Phosphorus crystal recovery device

Abstract

The utility model relates to the technical field of sewage treatment, in particular to a phosphorus crystal recovery device. The device comprises an outer shell, a middle shell, an inner shell, a plug flow stirring assembly, a folded plate vortex assembly, a modular vortex assembly and an inclined plate assembly, and a circulating flow channel and a second water flow ascending channel which are formed by combining a first water flow ascending channel and a water flow descending channel are formed. Stirring blades and a folded plate vortex assembly in the plug-flow stirring assembly are arranged in a first water flow ascending channel, a modular vortex assembly is arranged in a water flow descending channel, an inclined plate assembly is arranged in a second water flow ascending channel, and wastewater is uniformly mixed to form tiny crystals when passing through the first water flow ascending channel; and large-particle crystal grains are obtained under the action of micro vortexes in the water flow circulating channel, enter the second water flow ascending channel, fall into the crystal gathering area under the dual action of gravity and the inclined plate assembly and then are discharged, the overall structure of the device is simple, efficient phosphorus recycling can be achieved, and practicability is high.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a phosphorus crystal recovery device. Background Technology

[0002] Recovering phosphorus from wastewater and converting it into phosphate fertilizer reduces phosphorus emissions from wastewater and protects the aquatic environment.

[0003] Phosphorus in the liquid phase is currently mainly recovered and utilized through crystallization. Orthophosphate (PO4) in the liquid phase... 3－ Phosphorus crystallizes and precipitates in the form of phosphate minerals, primarily in the forms of struvite (magnesium ammonium phosphate, MAP) and hydroxyapatite (HAP). The resulting products have low heavy metal content and can be directly applied in agriculture, thus realizing the resource utilization of phosphorus. Struvite crystallization is currently the most widely researched and applied phosphorus recovery technology because it can simultaneously recover phosphorus and ammonia nitrogen from the liquid phase.

[0004] The reactor is the core device in the phosphorus crystallization recovery process. The type and design of the reactor directly affect the purity of the product. At present, stirred crystallization reactors are mostly used to synthesize magnesium ammonium phosphate. However, they have disadvantages such as low purity of synthesized products and more impurities. In addition, the crystal particles formed are small in size, which adversely affects the efficiency of phosphorus recovery.

[0005] In summary, there is an urgent need for a device with a simplified structure that facilitates phosphorus recovery to solve the problems existing in the current technology. Utility Model Content

[0006] The purpose of this invention is to provide a phosphorus crystallization recovery device with a simplified structure that facilitates phosphorus recovery. The device includes an outer shell, a middle shell, an inner shell, an inlet pipe, a outlet pipe, a discharge port, a flow-pushing and stirring assembly, a baffle vortex assembly, a modular vortex assembly, and an inclined plate assembly. The outer shell, middle shell, and inner shell are nested together to form a circulating flow channel and a second water flow upward channel, which are formed by a combination of a first water flow upward channel and a water flow downward channel. The stirring blades and baffle vortex assembly in the flow-pushing and stirring assembly are arranged from top to bottom in the first water flow upward channel, combined with the modular vortex assembly in the water flow downward channel, constituting a mechanical stirring and mixing process for crystallization and water recovery. The vortex crystallization composite system, due to its unique structure, achieves hydraulic classification during operation, ensuring thorough mixing of materials and fluidizing crystal particles. It achieves self-induced crystallization without the need for external seed crystals, resulting in larger crystal particle sizes compared to traditional stirred crystallization. The first upward and downward water flow channels form a circulating flow channel that automatically sorts crystal particles. Larger particles are automatically separated from the circulating water flow and discharged into the crystal aggregation zone under gravity, while smaller particles continue to crystallize in the circulating water channel. The crystal particles collected in the aggregation zone are larger and purer than those in traditional stirred crystallization, achieving highly efficient phosphorus recovery. An inclined plate assembly is installed in the second upward water flow channel to perform secondary separation of fine crystalline particles entrained in the water flow, further improving the recovery efficiency of phosphorus crystal particles.

[0007] The specific technical solution is as follows:

[0008] A phosphorus crystallization recovery device includes an outer shell, a middle shell, an inner shell, an inlet pipe, an outlet pipe, a discharge port, a flow-pushing and stirring assembly, a baffle vortex assembly, a modular vortex assembly, and an inclined plate assembly.

