Concentration and crystallization equipment for ammonium phosphate product production

Abstract

The utility model discloses concentration and crystallization equipment for ammonium phosphate product production, which comprises a main steam inlet pipeline, a main steam outlet pipeline, a solution inlet pipeline, an evaporator, a thickener and a control cabinet, the evaporator is arranged on the left side of the thickener, and the main steam inlet pipeline is arranged above the left side of the evaporator. The main steam outlet pipeline is arranged below the left side of the evaporator, the solution inlet pipeline is arranged on the front side of the evaporator, and the control cabinet is arranged on the outer side of the evaporator and is in telecommunication connection with the evaporator and the thickener. The flash evaporation device has the functions that the solution is continuously treated through the graded flash evaporation device, the evaporation efficiency of the evaporated solution is improved, meanwhile, heat in steam in the evaporator is recycled, and the heat utilization efficiency of the device is improved; crystals attached to the stirring rod are vibrated off through vibration, so that the stirring rod can be automatically cleaned, and the cleaning is convenient; and crystals are filtered, dried and recycled, so that the processing efficiency is improved, and the cost of arranging a plurality of treatment devices is saved.

Description

Technical Field

[0001] This utility model belongs to the field of ammonium phosphate production technology, and in particular relates to a concentration and crystallization device for the production of ammonium phosphate products. Background Technology

[0002] Ammonium phosphate is an inorganic compound with the chemical formula (NH4)3PO4. It is the ammonium salt of phosphate, a white crystalline powder that is readily soluble in water, slightly soluble in dilute ammonia, and insoluble in liquid ammonia, acetone, ethanol, and ether. It is mainly used as a budding agent for sugarcane growth, a fire retardant for wood, a water softener for water treatment, a biological culture medium, and an analytical chemical reagent.

[0003] The industrial production process of ammonium phosphate generally involves reaction, concentration, evaporation, crystallization, filtration, and drying. The concentration and crystallization process of ammonium phosphate usually involves steps such as solution concentration, supersaturation formation, and crystal precipitation. The specific methods vary depending on the type of ammonium phosphate (such as monoammonium phosphate, MAP, and diammonium phosphate, DAP) and the production scale.

[0004] Existing technologies, such as the neutralization and concentration reaction apparatus disclosed in Chinese Patent (CN213726472U) for the production of monoammonium phosphate, include a neutralization and concentration reactor. The reactor has an upper lid and a lower bottom. The reactor has a sealed interior chamber with a jacket between the chamber and the reactor. In this invention, the material requiring neutralization and concentration in monoammonium phosphate production is added to the reactor chamber. A stirring motor is started, driving the stirring paddle shaft to rotate, which in turn drives the stirring paddle to agitate the material inside the reactor chamber. This ensures more uniform neutralization. During neutralization, the flow rates of cooling water and steam are adjusted according to the temperature to control the neutralization reaction temperature at the optimal level. After neutralization, the cooling water inlet valve and outlet valve are closed, while the volatile steam inlet valve, steam outlet valve, and steam inlet valve are opened. Once only steam is discharged from the steam outlet valve, it is closed or partially closed.

[0005] The existing technology has the following drawbacks: First, the device uses negative pressure to lower the boiling point of the solution to evaporate the solvent. During the evaporation process, the evaporated steam carries away some heat, causing the solution temperature to drop. The solution needs to absorb heat again from the heating steam, and the solution continues to boil, increasing energy consumption and making it difficult to maintain the efficient evaporation effect of the solvent. Second, the concentrated solution enters the thickener for crystallization. The crystals precipitated at the bottom outlet of the thickener need to be filtered and dried in other devices to obtain the finished product. This requires two additional processes and equipment for separation and drying, increasing production costs. Third, the thickener is equipped with a stirring rod. During the process of stirring the concentrated liquid to accelerate crystallization and sedimentation, some crystals will accumulate on the surface of the stirring rod. These crystals continuously adhere to the stirring rod and are difficult to clean after long-term accumulation.

[0006] Therefore, this utility model provides a concentration and crystallization device for the production of ammonium phosphate products. Utility Model Content

[0007] To address the aforementioned technical problems, this utility model discloses a concentration and crystallization device for the production of ammonium phosphate products. It continuously processes the solution through a staged flash evaporation device, improving the evaporation efficiency of the solution while simultaneously recovering heat from the steam in the evaporator, thus increasing the device's heat utilization efficiency. Vibration shakes off crystals adhering to the stirring rod, allowing for automatic cleaning of the rod and facilitating easy cleaning. The crystals are then filtered, dried, and recovered, improving processing efficiency and saving the cost of setting up multiple processing devices.

