A desulfurization device and method based on zoned flow guidance and liquid film redistribution

Abstract

This invention relates to a desulfurization device based on partitioned flow guidance and liquid film redistribution. The desulfurization device includes a desulfurization tower, a compartmented pressure equalization guiding mechanism installed inside the desulfurization tower and located above the flue gas inlet, and a slurry redistribution mechanism. The compartmented pressure equalization guiding mechanism includes an inner ring and an outer ring arranged concentrically from the inside to the outside. The inner ring and the outer ring are fixedly connected by several radially distributed partitions along the circumference. The radial partitions divide the annular area between the inner ring and the outer ring into multiple independent guiding partitions distributed along the circumference. Each guiding partition is equipped with a flow guide window with an adjustable opening. The slurry redistribution mechanism includes a flow guide cylinder and a liquid receiving hopper fixed around the upper outer side of the flow guide cylinder. The liquid receiving hopper has a funnel-shaped structure that is wider at the top and narrower at the bottom. This invention significantly improves the desulfurization efficiency and demisting efficiency through the cooperation of the compartmented pressure equalization guiding mechanism and the slurry redistribution mechanism.

Description

Technical Field

[0001] This invention relates to the field of wet flue gas desulfurization technology, and in particular to a desulfurization device and method based on zoned flow guidance and liquid film redistribution. Background Technology

[0002] Wet flue gas desulfurization (FGD) is currently the mainstream technology for controlling sulfur dioxide emissions in coal-fired power plants and industrial kilns. A typical FGD system includes a slurry pool at the bottom, a spray absorption zone in the middle, and a demister at the top. Flue gas enters laterally from the bottom or middle of the tower, comes into countercurrent contact with the spray slurry to complete the desulfurization reaction, and is then discharged after the demister removes any carried droplets.

[0003] In practical engineering applications, due to limitations in site space and flue layout, the inlet flue of desulfurization towers often has sharp bends or diameter changes, which easily leads to severe flow deviation of the flue gas entering the tower. That is, the flue gas velocity is high on one side of the tower cross-section, while the velocity is low on the other side, or even backflow occurs. This non-uniform flow field easily causes the following problems: insufficient residence time of flue gas in the high-velocity zone, inadequate gas-liquid mass transfer, and decreased desulfurization efficiency; the low-velocity zone is prone to forming spray dead zones, leading to increased risk of slurry accumulation and scaling inside the tower; at the same time, the large number of droplets carried by the deviation will concentrate and impact the local area of ​​the demister at the top of the tower, causing flooding and secondary entrainment, making it difficult to meet the increasingly stringent ultra-low emission requirements.

[0004] Furthermore, after completing gas-liquid contact, the slurry sprayed from the spray layer mostly falls back to the bottom of the tower in the form of discrete droplets, failing to form a continuous and stable gas-liquid contact interface within the tower, resulting in a waste of slurry kinetic energy and washing potential. Although existing technologies use flow equalization plates to attempt to improve the flow field, their adjustment capabilities are limited, and there is a lack of effective means to actively convert the falling slurry into a secondary washing medium. Therefore, there is an urgent need for an integrated device that can synergistically achieve inlet zone pressure equalization, flow field guidance, and spray slurry regeneration to improve the overall operational efficiency of the desulfurization tower. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a desulfurization device and method based on zoned flow guidance and liquid film redistribution.

[0006] In a first aspect, the present invention provides a desulfurization device based on partitioned flow guidance and liquid film redistribution, comprising a desulfurization tower, a compartmentalized pressure equalization guiding mechanism and a slurry redistribution mechanism installed inside the desulfurization tower and located above the flue gas inlet;

[0007] The compartment pressure equalization guide mechanism includes an inner ring and an outer ring arranged concentrically from the inside to the outside. The inner ring and the outer ring are fixedly connected by a number of radially distributed partitions along the circumference. The radial partitions divide the annular area between the inner ring and the outer ring into multiple independent guide zones distributed along the circumference. Each guide zone is equipped with a guide window with an adjustable opening.

