Crystallization filter device for chemical product processing

Abstract

The application provides a crystallization filter device for chemical product processing, and belongs to the technical field of chemical product production. The device comprises a rack, a mother liquor tank arranged in the rack, a rotary drum rotatably connected to the inside of the mother liquor tank, filter cloth arranged on the surface of the rotary drum, filter chambers evenly arranged in the circumferential direction of the inside of the rotary drum, a first negative pressure pipe and a second negative pressure pipe arranged in each filter chamber, a support cylinder arranged at the upper end of the rack, the front end of the rotary drum rotatably connected to the support cylinder, a distribution ring rotatably connected to the inside of the support cylinder, and a liquid discharge assembly arranged in the inside of each filter chamber and matched with the distribution ring. The device can retain part of liquid in the filter chambers, and the liquid flow during liquid discharge can fully wrap and discharge the crystal particles on the filter chamber wall surface and in the corners into the support cylinder, thereby reducing the risk of blockage in the filter chambers and the number of cleaning stops.

Description

Technical Field

[0001] This application relates to the field of chemical product manufacturing technology, specifically to a crystallization filtration device for chemical product processing. Background Technology

[0002] In the industrial-scale preparation of chlorophthalic anhydride and its derivatives, filtration after crystallization is a critical purification step; considering the characteristics of these compounds as well as the scale, efficiency and cost of industrial production, rotary drum vacuum filters are usually used as the main equipment for crystallization filtration.

[0003] When the rotary drum vacuum filter is in use, the mother liquor is sent into the mother liquor tank through a pipeline. Inside the mother liquor tank, there is a horizontally set rotary drum. The bottom part of the drum is immersed in the mother liquor tank. The drum wall has openings, and the drum surface is covered with a support plate and filter cloth to form a filter surface. The space under the filter surface is divided into several separated fan-shaped filter chambers. Each filter chamber is connected to a distribution valve by a conduit. Every time the drum rotates once, each filter chamber is connected to the vacuum system and the compressed air system in turn through the distribution valve, and the operations of filtration, washing, drying, unloading and regeneration of filter media (filter cloth) are completed in sequence.

[0004] Referring to Chinese patent document CN119075450B, entitled "A Filtering Device for Lithium Carbonate Production," the device includes a drum body. The drum body has two cavities: a first cavity and a second cavity. A support plate, a partition plate, and a vertical plate are arranged sequentially on the drum body. The partition plate divides the first cavity into a left negative pressure chamber and a right positive pressure chamber. Multiple negative pressure pipes are arranged on the inner wall of the negative pressure chamber. The support plate has negative pressure pipes and air blowing pipes connected to the negative pressure chamber. A sealing plate and an overflow plate are arranged between the support plate and the partition plate. The sealing plate connects the air blowing pipe to a negative pressure pipe. A feed pipe is arranged on the partition plate. A linear output component and connected feed plates one and two are arranged on the support plate. Multiple positive pressure pipes are arranged on the inner wall of the positive pressure chamber. A positive pressure pipe is rotatably connected to the inner wall of the second cavity. This technology allows for non-stop cleaning of solid deposits inside the drum body, which helps improve the filtration effect.

[0005] Referring to the above technical solution, when the rotary drum vacuum filter is applied to the filtration and separation of chlorophthalic anhydride and its derivatives, the equipment is prone to problems such as filter cloth clogging, difficulty in filter cake formation, or easy detachment after formation due to the characteristics of the target product and process conditions, which seriously restricts the filtration efficiency. Specifically, during the process of using the vacuum system to draw up the mother liquor, the mother liquor may continue to precipitate crystals after entering the drum due to pressure. The mother liquor in the drum will gradually be discharged as the drum rotates. However, since the rotation speed of the drum is usually slow, some of the crystals precipitated in the drum cannot be discharged in time. These crystals will remain in the drum and accumulate over time, which can easily lead to clogging of the filter chamber inside the drum. Currently, to address this problem, it is necessary to stop the machine to clean the inside of the rotary drum vacuum filter, which will undoubtedly interrupt the continuous production process and significantly reduce production efficiency. Summary of the Invention

[0006] In view of this, this application provides a crystallization filtration device for chemical product processing, which is used to solve the problem of clogging of the filter chamber inside the drum due to incomplete crystal discharge.