[0008] To achieve the above-mentioned technical effects, this utility model provides a concentration and crystallization equipment for the production of ammonium phosphate products, including a main steam inlet pipe, a main steam outlet pipe, a solution inlet pipe, an evaporator, a thickener, and a control cabinet. The evaporator is located on the left side of the thickener, the main steam inlet pipe is located above the left side of the evaporator, the main steam outlet pipe is located below the left side of the evaporator, the solution inlet pipe is located at the front of the evaporator, and the control cabinet is located outside the evaporator and is electrically connected to the evaporator and the thickener. A flash evaporator is also provided on the right side of the evaporator. The flash evaporator is connected to the outlet below the evaporator via a pipe through its left inlet, and a water pump valve group a is provided on the pipe. The lower outlet of the flash evaporator is connected to the left inlet of the thickener via a pipe. The front of the flash evaporator is connected to the evaporation steam outlet pipe on the right side of the evaporator via a pipe. An exhaust pipe is provided on the right side of the flash evaporator. The flash evaporator is electrically connected to the control cabinet. The thickener also includes a stirring mechanism, a thickening tank, and a crystallization device. The stirring mechanism, which can be vibrated and automatically cleaned, is located above the thickening tank, and a crystallization device, which can filter and dry crystals, is located below the thickening mechanism.

[0009] Preferably, the flash evaporation device further includes a flash evaporation tank, an insulation coil, a pressure sensor, a negative pressure vacuum machine a, and a water pump valve group b. The insulation coil is respectively installed inside the side of the flash evaporation tank, the pressure sensor is respectively installed on the left side of the flash evaporation tank, the negative pressure vacuum machine a is installed on the rear side of the flash evaporation tank, and the water pump valve group b is installed on the pipeline between the flash evaporation device and the thickening device below. An insulation layer is installed on the outside of the insulation coil.

[0010] Preferably, the flash tank further includes a grading chamber, an electric valve a, and a connecting pipe. The grading chambers are connected by the connecting pipe, and the electric valve a is installed on the connecting pipe.

[0011] Preferably, the insulation coil further includes a steam distribution pipe, a steam collection pipe, and a drain valve assembly. The steam distribution pipe is located on the front side of the insulation coil and is connected to the insulation coil via a branch pipe. The steam collection pipe is located on the right side of the insulation coil and is connected to the insulation coil via a branch pipe. The drain valve assembly is located below the steam collection pipe.

[0012] Preferably, the stirring mechanism further includes a drive motor a, a stirring rod, a spring base, a mounting plate, and a vibration motor. The spring base is positioned above the thickening tank, the mounting plate is positioned above the spring base, the vibration motor is positioned to the right of the mounting plate, the drive motor a is positioned above the spring base, and the stirring rod is positioned below the drive motor a.

[0013] Preferably, the crystallization apparatus further includes a negative pressure separator, a scraping mechanism, a drying hopper, and a material box. The negative pressure separator is located below the thickening tank, the scraping mechanism is located behind the negative pressure separator, the material box is located below the scraping mechanism, and the drying hopper is located above the negative pressure separator on the right side.

[0014] Preferably, the negative pressure separator further includes a top cover, a filter plate, a negative pressure chamber, a negative pressure pipe, a vacuum chamber, a negative pressure vacuum motor b, a mounting shaft, a drive motor b, and a mounting base. The top cover is located above the filter plate and is slidably connected to it. The negative pressure chamber is located below the filter plate. The negative pressure pipe is located below the filter plate and is connected to the top cover of the vacuum chamber. The top cover of the vacuum chamber is slidably connected to the vacuum chamber. The bottom of the vacuum chamber is fixedly mounted on the mounting base. The negative pressure vacuum motor b is located on the right side of the vacuum chamber. The mounting shaft is located in the middle of the filter plate. The bottom of the mounting shaft is connected to the output end of the drive motor b. The drive motor b is mounted on the mounting base. The output end of the drive motor b passes upward through the vacuum chamber and connects to the bottom of the mounting shaft.

[0015] Preferably, the scraping mechanism further includes a drive motor c, a mounting rod, a roller, a transmission belt, a scraper, and a hopper. The mounting rod is disposed on the side of the upper cover, the roller is rotatably disposed between the mounting rods, the transmission belt is disposed on the outside of the roller, the scraper is disposed on the upper and lower sides of the transmission belt device, the hopper is disposed below the rear side of the transmission belt, the drive motor c is disposed on the right side of the mounting rod, and the output end of the drive motor c is connected to the roller.

