Phosphogypsum heat treatment modification device

Abstract

The utility model relates to a kind of phosphogypsum heat treatment modification devices, belong to phosphogypsum processing technical field.It includes feeding system, and feeding system includes feed hopper, and feed hopper bottom is equipped with discharge pipe, and discharge pipe is equipped with discharge monitoring mechanism on, and feed hopper is also equipped with anti-blocking mechanism in, and discharge pipe one end is equipped with conveying mechanism, and conveying mechanism one end is rotatably installed with rotary kiln, and rotary kiln is equipped with atmosphere control system on, and the burner of rotary kiln other end is equipped with, and rotary kiln other end is also equipped with cooling system, and the cooling system one end is equipped with receiving hopper.The utility model is equipped with discharge monitoring mechanism on discharge pipe, whether discharge pipe is blocked during discharging process can be monitored, if there is blockage, can be found in time and handle through anti-blocking mechanism, ensure normal discharging.Prevent phosphogypsum from adhering and accumulating in feed hopper, avoid forming "bridge" phenomenon.

Description

Technical Field

[0001] This utility model belongs to the field of phosphogypsum treatment technology, specifically relating to a phosphogypsum heat treatment modification device. Background Technology

[0002] Phosphogypsum's main component is calcium sulfate dihydrate (CaSO4·2H2O), but it contains impurities such as phosphorus, fluorine, and organic matter. Direct use of phosphogypsum results in problems such as low strength, poor water resistance, and excessive radioactivity, limiting its large-scale application in the building materials industry. Currently, the comprehensive utilization rate of phosphogypsum is only about 30%, far lower than the utilization level in developed countries.

[0003] Heat treatment modification technology is an effective way to improve the crystal structure and engineering properties of phosphogypsum by controlling temperature and atmosphere conditions to induce physicochemical changes such as dehydration, decomposition, and recrystallization. Currently, there is a lack of phosphogypsum heat treatment equipment capable of controlling the atmosphere and providing continuous processing, which is insufficient to meet the needs of large-scale industrial processing. Furthermore, phosphogypsum needs to be transported to the rotary kiln via a feeding system. However, in existing phosphogypsum feeding systems, the feed hoppers are mostly conical-bottom structures, which cause phosphogypsum to easily adhere and accumulate on the inner wall of the hopper, forming a "bridging" phenomenon (i.e., the material is suspended in the hopper and cannot fall). The discharge pipe, due to its small diameter and uneven material flow rate, is prone to blockage by lumpy phosphogypsum, leading to interrupted feeding. Therefore, there is an urgent need for a phosphogypsum heat treatment modification device that can efficiently achieve phosphogypsum heat treatment modification, solve the problems of feed hopper bridging and discharge pipe blockage, and ensure continuous and stable feeding of phosphogypsum. Summary of the Invention

[0004] To overcome the problems mentioned in the background art, this utility model provides a heat treatment modification device for phosphogypsum. This utility model can prevent phosphogypsum from adhering and accumulating in the feed hopper, avoiding the formation of a "bridging" phenomenon.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: A phosphogypsum heat treatment modification device includes a feeding system 1, the feeding system 1 includes a feeding hopper 2, a discharge pipe 3 is installed at the bottom of the feeding hopper 2, a discharge monitoring mechanism 4 is installed on the discharge pipe 3, an anti-blocking mechanism 5 is also installed inside the feeding hopper 2, a conveying mechanism 6 is installed at one end of the discharge pipe 3, a rotary kiln 7 is rotatably installed at one end of the conveying mechanism 6, an atmosphere control system 8 is installed on the rotary kiln 7, a burner 9 is installed at the other end of the rotary kiln 7, a cooling system 10 is also installed at the other end of the rotary kiln 7, and a receiving hopper 11 is installed at one end of the cooling system 10.