[0007] To solve the above-mentioned technical problems, this application provides a crystallization filtration device for chemical product processing, including a frame and a mother liquor tank set inside the frame. A rotating drum is rotatably connected inside the mother liquor tank. The surface of the rotating drum is covered with filter cloth. Filter chambers are evenly distributed in the circumferential direction inside the rotating drum. Each filter chamber is provided with a first negative pressure pipe and a second negative pressure pipe. The second negative pressure pipe is longer than the first negative pressure pipe, and the end of the second negative pressure pipe is located close to the filter cloth. A support cylinder is set at the upper end of the frame. The front end of the rotating drum is rotatably connected to the support cylinder. A distribution ring is set inside the support cylinder and is rotatably connected to the rotating drum. An air extraction hole is set inside the distribution ring and communicates with the inside of the support cylinder. A first arc-shaped groove at the bottom of the air extraction hole can communicate with the first negative pressure pipe, and a second arc-shaped groove on the rear side of the air extraction hole can communicate with the second negative pressure pipe. Each filter chamber is provided with a liquid drainage component that cooperates with the distribution ring.

[0008] By adopting the above technical solution, the first negative pressure pipe and the second negative pressure pipe work alternately. When the first negative pressure pipe stops pumping air, the second negative pressure pipe opens. At this time, because the end of the second negative pressure pipe is close to the filter cloth and is at the upper end of the liquid level in the filter chamber, the mother liquor in the filter chamber can be prevented from being drawn out by the second negative pressure pipe. Thus, even after the filter chamber leaves the mother liquor tank, it can still maintain a negative pressure state in the filter chamber and retain some liquid in the filter chamber. The continuous negative pressure can prevent the filter cake layer from becoming loose due to changes in external pressure. The retained liquid can prevent crystals from adhering to the inside of the filter chamber. When the filter chamber rotates to the top with the drum, the liquid remaining in the filter chamber can be quickly discharged through the drainage component. Because the liquid has fluidity and entrainment ability, it can fully entrain crystal particles in areas that are prone to residue, such as the filter chamber wall and corners, and quickly discharge them into the support cylinder. This drainage method eliminates the basis for crystal adhesion inside the filter chamber through the flushing action of the liquid, reduces the residue of crystals in the filter chamber from the root, reduces the risk of blockage inside the filter chamber, extends the operating cycle of the equipment, and reduces the number of shutdowns for cleaning.

[0009] Optionally, the drainage assembly includes drainage channels disposed inside the drum, each drainage channel communicating with the interior of the corresponding filter chamber. Each drum is slidably connected with a T-shaped rod capable of sealing the drainage channels. The drainage channels distributed in a circumferential array can communicate with the interior of the support cylinder through drainage holes inside the distribution ring.

[0010] By adopting the above technical solution, the drainage channel provides a channel for the liquid to be discharged from the filter chamber. The T-shaped rod can dynamically seal and open the drainage channel during the rotation of the drum. When the drainage channel is connected to the drainage hole of the distribution ring, the T-shaped rod releases the seal, and the liquid in the filter chamber can quickly enter the support cylinder for discharge through the drainage channel and drainage hole. When not connected, the T-shaped rod seals the drainage channel to ensure the sealing of the filter chamber during the negative pressure adsorption stage, ensure the negative pressure adsorption effect, and realize the orderly control of the liquid discharge from the filter chamber.

[0011] Optionally, the distribution ring has a drive sleeve in the middle, and the outer side of the drive sleeve is axially arrayed with protrusions that can abut against the end of the T-shaped rod.

[0012] By adopting the above technical solution, when the drum rotates, the drive sleeve remains stationary. When the T-shaped rod rotates to abut against the protrusion on the outer side of the drive sleeve, it can move towards the filter chamber, release the seal on the drainage channel, and allow the liquid in the filter chamber to be discharged. The rotation of the drum is used to realize the automatic control of the T-shaped rod, and the opening and closing of the T-shaped rod is more precise.

[0013] Optionally, each of the T-shaped rods is provided with a limit ring at the end near the center of the drum, and a spring is fitted at the end of each T-shaped rod to contact the limit ring, in order to maintain the seal between the T-shaped rod and the drainage channel.

[0014] By adopting the above technical solution, the limiting ring restricts the sliding stroke of the T-shaped rod to prevent it from moving excessively. The spring applies continuous elastic force to the limiting ring, which can always keep the T-shaped rod in close contact with the drainage channel, ensuring the sealing reliability of the drainage channel in the non-drainage state, preventing mother liquor leakage during negative pressure adsorption, ensuring negative pressure efficiency, and quickly resetting after the protrusion detaches from the T-shaped rod.

[0015] Optionally, a circulation pump is provided at the drain outlet at the lower end of the outer side of the support cylinder, and the outlet of the circulation pump is connected to the inside of the mother liquor tank.

[0016] By adopting the above technical solution, the circulating pump can draw the mother liquor collected in the support cylinder back to the mother liquor tank through the drain outlet, thereby realizing the circulation and filtration of the mother liquor, and making the filtration of the mother liquor more thorough.

[0017] Optionally, the side of the filter chamber closest to the center of the drum is inclined from front to back.

