A desulfurization device and method for flue gas from prebaked anode calcination.

Abstract

This disclosure relates to the field of flue gas desulfurization technology. One embodiment of this disclosure provides a prebaked anode calcination flue gas desulfurization device and method. The prebaked anode calcination flue gas desulfurization device includes a tower body, a main pipe, and nozzles. The tower body has a flue gas inlet and a flue gas outlet. The main pipe is located inside the tower body and is used to connect to a desulfurization liquid supply unit. The main pipe has a water outlet hole. The top end of the nozzle is ball-hinged into and connected to the water outlet hole, allowing the bottom end of the nozzle to rotate around the axis of the water outlet hole. The bottom end of the nozzle is the water outlet end. This technical solution solves the technical problems in related technologies where the contact direction between the slurry and flue gas is unidirectional, the contact is insufficient, and the desulfurization efficiency is low.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of flue gas desulfurization technology, specifically to a prebaked anode calcination flue gas desulfurization device and desulfurization method. Background Technology

[0002] In modern industrial production, prebaked anodes are a key raw material in aluminum electrolysis, and the environmental issues in their production process have attracted much attention. In particular, the calcination process of prebaked anodes generates a large amount of flue gas containing pollutants such as sulfur dioxide. If this flue gas is directly emitted without effective treatment, it will cause serious harm to the environment.

[0003] Currently, limestone gypsum spraying for flue gas desulfurization is a commonly used desulfurization technology. Its basic principle is that when flue gas comes into contact with the slurry, sulfur dioxide in the flue gas first dissolves in the water, transferring from the gas phase to the liquid phase. Then, it comes into more thorough contact with the slurry, reacting well with components such as calcium hydroxide in the lime slurry, ultimately achieving desulfurization.

[0004] However, in current technology, lime slurry is sprayed downwards, making countercurrent contact with upward-flowing flue gas. Through a chemical reaction, sulfur dioxide is absorbed, producing gypsum, which can then be used as a byproduct in the building materials industry. However, the countercurrent contact between the slurry and flue gas is unidirectional and insufficient, affecting the sufficiency of the reaction and the desulfurization efficiency.

[0005] In summary, existing prebaked anode calcination flue gas desulfurization methods suffer from problems such as a single direction of contact between the slurry and flue gas, insufficient contact, and low desulfurization efficiency. There is an urgent need to develop a new prebaked anode calcination flue gas desulfurization device to solve these problems. Summary of the Invention

[0006] To overcome the above-mentioned defects, the embodiments of this disclosure provide a desulfurization device and method for prebaked anode calcination flue gas, which solves the technical problems of unidirectional contact between slurry and flue gas, insufficient contact, and low desulfurization efficiency in related technologies.

[0007] According to one aspect, at least one embodiment of this disclosure provides a prebaked anode calcination flue gas desulfurization device, including a tower body, a main pipe, and a nozzle. The tower body has a flue gas inlet and a flue gas outlet. The main pipe extends through the tower body into the tower body and is used to connect to a desulfurization liquid supply unit and to transport desulfurization liquid into the tower body. The main pipe has a water outlet hole. The top end of the nozzle is ball-hinged in the water outlet hole and communicates with the water outlet hole. The nozzle is capable of circumferential movement around the axis of the water outlet hole, and the bottom end of the nozzle is the water outlet end.

[0008] For example, in at least one embodiment of this disclosure, a prebaked anode calcination flue gas desulfurization device further includes:

[0009] A rotating frame is installed inside the tower body, moving along a circular trajectory. The rotating frame is eccentrically arranged relative to the axis of the tower body. The rotating frame has a mounting hole through which the nozzle passes. The middle part of the nozzle is spherically hinged in the mounting hole. The rotating frame is used to drive the bottom end of the nozzle to make a circular motion around the axis of the water outlet.

[0010] For example, in at least one embodiment of this disclosure, a prebaked anode calcination flue gas desulfurization device further includes:

[0011] The support and crank assembly are provided. The support is located inside the tower body, and the crank assembly is hinged at both ends to the support and the rotating frame, respectively. The crank assembly is used to drive the rotating frame to move.

[0012] For example, in at least one embodiment of this disclosure, a prebaked anode calcination flue gas desulfurization device further includes:

[0013] The drive motor, the first bevel gear, and the second bevel gear are connected to the outer wall of the tower body. The first bevel gear and the second bevel gear are both rotatably disposed inside the tower body. The first bevel gear meshes with the second bevel gear. The drive motor is driven to the first bevel gear to drive the first bevel gear to rotate. The second bevel gear is driven to the crank assembly to drive the crank assembly to rotate.

