Crystal slurry automatic recovery device

Abstract

This invention discloses an automatic crystal slurry recovery device, comprising a reaction tank, a sedimentation tank, a sedimentator, an air-lift crystal removal system, and a control system. The air-lift crystal removal system includes an air-lift pipe and a high-pressure gas supply device. The reaction tank has inlets and outlets at its front and rear ends. The air-lift pipe is inserted into the sedimentator from top to bottom, with its lower end extending to the bottom of the sedimentator. The high-pressure gas supply device provides high-pressure gas flowing upwards to the air-lift pipe. The upper end of the air-lift pipe is connected to a crystal collection device. The mixed liquid from the crystallization reaction in the reaction tank can enter the sedimentator through the inlet. The air-lift pipe can negatively adsorb and discharge large crystal particles deposited at the bottom of the sedimentator into the crystal collection device. The outlet at the rear end of the reaction tank is connected to the inlet of the sedimentation tank and sends the liquid from which large crystal particles have been removed into the sedimentation tank. The control system can control the operation of the high-pressure gas supply device. This invention avoids large crystal particles entering the sedimentation tank and avoids mechanical overload problems for the rear-end sludge scraper.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to an automatic crystal slurry recovery device. Background Technology

[0002] In treating fluoride-containing industrial wastewater, factories typically use slaked lime (Ca(OH)2) to remove fluoride. Calcium ions react with fluoride ions in the wastewater to produce calcium fluoride crystals (CaF2), which are then collected in a sedimentation tank for centralized disposal. In the crystallization process, methods such as increasing crystal reflux are commonly used to accelerate the crystallization rate and increase the crystal particle size. As the system operates, the crystal particle size gradually increases, and the proportion of large-diameter crystals continues to rise.

[0003] However, this phenomenon can severely impact the normal operation of the sludge scraper in the final sedimentation tank. When the scraper pushes sludge at the bottom of the tank, its drive shaft torque is primarily used to overcome the frictional resistance between the sludge and the scraper blades and the tank bottom. The accumulation of large crystal particles increases the roughness of the sludge layer, forming a denser bed, thereby increasing the interfacial friction coefficient between the scraper blades and the sludge. This directly leads to higher mechanical stress loads on the scraper drive motor torque, transmission shaft, and scraper arms.

[0004] Under prolonged high load, if the sludge scraper jams or stops, it will not only interrupt sludge discharge and cause excessive accumulation of crystals at the bottom of the tank, but may also cause the entire water treatment line to shut down due to equipment maintenance.

[0005] Currently, there are no effective methods or patents on the market to solve this problem. Therefore, there is an urgent need for a solution to the problems of continuously increasing crystal particle size and the continuous increase in the proportion of large crystal particles in fluoride-containing industrial wastewater treatment systems, which leads to increased load on sludge scrapers. Summary of the Invention

[0006] To overcome the above deficiencies, the present invention provides an automatic crystal slurry recovery device. This device can intercept and settle large crystal particles before the sedimentation tank and discharge them from the system in advance using a fluid conveying method, thereby avoiding the mechanical overload problem of the downstream sludge scraper and achieving a rapid response to loads such as increased torque of the sedimentation tank sludge scraper.

[0007] The technical solution adopted by this invention to solve its technical problem is: an automatic crystal slurry recovery device, including a reaction tank and a sedimentation tank, further including a sedimentator, an air-lift crystal removal system, and a control system. The air-lift crystal removal system includes an air-lift pipe and a high-pressure gas supply device. The front end of the reaction tank is provided with an inlet, and the rear end of the reaction tank is provided with an outlet. The air-lift pipe is inserted into the sedimentator from top to bottom, and the lower end of the air-lift pipe extends to the bottom of the sedimentator. The air-lift pipe is connected to the high-pressure gas supply device, which provides high-pressure gas flowing from bottom to top to the air-lift pipe. The upper end of the air-lift pipe is connected to a crystal collection device. The mixed liquid that has undergone crystallization reaction in the reaction tank can enter the sedimentator through the inlet. The air-lift pipe can negatively adsorb and discharge large crystal particles deposited at the bottom of the sedimentator into the crystal collection device. The outlet at the rear end of the reaction tank is connected to the inlet of the sedimentation tank and sends the liquid from which the large crystal particles have been removed into the sedimentation tank. The control system can control the operation of the high-pressure gas supply device.