[0018] By adopting the above technical solution, the inclined setting inside the filter chamber can utilize gravity to cause the crystals and residual mother liquor in the filter chamber to converge and flow towards the drain channel, which facilitates the rapid discharge of liquid remaining in the filter chamber, reduces the probability of liquid accumulation and crystal residue in the filter chamber, and lowers the risk of filter chamber blockage.

[0019] Optionally, the outer openings of the drainage channels are all inverted conical in shape, and the openings of the drainage channels are all provided with sealing rings that can abut against the T-shaped rods.

[0020] By adopting the above technical solution, the inverted conical opening design increases the communication area between the drainage channel and the filter chamber, which facilitates the rapid entry of crystals and liquids into the drainage channel, reduces discharge resistance, and the sealing ring enhances the sealing performance between the T-shaped rod and the drainage channel, preventing the mother liquor from leaking from the gaps during negative pressure adsorption, ensuring that the negative pressure effectively acts on the surface of the filter cloth, and improving the filtration effect.

[0021] Optionally, the distribution ring is provided with an air blowing hole that can communicate with the drainage channel. The outer opening of the air blowing hole can communicate with the first negative pressure pipe and the second negative pressure pipe. The air blowing hole is connected to an external blower through a pipe.

[0022] By adopting the above technical solution, after the negative pressure adsorption is completed, the air blowing hole can be used to introduce airflow into the filter chamber through an external blower. The airflow can sweep the filter cloth and the inside of the filter chamber, resulting in a larger blowing area and more uniform blowing, thus achieving a better separation effect for the filter cake.

[0023] Optionally, the mother liquor tank is internally hinged with a swing frame, the upper end of which is hinged with a connecting rod, and the lower ends of the two connecting rods are hinged to the crankshaft end that is rotatably connected to the bottom of the frame. The bottom of the frame is equipped with a motor that can drive the crankshaft to rotate.

[0024] By adopting the above technical solution, the motor drives the crankshaft to rotate, which in turn drives the swing frame to swing back and forth in the mother liquor tank via the connecting rod. The swing of the swing frame can stir the mother liquor in the mother liquor tank, prevent the crystals in the mother liquor from settling prematurely, keep the crystals in the mother liquor in a suspended state, ensure that the filter cloth can evenly adsorb crystals when the drum rotates, improve the filtration uniformity, and avoid filter cloth blockage caused by local crystal accumulation.

[0025] Optionally, a scraper is provided at the front end of the frame, and the upper edge of the scraper can contact the filter cloth on the surface of the drum in a tangential direction.

[0026] By adopting the above technical solution, the scraper contacts the filter cloth in a tangential direction, which can scrape off the crystals attached to the surface of the filter cloth during the rotation of the drum, making it easier to collect the crystals later.

[0027] In summary, compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0028] 1. This device uses two negative pressure pipes working alternately to maintain a negative pressure state in the filter chamber while allowing some liquid to remain inside. This facilitates subsequent flushing and cleaning of the filter chamber with liquid. When the filter chamber rotates to the top, the residual liquid inside the filter chamber forms a directional flow under the negative pressure, fully entraining crystal particles on the filter chamber walls and corners and discharging them into the support cylinder. This drainage method utilizes the flushing effect of the liquid to reduce the residue of crystals in the filter chamber from the source, reducing the risk of blockage inside the filter chamber, extending the equipment's operating cycle, and reducing the number of shutdowns for cleaning. At the same time, the circulating pump circulates the liquid in the support cylinder to the mother liquor tank for further filtration, resulting in a more thorough filtration effect for the mother liquor.

[0029] 2. Air is blown into the filter chamber through the air holes inside the distribution ring when the filter chamber rotates to a specific position, causing the filter cake to separate from the filter cloth under positive pressure. Air can be blown simultaneously through the drainage channel and two negative pressure pipes, resulting in a larger blowing area and more uniform air blowing, which improves the separation effect of the filter cake. Subsequently, the scraper contacts the filter cloth on the surface of the drum in a tangential direction and scrapes off the filter cake. This can efficiently and thoroughly remove the filter cake from the surface of the filter cloth, reduce filter cake residue, and improve filtration efficiency and filter cloth service life.

[0030] 3. The swing frame installed in the mother liquor tank is connected to the crankshaft via a connecting rod. When the motor drives the crankshaft to rotate, the swing frame swings back and forth in the mother liquor tank, which can effectively prevent the precipitation of crystals in the mother liquor tank, ensure the uniformity of the mother liquor, and thus improve the filtration effect and product quality stability. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the crystallization filtration device for chemical product processing in this application;

[0032] Figure 2 This is a schematic diagram of the rear structure of this application;

[0033] Figure 3 This is a schematic diagram of the internal cross-sectional structure of this application;

[0034] Figure 4 For this application Figure 3 A magnified structural diagram at point A;

[0035] Figure 5 This is a schematic diagram of the side sectional structure of this application;

[0036] Figure 6 This is a partial structural diagram of the allocation ring in this application;

[0037] Figure 7 This is a schematic diagram of the rear structure of the allocation ring in this application;

[0038] Figure 8 For this application Figure 7 Schematic diagram of the cross-sectional structure at point AA;

[0039] Figure 9 For this application Figure 7 Schematic diagram of the cross-sectional structure at point BB.

