment 3 uses the same atomizing nozzle 300 and tray 200 as embodiment 2.

[0055] Unlike Embodiment 2, Embodiment 3 has three overflow pipes 201 on the tray, with the upper end face of the overflow pipes 201 flush with the highest point of the edge of the tray 200. In the gas-liquid separation assembly 100 of this embodiment, the perforated hole 109 is a square hole, and a lower top plate 107 is provided below the upper top plate 103. The lower top plate 107 has an inverted conical structure, and its cone tip is connected to the liquid inlet pipe 108. The lower end of the liquid inlet pipe 108 is located inside the conical section 105. Several through holes 110 are provided on the lower top plate 107, and guide vanes 111 are provided on the side of the through holes 110 facing the upper top plate 103. In the coalescing removal assembly 400 of this embodiment, the driving element of the central shaft 401 is an impeller 405. The impeller 405 is fixed on the central shaft below the coalescing element 402. The impeller 405 can rotate under the action of rising flue gas. The rotation of the impeller 405 can drive the central shaft 401 and drive the coalescing element to rotate, forming centrifugal force.

[0056] The working principle of this embodiment 3 differs from that of embodiment 2 in that: during the spiral ascent of the flue gas in the straight section 101, it impacts the lower top plate 107. Under the influence of inertial force, droplets and fine particles in the flue gas enter the cavity between the upper top plate 103 and the lower top plate 107 through the through-hole 110. Under the action of the guide vane 111, the fine particles entering from the opposite side collide with each other and / or impact the upper top plate 103, forming larger particles that are more easily captured by the droplets. The guide vane 111 not only guides the flue gas but also creates a better flow path. The impact can also prevent the droplets from returning to the straight section 101 through the through hole 110 during the flow of the droplets. The droplets fall under their own gravity and flow along the lower top plate 107 into the liquid inlet pipe 108, and then leave the gas-liquid separation component 100 through the liquid outlet pipe 106, thus removing the droplets and fine particles. The flue gas leaving the gas-liquid separation component 100 enters the coalescing removal component 400. The flue gas drives the impeller 55 to rotate. The rotation of the impeller 55 drives the central shaft 51 and drives the coalescing element to rotate, forming centrifugal force, thereby removing the droplets and fine particles coalescing on the surface. The rest is the same as in Example 2.

[0057] Example 4

[0058] like Figure 7 As shown, the difference between this embodiment 4 and embodiment 3 is that the coalescing removal component 400 in this embodiment simultaneously employs a drive motor 404 and an impeller 405. When the rotational drive element is the drive motor 404 and the impeller 405 is simultaneously installed on the central shaft 401, the drive motor 404 can be periodically turned on and off. When the drive motor 404 is not turned on and the flue gas flows through the impeller 405, the rising flue gas drives the impeller 405 to rotate and drives the central shaft 401 to rotate. At this time, the rotation speed is relatively slow, and droplets and fine particles continuously coalesce on the coalescing element, and the particle size continuously increases. When the particle size increases to a certain extent, the drive motor 404 is turned on, and the rotation speed of the coalescing element 402 increases sharply, generating a large centrifugal force, which removes all droplets and fine particles attached to the coalescing element 402, effectively achieving self-cleaning of the coalescing element 402 and avoiding the consumption of rinsing water.

[0059] Example 5

[0060] This embodiment provides a method for the synergistic removal of mist droplets and fine particulate matter from flue gas using the aforementioned device embodiment, comprising the following steps:

[0061] In step S101, the flue gas after condensation and atomization spraying enters the straight section 101 of the gas-liquid separation component 100 tangentially from the flue gas inlet 102 located at the bottom of the tray.