[0008] As a further improvement of the present invention, a drain outlet is provided on the rear side wall of the reaction tank. The drain outlet is connected to the inlet of the sedimentation tank through a pipe. The sedimentator is located inside the reaction tank and is fixedly installed on the rear side wall of the reaction tank. The outlet of the sedimentator completely covers the drain outlet on the rear side wall of the reaction tank. The pre-precipitated liquid in the sedimentator can enter the sedimentation tank through its outlet and the drain outlet on the rear side wall of the reaction tank.

[0009] As a further improvement of the present invention, the sedimentation tank includes a front plate, a top plate, a bottom plate, a rear plate, and side plates. The front plate and the rear plate are arranged parallel to each other along the water flow direction. Two side plates are symmetrically arranged on the left and right sides of the front plate and the rear plate. The top plate and the bottom plate are respectively fixedly installed at the upper and lower ends of the square cylindrical structure surrounded by the front plate, the rear plate, and the two side plates. The upper side of the bottom plate is an inclined surface with the front end height higher than the rear end height. The inlet and outlet of the sedimentation tank are located on the front plate and the rear plate, respectively. The lower end of the air lift pipe is located above the rear end of the bottom plate, and the upper end of the air lift pipe extends out to the outside of the sedimentation tank through the first clearance hole on the top plate.

[0010] As a further improvement of the present invention, the sedimentation tank also includes a baffle plate, which is arranged parallel to and spaced apart from the front end plate. The left and right sides of the baffle plate are respectively fixedly connected to two side plates. The lower end of the baffle plate is lower than the lower edge of the water inlet on the front end plate. A water passage is formed between the baffle plate and the upper side of the bottom plate.

[0011] As a further improvement of the present invention, a baffle plate is also fixedly provided on the rear end plate. The baffle plate is fixedly connected to two side plates on the left and right sides respectively. The outlet of the sedimentation tank is located above the baffle plate. A water passage is formed between the front end of the baffle plate and the baffle plate. A second clearance hole through which the air supply pipe passes is also provided on the baffle plate.

[0012] As a further improvement of the present invention, the lower side of the baffle plate is an inclined surface with the front end height lower than the rear end height, the angle between the lower side of the baffle plate and the rear end plate is 30°~90°, the projection length of the baffle plate on the horizontal plane is 1 / 2~2 / 3 of the distance from the baffle plate to the rear end plate, and the upper edge of the baffle plate is located 5~30 cm below the water outlet.

[0013] As a further improvement of the present invention, the air lifting pipe is sealed to both the first clearance hole and the second clearance hole, and the horizontal distance between the lower end of the air lifting pipe and the rear end plate is about 5 cm, and the vertical distance between the lower end of the air lifting pipe and the lowest point of the bottom plate is 5 to 20 cm.

[0014] As a further improvement of the present invention, the lower edge of the baffle is lower than the connection seam between the front end plate and the bottom plate, and the vertical height difference between the lower end of the baffle and the lower end of the front end plate is 5 to 10 cm; the distance between the front end plate and the baffle is 1 / 3 to 1 / 2 of the distance between the front end plate and the rear end plate.

[0015] As a further improvement of the present invention, the angle between the upper side of the base plate and the front end plate is 120°~160°, and the angle between the upper side of the base plate and the rear end plate in cross-section is 20°~60°.

[0016] As a further improvement of the present invention, the water inlet on the front end plate and the water outlet on the rear end plate are the same size and their centers are at the same horizontal height.

