An efficient fluorine crystal wastewater defluorination device

Abstract

The present invention provides an efficient fluorine crystal wastewater defluorination device, relating to the field of wastewater treatment. The efficient fluorine crystal wastewater defluorination device comprises a crystallization reaction tank, a seed crystal stirring tank, and a seed crystal silo, which are connected in sequence. The seed crystal stirring tank is provided with two water inlets. A tank cover is fixedly mounted on the upper end of the crystallization reaction tank. A drainage channel for drainage is provided inside the tank cover. The drainage end of the drainage channel is connected to a tee pipe A. One end of the tee pipe A is connected to one of the water inlets of the seed crystal stirring tank, and the other end is used for drainage. The efficient fluorine crystal wastewater defluorination device forms larger calcium fluoride crystals by adding fluorine crystals and precipitant calcium ions into the crystallization reaction tank. The calcium fluoride crystals are screened layer by layer to recover large calcium fluoride crystals. Small calcium fluoride crystals are returned to the crystallization reaction tank to continue to produce large calcium fluoride crystals. Sludge in the crystallization reaction tank is recovered, generating certain economic benefits and reducing operating costs.

Description

Technical Field

[0001] The invention relates to the field of wastewater treatment, in particular to a high-efficiency fluorine crystal defluorination device for wastewater. Background Art

[0002] Wastewater treatment refers to the use of physical, chemical and biological methods to treat wastewater to purify it and reduce pollution, so as to achieve the purpose of wastewater recovery and reuse, thereby making full use of water resources. This process includes four main methods: wastewater physical treatment, wastewater chemical treatment, wastewater physical and chemical treatment and wastewater biological treatment. The treatment of fluorine-containing wastewater faces many severe challenges, among which high treatment costs, the generation of large amounts of fluorine-containing sludge and subsequent disposal needs are particularly prominent.

[0003] In the treatment of fluorine-containing wastewater, from the perspective of treatment cost, the consumption of chemicals is large and the sludge production is large. The effluent water quality can be stabilized at 12-15 mg / L. If the environmental protection requirements are lower than this standard, complex treatment processes will be considered. In order to ensure that the treatment effect meets the emission standards, it may be necessary to introduce high-end treatment methods such as membrane separation technology. The purchase, installation and maintenance costs of related equipment are very expensive. Secondly, in the process of treating fluorine-containing wastewater, a large amount of fluorine-containing sludge will be produced. This is because common treatment methods such as chemical precipitation will cause fluoride ions to combine with added chemical agents to form precipitates, which in turn produce a large amount of sludge. These sludges are not only bulky, but also cannot be piled up or discarded at will because they contain harmful substances such as fluorine. In summary, the cost of treating fluorine-containing wastewater is high, the amount of fluorine-containing sludge produced is large, and the disposal cost is high. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a high-efficiency fluorine crystal wastewater defluorination device. By adding fluorine crystals and precipitant calcium ions into a crystallization reaction tank, larger-particle calcium fluoride crystals are formed. The calcium fluoride crystals are screened layer by layer, and the large-particle calcium fluoride crystals are recovered. The small-particle calcium fluoride crystals are returned to the crystallization reaction tank to continue to produce large-particle crystals. The sludge in the crystallization reaction tank is recovered, which produces certain economic benefits, reduces the amount of sludge disposal, and reduces operating costs.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: an efficient fluorine crystal wastewater defluorination device, comprising a crystallization reaction tank, a seed stirring tank and a seed silo connected in sequence, the seed stirring tank is provided with two water inlets, the upper end of the crystallization reaction tank is fixedly mounted with a tank cover, the interior of the tank cover is provided with a drainage channel for drainage, the drainage end of the drainage channel is connected with a tee pipe A, one end of the tee pipe A is connected to one of the water inlets of the seed stirring tank, and the other end is used for drainage, and the other water inlet of the seed stirring tank is used for injecting tap water.

[0006] The crystallization reaction tank includes an upper water collection area, a forced crystallization reaction area, a forced separation area, a bottom water inlet area, a collection area for collecting and circulating small particles, and a sludge area for recovering sludge, which are connected in sequence. The seed stirring tank transports the seeds to the forced separation area through the seed dosing pump and the connecting pipe A, which are used to react in the crystallization reaction tank and generate large-particle crystals. The crystals that have not formed large particles are circulated to the forced separation area through the conveying component between the forced separation area and the collection area to regenerate large-particle crystals. A sludge extraction pipe for regular sludge extraction is installed at the bottom of the sludge area, and new crystal-inducing carriers are added through the seed dosing pump.

