Continuous dropwise addition filtration device

Abstract

The utility model relates to the technical field of chemical production, provide a kind of continuous dropwise adding filtering device, including crystallization unit, dropwise adding unit, filtering unit, conveying unit and back-feeding unit, and crystallization unit is used to accommodate mother liquor and is mixed with regulator to form crystal slurry for mother liquor;Dropwise adding unit is used to dropwise add regulator to crystallization unit;Filtering unit is used to separate the crystal component in crystal slurry, to obtain crystal product and filtrate;Conveying unit is arranged between crystallization unit and filtering unit, and conveying unit is used to convey crystal slurry to filtering unit;Back-feeding unit is arranged between crystallization unit and filtering unit, and back-feeding unit is used to convey filtrate to crystallization unit.In this way, the crystal separated from mother liquor and regulator can be separated from mother liquor and regulator during crystallization, avoiding the problem of long-term soaking of crystals in mother liquor and regulator, thereby avoiding the problem of impurities in mother liquor and mother liquor being absorbed and embedded by crystals, which is beneficial to improve the quality of crystal product.

Description

Technical Field

[0001] This utility model relates to the field of chemical production technology, and in particular to a continuous dripping filtration device. Background Technology

[0002] pH-adjusted free crystallization and salt-forming crystallization of acids and amines are two core separation and purification methods in organic synthesis, drug development, and chemical production. Both aim to obtain high-purity, easily processed, and stable target products. In the specific operation, a pH adjuster is added to the mother liquor, and after crystallization, the precipitated crystals are separated by filtration.

[0003] Currently, filtration is generally performed after complete crystal precipitation. During crystallization, due to the adsorption effect of the solid, impurities and mother liquor from the mother liquor are adsorbed onto the surface of the crystals, leading to a decrease in product quality. At the same time, the embedding and co-precipitation effects of the crystals can also cause adsorbed impurities to be embedded inside the crystals and precipitate out together, making it impossible to purify the impurities using conventional washing methods.

[0004] Therefore, how to solve the problem of poor product quality prepared by crystallization process in related technologies has become an important technical problem to be solved by those skilled in the art. Utility Model Content

[0005] This invention provides a continuous drip filtration device to solve the defect of poor product quality prepared by crystallization process in related technologies.

[0006] This utility model provides a continuous drip filtration device, comprising: A crystallization unit is used to contain the mother liquor and to mix the mother liquor with a regulator to form a crystal slurry; A dropping unit is used to drop the regulator into the crystallization unit; A filtration unit is used to separate the crystalline components from the crystal slurry to obtain crystalline products and filtrate; A conveying unit is disposed between the crystallization unit and the filtration unit, and the conveying unit is used to convey the crystal slurry to the filtration unit; A return feed unit is disposed between the crystallization unit and the filtration unit, and the return feed unit is used to transport the filtrate into the crystallization unit.

[0007] According to the present invention, a continuous dripping filtration device is provided, wherein the filtration unit comprises: The tank body has a liquid outlet at its bottom, and the feed end of the return unit is connected to the liquid outlet. The centrifugal filter screen has a cylindrical structure with one end open. The centrifugal filter screen is rotatably mounted in the tank. There is a gap between the side wall of the centrifugal filter screen and the side wall of the tank. The discharge end of the conveying unit extends into the interior of the centrifugal filter screen through the open end of the centrifugal filter screen. A centrifugal drive mechanism is used to drive the centrifugal filter screen to rotate relative to the tank.

[0008] According to the continuous dripping filtration device provided by this utility model, the centrifugal filter screen is arranged at an angle to the vertical direction relative to the rotation axis of the tank, and the continuous dripping filtration device further includes: The scraping unit includes at least a scraper for scraping off the crystalline product adhering to the inner wall of the centrifugal filter, the blade of the scraper corresponding to the inner top wall of the centrifugal filter; A collection unit is used to collect the crystal product scraped off by the scraping unit. In the vertical direction, the projection area of ​​the scraper is located inside the projection area of ​​the collection unit.