[0009] The upper end of the outer shell is provided with a removable cover plate for sealing, and the lower end of the outer shell is a closed end. The outer shell includes a first columnar cylinder and a first conical cylinder arranged in series from top to bottom. The upper part of the first columnar cylinder is provided with a water collection tank.

[0010] The middle shell is located inside the first columnar cylinder, and it includes a second columnar cylinder arranged in series from top to bottom and a second conical cylinder that is wider at the top and narrower at the bottom and has an opening at the lower end;

[0011] The inner shell has openings at both the upper and lower ends. The inner shell includes a third columnar cylinder, a third conical cylinder, and a fourth columnar cylinder arranged in series from top to bottom. The upper parts of the third columnar cylinder and the third conical cylinder are located inside the middle shell, and the lower end of the fourth columnar cylinder is located outside the middle shell and inside the first conical cylinder.

[0012] The inner cavities of the third cylindrical body, the third conical body, and the fourth cylindrical body are connected to form a first water flow upward channel; a water flow downward channel is formed between the outer wall of the third cylindrical body, the outer wall of the third conical body, and the inner wall of the middle shell; the outer wall of the middle shell, the inner wall of the outer shell, and the water collection tank enclose a second water flow upward channel; a crystal aggregation region is formed in the lower part of the first conical body; the flow-pushing and stirring assembly and the baffle vortex assembly are arranged from top to bottom in the first water flow upward channel; the modular vortex assembly is arranged in the water flow downward channel; and the inclined plate assembly is arranged in the second water flow upward channel.

[0013] The inlet pipe penetrates the side wall of the first cylindrical body and the side wall of the second cylindrical body and is inserted into the upper part of the first water flow rising channel, and the outlet end of the inlet pipe is lower than the water collection tank; the drain pipe is connected to the water collection tank.

[0014] Preferably, the stirring assembly includes a stirring power source, a stirring shaft, and stirring blades. The stirring power source is mounted on a detachable cover plate. The connecting end of the stirring shaft is connected to the output end of the stirring power source. The free end of the stirring shaft extends through the detachable cover plate into the third cylindrical body. The stirring blades are mounted on the free end of the stirring shaft. The outlet end of the liquid inlet pipe is located 20-50 cm above the stirring blades. The design of the stirring power source, stirring shaft, and stirring blades provides sufficient upward force for the water flow in the first upward channel, facilitating the smooth entry of the liquid into the downward channel. It also facilitates the contact and mixing of orthophosphate in the inlet water and crystal-forming ions (magnesium ions, ammonium ions) in the reagent under mechanical stirring conditions to form tiny magnesium ammonium phosphate crystals (nuclei).

[0015] Preferably, the folded plate vortex assembly is located directly below the flow-pushing and stirring assembly, and the folded plate vortex assembly includes a first folded plate and a second folded plate arranged side by side. The first folded plate includes multiple connecting plates connected in sequence, and the included angle α between two adjacent connecting plates is 80°-100°; the first folded plate and the second folded plate are mirror images of each other. The unique design of the folded plate vortex assembly can promote the generation of vortices and enhance the formation and growth of grains.

[0016] Preferably, the top of the folded vortex assembly is 0.4–0.8 m from the lower edge of the flow-pushing and stirring assembly, and its lower end is flush with the lower end of the fifth receiving cavity; the first and second folded plates are arranged alternately. Preferably, the upper end of the modular vortex assembly is 0.5 m below the liquid surface in the first receiving cavity, and its lower end is 0.4 m–0.8 m from the lower end of the first receiving cavity; the modular vortex assembly is a fan-ring cylindrical cube, and its horizontal projection is a fan-ring shape. Preferably, the modular vortex assembly includes multiple vortex units stacked or spaced apart, and each vortex unit is a hollow columnar body enclosed by a first vertical plate, a second vertical plate, an upper arc-shaped outer frame, an upper arc-shaped inner frame, a lower arc-shaped outer frame, and a lower arc-shaped inner frame.

