A device for separating and recycling by-product salt from phosphate production wastewater

Abstract

The present application relates to wastewater treatment technical field, disclose a kind of phosphate production wastewater by-product salt separation and reuse device, including the communication of adjusting pool, neutralization reaction pool, sedimentation tank, filter, buffer tank and wastewater separation and reuse equipment in sequence;Wastewater separation and reuse equipment includes wastewater crystallization cylinder, rotationally arranged in its inner rotating cylinder and the force frame and filter plate being arranged along the circumference of inner rotating cylinder, cooling jacket is arranged outside wastewater crystallization cylinder;Force frame is driven filter plate to agitate wastewater when rotating, intercepts by-product salt crystal and scrapes cylinder wall, simultaneously promotes material removal groove to move along guide curve groove, so that material removal groove and filter plate relative displacement to clean, collect and discharge crystal.The present application can complete cooling crystallization, solid-liquid separation, cooling surface cleaning and by-product salt discharge in continuous operation state, reduce shutdown cleaning, improve processing efficiency and operating stability.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a device for separating and reusing by-product salts from phosphate production wastewater. Background Technology

[0002] Wastewater generated during phosphate production typically contains a certain concentration of phosphate, metal ions, suspended solids, and soluble by-products, characterized by high salt content and complex composition. This type of wastewater generally undergoes pretreatment such as adjustment, neutralization, sedimentation, and filtration to remove suspended impurities and some precipitable substances. Then, cooling and crystallization are used to make the soluble by-products in the wastewater reach a supersaturated state and precipitate crystals. Subsequently, solid-liquid separation is carried out by filtration, sedimentation, or centrifugation, so that the treated water can enter the subsequent reuse stage. At the same time, the separated by-products are collected and treated.

[0003] In existing technologies, the cooling crystallization and solid-liquid separation of wastewater are usually carried out in steps using different equipment. The crystallized slurry needs to be discharged and transported to subsequent separation equipment. The transfer between equipment not only increases the processing flow and operation steps, but also easily leads to crystal deposition and material retention, affecting the continuity of wastewater treatment. At the same time, by-product salt crystals tend to adhere to the heat exchange surface of the crystallization equipment during precipitation and may gradually accumulate on the filter components, resulting in a decrease in heat exchange efficiency and solid-liquid separation efficiency. Long-term operation often requires shutdown and drainage for cleaning and maintenance, thereby extending the treatment cycle and increasing equipment operation and maintenance costs. Summary of the Invention

[0004] The technical problem to be solved by this invention is that the existing wastewater by-product salt treatment process for phosphate production has problems such as poor connection between crystallization and solid-liquid separation, easy adhesion and accumulation of crystals, and frequent shutdowns for cleaning. To address this, we propose a wastewater by-product salt separation and reuse device for phosphate production.

[0005] To achieve the above objectives, this application adopts the following technical solution: a phosphate production wastewater by-product salt separation and reuse device, comprising an equalization tank, a neutralization reaction tank, a sedimentation tank, a filter, a buffer tank, and wastewater separation and reuse equipment connected in sequence; The wastewater separation and reuse equipment includes an equipment frame, a wastewater crystallization cylinder installed on the equipment frame, an inner rotating cylinder rotatably disposed in the middle of the wastewater crystallization cylinder, and a drive mechanism for driving the inner rotating cylinder to rotate. An annular processing chamber is formed between the inner rotating cylinder and the wastewater crystallization cylinder, and a cooling jacket is provided on the wastewater crystallization cylinder. The inner rotating cylinder is provided with multiple load-bearing frames that penetrate the inner rotating cylinder in the circumferential direction. Filter plates located in the annular treatment chamber are installed on the load-bearing frames. The end of the load-bearing frame away from the inner rotating cylinder corresponds to the inner wall of the wastewater crystallization cylinder. The upper part of the wastewater crystallizer is provided with a material transfer mechanism. The material transfer mechanism includes an outer shell disposed on the outside of the wastewater crystallizer, a sliding plate movably disposed on the inner wall of the outer shell and capable of moving around the axis of the wastewater crystallizer, and a material transfer groove movably disposed on the sliding plate along the radial direction of the wastewater crystallizer. The inner wall of the outer shell is provided with a guide groove, and the material transfer groove is provided with a guide shaft that movably cooperates with the guide groove. When the load-bearing frame rotates with the inner rotating cylinder to the transfer trough, it can push the transfer trough to move, so that the transfer trough moves radially outward along the wastewater crystallization cylinder during the movement and has a relative displacement with the filter plate to collect the secondary salt crystals on the filter plate. As the transfer trough moves around the wastewater crystallization cylinder, its end away from the load-bearing frame gradually faces downward.

[0006] Preferably, the lower part of the annular treatment chamber is used to contain the wastewater to be treated.