[0009] According to the continuous drip filtration device provided by this utility model, the scraping unit further includes: A detection mechanism is disposed inside the centrifugal filter screen, and the detection mechanism is used to detect the thickness of the crystal product attached to the inner wall of the centrifugal filter screen; A scraper drive mechanism is used to drive the scraper to move closer to or away from the inner top wall of the centrifugal filter.

[0010] According to the continuous drip filtration device provided by this utility model, the centrifugal filter screen is arranged horizontally relative to the rotation axis of the tank body, the open end of the centrifugal filter screen faces the side of the tank body, the tank body is provided with a clearance hole corresponding to the open end of the centrifugal filter screen, and the collection unit includes: The conveyor belt mechanism has a first end that extends into the interior of the centrifugal filter through the clearance hole and the open end of the centrifugal filter, and the first end of the conveyor belt mechanism is located below the scraping unit, while the second end of the conveyor belt mechanism is located outside the tank.

[0011] According to the continuous drip filtration device provided by this utility model, the crystallization unit includes: The crystallization vessel is provided with a receiving cavity and a crystal slurry outlet, a filtrate inlet, a regulator inlet, and a filtrate outlet connected to the receiving cavity. The crystal slurry outlet is connected to the conveying unit, the filtrate inlet is connected to the return conveying unit, and the regulator inlet is connected to the dripping unit. A stirring mechanism is disposed inside the crystallization vessel, and the stirring mechanism is used to stir the substances inside the crystallization vessel; A temperature control mechanism is provided in the crystallization vessel, and the temperature control mechanism is used to adjust the temperature of the crystallization vessel.

[0012] According to the present invention, a continuous dripping filtration device is provided, wherein the dripping unit includes: A storage tank for containing the regulator, wherein the height of the storage tank is greater than the height of the crystallization vessel; A dripping line is provided between the liquid storage tank and the crystallization vessel. The first end of the dripping line is connected to the bottom wall of the liquid storage tank, and the second end of the dripping line is connected to the top wall of the crystallization vessel. A flow regulating valve is provided in the dripping pipeline, and the flow regulating valve is used to regulate the flow rate of the regulating agent in the dripping pipeline.

[0013] According to the continuous dripping filtration device provided by this utility model, the dripping unit further includes: A replenishment line, the second end of which is connected to the top wall of the storage tank, and the first end of which is used to connect to a regulator source.

[0014] According to the continuous drip filtration device provided by this utility model, the conveying unit includes: The discharge pipe has a first end connected to the crystal slurry outlet and a second end extending into the centrifugal filter through the open end of the centrifugal filter. A slurry pump is installed in the discharge pipeline, and the slurry pump is used to transport the crystal slurry in the crystallization kettle to the interior of the centrifugal filter.

[0015] According to the continuous drip filtration device provided by this utility model, the return feed unit includes: A return liquid pipeline, wherein the first end of the return liquid pipeline is connected to the outlet, and the second end of the return liquid pipeline is connected to the filtrate inlet; A power pump is installed in the return pipeline, and the power pump is used to transport the filtrate in the tank to the crystallization vessel.

[0016] The continuous dripping filtration device provided by this utility model includes a crystallization unit, a dripping unit, a filtration unit, a conveying unit, and a return unit. The dripping unit adds a regulator to the crystallization unit, which contains the mother liquor and allows it to mix with the regulator to form a crystal slurry. The conveying unit is located between the crystallization unit and the filtration unit, and it conveys the crystal slurry to the filtration unit. The filtration unit separates the crystalline components from the crystal slurry to obtain a crystalline product and filtrate. The return unit is located between the crystallization unit and the filtration unit, and it conveys the filtrate back to the crystallization unit. By gradually adding the regulator to the crystallization unit through the dripping unit, crystals gradually precipitate in the crystallization unit, which contains a crystal slurry. As crystals precipitate, the crystal content in the slurry gradually increases. During the gradual crystal precipitation process, the conveying unit conveys the crystal slurry to the filtration unit for filtration, filtering out the crystalline product. The filtrate is then conveyed back to the crystallization unit by the return unit to continue participating in crystallization. This setup allows the precipitated crystals to be separated from the mother liquor and regulator during the crystallization process, reducing the time the crystals coexist with the mother liquor and avoiding the problem of prolonged soaking of the crystals in the mother liquor and regulator. It also reduces solid adsorption and co-precipitation, thereby preventing impurities in the mother liquor from being adsorbed by the crystals or being embedded in the crystals. This helps improve the quality of the crystal products and solves the problem of poor product quality prepared by crystallization processes in related technologies. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structural principle of the continuous dripping filtration device provided by this utility model.

