A wastewater forced circulation fractional crystallization reactor

Abstract

The application relates to a wastewater forced circulation grading crystallization reactor, which comprises a reaction body, the reaction body comprises, from top to bottom, a water outlet, a separator, a swing web, a crystallization granulation zone and a grading chamber, the side of the crystallization granulation zone is connected with a water inlet pipe and a dosing pipe, the bottom is provided with a separation plate with a small upper part and a large lower part; the grading chamber is provided with a disturbance device for disturbing the solid particles in the grading chamber, so that small particle solids float up and large particle solids sink down; the outside of the reaction body is provided with a forced circulation device, the forced circulation device comprises a suction pipe, a high-pressure pump, a drainage pipe and a plurality of parallel booster rings which are connected in sequence; the suction pipe is connected with the middle and upper part of the grading chamber and is used for sucking out small particle solids in the grading chamber; the drainage pipe is connected with the plurality of booster rings in parallel, the booster rings are arranged at least below the separator, below the swing web and in the crystallization granulation zone, and the upper surface and the lower surface of the booster ring are uniformly provided with a plurality of nozzles.

Description

Technical Field

[0001] This invention belongs to the field of wastewater crystallization treatment technology, specifically relating to a staged crystallization reactor for forced wastewater circulation. Background Technology

[0002] Currently, the treatment technology for saline wastewater combines crystallization precipitation with membrane treatment. Crystallization precipitation involves adding chemical agents to the wastewater to reduce the concentration of calcium in the water. 2+ The plasma undergoes a chemical reaction, generating crystals that then precipitate, simultaneously reducing wastewater turbidity and COD without producing byproducts. In particular, the CaCO3 particles can be recycled as a desulfurizing agent. This technology does not generate cleaning wastewater or cause wastewater recirculation, thus not increasing the system's treatment load. The precipitated water can undergo mud-water separation, and the resulting clarified liquid can be discharged for further membrane treatment, mitigating the risk of membrane system fouling.

[0003] The existing crystallization reactor has the following disadvantages: (1) During crystallization and granulation, solid particles are prone to agglomeration, which can lead to adhesion, caking, or scaling, which can easily block the separation device and affect the solid-liquid separation effect between the water and solid particles after the reaction. In addition, when crystals agglomerate and caking at the top of the reactor, it will affect the sedimentation of particles and cause poor fluidization effect in the reaction zone below, resulting in low effluent efficiency and poor effect; (2) The solid particles formed by crystallization have large differences in particle size, with many fine particles. However, the use of desulfurizing agent has strict requirements on the particle size of CaCO3, otherwise it will seriously affect the yield of good desulfurizing agent. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a graded crystallization reactor for forced wastewater circulation. This reactor performs crystallization and granulation softening treatment on wastewater, improving the fluidization effect of the wastewater, grading the particle size of the granulated particles, reducing the adverse effects of crystal agglomeration and caking on the separation device, improving the solid-liquid separation effect and the sedimentation efficiency of the granulated particles, and essentially producing no sludge or waste liquid.

[0005] The wastewater forced circulation staged crystallization reactor includes a reaction body, which from top to bottom includes an outlet, a separator, a swinging plate, a crystallization granulation zone, and a classification chamber. The crystallization granulation zone is connected to an inlet pipe and a dosing pipe on its side, and a separation plate with a smaller upper part and a larger lower part is provided at the bottom. The classification chamber is equipped with a disturbance device to disturb the solid particles in the classification chamber, so that small solid particles float to the top and large solid particles sink to the bottom.

[0006] The reaction body is equipped with a forced circulation device, which includes a suction pipe, a high-pressure pump, a drain pipe, and several parallel pressurizing rings connected in sequence. The suction pipe is connected to the upper middle part of the classification chamber and is used to suction out small particulate solids in the classification chamber. The drain pipe is connected in parallel with several pressurizing rings, which are located at least below the separator, below the swinging radii, and in the crystallization granulation zone. Several nozzles are uniformly arranged on the upper and lower surfaces of the pressurizing rings to spray out the small particulate solids extracted from the classification chamber.