[0007] Several cone-shaped filter plates for placing crystal seeds are fixedly installed inside the forced separation zone. Several protruding structures are set on the arc surface of each filter plate. A jacket for reducing pressure and cooling is fixedly installed on the inner wall of the forced crystallization reaction zone. The wastewater to be treated is preferentially transported to the jacket through the water inlet pipe. The water outlet of the jacket injects the wastewater with adjusted pH into the water collection area through the water inlet pipe. A two-way channel component for passing water, small-particle crystals and discharging large-particle crystals is rotatably installed inside the crystallization reaction tank. Several turbine blades for generating vortices are fixedly installed at the bottom end of the two-way channel component. A screening net with a cone-shaped upper end and a ring-shaped bottom end is fixedly installed on the inner wall of the collection area.

[0008] Preferably, the seed crystal stirring tank includes a tank body and a seed crystal stirrer for stirring the seed crystals. The seed crystal stirrer is fixed to the tank body, and the tank body is supported by a bracket A.

[0009] Preferably, a scraper for scraping off sludge is installed at the bottom of the sludge area.

[0010] Preferably, an annular delivery pipe for increasing the delivery range is fixedly installed on the inner wall of the forced separation zone, and a two-way pipe is provided at one end of the connecting pipe A, one end of the two-way pipe is connected to the annular delivery pipe.

[0011] Preferably, a pH online meter is installed in the middle of the water inlet pipe, and the pH of the inlet water is kept within the required range by adding acid and alkali reagents at the front. There is also a pH online meter on the three-way pipe A.

[0012] Preferably, the reagents added to the crystallization reaction tank are fluorine crystals and precipitant calcium ions.

[0013] Preferably, the reagents added to the crystallization reaction tank are fluorine crystals and precipitant calcium ions.

[0014] Preferably, the substances transported to the forced separation zone by the seed crystal dosing pump and the connecting pipe A include fluorine crystals and precipitant calcium ions.

[0015] Preferably, the two-way channel assembly includes a rotating rod located between multiple filter plates, a grille fixed to the crystallization reaction tank, a filter cartridge fixed to the grille, a spiral blade fixed to the filter cartridge and a plurality of stirring blades fixed to the rotating rod, a plurality of screening holes are provided inside the spiral blade, the stirring blade is arranged to be curved and inclined, and gradually widens from the center axis outward, and the edge is arranged to be serrated, the spiral blade is fixedly connected to the rotating rod, the upper end of the filter cartridge is conical, the bottom end is cylindrical, and a plurality of filter holes are provided inside for separating small particle crystals, the rotating rod passes through the drainage channel and is connected to the external motor B.

[0016] Preferably, the conveying assembly includes a water pump and two pipes B connected to the water pump, wherein one pipe B is connected to the collection area, and the other pipe B is connected to the forced separation area.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. This efficient fluorine crystal wastewater defluoridation device adjusts the pH value of the influent before the crystallization reaction tank, and adds fluorine crystals and precipitant calcium ions. Relying on the unique internal component design of the crystallization reaction tank, the generated calcium fluoride precipitates in the fluidized state in the crystallization reaction tank, enriches and grows on the surface of the fluorine crystals, and forms larger particles of calcium fluoride crystals. The calcium fluoride crystals are discharged through the mud suction pipe at the bottom of the crystallization reaction tank. After layer-by-layer screening, large particles of calcium fluoride crystals are recovered, and small particles return to the crystallization reaction tank to continue to produce large particles of crystals. Through the set sheath, the wastewater enters the sheath first. The sheath is used not only for pressure reduction but also for temperature reduction. When the pressure is reduced, it is used to increase the water flow rate in the crystallization reaction tank. It is controlled within an appropriate range so that large particles of crystals overcome the water flow and slowly sink. By setting a two-way channel component, the spiral blades transport large and small particles of crystals downward. Large particles of crystals enter the sludge area, and small particles of crystals enter the collection area along the filter holes in the filter cartridge, and the other part enters the forced separation area along the forced crystallization reaction area. The water in the collection area is recirculated to the forced separation area through the conveying component to continue to produce large particles of crystals. Since the crystallization reaction tank has removed most of the fluoride ions in the wastewater, the amount of sludge is greatly reduced. The large-particle calcium fluoride sludge in the crystallization reaction tank has low water content and high purity and can be recycled, which produces certain economic benefits and reduces operating costs.

