A lime flue gas brine purification device

Abstract

The application relates to a lime flue gas brine purification device, which comprises a primary reactor, the upper portion of the primary reactor is provided with a brine inlet and a calcium hydroxide solution inlet, the bottom portion is provided with a first reaction liquid outlet and a first slurry outlet; a secondary reaction tower, the secondary reaction tower is a tower type gas-liquid reaction equipment, the secondary reaction tower is provided with an internal tower component, the internal tower component is used for intensifying gas-liquid contact and reaction of carbon dioxide-containing gas and brine; the upper portion of the secondary reaction tower is provided with a first reaction liquid inlet and a tail gas outlet, the lower portion of the secondary reaction tower is provided with a flue gas inlet, a second reaction liquid outlet and a second slurry outlet; the internal tower component comprises a cyclone plate, the cyclone plate comprises a blind plate and guide vanes which are arranged in the circumferential direction of the blind plate, and an adjusting assembly is arranged on the blind plate. The application can effectively improve the treatment efficiency and reduce the plugging problem.

Description

Technical Field

[0001] This application relates to the technical field of brine refining, specifically to a lime flue gas brine purification device. Background Technology

[0002] In industrial production such as salt making and chlor-alkali production, brine refining is a crucial step in ensuring the quality of subsequent products and production efficiency. The raw brine contains impurities such as calcium and magnesium ions. If these are not removed, they will form calcium and magnesium scale on the surface of heat exchange equipment during the subsequent evaporation and salt production process, which will seriously affect heat transfer efficiency and increase energy consumption and equipment maintenance costs.

[0003] In related technologies, the lime-carbon dioxide method (also known as the lime-flue gas method) is widely used in industry for two-stage purification of brine. The principle of this process is as follows: First, a calcium hydroxide solution (prepared from calcium oxide) is added to the brine, causing magnesium ions to react with hydroxide ions to form magnesium hydroxide precipitate, achieving primary magnesium removal; then, carbon dioxide gas (usually from boiler flue gas) is passed through the clarified liquid, causing calcium ions to form calcium carbonate precipitate, achieving secondary calcium removal (carbonization reaction).

[0004] However, the above-mentioned technologies have the following prominent problems in practical applications: low reaction efficiency, as the reactions are all carried out in large clarification tanks or reaction vessels. Clarification tanks typically have a diameter of 15-20 meters, and the gas-liquid contact method is limited to simple pipe ventilation combined with mechanical stirring, resulting in a long reaction residence time. The equipment is prone to clogging, and the calcium carbonate precipitate generated by the carbonation reaction typically has a particle size of 1-50 micrometers. In the clarification tank, these solid particles easily deposit and form scale on the tank walls, stirring shaft, gas distribution pipes, and connecting pipes. To remove the deposits, periodic shutdowns for manual cleaning are required, resulting in high maintenance costs and disruption to continuous production. Summary of the Invention

[0005] To address the problems existing in the prior art, this application provides a lime flue gas brine purification device. The device includes: a primary reactor, wherein the upper part of the primary reactor is provided with a brine inlet and a calcium hydroxide solution inlet, and the bottom is provided with a first reaction liquid outlet and a first slurry outlet; a secondary reaction tower, wherein the secondary reaction tower is a tower-type gas-liquid reaction device, and the secondary reaction tower is provided with internal components for enhancing the gas-liquid contact and reaction between carbon dioxide-containing gas and brine; the upper part of the secondary reaction tower is provided with a first reaction liquid inlet and a tail gas outlet, and the lower part of the secondary reaction tower is provided with a flue gas inlet, a second reaction liquid outlet, and a second slurry outlet; the internal components of the tower include a swirl plate, the swirl plate including a blind plate and guide vanes arranged circumferentially around the blind plate, the blind plate being rotatably mounted inside the secondary reaction tower via a main shaft, the guide vanes being rotatably mounted on the blind plate, and the blind plate being provided with an adjustment component for adjusting the angle of the guide vanes.

[0006] For example, the secondary reaction tower has multiple swirl plates arranged from top to bottom inside, and the guide vanes and the blind plate end faces form an angle, with the guide vanes on each swirl plate having a different inclination angle.

[0007] For example, there is a gap between two adjacent swirl plates, with a gap size of 400-800mm.