[0007] The reactor of this invention features a classification chamber located below the crystallization and granulation zone. This chamber agitates the crystal particles, causing smaller solid particles to descend slowly and larger solid particles to descend quickly during the fall, resulting in natural stratification and achieving solid particle classification. The suction pipe extracts the smaller solid particles from the upper layer and forces them back into the upper middle part of the reaction body, serving as seed crystals and improving crystallization and growth efficiency. Furthermore, the pressure ring, under the action of a high-pressure pump, ejects the smaller solid particles from the nozzle, forming a jet containing solids. This jet impacts and breaks down crystal scale or deposits on the lower surface of the separator and the upper and lower surfaces of the oscillating plates, improving solid-liquid separation efficiency. The crystal scale or deposits fall into the crystallization and granulation zone, serving as seed crystals, or directly settle into the classification chamber.

[0008] Optionally, the separator includes several layers of first filter screens stacked one on top of the other. The first filter screens are wavy, and the troughs of adjacent first filter screens correspond to each other, that is, the trough of the upper first filter screen sinks into the trough of the lower first filter screen, and the peak of the lower first filter screen sinks into the peak of the upper first filter screen.

[0009] Alternatively, the mesh size of the several layers of the first filter screen decreases from bottom to top;

[0010] The external part of the reaction body is provided with several vibrators corresponding to the position of the separator. Each vibrator is connected to a first filter screen and is used to vibrate the first filter screen.

[0011] Optionally, the oscillating spokes include several oscillating blades, a connecting shaft, a frame, and an oscillating mechanism. The frame is fixed to the inner wall of the reaction body. The several oscillating blades are parallel to each other and their two ends are rotatably connected to the inner side of the frame. For example, the center horizontal line of the oscillating blades extends and rotatably connects to the inner side of the frame to facilitate the oscillation of the oscillating blades. The connecting shaft is a thin steel wire that passes through the center of each oscillating blade.

[0012] The swing mechanism includes an upper swing arm, a lower swing arm, a first hydraulic cylinder, and a second hydraulic cylinder. Both the first and second hydraulic cylinders are located outside the reaction body and are connected to the upper and lower swing arms respectively through their respective hydraulic rods. The upper and lower swing arms penetrate horizontally into the reaction body. The upper swing arm is connected to the upper end of each swing blade, and the lower swing arm is connected to the lower end of each swing blade.

[0013] Optionally, the booster ring is in the form of a spiral coil. The upper surface of the booster ring is provided with three nozzles, which are respectively located at the center of the upper surface and near the two side edges. Each nozzle is evenly provided with several nozzles. The nozzle of the central nozzle is vertically upward, and the nozzles of the two side nozzles are inclined to the sides respectively.

[0014] The lower surface of the booster ring is provided with three nozzles, located at the center and near the two side edges of the lower surface. Each nozzle is evenly provided with several nozzles. The nozzle of the central nozzle on the lower surface is vertically downward, while the nozzles of the two side nozzles on the lower surface are inclined to the sides, so that the spray direction of the nozzles on the upper and lower surfaces is far away from the vertical direction of the central nozzle.

[0015] Each nozzle is evenly distributed along the spiral direction of the booster ring.

[0016] Optionally, the lower part of the crystallization granulation zone is provided with a water inlet pipe and a chemical dosing pipe, and the pressurization ring located in the middle of the crystallization granulation zone is used to replenish the crystallization granulation zone with seed crystals.

[0017] Optionally, the separation plate is a frustum-shaped plate with a smaller top and a larger bottom. The top of the separation plate is provided with a crystal reflux port, which connects the crystallization granulation zone and the classification chamber, allowing the fine crystals rising from the classification chamber to return to the crystallization granulation zone to continue growing.

[0018] A ring of lower discharge ports is provided between the bottom of the separation plate and the inner wall of the reaction body to input the crystals that have settled in the crystallization granulation zone into the classification chamber.