[0017] Preferably, the vortex unit is equipped with vortex plates, the cross-section of which is at least one of triangular, semi-circular, and rectangular. Preferably, the inclined plate assembly includes multiple sedimentation inclined plates arranged side by side, the sedimentation inclined plates being set at an angle to the inner wall of the first columnar cylinder; and the inclined plate assembly is located in the lower middle part of the first columnar cylinder. Preferably, the size of the opening of the second conical cylinder is 0.3-0.6 times the size of the second columnar cylinder; the first columnar cylinder, the first conical cylinder, the second columnar cylinder, the second conical cylinder, the third columnar cylinder, the third conical cylinder, and the fourth columnar cylinder are arranged along the same central axis. Preferably, it also includes a micro-nano aeration disc, the micro-nano aeration disc being located above the crystal aggregation area and directly below the lower opening of the fourth columnar cylinder; the micro-nano aeration disc is connected to an external air source through an air pipe; the discharge port is provided with a compressed air pipe connected to an external compressed air source, which is used to clear the discharge port with compressed air when the discharge port is blocked.

[0018] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the figures. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0020] Figure 1 This is a schematic diagram of the phosphorus crystallization recovery device in the selected embodiment (the black arrows in the diagram represent the direction of water flow);

[0021] Figure 2 for Figure 1 Top view of the vortex assembly of the middle folding plate installed in the inner housing;

[0022] Figure 3 for Figure 2 MM cross-section diagram;

[0023] Figure 4 for Figure 1 Schematic diagram of the structure of a single vortex unit in a modular vortex assembly;

[0024] Figure 5 for Figure 4 Top view after installing multiple vortex vanes;

[0025] Figure 6 for Figure 5 NN cross-sectional view.

[0026] The components include: 1. Outer shell: 1.1 First cylindrical body, 1.2 First conical body, 1.3 First receiving cavity, 1.4 Second receiving cavity, 1.5 Removable cover plate; 2. Middle shell: 2.1 Second cylindrical body, 2.2 Second conical body, 2.3 Third receiving cavity, 2.4 Fourth receiving cavity; 3. Inner shell: 3.1 Third cylindrical body, 3.2 Fifth receiving cavity; 4. Water collection tank; 5. Liquid inlet pipe; 6. Liquid outlet pipe; 7. Discharge port; 8. Flow-pushing and stirring assembly: 8.1 Stirring power source; 8.2 8.3. Stirring shaft; 9. Baffle vortex assembly; 9.1. First folding plate; 9.2. Second folding plate; a. Connecting plate; 10. Modular vortex assembly; 10.1. First vertical plate; 10.2. Second vertical plate; 10.3. Upper arc-shaped outer frame; 10.4. Upper arc-shaped inner frame; 10.5. Lower arc-shaped outer frame; 10.6. Lower arc-shaped inner frame; b. Semi-circular shell vortex plate; c. Isosceles right-angled triangular vortex plate; 11. Inclined plate assembly; 12. Micro-nano aeration disc; 13. Air pipe; 14. Compressed air pipe;

[0027] A. First water flow upward channel, B. Water flow downward channel, C. Second water flow upward channel, D. Crystal aggregation region. Detailed Implementation

[0028] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0029] Example:

[0030] See Figure 1 A phosphorus crystallization recovery device includes an outer shell 1, a middle shell 2, an inner shell 3, an inlet pipe 5, a outlet pipe 6, a discharge port 7, a flow-pushing and stirring assembly 8, a baffle plate vortex assembly 9, a modular vortex assembly 10, and an inclined plate assembly 11. Details are as follows:

[0031] The upper end of the outer shell 1 is sealed with a removable cover plate 1.5, and the lower end of the outer shell 1 is a closed end. The outer shell 1 includes a first cylindrical body 1.1 and a first conical body 1.2 (shown as a frustum-shaped structure in the figure) arranged in series from top to bottom. The first cylindrical body 1.1 has a first receiving cavity 1.3, and the first conical body 1.2 has a second receiving cavity 1.4 communicating with the first receiving cavity 1.3. The discharge port 7 communicates with the second receiving cavity 1.4. A water collection tank 4 is provided at the upper part of the first receiving cavity 1.3. Preferably, in this embodiment, the discharge port 7 is located at the bottom of the side wall of the second receiving cavity 1.4, and a crystal aggregation region D is formed at the lower part of the second receiving cavity 1.4. The discharge port is used to discharge the crystals in the crystal aggregation region D. The water collection tank has an annular structure.

