Melamine cyclic purification and refinement production device and process

Abstract

The invention discloses a production device and process for cyclic purification and refinement of melamine, the production device comprises a dissolving tank, a press filter, an air cooling tower, a centrifugal machine, a drying machine, a separator, a mother liquor tank and a slag tank, the mother liquor output end of the centrifugal machine is connected with the input end of the mother liquor tank through a pipeline; the filter residue output end of the press filter is connected with the input end of the residue pool through a pipeline, the output end of the mother liquor pool is connected with the input end of the dissolving pool through a pipeline, the press filter is connected with a cooking system, and the cooking system is used for cooking a processing cavity in the press filter. According to the invention, the mother liquor circulating passage is arranged, the mother liquor generated by the centrifugal machine enters the mother liquor tank and is circulated into the dissolving tank through a pipeline, the cooking liquor recycling passage is arranged, the used press filter is cooked by using the cooking system, and the residue liquid formed by cooking is input into the residue tank and is input into the mother liquor tank, so that the cyclic purification of melamine is realized; the utilization rate and purification rate of raw materials are improved.

Description

Technical Field

[0001] This invention relates to the field of melamine purification technology, and in particular to a melamine recycling purification and refining production apparatus and process. Background Technology

[0002] Currently, the main production processes for melamine are based on urea as the main raw material and employ four processes: high pressure, medium pressure, low pressure, and atmospheric pressure. In the production processes of high-pressure, medium-pressure, low-pressure, and atmospheric-pressure methods, crude products (i.e., substandard products) are produced. To improve raw material utilization and reduce production costs, these crude products need to be purified to meet the required purity. In existing technologies, during the purification of melamine, insoluble byproducts are filtered out using a filter press. The clean liquid after filtration flows into subsequent processes. Additionally, a centrifuge is used to separate wet material and dry it. Mother liquor is formed during centrifugation. All of these operations generate some byproducts. The inability to effectively treat byproducts such as mother liquor leads to a decrease in raw material utilization during melamine purification. Furthermore, melamine solution remains in the filter press during filtration, further reducing raw material utilization. Therefore, there is an urgent need for a melamine recycling purification and refining production device and process to solve the problem of low raw material utilization in traditional melamine purification processes. Summary of the Invention

[0003] Therefore, it is necessary to provide a melamine recycling purification and refining production device and process to address the above-mentioned technical problems. This will solve the problems that some by-products are formed during the purification process in the existing technology, and the mother liquor and other by-products cannot be effectively treated, which will lead to a decrease in the raw material utilization rate during the melamine purification process. Furthermore, melamine solution will remain in the filter press during the filtration process, which will also lead to a further decrease in the raw material utilization rate.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A melamine recycling purification and refining production apparatus includes:

[0006] The dissolving tank has a raw liquid input through an inlet at its input end and a filter press, an air-cooled tower, a centrifuge, a dryer, and a separator connected in series via pipes at its output end. The dry material output end of the separator is connected to a silo via a pipe, and the dust output end of the separator is connected to a dust collector via a pipe. The gas output end of the dust collector is connected to an exhaust stack.

[0007] The mother liquor tank and slag tank are arranged adjacent to each other and are connected by a filter assembly. The mother liquor output end of the centrifuge is connected to the input end of the mother liquor tank through a pipe. The filter cake output end of the filter press is connected to the input end of the slag tank through a pipe. The output end of the mother liquor tank is connected to the input end of the dissolving tank through a pipe.

[0008] The filter press is connected to a cooking system, which is used to cook the processing chamber in the filter press.

[0009] In a preferred embodiment of the melamine recycling purification and refining production device provided by the present invention, the cooking system includes a steam pipe, which is connected in sequence to a mother liquor tank and a dissolving tank.

[0010] In a preferred embodiment of the melamine recycling purification and refining production device provided by the present invention, a solvent aid is connected in series between the dissolving tank and the filter press, and the bottom filter residue output end of the solvent aid is connected to the input end of the residue tank.

[0011] In a preferred embodiment of the melamine recycling purification and refining production device provided by the present invention, a heater is installed on the dryer, the heater is used to input hot air into the dryer, and a pulverizer is connected in series between the dry material output end of the separator and the silo.