[0019] Optionally, the grading chamber includes, from top to bottom, a second filter screen, a third filter screen, a disturbance device, and a sludge discharge port. Both the second and third filter screens are horizontally arranged, and their outer edges are connected to the inner side of a vertical plate. The top of the vertical plate is connected to the bottom of a separation plate, and the bottom of the vertical plate extends to the lower middle part of the grading chamber. Crystals falling from the crystallization and granulation area fall along the outer side of the vertical plate into the lower middle part of the grading chamber. The vertical plate is vertically arranged.

[0020] The bottom of the grading chamber is conical, and a sludge discharge port is provided at the bottom of the cone.

[0021] Optionally, the mesh size of the second filter screen is smaller than that of the third filter screen, enabling graded filtration of solid precipitates; the inlet of the suction tube is located below the second filter screen, allowing suction of crystals that can pass through the third filter screen but not the second filter screen. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a staged crystallization reactor for forced wastewater circulation.

[0023] Figure 2 This is a schematic diagram of the swing spoke structure;

[0024] Figure 3 This is a schematic diagram of the separator.

[0025] Figure 4 This is a schematic diagram of the booster ring structure;

[0026] Figure 5 This is a structural diagram of the separation plate and the classification chamber.

[0027] In the attached diagram, 1-reaction body, 2-outlet, 3-separator, 4-oscillating radiator, 5-crystallization and granulation zone, 6-classification chamber, 7-inlet pipe, 8-dosing pipe, 9-separation plate, 10-disturbance device, 11-suction pipe, 12-high pressure pump, 13-drain pipe, 14-pressure booster ring, 15-nozzle, 16-first filter screen, 17-second filter screen, 18-third filter screen, 19-vibrator, 20-vertical plate, 21-oscillating blade, 22-connecting shaft, 23-frame, 24-crystal reflux port, 25-lower discharge port, 26-sludge discharge port, 27-upper swing arm, 28-lower swing arm, 29-first hydraulic cylinder, 30-second hydraulic cylinder. Detailed Implementation

[0028] This embodiment provides a staged crystallization reactor with forced wastewater circulation, such as... Figures 1-5 As shown, the reaction body 1 includes, from top to bottom, an outlet 2, a separator 3, a swinging disc 4, a crystallization and granulation zone 5, and a classification chamber 6. The crystallization and granulation zone 5 is connected to an inlet pipe 7 and a dosing pipe 8 on its side, and a separation plate 9 with a smaller top and a larger bottom is provided at the bottom. The classification chamber 6 is provided with a disturbance device 10, which is used to disturb the solid particles in the classification chamber 6, so that the small solid particles float to the top and the large solid particles sink to the bottom.

[0029] The reaction body 1 is equipped with a forced circulation device, which includes a suction pipe 11, a high-pressure pump 12, a drain pipe 13 and several parallel pressurizing rings 14 connected in sequence. The suction pipe 11 is connected to the upper middle part of the classification chamber 6 and is used to suction out small part solid particles in the classification chamber 6. Several pressurizing rings 14 are connected in parallel to the drain pipe 13. The pressurizing rings 14 are located at least below the separator 3, below the swinging radiator 4 and in the crystallization granulation zone 5. Several nozzles 15 are uniformly arranged on the upper and lower surfaces of the pressurizing rings 14 for spraying out the small part solid particles extracted from the classification chamber 6.

[0030] Optionally, the separator 3 includes several layers of first filter screens 16 stacked one on top of the other. The first filter screens 16 are wavy, and the troughs of adjacent first filter screens 16 correspond to each other. That is, the trough of the upper first filter screen 16 sinks into the trough of the lower first filter screen 16, and the crest of the lower first filter screen 16 sinks into the crest of the upper first filter screen 16. This saves space and prevents excessive scale buildup on the lower surface of the first filter screens 16, because the jet impact of the pressure ring 14 below the separator 3 will act on the stacked layers of first filter screens 16.

[0031] Alternatively, the mesh size of the several layers of the first filter screen 16 decreases from bottom to top;

[0032] The external part of the reaction body 1 is provided with several vibrators 19 corresponding to the position of the separator 3. Each vibrator 19 is connected to a first filter screen 16 and is used to vibrate the first filter screen 16, thereby causing the crystals or scale on the first filter screen 16 to gather or fall off.