[0017] The beneficial technical effects of this invention are as follows: By setting a settler between the reaction tank and the sedimentation tank, the liquid that has undergone the crystallization reaction in the reaction tank first enters the settler, allowing large crystal particles in the liquid to pre-sediment in the settler. This intercepts the large crystal particles before they enter the sedimentation tank, and the large crystal particles deposited at the bottom of the settler are precipitated and discharged from the system by the negative pressure suction of the air lift pipe. This avoids the large crystal particles from entering the sedimentation tank, thereby avoiding the mechanical overload problem of the downstream sludge scraper and enabling a rapid response to loads such as increased torque of the sludge scraper in the sedimentation tank. Attached Figure Description

[0018] Figure 1 This is a perspective view of the precipitator of the present invention;

[0019] Figure 2 This is a front view of the precipitator of the present invention;

[0020] Figure 3 for Figure 2 Sectional view along line AA;

[0021] Figure 4 This is a left view of the precipitator of the present invention;

[0022] Figure 5 This is a top view of the precipitator of the present invention;

[0023] Figure 6 This is a schematic diagram illustrating the structural principle of the present invention. Detailed Implementation

[0024] Example: An automatic crystal slurry recovery device includes a reaction tank 30 and a sedimentation tank 40, and further includes a sedimentation unit 10, an air-lift crystal removal system, and a control system. The air-lift crystal removal system includes an air-lift pipe 20 and a high-pressure gas supply device. The front end of the reaction tank is provided with an inlet 18, and the rear end of the reaction tank is provided with an outlet 19. The air-lift pipe 20 is inserted into the sedimentation unit 10 from top to bottom, and the lower end of the air-lift pipe 20 extends to the bottom of the sedimentation unit 10. The air-lift pipe 20 is connected to the high-pressure gas supply device, which supplies gas to the sedimentation unit. Pipe 20 provides high-pressure gas flowing from bottom to top. The upper end of the air lift pipe 20 is connected to the crystal collection device. The mixed liquid that has undergone crystallization reaction in the reaction tank 30 can enter the sedimentation tank 10 through the inlet 18. The air lift pipe 20 can negatively adsorb and discharge the large-particle crystals deposited at the bottom of the sedimentation tank 10 into the crystal collection device. The outlet 19 at the rear end of the reaction tank is connected to the liquid inlet of the sedimentation tank 40 and sends the liquid with large-particle crystals removed into the sedimentation tank 40. The control system can control the operation of the high-pressure gas supply device.

[0025] The mixed liquid that has undergone crystallization in reaction tank 30 first enters sedimentation tank 10. Large crystal particles in the mixed liquid settle to the bottom of sedimentation tank 10, and air lift pipe 20 is directly inserted into the crystal enrichment zone at the bottom of sedimentation tank 10. Its working principle is to use compressed air injected into air lift pipe 20 to form a gas-liquid mixed flow, thereby generating fluid lifting force to continuously or intermittently automatically pump the enriched crystal slurry out of the system and send it to sediment collection device for collection or post-treatment. After the large crystal particles are removed by sedimentation, the liquid is discharged from sedimentation tank 10 and enters sedimentation tank 40. Small crystal particles in the mixed liquid further settle in sedimentation tank 40. After the small crystal particles settle in sedimentation tank 40, they are scraped into the sludge discharge area of ​​sedimentation tank 40 by a sludge scraper for sludge discharge. Since there are no large crystal particles in sedimentation tank 40, the mechanical overload problem of the sludge scraper is avoided, and a rapid response is achieved to the load such as the increase in torque of the sludge scraper in sedimentation tank 40.

[0026] The reaction tank 30 has a drain outlet on its rear side wall, which is connected to the inlet of the sedimentation tank 40 through a pipe. The sedimentation tank 10 is located inside the reaction tank 30 and is fixedly installed on the rear side wall of the reaction tank 30. The outlet 19 at the rear end of the sedimentation tank 10 completely covers the drain outlet on the rear side wall of the reaction tank 30. The pre-sedied liquid in the sedimentation tank 10 can enter the sedimentation tank 40 through the outlet 19 at its rear end and the drain outlet on the rear side wall of the reaction tank 30.