[0016] Preferably, the inner side of the upper cover is further provided with a scraper bar, which is located on the left side of the scraping mechanism.

[0017] Preferably, an air heater is installed on the top of the drying hopper, and a heating coil inside the air heater heats the air. The inlet end of the heating coil is connected to the steam collection pipe through a pipe, and an induced draft fan is installed at the rear end of the air heater.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] The device is equipped with a flash evaporation unit, which continuously processes the solution through a staged flash evaporation process, improving the evaporation efficiency of the solution. Simultaneously, it recovers heat from the steam in the evaporator, increasing the device's heat utilization efficiency. A spring base, mounting plate, and vibration motor are included to shake off crystals from the stirring rod, allowing for automatic and convenient cleaning. A crystallization unit is also included to filter, dry, and recover the crystals, improving processing efficiency and saving the cost of setting up multiple processing units. Attached Figure Description

[0020] Figure 1 This is an isometric view of the present invention;

[0021] Figure 2 This is a front view of the present invention;

[0022] Figure 3 yes Figure 2 A sectional view of section a.

[0023] Figure 4 This is the left view of this utility model;

[0024] Figure 5 yes Figure 4 A sectional view of section b in the middle;

[0025] The attached diagram lists the components represented by each number as follows:

[0026] 1. Main steam inlet pipe; 2. Main steam outlet pipe; 3. Solution inlet pipe; 4. Evaporator; 5. Thickener; 6. Flash evaporator; 7. Pump valve assembly a; 8. Exhaust pipe; 9. Stirring mechanism; 10. Thickening tank; 11. Crystallizer; 12. Insulation coil; 13. Pressure sensor; 14. Negative pressure vacuum machine a; 15. Pump valve assembly b; 16. Classification chamber; 17. Electric valve a; 18. Connecting pipe; 19. Steam distribution pipe; 20. Steam collection pipe; 21. Drainage duct 21. Valve assembly; 22. Drive motor a; 23. Stirring rod; 24. Spring base; 25. Mounting plate; 26. Vibrating motor; 27. Drying hopper; 28. Material box; 29. ​​Top cover; 30. Filter plate; 31. Negative pressure chamber; 32. Negative pressure pipeline; 33. Vacuum chamber; 34. Negative pressure vacuum machine b; 35. Mounting shaft; 36. Drive motor b; 37. Mounting base; 38. Drive motor c; 39. Mounting rod; 40. Transmission belt; 41. Scraper; 42. Hopper; 43. Scraper rod. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0028] The prior art in this embodiment has the following problems: The inventors have found the following defects in the prior art: 1. The device uses negative pressure to lower the boiling point of the solution to evaporate the solvent. During the evaporation process, the evaporated steam carries away some heat, causing the solution temperature to drop. The solution needs to absorb heat from the heating steam again, and the solution continues to boil, increasing energy consumption and making it difficult to maintain the efficient evaporation effect of the solvent. 2. The concentrated solution enters the thickener for crystallization. The crystals precipitated at the outlet of the thickener need to be filtered and dried in other devices to obtain the finished product. This requires two additional processes and equipment to perform separation and drying operations, which increases production costs. 3. The thickener is equipped with a stirring rod. During the process of stirring the concentrated liquid to accelerate crystallization and sedimentation, some crystals will stand on the surface of the stirring rod. These crystals continue to adhere to the stirring rod and are difficult to clean after long-term accumulation. Example 1

[0029] like Figures 1 to 5 As shown:

[0030] Therefore, the inventor provides a concentration and crystallization device for the production of ammonium phosphate products, including a main steam inlet pipe 1, a main steam outlet pipe 2, a solution inlet pipe 3, an evaporator 4, a thickener 5, and a control cabinet. The evaporator 4 is located to the left of the thickener 5, the main steam inlet pipe 1 is located above the left side of the evaporator 4, the main steam outlet pipe 2 is located below the left side of the evaporator 4, the solution inlet pipe 3 is located in front of the evaporator 4, and the control cabinet (not shown in the figure) is located outside the evaporator 4 and is electrically connected to the evaporator 4 and the thickener 5. A flash evaporation device 6 is also provided on the right side of the evaporator 4, and the flash evaporation device 6 is connected to the left side of the evaporator 4. The inlet on the side is connected to the outlet below the evaporator 4 via a pipe, and a water pump valve group a7 is installed on the pipe. The lower outlet of the flash evaporator 6 is connected to the left inlet of the thickener 5 via a pipe. The front side of the flash evaporator 6 is connected to the steam outlet pipe on the right side of the evaporator 4 via a pipe. An exhaust pipe 8 is installed on the right side of the flash evaporator 6. The flash evaporator 6 is electrically connected to the control cabinet. The thickener 5 also includes a stirring mechanism 9, a thickening tank 10, and a crystallizing device 11. The stirring mechanism 9, which can be vibrated and automatically cleaned, is installed above the thickening tank 10. The crystallizing device 11, which can filter and dry crystals, is installed below the thickening mechanism.