[0012] In a preferred embodiment of the melamine recycling purification and refining production device provided by the present invention, the dust collector is a bag filter dust collector, which includes a dust collection chamber and a bag filter mechanism installed in the dust collection chamber. The input pipe of the dust collection chamber is connected to the dust output end of the separator. The top of the dust collection chamber is connected to the exhaust stack through an output pipe. The bottom of the dust collection chamber is provided with a discharge pipe. A partition is provided in the middle of the inner cavity of the dust collection chamber, and the bag filter mechanism is installed on the partition.

[0013] In a preferred embodiment of the melamine recycling purification and refining production device provided by the present invention, the partition plate is provided with multiple filter holes, the dust removal chamber is equipped with a pulse tank, and the bag filter mechanism includes a dust removal bag corresponding to the filter holes, a baffle plate arranged around the outer ring of the dust removal bag, and a pulse head located above each dust removal bag. A solenoid valve is installed on the pulse head, and each pulse head is connected to the pulse tank. The baffle plate corresponding to the dust removal bag is rotatably connected to the partition plate. A drive assembly is installed at the corresponding position of the partition plate and the dust removal bag. The drive assembly is used to drive the baffle plate surrounding the outer ring of the dust removal bag to rotate.

[0014] In a preferred embodiment of the melamine recycling purification and refining production device provided by the present invention, each dust collection bag is provided with a lower support frame and an upper support frame stacked from bottom to top inside. A middle support rod is vertically arranged in the middle of the dust collection bag. A movable sleeve is provided at the corresponding position of the middle support rod and the lower support frame and the upper support frame. A connecting rod is rotatably connected to the outer wall of the movable sleeve. The end of the connecting rod away from the movable sleeve is rotatably connected to the corresponding lower support frame or upper support frame.

[0015] In a preferred embodiment of the melamine recycling purification and refining production device provided by the present invention, a lower proximity switch and a vibration motor are respectively provided on one side of the movable sleeve corresponding to the lower support frame, and the lower proximity switch and the vibration motor are installed with the middle support rod; an upper proximity switch is provided on one side of the movable sleeve corresponding to the upper support frame, and the upper proximity switch is installed with the middle support rod.

[0016] A preferred embodiment of the melamine recycling purification and refining production process provided by the present invention includes the following steps:

[0017] S1: Put the raw materials into the dissolving tank for dissolution. The dissolving tank is heated with steam at 92-96℃ and stirred for 15-30 minutes to form a liquid.

[0018] S2: The feed liquid enters the filter press and is filtered. The operating pressure is 0.05-0.3MPa. The insoluble by-products filtered out by the filter press are fed into the slag pool. The clean feed liquid filtered out by the filter press is fed into the air-cooling tower.

[0019] S2-1: The processing chamber in the filter press is cooked through a cooking system. The resulting slag liquid is fed into a slag tank. The slag liquid in the slag tank is filtered through a filter frame to form a feed liquid. The feed liquid is fed into a mother liquor tank for circulation and purification.

[0020] S3: The liquid feed is cooled to 55-65℃ in the air-cooling tower, and crystals precipitate at the bottom of the air-cooling tower;

[0021] S4: The material containing the precipitated crystals is fed into a centrifuge for separation. The centrifuge rotates at 1000-1200 rpm. The separated wet material is fed into a dryer for drying. The dried material is then fed into a separator for separation and dust removal.

[0022] S4-1: The mother liquor separated by the centrifuge is fed into the mother liquor tank and then into the dissolving tank for circulation and purification;

[0023] S5: The dust gas after being processed by the separator is removed by the dust collector. The gas after dust removal is discharged through the exhaust pipe. The dry material after being processed by the separator is fed into the silo for storage, completing the cycle purification operation.

[0024] As a preferred embodiment of the melamine recycling purification and refining production process provided by the present invention, step S1 further includes: the dissolving tank is divided into tank body one, tank body two and tank body three arranged in series. The raw material first enters tank body one for mixing and stirring. Activated carbon is added in appropriate amount according to the color of the mother liquor for color adjustment. The color-adjusted raw material passes through tank body one, tank body two and tank body three in sequence by overflow to form a feed liquid.