[0014] For example, in at least one embodiment of this disclosure, a prebaked anode calcination flue gas desulfurization device further includes:

[0015] The pretreatment box and the partition are provided. The pretreatment box is located inside the tower body and below the nozzle. The flue gas inlet is connected to the pretreatment box. The partition is located on the top of the pretreatment box. There is a flue gas outlet between the partition and the pretreatment box. The flue gas outlet is connected to the tower body. There is a gap between the outer periphery of the pretreatment box and the inner wall of the tower body.

[0016] For example, in at least one embodiment of this disclosure, a prebaked anode calcination flue gas desulfurization device further includes:

[0017] The system comprises a humidification tank, a humidification pipe, and a pump. The humidification tank is located inside the pretreatment box and contains humidification liquid. The humidification pipe is located inside the humidification tank, with its lower end connected to the humidification tank. The top of the humidification pipe has an outlet hole for the humidification liquid to flow out and form a water curtain around the outer periphery of the humidification pipe for humidifying the flue gas. The pump is located inside the humidification pipe and is used to continuously pump the humidification liquid from the humidification tank into the humidification pipe.

[0018] For example, in at least one embodiment of this disclosure, a prebaked anode calcination flue gas desulfurization device further includes:

[0019] The liquid outlet is inclined, and the height of the liquid outlet gradually decreases in the direction away from the center of the humidification tube. The diameter of the partition is smaller than the diameter of the top of the pretreatment tank.

[0020] For example, in at least one embodiment of this disclosure, a prebaked anode calcination flue gas desulfurization device further includes:

[0021] The outer wall of the humidification tube is a sloping surface, an arc surface, or a stepped surface.

[0022] For example, in at least one embodiment of this disclosure, a prebaked anode calcination flue gas desulfurization device further includes:

[0023] The heat exchange coil is located inside the pretreatment box and surrounds the humidification pipe. The heat exchange coil is spiral-shaped. The water tank is located next to the tower body. Both ends of the heat exchange coil are connected to the water tank.

[0024] Another embodiment of this disclosure provides a method for desulfurizing flue gas from prebaked anode calcination, which uses a prebaked anode calcination flue gas desulfurization device and includes the following steps:

[0025] S1 flue gas pretreatment: High-temperature flue gas first enters the pretreatment box through the flue gas inlet and comes into contact with the water curtain formed on the outer wall of the humidification tube, resulting in water evaporation and humidification of the high-temperature flue gas.

[0026] S2 flue gas waste heat recovery: Circulating water is circulated inside the heat exchange coil, and both ends are connected to water sources. High-temperature flue gas fully contacts the outer wall of the heat exchange coil in the pretreatment box to achieve efficient waste heat recovery.

[0027] S3 spray high-efficiency desulfurization: The flue gas discharged from the pretreatment box comes into full contact with the desulfurization liquid sprayed by the nozzle. The bottom of the nozzle makes a circular motion, so that the desulfurization liquid continuously changes the angle of contact with the flue gas, thus achieving high-efficiency desulfurization.

[0028] The beneficial effects of the embodiments disclosed herein are as follows:

[0029] In this disclosure, the nozzle outlet rotates in a circular motion around the outlet hole axis, allowing the slurry to contact the flue gas from multiple different angles. This changes the previous technology where the slurry and flue gas only contacted each other in a single counter-current direction. This multi-angle contact method increases the contact area and contact time between the slurry and flue gas, giving sulfur dioxide more opportunities to dissolve in the slurry and react with components such as calcium hydroxide, thereby significantly improving the sufficiency of the reaction. Compared to traditional desulfurization devices, the desulfurization device of this invention can process more sulfur dioxide in the same amount of time, or achieve higher desulfurization precision when processing the same amount of sulfur dioxide, effectively improving desulfurization efficiency. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments of this disclosure will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of this disclosure and these drawings without any creative effort.

[0031] Figure 1 This is a schematic diagram of the external appearance of a prebaked anode calcination flue gas desulfurization device according to one embodiment of the present disclosure;

[0032] Figure 2 for Figure 1 A schematic diagram of the internal structure of a prebaked anode calcination flue gas desulfurization device in one embodiment;

[0033] Figure 3 for Figure 2 Enlarged view of point B in the embodiment;

[0034] Figure 4 for Figure 1 A schematic diagram of the rotating frame in the embodiment;

[0035] Figure 5 for Figure 1 A schematic diagram of the eccentric structure between the rotating frame and the main pipe in the embodiment;

[0036] Figure 6 for Figure 2 Enlarged view of point A in the embodiment.