[0006] Furthermore, the anti-blocking mechanism 5 includes a stirring motor 12, a stirring shaft 13, stirring rods 14, a driving bevel gear 15, a driven bevel gear 16, and a vibration mechanism 17. The stirring motor 12 is installed on the top of the feed hopper 2. The driving bevel gear 15 is installed on the output shaft of the stirring motor 12 via a rotating shaft. The stirring shaft 13 is a hollow shaft. The stirring shaft 13 is rotatably installed inside the feed hopper 2, and one end of the stirring shaft 13 extends to the outside of the top of the feed hopper 2 and is equipped with a driven bevel gear 16. The driven bevel gear 16 meshes with the driving bevel gear 15. Multiple stirring rods 14 are installed on the stirring shaft 13, and the vibration mechanism 17 is installed on the feed hopper 2.

[0007] Furthermore, the vibration mechanism 17 includes an electric cylinder 18 and a vibration rod 19. A support frame 20 is installed on the top of the feed hopper 2, and the electric cylinder 18 is installed on the support frame 20. The telescopic end of the electric cylinder 18 extends into the stirring shaft 13, and the vibration rod 19 is installed on the telescopic end of the electric cylinder 18.

[0008] Furthermore, the feeding monitoring mechanism 4 includes a monitoring tube 21 and a microwave sensor 22. The monitoring tube 21 is detachably installed at one end of the feeding tube 3, and the microwave sensor 22 is installed on the monitoring tube 21.

[0009] Furthermore, the monitoring tube 21 includes a left half tube 23 and a right half tube 24, and the feeding tube 3 includes an upper section tube 25 and a lower section tube 26. One end of the upper section tube 25 is installed at the bottom of the feeding hopper 2, and the lower section tube 26 is installed on the conveying mechanism 6. Both the upper section tube 25 and the lower section tube 26 have notches at their adjacent ends. The left half tube 23 and the right half tube 24 are installed on the notches, and both the left half tube 23 and the right half tube 24 have fixing blocks with screw holes.

[0010] Furthermore, the atmosphere control system 8 includes a gas storage tank 27 and a gas distribution pipeline 28. One end of the gas distribution pipeline 28 is connected to the gas storage tank 27, and the other end extends into the rotary kiln 7. The end of the gas distribution pipeline 28 extending into the rotary kiln 7 is provided with multiple through holes.

[0011] Furthermore, the cooling system 10 includes a rapid cooling mechanism 29 and a slow cooling mechanism 30. The rapid cooling mechanism 29 is installed at one end of the rotary kiln 7, and the slow cooling mechanism 30 is installed at one end of the rapid cooling mechanism 29.

[0012] The beneficial effects of this utility model are: This invention enables the orderly modification of phosphogypsum, significantly improving product strength and water resistance while ensuring purity and performance stability. The combination of rapid cooling and slow cooling mechanisms ensures rapid setting of the modified phosphogypsum and maintains a good crystal structure, resulting in stable and reliable product quality. Simultaneously, a feeding monitoring mechanism is installed on the feeding pipe to detect blockages during the feeding process. If a blockage occurs, it can be detected promptly and addressed through an anti-blocking mechanism to ensure normal feeding. The stirring rod of the anti-blocking mechanism agitates the phosphogypsum, preventing it from adhering and accumulating in the feed hopper, thus avoiding "bridging." Under the action of an electric cylinder, a vibrating rod reciprocates, vibrating the phosphogypsum and preventing its accumulation and blockage in the feeding pipe. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model.

[0014] Figure 2 yes Figure 1 Enlarged schematic diagram of part A in the middle.

[0015] Figure 3 This is a cross-sectional schematic diagram of the feed hopper structure of this utility model.