[0032] The middle shell 2 is located inside the first cylindrical body 1.1, and it includes a second cylindrical body 2.1 arranged in series from top to bottom and a second conical body 2.2 that is wider at the top and narrower at the bottom and has an opening at the lower end. The second cylindrical body 2.1 is provided with a third receiving cavity 2.3, and the second conical body 2.2 is provided with a fourth receiving cavity 2.4 that communicates with the third receiving cavity 2.3. The upper end of the second conical body 2.2 is located inside the first receiving cavity 1.3 and its lower end is located inside the second receiving cavity 1.4.

[0033] The inner shell 3 has openings at both its upper and lower ends. The inner shell 3 includes a third cylindrical body 3.1, a third conical cylindrical body 3.3, and a fourth cylindrical body 3.4, arranged in series from top to bottom. The upper parts of the third cylindrical body 3.1 and the third conical cylindrical body 3.3 are located inside the middle shell 2, while the lower end of the fourth cylindrical body 3.4 is located outside the middle shell 2 and inside the first conical cylindrical body 1.2. The inner cavities of the third cylindrical body 3.1, the third conical cylindrical body 3.3, and the fourth cylindrical body 3.4 form a fifth receiving cavity 3.2. Preferably, in this embodiment, the size of the opening of the second conical cylindrical body 2.2 is 0.3-0.6 times the size of the fifth receiving cavity 3.2.

[0034] The fifth receiving cavity 3.2 forms a first water flow upward channel A; a water flow downward channel B is formed between the inner wall of the second cylindrical body 2.1 (i.e., the inner wall of the third receiving cavity 2.3) and the outer wall of the third cylindrical body 3.1 (i.e., the inner wall of the fifth receiving cavity); the inner walls of the first receiving cavity 1.3, the second receiving cavity 1.4, the third receiving cavity 2.3, the fourth receiving cavity 2.4, and the water collection tank 4 enclose a second water flow upward channel C. In this embodiment: the lower end of the second conical cylinder 2.2 is provided with an opening to facilitate fluid flowing from the fourth receiving cavity into the second receiving cavity and into the second water flow upward channel C; the upper end of the fifth receiving cavity 3.2 is provided with an opening to facilitate fluid entering the corresponding water flow downward channel B area in the third receiving cavity from the first water flow upward channel A in the fifth receiving cavity; the lower end of the fifth receiving cavity 3.2 is provided with an opening to facilitate fluid entering the first water flow upward channel A in the fifth receiving cavity from the corresponding water flow downward channel B area in the fourth receiving cavity, thereby causing liquid circulation.

[0035] The stirring blades of the jet-flushing assembly 8 and the baffle vortex assembly 9 are arranged from top to bottom in the first water flow rising channel A; the modular vortex assembly 10 is arranged in the water flow descending channel B; and the inclined plate assembly 11 is arranged in the second water flow rising channel C. The detailed structures of the jet-flushing assembly 8, the baffle vortex assembly 9, the modular vortex assembly 10, and the inclined plate assembly 11 are as follows:

[0036] The propulsion and stirring assembly 8 includes a stirring power source 8.1, a stirring shaft 8.2, and stirring blades 8.3. The stirring power source 8.1 is mounted on a detachable cover plate 1.5. The connecting end of the stirring shaft 8.2 is connected to the output end of the stirring power source 8.1. The free end of the stirring shaft 8.2 extends through the detachable cover plate 1.5 into the third cylindrical body 3.1. The stirring blades 8.3 are mounted on the free end of the stirring shaft 8.2. The outlet end of the liquid inlet pipe 5 is located 20-50 cm above the stirring blades 8.3. In this embodiment, the propulsion and stirring device 8 lifts the liquid and suspended particles located in the lower section of the first water flow rising channel A in the fifth receiving cavity 3.2 to the upper section of the first water flow rising channel A, and provides a driving force for the circulation of water.