[0025] Step S2-1 also includes: at the end of each shift, the processing chamber in the filter press is steamed through the steaming system, and saturated steam of 0.3-0.5MPa is input into the filter press for 13-17 minutes.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. This invention provides a melamine recycling purification and refining production device and process. During centrifugation, a mother liquor is generated. This mother liquor is transported through pipelines to a mother liquor tank for collection. After testing, the liquid in the mother liquor tank is circulated through pipelines to a dissolving tank and then enters the dissolving process. It is then re-input into the dissolving tank through pipelines, forming a mother liquor recycling path for recycling purification. A cooking system is used to cook the used filter press. At the end of each shift, the processing chamber in the filter press is cooked through the cooking system. The resulting residue is input into a residue tank. The residue in the residue tank is filtered through a filter frame to form a liquid, which is input into the mother liquor tank for recycling purification. The residue is then input into the dissolving tank, forming a cooking liquor recovery path. This process recycles and purifies the residual melamine residue on the filter press, making the entire melamine recycling purification continuous: continuous mother liquor input, continuous feeding, and continuous delivery of liquid to the filter press, improving raw material utilization and purification rate.

[0028] 2. The present invention provides a melamine recycling purification and refining production device and process. When filtering melamine dust through a bag filter, the amount of melamine dust adhering to the outside of the bag is detected by the deformation of the lower support frame at the bottom of the bag and the upper support frame at the top. When the amount of dust is large, the dust bag is wrapped by controlling the external baffle plate of the bag and cleaning the dust on the bag. The cleaned melamine dust falls to the bottom for collection, realizing the non-stop recycling purification of melamine and improving the purification efficiency. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 The production process flow diagram provided for this invention;

[0031] Figure 2 This is a schematic diagram of the installation of the separator and dust collector provided by the present invention;

[0032] Figure 3 This is a schematic diagram showing the installation position of the bag mechanism and partition provided by the present invention;

[0033] Figure 4 This is a schematic diagram of the structure of the barrier plate provided by the present invention when it seals the dust collection bag;

[0034] Figure 5 This is a diagram showing the control status of the barrier plate on the outer ring of the dust collector bag provided by the present invention.

[0035] Figure 6 A schematic diagram showing the positions of the dust collection bag, the lower support frame, and the upper support frame provided by the present invention;

[0036] Figure 7 This is a schematic diagram of the lower support frame during deformation, provided by the present invention.

[0037] Figure 8 This is a structural diagram of the upper and lower support frames when they deform, as provided by the present invention.

[0038] The markings in the diagram are explained as follows:

[0039] 1. Dissolving tank; 2. Solvent aid; 3. Filter press; 4. Air-cooled tower; 5. Centrifuge; 6. Mother liquor tank; 7. Slag tank; 8. Inlet; 9. Dryer; 10. Separator; 11. Heater; 12. Crusher; 13. Silo; 14. Dust collector; 15. Exhaust stack; 16. Steam pipe; 17. Dust removal chamber; 18. Input pipe; 19. Output pipe; 20. Discharge pipe; 21. Pulse tank; 22. Baffle plate; 23. Dust collection bag; 24. Barrier plate; 25. Drive assembly; 26. Pulse head; 27. Solenoid valve; 28. Filter hole; 29. ​​Lower support frame; 30. Upper support frame; 31. Middle support rod; 32. Movable sleeve; 33. Connecting rod; 34. Lower proximity switch; 35. Vibration motor; 36. Upper proximity switch. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0041] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other.

[0042] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0043] Example 1

[0044] Please refer to Figure 1 This invention discloses a melamine recycling and refining production apparatus, comprising a dissolving tank 1, a mother liquor tank 6, and a slag tank 7. The input end of the dissolving tank 1 is fed with raw melamine through an inlet 8. The output end of the dissolving tank 1 is connected in series via pipes to a filter press 3, an air-cooled tower 4, a centrifuge 5, a dryer 9, and a separator 10. The dry material output end of the separator 10 is connected to a silo 13 via a pipe, and the dust output end of the separator 10 is connected to a dust collector 14 via a pipe. The gas output end of the dust collector 14 is connected to an exhaust stack 15. Melamine raw melamine is added to the dissolving tank 1, and activated carbon is added to adjust the color according to the color of the raw melamine. Preferably, an online colorimeter is used to detect the color of the raw melamine. In the dissolving tank 1, the liquid is heated to 92-96°C using steam, and after being fully dissolved by stirring, it is pumped... The liquid is fed into filter press 3, where it is filtered to produce a clean liquid. The clean liquid enters an intermediate liquid tank and is then pumped to an air-cooling tower 4. The air-cooling tower 4 cools and crystallizes the liquid. The precipitated crystals (solid-liquid mixture) settle in the air-cooling tower 4 and are discharged from the bottom of the tower to a centrifuge 5 for separation. The wet material separated by the centrifuge 5 is fed into a dryer 9 for drying. After drying, the melamine is separated by a melamine separator 10 and the separated melamine enters a silo 13. After packaging, it is stored in a warehouse. The melamine-containing dust separated by the separator 10 is removed by a dust collector 14. The clean gas after dust removal is discharged through an exhaust pipe 15, reducing environmental pollution. The dust filtered by the dust collector 14 is recycled to improve the melamine purification effect.