[0019] 2. This efficient fluorine crystal wastewater defluorination device further reduces fluoride ions by adding defluoridating agents and flocculants to meet emission standards. A sludge extraction pipe for regular sludge extraction is installed at the bottom of the sludge area. The sludge extraction pipe is connected to an external sludge extraction pump to transport the sludge out. New crystal-inducing carriers are added through the crystal seed dosing pump to maintain the particle concentration in the reactor and ensure the water output effect.

[0020] 3. The efficient fluorine crystal wastewater defluorination device is provided with a plurality of cone-shaped filter plates fixedly installed inside the forced separation zone for placing crystal seeds. The arc surface of each filter plate is provided with a plurality of protrusion structures, which not only increases the attachment area of ​​the crystal seeds, but also improves the adhesion of the crystal seeds. By setting the upper end of the screening net in a cone shape and the bottom end in a ring shape, the bottom end of the screening net is provided with an opening for passing large-particle crystals, so that the large-particle crystals enter the sludge area through the opening, and the small-particle crystals and sewage enter the water collection area through the screening net, which facilitates the circulation of small-particle crystals to the forced separation zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 It is a rear view of the overall structure of the present invention;

[0023] Figure 3 It is a cross-sectional view of the side view of the crystallization reaction tank of the present invention;

[0024] Figure 4 It is a cross-sectional view of the front view of the crystallization reaction tank of the present invention;

[0025] Figure 5 A top view of the filter plate of the present invention;

[0026] Figure 6 It is a structural schematic diagram of the grille and filter cartridge of the present invention;

[0027] Figure 7 A cross-sectional view of a schematic structural diagram of an overflow weir and a tank cover of the present invention;

[0028] Figure 8 It is a schematic diagram of the process of the present invention.

[0029] Among them: 1. Crystallization reaction tank; 2. Seed stirring tank; 3. Seed silo; 4. Drainage channel; 5. Tee pipe A; 6. Upper water collection area; 7. Forced crystallization reaction area; 8. Forced separation area; 9. Bottom water inlet area; 10. Collection area; 11. Sludge area; 12. Mud suction pipe; 13. Filter plate; 14. Sheath; 15. Two-way channel assembly; 151. Rotating rod; 152. Grille; 153. Filter cartridge; 154. Spiral blade; 155. Stirring blade; 156. Filter hole; 16. Turbine blade; 17. Screening net; 18. Sludge scraper; 19. Annular delivery pipe; 20. PH online meter; 21. Dosing box; 22. Valve; 23. Conveying assembly; 24. Water inlet pipe; 25. Water inlet pipe. DETAILED DESCRIPTION

[0030] Example 1:

[0031] like Figure 1-Figure 7As shown, an efficient fluorine crystal wastewater defluorination device comprises a crystallization reaction tank 1, a crystal seed stirring tank 2 and a crystal seed silo 3 which are connected in sequence. The crystal seed stirring tank 2 is provided with two water inlets. The fluorine crystals and precipitant calcium ions in the crystal seed silo 3 are transported to the crystal seed stirring tank 2 through a pump body and two pipes A. The crystal seed stirring tank 2 comprises a tank body and a crystal seed stirrer for stirring the crystal seeds. The crystal seed stirrer is fixed to the tank body, and the tank body is supported by a bracket A. Stirring can affect the growth direction and morphology of the crystals. Appropriate stirring speed and method can control the growth rate of the crystals, thereby affecting the size, shape and internal structure of the crystals. The reagents added to the crystallization reaction tank 1 are fluorine crystals and precipitant calcium ions. Fluorine ions and calcium ions precipitate and grow on the surface of the fluorine crystals to form a more Large-particle calcium fluoride crystallization, a tank cover 26 is fixedly installed on the upper end of the crystallization reaction tank 1, and a drainage channel 4 for drainage is opened inside the tank cover 26. The drainage end of the drainage channel 4 is connected with a tee pipe A5. One end of the tee pipe A5 is connected to one of the water inlets of the seed crystal stirring tank 2, which is used to replenish the water source required by the seed crystal stirring tank 2. The other end is used for drainage and is installed with a valve 22. The other water inlet of the seed crystal stirring tank 2 is used to inject tap water, which is used as the water source for replenishing the system when the system water outlet cannot be used as the water source for replenishing the seed crystal. The crystallization reaction tank 1 is connected to the dosing box 21 through a dosing pump and a dosing pipe, and the defluorinating agent and flocculant are added to the forced separation zone 8 and the forced crystallization reaction zone 7 in the crystallization reaction tank 1 to further reduce fluoride ions and meet the emission standards.