[0019] Figure label: 1. Tank body; 2. Centrifugal filter; 3. Centrifugal drive mechanism; 4. Scraper; 5. Detection mechanism; 6. Scraper drive mechanism; 7. Clearance hole; 8. Conveyor belt mechanism; 9. Crystallization kettle; 10. Storage tank; 11. Dropping pipeline; 12. Flow regulating valve; 13. Additive pipeline; 14. Discharge pipeline; 15. Slurry pump; 16. Return pipeline; 17. Power pump; 18. Agitator; 19. Agitator motor; 20. Jacket. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] The following is combined with Figure 1 This invention describes a continuous drip filtration device.

[0022] like Figure 1 As shown, the continuous dripping filtration device provided in this embodiment of the present invention includes a crystallization unit, a dripping unit, a filtration unit, a conveying unit, and a return conveying unit.

[0023] Specifically, the dropping unit is used to drop a regulator into the crystallization unit, which is used to contain the mother liquor and allow the mother liquor and regulator to mix to form a crystal slurry.

[0024] A conveying unit is located between the crystallization unit and the filtration unit, and is used to transport the crystal slurry to the filtration unit. The filtration unit is used to separate the crystalline components from the crystal slurry to obtain the crystalline product and filtrate. A return conveying unit is located between the crystallization unit and the filtration unit, and is used to transport the filtrate back to the crystallization unit.

[0025] A regulator is gradually added dropwise to the crystallization unit via a dropping unit, causing crystals to gradually precipitate within the crystallization unit. The substance in the crystallization unit is a crystal slurry, and the crystal content in the slurry gradually increases as crystals precipitate. During the gradual crystal precipitation process, the crystal slurry is transported to a filtration unit via a conveying unit for filtration, filtering out the crystal product. The filtrate is then returned to the crystallization unit via a return unit to continue participating in crystallization.

[0026] This setup allows the precipitated crystals to be separated from the mother liquor and regulator during the crystallization process, avoiding the problem of prolonged soaking of crystals in the mother liquor and regulator. This prevents impurities in the mother liquor from being adsorbed or embedded by the crystals, thus improving the quality of the crystal products and solving the problem of poor product quality in related technologies prepared by crystallization processes.

[0027] In this embodiment of the invention, the filtration unit includes a tank 1, a centrifugal filter 2, and a centrifugal drive mechanism 3.

[0028] The centrifugal filter 2 has a cylindrical structure with one open end. It is rotatably mounted inside the tank 1, and a centrifugal drive mechanism 3 drives the centrifugal filter 2 to rotate relative to the tank 1. During this rotation, the high-speed rotation generates centrifugal force, which throws the crystal slurry against the inner wall of the filter 2, rapidly separating the crystal product from the filtrate, thus achieving efficient solid-liquid separation. This immediate separation method avoids prolonged soaking of the crystal product in the mother liquor, effectively preventing impurities from being adsorbed or trapped, and significantly improving the quality of the crystal product.

[0029] There is a gap between the side wall of the centrifugal filter 2 and the side wall of the tank 1. This gap provides space for the filtrate to be collected and flow after passing through the centrifugal filter 2, which can prevent the filtrate from accumulating and affecting the filtration effect.

[0030] The discharge end of the conveying unit extends into the interior of the centrifugal filter 2 through the open end of the centrifugal filter 2, which can directly convey the crystal slurry into the centrifugal filter 2 for separation, ensuring the timeliness of the separation process.

[0031] A liquid outlet is provided at the bottom of tank 1, and the feed end of the return unit is connected to the liquid outlet. This facilitates the timely collection and return of the filtered liquid to the crystallization unit, realizing the recycling of the filtrate to continue participating in the crystallization reaction, improving the raw material utilization rate and ensuring the stability of continuous production.