[0045] In addition, the mother liquor tank 6 and the slag tank 7 are arranged adjacent to each other and connected by a filter assembly. The slag tank 7 is pumped to the filter assembly and filtered before entering the mother liquor tank 6. The filter assembly is a plate and frame filter structure, which is a common filter structure in the prior art. The mother liquor output end of the centrifuge 5 is connected to the input end of the mother liquor tank 6 through a pipeline. The filter residue output end of the filter press 3 is connected to the input end of the slag tank 7 through a pipeline. The output end of the mother liquor tank 6 is connected to the input end of the dissolving tank 1 through a pipeline. When the centrifuge 5 is working, it will generate mother liquor. The mother liquor generated at this time is transported to the mother liquor tank 6 for collection through a pipeline. After the material liquid entering the mother liquor tank 6 is detected, it is circulated to the dissolving tank 1 through a pipeline and enters the dissolving process. It is then reintroduced into the dissolving tank 1 through a pipeline. In the process, a mother liquor circulation path is formed to achieve cyclic purification. The filter press 3 is connected to a cooking system, which is used to cook the processing chamber in the filter press 3. The cooking system is used to cook the filter press 3 after use. At the end of each shift, the processing chamber in the filter press 3 is cooked by the cooking system. The slag liquid formed by cooking is input into the slag pool 7. The slag liquid in the slag pool 7 is filtered through the filter frame to form the feed liquid. The feed liquid is input into the mother liquor pool 6 for cyclic purification. The mother liquor pool 6 is input into the dissolving pool 1 to form a cooking liquor recovery path. The residual melamine slag liquid on the filter press 3 is cyclically purified, so that the entire melamine cyclic purification is continuous: continuous input of mother liquor, continuous feeding, and continuous delivery of feed liquid to the filter press 3, which improves the utilization rate and purification rate of raw materials.

[0046] In this embodiment, the cooking system includes a steam pipe 16, which is connected in sequence to the mother liquor tank 6 and the dissolving tank 1. Hot steam is input into the mother liquor tank 6 through the steam pipe 16 to heat the liquid in the mother liquor tank 6 and then injected into the dissolving tank 1. The hot steam enters the dissolving tank 1 to heat the liquid in the dissolving tank 1. When it is necessary to cook the filter press 3, the hot steam enters the filter press 3 through the dissolving tank 1 to perform cooking operation on the processing chamber of the filter press 3.

[0047] In addition, a solvent aid 2 is connected in series between the dissolving tank 1 and the filter press 3. The bottom filter residue output end of the solvent aid 2 is connected to the input end of the residue tank 7. The solvent aid 2 stirs and dissolves the liquid pumped into the dissolving tank 1, and the dissolved liquid is input into the filter press 3 for filtration. The residue at the bottom of the solvent aid 2 is input into the residue tank 7 for circulation and purification. A heater 11 is installed on the dryer 9. The heater 11 is used to input hot air into the dryer 9. A pulverizer 12 is connected in series between the dry material output end of the separator 10 and the silo 13. The air is heated by the heater 11 and input into the dryer 9 to dry the wet material input into the dryer 9. The dried melamine is pulverized by the pulverizer 12 and the pulverized melamine is stored in the silo 13.

[0048] Please see Figure 1 The present invention discloses a melamine recycling purification and refining production process, comprising the following steps:

[0049] S1: The raw material is put into the dissolving tank 1 for dissolution. The dissolving tank 1 is heated with steam at 92-96℃ and stirred for 15-30 minutes to form a liquid.

[0050] S2: The feed liquid enters the filter press 3 and is filtered. The operating pressure is 0.05-0.3MPa. The insoluble byproducts filtered out by the filter press 3 are fed into the slag tank 7. The clean feed liquid filtered out by the filter press 3 is fed into the air cooling tower 4.