[0008] The slurry redistribution mechanism includes a guide cylinder and a receiving hopper fixed around the upper outer side of the guide cylinder; the guide cylinder is a cylindrical structure with openings at both the upper and lower ends, and the lower end of the guide cylinder is fixedly connected and communicates with the inner side of the inner ring; the receiving hopper is a funnel-shaped structure that is wider at the top and narrower at the bottom, with its upper opening located outside the guide cylinder and its lower opening penetrating the cylinder wall and extending into the interior of the guide cylinder.

[0009] Preferably, each guide window includes several blades evenly distributed circumferentially and arranged radially. The width of the blades gradually increases from the inside to the outside. The two ends of each blade are rotatably connected to the inner and outer rings via pivots, allowing the blades to deflect at an angle around the pivot. By independently adjusting the opening of each guide window, different flow resistance distributions can be established circumferentially, thereby achieving zoned pressure equalization and flow direction correction for the inlet deflected flue gas.

[0010] Preferably, a gear is fixedly sleeved on the outer end shaft of each blade, and an arc rack is slidably installed on the inner wall of the desulfurization tower. The gear at the outer end of each blade meshes with the arc rack, and the shaft of one blade is fixedly connected to the output end of an electric actuator.

[0011] Preferably, a circumferential sliding cavity is fixed on the inner wall of the desulfurization tower, and the arc-shaped rack is installed in the sliding cavity and can slide horizontally along it.

[0012] Preferably, the electric actuator is an electric motor. When it is necessary to adjust the opening of the guide window, the electric actuator drives the shaft of the blade connected to it to rotate. This shaft drives the gear on it to rotate, which in turn drives the arc rack to slide horizontally along the inner wall of the desulfurization tower. The movement of the arc rack, through the meshing relationship between the gear and the arc rack, drives the shafts of all other blades to rotate synchronously, thereby realizing the linkage adjustment of the angle of each blade, and thus changing the flow area of ​​the guide zone.

[0013] Preferably, a flue gas detection mechanism for detecting the flue gas velocity distribution is installed above the flue gas inlet of the desulfurization tower, and the flue gas detection mechanism is connected to the control unit circuit.

[0014] Preferably, the flue gas detection mechanism is an existing pitot tube. The flue gas detection mechanism detects the flue gas velocity distribution of the flue gas cross section in real time and transmits the signal to the control unit. The control unit is an existing controller. The controller generates control commands based on the signal data and drives the electric actuators in the corresponding areas to complete the flue gas deviation correction.

[0015] Preferably, a flow equalization plate is installed inside the desulfurization tower above the flue gas inlet and below the compartment pressure equalization guide mechanism. The flow equalization plate is a circular plate with several evenly distributed through holes. The flow equalization plate provides initial flow equalization for the flue gas.

[0016] Preferably, the bottom surface of the receiving hopper is fixedly connected to the wall of the guide cylinder, and a liquid passage hole is provided on the wall of the guide cylinder at the fixed point. The slurry flows from the bottom of the receiving hopper into the guide cylinder through the liquid passage hole.

[0017] Preferably, an outlet hole is provided on the bottom side wall of the liquid receiving hopper located outside the guide tube.

[0018] Preferably, a spray layer is installed inside the desulfurization tower located above the receiving hopper. After the slurry sprayed from the spray layer comes into contact with the rising flue gas, part of the slurry falls back into the receiving hopper. The slurry falling into the receiving hopper is split. One stream of slurry flows out through the outlet hole at the bottom of the receiving hopper and flows downward along the outer surface of the guide tube, forming a continuous and stable outer liquid film on the outer wall of the guide tube. The other stream of slurry flows downward through the opening at the lower end of the receiving hopper, forming an inner liquid curtain inside the guide tube. The flue gas on the side wall of the desulfurization tower continues to rise after being pressure-equalized and corrected by the various guide zones of the compartment pressure equalization and guiding mechanism, and comes into contact with the outer liquid film on the outer wall of the guide tube. The mainstream flue gas in the middle of the desulfurization tower enters the interior of the guide tube through the inner ring and comes into contact with the inner liquid curtain inside the guide tube.