[0008] For example, the guide vanes are rotatably mounted around the blind plate via a rotating shaft, and an annular baffle is provided at the upper edge of the blind plate. The adjustment assembly includes an adjustment disk rotatably mounted inside the annular baffle. The adjustment disk and the guide vanes correspond one-to-one, and an adjustment rod is hinged between the adjustment disk and the guide vanes.

[0009] For example, an annular groove is provided on one side of the annular baffle, and an annular airbag strip is provided in the annular groove. A guide rod is provided on the outside of the airbag strip. The guide rod is slidably connected to the annular baffle and passes through the adjusting disk. A guide groove is provided on the guide rod. The guide groove is curved and the curvature is along the axial direction of the guide rod and bends in the circumferential direction. A locking block that cooperates with the guide groove is provided in the adjusting disk. The guide rod is used to drive the adjusting disk to rotate.

[0010] For example, an electric push rod is provided at the upper end of the blind plate. One end of the electric push rod is fixed to the blind plate, and the other end is connected to a movable rod. A piston is connected to the end of the movable rod. A sleeve is connected to the outside of the airbag strip. The sleeve communicates with the airbag strip, and the piston is movably installed inside the sleeve.

[0011] For example, the main shaft is a hollow tube, the main shaft and the blind plate are hollowly arranged, the blind plate has a storage space for accommodating cooling water, the top of the main shaft is connected to a first cooling pipe and is rotatably and sealingly connected to the first cooling pipe, the bottom of the main shaft is rotatably and sealingly connected to the bottom of the secondary reaction tower, and the bottom of the secondary reaction tower is connected to a second cooling pipe.

[0012] For example, the guide vane is hollow and rotatably connected to the blind plate via a rotating shaft. The two ends of the rotating shaft extend into the interior of the guide vane and the storage space, respectively. A bearing and a sealing ring are provided between the rotating shaft and the side wall of the blind plate.

[0013] For example, the flue gas inlet is used to introduce boiler flue gas, which contains at least carbon dioxide gas, and the flue gas inlet is also connected to a dust collector.

[0014] For example, the flue gas inlet is also connected to the booster fan to supplement gas power when the flue gas flow in the boiler is insufficient.

[0015] This application offers at least the following technical advantages: It employs a two-stage reaction tower instead of a traditional clarifier for carbonization and calcium removal. The swirl plate internals within the tower disperse the liquid into fine droplets or a thin film, utilizing the gas's own kinetic energy to generate swirling motion, increasing the gas-liquid contact area and thus improving treatment efficiency. By installing adjustment components on the blind flange, the inclination angle of the guide vanes can be adjusted according to changes in flue gas flow and brine treatment volume, maintaining the operating gas velocity within the tower within the optimal range. Furthermore, it prevents scale buildup on the tower internals, effectively solving the problem of easy clogging in existing clarifiers. Attached Figure Description

[0016] Figure 1 This is a structural block diagram of an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of the secondary reaction tower in an embodiment of this application.

[0018] Figure 3 This is a schematic diagram of the interior of the secondary reaction tower in an embodiment of this application.

[0019] Figure 4 This is a schematic diagram of the swirl plate structure in an embodiment of this application.

[0020] Figure 5 This is a schematic diagram of the top connection of the spindle in an embodiment of this application.

[0021] Figure 6 This is a schematic diagram of the cross-section of the swirl plate in an embodiment of this application.

[0022] Reference numerals: 1. Primary reactor; 2. Secondary reaction tower; 21. Flue gas inlet; 22. Tail gas outlet; 23. First reaction liquid inlet; 24. Second reaction liquid outlet; 25. First cooling pipe; 26. Second cooling pipe; 27. Second slurry outlet; 28. Booster fan; 3. Swirl plate; 30. Storage space; 31. Blind flange; 32. Guide vane; 33. Adjusting rod; 34. Rotating shaft; 4. Main shaft; 41. Connection port; 42. Sleeve; 43. Sealing gasket; 6. Annular baffle; 61. Annular groove; 62. Adjusting disc; 63. Guide rod; 64. Guide groove; 7. Airbag strip; 71. Electric push rod; 72. Sleeve. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application more apparent, exemplary embodiments according to this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of the embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. Based on the embodiments of this application described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of this application.

[0024] like Figures 1-6 As shown in the figure, this application provides a lime flue gas brine purification device, which is used to perform two-stage purification treatment on brine containing calcium ions and magnesium ions. The device includes a primary reactor 1 and a secondary reaction tower 2.

