Rotary gas-solid separation device and method for wet flue gas desulfurization tower

Abstract

The invention relates to a rotary gas-solid separation device and method for a wet flue gas desulfurization tower. The rotary gas-solid separation device comprises a static flow guide part located on the outer layer, a rotary separation part located on the inner layer and a Venturi flow channel structure embedded in the rotary separation part and synchronously rotating with the rotary separation part. The static flow guide component comprises a plurality of curved-surface flow guide blades which are uniformly distributed along the circumferential direction of the inner wall of the desulfurization tower, and the curved-surface flow guide blades convert rising flue gas into rotational flow to enter an inner side rotating area; the rotating separation part comprises a cylindrical rotating body, a plurality of rotational flow blades uniformly mounted on the peripheral surface of the rotating body, and a main shaft fixed with the center of the rotating body; the Venturi flow channel structure comprises a contraction inlet section, an annular expansion outlet section and a throat section communicated with the contraction inlet section and the annular expansion outlet section. According to the invention, inertial separation, centrifugal separation and venturi condensation are combined in three stages, so that particulate matters with different particle sizes can be accurately captured in a grading manner.

Description

Technical Field

[0001] This invention relates to the field of industrial flue gas dust removal and desulfurization technology, and in particular to a rotary gas-solid separation device and method for wet flue gas desulfurization towers. Background Technology

[0002] Currently, wet flue gas desulfurization (WFGD) technology is widely used in coal-fired power plants and industrial boilers. In this process, flue gas enters the desulfurization tower from bottom to top, where it comes into counter-current contact with a limestone-gypsum slurry flowing from top to bottom in a spray layer. Sulfur dioxide is removed through gas-liquid mass transfer reaction. During this process, slurry washing simultaneously removes some particulate matter (PM) from the flue gas. To further improve particulate matter removal efficiency, some desulfurization towers have added enhancement devices such as cyclone separators or tube bundle dust collectors inside the tower.

[0003] Although the combination of the above structures meets the current environmental emission standards to a certain extent, there are still significant shortcomings in actual operation, especially the low efficiency of ultrafine particulate matter capture. Traditional spray scrubbing and conventional demisters are effective for particles and droplets with a diameter greater than 5μm, but for submicron (PM1.0) and micron (PM2.5) ultrafine particles, due to their extremely low inertia and strong ability to follow the airflow, they are difficult to capture effectively, resulting in high dust content in the flue gas and making it difficult to meet the increasingly stringent ultra-low emission requirements. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a rotary gas-solid separation device and method for wet flue gas desulfurization towers.

[0005] In a first aspect, the present invention provides a rotary gas-solid separation device and method for a wet flue gas desulfurization tower, comprising a static flow guiding component located on the outer layer, a rotary separation component located on the inner layer, and a Venturi flow channel structure embedded inside the rotary separation component and rotating synchronously with the rotary separation component.

[0006] The static flow guiding component includes several curved flow guiding blades evenly distributed along the circumference of the inner wall of the desulfurization tower. The curved flow guiding blades convert the rising flue gas into a swirling flow that enters the inner rotating area.

[0007] The rotating separation component includes a cylindrical rotating body, multiple swirl blades uniformly installed on the outer peripheral surface of the rotating body, and a main shaft fixed to the center of the rotating body;

[0008] The Venturi flow channel structure includes a converging inlet section with a gradually decreasing diameter from bottom to top, an annular expanding outlet section located within the rotating body, and a throat section connecting the converging inlet section and the annular expanding outlet section; an air outlet is provided between each pair of adjacent swirl blades, and each air outlet is connected to the annular expanding outlet section.

[0009] Preferably, the inner surface of each curved guide vane includes a first curved surface and a second curved surface, and the first curved surface and the second curved surface are integrally formed to form a continuous curved surface profile structure.

[0010] Preferably, the outer side of each guide vane is fixed to the desulfurization tower, and the bottom of each vane is fixed to the upper porous tray.

[0011] Preferably, the cross-section of the inner surface of each curved guide vane is parabolic, and the radius of curvature at its vertex is... Between 5mm and 20mm.

[0012] Preferably, the number of curved guide vanes is 8-12. The curved guide vanes organize the rising turbulent flue gas into an orderly swirling flow, allowing it to smoothly enter the inner rotating region. Taking advantage of the high inertia of coarse particles (particle size > 10 μm), these particles are captured by impacting the surface of the curved guide vanes when the airflow changes direction, thus removing large particles that are most likely to cause wear and blockage to the spray layer nozzles in advance.