[0019] Preferably, a baffle demister is installed inside the desulfurization tower above the spray layer.

[0020] In a second aspect, the present invention provides a desulfurization method using the above-mentioned desulfurization device, comprising the following steps: (1) after the sulfur-containing flue gas enters the desulfurization tower, the flue gas on the side wall is corrected by the compartment pressure equalization guide mechanism and flows upward, and comes into countercurrent contact with the slurry sprayed from the upper spray layer to carry out the desulfurization reaction, and comes into contact with the outer liquid film on the outer wall of the guide tube for secondary washing.

[0021] (2) The mainstream flue gas in the middle enters the guide tube after passing through the inner ring, and comes into countercurrent contact with the slurry sprayed from the upper spray layer to carry out desulfurization reaction, and comes into contact with the inner liquid curtain at high speed shear and disturbance.

[0022] (3) The flue gas continues to rise after being washed and is discharged from the flue gas outlet at the top of the desulfurization tower after being demisted.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. Through multiple independent guide zones and adjustable flow guide windows in the compartment pressure equalization guide mechanism, the circumferential resistance can be adjusted differently according to the flue gas inlet flow deviation, effectively eliminating the flow velocity deviation of the tower section, correcting the turbulent flow field into a uniform upward flow field, solving the problem of insufficient adjustment capacity of traditional flow equalization plates, and realizing precise zonal control and flow field pressure equalization of the inlet flue gas.

[0025] 2. The receiving hopper of the slurry redistribution mechanism actively diverts part of the originally disordered slurry, forming an inner liquid curtain on the inner wall of the guide tube, which enhances the high-intensity mass transfer in the central mainstream zone; and forms an outer liquid film on the outer wall of the guide tube, providing a continuously renewed washing interface for the flue gas on the side walls, effectively capturing fine particles.

[0026] 3. The compartmentalized pressure equalization guiding mechanism ensures the uniformity of airflow distribution, providing an ideal flow field environment for gas-liquid contact. The top-narrow and bottom-wide guide tube structure further accelerates the flue gas velocity inside the tube, maximizing the turbulent contact between the inner liquid curtain and the high-speed flue gas. At the same time, the outer liquid film specifically addresses the sidewall airflow, complementing the inner liquid curtain and eliminating mass transfer dead zones. The inner liquid curtain, outer liquid film, upper spray layer, and baffle demister form a stepped purification system, significantly reducing the droplet load at the demister inlet. The coupling and functional synergy of the above structures greatly improve the overall desulfurization and demisting efficiency of the system. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of the compartment pressure equalization guiding mechanism and the slurry redistribution mechanism of the present invention;

[0029] Figure 3 This is a schematic diagram of the longitudinally cut structure of the compartment pressure equalization guiding mechanism and the slurry redistribution mechanism of the present invention;

[0030] Figure 4 This is a partial structural schematic diagram of the compartmentalized pressure equalization guiding mechanism of the present invention;

[0031] Figure 5 This is a schematic diagram of the structure of one blade of the compartment pressure equalization guide mechanism of the present invention;

[0032] Figure 6 This is a schematic diagram of the flow equalization plate of the present invention;

[0033] As shown in the figure:

[0034] 1. Desulfurization tower; 2. Flue gas inlet; 3. Compartmentalized pressure equalization and guiding mechanism; 4. Slurry redistribution mechanism; 5. Flow equalization plate; 6. Spray layer; 7. Baffle plate demister.

[0035] 31. Inner ring; 32. Outer ring; 33. Radial partition; 34. Blade; 35. Gear; 36. Circular arc rack; 37. Electric actuator; 38. Slide cavity.