[0016] Reference numerals in the figures: 1. Feeding system; 2. Feed hopper; 3. Feeding pipe; 4. Feeding monitoring mechanism; 5. Anti-blocking mechanism; 6. Conveying mechanism; 7. Rotary kiln; 8. Atmosphere control system; 9. Burner; 10. Cooling system; 11. Receiving hopper; 12. Stirring motor; 13. Stirring shaft; 14. Stirring rod; 15. Driving bevel gear; 16. Vibration mechanism; 17. Electric cylinder; 18. Vibration rod; 19. Support frame; 20. Monitoring pipe; 21. Microwave sensor; 22. Left half pipe; 23. Right half pipe; 24. Upper section pipe; 25. Lower section pipe; 26. Gas storage tank; 27. Gas distribution pipeline; 28. Rapid cooling mechanism; 29. ​​Slow cooling mechanism; 30. Conveying pipe; 31. Screw conveyor structure; 32. Purification pipe; 33. Cyclone dust collector; 34. Bag dust collector; 35. Exhaust fan; 36. Rapid cooling cylinder; 37. Cooling fan; 38. Slow cooling pipe; 39. Detailed Implementation

[0017] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, so as to facilitate the understanding of those skilled in the art.

[0018] like Figure 1-3This utility model discloses a heat treatment modification device for phosphogypsum. The device includes a feeding system 1, which comprises a feeding hopper 2. A discharge pipe 3 is installed at the bottom of the feeding hopper 2, and a discharge monitoring mechanism 4 is installed on the discharge pipe 3. An anti-blocking mechanism 5 is also installed inside the feeding hopper 2. A conveying mechanism 6 is installed at one end of the discharge pipe 3, and a rotary kiln 7 is rotatably mounted at one end of the conveying mechanism 6. The rotary kiln 7 includes a kiln head, a kiln body, and a kiln tail. The front end of the kiln body is rotatably mounted on the kiln head, and its rear end is rotatably mounted on the kiln tail. A rotating structure, which is a conventional structure used on rotary kilns, is installed at the bottom of the kiln body. One end of the conveying pipe extends into the kiln body through the kiln head. The kiln tail has an open bottom design, and a rapid cooling mechanism 29 is installed at the kiln tail. The rotary kiln 7 is also equipped with an atmosphere control system 8. A burner 9 is installed at the other end of the rotary kiln 7. The burner 9 has an existing structure, and multiple burners can be used, including those using natural gas or coal gas as fuel. The burner is installed at the kiln tail end. The temperature inside the kiln increases sequentially from the kiln head to the kiln tail end, consisting of a preheating section, a first heating zone, a second heating zone, a third heating zone, and a fourth heating zone. The preheating section temperature is 100-200°C, mainly used for pre-drying phosphogypsum and removing surface moisture. The first heating zone temperature is 200-400°C, mainly removing the water of crystallization from the phosphogypsum, converting dihydrate calcium sulfate to hemihydrate calcium sulfate. The second heating zone temperature is 400-600°C, decomposing organic impurities and some phosphate impurities. The third heating zone temperature is 600-800°C, achieving crystal structure recombination and forming a more stable crystal form. The fourth heating zone temperature is 800-900°C, completing the complete modification treatment of the phosphogypsum. Meanwhile, multiple high-temperature resistant temperature sensors are installed inside the kiln to monitor the temperature inside the kiln and ensure that the temperature of each heating section is within the required range.

[0019] A cooling system 10 is also installed at the other end of the rotary kiln 7, and a receiving hopper 11 is installed at one end of the cooling system 10. The feeding hopper 1 has a feed inlet for easy conveying of phosphogypsum. The phosphogypsum falls into the conveying mechanism 6 through the discharge pipe. The conveying mechanism 6 includes a conveying pipe 31 and a screw conveying structure 32. The screw conveying structure 32 is an existing structure, including a screw conveying motor, a conveying shaft, and screw conveying blades. The screw conveying motor is installed at one end of the conveying pipe, and its output shaft is connected to a conveying shaft extending into the conveying pipe. The screw conveying blades are installed on the conveying shaft. The device is controlled by a PLC control system. A purification pipe 33 extending into the kiln body is also provided at the kiln head. One end of the purification pipe 33 is connected to a cyclone dust collector 34, and one end of the cyclone dust collector 34 is connected to a bag filter 35 through a pipe. One end of the bag filter 35 is connected to an induced draft fan 36 through a pipe. The cyclone dust collector 34, as a primary dust removal device, has a dust removal efficiency of ≥95% and mainly removes larger dust particles. The bag filter 35 serves as a secondary dust collection device, achieving a dust removal efficiency of ≥99.5%, ensuring the effective capture of fine dust. The induced draft fan 36 provides power to the entire purification process, creating a negative pressure operating environment to prevent dust leakage. All dust and exhaust gases generated during the phosphogypsum heat treatment and modification process are treated by the aforementioned dust collection and purification processes before being discharged in compliance with standards.