[0013] Preferably, each swirl blade has a proximal connection portion that fits against the outer surface of the rotating body, and a distal guide portion that extends into the external space. Its outline is arc-shaped and twisted circumferentially and bent axially along the rotating body, so that the flue gas generates a stable swirl after being guided by the swirl blade.

[0014] Preferably, six swirl blades are evenly distributed along the circumference of the rotating body.

[0015] Preferably, the installation angle (twist angle) of each swirl blade gradually decreases from the blade root (proximal connector) to the blade tip (distal guide). The installation angle at the blade root... Installation angle at the blade tip Satisfying the relation ,in and These are the tip radius and root radius of the swirl blade, respectively, and empirical coefficients. The value should be between 0.8 and 1.2 to ensure the generation of swirl numbers. The strong swirling flow field. The axial bending of the swirling blades is designed to smoothly transition the airflow from axial velocity to tangential velocity, reducing separation losses.

[0016] The rotating body and swirl blades rotate with the main shaft, applying tangential momentum to the flue gas and forming a powerful forced swirling field. The strong rotational shearing effect greatly enhances the turbulent mixing degree of the gas and liquid phases, thereby increasing the desulfurization reaction rate. Under the action of the strong centrifugal force field, medium and fine particles (particle size 2μm-10μm) are rapidly thrown to the outer region, achieving efficient centrifugal separation.

[0017] Preferably, a funnel-shaped air inlet, wider at the bottom and narrower at the top, is provided at the center of the bottom of the rotating body. A constricted inlet section is formed inside the air inlet, and the narrowest section with the smallest diameter above the constricted inlet section is the throat section.

[0018] The constricted inlet section, throat section, and annular expanding outlet section form a Venturi condenser. Utilizing the relatively low-pressure zone naturally formed in the central region of the rotating body as the swirl blades rotate, this low-pressure zone actively draws in extremely difficult-to-capture ultrafine particles (particle size <2μm) and micro-aerosols from the flue gas into the Venturi channel. The airflow is violently accelerated in the narrow throat section, generating high-intensity turbulence. This causes high-frequency collisions and coalescence between ultrafine particles and micro-droplets, condensing them into larger particle clusters. These larger particle clusters are then ejected at high speed from the outlet back into the outer main swirling flow field, where they are subsequently captured and separated by strong centrifugal force. The Venturi channel structure effectively draws in flue gas under negative pressure and turbulently condenses ultrafine particles within the flue gas.

[0019] Preferably, the spindle speed According to the diameter of the desulfurization tower The minimum particle size required to separate from the target is typically determined by setting the tip linear velocity of the swirl blade. Between 15 m / s and 30 m / s, that is .

[0020] Preferably, the length of the laryngeal segment The aim is to ensure that the residence time of the airflow containing ultrafine particles meets the condensation requirements (typically 5ms-20ms). Equivalent diameter of the throat segment 1.0-3.0 times, that is .

[0021] Preferably, the rotary gas-solid separation device is installed inside the desulfurization tower and located below the spray layer and above the flue gas inlet.

[0022] Preferably, a slurry pool is provided at the bottom of the desulfurization tower.

[0023] Preferably, a lower porous tray is installed below the rotary gas-solid separator and above the flue gas inlet. The lower porous tray ensures uniform flow of the flue gas entering the desulfurization tower.

[0024] Preferably, the upper end of the main shaft extends to the flue gas outlet at the top of the desulfurization tower and is connected to the drive mechanism.

[0025] Preferably, the drive mechanism includes a drive motor installed outside the desulfurization tower, and the output shaft of the drive motor is connected to the main shaft through a steering gear.

[0026] A second aspect of the present invention provides a method for separating gas and solid using the above-described rotary gas-solid separation device, comprising the following steps:

[0027] (1) When the main shaft is started to rotate, the coarse particles in the flue gas are captured by the inertial interception of the curved guide vanes during the flue gas rise.

[0028] (2) Fine particles are separated by centrifugal force under the strong centrifugal swirling field of the swirl blades;

[0029] (3) After the ultrafine particles are drawn in, condensed and thickened by the Venturi channel structure, they are then separated by centrifugal swirling flow field.