[0036] 41. Flow guide tube, 42. Liquid receiving hopper, 43. Liquid passage hole, 44. Liquid outlet hole. Detailed Implementation

[0037] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0038] like Figure 1-6 As shown, the present invention includes a desulfurization tower 1, a compartmentalized pressure equalization guiding mechanism 3 installed inside the desulfurization tower 1 and located above the flue gas inlet 2, and a slurry redistribution mechanism 4.

[0039] The compartmentalized pressure equalization guiding mechanism 3 includes an inner ring 31 and an outer ring 32 arranged concentrically from the inside to the outside. The inner ring 31 and the outer ring 32 are fixedly connected by several radially distributed partitions 33. The radial partitions 33 divide the annular area between the inner ring 31 and the outer ring 32 into multiple independent guiding zones distributed along the circumference. Each guiding zone is equipped with an adjustable flow guide window. By independently adjusting the opening of each flow guide window, different flow resistance distributions can be established in the circumferential direction, thereby performing compartmentalized pressure equalization and flow direction correction for the inlet deviated flue gas.

[0040] Each guide window includes several blades 34 evenly distributed circumferentially and arranged radially. The width of the blades 34 gradually increases from the inside to the outside, forming a fan-shaped or trapezoidal structure to adapt to the fan-shaped geometry of the guide zone. Each blade 34 is rotatably connected to the inner ring 31 and outer ring 32 via a rotating shaft, allowing the blade 34 to deflect angularly around the rotating shaft. A gear 35 is fixedly fitted onto the rotating shaft at the outer end of each blade 34. An arc-shaped rack 36 is slidably mounted on the inner wall of the desulfurization tower 1, and the gear 35 at the outer end of each blade 34 meshes with the arc-shaped rack 36. The rotating shaft of one blade 34 is fixedly connected to the output end of an electric actuator 37. In this embodiment, the electric actuator 37 is an electric motor. When the opening of the guide window needs to be adjusted, the electric actuator 37 drives the rotating shaft of the blade 34 connected to it to rotate. This rotating shaft drives the gear 35 on it to rotate, thereby driving the arc-shaped rack 36 to slide horizontally along the inner wall of the desulfurization tower 1. The movement of the arc rack 36, through the meshing relationship between the gear 35 and the arc rack 36, drives the rotating shafts of all other blades 34 to rotate synchronously, thereby achieving the linkage adjustment of the angle of each blade 34 and thus changing the flow area of ​​the guide zone. A circumferential sliding cavity 38 is fixed on the inner wall of the desulfurization tower 1, and the arc rack 36 is installed in the sliding cavity 38 and can slide horizontally along it.

[0041] By adjusting the opening and closing angles of the blades 34 in different guide zones, the flow area of ​​that region can be locally changed. A flue gas detection mechanism for detecting the flue gas velocity distribution is installed above the flue gas inlet 2 of the desulfurization tower 1. The flue gas detection mechanism is electrically connected to the control unit. In this embodiment, the flue gas detection mechanism is an existing pitot tube. The flue gas detection mechanism detects the flue gas velocity distribution of the flue gas cross section in real time and transmits the signal to the control unit. The control unit is an existing controller. The controller generates control commands based on the signal data and drives the electric actuator 37 of the corresponding region to operate, thereby completing the flue gas deviation correction.

[0042] In this embodiment, a flow equalization plate 5 is installed inside the desulfurization tower 1 above the flue gas inlet 2 and below the compartment pressure equalization guide mechanism 3. The flow equalization plate 5 is a circular plate with several evenly distributed through holes. The flow equalization plate 5 provides initial flow equalization for the flue gas.

[0043] The slurry redistribution mechanism 4 includes a guide cylinder 41 and a receiving hopper 42 fixed around the upper outer side of the guide cylinder 41. The guide cylinder 41 is a cylindrical structure with openings at both the top and bottom. The lower end of the guide cylinder 41 is fixedly connected and communicates with the inner side of the inner ring 31, so that the mainstream flue gas in the middle of the desulfurization tower 1 enters the interior of the guide cylinder 41 through the inner ring 31 and flows upward.