[0031] Using the above scheme, the prepared and mixed phosphoric acid solution enters the evaporator 4 from the solution inlet pipe 3. The steam from the production workshop enters the internal heat exchange pipe of the evaporator 4 from the main steam inlet pipe 1. The solution in the evaporator 4 is heated by heat exchange, and the heated steam flows out from the main steam outlet pipe 2. After the solution in the evaporator 4 is heated and evaporated, the steam enters the flash evaporator 6 from the evaporation steam outlet pipe on the right side of the evaporator 4. After evaporation and heat exchange in the flash evaporator 6, it is discharged. After the solution in the evaporator 4 is heated to the saturation temperature, it is discharged downward into the flash evaporator 6 under the control of the control cabinet. After evaporation from top to bottom in the flash evaporator 6, the concentrated solution is discharged downward into the thickener 5. After being stirred and crystallized by the stirring mechanism 9, the crystallized crystals are precipitated downward by centrifugal force. The precipitated crystals are discharged downward into the crystallization device 11. After filtration to separate the solution and crystals, the crystals are dried to obtain the finished crystals. Example 2

[0032] like Figures 1 to 5 As shown:

[0033] Furthermore, the flash evaporation device 6 also includes a flash evaporation tank, an insulation coil 12, a pressure sensor 13, a negative pressure vacuum machine a14, and a water pump valve group b15. The insulation coil 12 is respectively located inside the side of the flash evaporation tank, the pressure sensor 13 is respectively located on the left side of the flash evaporation tank, the negative pressure vacuum machine a14 is located on the rear side of the flash evaporation tank, and the water pump valve group b15 is located on the pipeline between the flash evaporation device 6 and the thickening device. An insulation layer is provided on the outside of the insulation coil 12.

[0034] Furthermore, the flash tank also includes a grading chamber 16, an electric valve a17, and a connecting pipe 18. The grading chambers 16 are connected to each other through the connecting pipe 18, and the electric valve a17 is installed on the connecting pipe 18.

[0035] Furthermore, the insulation coil 12 also includes a steam distribution pipe 19, a steam collection pipe 20, and a steam trap assembly 21. The steam distribution pipe 19 is located on the front side of the insulation coil 12 and is connected to the insulation coil 12 by a branch pipe. The steam collection pipe 20 is located on the right side of the insulation coil 12 and is connected to the insulation coil 12 by a branch pipe. The steam trap assembly 21 is located below the steam collection pipe 20.

[0036] Before the solution in evaporator 4 enters flash evaporator 6, the negative pressure vacuum pump a14 is activated to evacuate the different chambers in the grading chamber 16 to a vacuum state. The grading chambers 16 are arranged in descending order. The electric valve a17 on the connecting pipe 18 between the different chambers is closed. The saturated solution is pumped by the water pump valve group a7 to the uppermost grading chamber 16. The saturated solution is affected by the low pressure in the chamber, causing the solvent to evaporate. The evaporated solvent is discharged from the exhaust pipe 8 on the right side of the grading chamber 16. After a portion of the solution in the upper grading chamber 16 has evaporated, the electric valve a17 between the grading chambers 16 is opened to further reduce the pressure in the grading chamber 16. The solution falls through the connecting pipe to the upper grading chamber 6. In the next layer of the graded chamber 16, the pressure is reduced and evaporated. The solution is then placed downwards into the lowest graded chamber 16 to evaporate the solvent in the solution. When the solution falls into the lower graded chamber 16, the electric valve a17 on the connecting pipe between the upper and lower graded chambers 16 is closed. The vacuum pump a14 of the upper graded chamber 16 evacuates the chamber to receive the next batch of solution. After the solution in the lower graded chamber 16 is discharged downwards, the electric valve a17 on the connecting pipe of the lower graded chamber 16 is closed. After the vacuum pump a14 evacuates the chamber, the solution is processed in the same way. Each graded chamber 16 is equipped with a steam exhaust pipe 8 to discharge the evaporated solvent vapor.