[0040] Explanation of reference numerals in the attached drawings: 1. Frame; 101. Mother liquor tank; 102. Scraper; 2. Rotary drum; 21. Filter cloth; 22. Filter chamber; 221. First negative pressure pipe; 222. Second negative pressure pipe; 3. Support cylinder; 4. Distribution ring; 41. Air extraction port; 411. First arc-shaped groove; 412. Second arc-shaped groove; 42. Drive sleeve; 421. Protrusion; 43. Drainage hole; 44. Air blowing hole; 5. Drainage assembly; 51. Drainage channel; 511. Sealing ring; 52. T-shaped rod; 521. Limiting ring; 522. Spring; 6. Circulation pump; 7. Swing frame; 8. Connecting rod; 9. Crankshaft. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will be combined with the embodiments of this application. Figures 1-9 The technical solutions of the embodiments of this application are clearly and completely described herein. All other embodiments obtained by those skilled in the art based on the described embodiments are within the scope of protection of this application.

[0042] Reference Figure 1 , Figure 2 and Figure 3 This embodiment provides a crystallization filtration device for chemical product processing, including a frame 1, a filtration mechanism, and a drainage assembly 5. The frame 1 has a mother liquor tank 101 inside, and an inlet pipe is provided on the outside of the mother liquor tank 101, through which the mother liquor to be filtered can be sent into the mother liquor tank 101; an overflow pipe is provided on the outside of the mother liquor tank 101 to maintain the stability of the liquid level in the mother liquor tank 101.

[0043] Reference Figure 2 , Figure 5 , Figure 6 and Figure 7The filtration mechanism includes a rotating drum 2, a first negative pressure pipe 221, a second negative pressure pipe 222, a support cylinder 3, and a distribution ring 4. The rotating drum 2 is rotatably connected to the inside of the mother liquor tank 101 via a drive shaft at its center. The surface of the rotating drum 2 is provided with a filter cloth 21, and filter chambers 22 are distributed in a circular array inside the rotating drum 2. The first negative pressure pipe 221 and the second negative pressure pipe 222 are both located inside the filter chambers 22. The support cylinder 3 is located on the upper left side of the frame 1. The upper side of the outer surface of the support cylinder 3 is provided with a flange pipe that can communicate with an external negative pressure mechanism. The distribution ring 4 is located inside the support cylinder 3. The right end of the distribution ring 4 is rotatably connected to the rotating drum 2. The bottom of the distribution ring 4 is provided with an air extraction hole 41 that communicates with the inside of the support cylinder 3. The first arc-shaped groove 411 at the bottom of the air extraction hole 41 can communicate with the first negative pressure pipe 221, and the second arc-shaped groove 412 on the rear side of the air extraction hole 41 can communicate with the second negative pressure pipe 222.

[0044] In use, the mother liquor to be filtered can be sent into the mother liquor tank 101 through the inlet pipe. At the same time, the external negative pressure mechanism is connected to the air extraction pipe at the upper end of the support cylinder 3. At this time, the first negative pressure pipe 221 in the filter chamber 22 at the bottom of the drum 2 is precisely connected to the first arc-shaped groove 411 on the outside of the air extraction hole 41. The arc of the first arc-shaped groove 411 is adapted to the rotation trajectory of the drum 2, so that the negative pressure channel can always be kept unobstructed during the stage when the filter chamber 22 is immersed in the mother liquor tank 101. When the bottom of the drum 2 is immersed in the mother liquor tank 101, under the action of negative pressure, the mother liquor passes smoothly through the filter cloth 21 and enters the filter chamber 22. At this time, the filter cloth 21 traps the crystals contained in the mother liquor on the surface of the filter cloth 21, forming an initial filter cake layer on the outside of the filter cloth 21, realizing the initial separation of crystals and mother liquor. As the drum 2 rotates clockwise, the filter chamber 22 gradually rotates out. In the mother liquor tank 101, the first negative pressure pipe 221 is misaligned with the first arc-shaped groove 411 outside the air extraction hole 41, and the first negative pressure pipe 221 automatically closes. At the same time, the second negative pressure pipe 222 accurately corresponds to and connects with the second arc-shaped groove 412 behind the air extraction hole 41. This structural design realizes the alternating operation of the first negative pressure pipe 221 and the second negative pressure pipe 222. Since the end of the second negative pressure pipe 222 is close to the filter cloth 21 and is at the upper end of the liquid level in the filter chamber 22, this layout can maintain the negative pressure state in the filter chamber 22 after the filter chamber 22 leaves the mother liquor environment, and retain some liquid in the filter chamber 22. The continuous negative pressure can prevent the filter cake layer from becoming loose due to changes in external pressure. On the other hand, the retained liquid can prevent crystals from adhering to the inside of the filter chamber 22.