[0051] S2-1: The processing chamber in the filter press 3 is cooked by the cooking system. The resulting slag is fed into the slag tank 7. The slag in the slag tank 7 is filtered through the filter frame to form a feed liquid. The feed liquid is fed into the mother liquor tank 6 for circulation and purification. The waste residue in the filter press 3 is treated, and the treated slag is fed into the mother liquor tank 6 and then fed into the dissolving tank 1 for circulation and purification. This forms a cooking liquor recovery path, improves the utilization rate of raw materials, and the cooking system can simultaneously reduce the clogging of the filter press 3 and reduce maintenance costs.

[0052] S3: The liquid feed is cooled to 55-65℃ in the air-cooled tower 4, and crystals precipitate at the bottom of the air-cooled tower 4;

[0053] S4: The material water from which crystals are precipitated is fed into centrifuge 5 for separation, wherein the speed of centrifuge 5 is 1000-1200 rpm. The separated wet material is fed into dryer 9 for drying, and the dried material is fed into separator 10 for separation and dust removal.

[0054] S4-1: The mother liquor separated by centrifuge 5 is fed into mother liquor tank 6 and then into dissolving tank 1 for circulation and purification. This can form a mother liquor circulation path and improve the utilization rate of raw materials after multiple cycles.

[0055] S5: The dust gas after being processed by separator 10 is removed by dust collector 14. The gas after dust removal is discharged through exhaust pipe 15. The dry material after being processed by separator 10 is fed into silo 13 for storage, completing the cycle purification operation.

[0056] It is worth mentioning that step S1 also includes: the dissolving tank 1 is divided into tank 1, tank 2 and tank 3 arranged in series. The raw material first enters tank 1 for mixing and stirring. Activated carbon is added in appropriate amount according to the color of the mother liquor. The colored raw material passes through tank 1, tank 2 and tank 3 in sequence by overflow to form a material liquid.

[0057] Step S2-1 also includes: at the end of each shift, the processing chamber in the filter press 3 is subjected to a cooking process by a cooking system, and saturated steam of 0.3-0.5 MPa is input into the filter press 3 for a cooking time of 13-17 minutes.

[0058] This ensures that the entire melamine recycling and purification process is continuous: continuous feeding of mother liquor, continuous feeding of raw materials, and continuous delivery of feed liquid to filter press 3, thereby improving the utilization rate and purification rate of raw materials.

[0059] Example 2

[0060] The melamine recycling and refining production apparatus provided in Example 1 is further optimized. Unlike Example 1, when separating the dried melamine through separator 10, a cyclone separator is used for separation, followed by dust filtration through a bag filter. The filtered melamine dust remains on the filter bags. To treat this dust, a high-pressure gas pulse is typically used to blow the dust back, re-blowing the dust adhering to the bags back into the filter chamber. To prevent the melamine dust from re-adsorbing onto the bags, pulse cleaning is performed while the bag filter is stopped, causing the backflushed melamine dust to fall to the bottom of the dust collector 14 for collection. Therefore, the process of treating the dust on the bags requires a shutdown, affecting the efficiency of the melamine recycling and refining production. Please refer to [link to relevant documentation]. Figures 2-8 Dust collector 14 is a baghouse dust collector, which includes a dust collection chamber 17 and a bag filter mechanism installed in the dust collection chamber 17. The inlet pipe 18 of the dust collection chamber 17 is connected to the dust output end of the separator 10. The top of the dust collection chamber 17 is connected to the exhaust stack 15 through the outlet pipe 19. The bottom of the dust collection chamber 17 is provided with an outlet pipe 20. A partition 22 is provided in the middle of the inner cavity of the dust collection chamber 17, and the bag filter mechanism is installed on the partition 22. The melamine separated by the separator 10... Amine dust enters the inner cavity of the dust removal chamber 17 through the input pipe 18. The inner cavity of the dust removal chamber 17 is divided into two spaces by the partition 22. The space above the partition 22 is the filtered air, which is connected to the output pipe 19. The space below the partition 22 is the unfiltered air, which is connected to the discharge pipe 20 and the input pipe 18. The air in the dust removal chamber 17 is drawn out through the output pipe 19 by the action of the fan. The air containing melamine dust is filtered by the bag filter mechanism and adheres to the outer wall of the bag filter mechanism.