[0037] During the flash evaporation process, the evaporated solvent in the evaporator 4 enters the insulation coil 12 through the steam distribution pipe 19 on the front side of the insulation coil 12. The heat is used to maintain the temperature inside the flash evaporation chamber, recover the heat from the steam, and ensure the evaporation efficiency of the solution. The steam after heat recovery is discharged from the side of the insulation coil 12 through the steam collection pipe 20. The condensate generated during the process is discharged into the wastewater tank through the condensate trap group 21 below the steam collection pipe 20. The solution is continuously processed by the staged flash evaporation device 6 to improve the evaporation efficiency of the evaporation solution. At the same time, the heat from the steam in the evaporator 4 is recovered and used to increase the heat utilization efficiency of the device. Example 3

[0038] like Figures 1 to 5 As shown:

[0039] Furthermore, the stirring mechanism 9 also includes a drive motor a22, a stirring rod 23, a spring base 24, a mounting plate 25, and a vibration motor 26. The spring base 24 is positioned above the thickening tank 10, the mounting plate 25 is positioned above the spring base 24, the vibration motor 26 is positioned to the right of the mounting plate 25, the drive motor a22 is positioned above the spring base 24, and the stirring rod 23 is positioned below the drive motor a22.

[0040] In the thickening tank 10, the drive motor a22 drives the stirring rod 23 to agitate the solution, causing the solute in the solution to crystallize. Under the action of its own weight and centrifugal stirring, the crystals settle downwards. During the process, the crystals adhering to the stirring rod 23 settle down. After the solution in the thickener 5 is processed, the vibration motor 26 is started, which drives the stirring rod 23 at the front end of the drive motor a22 to vibrate on the spring base 24 through the mounting plate 25, shaking off the crystals on the stirring rod 23. The vibration shakes off the crystals adhering to the stirring rod 23, so that the stirring rod 23 can be automatically cleaned, which is convenient. Example 4

[0041] like Figures 1 to 5 As shown:

[0042] Furthermore, the crystallization device 11 also includes a negative pressure separator, a scraping mechanism, a drying hopper 27, and a material box 28. The negative pressure separator is located below the thickening tank 10, the scraping mechanism is located behind the negative pressure separator, the material box 28 is located below the scraping mechanism, and the drying hopper 27 is located above the negative pressure separator on the right side.

[0043] Furthermore, the negative pressure separator also includes an upper cover 29, a filter plate 30, a negative pressure chamber 31, a negative pressure pipe 32, a vacuum chamber 33, a negative pressure vacuum machine b34, a mounting shaft 35, a drive motor b36, and a mounting base 37. The upper cover 29 is located above the filter plate 30 and is slidably connected to the filter plate 30. The negative pressure chamber 31 is located below the filter plate 30. The negative pressure pipe 32 is located below the filter plate 30 and is connected to the upper cover plate of the vacuum chamber 33. The upper cover plate of the vacuum chamber 33 is slidably connected to the vacuum chamber 33. The lower part of the vacuum chamber 33 is fixedly mounted on the mounting base 37. The negative pressure vacuum machine b34 is located on the right side of the vacuum chamber 33. The mounting shaft 35 is located in the middle of the filter plate 30. The lower part of the mounting shaft 35 is connected to the upper output end of the drive motor b36. The drive motor b36 is mounted on the mounting base 37. The output end of the drive motor b36 passes upward through the vacuum chamber 33 and is connected to the bottom of the mounting shaft 35.

[0044] Furthermore, the scraping mechanism also includes a drive motor c38, a mounting rod 39, a roller, a transmission belt 40, a scraper 41, and a hopper 42. The mounting rod 39 is disposed on the side of the upper cover 29, the roller (not shown in the figure) is rotatably disposed between the mounting rods 39, the transmission belt 40 is disposed on the outside of the roller, the scraper 41 is disposed on the upper and lower sides of the transmission belt 40, the hopper 42 is disposed below the rear side of the transmission belt 40, the drive motor c38 is disposed on the right side of the mounting rod 39, and the output end of the drive motor c38 is connected to the roller.

[0045] Furthermore, the inner side of the upper cover 29 is also provided with a scraper rod 43, which is located on the left side of the scraping mechanism;