[0045] Reference Figure 3 , Figure 4 , Figure 5 and Figure 6The drainage assembly 5 includes drainage channels 51 and T-shaped rods 52. The drainage channels 51 are arranged in a circumferential array inside the drum 2, near the center. The T-shaped rods 52 are slidably connected inside the drum 2, located within the corresponding drainage channels 51 and capable of sealing them. The outer openings of the drainage channels 51 are all inverted conical in shape, and each opening of the drainage channel 51 is provided with a sealing ring 511 that abuts against the T-shaped rod 52. A limit ring 521 is provided at the end of the T-shaped rod 52 near the center of the drum 2. Springs 522 that contact the limiting ring 521 are fitted at the ends to maintain the seal between the T-shaped rod 52 and the drainage channel 51. A drive sleeve 42 is provided in the middle of the distribution ring 4. The outer side of the drive sleeve 42 is axially arrayed with protrusions 421 that can abut against the end of the T-shaped rod 52. A circulation pump 6 is provided at the drain port at the lower end of the outer side of the support cylinder 3. The outlet of the circulation pump 6 is connected to the inside of the mother liquor tank 101. The side of the filter chamber 22 near the center of the drum 2 is inclined from front to back so that the residual liquid in the filter chamber 22 can be completely discharged.

[0046] When the filter chamber 22 containing residual liquid rotates to its uppermost position, both the first negative pressure pipe 221 and the second negative pressure pipe 222 are misaligned with the air extraction port 41, causing the first negative pressure pipe 221 and the second negative pressure pipe 222 to close. At the same time, as the drum 2 rotates, the end of the T-shaped rod 52 at the uppermost end of the drum 2 forms a rigid abutment with the outer protrusion 421 of the drive sleeve 42, and then pushes outward along the axial direction. During this process, the limiting ring 521, through its limiting cooperation with the shoulder of the T-shaped rod 52, not only strictly limits the maximum ejection stroke of the T-shaped rod 52, but also ensures that the T-shaped rod 52 moves linearly along the axial direction through radial constraint, effectively avoiding jamming or misalignment of the sealing surface caused by swaying during the ejection process. During the ejection process, the spring 522 is gradually compressed. Its elastic deformation provides a buffer for the T-shaped rod 52, reducing the instantaneous impact force between the protrusion 421 and the end of the T-shaped rod 52, thus reducing component wear. It also stores reset potential energy, laying the foundation for subsequent sealing actions. As the T-shaped rod 52 separates from the drainage channel 51, the drainage channel 51 is fully opened. At this time, the residual liquid in the filter chamber 22 forms a directional flow under the action of concentrated negative pressure. Due to the fluidity and entrainment capacity of the liquid, it can fully entrain crystal particles in areas prone to residue, such as the walls and corners of the filter chamber 22, forming a gas-liquid-solid mixed flow state, which is quickly discharged into the support cylinder 3 along the drainage channel 51. This drainage method eliminates the basis for crystal adhesion inside the filter chamber 22 through the flushing action of the liquid, reducing the possibility of crystal residue from the root. The reduction in residue directly reduces the chance of crystal accumulation in key parts such as the filter chamber 22 channel and the filter cloth 21 pores, thereby significantly reducing the risk of blockage inside the filter chamber 22, ensuring the smooth operation of the filter chamber 22 in the long term, and reducing the cycle of subsequent shutdown and cleaning. Then, the circulation pump 6 starts and circulates the liquid in the support cylinder 3 to the mother liquor tank 101 for filtration again. Through repeated filtration, the mother liquor is deeply purified, making the filtration of the mother liquor more thorough. When the drum 2 continues to rotate, after the end of the T-shaped rod 52 disengages from the protrusion 421, the compressed spring 522 releases its elastic potential energy, pushing the T-shaped rod 52 to return to its axial position. Its sealing end re-forms a tight fit with the sealing ring 511 at the upper end of the drainage channel 51, resealing the upper end of the drainage channel 51.

[0047] Reference Figure 3 , Figure 7 , Figure 8 and Figure 9 The distribution ring 4 is provided with an air blowing hole 44 that can communicate with the drainage channel 51. The outer opening of the air blowing hole 44 can communicate with the first negative pressure pipe 221 and the second negative pressure pipe 222. The air blowing hole 44 is connected to an external blower through a pipe. The front end of the frame 1 is provided with a scraper 102. The upper edge of the scraper 102 can contact the filter cloth 21 on the surface of the drum 2 in a tangential direction.