[0037] In the diagram: 1. Tower body, 2. Main pipe, 3. Nozzle, 4. Flue gas inlet, 5. Flue gas outlet, 6. Water outlet, 7. Rotating frame, 8. Mounting hole, 9. Support, 10. Crank assembly, 11. Pretreatment box, 12. Baffle plate, 13. Flue gas outlet, 14. Humidification tank, 15. Humidification pipe, 16. Pump body, 17. Liquid outlet, 18. Heat exchange coil, 19. Drive motor, 20. First bevel gear, 21. Second bevel gear. Detailed Implementation

[0038] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present disclosure and are not intended to limit the scope of the disclosure.

[0039] To keep the drawings concise, each drawing only schematically shows the parts relevant to the disclosure; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0040] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0041] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0042] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0043] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0044] like Figures 1-6The diagram illustrates a prebaked anode calcination flue gas desulfurization device according to an embodiment of this disclosure, comprising a tower body 1, a main pipe 2, and a nozzle 3. The tower body 1 has a flue gas inlet 4 and a flue gas outlet 5. The main pipe 2 extends through the tower body 1 into the tower body 1 and is used to connect to a desulfurization liquid supply unit and to transport desulfurization liquid into the tower body 1. The main pipe 2 has a water outlet 6. The top end of the nozzle 3 is ball-hinged into the water outlet 6 and communicates with the water outlet 6. The nozzle 3 is capable of circumferential motion around the axis of the water outlet 6, and the bottom end of the nozzle 3 is the water outlet end.

[0045] For example, such as Figures 2-5 As shown, the flue gas containing sulfur dioxide generated by the calcination of the prebaked anode enters the tower body 1 through the flue gas inlet 4. Simultaneously, the desulfurization liquid supply unit delivers lime slurry to the interior of the tower body 1 via the main pipeline 2. Since the top ball of the nozzle 3 is hinged within and connected to the water outlet 6 of the main pipeline 2, the slurry is sprayed out from the water outlet at the bottom of the nozzle 3 under the pressure of the slurry.

[0046] Then, the water outlet at the bottom of nozzle 3 begins to rotate around the axis of water outlet 6. During this rotation, the lime slurry sprayed from the water outlet of nozzle 3 comes into contact with the upward-flowing flue gas at a constantly changing angle. As nozzle 3 continues its circular motion, the slurry forms a relatively three-dimensional spray area within tower 1, comprehensively covering the flow path of the flue gas. In this process, sulfur dioxide in the flue gas first dissolves in the water contained in the sprayed slurry, transferring from the gas phase to the liquid phase. Then, sulfur dioxide reacts chemically with components such as calcium hydroxide in the slurry. The resulting gypsum falls to the bottom of tower 1 with the slurry and can be collected as a byproduct for use in the building materials industry.

[0047] The nozzle 3's outlet end rotates in a circular motion around the axis of the outlet hole 6, allowing the slurry to contact the flue gas from multiple different angles. This changes the previous technology's single-direction counter-current contact between the slurry and flue gas. This multi-angle contact method increases the contact area and contact time between the slurry and flue gas, giving sulfur dioxide more opportunities to dissolve in the slurry and react with components such as calcium hydroxide, thus significantly improving the sufficiency of the reaction. Compared to traditional desulfurization devices, the desulfurization device of this invention can process more sulfur dioxide in the same amount of time, or achieve higher desulfurization precision when processing the same amount of sulfur dioxide, effectively improving desulfurization efficiency.

[0048] In some examples, a rotating frame 7 is also included, which is moved along a circular trajectory within the tower body 1. The rotating frame 7 is eccentrically arranged relative to the axis of the tower body 1. The rotating frame 7 has a mounting hole 8 through which the nozzle 3 passes. The middle part of the nozzle 3 is spherically hinged in the mounting hole 8. The rotating frame 7 is used to drive the bottom end of the nozzle 3 to perform a circular motion around the axis of the water outlet 6.