[0046] After the solution in the thickener 5 has crystallized and settled, the pipe below the thickener 5 is opened, and the solution containing crystals is placed above the filter plate 30. The drive motor b36 drives the filter plate 30 on the mounting shaft 35 to rotate. The negative pressure chamber 31 and the negative pressure pipe 32 below the filter plate 30 slide on the upper cover 29 above the vacuum chamber 33. The negative pressure vacuum machine b34 evacuates the vacuum chamber 33, causing the solution above the filter plate 30 to enter the negative pressure chamber 31 through the holes in the filter plate 30. The negative pressure pipe 32 enters the negative pressure chamber 31 downwards, and the negative pressure vacuum machine b34 extracts the solution, leading to the recovery tank (not shown in the figure). The crystals remain on the filter plate 30 after filtration and are driven to the right by the rotation of the filter plate 30. During rotation, the drying hopper 27 above the top cover 29 introduces hot air from the air heating equipment downwards to dry the moisture on the crystals. The hot air carrying the water vapor is discharged downwards by the negative pressure vacuum machine b34. The dried crystals come to the bottom of the scraping mechanism. The drive motor c38 on the scraping mechanism drives the transmission belt 40 on the roller to rotate, causing the scraper 41 to rotate and scrape the crystals off the filter plate 30. The crystals near the inner side of the mounting shaft 35 are scraped off by the scraper rod 43 on the top cover 29, and then hung outwards by the scraper 41 onto the hopper 42, and collected by the hopper 42 into the material box 28 to complete the recycling. By setting a mechanism below the thickening device to filter, dry and recycle the crystals, the processing efficiency is improved and the cost of setting up multiple processing devices is saved. Example 5

[0047] like Figures 1 to 5 As shown:

[0048] Furthermore, an air heater (not shown in the figure) is installed on the top of the drying hopper 27. The heating coil (not shown in the figure) inside the air heater heats the air. The inlet end of the heating coil is connected to the steam collection pipe 20 through a pipe. An induced draft fan (not shown in the figure) is installed at the rear end of the air heater.

[0049] The upper pipe of the drying hopper 27 can also be connected to an air heater. The air heater can use the steam in the steam collection pipe 20 to heat the air introduced by the induced draft fan through the heating coil, and the hot air produced will dry the filtered crystals, increasing the utilization efficiency of waste heat.

[0050] In summary, this device is equipped with a flash evaporation unit 6, which continuously processes the solution through a staged flash evaporation unit 6, improving the evaporation efficiency of the evaporation solution. At the same time, it recovers and utilizes the heat from the steam in the evaporator 4, increasing the heat utilization efficiency of the device. It is equipped with a spring base 24, a mounting plate 25, and a vibration motor 26 to shake off the crystals on the stirring rod 23. The vibration shakes off the crystals attached to the stirring rod 23, making the stirring rod 23 automatically cleaned and convenient. It is equipped with a crystallization unit 11 to filter, dry, and recover the crystals, improving processing efficiency and saving the cost of setting up multiple processing units.

[0051] The working principle of this utility model:

[0052] The prepared and mixed phosphoric acid solution enters the evaporator 4 through the solution inlet pipe 3. The steam from the production workshop enters the internal heat exchange pipe of the evaporator 4 through the main steam inlet pipe 1. The solution in the evaporator 4 is heated by heat exchange. The heated steam flows out through the main steam outlet pipe 2. After the solution in the evaporator 4 is heated and evaporated, the steam enters the flash evaporator 6 through the evaporation steam outlet pipe on the right side of the evaporator 4. After evaporation and heat exchange in the flash evaporator 6, it is discharged. After the solution in the evaporator 4 is heated to the saturation temperature, it is discharged downward into the flash evaporator 6 under the control of the control cabinet.

[0053] Before the solution in evaporator 4 enters flash evaporation device 6, the negative pressure vacuum pump a14 is activated to evacuate the different chambers in the grading chamber 16 to a vacuum state. The grading chambers 16 are arranged in descending order. The electric valve a17 on the connecting pipe 18 between the different chambers is closed. The saturated solution is pumped by the water pump valve group a7 to the uppermost grading chamber 16. The saturated solution is affected by the low pressure in the chamber, causing the solvent to evaporate. The evaporated solvent is discharged from the exhaust pipe 8 on the right side of the grading chamber 16. When part of the solution in the upper grading chamber 16 has evaporated, the electric valve a17 between the grading chambers 16 is opened to further reduce the pressure in the grading chamber 16. The solution falls to the next grading chamber through the connecting pipe. In the layered chamber 16, pressure reduction evaporation is performed, and the solution is sequentially placed downward into the bottom layered chamber 16 to evaporate the solvent in the solution. When the solution falls into the bottom layered chamber 16, the electric valve a17 on the connecting pipe between the upper layered chamber 16 and the lower layered chamber 16 is closed, and the negative pressure vacuum machine a14 of the upper layered chamber 16 evacuates the chamber to receive the next batch of solution. After the solution in the next layered chamber 16 is discharged downward, the electric valve a17 on the downward connecting pipe of the lower layered chamber 16 is closed, and the negative pressure vacuum machine a14 evacuates the chamber. The solution is processed in the same way. Each layered chamber 16 is equipped with a steam exhaust pipe 8 to discharge the evaporated solvent vapor.