[0032] The centrifugal drive mechanism 3 may, but is not limited to, use a motor.

[0033] The mesh size of centrifugal filter 2 is determined based on the particle size of the crystalline product.

[0034] The material of tank body 1 may be, but is not limited to, enamel, glass, polytetrafluoroethylene, stainless steel, Hastelloy or composite materials.

[0035] In this embodiment, the continuous drip filtration device further includes a scraping unit and a collection unit to remove and collect the filtered crystal products.

[0036] The scraping unit includes at least a scraper 4, which is used to scrape off the crystal products attached to the inner wall of the centrifugal filter screen 2, and to peel off the crystal products after centrifugation from the centrifugal filter screen 2 in a timely manner, so as to avoid the problem of excessive accumulation of crystal products on the centrifugal filter screen 2, which would affect the filtration efficiency.

[0037] The centrifugal filter 2 is angled relative to the vertical direction by its axis of rotation with respect to the tank 1. Specifically, the axis of rotation of the centrifugal filter 2 relative to the tank 1 can be perpendicular to the vertical direction, that is, the axis of rotation of the centrifugal filter 2 relative to the tank 1 is set horizontally. Figure 1 As shown.

[0038] The blade of scraper 4 corresponds to the inner top wall of the centrifugal filter screen 2. The blade of scraper 4 acts on the inner top wall of the centrifugal filter screen 2, and the crystal product scraped off by scraper 4 falls downwards under gravity, preventing the scraped crystal product from being carried away again by the high-speed rotating centrifugal filter screen 2, thus improving the reliability of the discharge. A certain space is provided below scraper 4 for placing a collection unit to collect the crystal product scraped off by the scraping unit.

[0039] In the vertical direction, the projection area of ​​the scraper 4 is located inside the projection area of ​​the collection unit, ensuring that the crystal products falling from the scraper 4 can fall accurately into the collection unit, effectively preventing the crystal products from falling into the tank 1, and helping to improve the collection rate of crystal products.

[0040] To prevent crystal products or slurry from accidentally flowing out of the open end of the centrifugal filter 2 during rotation, a baffle can be installed at the open end of the centrifugal filter 2 to block the crystal products or slurry, thus preventing the crystal products from falling out and the slurry from flowing directly into the tank 1 without filtration.

[0041] In this embodiment, the scraping unit also includes a detection mechanism 5 and a scraper driving mechanism 6.

[0042] The detection mechanism 5 is located inside the centrifugal filter 2 and is used to detect the thickness of the crystal product adhering to the inner wall of the centrifugal filter 2. The scraper driving mechanism 6 is used to drive the scraper 4 to move closer to or away from the inner top wall of the centrifugal filter 2.

[0043] In this way, by monitoring the thickness of the crystal product on the inner wall of the centrifugal filter 2 in real time, the scraping operation can be carried out when the crystal product reaches the preset thickness, realizing the automation and intelligent control of the scraping process, avoiding the problem of low discharge efficiency caused by untimely or excessive scraping, and ensuring the stability and efficiency of the device operation.

[0044] The aforementioned detection mechanism 5 may be, but is not limited to, a laser rangefinder. The laser rangefinder is installed inside the centrifugal filter 2 and is used to emit a laser beam toward the inner wall of the centrifugal filter 2. The specific location of the laser rangefinder within the centrifugal filter 2 is not limited, as long as the laser beam can be directly emitted to the inner wall of the centrifugal filter 2.

[0045] Specifically, the centrifugal filter 2 has a circular cross-section, which ensures that the laser beam emitted by the laser rangefinder is along the diameter of the centrifugal filter 2. Simultaneously, the scraper, scraper drive mechanism, etc., must not be in the propagation path of the laser beam.