[0033] The first filter screens 16 of the present invention are stacked in a staggered manner, and the gaps between adjacent first filter screens 16 are small, resulting in a small space for scale to form. When there is a lot of scale or caking on the lower surface of the first filter screens 16, it will affect the water output or flow rate. The pressure ring 14 below the separator 3 can then start flushing the first filter screens 16. Moreover, the mesh size of the first filter screens 16 is smaller as they go up, making them more prone to clogging. The pressure ring 14 flushes the first filter screens 16 from bottom to top. Once the lower first filter screens 16 have been flushed, the upper first filter screens 16 will naturally be flushed until all layers of first filter screens 16 have been flushed, thus clearing the passage of the separator 3.

[0034] Optionally, the separator 3 is provided with an outlet weir above it, and an outlet 2 is provided on the outside of the outlet weir for overflowing water and outputting the reaction body 1 after crystallization separation.

[0035] Optionally, the swinging spoke 4 includes several swinging blades 21, a connecting shaft 22, a frame 23 and a swinging mechanism. The frame 23 is fixed on the inner wall of the reaction body 1. Several swinging blades 21 are parallel to each other and their two ends are rotatably connected to the inner side of the frame 23. For example, the center horizontal line of the swinging blades 21 extends and rotatably connects to the inner side of the frame 23, so that the swinging blades 21 can swing.

[0036] The connecting shaft 22 is a thin steel wire that passes through the center of each swing blade 21. The center of the swing blade 21 has a vertical through hole, which allows the thin steel wire to move more flexibly in the through hole when the swing blade 21 swings. The two ends of the thin steel wire are fixed to the inner wall of the reaction body 1 or the inner wall of the frame 23.

[0037] The swing mechanism includes an upper swing rod 27, a lower swing rod 28, a first hydraulic cylinder 29, and a second hydraulic cylinder 30. The first hydraulic cylinder 29 and the second hydraulic cylinder 30 are both located outside the reaction body 1 and are connected to the upper swing rod 27 and the lower swing rod 28 respectively through their respective hydraulic rods. The upper swing rod 27 and the lower swing rod 28 penetrate horizontally into the reaction body 1. The upper swing rod 27 is connected to the upper end of each swing blade 21, and the lower swing rod 28 is connected to the lower end of each swing blade 21. The upper swing rod 27 and the lower swing rod 28 are located on the left and right sides of the connecting shaft 22 and are close to the connecting shaft 22.

[0038] When the first hydraulic cylinder 29 pushes the upper swing rod 27 into the reaction body 1, the upper swing rod 27 causes the tops of all the swing blades 21 to move to the left. At the same time, the second hydraulic cylinder 30 pulls the lower swing rod 28 outward from the reaction body 1. The lower swing rod 28 causes the bottoms of all the swing blades 21 to move to the right. At this time, the swing blades 21 change from a vertical state to an inclined state, and can even gradually change to a horizontal state. When the second hydraulic cylinder 30 pulls the lower swing rod 28 into the reaction body 1, the lower swing rod 28 causes the bottoms of all the swing blades 21 to move to the left. At the same time, when the first hydraulic cylinder 29 pushes the upper swing rod 27 outward from the reaction body 1, the upper swing rod 27 causes the tops of all the swing blades 21 to move to the right. At this time, the swing blades 21 return from a horizontal or inclined state to a vertical state, and can even gradually change to a horizontal state in the opposite direction.

[0039] When the swinging spokes 4 swings to an inclined state, it acts as an inclined plate to separate the mud and water in the rising water. The crystals fall down the inclined plate to the crystallization and granulation zone 5, while the water rises to the separator 3 for further solid-liquid separation. When the surface of the swinging blades 21 is heavily scaled or has crystals adhering to it, the swinging blades 21 are rotated to a horizontal position, that is, the two sides of the swinging blades 21 are joined together, and several swinging blades 21 form a horizontal plate. The pressure rings 14 above and below the swinging spokes 4 flush the upper and lower surfaces of the swinging blades 21. The swinging blades 21 are rotated intermittently, so that the crystals that have fallen off the upper surface fall down along the tilted swinging blades 21.