[0054] During the flash evaporation process, the evaporated solvent in the evaporator 4 enters the insulation coil 12 through the steam distribution pipe 19 on the front side of the insulation coil 12. The heat is used to maintain the temperature inside the flash evaporation chamber, recover the heat from the steam, and ensure the evaporation efficiency of the solution. The steam after heat recovery is discharged from the side of the insulation coil 12 through the steam collection pipe 20. The condensate generated during the process is discharged into the wastewater tank through the condensate trap group 21 below the steam collection pipe 20. The solution is continuously processed by the staged flash evaporation device 6 to improve the evaporation efficiency of the evaporation solution. At the same time, the heat from the steam in the evaporator 4 is recovered and used to increase the heat utilization efficiency of the device.

[0055] After flash evaporation, the water pump valve group b15 pumps the solution into the thickening tank 10. The drive motor a22 drives the stirring rod 23 to stir the solution, causing the solute in the solution to crystallize. Under the action of its own weight and centrifugal stirring, the crystals settle downwards. During the process, the crystals adhering to the stirring rod 23 settle down. After the solution in the thickener 5 is processed, the vibration motor 26 is started, and the stirring rod 23 at the front end of the drive motor a22 vibrates on the spring base 24 through the mounting plate 25, shaking off the crystals on the stirring rod 23. The vibration shakes off the crystals adhering to the stirring rod 23, so that the stirring rod 23 can be automatically cleaned, which is convenient.

[0056] After the solution in thickener 5 has crystallized and settled, the pipe below thickener 5 is opened, and the solution containing crystals is placed above filter plate 30. Drive motor b36 rotates filter plate 30 on mounting shaft 35. Negative pressure chamber 31 and negative pressure pipe 32 below filter plate 30 slide on upper cover 29 above vacuum chamber 33. Negative pressure vacuum pump b34 evacuates vacuum chamber 33, causing the solution above filter plate 30 to enter negative pressure chamber 31 through the pores in filter plate 30. Negative pressure pipe 32 enters negative pressure chamber 31 downwards, and negative pressure vacuum pump b34 extracts the solution, leading to a recovery tank. Crystals remain on filter plate 30 after filtration and are rotated to the right by the rotation of filter plate 30. In the middle, the drying hopper 27 above the upper cover 29 introduces hot air from the air heating equipment downwards to dry the moisture on the crystals. The hot air carrying water vapor is discharged downwards by the negative pressure vacuum machine b34. The dried crystals come to the bottom of the scraping mechanism. The drive motor c38 on the scraping mechanism drives the transmission belt 40 on the roller to rotate, causing the scraper 41 to rotate and scrape the crystals off the filter plate 30. The crystals near the inner side of the mounting shaft 35 are scraped off by the scraper rod 43 on the upper cover 29, and then scraped outwards by the scraper 41 and hung on the hopper 42. The hopper 42 collects them into the material box 28 to complete the recycling. By setting a mechanism below the thickening device to filter, dry and recycle the crystals, the processing efficiency is improved and the cost of setting up multiple processing devices is saved.

[0057] The pipe above the drying hopper 27 can also be connected to an air heater. The air heater can use the steam in the steam collection pipe 20 to heat the air introduced by the induced draft fan through the heating coil, and produce hot air to dry the filtered crystals, thereby increasing the utilization efficiency of waste heat.

[0058] This concludes the description of the working principle of the device.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0060] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A concentration and crystallization device for producing ammonium phosphate, comprising a main steam inlet pipe, a main steam outlet pipe, a solution inlet pipe, an evaporator, a thickener, and a control cabinet, wherein the evaporator is located to the left of the thickener, the main steam inlet pipe is located above the left side of the evaporator, the main steam outlet pipe is located below the left side of the evaporator, the solution inlet pipe is located at the front of the evaporator, and the control cabinet is located outside the evaporator and electrically connected to the evaporator and the thickener, characterized in that: A flash evaporator is also installed on the right side of the evaporator. The flash evaporator is connected to the outlet below the evaporator via a pipe through its left inlet, and a water pump valve group a is installed on the pipe. The lower outlet of the flash evaporator is connected to the left inlet of the thickener via a pipe. The front of the flash evaporator is connected to the evaporation steam outlet pipe on the right side of the evaporator via a pipe. An exhaust pipe is installed on the right side of the flash evaporator. The flash evaporator is electrically connected to the control cabinet. The thickener also includes a stirring mechanism, a thickening tank, and a crystallization device. The stirring mechanism, which can be vibrated and automatically cleaned, is located above the thickening tank. A crystallization device, which can filter and dry crystals, is located below the thickening mechanism. The stirring mechanism, the thickening tank, and the crystallization device are all electrically connected to the control cabinet.