[0020] The anti-blocking mechanism 5 includes a stirring motor 12, a stirring shaft 13, stirring rods 14, a driving bevel gear 15, a driven bevel gear 16, and a vibration mechanism 17. The stirring motor 12 is installed on the top of the feed hopper 2. The driving bevel gear 15 is installed on the output shaft of the stirring motor 12 via a rotating shaft. The stirring shaft 13 is a hollow shaft and is rotatably installed inside the feed hopper 2. One end of the stirring shaft 13 extends to the outside of the top of the feed hopper 2 and is equipped with a driven bevel gear 16. The driven bevel gear 16 meshes with the driving bevel gear 15. Multiple stirring rods 14 are installed on the stirring shaft 13. The vibration mechanism 17 is installed on the feed hopper 2.

[0021] The vibration mechanism 17 includes an electric cylinder 18 and a vibration rod 19. A support frame 20 is installed on the top of the feed hopper 2. The electric cylinder 18 is installed on the support frame 20, and the telescopic end of the electric cylinder 18 extends into the stirring shaft 13. The vibration rod 19 is installed on the telescopic end of the electric cylinder 18.

[0022] The feeding monitoring mechanism 4 includes a monitoring tube 21 and a microwave sensor 22. The monitoring tube 21 is detachably installed at one end of the feeding tube 3, and the microwave sensor 22 is installed on the monitoring tube 21. The microwave sensor is a reflective microwave sensor. The microwave sensor 22, the stirring motor 12, and the electric cylinder 18 are all electrically connected to the PLC control system of this device.

[0023] During the feeding process, the phosphogypsum can be stirred to prevent blockage. During the unloading process, microwave sensor 22 monitors whether the unloading is normal. Its core principle is to utilize the reflection characteristics of microwaves. By detecting the signal change after the microwave emitted by the sensor is reflected by the phosphogypsum, it determines whether there is a continuous flow of phosphogypsum in the unloading pipe, thus distinguishing between three states: "normal unloading," "blockage," and "discontinuity." When the unloading pipe is unblocked: phosphogypsum continuously passes through the monitoring area of ​​the microwave sensor. After the microwave irradiates the surface of the phosphogypsum, diffuse reflection occurs, and the receiver continuously receives an "unstable but present reflected signal" (signal strength fluctuates within a certain range). When the unloading pipe is blocked: phosphogypsum accumulates in the unloading pipe, completely blocking the microwave propagation path. The reflected signal suddenly increases and remains stable (without fluctuation). When the unloading pipe is discontinuous: there is no phosphogypsum in the unloading pipe. The microwave directly irradiates the inner wall of the unloading pipe (or penetrates an empty pipe), and the reflected signal suddenly weakens to below the threshold (approaching a state of no reflection).