[0007] Preferably, the drive mechanism includes a gear ring mounted on the outer side of one end of the inner rotating cylinder, a motor mounted on the equipment frame, and a gear mounted on the output end of the motor, wherein the gear meshes with the gear ring.

[0008] Preferably, a plurality of the load-bearing frames are arranged at intervals along the circumference of the inner rotating cylinder, with one end of the load-bearing frame extending to the inner side of the inner rotating cylinder and the other end extending toward the inner wall of the wastewater crystallization cylinder. The filter plate is used to agitate the wastewater in the annular treatment chamber when it rotates with the inner rotating cylinder, and to intercept the precipitated secondary salt crystals and move them to the location of the transfer tank. The end of the load-bearing frame away from the inner rotating cylinder is used to scrape the inner wall of the wastewater crystallization cylinder.

[0009] Preferably, the transfer groove is provided with an arc-shaped rod, one end of which extends to the outside of the outer shell, and a first elastic element is sleeved on the arc-shaped rod; when the transfer groove is pushed and moved by the load-bearing frame, it will drive the arc-shaped rod to move and cause the first elastic element to undergo elastic deformation.

[0010] Preferably, the end sidewall of the transfer trough is rotatably provided with multiple rollers, and the transfer trough rolls with the sidewall of the support frame through the rollers.

[0011] Preferably, a flexible scraper is provided on the side of the transfer trough near the filter plate. The flexible scraper contacts the surface of the filter plate and is used to scrape the secondary salt crystals on the surface of the filter plate into the transfer trough when the transfer trough and the filter plate move relative to each other.

[0012] Preferably, the outer shell is provided with a guide plate, which is located below the discharge end of the transfer trough and is inclined downward along the discharge direction of the secondary salt crystals.

[0013] Preferably, it also includes an air blowing mechanism, which includes an air blowing pipe mounted on the equipment frame. One end of the air blowing pipe extends to the inside of the inner rotating cylinder and is rotatably connected to the inner rotating cylinder. The end of the air blowing pipe located inside the inner rotating cylinder is a closed end, and the closed end is rotatably provided with a rotating sleeve. Multiple load-bearing frames are connected to the rotating sleeve at one end on the inner side of the inner rotating cylinder. The load-bearing frame is provided with an air passage that communicates with the rotating sleeve. The air blowing pipe is provided with an air port. When the load-bearing frame rotates to the discharge position, the air passage in the corresponding load-bearing frame communicates with the air port. The end of the load-bearing frame away from the inner rotating cylinder is provided with an air-gathering cavity that communicates with the air passage, and the air-gathering cavity is provided with an air-blowing hole facing the material transfer trough.

[0014] Preferably, when the support frame rotates to the discharge position and the transfer trough moves to a position corresponding to the end of the support frame away from the inner rotating cylinder, the air blowing hole corresponds to the bottom wall of the inner cavity of the transfer trough, so that the airflow is blown into the interior of the transfer trough through the air blowing hole.

[0015] Preferably, the load-bearing frame is provided with a sealing assembly, which includes a sealing strip that is movably and sealingly disposed in the gas collection cavity. The sealing strip is used to block the communication position between the air passage and the gas collection cavity. When the transfer trough moves to the discharge position, it can drive the sealing strip to release the blockage of the air passage. After the transfer trough leaves the discharge position, the sealing strip re-blocks the air passage.

[0016] Preferably, the end of the load-bearing frame away from the inner rotating cylinder is provided with a groove corresponding to the air collection chamber, a wedge-shaped force-bearing block is movably arranged in the groove, a second elastic element is provided between the wedge-shaped force-bearing block and the inner wall of the groove, and the sealing strip is connected to the wedge-shaped force-bearing block; A portion of the wedge-shaped force-bearing block protrudes from the side wall of the load-bearing frame under the action of the second elastic element, and the protruding portion of the wedge-shaped force-bearing block is provided with an inclined surface for cooperating with the transfer groove.

[0017] The technical effects and advantages of this invention are as follows: This invention utilizes an inner rotating cylinder within a wastewater crystallization cylinder to create an annular treatment chamber for the wastewater. Multiple support frames and filter plates are arranged circumferentially within the inner rotating cylinder. As the inner rotating cylinder rotates, the filter plates continuously agitate the wastewater within the annular treatment chamber, resulting in a more uniform temperature distribution and promoting the crystallization of byproducts. Simultaneously, the filter plates trap and remove precipitated byproduct crystals from the wastewater, achieving a continuous connection between cooling crystallization and solid-liquid separation. Furthermore, the support frames, during rotation, scrape the inner wall of the wastewater crystallization cylinder, reducing the amount of byproduct crystals precipitated during cooling. The system removes the adhesion and accumulation on the filter plate surface. When the support frame moves to the transfer trough, it pushes the transfer trough along a predetermined trajectory, causing relative displacement between the transfer trough and the filter plate. The flexible scraper scrapes the secondary salt crystals on the filter plate surface into the transfer trough. After the transfer trough moves to the discharge position, its discharge end tilts downward, allowing the secondary salt crystals to be automatically discharged into the secondary salt collection box. Thus, without stopping the machine to drain water or manually disassembling the filter plate, the wastewater agitation, crystal interception, cooling surface cleaning, filter plate cleaning, and secondary salt discharge can be completed sequentially, improving the continuity and treatment efficiency of wastewater secondary salt separation.