[0037] The folding vortex assembly 9 is located directly below the jet-stirring assembly 8, and the folding vortex assembly 9 includes a first folding plate 9.1 and a second folding plate 9.2 arranged side by side. The first folding plate 9.1 includes multiple connecting plates a connected in sequence, and the included angle α between two adjacent connecting plates a is 80°-100°. The first folding plate 9.1 and the second folding plate 9.2 are mirror images of each other. In this preferred embodiment, see [reference needed]. Figure 2 and Figure 3The top of the folded plate vortex assembly 9 is 0.4 to 0.8 m away from the lower edge of the push-flow stirring assembly 8, and its lower end is flush with the lower end of the fifth receiving cavity 3.2. The folded plate vortex assembly 9 includes two first folded plates 9.1 and two second folded plates 9.2, which are arranged alternately. The length L1 of the connecting plate a is 20% to 30% of the diameter of the fifth receiving cavity 3.2. The lengths of the corresponding connecting plates in the same first or second folded plate are the same. The crests and troughs of adjacent first and second folded plates are horizontally aligned. The horizontal distance L2 between the first and second folded plates is equal and is 10% to 15% of the diameter of the fifth receiving cavity 3.2.

[0038] The upper end of the modular vortex assembly 10 is located 0.5m below the liquid surface in the first receiving cavity 1.3, and its lower end is 0.4m to 0.8m from the lower end of the first receiving cavity 1.3. The modular vortex assembly 10 is a fan-ring cylindrical cube, and its horizontal projection is a fan-ring shape. Preferably, in this embodiment, the modular vortex assembly 10 includes multiple vortex units stacked or spaced apart. Each vortex unit is a hollow columnar body enclosed by a first vertical plate 10.1, a second vertical plate 10.2, an upper arc-shaped outer frame 10.3, an upper arc-shaped inner frame 10.4, a lower arc-shaped outer frame 10.5, and a lower arc-shaped inner frame 10.6. See [reference needed]. Figure 4 Further preferably, the first vertical plate 10.1, the second vertical plate 10.2, the upper arc-shaped outer frame 10.3, the upper arc-shaped inner frame 10.4, the lower arc-shaped outer frame 10.5, and the lower arc-shaped inner frame 10.6 are all made of metal or engineering plastic materials, and can withstand the weight of the frame itself and the vortex plates installed inside.

[0039] In a further preferred embodiment, the vortex unit is equipped with vortex vanes, the cross-section of which is at least one of triangular, semi-circular, and rectangular. Figure 5 and Figure 6The vortex unit is equipped with multiple vortex plates inside. The vortex plates include at least one of a semi-circular shell vortex plate b and an isosceles right-angled triangular vortex plate c. The figure shows that the semi-circular shell vortex plate and the isosceles right-angled triangular vortex plate are alternately arranged. The projection of a single semi-circular shell vortex plate in the horizontal direction is an arc shape, and its cross-sectional shape is semi-circular with a diameter of 30-40mm. The horizontal spacing between each semi-circular shell vortex plate in the same layer is equal, and is 1-1.3 times its diameter. The length of each semi-circular shell vortex plate in the same layer is determined by the radius of its own horizontal projection arc and the arc radius corresponding to the horizontal projection of the vortex unit frame. The projection of a single isosceles right-angled triangular shell vortex plate in the horizontal direction is an arc shape, and its cross-sectional shape is an isosceles right-angled triangle. The height of the triangle is the same as the radius of the semi-circular shell vortex plate. The horizontal spacing between each isosceles right-angled triangular shell vortex plate in the same layer is equal, and is 1-1.3 times its height. Adjacent layers of vortex plates are staggered, and the projections of adjacent layers of vortex plates on the horizontal plane do not overlap. The layer spacing is 1-1.5 times the diameter of the vortex plate.

[0040] The inclined plate assembly 11 includes multiple sedimentation inclined plates arranged in parallel, the sedimentation inclined plates being arranged at an angle to the inner wall of the first receiving cavity; and the inclined plate assembly 11 is located in the lower middle part of the first receiving cavity.