[0049] For example, such as Figures 2-5 As shown, after the prebaked anode calcination flue gas enters the tower body 1 through the flue gas inlet 4, the rotating frame 7 begins to operate. Since the middle ball of the nozzle 3 is hinged in the mounting hole 8 of the rotating frame 7, the rotation of the rotating frame 7 will cause the nozzle 3 to twist. Driven by the rotating frame 7, the water outlet end at the bottom of the nozzle 3 moves along a circular trajectory.

[0050] Main pipeline 2 delivers lime slurry from the desulfurization liquid supply unit to nozzle 3. The slurry sprayed from the outlet of nozzle 3 continuously changes its spray angle as the nozzle 3 is adjusted. During this process, the slurry sprayed at different angles comes into full contact with the rising flue gas. Sulfur dioxide in the flue gas quickly dissolves in the slurry and reacts fully with components such as calcium hydroxide in the slurry. The resulting gypsum settles to the bottom of tower 1 and is collected and processed by subsequent equipment.

[0051] The nozzle 3 is spherically hinged to the rotating frame 7 in the middle. The rotating frame 7 can drive the nozzle 3 to rotate, causing the spray angle to continuously change, forming a more complex and comprehensive spray coverage area within the tower body 1. This ensures full contact between the slurry and the flue gas at different locations within the tower body 1, further increasing the gas-liquid contact area and improving the sufficiency of the desulfurization reaction. The multi-angle, all-round spraying method makes the reaction between sulfur dioxide and the slurry more complete and efficient, thereby significantly improving the desulfurization efficiency.

[0052] In some examples, a support 9 and a crank 10 are also included. The support 9 is disposed inside the tower body 1, and the crank 10 is hinged at both ends to the support 9 and the rotating frame 7, respectively. The crank 10 is used to drive the rotating frame 7 to move.

[0053] For example, such as Figures 2-5 As shown, the support 9 is installed at a predetermined position on the inner wall of the tower body 1, providing a supporting foundation for the transmission structure. One end of the crank 10 is hinged to the support 9, and the other end is hinged to the rotating frame 7. When the desulfurization unit starts operating, the drive source (such as a motor) provides power to the crank 10, causing it to start rotating.

[0054] As the crank assembly 10 rotates, due to the hinged structure at both ends, the crank assembly 10 transmits the rotational force to the rotating frame 7. This allows the rotating frame 7 to rotate around the axis of the tower body 1. Because the ball joint in the middle of the nozzle 3 is hinged in the mounting hole 8 of the rotating frame 7, the rotation of the rotating frame 7 causes the nozzle 3 to twist, and the water outlet at the bottom of the nozzle 3 moves along a circular trajectory, achieving multi-angle spraying.

[0055] A stable transmission structure is constructed through the cooperation of the bracket 9 and the crank component 10. The hinged design at both ends of the crank component 10 ensures smooth power transmission, allowing the rotating frame 7 to rotate continuously and stably. This, in turn, ensures that the nozzle 3 can adjust its angle and perform spraying operations according to a predetermined trajectory, providing a solid guarantee for the stable operation of the desulfurization unit.

[0056] In some examples, a drive motor 19, a first bevel gear 20, and a second bevel gear 21 are also included. The drive motor 19 is connected to the outer wall of the tower body 1. The first bevel gear 20 and the second bevel gear 21 are both rotatably disposed inside the tower body 1. The first bevel gear 20 meshes with the second bevel gear 21. The drive motor 19 is drivenly connected to the first bevel gear 20 to drive the first bevel gear 20 to rotate. The second bevel gear 21 is drivenly connected to the crank component 10 to drive the crank component 10 to rotate.

[0057] For example, such as Figure 2 As shown, when the desulfurization unit starts, the drive motor 19 is energized and operates. The motor is located on the outer wall of the tower body 1, and its power output shaft is connected to the first bevel gear 20 inside the tower body 1, driving the first bevel gear 20 to start rotating. Since the first bevel gear 20 and the second bevel gear 21 mesh with each other, the rotation of the first bevel gear 20 is transmitted to the second bevel gear 21, causing it to rotate synchronously. The second bevel gear 21 is coaxially equipped with a pulley, and the hinge end of the crank component 10 is also coaxially equipped with a pulley. A transmission belt is fitted on the two pulleys, thereby causing the second bevel gear 21 to drive the crank component 10 to rotate around the hinge point. The rotation of the crank component 10 drives the rotating frame 7, which is hinged to it, to rotate around the axis of the tower body 1, ultimately achieving the effect of multi-angle spraying from the nozzle 3. The pulley and transmission belt can also be replaced with sprockets and chains.