[0018] This invention further includes an air blowing mechanism consisting of an air blowing pipe, a rotating sleeve, an air passage, an air collection chamber, and an air blowing hole. A sealing assembly, formed by a wedge-shaped force-bearing block, a sealing strip, and a second elastic element, opens and closes according to the position of the transfer trough. When the transfer trough reaches the discharge position, the wedge-shaped force-bearing block is pressed, causing the sealing strip to release the blockage of the air passage, allowing airflow to be directed through the air blowing hole towards the inner wall of the transfer trough to remove any attached or retained secondary salt crystals. After the transfer trough leaves, the sealing strip re-closes the air passage under the action of the second elastic element, reducing the possibility of wastewater entering the air passage. This structure improves the thoroughness of secondary salt discharge, reduces blockage inside the transfer trough and residual crystals, and ensures the long-term stability of the device. Attached Figure Description

[0019] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts: Figure 1 This is a schematic diagram of the entire wastewater treatment process of the present invention; Figure 2 This is a schematic diagram of the wastewater separation and reuse equipment of the present invention; Figure 3 This is a schematic diagram of the wastewater separation and reuse equipment of the present invention from another perspective; Figure 4 This is a schematic diagram of the structure of the wastewater crystallization cylinder and the outer shell of the present invention in a disassembled state; Figure 5 This is a schematic diagram of the overall structure of the outer shell and the transfer tank of the present invention; Figure 6This is a schematic diagram of the structure of the outer shell and the transfer tank of the present invention in a disassembled state; Figure 7 This is a schematic diagram showing the initial positional relationship between the transfer tank and the wastewater crystallization cylinder of the present invention; Figure 8 This is a schematic diagram of the material transfer tank of the present invention; Figure 9 This is a structural schematic diagram of the wastewater crystallizing cylinder, inner rotating cylinder, and load-bearing frame of the present invention in a disassembled state. Figure 10 This is a schematic diagram of the load-bearing frame of the present invention; Figure 11 This is a schematic diagram of the disassembled structure of the load-bearing frame in a partial cross-sectional state according to the present invention.

[0020] Legend: 1. Equipment frame; 2. Wastewater crystallization cylinder; 3. Inner rotating cylinder; 4. Outer shell; 5. Air blowing pipe; 6. Gear ring; 7. Motor; 8. Gear; 9. Filter plate; 10. Guide plate; 11. Arc rod; 12. First elastic element; 13. Transfer trough; 14. Slide plate; 15. Guide curved groove; 16. Guide shaft; 17. Load-bearing frame; 18. Roller; 19. Flexible scraper; 20. Wedge-shaped force-bearing block; 21. Air blowing hole; 22. Air passage; 23. Sealing strip; 24. Air collection chamber; 25. Second elastic element; 26. Groove; 27. Rotating sleeve; 28. Air port. Detailed Implementation

[0021] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0022] Reference Figures 1-11 As shown, this invention provides a wastewater by-product salt separation and reuse device for phosphate production, mainly comprising an equalization tank, a neutralization reaction tank, a sedimentation tank, a filter, a buffer tank, and wastewater separation and reuse equipment connected in sequence. Phosphate production wastewater first enters the equalization tank for flow and quality adjustment, then enters the neutralization reaction tank for pH adjustment and to precipitate some impurities. The wastewater after neutralization enters the sedimentation tank for solid-liquid sedimentation separation. The effluent from the sedimentation tank passes through a filter to further remove residual suspended solids before entering the buffer tank. The buffer tank temporarily stores the pretreated wastewater and stabilizes the subsequent influent flow rate. The wastewater in the buffer tank is then transported to the wastewater separation and reuse equipment for cooling, crystallization, and solid-liquid separation. The separated by-product salt is discharged into a by-product salt collection tank, and the treated water is discharged into a reuse water tank for reuse in the production process.