[0027] The reaction tank 30 can be arranged in a sequential manner from front to back to form a primary reaction tank 30, a secondary reaction tank 30, a tertiary reaction tank 30, and a quaternary reaction tank 30. Adjacent reaction tanks 30 are connected by alternating vertical water passages, allowing liquid to flow sequentially through the primary, secondary, tertiary, and quaternary reaction tanks 30 for thorough reaction. The sedimentation tank 10 is fixedly installed on the inner rear wall of the quaternary reaction tank 30. The sedimentation tank 10 can be fixed and locked to the inner rear wall of the quaternary reaction tank 30 by means of connectors, or it can be welded to the quaternary reaction tank 30 by welding. On the inner wall of the rear end of the reaction tank 30, the mixed liquid that has undergone sufficient reaction in the four-stage reaction tank 30 first enters the sedimentation tank 10 for pre-sedimentation treatment, and then is discharged through the outlet 19 of the sedimentation tank 10 and the outlet of the reaction tank 30, and enters the sedimentation tank 40 for sedimentation treatment. The reaction tank is fixedly installed in the four-stage reaction tank 30 to save space. In addition, the reaction tank can also be set separately between the reaction tank 30 and the sedimentation tank 40, or on the inlet channel of the sedimentation tank 40. This is an equivalent replacement structure that can be easily conceived by those skilled in the art based on this patent, and it falls within the scope of protection of this patent.

[0028] The sedimentation tank 10 includes a front plate 11, a top plate 12, a bottom plate 13, a rear plate 14, and side plates 15. The front plate 11 and the rear plate 14 are arranged parallel to each other along the water flow direction. The two side plates 15 are symmetrically arranged on the left and right sides of the front plate 11 and the rear plate 14. The top plate 12 and the bottom plate 13 are respectively fixedly installed at the upper and lower ends of the square cylindrical structure surrounded by the front plate 11, the rear plate 14, and the two side plates 15. The upper side of the bottom plate 13 is an inclined surface with the front end height higher than the rear end height. The inlet 18 and the outlet 19 of the sedimentation tank 10 are located on the front plate 11 and the rear plate 14, respectively. The lower end of the air lift pipe 20 is located above the rear end of the bottom plate 13, and the upper end of the air lift pipe 20 extends out to the outside of the sedimentation tank 10 through the first clearance hole on the top plate 12. The sedimentation tank 10 is fixedly connected by the front plate 11, top plate 12, bottom plate 13, rear plate 14 and side plate 15 to form a shell structure. It is a flow channel with water inlet at the front and water outlet at the rear, and is directly installed at the water inlet channel of the main sedimentation tank 40 or the water outlet 19 of the front reaction tank 30. Preferably, the sedimentation tank 10 is a trapezoidal shape with a wider front and a narrower rear, which is conducive to smooth water flow and guidance of large crystal particles.

[0029] The sedimentation tank 10 also includes a baffle plate 16, which is parallel to and spaced apart from the front end plate 11. The left and right sides of the baffle plate 16 are fixedly connected to two side plates 15 respectively. The lower end of the baffle plate 16 is lower than the lower edge of the inlet 18 on the front end plate 11, and a water passage is formed between the baffle plate 16 and the upper side of the bottom plate 13. The baffle plate 16 is vertically arranged behind the front inlet 18, and its lower edge is lower than the inlet 18, forming an underwater barrier that forces the incoming water to flow downward, and the kinetic energy is rapidly reduced.

[0030] A crystal-blocking plate 17 is also fixedly installed on the rear end plate 14. The left and right sides of the crystal-blocking plate 17 are respectively fixedly connected to two side plates 15. The outlet 19 of the sedimentation tank 10 is located above the crystal-blocking plate 17. A water passage is formed between the front end of the crystal-blocking plate 17 and the baffle plate 16. The crystal-blocking plate 17 is also provided with a second clearance hole through which the air supply pipe 20 passes. The function of the crystal-blocking plate 17 is to block the settled crystals that move with the water flow towards the outlet and guide them back to the bottom collection area.

[0031] The lower side of the baffle plate 17 is an inclined surface with the front end height lower than the rear end height. The angle between the lower side of the baffle plate 17 and the rear end plate 14 is 30° to 90°. The projected length of the baffle plate 17 on the horizontal plane is 1 / 2 to 2 / 3 of the distance from the baffle plate 16 to the rear end plate 14. The upper edge of the baffle plate 17 is located 5 to 30 cm below the outlet 19. Inside the sedimentation tank 10, the baffle plate 16, set at a specific angle, and the inclined baffle plate 17 work together to efficiently rectify and decelerate the incoming water, allowing solid particles in the effluent to be rapidly pre-sedied and enriched.