[0040] Optionally, the booster ring 14 is in the form of a spiral coil. The upper surface of the booster ring 14 is provided with three nozzles 15, which are respectively located at the center of the upper surface and near the two side edges. Each nozzle is evenly provided with several nozzles 15. The nozzles 15 of the central nozzle are vertically upward, and the nozzles 15 of the two side nozzles are inclined to the sides, so that the spray direction of the nozzles 15 of the two side nozzles is away from the vertical direction of the central nozzle 15.

[0041] The lower surface of the booster ring 14 is provided with three nozzles 15, which are located at the center of the lower surface and near the two side edges respectively. Each nozzle 15 is evenly provided with several nozzles 15. The nozzle 15 of the center nozzle of the lower surface is vertically downward, and the nozzles 15 of the two side nozzles of the lower surface are inclined to the sides respectively, so that the spray direction of the nozzles 15 of the two side nozzles is far away from the vertical direction of the center nozzle 15.

[0042] Each nozzle 15 is evenly distributed along the spiral direction of the booster ring 14.

[0043] Further optionally, the inclination angle of the nozzles 15 on both sides of the upper and lower surfaces of the booster ring 14 is 35-55°.

[0044] The pressurizing ring 14 of this invention mixes small solid particles and water drawn from the classification chamber 6 and ejects the mixture from the nozzle 15. The design of multiple nozzles 15 on the upper and lower surfaces of the pressurizing ring 14, along with the spirally coiled rings, allows for a multi-dimensional jet of jet that impacts and washes the separator 3 and the oscillating spokes 4 from different angles. This invention breaks through the limitation of traditional jet flushing using only liquids. It extracts a suspension containing a large amount of small solid particles from the classification chamber 6, pressurizes it, and ejects it from the pressurizing ring 14, forming a solid-liquid mixed jet. This increases the impact force and provides excellent flushing effect on crystal scale or caking on the separator 3 and the oscillating spokes 4. After flushing, the solid matter falls. Due to the jet action of the pressurizing ring 14, the solid matter falling onto the pressurizing ring 14 experiences uneven force and will continue to fall into the crystallization and granulation zone 5, ensuring the cleanliness of the pressurizing ring 14.

[0045] Optionally, the lower part of the crystallization granulation zone 5 is provided with a water inlet pipe 7 and a chemical dosing pipe 8. The pressure boosting ring 14, located in the middle of the crystallization granulation zone 5, is used to replenish the crystal seed in the crystallization granulation zone 5. Wastewater and precipitant (sodium carbonate) are input into the crystallization granulation zone 5, forming a fluidized zone under the action of water flow. The small solid particles input by the pressure boosting ring 14 serve as crystal seeds, promoting crystal crystallization and growth. The crystals are mainly calcium carbonate. Large crystal particles fall into the classification chamber 6 through the separation plate 9. Some crystals move with the water flow to the oscillating spokes 4 and the separator 3 for solid-liquid separation.

[0046] Optionally, a seed tube is connected to the side of the crystallization granulation zone 5, allowing seeds to be added directly through the seed tube.

[0047] Optionally, the separation plate 9 is a frustum shape with a smaller top and a larger bottom. The top of the separation plate 9 is provided with a crystal return port 24, which connects the crystallization granulation zone 5 and the classification chamber 6, allowing the fine crystals rising from the classification chamber 6 to return to the crystallization granulation zone 5 to continue growing.

[0048] A ring of lower discharge ports 25 is provided between the bottom of the separation plate 9 and the inner wall of the reaction body 1 to input the crystals that have settled in the crystallization granulation zone 5 into the classification chamber 6.