[0023] It should be noted that this embodiment is mainly used for crystallizing and separating potassium dihydrogen phosphate from phosphate production wastewater. The wastewater entering the wastewater separation and reuse equipment contains potassium dihydrogen phosphate that has reached or is close to saturation. By cooling the wastewater to lower the temperature, the potassium dihydrogen phosphate becomes supersaturated and crystals precipitate. For the mother liquor mainly containing dipotassium hydrogen phosphate, phosphoric acid can be added to the neutralization reaction tank before entering the wastewater separation and reuse equipment for acidification and adjustment, so that the dipotassium hydrogen phosphate in the mother liquor is converted into potassium dihydrogen phosphate. The concentration is adjusted as necessary according to the concentration of the mother liquor so that the treated mother liquor meets the feeding conditions required for the cooling and crystallization of potassium dihydrogen phosphate. After sedimentation, filtration and buffering treatment, it is then transported to the wastewater separation and reuse equipment to complete the crystallization and solid-liquid separation of potassium dihydrogen phosphate crystals.

[0024] The aforementioned equalization tank, neutralization reaction tank, sedimentation tank, filter, buffer tank, by-product salt collection tank, and recycled water tank can all be conventional equipment in the field of water treatment. Corresponding dosing, conveying, and control components can be configured according to the water quality, treatment volume, and reuse requirements of the phosphate production wastewater. Their specific structures and operating methods will not be elaborated here. This embodiment focuses on describing the structure of the wastewater separation and reuse equipment and its cooling crystallization, solid-liquid separation, and by-product salt discharge processes.

[0025] The wastewater separation and reuse equipment includes a frame 1 and a wastewater crystallization cylinder 2 installed on the frame 1. An inner rotating cylinder 3 is coaxially rotatable inside the wastewater crystallization cylinder 2. The outer wall of the inner rotating cylinder 3 and the inner wall of the wastewater crystallization cylinder 2 form an annular treatment cavity for containing wastewater. The upper part of the wastewater crystallization cylinder 2 is provided with a wastewater inlet connected to a buffer tank, and the bottom is provided with a drain outlet connected to a reuse water tank. A cooling jacket is provided on the outer side of the lower end of the wastewater crystallization cylinder 2. The cooling jacket is connected to an external cooling medium circulation device so that the cooling medium circulates within the cooling jacket and exchanges heat with the wastewater in the annular treatment cavity through the cylinder wall of the wastewater crystallization cylinder 2. During wastewater treatment, the wastewater level is maintained in the lower region of the annular treatment cavity, so that the cooling jacket corresponds to the main containment area of ​​the wastewater, thereby cooling the wastewater and promoting the precipitation of soluble by-product salts to form by-product salt crystals.

[0026] To continuously collect byproduct salt crystals and separate solids and liquids without emptying the wastewater, multiple filter plates 9 are spaced circumferentially around the outer periphery of the inner rotating cylinder 3, located inside the wastewater crystallization cylinder 2. When the inner rotating cylinder 3 rotates, it drives multiple filter plates 9 to sequentially enter and exit the wastewater in the lower part of the annular treatment chamber. The movement of the filter plates 9 in the wastewater agitates the wastewater, making the wastewater temperature and byproduct salt concentration distribution more uniform and reducing the possibility of byproduct salt crystals concentrating and depositing locally. When the filter plates 9 leave the wastewater, the liquid can pass through the filter plates 9, while byproduct salt crystals with a particle size larger than the filter pores are trapped on the filter plates 9 and move upward with the filter plates 9, thereby achieving dynamic separation of byproduct salt crystals from the treated water. The filter pore size of the filter plates 9 can be selected according to the particle size of the target byproduct salt crystals.

[0027] To drive the inner rotating cylinder 3 to rotate, a gear ring 6 is fixedly installed on the outer side of one end of the inner rotating cylinder 3. A motor 7 is installed on the equipment frame 1. A gear 8 that meshes with the gear ring 6 is fixedly installed at the output end of the motor 7. When the motor 7 is working, it drives the inner rotating cylinder 3 to rotate around its own axis through the gear 8 and the gear ring 6, so that multiple filter plates 9 sequentially complete the cycle of immersing in wastewater, intercepting secondary salt crystals, lifting and draining water, and removing secondary salt crystals. The motor 7 can be a drive motor that can adjust the speed, so as to adjust the running speed of the filter plates 9 according to the generation rate of secondary salt crystals and the wastewater treatment volume.