[0032] The crystallization reaction tank 1 includes an upper water collection area 6, a forced crystallization reaction area 7, a forced separation area 8, a bottom water inlet area 9, a collection area 10 for collecting small particles and circulating them, and a sludge area 11 for recovering sludge, which are connected in sequence. A scraper 18 for scraping sludge is installed at the bottom of the sludge area 11. The scraper 18 includes a motor A, a rotating shaft and a plurality of scraper plates. The motor A is fixedly installed at the bottom of the crystallization reaction tank 1, one end of the rotating shaft is fixedly connected to the two scraper plates, and the other end is fixedly connected to the output shaft of the motor A. The rotating shaft and the scraper plates are driven to rotate by the motor A to realize the sludge scraping work of the sludge area 11 at the bottom of the crystallization reaction tank 1. An annular delivery pipe 19 for increasing the delivery range is fixedly installed on the inner wall of the forced separation area 8. A two-way pipe is set at one end of the connecting pipe A, and one end of the two-way pipe is connected to the annular delivery pipe 19. The connecting pipe A is used to Seeds are fed into an annular feeding pipe 19, and the crystal seeds are fed to a plurality of filter plates 13 through the annular feeding pipe 19. The crystal seeds are transported to the forced separation zone 8 by the crystal seed feeding pump and the connecting pipe A in the crystal seed stirring tank 2 for reacting in the crystallization reaction tank 1 and generating large-particle crystals. The crystals that have not formed large particles are circulated to the forced separation zone 8 by the conveying component 23 between the forced separation zone 8 and the collection zone 10 to regenerate large-particle crystals. A sludge extraction pipe 12 for regular sludge extraction is installed at the bottom end of the sludge zone 11. The sludge extraction pipe 12 is connected to an external sludge extraction pump and transports the sludge out. New crystal inducing carriers are added through the crystal seed feeding pump to maintain the particle concentration in the reactor and ensure the water discharge effect. The substances transported to the forced separation zone 8 by the crystal seed feeding pump and the connecting pipe A include fluorine crystals and precipitant calcium ions. The fluorine ions and calcium ions precipitate and grow on the surface of the fluorine crystals to form larger-particle calcium fluoride crystals.