[0058] In some examples, a pretreatment box 11 and a partition 12 are also included. The pretreatment box 11 is located inside the tower body 1 and below the nozzle 3. The flue gas inlet 4 communicates with the pretreatment box 11. The partition 12 is located on top of the pretreatment box 11. A smoke passage 13 is provided between the partition 12 and the pretreatment box 11. The smoke passage 13 communicates with the tower body 1. There is a gap between the outer periphery of the pretreatment box 11 and the inner wall of the tower body 1.

[0059] For example, such as Figure 6As shown, flue gas enters the pretreatment box 11 through flue gas inlet 4. Various pretreatment components can be installed inside the pretreatment box 11, such as heat exchange components. As the flue gas flows within the pretreatment box 11, it exchanges heat with the heat exchange components, achieving waste heat recovery. The recovered heat can be used to preheat the desulfurization liquid or other processes requiring thermal energy. Another example is the installation of filter components to filter impurities from the flue gas.

[0060] The pretreated flue gas enters the main spray reaction zone of tower body 1 through the flue gas outlet 13 between the baffle 12 and the pretreatment box 11, where the nozzles 3 continuously spray lime slurry. The slurry comes into full contact with the rising flue gas, undergoing a desulfurization reaction. The reacted slurry falls onto the baffle 12 and then flows along the gap between the pretreatment box 11 and the inner wall of tower body 1 to the bottom of tower body 1. The slurry collected at the bottom of tower body 1 can be further processed.

[0061] By installing a pretreatment box 11 inside the tower body 1, various pretreatment components can be installed as needed, thereby performing various pretreatments on the flue gas and improving the flexibility of flue gas treatment. Integrating the flue gas pretreatment function inside the tower body 1 simplifies the structure of the entire desulfurization system, reduces the equipment footprint and construction costs, and improves the functional integration of the device.

[0062] In some examples, a humidification tank 14, a humidification pipe 15, and a pump body 16 are also included. The humidification tank 14 is located inside the pretreatment box 11 and contains humidification liquid. The humidification pipe 15 is located inside the humidification tank 14, with its lower end connected to the humidification tank 14. The top of the humidification pipe 15 has a liquid outlet 17 for allowing the humidification liquid to flow out and forming a water curtain around the outer periphery of the humidification pipe 15 for humidifying the flue gas. The pump body 16 is located inside the humidification pipe 15 and is used to continuously pump the humidification liquid from the humidification tank 14 into the humidification pipe 15.

[0063] For example, such as Figure 6 As shown, the basic principle of limestone gypsum spray flue gas desulfurization is that sulfur dioxide in the flue gas needs to first dissolve in water and transfer from the gas phase to the liquid phase in order to fully contact the slurry and then react well with components such as calcium hydroxide in the lime slurry, ultimately achieving the purpose of desulfurization.

[0064] However, in actual prebaked anode calcination processes, the resulting flue gas is very dry with low humidity. When using lime-gypsum spraying for flue gas desulfurization, in the initial stage of contact between the flue gas and the slurry, the flue gas lacks its own moisture to promote the dissolution of sulfur dioxide and can only rely on the moisture in the slurry. This results in a large amount of slurry moisture being used to dissolve sulfur dioxide in the initial stage of the reaction, preventing the effective components in the slurry (such as calcium hydroxide) from participating in the reaction in a timely and sufficient manner, thus reducing the utilization rate of the slurry. At the same time, because dissolving sulfur dioxide consumes a lot of time, the entire desulfurization reaction process is delayed, and the desulfurization efficiency is reduced accordingly. In addition, to achieve a certain desulfurization effect, it is necessary to increase the spraying volume of slurry, which not only increases operating costs but may also lead to difficulties in subsequent treatment, such as generating more desulfurization wastewater and gypsum waste residue.

[0065] In this embodiment, the dry, high-temperature flue gas generated by the calcination of the prebaked anode enters the pretreatment box 11 from the flue gas inlet 4. The pump body 16 continuously pumps the humidifying liquid in the humidification tank 14 into the humidification pipe 15. The humidifying liquid flows out from the outlet hole 17 at the top of the humidification pipe 15. Due to gravity and liquid surface tension, the humidifying liquid flows down evenly along the outer wall of the humidification pipe 15, forming a continuous water curtain.