[0028] To remove and discharge the secondary salt crystals trapped on the filter plate 9, a material transfer mechanism is provided at the upper part of the wastewater crystallization cylinder 2. The material transfer mechanism includes an outer shell 4 covering the outside of the wastewater crystallization cylinder 2, and a sliding plate 14 that can move circumferentially along the wastewater crystallization cylinder 2 is provided on the upper inner wall of the outer shell 4. An arc-shaped guide rail coaxial with the wastewater crystallization cylinder 2 can be provided on the side wall of the outer shell 4, and the sliding plate 14 slides in conjunction with the arc-shaped guide rail. A material transfer groove 13 is movably provided on the sliding plate 14 along the radial direction of the wastewater crystallization cylinder 2. Both ends of the material transfer groove 13 are open structures. The end closer to the wastewater crystallizer 2 is the feed end, and the end farther away from the wastewater crystallizer 2 is the discharge end. The inner wall of the outer shell 4 is provided with a guide groove 15 corresponding to the slide plate 14, and the side wall of the transfer trough 13 is rotatably provided with a guide shaft 16 extending into the guide groove 15. When the slide plate 14 drives the transfer trough 13 to move circumferentially along the wastewater crystallizer 2, the guide shaft 16 moves along the guide groove 15 and guides the transfer trough 13 to move radially relative to the slide plate 14, so that the transfer trough 13 gradually approaches or moves away from the wastewater crystallizer 2 during the movement.

[0029] A load-bearing frame 17, corresponding to the filter plates 9, is installed circumferentially through the inner rotating cylinder 3. Each filter plate 9 is installed on its corresponding load-bearing frame 17. One end of the load-bearing frame 17 extends to the inner side of the inner rotating cylinder 3 and is connected to the air blowing mechanism, while the other end extends toward the inner wall of the wastewater crystallization cylinder 2. The outer edge of the load-bearing frame 17 is close to or has a clearance fit with the inner wall of the wastewater crystallization cylinder 2, so that the load-bearing frame 17 can scrape the secondary salt crystals attached near the cooling surface when it rotates with the inner rotating cylinder 3. The top of the wastewater crystallization cylinder 2 is provided with an opening for the feed end of the transfer trough 13 to enter and exit. In the initial state, the feed of the transfer trough 13 is... The end extends into the wastewater crystallization cylinder 2 through the opening and is located on the movement path of the filter plate 9; when the support frame 17 drives the filter plate 9 to rotate to the transfer trough 13, the support frame 17 contacts the transfer trough 13 and pushes the transfer trough 13 and the slide plate 14 to move circumferentially. At the same time, the lower end of the transfer trough 13 moves relative to the surface of the filter plate 9 to scrape the secondary salt crystals on the filter plate 9 into the transfer trough 13; under the cooperation of the guide shaft 16 and the guide groove 15, the transfer trough 13 gradually moves to the outside of the wastewater crystallization cylinder 2 until the discharge end of the transfer trough 13 forms a downward discharge state, and the secondary salt crystals are discharged from the discharge end.

[0030] To ensure the stable entry of discharged secondary salt crystals into the secondary salt collection box, a guide plate 10 is provided on the outer shell 4 below the discharge path of the transfer trough 13. The guide plate 10 is used to receive the secondary salt crystals discharged from the transfer trough 13 and guide them to the secondary salt collection box. To achieve automatic reset of the transfer trough 13, one end of the transfer trough 13 is connected to an arc-shaped rod 11. A first elastic element 12 is sleeved on the arc-shaped rod 11. One end of the arc-shaped rod 11 extends to the outside of the outer shell 4. The first elastic element 12 is located between the transfer trough 13 and the outer shell 4 or at... On the outside of the outer shell 4; when the support frame 17 pushes the transfer groove 13 to move, the arc rod 11 moves with the transfer groove 13 and causes the first elastic element 12 to undergo elastic deformation; when the support frame 17 passes over the transfer groove 13 and separates from it, the first elastic element 12 releases elastic potential energy, driving the transfer groove 13 and the slide plate 14 back to the initial position to wait for the next support frame 17 and filter plate 9 to arrive. The first elastic element 12 is preferably a compression spring; and in order to avoid rigid impact during reset, a buffer structure such as a buffer pad corresponding to the transfer groove 13 can be provided at the end of the outer shell 4.

[0031] When it is necessary to suspend the removal of secondary salt crystals or to inspect the wastewater crystallization cylinder 2, a locking structure can be installed to limit the position of the transfer trough 13. The locking structure can be a locking bolt or pin installed on the outer shell 4. When the transfer trough 13 moves to a position away from the inner rotating cylinder 3, the locking structure fixes the transfer trough 13 or the slide plate 14, so that the feed end of the transfer trough 13 exits the movement path of the load-bearing frame 17 and the filter plate 9, avoiding interference with the rotation of the inner rotating cylinder 3. After the locking is released, the first elastic element 12 can restore the transfer trough 13 to the secondary salt crystal collection position. The locking structure is an optional conventional limiting component that can be set according to the equipment operation and maintenance requirements.