[0046] When there are no crystalline products attached to the inner wall of the centrifugal filter 2, the laser rangefinder measures the distance between itself and the inner wall of the centrifugal filter 2. As filtration proceeds, a laser beam is emitted onto the surface of the crystalline products attached to the centrifugal filter 2, and the laser rangefinder measures the distance between itself and the surface of the crystalline products. By comparing the distance between the laser rangefinder and the inner wall of the centrifugal filter 2 and the distance between the laser rangefinder and the surface of the crystalline products, the thickness of the crystalline products attached to the inner wall of the centrifugal filter 2 can be determined.

[0047] The scraper drive mechanism 6 can be configured as a linkage mechanism driven by a hydraulic cylinder, or as a screw and nut drive, gear and rack drive, or other similar structures. The specific structure of the scraper drive mechanism 6 is not limited, as long as it can drive the scraper 4 to approach or move away from the inner top wall of the centrifugal filter screen 2.

[0048] In this embodiment, the centrifugal filter 2 is arranged horizontally relative to the rotation axis of the tank 1, and the open end of the centrifugal filter 2 faces the side of the tank 1. The tank 1 is provided with a clearance hole 7, which corresponds to the open end of the centrifugal filter 2. The clearance hole 7 provides a channel for the subsequent collection unit to enter the interior of the centrifugal filter 2 for operation.

[0049] The collection unit includes a conveyor belt mechanism 8, which enables continuous collection of crystal products, improving the automation level and production efficiency of the continuous drip filtration device.

[0050] The first end of the conveyor belt mechanism 8 extends into the interior of the centrifugal filter 2 through the clearance hole 7 and the open end of the centrifugal filter 2, and the first end of the conveyor belt mechanism 8 is located below the scraping unit. This arrangement ensures that the crystal products scraped off by the scraping unit can fall precisely onto the first end of the conveyor belt mechanism 8, achieving efficient collection and avoiding the problem of crystal products falling off.

[0051] The second end of the conveyor belt mechanism 8 is located outside the tank 1, and the crystal product is transported to the outside of the tank 1 using the conveyor belt mechanism 8. An open-top collection container can be set below the second end of the conveyor belt mechanism 8, and the collection container can directly hold the crystal product from the second end of the conveyor belt mechanism 8, forming a continuous operation of dripping, crystallization, separation and discharge.

[0052] The aforementioned detection mechanism 5, slurry pump 15, and scraper drive mechanism 6 are all electrically connected to the control system, enabling automated control of the continuous drip filtration device. Furthermore, when the control system controls the scraper drive mechanism 6 to operate, it needs to stop the slurry pump 15. In other words, when the centrifugal filter screen 2 rotates at high speed for centrifugal separation, the slurry pump 15 will not deliver crystal slurry to the centrifugal filter screen 2. This prevents incompletely separated liquid from being scraped off along with the crystal product to the conveyor belt mechanism 8, thus improving the quality of the crystal product.

[0053] In this embodiment of the invention, the crystallization unit includes a crystallization vessel 9, a stirring mechanism, and a temperature control mechanism.

[0054] The crystallization vessel 9 is equipped with a receiving cavity, a crystal slurry outlet, a filtrate inlet, a regulator inlet, and a filtrate outlet. The crystal slurry outlet, filtrate inlet, regulator inlet, and filtrate outlet are all connected to the receiving cavity.

[0055] The crystal slurry outlet is connected to the conveying unit so that the conveying unit can promptly deliver the generated crystal slurry to the centrifugal filter 2.

[0056] The filtrate inlet is connected to the return unit, which facilitates the return of the filtrate in tank 1 to crystallizer 9 for recycling, which helps to improve the total yield of materials and save raw material costs.

[0057] The regulator inlet is connected to the dropping unit, allowing the regulator to be added continuously or as needed during the crystallization process.

[0058] The filtrate outlet is used to discharge the remaining liquid after crystallization is complete.

[0059] A stirring mechanism is installed inside the crystallization vessel 9 to stir the substances inside. On the one hand, it can make the solution concentration distribution in the crystallization vessel 9 uniform, and on the other hand, it can effectively suspend the crystals in the mother liquor, which can promote the uniform growth of crystals, effectively prevent crystal agglomeration or sedimentation, and help obtain high-quality crystal products with uniform particle size distribution.