[0033] The forced separation zone 8 is internally fixed with a number of filter plates 13 that form a cone shape and are used to place crystal seeds. The arc surface of each filter plate 13 is provided with a number of convex structures, which not only increases the attachment area of ​​the crystal seeds, but also improves the adhesion of the crystal seeds. The inner wall of the forced crystallization reaction zone 7 is fixedly installed with a sheath 14 for reducing pressure and cooling. The wastewater to be treated is preferentially transported to the sheath 14 through the water inlet pipe 24. The outlet end of the sheath 14 injects the wastewater after adjusting the pH into the water collection area through the water inlet pipe 25. A pH online meter 20 is installed in the middle of the water inlet pipe 25 for detecting the pH of the water inlet. By adding acid and alkali reagents at the front, To keep the pH of the inlet water within the required range, there is also a pH online meter 20 on the three-way pipe A5 for monitoring the pH of the crystallization reaction tank 1. During the crystallization process, a specific pH range significantly improves the crystallization efficiency. The interior of the crystallization reaction tank 1 is rotatably installed with a two-way channel assembly 15 for passing water, small particle crystals and for discharging large particle crystals. The two-way channel assembly 15 includes a rotating rod 151 located between multiple filter plates 13, a grille 152 fixed to the crystallization reaction tank 1, a filter cartridge 153 fixed to the grille 152, a spiral blade 154 fixed to the filter cartridge 153, and a plurality of spiral blades 154 fixed to the rotating rod 151. The stirring blade 155 and the spiral blade 154 are provided with a plurality of screening holes inside. The stirring blade 155 is set to be curved and inclined, and gradually widens from the central axis outward. When rotating forward, it pushes the solution to flow like a propeller, which is easy to generate a vortex. The edge is set to be serrated to increase the contact area with water and further improve the stirring efficiency. The spiral blade 154 is fixedly connected to the rotating rod 151. The upper end of the filter cartridge 153 is conical and the bottom end is cylindrical. There are multiple filter holes 156 for separating small particle crystals inside. The rotating rod 151 passes through the drainage channel 4 and the tank cover 26 and is connected to the external motor B. The movable rod 151 is rotatably connected to the tank cover 26, and a seal is provided at the intersection of the rotating rod 151 and the tank cover 26. The conveying assembly 23 includes a water pump and two pipes B connected to the water pump, one of which is connected to the collection area 10, and the other is connected to the forced separation area 8. A plurality of turbine blades 16 for generating vortices are fixedly installed at the bottom end of the two-way channel assembly 15, and a screening mesh 17 with a conical upper end and a ring-shaped bottom end is fixedly installed on the inner wall of the collection area 10. The bottom end of the screening mesh 17 is provided with an opening for passing large particle crystals. The collection area 10 and the screening mesh 17 are both located in the bottom water inlet area 9.

[0034] When using, such as Figure 1-Figure 7As shown, first, the waste water to be treated is injected into the jacket 14 through the water inlet pipe 24, and the water in the jacket 14 enters the water collection area at the bottom of the crystallization reaction tank 1 along the water inlet pipe 25. The water in the water collection area rises along the crystallization reaction tank 1 and passes through the forced crystallization reaction area 7, the forced separation area 8 and the upper water collection area 6 in sequence. At this time, the fluorine crystals and precipitant calcium ions in the seed crystal silo 3 are transported to the seed crystal stirring tank 2 through the pump body and two pipes A, and the external tap water is injected into the seed crystal stirring tank 2 through one of the water inlets of the seed crystal stirring tank 2, and is stirred by the seed crystal stirrer. The crystals after stirring The fluorine crystals and the precipitant calcium ions are transported to the forced separation zone 8 through the seed crystal dosing pump and the connecting pipe A. Some of the fluorine ions and calcium ions from the connecting pipe A enter the forced separation zone 8, and the other part enters the annular tube and falls on multiple filter plates 13. The filter plates 13 cooperate with the convex structure at the filter plates 13 to increase the attachment area of ​​the crystal seeds and improve the adhesion of the crystal seeds. The fluorine ions and calcium ions precipitate and grow on the surface of the fluorine crystals to form larger particles of calcium fluoride crystals. The calcium fluoride crystals descend along the filter plates 13 and fall into the filter cartridge 153. Then, the rotating rod 151 is driven by an external motor to rotate. The movable rod 151 drives the filter cartridge 153, the spiral blade 154, the stirring blade 155 and the turbine blade 16 to rotate. When the stirring blade 155 rotates, it is used to stir the forced separation zone 8. The stirring blade 155 is set to be curved and inclined, and gradually widens from the central axis to the outside. When rotating forward, it pushes the solution to flow like a propeller, which is easy to generate a vortex, not only making the crystals easy to sink, but also the edge is set to be serrated to improve the gripping force and promote the mixing and crystallization process of the solution. When reversing, the stirring is accelerated, the contact area with the water is increased, and the stirring efficiency is further improved, thereby improving the crystallization. Efficiency and quality. It should be noted that when adding crystal seeds, the defluoridating agent and flocculant that are fully mixed in the dosing box 21 are added to the forced separation zone 8 and the forced crystallization reaction zone 7 in the crystallization reaction tank 1 through the dosing pump and the dosing pipe to further reduce the fluoride ions to meet the emission standards. In addition, the raw water in the water collection area needs to pass through an external hydraulic mixer and be mixed with chemicals. After the particles in the water reach the micro-destabilization condition, they enter the crystallization reaction tank 1 from the bottom. The organic polymer flocculant addition point is set at the end of the bottom water inlet pipe 24, and the hydraulic conditions of the inverted cone-shaped expansion section at the bottom of the bottom water inlet area 9 are used to achieve sufficient mixing.