[0032] To reduce the frictional resistance when the transfer trough 13 contacts the support frame 17, multiple rollers 18 are rotatably provided on the end sidewall of the transfer trough 13. The transfer trough 13 rolls with the sidewall of the support frame 17 through the rollers 18, so that the support frame 17 can smoothly push the transfer trough 13 to move. A flexible scraper 19 is provided on the lower edge of the transfer trough 13. The flexible scraper 19 abuts against the surface of the filter plate 9 when the transfer trough 13 moves relative to the filter plate 9, and is used to scrape the secondary salt crystals on the filter plate 9 into the transfer trough 13. The flexible scraper 19 can be made of acid and alkali resistant silicone rubber, polyurethane elastic material or other materials with corrosion resistance and elastic recovery ability, so as to reduce wear on the filter plate 9 while adapting to the surface deformation and assembly error of the filter plate 9.

[0033] With the above structure, the filter plate 9, driven by the inner rotating cylinder 3, has the functions of stirring, crystal interception and crystal lifting. The load-bearing frame 17 can scrape the inner wall of the wastewater crystallization cylinder 2 while supporting the filter plate 9. When the filter plate 9 moves to the transfer position, the load-bearing frame 17 pushes the transfer trough 13 to move, and the flexible scraper 19 scrapes off the secondary salt crystals on the filter plate 9. The transfer trough 13 then moves outward under the guidance of the guide trough 15 and discharges the secondary salt crystals. Thus, cooling crystallization, solid-liquid separation, filter plate cleaning and secondary salt discharge can be continuously completed while retaining the treated water in the annular treatment chamber, reducing the treatment interruption caused by shutdown drainage and manual cleaning.

[0034] To reduce the adhesion and accumulation of secondary salt crystals on the inner wall of the transfer tank 13, the wastewater separation and reuse equipment is also equipped with an air blowing mechanism. The air blowing mechanism includes an air blowing pipe 5 installed on the equipment frame 1. One end of the air blowing pipe 5 is connected to an external air source, and the other end extends to the inner side of the inner rotating cylinder 3 and forms a closed end. The external air source is preferably compressed air that has been treated to remove oil and water, or inert gases such as nitrogen can be used according to the process requirements of the wastewater medium. The air blowing pipe 5 and the inner rotating cylinder 3 are rotatably fitted together, so that the air blowing pipe 5 remains relatively fixed while the inner rotating cylinder 3 can rotate around the air blowing pipe 5. A rotating sleeve 27 is rotatably sleeved on the outer side of the closed end of the air blowing pipe 5, and multiple load-bearing frames 17 are located at... One end of the inner side of the inner rotating cylinder 3 is connected to the rotating sleeve 27; each load-bearing frame 17 is provided with an air passage 22 communicating with the rotating sleeve 27, and the air blowing pipe 5 is provided with an air port 28 adapted to the air passage 22; the air port 28 is located at the circumferential position corresponding to the discharge position of the secondary salt crystal. When one of the load-bearing frames 17 rotates to the discharge position, the air passage 22 in the load-bearing frame 17 is connected to the air port 28, so that air is supplied only to the load-bearing frame 17 in the discharge position; the end of the load-bearing frame 17 away from the inner rotating cylinder 3 is provided with an air collecting chamber 24 communicating with the air passage 22, and the air collecting chamber 24 is provided with an air blowing hole 21 facing the inner cavity of the transfer trough 13.

[0035] To prevent wastewater or secondary salt crystals from entering the air passage 22 when the support frame 17 is immersed in wastewater, a sealing assembly is provided on the support frame 17; the sealing assembly includes a sealing strip 23 that is movably and sealingly disposed in the air collection cavity 24 and used to close the air passage 22, and a groove 26 corresponding to the air collection cavity 24 is provided on the side wall of the support frame 17 away from the inner rotating cylinder 3, a wedge-shaped force-bearing block 20 is movably disposed in the groove 26, and a second elastic element 25 is provided between the wedge-shaped force-bearing block 20 and the inner wall of the groove 26, and the wedge-shaped force-bearing block 20 is connected to the sealing strip 23; the second elastic element 25 is preferably a compression spring; Under the elastic force of the elastic element 25, the inclined part of the wedge-shaped force block 20 protrudes from the side wall of the support frame 17, while the sealing strip 23 is in the state of closing the air passage 22. When the lower end of the transfer groove 13 moves to the outer end of the support frame 17, the transfer groove 13 squeezes the inclined part of the wedge-shaped force block 20, causing the wedge-shaped force block 20 to retract into the groove 26 and drive the sealing strip 23 to move, thereby releasing the sealing strip 23 from the air passage 22. After the transfer groove 13 separates from the support frame 17, the second elastic element 25 pushes the wedge-shaped force block 20 to reset and causes the sealing strip 23 to re-close the air passage 22.