[0032] The air lift pipe 20 is sealed to both the first and second clearance holes. The horizontal distance from the lower end of the air lift pipe 20 to the rear end plate 14 is approximately 5 cm, and the vertical distance from the lowest point of the bottom plate 13 is 5-20 cm. The air lift pipe 20 passes through the first and second clearance holes on the top plate 12 and the crystal baffle plate 17 in a sealed manner from top to bottom, with the lower end suction port precisely positioned near the lowest point of the bottom plate 13. When compressed air is introduced into the air lift pipe 20, the concentrated crystal slurry enriched therein can be automatically and continuously drawn out by utilizing the principle of generating lifting force due to the decrease in density of the gas-liquid mixture.

[0033] The lower edge of the baffle plate 16 is lower than the joint between the front end plate 11 and the bottom plate 13, and the vertical height difference between the lower end of the baffle plate 16 and the lower end of the front end plate 11 is 5 to 10 cm; the distance between the front end plate 11 and the baffle plate 16 is 1 / 3 to 1 / 2 of the distance between the front end plate 11 and the rear end plate 14.

[0034] The angle between the upper side of the bottom plate 13 and the front end plate 11 is 120°~160°, and the angle between the upper side of the bottom plate 13 and the rear end plate 14 in cross-section is 20°~60°. The bottom plate 1313 is designed as an inclined surface, and the angle range between it and the front and rear end plates 14 is as described above, which is intended to allow the settled crystal slurry to slide and converge towards the lowest point at the bottom (near the rear end) under the action of gravity.

[0035] The inlet 18 on the front end plate 11 and the outlet 19 on the rear end plate 14 are the same size and their centers are at the same horizontal height, which can ensure uniform water intake.

[0036] During installation, the settler 10 is fixed to the rear wall of the reaction tank 30 through the mounting holes on the rear end plate 14, ensuring that its inlet 18 is connected to the outlet of the reaction tank 30, and that the outlet 19 of the settler 10 completely covers the original outlet of the reaction tank 30, and that its own outlet 19 completely covers the original effluent channel of the reaction tank 30. The settler 10 is integrated into the existing system to perform pre-sedimentation and simultaneous crystal slurry recovery of the reaction effluent. Once installed, it ensures that all effluent from the reaction tank 30 is discharged through the settler 10. The high-pressure gas supply device of the air stripping crystal discharge system is connected to the control system, and the automatic control program of the control system controls the high-pressure gas supply device to start and stop at regular intervals according to the working conditions.

Claims

1. An automatic crystal slurry recovery device, comprising a reaction tank (30) and a sedimentation tank (40), characterized in that: It also includes a precipitator (10), a stripping crystal removal system, and a control system. The stripping crystal removal system includes a stripping pipe (20) and a high-pressure gas supply device. The front end of the reaction tank (30) is provided with an inlet (18), and the rear end of the reaction tank (30) is provided with an outlet (19). The stripping pipe (20) is inserted into the precipitator (10) from top to bottom, and the lower end of the stripping pipe (20) extends to the bottom of the precipitator (10). The stripping pipe (20) is connected to the high-pressure gas supply device, which provides gas to the stripping pipe (20). High-pressure gas is supplied from bottom to top. The upper end of the gas lift pipe (20) is connected to the crystal collection device. The mixed liquid that has undergone crystallization reaction in the reaction tank (30) can enter the sedimentation tank (10) through the water inlet. The gas lift pipe (20) can negatively adsorb the large particles of crystal deposited at the bottom of the sedimentation tank (10) and discharge them into the crystal collection device. The water outlet at the rear end of the reaction tank is connected to the liquid inlet of the sedimentation tank and sends the liquid that removes the large particles of crystal into the sedimentation tank (40). The control system can control the operation of the high-pressure gas supply device.