[0030] The beneficial effects of this invention are as follows:

[0031] 1. This invention ingeniously utilizes the energy (centrifugal force field and central negative pressure field) generated during the movement of the rotating separation component, combining inertial separation, centrifugal separation, and Venturi condensation in a three-stage process to achieve precise and graded collection of particles of different sizes, particularly significantly improving the overall removal efficiency of PM2.5 ultrafine particles. It creatively utilizes the central negative pressure generated by the rotating separation component itself to drive the Venturi condensation process, eliminating the need for additional high-pressure fans or other external energy sources, achieving low-cost active condensation with low energy consumption and high efficiency. The static flow guiding component works in conjunction with the rotating separation component to form a stable and enhanced swirling field, further enhancing the centrifugal separation effect.

[0032] 2. Particulate matter is efficiently removed below the spray layer, reducing the burden on subsequent spray washing. Cleaner flue gas (with low particulate matter content) enters the spray zone, which on the one hand reduces the interference of particulate matter on the sulfur dioxide absorption process, improves desulfurization efficiency, reduces the number and density of spray layers, and eliminates the need for subsequent tube bundle dust collectors, thus reducing the complexity of the equipment. On the other hand, it avoids nozzle blockage caused by particulate matter deposition and scaling at the spray layer nozzles, as well as the aggravated wear of the nozzles by dust-laden airflow, thus reducing the maintenance cost of the spray layer.

[0033] 3. The static flow guiding component, the rotating separation component and the Venturi flow channel structure are cleverly integrated into one unit and placed in the original space below the spray layer. This eliminates the need to occupy a large amount of tower height or width. Compared with adding multiple layers of spray or large tube bundle dust collectors, the structure is more compact and has a higher space utilization rate.

[0034] 4. The unique "sandwich" nested structure of the static flow guiding component, rotating separation component, and Venturi flow channel integrates pre-separation, swirl separation, and condensation enhancement functions, greatly saving tower space and investment costs. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the present invention installed inside the desulfurization tower;

[0036] Figure 2 This is a cross-sectional structural diagram of the present invention and the desulfurization tower;

[0037] Figure 3 This is a schematic diagram of the structure of the rotary gas-solid separation device of the present invention;

[0038] Figure 4 This is a schematic diagram of the structure of the rotating separation component of the present invention;

[0039] Figure 5 This is a cross-sectional view of the rotating separation component of the present invention;

[0040] As shown in the figure:

[0041] 1. Desulfurization tower; 2. Curved guide vanes; 3. Upper porous tray; 4. Rotating body; 5. Swirl vanes; 6. Main shaft; 7. Contraction inlet section; 8. Annular expansion outlet section; 9. Throat section; 10. Gas outlet; 11. Spray layer; 12. Flue gas inlet; 13. Slurry pool; 14. Diverter; 15. Lower porous tray; 16. Flue gas outlet; 17. Drive motor. Detailed Implementation

[0042] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0043] like Figure 1-5 As shown, the present invention includes a static flow guiding component located on the outer layer, a rotating separation component located on the inner layer, and a Venturi flow channel structure embedded inside the rotating separation component and rotating synchronously with the rotating separation component.

[0044] The static flow guiding component includes several curved flow guiding blades 2 evenly distributed circumferentially along the inner wall of the desulfurization tower 1. The curved flow guiding blades 2 convert the rising flue gas into a swirling flow that enters the inner rotating region. The inner surface of each curved flow guiding blade 2 includes a first curved surface and a second curved surface, which are integrally formed to create a continuous curved surface profile structure. The outer side of each flow guiding blade is fixed to the desulfurization tower 1, and the bottom of each blade is fixed to the upper porous tray 3.

[0045] In this embodiment, the cross-section of the inner surface of each curved guide vane 2 is parabolic, and the radius of curvature at the vertex of each curved guide vane 2 is... Based on the target minimum particle size for removing coarse particles (e.g., 10μm) for design to meet the requirements ,in Particle density, The inlet airflow velocity is the velocity at the blade inlet. For flue gas viscosity, This is an empirical coefficient, typically ranging from 0.05 to 0.2. However, considering engineering manufacturing and wear resistance, in actual design... The value is between 5mm and 20mm.

[0046] The number of curved guide vanes 2 is 8-12. In this embodiment, the number of curved guide vanes 2 is 12. The curved guide vanes 2 organize the rising turbulent flue gas into an orderly swirling flow, allowing it to smoothly enter the inner rotating region. Taking advantage of the high inertia of coarse particles (particle size > 10 μm), they are captured by impacting the surface of the curved guide vanes 2 when the airflow changes direction, thus removing large particles that are most likely to cause wear and blockage to the nozzles of the spray layer 11 in advance.