[0060] The stirring mechanism includes a stirring paddle 18 and a stirring motor 19. The stirring paddle 18 is rotatably mounted inside the crystallization vessel 9, and the axis of rotation of the stirring paddle 18 is arranged in the vertical direction. The stirring motor 19 is used to drive the stirring paddle 18 to rotate relative to the crystallization vessel 9.

[0061] A temperature control mechanism is installed in the crystallization vessel 9 to regulate its temperature. By heating or cooling the crystallization vessel 9, the temperature inside it is brought to the required level for the crystallization process. Temperature is a key parameter affecting solute solubility; precise temperature control can directly regulate the supersaturation level of the solution, which is beneficial for controlling the balance between crystal nucleation and growth.

[0062] Specifically, the temperature control mechanism can be configured as a jacketed structure, comprising a jacket 20 and a heat exchange medium circulation system. The jacket 20 is fitted outside the crystallization vessel 9, and has flow channels for the heat exchange medium. The heat exchange medium circulation system is connected to the flow channels of the jacket 20, supplying the jacket 20 with a heat exchange medium at the target temperature. Through heat exchange between the heat exchange medium and the jacket 20, between the jacket 20 and the crystallization vessel 9, and between the crystallization vessel 9 and the internal materials, the temperature of the crystallization vessel 9 and its internal materials can be controlled. The target temperature of the crystallization vessel 9 and its internal materials needs to be determined based on the characteristics of the crystallization material.

[0063] The heat exchange medium circulation system has the function of heating or cooling the heat exchange medium, and can realize the temperature regulation of the heat exchange medium. The heating or cooling of the heat exchange medium circulation system can be controlled as needed.

[0064] The heat exchange medium can be, but is not limited to, water.

[0065] The crystallization vessel 9 can be made of enamel, glass, polytetrafluoroethylene, stainless steel, Hastelloy, or composite materials.

[0066] In this embodiment of the present invention, the dripping unit includes a liquid storage tank 10, a dripping pipeline 11, and a flow regulating valve 12.

[0067] The storage tank 10 is used to hold the regulator, and its height is greater than that of the crystallization vessel 9. The regulator can flow into the crystallization vessel 9 by its own gravity, without the need for an additional power pump. This not only saves energy and simplifies the structure of the dropping unit, but also enables stable and continuous dropping, avoiding flow pulsations that may be caused by pumping, which is conducive to the stable progress of the crystallization process.

[0068] The liquid storage tank 10 can be made of wood, steel, light steel, aluminum alloy, carbon fiber, or composite materials.

[0069] A dripping line 11 is positioned between the storage tank 10 and the crystallization vessel 9. The first end of the dripping line 11 is connected to the bottom wall of the storage tank 10, and the second end is connected to the top wall of the crystallization vessel 9. This ensures that the regulator can be smoothly drawn from the bottom of the storage tank 10 and dripped into the top of the crystallization vessel 9, facilitating uniform mixing of the regulator with the mother liquor stirred by the stirring mechanism within the crystallization vessel 9. This promotes uniform crystal growth and avoids the problem of excessively high local concentrations leading to a decrease in crystal quality.

[0070] A flow regulating valve 12 is installed in the dripping line 11 and is used to regulate the flow rate of the regulator in the dripping line 11. The flow regulating valve 12 allows for precise control of the regulator's dripping rate, thereby precisely regulating the crystallization rate. This ensures that the crystal precipitation rate matches the filtration separation rate, guaranteeing the smooth operation of the entire continuous dripping filtration process. This is crucial for controlling crystal morphology, particle size distribution, and improving the purity and quality of the final product.

[0071] In a further embodiment, the dripping unit also includes a replenishment line 13, the second end of which is connected to the top wall of the storage tank 10, and the first end of which is connected to a regulator source. The replenishment line 13 can replenish the regulator in the storage tank 10, thereby ensuring a continuous supply of regulator to the dripping unit, thus achieving continuous and stable operation of the entire device without interrupting the production process due to regulator depletion.