[0035] Then, the large particle crystals generated from the forced separation zone 8 sink into the filter cartridge 153, and the spiral blades 154 drive the crystals to sink quickly. Under the action of gravity, the particles pass through the forced separation zone 8 and the forced crystallization reaction zone 7 into the sludge zone 11, thereby achieving the purpose of sludge concentration. When the filter cartridge 153 rotates, the small particle crystals pass through the filter holes 156 and are thrown into the forced crystallization reaction zone 7. The upper end of the screening net 17 is conical and the bottom end is ring-shaped. The bottom end of the screening net 17 is provided with an opening for passing large particle crystals, so that the large particle crystals enter the sludge zone 11 through the opening, and the small particle crystals and sewage pass through the screening net 17 into the water collection area and return to the forced separation zone 8 through the conveying component 23 to continue to generate large particles. Crystallization, when the turbine blades 16 rotate, a vortex is generated, and the fine particles generate strong vertical vortices with the high-speed water flow, which strengthens the solid-liquid separation, and reaches a dynamic equilibrium state under the action of hydraulic shear, so that the crystals always maintain the most compact structure during the growth process, thereby improving the traditional random flocculation process into a regular particle growth process, forming stable and dense crystalline particles. It should be noted that the diameter of the water inlet pipe 24 should be smaller than the diameter of the water inlet pipe 25, and a refrigerator needs to be installed in the jacket 14. When the water entering the water inlet pipe 24 enters the jacket 14 and is discharged from the water inlet pipe 25, the water flow is reduced. Through the cooling of the jacket 14, it is beneficial to force the crystals in the crystallization reaction zone 7 to form large particles, shortening the time for producing large particles.

[0036] Then, as mentioned above and Figure 8 The overall process is that the wastewater enters the crystallization reaction tank 1 through the external collection pool lifting pump and flow meter, the small particle crystals return to the forced reaction zone, the large particle crystals in the forced crystallization reaction zone 7 enter the sludge area 11, and the sludge is discharged through the sludge suction pipe 12 and entrusted to be transported outside. Part of the water discharged from the drainage channel 4 enters the crystal seed stirring tank 2, and the other part is discharged. It should be noted that when discharging sludge, a crystal seed dosing pump is required to inject crystal seeds into the crystallization reaction tank 1, and by adding new crystal inducing carriers, the particle concentration in the reactor is maintained to ensure the water output effect.

[0037] Example 2:

[0038] like Figure 7 As shown, the interior of the tank cover 26 is a hollow structure, and an overflow weir 27 is installed at the bottom. The water in the upper water collection area 6 enters the overflow weir 27 and is discharged into the three-way pipe A5 through the drainage end of the tank cover 26. The overflow weir 27 is used to control the uniform outflow of water.

[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An efficient fluorine crystal elimination wastewater defluorination device, comprising a crystallization reaction tank (1), a seed crystal stirring tank (2) and a seed crystal silo (3) connected in sequence, wherein the seed crystal stirring tank (2) is provided with two water inlets, a tank cover (26) is fixedly mounted on the upper end of the crystallization reaction tank (1), a drainage channel (4) for drainage is provided inside the tank cover (26), a drainage end of the drainage channel (4) is connected to a tee pipe A (5), one end of the tee pipe A (5) is connected to one of the water inlets of the seed crystal stirring tank (2), and the other end is used for drainage, and the other water inlet of the seed crystal stirring tank (2) is used for injecting tap water; The crystallization reaction tank (1) comprises an upper water collection area (6), a forced crystallization reaction area (7), a forced separation area (8), a bottom water inlet area (9), a collection area (10) for collecting and circulating small particles, and a sludge area (11) for recovering sludge, which are connected in sequence. The seed stirring tank (2) transports the seed crystals to the forced separation area (8) through a seed crystal dosing pump and a connecting pipe A, so as to react in the crystallization reaction tank (1) and generate large-particle crystals. The crystals that have not formed large particles are circulated to the forced separation area (8) through a transport component (23) between the forced separation area (8) and the collection area (10) to regenerate large-particle crystals. A sludge extraction pipe (12) for periodically extracting sludge is installed at the bottom end of the sludge area (11), and new crystal-inducing carriers are added through the seed crystal dosing pump. A plurality of filter plates (13) in a cone shape and used for placing crystal seeds are fixedly installed inside the forced separation zone (8), and a plurality of protruding structures are provided on the arc surface of each filter plate (13). A jacket (14) for reducing pressure and cooling is fixedly installed on the inner wall of the forced crystallization reaction zone (7). The wastewater to be treated is preferentially transported into the jacket (14) through the water inlet pipe (24). The water outlet of the jacket (14) injects the wastewater after adjusting pH into the water collection area through the water inlet pipe (25). A two-way channel component (15) for passing water, small particle crystals and discharging large particle crystals is rotatably installed inside the crystallization reaction tank (1). A plurality of turbine blades (16) for generating vortices are fixedly installed at the bottom end of the two-way channel component (15). A screening net (17) with a cone-shaped upper end and a ring-shaped bottom end is fixedly installed on the inner wall of the collection zone (10).