[0047] The rotating separation component includes a cylindrical rotating body 4, multiple swirl blades 5 uniformly installed on the outer circumferential surface of the rotating body 4, and a main shaft 6 fixed to the center of the rotating body 4. Each swirl blade 5 has a proximal connecting part that fits against the outer surface of the rotating body 4, and a distal guiding part that extends into the external space. Its outline is arc-shaped and twisted circumferentially and bent axially along the rotating body 4, so that the flue gas generates a stable swirl after being guided by the swirl blades 5.

[0048] In this embodiment, six swirl blades 5 are evenly distributed around the rotating body 4. The installation angle (twist angle) of each swirl blade 5 gradually decreases from the blade root (proximal connection) to the blade tip (distal guide). The installation angle at the blade root... Installation angle at the blade tip Satisfying the relation ,in and These are the tip radius and root radius of the swirl blade, respectively, and empirical coefficients. The value should be between 0.8 and 1.2 to ensure the generation of swirl numbers. The strong swirling flow field. The axial bending of the swirling blades is designed to smoothly transition the airflow from axial velocity to tangential velocity, reducing separation losses.

[0049] The rotating body 4 and the swirl blades 5 rotate with the main shaft 6, applying tangential momentum to the flue gas and forming a powerful forced swirling field. The strong rotational shearing effect greatly enhances the turbulent mixing degree of the gas and liquid phases, thereby increasing the desulfurization reaction rate. Under the action of the strong centrifugal force field, medium and fine particles (particle size 2μm-10μm) are rapidly thrown to the outer region, achieving efficient centrifugal separation.

[0050] The Venturi flow channel structure includes a converging inlet section 7 with a gradually decreasing diameter from bottom to top, an annular expanding outlet section 8 located within the rotating body 4, and a throat section 9 connecting the converging inlet section 7 and the annular expanding outlet section 8. An air outlet 10 is provided between each pair of adjacent swirl blades 5, and each air outlet 10 communicates with the annular expanding outlet section 8. A trumpet-shaped air inlet, wider at the bottom and narrower at the top, is provided at the center of the bottom of the rotating body 4. The converging inlet section 7 is formed within the air inlet, and the narrowest section above the converging inlet section 7, with the smallest diameter, is the throat section 9.

[0051] The constricted inlet section 7, throat section 9, and annular expansion outlet section 8 form a Venturi condenser. Utilizing the relatively low-pressure zone naturally formed in the central region of the rotating body 4 as the swirl blades 5 rotate, this low-pressure zone actively draws in extremely difficult-to-capture ultrafine particles (particle size <2μm) and micro-aerosols from the flue gas into the Venturi channel. The airflow is violently accelerated in the narrow throat section 9, generating high-intensity turbulence. This causes high-frequency collisions and coalescence between ultrafine particles and micro-droplets, condensing them into larger particle clusters. These larger particle clusters are then ejected at high speed from the outlet 10 back into the outer main swirling flow field, where they are immediately captured and separated by strong centrifugal force. The Venturi channel structure effectively draws in flue gas under negative pressure and turbulently condenses ultrafine particles within the flue gas.

[0052] Spindle speed According to the diameter of the desulfurization tower The minimum particle size required to separate from the target is typically determined by setting the tip linear velocity of the swirl blade. Between 15 m / s and 30 m / s, that is .

[0053] Length of larynx segment 9 The aim is to ensure that the residence time of the airflow containing ultrafine particles meets the condensation requirements (typically 5ms-20ms). The equivalent diameter of the throat segment is 9. 1.0-3.0 times, that is .

[0054] This device is installed inside the desulfurization tower 1, below the spray layer 11 and above the flue gas inlet 12. A slurry pool 13 is provided at the bottom of the desulfurization tower 1. A lower porous tray 15 is installed below this device and above the flue gas inlet 12 to distribute the flue gas entering the desulfurization tower 1 evenly. The upper end of the main shaft 6 extends to the flue gas outlet 16 at the top of the desulfurization tower 1 and is connected to the drive mechanism. The drive mechanism includes a drive motor 17 installed outside the desulfurization tower 1, and the output shaft of the drive motor 17 is connected to the main shaft 6 through a diverter 14.

[0055] The method for separating gas and solid using the above-described rotary gas-solid separation device includes the following steps:

[0056] (1) Start the main shaft 6 to rotate. After the flue gas enters the desulfurization tower 1 from the flue gas inlet 12, it continues to rise after passing through the lower porous tray 15 and the upper porous tray 3 for equal flow. During the rise of the flue gas, the coarse particles in the flue gas are inertially intercepted and captured by the curved guide vanes 2.