[0041] The inlet pipe 5 penetrates the side walls of the first cylindrical body 1.1 and the second cylindrical body 2.1, and is inserted into the upper part of the first water flow rising channel A. The outlet end of the inlet pipe 5 is lower than the position of the water collection tank 4. Preferably, in this embodiment, the inlet pipe 5 includes a horizontal pipe section, an arc-shaped transition pipe section, and a vertical pipe section. The horizontal pipe section penetrates the side walls of the first cylindrical body 1.1 and the second cylindrical body 2.1. The outlet end of the vertical pipe section is lower than the position of the water collection tank 4. Preferably, the outlet end of the vertical pipe section is located 0.3 to 0.5 meters above the upper surface of the stirring blade. The drain pipe 6 is connected to the water collection tank 4. In a further preferred embodiment, the first cylindrical body 1.1, the first conical body 1.2, the second cylindrical body 2.1, the second conical body 2.2, and the third cylindrical body 3.1 are arranged along the same central axis.

[0042] In addition, this embodiment also includes a micro-nano aeration disc 12, which is a prior art product, located above the crystal aggregation region D and directly below the lower opening of the fourth columnar cylinder 3.4; the micro-nano aeration disc 12 is connected to an external air source through an air pipe 13. The opening at the bottom of the first water flow rising channel is located in the crystal aggregation region at the bottom of the outer shell, and a micro-nano aeration disc is provided below it, so that small crystal particles in the crystal aggregation region can act as seed crystals and enter the water flow circulation channel with the water flow, providing ready-made nucleation sites for the solution, reducing the critical supersaturation required for the system to form new crystal nuclei, thereby reducing the probability of spontaneous nucleation (forming a large number of tiny crystals), and suppressing the formation of irregular dendritic or needle-like crystals, promoting the formation of more dense and uniform prismatic or plate-like large crystal particles. In this embodiment, the discharge port 7 is provided with a compressed air pipe 14 connected to an external compressed air source, which is used to clear the discharge port with compressed air when it is blocked.

[0043] The specific application of the technical solution of this utility model is as follows:

[0044] Wastewater containing orthophosphate is mixed with reagents (magnesium salts, ammonium salts, and alkalis when struvite crystallization is used) and then enters the first water flow upward channel A through the inlet pipe 5 (located above the stirring blades 8.3). The stirring power source 8.1 is started, driving the stirring shaft 8.2 and the stirring blades 8.3 on it to rotate, generating an upward thrust to stir and mix the liquid and suspended particles in the first water flow upward channel A, so that the liquid mixture circulates in the lower section of the first water flow upward channel A, the upper section of the first water flow upward channel A, and the water flow downward channel B.

[0045] Under the mechanical stirring conditions of the propagating agitator 8, the orthophosphate in the influent and the crystal-forming ions (magnesium ions and ammonium ions) in the reagent come into contact and mix to form tiny magnesium ammonium phosphate crystals (crystal nuclei). These tiny crystals circulate with the water flow in the lower section of the first upward water flow channel A, the upper section of the first upward water flow channel A, and the downward water flow channel B. When passing through the baffle vortex assembly 9 and the modular vortex assembly 10, the crystal-forming ions in the wastewater further come into contact and mix under the action of a large number of micro-vortices generated by the baffle vortex assembly 9 and the modular vortex assembly 10, causing the tiny crystal particles to fluidize. Under the action of the micro-vortices, the tiny crystals and the crystal nuclei and crystal-forming ions collide and contact fully, resulting in secondary nucleation. Self-induced crystallization is achieved without the need for external seed crystals. The particle size of the crystals gradually increases. When the particle size and mass increase to a certain extent, under the action of gravity, the large crystal particles gradually detach automatically from the circulating water flow and flow out from the lower opening of the fourth receiving chamber, falling into the crystal aggregation zone D. After crystallization, the water flow out from the lower opening of the fourth receiving chamber and enters the second water flow rising channel C. The fine crystal particles carried in the water flow undergo further solid-liquid separation under the action of gravity and the inclined plate assembly 11. After sedimentation, the crystal particles slide down to the crystal aggregation zone D under the action of gravity. The supernatant after sedimentation flows upward through the second water flow rising channel C and collects in the water collection tank 4, and is discharged from the phosphorus crystallization recovery device through the drain pipe 6. The struvite crystals accumulated in the crystal aggregation zone D are periodically discharged through the discharge port 7.