2. The efficient fluorine crystal defluorination device for wastewater according to claim 1, characterized in that: The seed crystal stirring tank (2) comprises a tank body and a seed crystal stirrer for stirring seed crystals. The seed crystal stirrer is fixed to the tank body, and the tank body is supported by a bracket A.

3. The efficient fluorine crystal defluorination device for wastewater according to claim 1 is characterized in that: A scraper (18) for scraping off sludge is installed at the bottom of the sludge area (11).

4. The efficient fluorine crystal defluorination device for wastewater according to claim 1, characterized in that: An annular delivery pipe (19) for increasing the delivery range is fixedly installed on the inner wall of the forced separation zone (8); a two-way pipe is provided at one end of the connecting pipe A, one end of the two-way pipe is communicated with the annular delivery pipe (19).

5. The efficient fluorine crystal defluorination device for wastewater according to claim 1, characterized in that: A pH online meter (20) is installed in the middle of the water inlet pipe (25) for detecting the pH of the inlet water. By adding acid and alkali reagents at the front, the pH of the inlet water is kept within the required range. A pH online meter (20) is also installed on the three-way pipe A (5) for monitoring the pH of the crystallization reaction tank (1).

6. The efficient fluorine crystal defluorination device for wastewater according to claim 1, characterized in that: The reagents added to the crystallization reaction tank (1) are fluorine crystals and precipitant calcium ions.

7. The efficient fluorine crystal defluorination device for wastewater according to claim 1, characterized in that: The crystallization reaction tank (1) is connected to a dosing box (21) via a dosing pump and a dosing pipe, and the defluorinating agent and flocculant are added to the forced separation zone (8) and the forced crystallization reaction zone (7) in the crystallization reaction tank (1).

8. The efficient fluorine crystal defluorination device for wastewater according to claim 1, characterized in that: The substances transported to the forced separation zone (8) by the seed crystal dosing pump and the connecting pipe A include fluorine crystals and precipitant calcium ions.

9. The efficient fluorine crystal defluorination device for wastewater according to claim 1, characterized in that: The bidirectional channel assembly (15) comprises a rotating rod (151) located between a plurality of filter plates (13), a grille (152) fixed to the crystallization reaction tank (1), a filter cartridge (153) fixed to the grille (152), a spiral blade (154) fixed to the filter cartridge (153), and a plurality of stirring blades (155) fixed to the rotating rod (151). The spiral blade (154) is provided with a plurality of screening holes inside. The stirring blade (155) is arranged in a curved and inclined shape and gradually widens from the central axis outward. The edge is arranged in a serrated shape. The spiral blade (154) is fixedly connected to the rotating rod (151). The upper end of the filter cartridge (153) is conical and the lower end is cylindrical. A plurality of filter holes (156) for separating small particle crystals are provided inside. The rotating rod (151) passes through the drainage channel (4) and is connected to the external motor B.

10. The efficient fluorine crystal defluorination device for wastewater according to claim 6, characterized in that: The conveying assembly (23) comprises a water pump and two pipes B connected to the water pump, wherein one pipe B is connected to the collection area, and the other pipe B is connected to the forced separation area (8).

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