2. The automatic crystal slurry recovery device according to claim 1, characterized in that: The reaction tank (30) has a drain outlet on its rear side wall. The drain outlet is connected to the inlet of the sedimentation tank (40) through a pipe. The sedimentation tank (10) is located inside the reaction tank (30) and is fixedly installed on the rear side wall of the reaction tank (30). The outlet of the sedimentation tank (10) completely covers the drain outlet on the rear side wall of the reaction tank (30). The liquid that has been pre-precipitated in the sedimentation tank (10) can enter the sedimentation tank (40) through its outlet and the drain outlet on the rear side wall of the reaction tank (30).

3. The automatic crystal slurry recovery device according to claim 1, characterized in that: The sedimentation tank (10) includes a front plate (11), a top plate (12), a bottom plate (13), a rear plate (14), and a side plate (15). The front plate (11) and the rear plate (14) are arranged parallel to each other along the water flow direction. The two side plates are symmetrically arranged on the left and right sides of the front plate and the rear plate (14). The top plate (12) and the bottom plate (13) are respectively fixedly installed on the upper and lower ends of the square cylindrical structure surrounded by the front plate (11), the rear plate (14), and the two side plates (15). The upper side of the bottom plate (13) is an inclined surface with the front end height higher than the rear end height. The inlet and outlet of the sedimentation tank (10) are located on the front plate (11) and the rear plate (14), respectively. The lower end of the air lift pipe (20) is located above the rear end of the bottom plate. The upper end of the air lift pipe (20) extends out to the outside of the sedimentation tank (10) through the first clearance hole on the top plate.

4. The automatic crystal slurry recovery device according to claim 3, characterized in that: The sedimentation tank (10) also includes a baffle plate (16), which is parallel to and spaced apart from the front end plate (11). The left and right sides of the baffle plate (16) are fixedly connected to two side plates (15) respectively. The lower end of the baffle plate (16) is lower than the lower edge of the water inlet on the front end plate (11). A water passage is formed between the baffle plate (16) and the upper side of the bottom plate (13).

5. The automatic crystal slurry recovery device according to claim 4 is characterized in that: a baffle plate (17) is fixedly provided on the rear end plate, the baffle plate (17) is fixedly connected to two side plates (15) on the left and right sides respectively, the outlet of the sedimentation tank (10) is located above the baffle plate (17), a water passage is formed between the front end of the baffle plate (17) and the baffle plate (16), and a second clearance hole through which the air supply pipe passes is provided on the baffle plate (17).

6. The automatic crystal slurry recovery device according to claim 5, characterized in that: The lower side of the baffle plate (17) is an inclined surface with the front end height lower than the rear end height. The angle between the lower side of the baffle plate (17) and the rear end plate is 30°~90°. The projection length of the baffle plate (17) on the horizontal plane is 1 / 2~2 / 3 of the distance from the baffle plate (16) to the rear end plate (14). The upper edge of the baffle plate (17) is located 5~30 cm below the water outlet.

7. The automatic crystal slurry recovery device according to claim 5, characterized in that: The air lifting pipe is sealed to the first clearance hole and the second clearance hole. The horizontal distance between the lower end of the air lifting pipe (20) and the rear end plate (14) is about 5 cm, and the vertical distance between the lower end of the air lifting pipe (20) and the lowest point of the bottom plate (13) is 5-20 cm.

8. The automatic crystal slurry recovery device according to claim 4, characterized in that: The lower edge of the baffle plate (16) is lower than the joint between the front end plate (11) and the bottom plate (13), and the vertical height difference between the lower end of the baffle plate (16) and the lower end of the front end plate (11) is 5~10cm; the distance between the front end plate (11) and the baffle plate (16) is 1 / 3~1 / 2 of the distance between the front end plate and the rear end plate (14).

9. The automatic crystal slurry recovery device according to claim 3, characterized in that: The angle between the upper side of the base plate and the front end plate (11) is 120°~160°, and the angle between the upper side of the base plate (13) and the rear end plate (14) in cross-section is 20°~60°.

10. The automatic crystal slurry recovery device according to claim 4, characterized in that: The inlet (18) on the front end plate and the outlet (19) on the rear end plate (14) are the same size and their centers are at the same horizontal height.

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