[0048] As the drum 2 continues to rotate, when the filter chamber 22 rotates to correspond with the air blowing hole 44 on the outside of the distribution ring 4, the first negative pressure pipe 221 is connected to the air blowing hole 44. The external blower blows air into the corresponding filter chamber 22 through the pipe, the air blowing hole 44, and the first negative pressure pipe 221, causing the filter cake, which was originally tightly attached to the surface of the filter cloth 21, to gradually loosen and lift under the pressure, and tiny gaps quietly open between it and the filter cloth 21. The fine particles that were originally adsorbed on the fibers of the filter cloth 21 are also peeled off, and finally the filter cake is completely separated from the filter cloth 21. As the drum 2 continues to rotate, the scraper 102 can scrape off the filter cake on the surface of the filter cloth 21.

[0049] Reference Figure 2 and Figure 3 The mother liquor tank 101 is internally hinged with a swing frame 7. The upper end of each swing frame 7 is hinged with a connecting rod 8. The lower ends of the two connecting rods 8 are hinged to the end of the crankshaft 9, which is rotatably connected to the bottom of the frame 1. The bottom of the frame 1 is equipped with a motor that can drive the crankshaft 9 to rotate.

[0050] When in use, the motor starts, and the power output of the motor is transmitted to the crankshaft 9 through the transmission mechanism, causing the crankshaft 9 to start circular motion. The eccentric end of the crankshaft 9 is hinged to one end of the connecting rod 8. As the crankshaft 9 continues to rotate, it can drive the connecting rod 8 to perform reciprocating push and pull actions. The other end of the connecting rod 8 is hinged to the swing frame 7 inside the mother liquor tank 101. Driven by the connecting rod 8, the swing frame 7 swings back and forth in the mother liquor tank 101 with a uniform rhythm. During the swinging process, each swing of the swing frame 7 can effectively agitate the liquid in the mother liquor tank 101, causing the mother liquor to continuously roll and flow in the tank. The crystal particles that are easy to settle due to static placement are continuously dispersed and are difficult to settle and aggregate, thus always maintaining the uniform suspension state of the crystals in the mother liquor and avoiding the occurrence of sedimentation.

[0051] When the mother liquor is transported to the mother liquor tank 101, the external negative pressure mechanism establishes negative pressure through the support cylinder 3. The first negative pressure pipe 221 of the filter chamber 22 at the bottom of the drum 2 forms an airflow channel with the help of the air extraction hole 41 and the first arc-shaped groove 411, so that the mother liquor enters the filter chamber 22 through the filter cloth 21 and the crystals are intercepted to form a filter cake layer.

[0052] When the drum 2 rotates and the filter chamber 22 is moved out of the mother liquor tank 101, the first negative pressure pipe 221 and the air extraction hole 41 are misaligned and closed, and the second negative pressure pipe 222 is connected to the second arc-shaped groove 412 on the rear side. Because the second negative pressure pipe 222 is close to the filter cloth 21 and is located at the upper end of the liquid level, it can maintain the negative pressure in the filter chamber 22 to retain some liquid, reduce the adhesion of crystals to the inner wall, and facilitate subsequent cleaning.

[0053] When the filter chamber 22 rotates to the top, the first negative pressure pipe 221 and the second negative pressure pipe 222 are both closed in a staggered manner with the air extraction hole 41. The T-shaped rod is pushed out after it abuts against the protrusion 421 of the drive sleeve 42, the drainage channel 51 is opened, and the residual liquid carrying crystals is discharged into the support cylinder 3, and then sent back to the mother liquor tank 101 for re-filtration by the circulation pump 6.

[0054] When the filter chamber 22 rotates to the position of the corresponding air blowing hole 44, the high-pressure gas delivered by the external blower enters the filter chamber 22 through the relevant channel, destroying the adhesion between the filter cake and the filter cloth 21. Then the scraper 102 scrapes off and collects the filter cake.

[0055] Throughout the process, the motor drives the crankshaft 9 to swing the swing frame 7 in the mother liquor tank 101 back and forth through the connecting rod 8, disturbing the mother liquor to prevent crystal sedimentation, ensuring its uniform distribution, and improving filtration efficiency.