[0072] Furthermore, the replenishment line 13 is connected to the top wall of the storage tank 10, while the dripping line 11 is connected to the bottom wall of the storage tank 10. The method of replenishing from the top and dripping from the bottom can effectively avoid the problem of the replenishment process disturbing the dripping process. For example, it can prevent air bubbles or pressure fluctuations generated during replenishment from affecting the flow rate of the regulator in the dripping line 11, thereby ensuring the stability and accuracy of the dripping speed controlled by the flow regulating valve 12.

[0073] In this embodiment, the conveying unit includes a discharge pipe 14 and a slurry pump 15. The first end of the discharge pipe 14 is connected to the crystal slurry outlet, and the second end of the discharge pipe 14 extends into the centrifugal filter 2 through its open end. This structural design ensures that the crystal slurry is directly and accurately conveyed to the core area of ​​the filtration and separation process, avoiding material splashing or loss during conveying and laying the foundation for subsequent efficient solid-liquid separation.

[0074] A slurry pump 15 is installed in the discharge pipeline 14. The slurry pump 15 is used to transport the crystal slurry in the crystallization kettle 9 to the interior of the centrifugal filter 2. Powered by the slurry pump 15, the crystal slurry can be continuously and stably transported from the crystallization unit to the filtration unit, ensuring a continuous operation process of crystallization and filtration simultaneously throughout the entire device. This uninterrupted transport and filtration mode allows newly precipitated crystals to be separated in a timely manner, effectively avoiding the problem of crystals adsorbing or being buried by impurities due to prolonged immersion in the mother liquor, thereby significantly improving the purity and quality of the crystal product.

[0075] In this embodiment, the return unit includes a return pipeline 16 and a power pump 17.

[0076] The first end of the return liquid pipeline 16 is connected to the liquid outlet, and the second end of the return liquid pipeline 16 is connected to the filtrate inlet. This provides a dedicated channel for the filtrate separated by the filtration unit to return to the crystallization unit, realizing the recycling of the filtrate and avoiding the waste of raw materials caused by the direct discharge of filtrate containing unreacted mother liquor and regulators, thus effectively improving the utilization rate of raw materials and economic benefits.

[0077] A power pump 17 is installed in the return liquid pipeline 16. The power pump 17 is used to transport the filtrate in the tank 1 to the crystallization vessel 9. By providing stable power for the return of the filtrate through the power pump 17, it is possible to ensure that the filtrate is returned to the crystallization vessel 9 in a timely and continuous manner, thereby maintaining the stability of the liquid level in the crystallization vessel 9. This provides a reliable guarantee for the continuous and stable operation of the entire device, allowing the crystallization and filtration processes to proceed uninterrupted, and ensuring the uniformity and stability of the final product quality.

[0078] The aforementioned power pump 17 can be, but is not limited to, a diaphragm pump. When the diaphragm pump is working, the conveyed material is completely isolated from the pump's transmission components by the diaphragm, effectively preventing contamination of the filtrate by lubricating oil or other media from the power pump 17 during the return process, thus ensuring the high purity of the final product. Furthermore, the diaphragm pump has strong corrosion resistance, enabling it to adapt to filtrates with different chemical properties, preventing pump body corrosion and damage, extending service life, and reducing maintenance costs.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A continuous drip filtration device, characterized in that, include: A crystallization unit is used to contain the mother liquor and to mix the mother liquor with a regulator to form a crystal slurry; A dropping unit is used to drop the regulator into the crystallization unit; A filtration unit is used to separate the crystalline components from the crystal slurry to obtain crystalline products and filtrate; A conveying unit is disposed between the crystallization unit and the filtration unit, and the conveying unit is used to convey the crystal slurry to the filtration unit; A return feed unit is disposed between the crystallization unit and the filtration unit, and the return feed unit is used to transport the filtrate into the crystallization unit.

2. The continuous dripping filtration device according to claim 1, characterized in that, The filtering unit includes: Tank (1), the bottom of the tank (1) is provided with a liquid outlet, and the feed end of the return unit is connected to the liquid outlet; The centrifugal filter (2) has a cylindrical structure with one end open. The centrifugal filter (2) is rotatably disposed inside the tank (1) with a fixed axis. There is a gap between the side wall of the centrifugal filter (2) and the side wall of the tank (1). The discharge end of the conveying unit extends into the interior of the centrifugal filter (2) through the open end of the centrifugal filter (2). Centrifugal drive mechanism (3) is used to drive the centrifugal filter (2) to rotate relative to the tank (1).