[0044] The receiving hopper 42 has a funnel-shaped structure that is wider at the top and narrower at the bottom. Its upper opening is located outside the guide cylinder 41, and its lower opening penetrates the cylinder wall of the guide cylinder 41 and extends into the interior of the guide cylinder 41. The bottom surface of the receiving hopper 42 is fixedly connected to the cylinder wall of the guide cylinder 41. A liquid passage hole 43 is provided on the cylinder wall of the guide cylinder 41 at the fixed point, and the slurry flows from the bottom of the receiving hopper 42 into the guide cylinder 41 through the liquid passage hole 43. A liquid outlet hole 44 is provided on the bottom side wall of the receiving hopper 42 located outside the guide cylinder 41.

[0045] A spray layer 6 is installed inside the desulfurization tower 1 located above the liquid receiving hopper 42. After the slurry sprayed from the spray layer 6 comes into contact with the rising flue gas, part of the slurry falls back into the liquid receiving hopper 42. The slurry falling into the liquid receiving hopper 42 is split. One stream of slurry flows out through the liquid outlet 44 at the bottom of the liquid receiving hopper 42 and flows downward along the outer surface of the guide tube 41, forming a continuous and stable outer liquid film on the outer wall of the guide tube 41. The other stream of slurry flows downward through the lower opening of the liquid receiving hopper 42, forming an inner liquid curtain inside the guide tube 41.

[0046] The flue gas on the side wall of the desulfurization tower 1 continues to rise after being pressure-equalized and corrected by the various guide zones of the compartment pressure equalization and guiding mechanism 3, and comes into contact with the outer liquid film on the outer wall of the guide tube 41; the mainstream flue gas in the middle of the desulfurization tower 1 enters the interior of the guide tube 41 through the inner ring 31 and comes into contact with the inner liquid curtain inside the guide tube 41.

[0047] The compartmentalized pressure equalization and guiding mechanism 3 first divides the flue gas in different areas of the tower cross-section into zones, eliminating flow field deviations. Then, the corrected sidewall flue gas is guided to the outer wall of the guide tube 41 to flush the outer liquid film, transforming the sidewall area into a highly efficient secondary scrubbing zone, effectively capturing entrained fine particles. Simultaneously, the mainstream flue gas is introduced into the guide tube 41, which is narrower at the top and wider at the bottom. The structure of the guide tube 41 increases the flue gas velocity, and the high-speed flue gas undergoes strong shearing and mixing with the counter-flowing inner liquid curtain, greatly enhancing the turbulent mass transfer intensity in the central mainstream zone. The compartmentalized pressure equalization and guiding mechanism 3 and the slurry redistribution mechanism 4 have clearly defined functions and support each other, forming a tiered purification system of zoned pressure equalization and dual-liquid-film regeneration.

[0048] A baffle demister 7 is installed inside the desulfurization tower 1 above the spray layer 6. The baffle demister 7 is used for the final demisting and dehydration of the flue gas after double washing. The baffle demister 7 adopts existing technology, and its specific structure and working principle will not be described in detail here. After being washed by the spray layer 6, the outer liquid film and the inner liquid curtain, the flue gas continues to rise into the baffle demister 7. After removing the large droplets, it is discharged from the top of the tower, and the falling slurry is finally collected in the slurry pool at the bottom of the tower for recycling.

[0049] The desulfurization method using the above-mentioned desulfurization device includes the following steps:

[0050] (1) After the sulfur-containing flue gas enters the desulfurization tower 1, the flue gas on the side wall is corrected by the compartment pressure equalization guide mechanism 3 and flows upward. It comes into countercurrent contact with the slurry sprayed from the upper spray layer 6 to carry out the desulfurization reaction, and comes into contact with the outer liquid film on the outer wall of the guide tube 41 for secondary washing.

[0051] (2) The mainstream flue gas in the middle enters the guide tube 41 after passing through the inner ring 31, and comes into countercurrent contact with the slurry sprayed from the upper spray layer 6 to carry out desulfurization reaction, and comes into contact with the inner liquid curtain through high-speed shearing and disturbance.