[0056] The implementation principle of the crystallization filtration device for chemical product processing in this embodiment is as follows: Under a preset conveying pressure, the mother liquor to be filtered is continuously and stably conveyed to the mother liquor tank 101 through the inlet pipe. At the same time, the external negative pressure mechanism is connected to the support cylinder 3 through the flange pipe. At this time, the first negative pressure pipe 221 set in the filter chamber 22 at the bottom of the drum 2 forms an airflow channel with the inside of the support cylinder 3 through the air extraction hole 41 and the first arc-shaped groove 411 at the bottom of the distribution ring 4, so that the negative pressure acts on the filter chamber 22 at the bottom of the drum 2. Since the bottom of the drum 2 is immersed below the liquid surface of the mother liquor tank 101, under the action of negative pressure, the liquid in the mother liquor tank 101 enters the bottom filter chamber 22 through the filter cloth 21. The filter cloth 21 has a uniform pore structure, which can accurately trap crystals while allowing the liquid to pass through smoothly, so that the crystals carried in the mother liquor are trapped on the surface of the filter cloth 21 and gradually accumulate to form a filter cake layer.

[0057] As the drum 2 rotates clockwise, the filter chamber 22 gradually moves out of the mother liquor tank 101. The rotation speed of the drum 2 remains stable, ensuring that the filter chamber 22 can complete the corresponding operation at different positions. During this process, the first negative pressure pipe 221 in the filter chamber 22 is misaligned with the air extraction hole 41 on the distribution ring 4, causing the channel of the first negative pressure pipe 221 to close. At the same time, the second negative pressure pipe 222 in the filter chamber 22 corresponds to and connects with the second arc-shaped groove 412 behind the air extraction hole 41. The position design of the two arc-shaped slots 412 matches the layout of the second negative pressure pipe 222, ensuring timely connection and sealing. Since the end of the second negative pressure pipe 222 is close to the filter cloth 21 and is located at the upper end of the liquid level in the filter chamber 22, the negative pressure state in the filter chamber 22 can be continuously maintained through the second negative pressure pipe 222, so that some liquid remains in the filter chamber 22, reducing the probability of residual crystals adhering to the inner wall of the filter chamber 22, and creating conditions for subsequent cleaning operations of the filter chamber 22.

[0058] When the filter chamber 22 containing liquid rotates to its uppermost position with the drum 2, both the first negative pressure pipe 221 and the second negative pressure pipe 222 are completely misaligned with the air extraction port 41, so that both the first negative pressure pipe 221 and the second negative pressure pipe 222 are in a closed state. At this time, the end of the T-shaped rod 52 located at the uppermost position inside the drum 2 abuts against the protrusion 421 provided on the outside of the drive sleeve 42. The contact part between the T-shaped rod 52 and the protrusion 421 is treated with wear resistance to reduce wear caused by long-term friction. As the drum 2 continues to rotate, the T-shaped rod 52 is pushed outward under the action of the protrusion 421. The limiting ring 521 can limit the maximum push-out position of the T-shaped rod 52. The limiting ring 521 achieves rigid limiting through mechanical structure to ensure that the movement range of the T-shaped rod 52 is controlled within the preset range and to ensure that it does not displace excessively. During the outward movement of the T-shaped rod, the spring 522 is gradually... When compressed, the outer end of the T-shaped rod 52 separates from the drainage channel 51, making the drainage channel 51 open. At this time, when the external negative pressure mechanism is evacuating, it can act on the inside of the filter chamber 22 through the drainage hole 43 and the drainage channel 51. Under the action of negative pressure, the liquid remaining in the filter chamber 22, along with the crystals therein, is quickly discharged into the support cylinder 3 through the drainage channel 51 and the drainage hole 43. At the same time, the circulation pump 6 works to transport the liquid collected in the support cylinder 3 back to the mother liquor tank 101, ensuring that the liquid level inside the support cylinder 3 does not exceed the air extraction pipe at the top of the support cylinder 3, preventing liquid from entering the external negative pressure mechanism, and enabling the liquid to be filtered and separated again. When the filter chamber 22 leaves the top position, the T-shaped rod 52 gradually separates from the protrusion 421. Under the action of the spring force 522, the T-shaped rod 52 returns to the initial position, sealing the upper end of the drainage channel 51.

[0059] As the drum 2 continues to rotate, when the filter chamber 22 rotates to the position corresponding to the air blowing hole 44 on the outside of the distribution ring 4, the external blower starts to work. High-pressure gas enters the corresponding filter chamber 22 through the pipe, air blowing hole 44 and first negative pressure pipe 221. Under the action of positive pressure gas, the adhesion between the filter cake and the filter cloth 21 is destroyed. The impact force formed by the positive pressure gas can effectively break down the adsorption force between the filter cake and the filter cloth 21, creating conditions for the filter cake to fall off and causing the filter cake to separate from the filter cloth 21. As the drum 2 rotates further, the scraper 102 contacts the surface of the filter cloth 21 and scrapes the separated filter cake off the surface of the filter cloth 21, completing the filter cake collection operation. During the collection process, the filter cake falls into the preset collection device, realizing automated collection.