[0036] It should be noted that the air blowing operation is carried out when the support frame 17 pushes the transfer trough 13 to the discharge position and the two have not yet separated. At this time, the air passage 22 in the support frame 17 at the discharge position is connected to the air port 28 on the air blowing pipe 5. The transfer trough 13 squeezes the wedge-shaped force block 20 to release the sealing strip 23 from the air passage 22. The gas delivered by the external air source passes through the air blowing pipe 5, the air port 28, the air passage 22 and the air collection chamber 24 in sequence, and is sprayed from the air blowing hole 21 to the bottom wall of the inner cavity of the transfer trough 13, blowing the secondary salt crystals attached to the inner wall of the transfer trough 13 toward the discharge end. After the air blowing is completed, the inner rotating cylinder 3 continues to rotate, the support frame 17 separates from the transfer trough 13, the transfer trough 13 resets under the action of the first elastic element 12, and the sealing strip 23 re-closes the air passage 22 under the action of the second elastic element 25, thus preparing for the next secondary salt crystal removal operation.

[0037] Working principle: During operation, phosphate production wastewater sequentially passes through an equalization tank, neutralization reaction tank, sedimentation tank, and filter to complete water quality adjustment, neutralization sedimentation, and removal of suspended solids. The pretreated wastewater enters a buffer tank for temporary storage and is then transported from the buffer tank to the annular treatment chamber of the wastewater crystallization cylinder 2. The cooling medium circulates within the cooling jacket and exchanges heat with the wastewater, lowering its temperature. The soluble byproduct salts in the wastewater gradually reach supersaturation and form byproduct salt crystals. The motor 7 drives the inner rotating cylinder 3 to rotate via gear 8 and gear ring 6. Multiple filter plates 9 are immersed in the wastewater along with the inner rotating cylinder 3, agitating the wastewater. When the filter plates 9 leave the wastewater, they trap the byproduct salt crystals and allow the liquid to fall back into the annular treatment chamber. The load-bearing frame 17 moves along with the filter plates 9... During the upward movement, the inner wall of the wastewater crystallization cylinder 2 is scraped. When the support frame 17 and the filter plate 9 reach the transfer trough 13, the support frame 17 pushes the transfer trough 13 to move circumferentially and radially. The flexible scraper 19 scrapes the secondary salt crystals on the filter plate 9 into the transfer trough 13. Under the guidance of the transfer trough 13 and the blowing action of the air blowing mechanism, the secondary salt crystals enter the secondary salt collection box through the guide plate 10. The transfer trough 13 and the sealing assembly are then reset under the action of the first elastic element 12 and the second elastic element 25, respectively. The inner rotating cylinder 3 continues to rotate and repeats the above process. After the secondary salt crystals are continuously separated, the treated water in the annular treatment chamber is discharged into the recycled water tank through the drain outlet at the bottom of the wastewater crystallization cylinder 2 for reuse in the production process.

[0038] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A device for separating and reusing by-product salts from phosphate production wastewater, characterized in that, It includes a regulating tank, a neutralization reaction tank, a sedimentation tank, a filter, a buffer tank, and a wastewater separation and reuse equipment connected in sequence; The wastewater separation and reuse equipment includes an equipment frame, a wastewater crystallization cylinder installed on the equipment frame, an inner rotating cylinder rotatably disposed in the middle of the wastewater crystallization cylinder, and a drive mechanism for driving the inner rotating cylinder to rotate. An annular processing chamber is formed between the inner rotating cylinder and the wastewater crystallization cylinder, and a cooling jacket is provided on the wastewater crystallization cylinder. The inner rotating cylinder is provided with multiple load-bearing frames that penetrate the inner rotating cylinder in the circumferential direction. Filter plates located in the annular treatment chamber are installed on the load-bearing frames. The end of the load-bearing frame away from the inner rotating cylinder corresponds to the inner wall of the wastewater crystallization cylinder. The upper part of the wastewater crystallizer is provided with a material transfer mechanism. The material transfer mechanism includes an outer shell disposed on the outside of the wastewater crystallizer, a sliding plate movably disposed on the inner wall of the outer shell and capable of moving around the axis of the wastewater crystallizer, and a material transfer groove movably disposed on the sliding plate along the radial direction of the wastewater crystallizer. The inner wall of the outer shell is provided with a guide groove, and the material transfer groove is provided with a guide shaft that movably cooperates with the guide groove. When the load-bearing frame rotates with the inner rotating cylinder to the transfer trough, it can push the transfer trough to move, so that the transfer trough moves radially outward along the wastewater crystallization cylinder during the movement and has a relative displacement with the filter plate to collect the secondary salt crystals on the filter plate. As the transfer trough moves around the wastewater crystallization cylinder, its end away from the load-bearing frame gradually faces downward.

2. The phosphate production wastewater by-product salt separation and reuse device according to claim 1, characterized in that, The lower part of the annular treatment chamber is used to contain the wastewater to be treated.