[0025] Primary reactor 1 is used for the primary magnesium removal reaction. The upper part of primary reactor 1 is equipped with a brine inlet and a calcium hydroxide solution inlet, used to introduce the raw brine to be purified and the calcium hydroxide solution (prepared from calcium oxide and water), respectively. The bottom of primary reactor 1 is equipped with a first reaction liquid outlet and a first slurry outlet. Inside primary reactor 1, magnesium ions in the brine react with hydroxide ions in the calcium hydroxide to form magnesium hydroxide precipitate. The reacted liquid (primary reaction liquid) is discharged from the first reaction liquid outlet, and the precipitated slurry is discharged from the first slurry outlet.

[0026] Secondary reaction tower 2 is used for secondary carbonization and calcium removal reactions. (Combined with...) Figure 2 and Figure 3 As shown, the secondary reaction tower 2 is a vertical cylindrical tower-type gas-liquid reaction device.

[0027] The upper part of the secondary reaction tower 2 is provided with a first reaction liquid inlet 23 and a tail gas outlet 22. The first reaction liquid inlet 23 is connected to the first reaction liquid outlet of the primary reactor 1 through a connecting pipe, and is used to receive the primary reaction liquid from the primary reactor 1. The tail gas outlet 22 is used to discharge the tail gas after the reaction.

[0028] The lower part of the secondary reaction tower 2 is equipped with a flue gas inlet 21, a second reaction liquid outlet 24, and a second slurry outlet 27. The flue gas inlet 21 is used to introduce boiler flue gas containing carbon dioxide (the CO2 concentration in the flue gas is approximately 8%~15%). The flue gas inlet 21 is also connected to a dust collector to remove dust and impurities from the flue gas. The flue gas inlet 21 is also connected to a booster fan 28, which supplements the gas flow when the boiler flue gas pressure is insufficient, maintaining the operating gas velocity within the tower within a set range.

[0029] The bottom of the secondary reaction tower 2 is connected to a second cooling pipe 26. The secondary reaction tower 2 is equipped with internal components to enhance the gas-liquid contact and reaction between the carbon dioxide-containing gas and the brine. In this embodiment, the internal components include multiple swirl plates 3 arranged from top to bottom (three layers in this embodiment), with a gap between adjacent layers of swirl plates 3, the gap being 400-800 mm, such as 600 mm.

[0030] Combination Figures 3 to 6As shown, each swirl plate 3 includes a blind plate 31 and multiple guide vanes 32 evenly arranged circumferentially around the blind plate 31. The blind plate 31 is a circular plate structure. The blind plate 31 is rotatably mounted inside the secondary reaction tower 2 via a main shaft 4. The main shaft 4 extends along the axial direction of the secondary reaction tower 2. An electric push rod 71 is provided at the upper end of the blind plate 31.

[0031] The guide vanes 32 are rotatably mounted around the blind plate 31 via the rotating shaft 34. An angle is formed between the guide vanes 32 and the end face of the blind plate 31. The guide vanes 32 on each swirl plate 3 have different inclination angles: the upper guide vanes 32 have an inclination angle of 35°, the middle guide vanes 32 have an inclination angle of 30°, and the lower guide vanes 32 have an inclination angle of 25°, forming a layered structure with decreasing inclination angles from top to bottom.

[0032] A ring-shaped baffle 6 is provided on the upper edge of the blind flange 31. An adjustment assembly for adjusting the angle of the guide vanes 32 is provided on the blind flange 31.

[0033] Specifically, the adjustment assembly includes an adjustment disc 62, an adjustment rod 33, an airbag strip 7, a guide rod 63, and an electric push rod 71. The adjustment disc 62 is rotatably mounted inside the annular baffle 6. The adjustment disc 62 and the guide vane 32 correspond one-to-one, and the adjustment rod 33 is hinged between the adjustment disc 62 and the guide vane 32. An annular groove 61 is provided on one side of the annular baffle 6, and an annular airbag strip 7 is provided in the annular groove 61. A guide rod 63 is provided on the outer side of the airbag strip 7, and the guide rod 63 is slidably connected to the annular baffle 6 and passes through the adjustment disc 62. A guide groove 64 is provided on the guide rod 63, and the guide groove 64 is curved in the direction of axial curvature along the guide rod 63 and circumferentially. A locking block that cooperates with the guide groove 64 is provided inside the adjustment disc 62, and the guide rod 63 is used to drive the adjustment disc 62 to rotate.