[0061] It is worth mentioning that you should refer to Figures 2-5The partition 22 has multiple filter holes 28. A pulse jet canister 21 is installed on the dust collection chamber 17. The bag filter mechanism includes dust collection bags 23 corresponding to the filter holes 28, baffle plates 24 surrounding the outer ring of the dust collection bags 23, and pulse heads 26 located above each dust collection bag 23. A solenoid valve 27 is installed on each pulse head 26. Each pulse head 26 is connected to the pulse jet canister 21. The baffle plates 24 corresponding to the dust collection bags 23 are rotatably connected to the partition 22. Drive assemblies 25 are installed at corresponding positions on the partition 22 and dust collection bags 23. The drive assemblies 25 drive the baffle plates 24 surrounding the outer ring of the dust collection bags 23 to rotate. Multiple baffle plates 24 are arranged around the outer ring of each dust collection bag 23. The baffle plates 24 are in an unfolded state as shown in the image. Figure 3 and Figure 5 As shown on the left, at this time, the outside air comes into contact with the dust collection bag 23 and is filtered by the dust collection bag 23. When the drive assembly 25 drives the corresponding baffle plate 24 on the dust collection bag 23 to rotate, the multiple baffle plates 24 rotate to wrap around the dust collection bag 23, as shown on the left. Figure 4 and Figure 5 As shown on the right, the airflow inside the dust removal chamber 17 does not interact with the dust removal bag 23. In this state, when the middle of the dust removal bag 23 is impacted by a high-pressure gas pulse, the melamine dust located outside the dust removal bag 23 will be shaken off. Since the outside of the dust removal bag 23 is sealed by the baffle plate 24, the shaken-off melamine dust will fall to the discharge pipe 20 by gravity and be discharged through the discharge pipe 20. Therefore, pulse dust removal can be performed on the clogged dust removal bag 23 without stopping the bag dust collector, thereby improving the efficiency of melamine circulation and purification.

[0062] In addition, the pulse tank 21 stores high-pressure gas, which is sprayed out through the corresponding pulse head 26 to perform pulse cleaning on the corresponding dust bag 23. Each pulse head 26 is controlled to work independently by the control solenoid valve 27, and can process the corresponding dust bag 23 individually. When driving the baffle plate 24 on the outer ring of the dust bag 23, the drive assembly 25 controls multiple baffle plates 24 to rotate simultaneously, thereby controlling the deflection of the baffle plates 24 to determine whether the dust bag 23 is wrapped. The drive assembly 25 is a common drive mechanism in the prior art, which can drive multiple baffle plates 24 to rotate in the same direction at the same time, and is a prior art well known to those skilled in the art.

[0063] In this embodiment, please refer to Figures 6-8Each dust bag 23 has a lower support frame 29 and an upper support frame 30 stacked from bottom to top inside. A middle support rod 31 is vertically arranged in the middle of the dust bag 23. A movable sleeve 32 is provided at the corresponding position of the middle support rod 31 and the lower support frame 29 and the upper support frame 30. A connecting rod 33 is rotatably connected to the outer wall of the movable sleeve 32. The end of the connecting rod 33 away from the movable sleeve 32 is rotatably connected to the corresponding lower support frame 29 or upper support frame 30. By setting the lower support frame 29 and the upper support frame 30, which are elastic structures, the dust bag 23 is elastically supported, ensuring that the dust bag 23 is in an open state, thereby improving the dust filtration effect of the dust bag 23. When the outer wall of the lower support frame 29 and the upper support frame 30 is subjected to force, it is concave inward and pushes the connecting rod 33. The connecting rod 33 pushes the movable sleeve 32 at its end to move along the middle support rod 31.

[0064] In addition, to enable individual detection of the filtration status of each dust bag 23, a lower proximity switch 34 and a vibration motor 35 are respectively installed on one side of the movable sleeve 32 corresponding to the lower support frame 29. The lower proximity switch 34 and the vibration motor 35 are installed with the middle support rod 31. An upper proximity switch 36 is installed on one side of the movable sleeve 32 corresponding to the upper support frame 30. The upper proximity switch 36 is installed with the middle support rod 31. As the amount of melamine dust adhering to the outside of the dust bag 23 gradually increases, the inward concavity of the upper support frame 30 and the lower support frame 29 will drive the corresponding connecting rod 33 and movable sleeve 32 to move. The movable sleeve 32 will contact the corresponding lower proximity switch 34 or upper proximity switch 36. In addition, a main control unit is installed on the bag filter. The main control unit is divided into The main control unit is electrically connected to the solenoid valve 27, lower proximity switch 34, vibration motor 35, and upper proximity switch 36. The main control unit receives the detection signals from the lower proximity switch 34 and the upper proximity switch 36 to determine the amount of melamine dust at the corresponding location of the dust bag 23 and the lower support frame 29 or upper support frame 30, and determines whether there is a blockage at the corresponding location. If it is determined that the dust bag 23 needs to be cleaned, the main control unit controls the vibration motor 35 to work. The vibration motor 35 vibrates to remove the dust on the outside of the dust bag 23. The main control unit controls the solenoid valve 27 on the corresponding pulse head 26 to open, and performs pulse cleaning of the dust bag 23 with high-pressure gas. During this process, the baffle plate 24 is in a closed state on the outer ring of the dust bag 23.