[0062] In step S102, the flue gas entering the straight section 101 spirals upward, and the fine particles collide and coalesce. The coalesced particles are captured by condensate droplets and separated from the flue gas after centrifugal impact on the cylinder wall, achieving the first gas-liquid separation. When the cylinder wall adopts a double-layer structure, droplets carrying fine particles can pass through the perforated holes 109 on the inner wall and flow along the hollow part between the inner and outer walls to the conical section 105 of the gas-liquid separation component and be discharged through the drain pipe 106. Further, when the flue gas reaches the top of the straight section, the spiraling flue gas can impact the upper top plate, at which time some of the droplets and fine particles in the flue gas can be removed. Preferably, but not limitingly, when an inverted conical lower top plate 107 is provided, the spiraling flue gas can also form a collision in the space enclosed by the upper top plate 103 and the lower top plate 107, which can better remove the droplets and fine particles in the flue gas.

[0063] In step S103, the flue gas flows out at an angle downwards at the flue gas outlet 104 of the gas-liquid separation component 100. The flue gas flowing out from adjacent gas-liquid separation components collides with each other, removing mist droplets and fine particulate matter, thus achieving a second gas-liquid separation.

[0064] In step S104, the flue gas after the collision continues to rise into the space where the coalescing removal component 400 is located. The droplets and fine particles that have coalesced on the coalescing element 402 have increased in size. Under the action of centrifugal force, the droplets and fine particles are thrown towards the wall of the desulfurization tower 10, realizing the third gas-liquid separation. Specifically, under the action of the rising flue gas, the impeller 405 located below the coalescing element 402 drives the central shaft 401 and drives the coalescing element to rotate, forming the centrifugal force; and / or, the drive motor 404 drives the central shaft 401 and drives the coalescing element 402 to rotate, forming centrifugal force.

[0065] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A device for synergistic removal of mist and fine particulate matter from flue gas, characterized in that, The device is arranged in a desulfurization tower and comprises: a plurality of atomizing nozzles fixed on a condensate water pipeline in the desulfurization tower, which are used to atomize and spray the condensate water to form condensate water mist covering a cross section of the desulfurization tower; water vapor in flue gas after cooling and temperature reduction condenses to form fine particles, dust, SO3 aerosol and mist droplets as condensation nuclei, which are condensed and precipitated to form a "water-in-nucleus" structure; a plurality of gas-liquid separation assemblies fixed on the tower tray, which are in a cylindrical structure, the flue gas inlet is arranged below the tower tray and is tangent to the cylinder wall, the atomized and sprayed flue gas enters the flue gas inlet and spirally rises, fine particles collide with each other to produce coalescence, the coalesced particles are captured by the condensate water droplets and separated from the flue gas after centrifugal impact on the cylinder wall, and the flue gas outlet is arranged above the tower tray and is symmetrically and obliquely arranged downward, the flue gas flowing out of adjacent gas-liquid separation assemblies collides with each other to remove the mist droplets and fine particles.

2. The device for flue gas co-removal of droplets and fine particulate matter according to claim 1, characterized in that, The gas-liquid separation assembly comprises: a straight cylinder section, the outer wall of which is sealingly connected with the tower tray, the flue gas inlet is arranged at the lower part of the straight cylinder section, the flue gas outlet is arranged at the upper part of the straight cylinder section, and an upper top plate is arranged at the top of the straight cylinder section; a conical cylinder section, which is arranged below the straight cylinder section and is integrally formed with the straight cylinder section, is used to receive the mist droplets carrying fine particles from the cylinder wall of the straight cylinder section and discharge the collected liquid to below the tower tray.

3. The flue gas co-decontamination device of mist droplets and fine particulate matters according to claim 1, wherein, The cylindrical structure of the gas-liquid separation assembly is provided with a double-layer wall, wherein the inner wall is a hollow wall, and a hollow structure is formed between the inner wall and the outer wall.