[0049] Optionally, the grading chamber 6 includes, from top to bottom, a second filter screen 17, a third filter screen 18, a disturbance device 10, and a sludge discharge port 26. The second filter screen 17 and the third filter screen 18 are both horizontally arranged, and their outer edges are connected to the inner side of the vertical plate 20. The top of the vertical plate 20 is connected to the bottom of the separation plate 9, and the bottom of the vertical plate 20 extends to the lower middle part of the grading chamber 6. Crystals falling from the crystallization granulation zone 5 fall into the lower middle part of the grading chamber 6 along the outer side of the vertical plate 20. The vertical plate 20 is vertically arranged.

[0050] The bottom of the grading chamber 6 is conical, and a sludge discharge port 26 is provided at the bottom of the conical shape.

[0051] Optionally, the agitation device 10, corresponding to the center of the second filter screen 17 and the third filter screen 18, is selected from an aeration coil or a stirrer, and can sufficiently agitate the solid sediment in the classification chamber 6. The aeration coil is connected to an external air supply device via an air pipe. The motor of the stirrer is located below the reaction body 1.

[0052] Optionally, the mesh size of the second filter screen 17 is smaller than that of the third filter screen 18, which enables the graded filtration of solid precipitates; the inlet of the suction tube 11 is located below the second filter screen 17, and it can suction crystals that can pass through the third filter screen 18 but cannot pass through the second filter screen 17.

[0053] The vertical plate 20 and the separation plate 9 can be fixed inside the reaction body 1 in various ways. For example, the vertical plate 20 can be connected to and fixed to the inner wall of the reaction body 1 by a connecting rod, and the separation plate 9 can be supported by the vertical plate 20.

[0054] When the crystal precipitate in the crystallization granulation zone 5 falls onto the separation plate 9, due to the action of the disturbance device 10, a continuous water flow enters the crystallization granulation zone 5 from the crystal return port 24. Very few crystals descending from the crystallization granulation zone 5 fall into the classification chamber 6 from the crystal return port 24; instead, they slide down the upper surface of the separation plate 9 to the lower outlet 25, and then continue sliding down the outer side of the vertical plate 20 to the lower middle part of the classification chamber 6. The disturbance device 10 disturbs the solid crystals in the classification chamber 6, forming an upward fluid flow in the center of the classification chamber 6. The fluid carries the solid upward through the third filter screen 18 and the second filter screen 17 in sequence. After layer-by-layer interception, the fine crystals that pass through the second filter screen 17 return to the crystallization granulation zone 5 through the crystal return port 24 to continue growing or serve as seed crystals. The solid particles intercepted by the third filter screen 18 are larger than those intercepted by the second filter screen 17. The solid particles intercepted by the second filter screen 17 are larger than those that can pass through the crystal return port 24. The suction pipe 11 returns the solid crystals intercepted by the second filter screen 17 to the pressurizing ring 14. Because the crystal size in this range is suitable, it is appropriate to use it as the jet flushing separator 3 and the oscillating spokes 4. The larger solid particles settle to the bottom of the classification chamber 6 and are discharged through the sludge discharge port 26, resulting in a relatively uniform solid sediment.

[0055] This invention separates calcium carbonate crystals of different particle sizes by setting up a grading chamber 6. Combined with a separation plate 9, as described above, crystals of each particle size are utilized or rationally processed to obtain calcium carbonate crystals with relatively uniform particle size, which serve as a desulfurizing agent. Simultaneously, the crystals between the second filter screen 17 and the third filter screen 18 are rationally utilized, working in conjunction with a pressure ring to rinse the separator 3 and the oscillating spokes 4.