[0066] A wire hole can be opened on the side wall of the humidification pipe 15, and the connection line of the pump body 16 passes through the wire hole to connect with the external control components and power supply, thereby realizing the control of the operation of the pump body 16.

[0067] When dry, high-temperature flue gas flows through the water curtain surrounding the humidification pipe 15, heat is transferred from the flue gas to the surface of the water curtain. The sensible heat in the flue gas causes some of the liquid water on the surface of the water curtain to absorb heat and undergo a phase change, evaporating into water vapor. During this process, the temperature of the flue gas decreases significantly, while its absolute humidity increases, approaching saturation. The humidified flue gas, carrying a suitable amount of moisture, continues upward through the flue gas outlet 13 into the main spray reaction zone of the tower body 1. Because the flue gas already possesses suitable humidity conditions, sulfur dioxide can quickly dissolve in the moisture carried by the flue gas itself and in the slurry, reacting rapidly with components such as calcium hydroxide in the slurry.

[0068] By humidifying the flue gas during the pretreatment stage, a suitable humidity environment is created for the subsequent desulfurization reaction. When the flue gas comes into contact with the lime slurry, it no longer relies excessively on the water in the slurry to dissolve sulfur dioxide. This allows the effective components in the slurry (such as calcium hydroxide) to participate more fully in the desulfurization reaction, improving the slurry utilization rate and reducing waste. There is no need to significantly increase the slurry spraying volume to compensate for the impact of flue gas drying on desulfurization efficiency. This reduces the amount of desulfurizing agent used and lowers operating costs.

[0069] In some examples, the outlet hole 17 is inclined, the height of the outlet hole 17 gradually decreases in the direction away from the center of the humidification tube 15, and the diameter of the partition 12 is smaller than the diameter of the top of the pretreatment tank 11.

[0070] For example, such as Figure 6 As shown, the flue gas outlet 13 is inclined and its height gradually decreases in the direction away from the center of the humidification pipe 15. This structure effectively prevents the slurry sprayed by the nozzle 3 from flowing into the pretreatment box 11.

[0071] The lime slurry sprayed from nozzle 3 flows downwards along baffle 12. Because the diameter of baffle 12 is smaller than the diameter of the top of pretreatment tank 11, the slurry falls onto the wall of flue gas outlet 13 as it falls from baffle 12. It then flows along the inclined wall of flue gas outlet 13 into the space between the pretreatment tank 11 and the inner wall of tower body 1. This creates a water curtain between baffle 12 and the wall of flue gas outlet 13. When flue gas passes through flue gas outlet 13, it comes into contact with this water curtain, achieving secondary humidification. This creates more favorable humidity conditions for subsequent desulfurization reactions, improves the dissolution efficiency of sulfur dioxide in the slurry, and thus enhances desulfurization efficiency.

[0072] The gradually decreasing height of the flue gas outlet 13 effectively prevents the slurry sprayed from the nozzle 3 from flowing directly into the pretreatment tank 11, thus preventing equipment inside the pretreatment tank 11 (such as the humidification tank 14, heat exchange coil 18, etc.) from being contaminated by the slurry. This ensures the normal operation of the pretreatment process and extends the service life of the equipment. Utilizing the structural design of the baffle 12 and the flue gas outlet 13, the secondary humidification function is achieved without increasing the equipment volume, making full use of the internal space of the tower body 1.

[0073] In some examples, the outer wall of the humidification tube 15 is a sloped surface, an arc surface, or a stepped surface.

[0074] For example, such as Figure 6 As shown, when the pump body 16 pumps the humidifying liquid from the humidification tank 14 into the humidification pipe 15, the humidifying liquid flows out from the top outlet 17. Dry, high-temperature flue gas flows within the pretreatment box 11, passing through the humidification pipe 15 with its specially shaped outer wall. The flue gas comes into full contact with the water curtain, heat is rapidly transferred, and water vapor continuously evaporates into the flue gas, effectively increasing its humidity and preparing it for subsequent desulfurization reactions. The design of the inclined, curved, or stepped surfaces allows the water curtain to extend more fully in three-dimensional space. The flue gas after large-area water curtain humidification treatment shows a more significant increase in humidity. Without increasing the equipment volume or the amount of humidifying liquid used, the contact area between the water curtain and the flue gas is increased by changing the shape of the outer wall of the humidification pipe 15, achieving efficient utilization of the equipment.