[0034] One end of the electric push rod 71 is fixed to the blind plate 31, and the other end is connected to a movable rod. A piston is connected to the end of the movable rod. A sleeve 72 is connected to the outside of the airbag strip 7. The sleeve 72 and the airbag strip 7 are connected. The piston is movably installed in the sleeve 72.

[0035] When the angle of the guide vane 32 needs to be adjusted, the electric push rod 71 pushes the piston to move within the sleeve 72, compressing or releasing the gas inside the airbag strip 7, causing the airbag strip 7 to expand or contract, thus driving the guide rod 63 to move axially. Because the guide groove 64 on the guide rod 63 is curved, the locking block inside the adjusting disc 62 moves circumferentially under the constraint of the guide groove 64, thereby causing the adjusting disc 62 to rotate. The rotation of the adjusting disc 62 synchronously drives all guide vanes 32 to rotate by the same angle via the adjusting rod 33, achieving a simultaneous change in the tilt angle of all guide vanes 32 in a single adjustment operation.

[0036] The spindle 4 is a hollow tube. A connection port 41 is connected to the top of the spindle 4, with an opening for cooling water flow. The top of the spindle 4 is rotatably connected to the first cooling pipe 25 via a sleeve 42. A sealing gasket 43 is also provided at the bottom of the connection port 41, thus forming a rotatable sealing connection. The spindle 4 and the blind plate 31 are hollow, and the blind plate 31 has a storage space 30 for accommodating cooling water.

[0037] Combination Figure 6 As shown, the guide vanes 32 are hollow and rotatably connected to the blind plate 31 via a rotating shaft 34. The two ends of the rotating shaft 34 extend into the interior of the guide vanes 32 and the storage space 30, respectively. Bearings and sealing rings are installed between the rotating shaft 34 and the sidewall of the blind plate 31. Cooling water enters the main shaft 4 from the first cooling pipe 25 through the sleeve 42 and the connecting port 41, flows into the storage space 30 of the blind plate 31, and then flows through the rotating shaft 34 into the internal cavity of each guide vane 32. After absorbing heat, it is discharged through the second cooling pipe 26 at the bottom of the secondary reaction tower 2, forming a cooling water circulation loop.

[0038] The workflow of this application embodiment is as follows: The raw brine and calcium hydroxide solution to be purified enter the primary reactor 1 from the brine inlet and calcium hydroxide solution inlet at the top, respectively. A magnesium removal reaction occurs within the primary reactor 1, causing magnesium ions to precipitate as magnesium hydroxide. The primary reaction liquid is discharged from the first reaction liquid outlet and enters the upper part of the secondary reaction tower 2 via a connecting pipe from the first reaction liquid inlet 23.

[0039] Meanwhile, after being purged by a dust collector, the boiler flue gas enters the bottom of the secondary reaction tower 2 through the flue gas inlet 21. During the countercurrent contact process where the primary reaction liquid flows from top to bottom and the flue gas flows from bottom to top, the swirl plate 3 inside the secondary reaction tower 2 disperses the liquid into fine droplets. The carbon dioxide in the flue gas is absorbed by the liquid phase and reacts with calcium ions to form calcium carbonate precipitate.

[0040] During the reaction, cooling water is introduced through the first cooling pipe 25, flows through the main shaft 4 into the cavities inside the blind plates 31 and guide vanes 32 of each layer of swirl plates 3, absorbs the heat of reaction and the sensible heat of the flue gas, and is then discharged through the second cooling pipe 26. In some embodiments, the first cooling pipe 25 and the second cooling pipe 26 can also be connected to a heat recovery device to reuse the heat carried away.

[0041] The exhaust gas from the reaction is discharged from exhaust gas outlet 22, the secondary reaction liquid is discharged from the second reaction liquid outlet 24, and the calcium carbonate slurry is discharged from the second slurry outlet 27, entering the subsequent clarification and separation process. The apparatus of this embodiment is used to purify brine containing calcium and magnesium ions, with a processing capacity of 50 m³ / h and a liquid-to-gas ratio of 10 L / m³. The carbonation reaction time is significantly shortened compared to traditional clarification tanks; the concentration in the refined brine meets the requirements for salt production.

[0042] The apparatus in this embodiment uses a two-stage reaction tower 2 instead of a traditional clarifier tank for carbonization and calcium removal. The swirl plate 3 inside the tower disperses the liquid into fine droplets or a thin film, utilizing the kinetic energy of the gas itself to generate swirling motion, increasing the gas-liquid contact area and thus improving processing efficiency. By installing an adjustment component on the blind flange 31, the inclination angle of the guide vanes can be adjusted according to changes in flue gas flow rate and brine treatment volume, maintaining the operating gas velocity inside the tower within the optimal range. This design prevents scale buildup on the tower internals, effectively solving the problem of easy clogging in existing clarifier tanks.