[0046] The technical solution of this embodiment has the following beneficial effects:

[0047] 1. The phosphorus crystallization recovery device of this embodiment adopts an outer shell, a middle shell, and an inner shell arranged from the outside to the inside to form a first water flow upward channel, a water flow downward channel, and a second water flow upward channel. In the first water flow upward channel, a push-flow stirring component and a baffle vortex component are arranged from top to bottom. In the water flow downward channel, a modular vortex component is arranged. The mechanical stirring component and the vortex component installed in the circulation channel constitute a mechanical stirring mixing crystallization + hydraulic vortex crystallization composite system. Due to its special structure, hydraulic classification is realized in the water flow downward channel during operation, so that the solution is fully mixed with materials and the crystal particles are fluidized. Self-induced crystallization is achieved without the addition of external crystal seeds, and the particle size of the crystal particles is larger than that of traditional stirring crystallization.

[0048] 2. In this embodiment, the water circulation channel formed by the combination of the middle shell and the inner shell in the phosphorus crystallization recovery device can automatically sort crystal particles. Larger particles will automatically detach from the circulating water and enter the crystal aggregation zone under the action of gravity, while smaller particles will continue to crystallize in the water circulation channel. When the size and mass reach a certain level, they will automatically detach from the circulating water and enter the crystal aggregation zone under the action of gravity. The crystal particles collected in the crystal aggregation zone are larger in size and have higher purity than those collected by traditional stirring crystallization.

[0049] 3. In this embodiment, the opening at the bottom of the first water flow rising channel is located in the crystal aggregation area at the bottom of the outer shell and a micro-nano aeration disc is provided below it. This allows small crystal particles in the crystal aggregation area to act as seed crystals and enter the water flow circulation channel with the water flow, providing ready-made nucleation sites for the solution. This reduces the critical supersaturation required for the system to form new crystal nuclei, thereby reducing the probability of spontaneous nucleation (forming a large number of tiny crystals) and suppressing the formation of irregular dendritic or needle-like crystals, promoting the formation of more dense and uniform prismatic or plate-like large crystal particles.

[0050] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A phosphorus crystallization recovery apparatus characterized by comprising: The device comprises an outer shell (1), a middle shell (2), an inner shell (3), a liquid inlet pipe (5), a liquid outlet pipe (6), a discharge port (7), a push-flow stirring assembly (8), a folded-plate vortex assembly (9), a modular vortex assembly (10), and an inclined plate assembly (11). The upper end of the outer shell (1) is provided with a detachable cover plate (1.5) for sealing, and the lower end of the outer shell (1) is a closed end. The outer shell (1) comprises a first cylindrical body (1.1) and a first conical body (1.2) arranged in series from top to bottom. The upper part of the first cylindrical body (1.1) is provided with a water collecting tank (4). The middle shell (2) is located in the first cylindrical body (1.1) and comprises a second cylindrical body (2.1) and a second conical body (2.2) arranged in series from top to bottom. The second conical body (2.2) is wide at the top and narrow at the bottom, and the lower end is provided with an opening. The upper end and the lower end of the inner shell (3) are both provided with openings. The inner shell (3) comprises a third cylindrical body (3.1), a third conical body (3.3), and a fourth cylindrical body (3.4) arranged in series from top to bottom. The upper part of the third cylindrical body (3.1) and the third conical body (3.3) is located in the middle shell (2), and the lower end of the fourth cylindrical body (3.4) is located outside the middle shell (2) and in the first conical body (1.2). The inner cavities of the third cylindrical body (3.1), the third conical body (3.3), and the fourth cylindrical body (3.4) are connected to form a first water flow upward channel (A). The outer wall of the third cylindrical body (3.1), the outer wall of the third conical body (3.3), and the inner wall of the middle shell (2) form a water flow downward channel (B). The outer wall of the middle shell (2), the inner wall of the outer shell (1), and the water collecting tank (4) enclose a second water flow upward channel (C). The lower part of the first conical body (1.2) forms a crystal aggregation area (D). The stirring blades in the push-flow stirring assembly (8) and the folded-plate vortex assembly (9) are arranged in the first water flow upward channel (A) from top to bottom. The modular vortex assembly (10) is arranged in the water flow downward channel (B). The inclined plate assembly (11) is arranged in the second water flow upward channel (C). The liquid inlet pipe (5) penetrates the side wall of the first cylindrical body (1.1) and the side wall of the second cylindrical body (2.1) and is inserted into the upper part of the first water flow upward channel (A). The outlet end of the liquid inlet pipe (5) is lower than the position of the water collecting tank (4). The liquid outlet pipe (6) communicates with the water collecting tank (4).