4. The flue gas co-removal of droplets and fine particulate matter device of claim 2, wherein, A lower top plate in an inverted conical shape is arranged below the upper top plate, a liquid guide pipe is arranged at the tip of the lower top plate, the liquid guide pipe penetrates through the straight cylinder section and the conical cylinder section, a plurality of through holes are uniformly arranged on the lower top plate, and part of the spirally rising flue gas from the straight cylinder section enters the space enclosed by the upper top plate and the lower top plate through the through holes and collides with each other.

5. The flue gas co-decontamination device of mist droplets and fine particulate matters according to claim 4, wherein, A guide vane extending towards the upper top plate is arranged outside the through hole.

6. The flue gas co-deleting mist and fine particulate matter device according to claim 1, wherein, The device further comprises: a coalescence removal assembly arranged above the gas-liquid separation assembly and receiving the flue gas flowing out of the flue gas outlet of the gas-liquid separation assembly and colliding with each other, which is used to coalesce the mist droplets and fine particles in the flue gas and to throw the mist droplets and fine particles to the wall of the desulfurization tower under the action of centrifugal force after the particle size is increased.

7. The flue gas co-decontamination device of mist droplets and fine particulate matters according to claim 6, wherein, The coalescence removal assembly comprises: a plurality of coalescence elements in a brush-like structure, one end of each coalescence element is fixed on a central shaft, and the plurality of coalescence elements are uniformly and spacedly distributed along the axial and radial directions of the central shaft.

8. The flue gas co-decontamination device of mist droplets and fine particulate matters according to claim 7, wherein, The coalescence removal assembly further comprises an impeller and / or a driving motor; the impeller is arranged below the coalescence elements and is fixed on the central shaft, under the action of the rising flue gas, the impeller drives the central shaft and rotates the coalescence elements; the driving motor is connected with the central shaft and is used to drive the central shaft and rotate the coalescence elements.

9. A method for synergistically removing mist and fine particulate matter from flue gas, characterized by, The device is applied to the following steps: A, the flue gas after condensation, atomization and spraying enters the straight cylinder section of the gas-liquid separation assembly through the flue gas inlet below the tower tray in a tangential direction. B. The flue gas spirally rises into the straight cylinder section, and the fine particles collide with each other to form agglomerates, which are captured by the condensed water droplets and separated from the flue gas after impacting the cylinder wall; C. The flue gas flows downward at the outlet of the gas-liquid separation assembly, and the flue gas from adjacent gas-liquid separation assemblies collide to remove the droplets and fine particles.

10. The method of claim 9, wherein the flue gas is a flue gas from a coal-fired power plant. The cylinder wall in step B has a double-layer structure, and the droplets carrying fine particles flow along the hollow part between the inner wall and the outer wall to the conical cylinder section of the gas-liquid separation assembly and are discharged through the liquid discharge pipe after passing through the hollow holes of the inner wall.

11. The method of claim 9, wherein the flue gas is a flue gas from a coal-fired power plant. The steps between step B and step C include the following step: the spirally rising flue gas impacts the upper top plate to remove the droplets and fine particles in the flue gas.

12. The method of claim 9, wherein the flue gas is a flue gas from a coal-fired power plant. The steps between step B and step C include the following step: the spirally rising flue gas forms a collision in the space enclosed by the upper top plate and the lower top plate to remove the droplets and fine particles in the flue gas.

13. The method of claim 9, wherein the flue gas is a flue gas from a coal-fired power plant. The method further includes the following steps: D. The collided flue gas continues to rise into the space where the coalescence removal assembly is located, and the droplets and fine particles coalesce on the coalescence element, and the droplets and fine particles are thrown to the desulfurization tower wall under the action of centrifugal force.

14. The method of claim 13, wherein the flue gas is a flue gas from a coal-fired power plant. The droplets and fine particles are thrown to the desulfurization tower wall under the action of centrifugal force specifically: Under the action of the rising flue gas, the coalescence element is driven to rotate by the impeller driving central shaft located below the coalescence element, forming the centrifugal force; and / or, The coalescence element is driven to rotate by the central shaft driven by the driving motor, forming the centrifugal force.

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