Claims

1. A staged crystallization reactor for forced wastewater circulation, characterized in that, The reaction body includes, from top to bottom, an outlet, a separator, a swinging disc, a crystallization and granulation zone, and a classification chamber. The classification chamber is equipped with a disturbance device to agitate the solid particles within the classification chamber. The reaction body is equipped with a forced circulation device, which includes a suction pipe, a high-pressure pump, a drain pipe and several parallel pressurizing rings connected in sequence. The suction pipe is connected to the upper middle part of the classification chamber and is used to suction out small solid particles from the classification chamber. The drain pipe is connected to several pressurizing rings in parallel. The pressurizing rings are located at least below the separator, below the swinging radii and in the crystallization granulation zone. Several nozzles are uniformly arranged on the upper and lower surfaces of the pressurizing rings for spraying out the small solid particles extracted from the classification chamber. The bottom of the crystallization granulation zone is provided with a separation plate, which is a frustum-shaped plate with a smaller top and a larger bottom. The top of the separation plate is provided with a crystal reflux port, which connects the crystallization granulation zone and the classification chamber. A ring of lower discharge ports is provided between the bottom of the separation plate and the inner wall of the reaction body to input the crystals that have settled in the crystallization granulation zone into the classification chamber; The grading chamber includes, from top to bottom, a second filter screen, a third filter screen, a disturbance device, and a sludge discharge port. The second and third filter screens are both horizontally arranged, and their outer edges are connected to the inner side of a vertical plate. The top of the vertical plate is connected to the bottom of a separation plate, and the bottom of the vertical plate extends to the lower middle part of the grading chamber. Crystals falling from the crystallization and granulation area fall into the lower middle part of the grading chamber along the outer side of the vertical plate. The bottom of the grading chamber is conical, and a sludge discharge port is provided at the bottom of the cone. The second filter screen has a smaller pore size than the third filter screen, which enables it to filter solid sediments in stages. The suction tube has its opening below the second filter screen, and it draws in crystals that can pass through the third filter screen but not the second filter screen.

2. The staged crystallization reactor for forced wastewater circulation according to claim 1, characterized in that, The separator includes several layers of first filter screens stacked one on top of the other. The outside of the reaction body is provided with several vibrators corresponding to the position of the separator. Each vibrator is connected to a first filter screen and is used to vibrate the first filter screen.

3. The staged crystallization reactor for forced wastewater circulation according to claim 2, characterized in that, The mesh size of the first filter screen decreases layer by layer from bottom to top; The first filter screen is wavy, with the troughs of the adjacent first filters corresponding to each other. The trough of the upper first filter screen sinks into the trough of the lower first filter screen, and the peak of the lower first filter screen sinks into the peak of the upper first filter screen.

4. The staged crystallization reactor for forced wastewater circulation according to claim 1, characterized in that, The oscillating spokes include several oscillating blades, a connecting shaft, a frame, and an oscillating mechanism. The frame is fixed to the inner wall of the reaction body. The several oscillating blades are parallel to each other and their two ends are rotatably connected to the inner side of the frame. The connecting shaft is a thin steel wire that passes through the center of each oscillating blade. The swing mechanism includes an upper swing arm, a lower swing arm, a first hydraulic cylinder, and a second hydraulic cylinder. Both the first and second hydraulic cylinders are located outside the reaction body and are connected to the upper and lower swing arms respectively through their respective hydraulic rods. The upper and lower swing arms penetrate horizontally into the reaction body. The upper swing arm is connected to the upper end of each swing blade, and the lower swing arm is connected to the lower end of each swing blade.

5. The staged crystallization reactor for forced wastewater circulation according to claim 1, characterized in that, The booster ring is in the form of a spiral coil. Three nozzles are provided on the upper surface of the booster ring, located at the center and near the two side edges of the upper surface. Several nozzles are evenly arranged in each nozzle. The nozzles of the central nozzle are vertically upward, while the nozzles of the two side nozzles are inclined to the sides. The lower surface of the booster ring is provided with three nozzles, located at the center and near the two side edges of the lower surface. Each nozzle is evenly provided with several nozzles. The nozzle of the central nozzle on the lower surface is vertically downward, while the nozzles of the two side nozzles on the lower surface are inclined to the sides. This ensures that the spray direction of the nozzles on the upper and lower surfaces is away from the vertical direction of the central nozzle. Each nozzle is evenly distributed along the spiral direction of the booster ring.

6. The staged crystallization reactor for forced wastewater circulation according to claim 1, characterized in that, The lower part of the crystallization granulation zone is equipped with a water inlet pipe and a chemical dosing pipe. The pressurization ring located in the middle of the crystallization granulation zone is used to replenish the crystal seed in the crystallization granulation zone.

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