2. The concentration and crystallization equipment for producing ammonium phosphate products according to claim 1, characterized in that: The flash evaporation device also includes a flash evaporation tank, an insulation coil, a pressure sensor, a negative pressure vacuum machine a, and a water pump valve group b. The insulation coil is respectively installed inside the side of the flash evaporation tank, the pressure sensor is respectively installed on the left side of the flash evaporation tank, the negative pressure vacuum machine a is installed on the rear side of the flash evaporation tank, and the water pump valve group b is installed on the pipeline between the flash evaporation device and the thickening device below. An insulation layer is installed on the outside of the insulation coil.

3. The concentration and crystallization equipment for producing ammonium phosphate products according to claim 2, characterized in that: The flash tank also includes a grading chamber, an electric valve a, and connecting pipes. The grading chambers are connected by connecting pipes, and the electric valve a is installed on the connecting pipes.

4. The concentration and crystallization equipment for producing ammonium phosphate products according to claim 2, characterized in that: The insulation coil also includes a steam distribution pipe, a steam collection pipe, and a drain valve assembly. The steam distribution pipe is located on the front side of the insulation coil and is connected to the insulation coil via a branch pipe. The steam collection pipe is located on the right side of the insulation coil and is connected to the insulation coil via a branch pipe. The drain valve assembly is located below the steam collection pipe.

5. The concentration and crystallization equipment for producing ammonium phosphate products according to claim 1, characterized in that: The stirring mechanism further includes a drive motor a, a stirring rod, a spring base, a mounting plate, and a vibration motor. The spring base is positioned above the thickening tank, the mounting plate is positioned above the spring base, the vibration motor is positioned to the right of the mounting plate, the drive motor a is positioned above the spring base, and the stirring rod is positioned below the drive motor a.

6. The concentration and crystallization equipment for producing ammonium phosphate products according to claim 1, characterized in that: The crystallization apparatus further includes a negative pressure separator, a scraping mechanism, a drying hopper, and a material box. The negative pressure separator is located below the thickening tank, the scraping mechanism is located behind the negative pressure separator, the material box is located below the scraping mechanism, and the drying hopper is located on the upper right side of the negative pressure separator.

7. The concentration and crystallization equipment for producing ammonium phosphate products according to claim 6, characterized in that: The negative pressure separator further includes a top cover, a filter plate, a negative pressure chamber, a negative pressure pipe, a vacuum chamber, a negative pressure vacuum motor b, a mounting shaft, a drive motor b, and a mounting base. The top cover is located above the filter plate and is slidably connected to it. The negative pressure chamber is located below the filter plate. The negative pressure pipe is located below the filter plate and is connected to the top cover of the vacuum chamber. The top cover of the vacuum chamber is slidably connected to the vacuum chamber. The bottom of the vacuum chamber is fixedly mounted on the mounting base. The negative pressure vacuum motor b is located on the right side of the vacuum chamber. The mounting shaft is located in the middle of the filter plate. The bottom of the mounting shaft is connected to the output end of the drive motor b. The drive motor b is mounted on the mounting base. The output end of the drive motor b passes upward through the vacuum chamber and connects to the bottom of the mounting shaft.

8. The concentration and crystallization equipment for producing ammonium phosphate products according to claim 6, characterized in that: The scraping mechanism further includes a drive motor c, a mounting rod, a roller, a transmission belt, a scraper, and a hopper. The mounting rod is located on the side of the upper cover, the roller is rotatably mounted between the mounting rods, the transmission belt is located on the outside of the roller, the scraper is located on the upper and lower sides of the transmission belt device, the hopper is located below the rear side of the transmission belt, the drive motor c is located on the right side of the mounting rod, and the output end of the drive motor c is connected to the roller.

9. The concentration and crystallization equipment for producing ammonium phosphate products according to claim 7, characterized in that: The inner side of the upper cover is also provided with a scraper rod, which is located on the left side of the scraping mechanism.

10. A concentration and crystallization apparatus for producing ammonium phosphate products according to claim 6, characterized in that: An air heater is installed on the top of the drying hopper. The air heater has a heating coil inside that heats the air. The inlet end of the heating coil is connected to the steam collection pipe through a pipe. An induced draft fan is installed at the rear end of the air heater.

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