[0024] When the microwave sensor 22 detects "material blockage" or "material interruption," the anti-blocking mechanism 5 is activated via the PLC controller. This mechanism includes a stirring motor 12, a stirring shaft 13, a stirring rod 14, a driving bevel gear 15, a driven bevel gear 16, and a vibration mechanism 17. Starting the stirring motor 12 causes the driving bevel gear 15 to rotate, which in turn drives the driving bevel gear 16, causing the stirring shaft 13 to rotate the stirring rod 14, thus stirring the phosphogypsum and preventing it from adhering and accumulating, preventing it from falling. Simultaneously, the electric cylinder 18 of the vibration mechanism 17 is activated, causing it to reciprocate and extend, moving the vibration rod 19 downwards. The vibration rod 19 extends into the feed pipe and reciprocates, vibrating the phosphogypsum and preventing it from accumulating and blocking the feed pipe. Furthermore, the stirring motor 12 can stir intermittently during the feeding process, enhancing the anti-blocking effect.

[0025] The monitoring tube 21 includes a left half tube 23 and a right half tube 24. The feeding tube 3 includes an upper section tube 25 and a lower section tube 26. One end of the upper section tube 25 is installed at the bottom of the feed hopper 2, and a feeding valve is installed on the upper section tube 25. The lower section tube 26 is installed on the conveying mechanism 6. Both the upper section tube 25 and the lower section tube 26 have notches at their adjacent ends. The left half tube 23 and the right half tube 24 are installed on the notches, and both the left half tube 23 and the right half tube 24 have fixing blocks with screw holes. The left half tube 23 and the right half tube 24 are fixed between the upper section tube 25 and the lower section tube 26 by bolts and fixing blocks, which facilitates disassembly and assembly and makes maintenance convenient in case of monitoring or feeding failure.

[0026] The atmosphere control system 8 includes a gas storage tank 27 and a gas distribution pipeline 28. One end of the gas distribution pipeline 28 is connected to the gas storage tank 27, and the other end extends into the rotary kiln 7. The end of the gas distribution pipeline 28 extending into the rotary kiln 7 has multiple through holes. A gas pump and an electric valve are installed on the gas distribution pipeline 28 to control the gas flow. The gas storage tank 27 stores a protective atmosphere of nitrogen or carbon dioxide. The multiple through holes on the end of the gas distribution pipeline 28 extending into the rotary kiln 7 ensure that the protective atmosphere is evenly distributed within the kiln, preventing oxidation of phosphogypsum during high-temperature treatment.

[0027] The cooling system 10 includes a rapid cooling mechanism 29 and a slow cooling mechanism 30. The rapid cooling mechanism 29 is installed at one end of the rotary kiln 7, and the slow cooling mechanism 30 is installed at the other end of the rapid cooling mechanism 29. The rapid cooling mechanism 29 includes a rapid cooling cylinder 37 with a discharge pipe, which is installed at the bottom of the kiln tail end of the rotary kiln. A cooling fan 38 is installed on the rapid cooling cylinder 37. The cooling fan 38 has a power of 15-30kW and a cooling air volume of 500-1000m³ / min, rapidly cooling the modified phosphogypsum from a high temperature to below 300°C for rapid shaping. The slow cooling mechanism 30 is a slow cooling pipe 39, installed at the bottom of the discharge pipe of the rapid cooling cylinder. A receiving hopper 11 is installed at one end of the slow cooling pipe, and a spiral conveying structure 32 is also installed on the slow cooling pipe 39 to transport the cooled phosphogypsum into the receiving hopper 11.

[0028] Work process: The working principle of this invention is as follows: phosphogypsum is fed into hopper 2 through the feed inlet on the feed hopper, falls into conveying pipe 31 through discharge pipe 3, and is then conveyed to rotary kiln 7 by screw conveyor structure 32. The phosphogypsum undergoes pre-drying treatment in the preheating section, and then sequentially passes through the first to fourth heating zones for segmented gradient heating treatment. Under the protection of nitrogen or carbon dioxide gas, the phosphogypsum undergoes physicochemical changes such as dehydration, decomposition, and recrystallization to modify its crystal structure. The treated phosphogypsum is rapidly cooled and shaped by quenching mechanism 29, then naturally cooled by slow cooling mechanism 30, and finally conveyed to receiving hopper for unloading. Simultaneously, the dust and exhaust gas generated throughout the process are treated by dust removal and purification before being discharged in compliance with standards.