[0057] (2) Medium and fine particles are separated by centrifugal force under the strong centrifugal swirling field of the swirl blade 5;

[0058] (3) After the ultrafine particles are drawn in, condensed and thickened by the Venturi channel structure, they are then separated by centrifugal swirling flow field.

[0059] This invention enables precise capture of particulate matter in flue gas according to its size classification. The purified flue gas continues to rise into the spray layer 11, where the captured particulate matter mixes with the spray slurry and falls into the slurry pool 13.

[0060] This invention ingeniously utilizes the energy (centrifugal force field and central negative pressure field) generated during the movement of the rotating separation component, combining inertial separation, centrifugal separation, and Venturi agglomeration in a three-stage process to achieve precise and graded collection of particles of different sizes, with a significant improvement in the overall removal efficiency of PM2.5 ultrafine particles. It creatively uses the central negative pressure generated by the rotating separation component itself to drive the Venturi agglomeration process, eliminating the need for additional high-pressure fans or other external energy sources, thus achieving low-cost active agglomeration with low energy consumption.

[0061] Of course, the above description is not limited to the examples above. Technical features not described in this invention can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solutions of this invention and are not intended to limit this invention. This invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention do not depart from the spirit of this invention and should also fall within the scope of protection of the claims of this invention.

Claims

1. A rotary gas-solid separation device for a wet flue gas desulfurization tower, characterized in that: It includes a static flow guide component located on the outer layer, a rotating separation component located on the inner layer, and a Venturi flow channel structure embedded inside the rotating separation component and rotating synchronously with the rotating separation component; The static flow guiding component includes several curved flow guiding blades evenly distributed along the circumference of the inner wall of the desulfurization tower. The curved flow guiding blades convert the rising flue gas into a swirling flow that enters the inner rotating area. The rotating separation component includes a cylindrical rotating body, multiple swirl blades uniformly installed on the outer peripheral surface of the rotating body, and a main shaft fixed to the center of the rotating body; The Venturi flow channel structure includes a converging inlet section with a gradually decreasing diameter from bottom to top, an annular expanding outlet section located within the rotating body, and a throat section connecting the converging inlet section and the annular expanding outlet section; an air outlet is provided between each pair of adjacent swirl blades, and each air outlet is connected to the annular expanding outlet section.

2. The rotary gas-solid separation device for a wet flue gas desulfurization tower according to claim 1, characterized in that: Each curved guide vane has a first curved surface and a second curved surface on its inner side. The first curved surface and the second curved surface are integrally formed to form a continuous curved surface profile structure.

3. A rotary gas-solid separation device for a wet flue gas desulfurization tower according to claim 2, characterized in that: The outer side of each guide vane is fixed to the desulfurization tower, and the bottom of each vane is fixed to the upper porous tray.

4. A rotary gas-solid separation device for a wet flue gas desulfurization tower according to claim 1, characterized in that: Each swirl blade has a proximal connection that fits against the outer surface of the rotating body, and a distal guide that extends into the external space. Its outline is arc-shaped and twisted circumferentially and bent axially along the rotating body, so that the flue gas generates a stable swirl after being guided by the swirl blade.

5. A rotary gas-solid separation device for a wet flue gas desulfurization tower according to claim 1, characterized in that: A horn-shaped air inlet, wider at the bottom and narrower at the top, is set at the center of the bottom of the rotating body. A constricted inlet section is formed inside the air inlet, and the narrowest section with the smallest diameter above the constricted inlet section is the throat section.

6. A rotary gas-solid separation device for a wet flue gas desulfurization tower according to claim 1, characterized in that: The rotating gas-solid separation device is installed inside the desulfurization tower and is located below the spray layer and above the flue gas inlet.

7. A rotary gas-solid separation device for a wet flue gas desulfurization tower according to claim 1, characterized in that: A perforated tray is installed below the rotary gas-solid separator and above the flue gas inlet.

8. A rotary gas-solid separation device for a wet flue gas desulfurization tower according to claim 1, characterized in that: The upper end of the main shaft extends to the flue gas outlet at the top of the desulfurization tower and is connected to the drive mechanism.

9. A method for separating gas and solid using the rotary gas-solid separator according to any one of claims 1-8, characterized in that, Includes the following steps: (1) When the main shaft is started to rotate, the coarse particles in the flue gas are captured by the inertial interception of the curved guide vanes during the flue gas rise. (2) Fine particles are separated by centrifugal force under the strong centrifugal swirling field of the swirl blades; (3) After the ultrafine particles are drawn in, condensed and thickened by the Venturi channel structure, they are then separated by centrifugal swirling flow field.

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