3. The continuous dripping filtration device according to claim 2, characterized in that, The centrifugal filter screen (2) is set at an angle to the vertical direction relative to the rotation axis of the tank (1), and the continuous drip filtration device further includes: The scraping unit includes at least a scraper (4) for scraping off the crystal products attached to the inner wall of the centrifugal filter (2), with the blade of the scraper (4) corresponding to the inner top wall of the centrifugal filter (2). The collection unit is used to collect the crystal product scraped by the scraping unit. In the vertical direction, the projection area of ​​the scraper (4) is located inside the projection area of ​​the collection unit.

4. The continuous dripping filtration device according to claim 3, characterized in that, The scraping unit further includes: The detection mechanism (5) is located inside the centrifugal filter (2) and is used to detect the thickness of the crystal product attached to the inner wall of the centrifugal filter (2). The scraper drive mechanism (6) is used to drive the scraper (4) to approach or move away from the inner top wall of the centrifugal filter (2).

5. The continuous dripping filtration device according to claim 3, characterized in that, The centrifugal filter (2) is arranged horizontally relative to the rotation axis of the tank (1), and the open end of the centrifugal filter (2) faces the side of the tank (1). The tank (1) is provided with a clearance hole (7), which corresponds to the open end of the centrifugal filter (2). The collection unit includes: The first end of the conveyor belt mechanism (8) extends into the interior of the centrifugal filter (2) through the clearance hole (7) and the open end of the centrifugal filter (2), and the first end of the conveyor belt mechanism (8) is located below the scraping unit, and the second end of the conveyor belt mechanism (8) is located outside the tank (1).

6. The continuous dripping filtration device according to claim 2, characterized in that, The crystallization unit includes: The crystallization vessel (9) is provided with a receiving cavity and a crystal slurry outlet, a filtrate inlet, a regulator inlet and a filtrate outlet connected to the receiving cavity. The crystal slurry outlet is connected to the conveying unit, the filtrate inlet is connected to the return conveying unit, and the regulator inlet is connected to the dripping unit. A stirring mechanism is provided inside the crystallization vessel (9), and the stirring mechanism is used to stir the substance inside the crystallization vessel (9); A temperature control mechanism is provided in the crystallization vessel (9), and the temperature control mechanism is used to adjust the temperature of the crystallization vessel (9).

7. The continuous dripping filtration device according to claim 6, characterized in that, The dripping unit includes: A storage tank (10) is used to contain the regulator, and the height of the storage tank (10) is greater than the height of the crystallization vessel (9); A dripping pipe (11) is provided between the liquid storage tank (10) and the crystallization vessel (9). The first end of the dripping pipe (11) is connected to the bottom wall of the liquid storage tank (10), and the second end of the dripping pipe (11) is connected to the top wall of the crystallization vessel (9). A flow regulating valve (12) is provided in the dripping pipeline (11) and is used to regulate the flow rate of the regulator in the dripping pipeline (11).

8. The continuous drip filtration device according to claim 7, characterized in that, The dripping unit further includes: The replenishment line (13) has its second end connected to the top wall of the storage tank (10), and its first end is used to connect to the regulator source.

9. The continuous dripping filtration device according to claim 6, characterized in that, The conveying unit includes: The discharge pipe (14) has its first end connected to the crystal slurry outlet, and its second end extends into the centrifugal filter (2) through the open end of the centrifugal filter (2). A slurry pump (15) is installed in the discharge pipeline (14). The slurry pump (15) is used to transport the crystal slurry in the crystallization vessel (9) to the interior of the centrifugal filter (2).

10. The continuous dripping filtration device according to claim 6, characterized in that, The return unit includes: The return liquid pipeline (16) has its first end connected to the outlet and its second end connected to the filtrate inlet. A power pump (17) is installed in the return pipeline (16) and is used to transport the filtrate in the tank (1) to the crystallization vessel (9).

Images