[0029] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A device for heat treatment modification of phosphogypsum, characterized in that: The aforementioned phosphogypsum heat treatment modification device includes a feeding system (1), the feeding system (1) includes a feeding hopper (2), a discharge pipe (3) is installed at the bottom of the feeding hopper (2), a discharge monitoring mechanism (4) is installed on the discharge pipe (3), an anti-blocking mechanism (5) is also installed inside the feeding hopper (2), a conveying mechanism (6) is installed at one end of the discharge pipe (3), a rotary kiln (7) is rotatably installed at one end of the conveying mechanism (6), an atmosphere control system (8) is installed on the rotary kiln (7), a burner (9) is installed at the other end of the rotary kiln (7), a cooling system (10) is also installed at the other end of the rotary kiln (7), and a receiving hopper (11) is installed at one end of the cooling system (10).

2. The device for modifying phosphogypsum by heat treatment according to claim 1, characterized in that: The anti-blocking mechanism (5) includes a stirring motor (12), a stirring shaft (13), a stirring rod (14), a driving bevel gear (15), a driven bevel gear (16), and a tamping mechanism (17). The stirring motor (12) is installed on the top of the feed hopper (2). The driving bevel gear (15) is installed on the output shaft of the stirring motor (12) via a rotating shaft. The stirring shaft (13) is a hollow shaft. The stirring shaft (13) is rotatably installed inside the feed hopper (2), and one end of the stirring shaft (13) extends to the outside of the top of the feed hopper (2) where the driven bevel gear (16) is installed. The driven bevel gear (16) meshes with the driving bevel gear (15). Multiple stirring rods (14) are installed on the stirring shaft (13). The tamping mechanism (17) is installed on the feed hopper (2).

3. The device for modifying phosphogypsum by heat treatment according to claim 2, characterized in that: The tamping mechanism (17) includes an electric cylinder (18) and a tamping rod (19). A support frame (20) is installed on the top of the feed hopper (2). An electric cylinder (18) is installed on the support frame (20), and the telescopic end of the electric cylinder (18) extends into the stirring shaft (13). The tamping rod (19) is installed on the telescopic end of the electric cylinder (18).

4. The device for modifying phosphogypsum by heat treatment according to any one of claims 1 to 3, characterized in that: The feeding monitoring mechanism (4) includes a monitoring tube (21) and a microwave sensor (22). The monitoring tube (21) is detachably installed at one end of the feeding tube (3), and the microwave sensor (22) is installed on the monitoring tube (21).

5. The device for modifying phosphogypsum by heat treatment according to claim 4, characterized in that: The monitoring tube (21) includes a left half tube (23) and a right half tube (24). The feeding tube (3) includes an upper section tube (25) and a lower section tube (26). One end of the upper section tube (25) is installed at the bottom of the feeding hopper (2). The lower section tube (26) is installed on the conveying mechanism (6). The upper section tube (25) and the lower section tube (26) are provided with notches at their adjacent ends. The left half tube (23) and the right half tube (24) are installed on the notches. The left half tube (23) and the right half tube (24) are provided with fixing blocks. The fixing blocks are provided with screw holes.

6. The device for modifying phosphogypsum by heat treatment according to claim 5, characterized in that: The atmosphere control system (8) includes a gas storage tank (27) and a gas distribution pipeline (28). One end of the gas distribution pipeline (28) is connected to the gas storage tank (27), and the other end extends into the rotary kiln (7). The end of the gas distribution pipeline (28) extending into the rotary kiln (7) is provided with multiple through holes.

7. The device for modifying phosphogypsum by heat treatment according to claim 6, characterized in that: The cooling system (10) comprises a quenching mechanism (29) and a slow cooling mechanism (30), the quenching mechanism (29) is installed at one end of the rotary kiln (7), and the slow cooling mechanism (30) is installed at one end of the quenching mechanism (29).

Images