[0065] Furthermore, since melamine-containing dust enters through the lower part of the dust collection chamber 17, the amount of dust accumulated at the bottom of the dust collection bag 23 is usually greater than that at the top. The dust volume at the top and bottom of the dust collection bag 23 is uneven. Since the pulse head 26 is located above the dust collection bag 23, close to its upper part, the pulses emitted by it have a better cleaning effect on the upper part of the dust collection bag 23, but a weaker cleaning effect on the lower part. Therefore, when the dust volume at the bottom of the dust collection bag 23 is greater, if... Figure 7As shown, the concave drive sleeve 32 of the lower support frame 29 moves upward and contacts the lower proximity switch 34. At this time, the main control unit controls the vibration motor 35 to work. The vibration motor 35 drives the lower support frame 29 to vibrate, shaking off the dust from the lower part of the dust bag 23, thus cleaning the dust in the lower part of the dust bag 23. When there is a lot of dust in the upper part of the dust bag 23, some dust will also accumulate in the lower part of the dust bag 23, such as... Figure 8 As shown, at this time, the upper support frame 30 is recessed and the movable sleeve 32 moves upward to contact the upper proximity switch 36. At this time, the main control unit controls the solenoid valve 27 at the corresponding pulse head 26 to open, and high-pressure gas is used to perform pulse cleaning on the dust bag 23 to remove the melamine dust from the upper and lower parts of the dust bag 23, so as to achieve effective cleaning of both the upper and lower parts of the dust bag 23, and to achieve cleaning without stopping the machine, thereby improving the efficiency of melamine circulation and purification.

Claims

1. A melamine recycling purification and refining production device, characterized in that, include: The dissolving tank (1) is connected to the input end of the dissolving tank (1) through the inlet (8) for the raw liquid. The output end of the dissolving tank (1) is connected in series with the filter press (3), the air-cooled tower (4), the centrifuge (5), the dryer (9) and the separator (10) through the pipeline. The dry material output end of the separator (10) is connected to the silo (13) through the pipeline. The dust output end of the separator (10) is connected to the dust collector (14) through the pipeline. The gas output end of the dust collector (14) is connected to the exhaust stack (15). The mother liquor tank (6) and the slag tank (7) are arranged adjacent to each other. The mother liquor tank (6) and the slag tank (7) are connected through a filter assembly. The mother liquor output end of the centrifuge (5) is connected to the input end of the mother liquor tank (6) through a pipe. The filter residue output end of the filter press (3) is connected to the input end of the slag tank (7) through a pipe. The output end of the mother liquor tank (6) is connected to the input end of the dissolving tank (1) through a pipe. The filter press (3) is connected to a cooking system, which is used to cook the processing chamber in the filter press (3).

2. The melamine recycling purification and refining production apparatus according to claim 1, characterized in that, The cooking system includes a steam pipe (16), which is connected in sequence to the mother liquor tank (6) and the dissolving tank (1).

3. The melamine recycling purification and refining production apparatus according to claim 1, characterized in that, A solvent aid (2) is connected in series between the dissolving tank (1) and the filter press (3), and the bottom filter residue output end of the solvent aid (2) is connected to the input end of the residue tank (7).

4. The melamine recycling purification and refining production apparatus according to claim 1, characterized in that, A heater (11) is installed on the dryer (9) and the heater (11) is used to input hot air into the dryer (9). A crusher (12) is connected in series between the dry material output end of the separator (10) and the hopper (13).

5. The melamine recycling purification and refining production apparatus according to claim 1, characterized in that, The dust collector (14) is a bag filter dust collector, which includes a dust collection chamber (17) and a bag filter mechanism installed in the dust collection chamber (17). The input pipe (18) of the dust collection chamber (17) is connected to the dust output end of the separator (10). The top of the dust collection chamber (17) is connected to the exhaust pipe (15) through the output pipe (19). The bottom of the dust collection chamber (17) is provided with a discharge pipe (20). A partition (22) is provided in the middle of the inner cavity of the dust collection chamber (17). The bag filter mechanism is installed on the partition (22).