2. The phosphorus crystallization recovery apparatus according to claim 1, characterized by The push-flow stirring assembly (8) comprises a stirring power source (8.1), a stirring shaft (8.2) and stirring blades (8.3), the stirring power source (8.1) is arranged on the detachable cover plate (1.5), the connecting end of the stirring shaft (8.2) is connected with the output end of the stirring power source (8.1), the free end of the stirring shaft (8.2) penetrates through the detachable cover plate (1.5) and is arranged in the third cylindrical barrel (3.1), and the stirring blades (8.3) are arranged on the free end of the stirring shaft (8.2); the water outlet end of the liquid inlet pipe (5) is located 20-50 cm above the stirring blades (8.3).

3. The phosphorus crystallization recovery apparatus according to claim 1, characterized by The folded-plate vortex assembly (9) is located directly below the push-flow stirring assembly (8), and the folded-plate vortex assembly (9) comprises first folded plates (9.1) and second folded plates (9.2) arranged side by side, the first folded plates (9.1) comprise a plurality of connecting plates (a) connected in sequence, and the included angle α between adjacent two connecting plates (a) is 80°-100°.

4. The phosphorus crystallization recovery apparatus according to claim 3, characterized by The top end of the folded-plate vortex assembly (9) is 0.4-0.8 m away from the lower edge of the push-flow stirring assembly (8); the first folded plates (9.1) and the second folded plates (9.2) are arranged alternately; and the first folded plates (9.1) and the second folded plates (9.2) are mirror image structures.

5. The phosphorus crystallization recovery apparatus according to claim 1, characterized by The upper end of the modular vortex assembly (10) is located 0.5 m below the liquid level in the first cylindrical barrel (1.1), and the lower end is 0.4-0.8 m away from the lower end of the first cylindrical barrel (1.1); the shape of the modular vortex assembly (10) is a fan-ring cylindrical cube, and the horizontal projection is a fan-ring shape.

6. The phosphorus crystallization recovery apparatus according to claim 5, characterized by The modular vortex assembly (10) comprises a plurality of vortex monomers arranged in layers or at intervals, and the vortex monomer is a hollow cylindrical body enclosed by a first vertical plate (10.1), a second vertical plate (10.2), an upper arc-shaped outer frame (10.3), an upper arc-shaped inner frame (10.4), a lower arc-shaped outer frame (10.5) and a lower arc-shaped inner frame (10.6).

7. The phosphorus crystallization recovery apparatus according to claim 6, characterized by The vortex monomer is provided with a vortex sheet, and the cross section of the vortex sheet is at least one of a triangle, a semicircle and a rectangle.

8. The phosphorus crystallization recovery apparatus according to claim 1, characterized by The inclined plate assembly (11) comprises a plurality of sedimentation inclined plates arranged side by side, the sedimentation inclined plates are arranged at an angle with the inner wall of the first cylindrical barrel (1.1), and the inclined plate assembly (11) is located in the middle and lower part of the first cylindrical barrel (1.1).

9. The phosphorus crystallization recovery apparatus according to claim 1, characterized by The size of the opening of the second conical barrel (2.2) is 0.3-0.6 times the size of the second cylindrical barrel (2.1); the first cylindrical barrel (1.1), the first conical barrel (1.2), the second cylindrical barrel (2.1), the second conical barrel (2.2), the third cylindrical barrel (3.1), the third conical barrel (3.3) and the fourth cylindrical barrel (3.4) are arranged on the same central axis.

10. The phosphorus crystallization recovery apparatus according to any one of claims 1 to 9, characterized by Also included are micro-nano aeration discs (12) located at the upper part of the crystal aggregation zone (D) and directly below the lower end opening of the fourth cylindrical body (3.4); the micro-nano aeration discs (12) are in communication with the external air source through an air pipe (13); A compressed air pipe (14) in communication with the external compressed air source is arranged at the discharge port (7) for unblocking the discharge port when it is blocked.

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