3. The phosphate production wastewater by-product salt separation and reuse device according to claim 1, characterized in that, The drive mechanism includes a gear ring mounted on the outer side of one end of the inner rotating cylinder, a motor mounted on the equipment frame, and a gear mounted on the output end of the motor, wherein the gear meshes with the gear ring.

4. The phosphate production wastewater by-product salt separation and reuse device according to claim 1, characterized in that, Multiple load-bearing frames are spaced apart circumferentially along the inner rotating cylinder, with one end of each load-bearing frame extending to the inner side of the inner rotating cylinder and the other end extending toward the inner wall of the wastewater crystallization cylinder. The filter plate is used to agitate the wastewater in the annular treatment chamber when it rotates with the inner rotating cylinder, and to intercept the precipitated secondary salt crystals and move them to the location of the transfer tank. The end of the load-bearing frame away from the inner rotating cylinder is used to scrape the inner wall of the wastewater crystallization cylinder.

5. The phosphate production wastewater by-product salt separation and reuse device according to claim 1, characterized in that, An arc-shaped rod is provided on the transfer groove, one end of which extends to the outside of the outer shell, and a first elastic element is sleeved on the arc-shaped rod; when the transfer groove is pushed and moved by the load-bearing frame, it will drive the arc-shaped rod to move and cause the first elastic element to undergo elastic deformation.

6. The phosphate production wastewater by-product salt separation and reuse device according to claim 1, characterized in that, The end sidewall of the transfer trough is rotatably equipped with multiple rollers, and the transfer trough rolls with the sidewall of the load-bearing frame through the rollers.

7. The phosphate production wastewater by-product salt separation and reuse device according to claim 1, characterized in that, A flexible scraper is provided on the side of the transfer trough near the filter plate. The flexible scraper contacts the surface of the filter plate and is used to scrape the secondary salt crystals on the surface of the filter plate into the transfer trough when the transfer trough and the filter plate move relative to each other.

8. The phosphate production wastewater by-product salt separation and reuse device according to claim 1, characterized in that, The outer shell is provided with a guide plate, which is located below the discharge end of the transfer trough and is inclined downward along the discharge direction of the secondary salt crystals.

9. The phosphate production wastewater by-product salt separation and reuse device according to claim 4, characterized in that, It also includes an air blowing mechanism, which includes an air blowing pipe mounted on the equipment frame. One end of the air blowing pipe extends to the inside of the inner rotating cylinder and is rotatably connected to the inner rotating cylinder. The end of the air blowing pipe located inside the inner rotating cylinder is a closed end, and the closed end is rotatably provided with a rotating sleeve. Multiple load-bearing frames are connected to the rotating sleeve at one end on the inner side of the inner rotating cylinder. The load-bearing frame is provided with an air passage that communicates with the rotating sleeve. The air blowing pipe is provided with an air port. When the load-bearing frame rotates to the discharge position, the air passage in the corresponding load-bearing frame communicates with the air port. The end of the load-bearing frame away from the inner rotating cylinder is provided with an air-gathering cavity that communicates with the air passage, and the air-gathering cavity is provided with an air-blowing hole facing the material transfer trough.

10. The phosphate production wastewater by-product salt separation and reuse device according to claim 9, characterized in that, When the load-bearing frame rotates to the discharge position and the transfer trough moves to a position corresponding to the end of the load-bearing frame away from the inner rotating cylinder, the air blowing hole corresponds to the bottom wall of the inner cavity of the transfer trough, so that the airflow is blown into the interior of the transfer trough through the air blowing hole.

11. The phosphate production wastewater by-product salt separation and reuse device according to claim 9, characterized in that, The load-bearing frame is provided with a sealing assembly, which includes a sealing strip that is movably and sealingly disposed in the air-gathering cavity. The sealing strip is used to block the connection between the air passage and the air-gathering cavity. When the material transfer chute moves to the discharge position, it can drive the sealing strip to release the blockage of the air passage. After the material transfer chute leaves the discharge position, the sealing strip re-blocks the air passage.

12. The phosphate production wastewater by-product salt separation and reuse device according to claim 11, characterized in that, The end of the load-bearing frame away from the inner rotating cylinder is provided with a groove corresponding to the air collection chamber. A wedge-shaped force-bearing block is movably arranged in the groove. A second elastic element is provided between the wedge-shaped force-bearing block and the inner wall of the groove. The sealing strip is connected to the wedge-shaped force-bearing block. A portion of the wedge-shaped force-bearing block protrudes from the side wall of the load-bearing frame under the action of the second elastic element, and the protruding portion of the wedge-shaped force-bearing block is provided with an inclined surface for cooperating with the transfer groove.

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