[0043] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0044] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0045] Similarly, it should be understood that, in order to streamline this application and aid in understanding one or more of the various inventive aspects, features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, its inventive point lies in solving the corresponding technical problem with features fewer than all features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0046] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A lime flue gas brine purification device, characterized in that, The device includes: A primary reactor, wherein the upper part of the primary reactor is provided with a brine inlet and a calcium hydroxide solution inlet, and the bottom part is provided with a first reaction liquid outlet and a first mud outlet; A secondary reaction tower, which is a tower-type gas-liquid reaction device, is equipped with internal components for enhancing the gas-liquid contact and reaction between carbon dioxide gas and brine. The upper part of the secondary reaction tower is provided with a first reaction liquid inlet and a tail gas outlet, and the lower part of the secondary reaction tower is provided with a flue gas inlet, a second reaction liquid outlet, and a second slurry outlet. The internal components of the tower include a swirl plate, which includes a blind plate and guide vanes arranged circumferentially around the blind plate. The blind plate is rotatably mounted inside the secondary reaction tower via a main shaft, and the guide vanes are rotatably mounted on the blind plate. The blind plate is provided with an adjustment assembly for adjusting the angle of the guide vanes.

2. The lime flue gas brine purification device according to claim 1, characterized in that, The secondary reaction tower has multiple swirl plates arranged from top to bottom inside. An angle is formed between the guide vanes and the end face of the blind plate, and the inclination angle of the guide vanes on each swirl plate is different.

3. The lime flue gas brine purification device according to claim 2, characterized in that, A gap of 400-800 mm is left between two adjacent swirl plates.

4. The lime flue gas brine purification device according to claim 2, characterized in that, The guide vanes are rotatably mounted around the blind plate via a rotating shaft. An annular baffle is provided at the upper edge of the blind plate. The adjustment assembly includes an adjustment disk rotatably mounted inside the annular baffle. The adjustment disk corresponds one-to-one with the guide vanes. An adjustment rod is hinged between the adjustment disk and the guide vanes.

5. The lime flue gas brine purification device according to claim 4, characterized in that, An annular groove is provided on one side of the annular baffle, and an annular airbag strip is provided in the annular groove. A guide rod is provided on the outside of the airbag strip. The guide rod is slidably connected to the annular baffle and passes through the adjusting plate. A guide groove is provided on the guide rod. The guide groove is curved and the curvature is along the axial direction of the guide rod and bends in the circumferential direction. A locking block that cooperates with the guide groove is provided in the adjusting plate. The guide rod is used to drive the adjusting plate to rotate.

6. The lime flue gas brine purification device according to claim 5, characterized in that, An electric push rod is provided at the upper end of the blind plate. One end of the electric push rod is fixed to the blind plate, and the other end is connected to a movable rod. A piston is connected to the end of the movable rod. A sleeve is connected to the outside of the airbag strip. The sleeve and the airbag strip are in communication. The piston is movably installed in the sleeve.

7. The lime flue gas brine purification device according to claim 1, characterized in that, The main shaft is a hollow tube, and the main shaft and the blind plate are hollowly arranged. The blind plate has a storage space for accommodating cooling water. The top of the main shaft is connected to a first cooling pipe and is rotatably and sealed to the first cooling pipe. The bottom of the main shaft is rotatably and sealed to the bottom of the secondary reaction tower. The bottom of the secondary reaction tower is connected to a second cooling pipe.

8. The lime flue gas brine purification device according to claim 7, characterized in that, The guide vane is hollow and rotatably connected to the blind plate via a rotating shaft. The two ends of the rotating shaft extend into the interior of the guide vane and the storage space, respectively. A bearing and a sealing ring are provided between the rotating shaft and the side wall of the blind plate.

9. The lime flue gas brine purification device according to claim 1, characterized in that, The flue gas inlet is used to introduce boiler flue gas, which contains at least carbon dioxide gas, and the flue gas inlet is also connected to a dust collector.

10. The lime flue gas brine purification device according to claim 9, characterized in that, The flue gas inlet is also connected to the booster fan, which is used to supplement gas power when the flue gas flow in the boiler is insufficient.

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