[0052] (3) The flue gas continues to rise after being washed and is discharged from the flue gas outlet at the top of the desulfurization tower 1 after being demisted.

[0053] 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 desulphurization device based on zoned flow diversion and liquid film redistribution, characterized in that: It includes a desulfurization tower, a compartmentalized pressure equalization and guiding mechanism installed inside the desulfurization tower and located above the flue gas inlet, and a slurry redistribution mechanism; The compartment pressure equalization guide mechanism includes an inner ring and an outer ring arranged concentrically from the inside to the outside. The inner ring and the outer ring are fixedly connected by a number of radially distributed partitions along the circumference. The radial partitions divide the annular area between the inner ring and the outer ring into multiple independent guide zones distributed along the circumference. Each guide zone is equipped with a guide window with an adjustable opening. The slurry redistribution mechanism includes a guide cylinder and a receiving hopper fixed around the upper outer side of the guide cylinder; the guide cylinder is a cylindrical structure with openings at both the upper and lower ends, and the lower end of the guide cylinder is fixedly connected and communicates with the inner side of the inner ring; the receiving hopper is a funnel-shaped structure that is wider at the top and narrower at the bottom, with its upper opening located outside the guide cylinder and its lower opening penetrating the cylinder wall and extending into the interior of the guide cylinder.

2. The desulfurization device based on zoned flow guidance and liquid film redistribution according to claim 1, characterized in that: Each guide window includes several blades evenly distributed circumferentially and arranged radially. The width of the blades gradually increases from the inside to the outside. The two ends of each blade are rotatably connected to the inner ring and the outer ring through a rotating shaft, so that the blade can deflect at an angle around the rotating shaft.

3. A desulfurization device based on zoned flow guidance and liquid film redistribution according to claim 2, characterized in that: A gear is fixedly fitted on the outer end shaft of each blade, and an arc rack is slidably installed on the inner wall of the desulfurization tower. The gear at the outer end of each blade meshes with the arc rack, and the shaft of one blade is fixedly connected to the output end of an electric actuator.

4. A desulfurization device based on zoned flow guidance and liquid film redistribution according to claim 3, characterized in that: A circumferential sliding cavity is fixed on the inner wall of the desulfurization tower, and the arc-shaped rack is installed in the sliding cavity and can slide horizontally along it.

5. A desulfurization device based on zoned flow guidance and liquid film redistribution according to claim 1, characterized in that: The bottom surface of the receiving hopper is fixedly connected to the wall of the guide tube, and a liquid passage hole is provided on the wall of the guide tube at the fixed point.

6. A desulfurization device based on zoned flow guidance and liquid film redistribution according to claim 5, characterized in that: An outlet hole is provided on the bottom side wall of the receiving hopper located outside the guide tube.

7. A desulfurization device based on zoned flow guidance and liquid film redistribution according to claim 1, characterized in that: A spray layer is installed inside the desulfurization tower located above the liquid receiving hopper.

8. A desulfurization device based on zoned flow guidance and liquid film redistribution according to claim 7, characterized in that: A baffle demister is installed inside the desulfurization tower above the spray layer.

9. A desulfurization method using the desulfurization device according to any one of claims 1-8, characterized in that, The following steps are included: (1) After the sulfur-containing flue gas enters the desulfurization tower, the flue gas on the side wall is corrected by the compartment pressure equalization guide mechanism and flows upward, and comes into countercurrent contact with the slurry sprayed from the upper spray layer to carry out the desulfurization reaction, and comes into contact with the outer liquid film on the outer wall of the guide tube for secondary washing. (2) The mainstream flue gas in the middle enters the guide tube after passing through the inner ring, and comes into countercurrent contact with the slurry sprayed from the upper spray layer to carry out desulfurization reaction, and comes into contact with the inner liquid curtain at high speed shear and disturbance. (3) The flue gas continues to rise after being washed and is discharged from the flue gas outlet at the top of the desulfurization tower after being demisted.

Images