[0075] In some examples, a heat exchange coil 18 and a water tank are also included. The heat exchange coil 18 is located inside the pretreatment box 11 and surrounds the humidification pipe 15. The heat exchange coil 18 is spiral-shaped. The water tank is used to be located next to the tower body 1. Both ends of the heat exchange coil 18 are used to connect to the water tank.

[0076] For example, such as Figure 6 As shown, a spiral heat exchange coil 18 surrounds the humidification tube 15, and a water tank is located outside the tower body 1. Water in the tank flows into the heat exchange coil 18 from one end. The heat from the high-temperature flue gas is transferred to the water inside the heat exchange coil 18. After absorbing the heat from the flue gas, the water temperature gradually rises, forming hot water that flows out from the other end of the heat exchange coil 18 and returns to the water tank. The water in the tank can be reused, for example, for other processes within the plant that require hot water, such as preheating desulfurization liquid and heating domestic water.

[0077] Throughout the process, the spiral design ensures that the heat exchange coil 18 has sufficient length to contact the flue gas, guaranteeing that heat is fully transferred from the flue gas to the water, achieving efficient waste heat recovery. At the same time, the humidification tube 15 and the heat exchange coil 18 work together without interfering with each other, achieving both humidification of the flue gas and effective recovery of waste heat.

[0078] The reduced flue gas temperature after waste heat recovery facilitates subsequent desulfurization reactions and improves desulfurization efficiency. Simultaneously, the heated water can be used to preheat the desulfurization liquid, ensuring it enters the reaction zone at a more suitable temperature. The design of the heat exchange coil 18 surrounding the humidification tube 15 fully utilizes the space within the pretreatment tank 11, resulting in a more compact equipment structure. This integrated design reduces the equipment's footprint and simplifies installation and maintenance.

[0079] Another embodiment of this disclosure discloses a method for desulfurizing flue gas from prebaked anode calcination, which uses a prebaked anode calcination flue gas desulfurization device and includes the following steps:

[0080] S1 Flue gas pretreatment: High-temperature flue gas first enters the pretreatment box 11 through flue gas inlet 4, and comes into contact with the water curtain formed on the outer wall of the humidification pipe 15, resulting in water evaporation and humidification treatment of the high-temperature flue gas.

[0081] S2 flue gas waste heat recovery: The heat exchange coil 18 is filled with circulating water, and both ends are connected to water sources. The high-temperature flue gas in the pretreatment box 11 fully contacts the outer wall of the heat exchange coil 18 to achieve efficient waste heat recovery.

[0082] S3 spray high-efficiency desulfurization: The flue gas discharged from the pretreatment box 11 comes into full contact with the desulfurization liquid sprayed by the nozzle 3. The bottom of the nozzle 3 makes a circular motion, so that the desulfurization liquid continuously changes the angle of contact with the flue gas, thus achieving high-efficiency desulfurization.

[0083] For example, by humidifying the flue gas during the pretreatment stage, a suitable humidity environment is created for the subsequent desulfurization reaction. When the flue gas comes into contact with the lime slurry, it no longer relies excessively on the water in the slurry to dissolve sulfur dioxide. The lower temperature of the flue gas after waste heat recovery is beneficial to the subsequent desulfurization reaction, improving desulfurization efficiency. At the same time, the heated water can be used to preheat the desulfurization liquid, ensuring that the desulfurization liquid is at a more suitable temperature when entering the reaction zone. The water outlet of nozzle 3 moves in a circular motion around the axis of water outlet hole 6, allowing the slurry to contact the flue gas from multiple different angles, improving the adequacy of contact.

[0084] It should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure and are not intended to limit it. Although this disclosure has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this disclosure without departing from the spirit and scope of the technical solutions of this disclosure, and all such modifications and substitutions should be covered within the scope of the claims of this disclosure.