[0060] Throughout the filtration and separation process, the motor remains running. The motor's output shaft drives the crankshaft 9 to rotate. The eccentric structure at the end of the crankshaft 9, through the hinged connecting rod 8, converts the circular motion into reciprocating linear motion, thereby driving the hinged swing frame 7 inside the mother liquor tank 101 to reciprocate. The movement of the swing frame 7 causes the mother liquor in the mother liquor tank 101 to flow. The disturbance created by the flow can effectively break the sedimentation tendency of the crystals, making the crystals evenly dispersed in the mother liquor. This effectively prevents the crystals from settling in the mother liquor tank 101, ensuring the uniformity of crystal distribution in the mother liquor and improving the efficiency and effect of filtration and separation.

[0061] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principles described in this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A crystallization filtration device for chemical product processing, comprising a frame (1) and a mother liquor tank (101) disposed inside the frame (1), wherein a rotating drum (2) is rotatably connected inside the mother liquor tank (101), and a filter cloth (21) is provided on the surface of the rotating drum (2), characterized in that: The drum (2) has filter chambers (22) evenly arranged in the circumferential direction inside. Each filter chamber (22) is provided with a first negative pressure pipe (221) and a second negative pressure pipe (222). The second negative pressure pipe (222) is longer than the first negative pressure pipe (221), and the end of the second negative pressure pipe (222) is located close to the filter cloth (21). The upper end of the frame (1) is provided with a support cylinder (3), the front end of the drum (2) is rotatably connected to the support cylinder (3), the inside of the support cylinder (3) is provided with a distribution ring (4) rotatably connected to the drum (2), the air extraction hole (41) provided inside the distribution ring (4) is connected to the inside of the support cylinder (3), the first arc-shaped groove (411) at the bottom of the air extraction hole (41) can be connected to the first negative pressure pipe (221), the second arc-shaped groove (412) on the rear side of the air extraction hole (41) can be connected to the second negative pressure pipe (222), and the filter chamber (22) is provided with a drain assembly (5) that cooperates with the distribution ring (4).

2. The crystallization filtration device for chemical product processing according to claim 1, characterized in that: The drainage assembly (5) includes a drainage channel (51) disposed inside the drum (2). The drainage channels (51) are all connected to the interior of the corresponding filter chamber (22). The drum (2) is slidably connected with a T-shaped rod (52) that can seal the drainage channel (51). The drainage channels (51) distributed in a circular array can all be connected to the interior of the support cylinder (3) through the drainage hole (43) inside the distribution ring (4).

3. The crystallization filtration device for chemical product processing according to claim 2, characterized in that: The distribution ring (4) is provided with a drive sleeve (42) in the middle, and the outer side of the drive sleeve (42) is provided with protrusions (421) that can abut against the end of the T-shaped rod (52) in an axial array.

4. The crystallization filtration device for chemical product processing according to claim 2, characterized in that: Each of the T-shaped rods (52) is provided with a limit ring (521) at the end near the center of the drum (2), and each of the ends of the T-shaped rods (52) is fitted with a spring (522) that contacts the limit ring (521) to maintain the seal between the T-shaped rod (52) and the drainage channel (51).

5. The crystallization filtration device for chemical product processing according to claim 2, characterized in that: A circulation pump (6) is provided at the drain outlet at the lower end of the outer side of the support cylinder (3), and the outlet of the circulation pump (6) is connected to the inside of the mother liquor tank (101).

6. The crystallization filtration device for chemical product processing according to claim 1, characterized in that: The filter chamber (22) is inclined from front to back on the side closest to the center of the drum (2).

7. The crystallization filtration device for chemical product processing according to claim 2, characterized in that: The outer opening of each drainage channel (51) is inverted conical, and each opening of the drainage channel (51) is provided with a sealing ring (511) that can abut against the T-shaped rod (52).

8. The crystallization filtration device for chemical product processing according to claim 2, characterized in that: The distribution ring (4) is provided with an air blowing hole (44) that can communicate with the drainage channel (51). The outer opening of the air blowing hole (44) can communicate with the first negative pressure pipe (221) and the second negative pressure pipe (222). The air blowing hole (44) is connected to an external blower through a pipe.

9. The crystallization filtration device for chemical product processing according to claim 1, characterized in that: The mother liquor tank (101) is internally hinged with a swing frame (7), and the upper end of the swing frame (7) is hinged with a connecting rod (8). The lower ends of the two connecting rods (8) are hinged to the end of the crankshaft (9) which is rotatably connected to the bottom of the frame (1). The bottom of the frame (1) is provided with a motor that can drive the crankshaft (9) to rotate.

10. The crystallization filtration device for chemical product processing according to claim 1, characterized in that: The front end of the frame (1) is provided with a scraper (102), the upper edge of which can contact the filter cloth (21) on the surface of the drum (2) in a tangential direction.

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