6. The melamine recycling purification and refining production apparatus according to claim 5, characterized in that, The partition (22) has multiple filter holes (28), the dust removal chamber (17) is equipped with a pulse tank (21), the bag mechanism includes a dust removal bag (23) corresponding to the filter holes (28), a baffle plate (24) surrounding the outer ring of the dust removal bag (23), and a pulse head (26) located above each dust removal bag (23). A solenoid valve (27) is installed on the pulse head (26), and each pulse head (26) is connected to the pulse tank (21). The baffle plate (24) corresponding to the dust removal bag (23) is rotatably connected to the partition (22). A drive assembly (25) is installed at the corresponding position of the partition (22) and the dust removal bag (23). The drive assembly (25) is used to drive the baffle plate (24) surrounding the outer ring of the dust removal bag (23) to rotate.

7. The melamine recycling purification and refining production apparatus according to claim 6, characterized in that, Each dust bag (23) is provided with a lower support frame (29) and an upper support frame (30) stacked from bottom to top inside. A middle support rod (31) is vertically arranged in the middle of the dust bag (23). A movable sleeve (32) is provided at the corresponding position of the middle support rod (31) and the lower support frame (29) and the upper support frame (30). A connecting rod (33) is rotatably connected to the outer wall of the movable sleeve (32). The end of the connecting rod (33) away from the movable sleeve (32) is rotatably connected to the corresponding lower support frame (29) or upper support frame (30).

8. A melamine recycling purification and refining production apparatus according to claim 7, characterized in that, A lower proximity switch (34) and a vibration motor (35) are respectively provided on one side of the movable sleeve (32) corresponding to the lower support frame (29), and the lower proximity switch (34) and the vibration motor (35) are installed with the middle support rod (31); an upper proximity switch (36) is provided on one side of the movable sleeve (32) corresponding to the upper support frame (30), and the upper proximity switch (36) is installed with the middle support rod (31).

9. A melamine recycling purification and refining production process, characterized in that, The melamine recycling and refining production apparatus according to any one of claims 1-8 includes the following steps: S1: The raw material is put into the dissolving tank (1) for dissolution. The dissolving tank (1) is heated and stirred with steam at 92-96℃ for 15-30 minutes to form a liquid. S2: The liquid enters the filter press (3) and is filtered. The operating pressure is 0.05-0.3MPa. The insoluble byproducts are filtered out by the filter press (3) and fed into the slag tank (7). The clean liquid is filtered out by the filter press (3) and fed into the air-cooled tower (4). S2-1: The processing chamber in the filter press (3) is cooked by the cooking system. The slag liquid formed by cooking is fed into the slag tank (7). The slag liquid in the slag tank (7) is filtered by the filter frame to form the feed liquid. The feed liquid is fed into the mother liquor tank (6) for circulation and purification. S3: The liquid feed is cooled to 55-65℃ in the air-cooled tower (4) and crystals precipitate at the bottom of the air-cooled tower (4); S4: The material water from which crystals are precipitated is fed into a centrifuge (5) for separation, wherein the speed of the centrifuge (5) is 1000-1200 rpm, the separated wet material is fed into a dryer (9) for drying, and the dried material is fed into a separator (10) for separation and dust removal. S4-1: The mother liquor separated by the centrifuge (5) is fed into the mother liquor tank (6) and then into the dissolving tank (1) for circulation and purification; S5: The dust gas after being processed by the separator (10) is removed by the dust collector (14), and the gas after being removed by the dust collector is discharged through the exhaust pipe (15). The dry material after being processed by the separator (10) is fed into the silo (13) for storage, thus completing the cycle purification operation.

10. The melamine recycling purification and refining production process according to claim 9, characterized in that, Step S1 also includes: the dissolving tank (1) is divided into tank body one, tank body two and tank body three arranged in series. The raw material first enters tank body one for mixing and stirring. Activated carbon is added in appropriate amount according to the color of the mother liquor. The raw material after color adjustment passes through tank body one, tank body two and tank body three in sequence by overflow to form a material liquid. Step S2-1 also includes: at the end of each shift, the processing chamber in the filter press (3) is steamed through the steaming system, and saturated steam of 0.3-0.5MPa is input into the filter press (3) for 13-17 minutes.

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