Claims

1. A prebaked anode calcination flue gas desulfurization device, characterized in that, The device includes a tower body (1), a main pipe (2), and a nozzle (3). The tower body (1) has a flue gas inlet (4) and a flue gas outlet (5). The main pipe (2) extends through the tower body (1) into the tower body (1). The main pipe (2) is used to connect to the desulfurization liquid supply unit and to transport desulfurization liquid into the tower body (1). The main pipe (2) has a water outlet (6). The top end of the nozzle (3) is spherically hinged to the water outlet (6) and communicates with the water outlet (6). The nozzle (3) can make circular motion around the axis of the water outlet (6). The bottom end of the nozzle (3) is the water outlet end. It also includes a pretreatment box (11) and a partition (12). The pretreatment box (11) is located inside the tower body (1) and below the nozzle (3). The flue gas inlet (4) is connected to the pretreatment box (11). The partition (12) is located on the top of the pretreatment box (11). There is a smoke passage (13) between the partition (12) and the pretreatment box (11). The smoke passage (13) is connected to the tower body (1). There is a gap between the outer periphery of the pretreatment box (11) and the inner wall of the tower body (1). It also includes a humidification tank (14), a humidification pipe (15), and a pump body (16). The humidification tank (14) is located inside the pretreatment box (11). The humidification tank (14) contains humidification liquid. The humidification pipe (15) is located inside the humidification tank (14). The lower end of the humidification pipe (15) is connected to the humidification tank (14). The top of the humidification pipe (15) has a liquid outlet hole (17). The liquid outlet hole (17) is used to supply the humidification liquid to flow out and form a water curtain for humidifying flue gas around the humidification pipe (15). The pump body (16) is located inside the humidification pipe (15) and is used to continuously pump the humidification liquid in the humidification tank (14) into the humidification pipe (15).

2. The prebaked anode calcination flue gas desulfurization device according to claim 1, characterized in that, It also includes a rotating frame (7), which moves along a circular trajectory within the tower body (1). The rotating frame (7) is eccentrically arranged relative to the axis of the tower body (1). The rotating frame (7) has a mounting hole (8) through which the nozzle (3) passes. The middle part of the nozzle (3) is spherically hinged in the mounting hole (8). The rotating frame (7) is used to drive the bottom end of the nozzle (3) to make a circular motion around the axis of the water outlet (6).

3. The prebaked anode calcination flue gas desulfurization device according to claim 2, characterized in that, It also includes a bracket (9) and a crank (10). The bracket (9) is located inside the tower body (1). The two ends of the crank (10) are respectively hinged to the bracket (9) and the rotating frame (7). The crank (10) is used to drive the rotating frame (7) to move.

4. The prebaked anode calcination flue gas desulfurization device according to claim 3, characterized in that, It also includes a drive motor (19), a first bevel gear (20) and a second bevel gear (21). The drive motor (19) is connected to the outer wall of the tower body (1). The first bevel gear (20) and the second bevel gear (21) are rotatably disposed inside the tower body (1). The first bevel gear (20) meshes with the second bevel gear (21). The drive motor (19) is driven to the first bevel gear (20) to drive the first bevel gear (20) to rotate. The second bevel gear (21) is driven to the crank component (10) to drive the crank component (10) to rotate.

5. The prebaked anode calcination flue gas desulfurization device according to claim 1, characterized in that, The outlet hole (17) is inclined, and the height of the outlet hole (17) gradually decreases along the direction away from the center of the humidification tube (15). The diameter of the partition (12) is smaller than the diameter of the top of the pretreatment box (11).

6. The prebaked anode calcination flue gas desulfurization device according to claim 1, characterized in that, The outer wall of the humidification tube (15) is a slope, an arc, or a stepped surface.

7. The prebaked anode calcination flue gas desulfurization device according to claim 1, characterized in that, It also includes a heat exchange coil (18) and a water tank. The heat exchange coil (18) is located inside the pretreatment box (11) and surrounds the humidification pipe (15). The heat exchange coil (18) is spiral-shaped. The water tank is used to be installed next to the tower body (1). Both ends of the heat exchange coil (18) are used to connect to the water tank.

8. A method for desulfurizing flue gas from prebaked anode calcination, characterized in that, Using the prebaked anode calcination flue gas desulfurization device according to claim 7 includes the following steps: S1 flue gas pretreatment: High-temperature flue gas first enters the pretreatment box (11) through the flue gas inlet (4), and comes into contact with the water curtain formed on the outer wall of the humidification pipe (15), resulting in water evaporation and humidification treatment of the high-temperature flue gas; S2 flue gas waste heat recovery: Circulating water is circulated inside the heat exchange coil (18), and both ends are connected to water sources. The high-temperature flue gas fully contacts the outer wall of the heat exchange coil (18) in the pretreatment box (11) to achieve efficient waste heat recovery. S3 spray high-efficiency desulfurization: The flue gas discharged from the pretreatment box (11) comes into full contact with the desulfurization liquid sprayed by the nozzle (3). The bottom of the nozzle (3) makes a circular motion, so that the desulfurization liquid continuously changes the angle of contact with the flue gas, and performs high-efficiency desulfurization.

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