A continuous filtration and drying device and treatment method for 1,4-dihydroxyanthraquinone

Abstract

This invention belongs to the field of 1,4-dihydroxyanthraquinone production technology, specifically a continuous filtration and drying device and method for 1,4-dihydroxyanthraquinone, including the following steps: Step 1: The reactant material containing 1,4-dihydroxyanthraquinone is continuously fed into the filtration area of ​​the integrated filtration and drying device through a conveying pump. The filtration area is equipped with multi-layer metal sintered filter plates with a pore size of 0.5-2μm and a filter cake thickness controlled at 3-8cm. In this invention, during the drying process, the synergistic effect of heating frame heating and nitrogen purging, combined with a vacuum environment and nitrogen purging and turning, effectively improves drying efficiency and uniformity, shortens drying time, and makes the particle size of the pulverized material controllable. Moreover, the entire process is carried out in a closed environment. Combined with the use of 316L stainless steel, the purity and quality of the product are maximized, manual intervention is reduced, and production efficiency is improved, making it suitable for the needs of large-scale continuous industrial production.

Description

Technical Field

[0001] This invention belongs to the field of 1,4-dihydroxyanthraquinone production technology, specifically a continuous filtration and drying device and processing method for 1,4-dihydroxyanthraquinone. Background Technology

[0002] 1,4-Dihydroxyanthraquinone is an important fine chemical intermediate. Its preparation typically begins with phthalic anhydride and p-chlorophenol as starting materials. In the presence of 20% fuming sulfuric acid, using boric acid as a dispersant, a condensation reaction is first carried out to obtain the condensation product, followed by hydrolysis to obtain the target product. This product requires further fine post-processing steps such as filtration, washing, drying, and pulverization to obtain the final product.

[0003] As a high-purity chemical intermediate, 1,4-dihydroxyanthraquinone is widely used not only in the manufacture of safe and environmentally friendly dyes and pigments, but also plays a crucial role in the synthesis of pharmaceutical raw materials and the manufacturing of pharmaceuticals, having a key impact on the purity and physicochemical properties of the final product. Therefore, in the production process, especially during the post-processing of 1,4-dihydroxyanthraquinone after sublimation purification, efficient and thorough dehydration and drying of the filter cake washed during processing is particularly important.

[0004] However, existing technologies for the filtration, dehydration, and drying of 1,4-dihydroxyanthraquinone often encounter technical bottlenecks. Traditional processes often simply use filter plates for interception filtration to obtain a filter cake. However, due to the small particle size and large specific surface area of ​​1,4-dihydroxyanthraquinone crystals, a dense microporous clogging layer or high-resistance filter cake easily forms on the filter plate surface during filtration. This significantly reduces the permeation efficiency of the reactants containing 1,4-dihydroxyanthraquinone on the filter plate surface, severely restricting the filtration speed and prolonging the production cycle. Simultaneously, the lag in filtration efficiency directly leads to unsatisfactory final drying efficiency and high energy consumption, making it difficult to meet the demands of modern chemical and pharmaceutical manufacturing industries for continuous and efficient production. Therefore, a continuous filtration and drying device and method for 1,4-dihydroxyanthraquinone is needed to solve these problems. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention proposes a continuous filtration and drying apparatus and method for 1,4-dihydroxyanthraquinone. This invention primarily addresses the problem in existing technologies where the filtration, dehydration, and drying of 1,4-dihydroxyanthraquinone results in limited filtration speed, leading to low filtration efficiency and prolonged production cycles.

[0006] The technical solution adopted by this invention to solve its technical problem is: a continuous filtration and drying method for 1,4-dihydroxyanthraquinone; comprising the following steps: Step 1: The reactant containing 1,4-dihydroxyanthraquinone is continuously fed into the filtration zone of the integrated filtration and drying device via a pump. The filtration zone is equipped with multiple layers of sintered metal filter plates with a pore size of 0.5-2μm. The material is pressurized and filtered under an operating pressure of 0.3-0.6MPa, and the filter cake thickness is controlled at 3-8cm. The filtrate is collected by the filter plates and continuously discharged from the filtrate outlet, thus achieving preliminary solid-liquid separation. Step 2: After filtration, the filter cake is pushed to the drying zone by the built-in filter cake pushing mechanism. The drying zone adopts a combination of heating frame heating and nitrogen purging. Heat transfer oil at 120-150℃ is introduced into the heating frame, and nitrogen gas preheated to 80-100℃ is introduced from the bottom of the drying zone at a flow rate of 0.5-1.2 m³ / h. The filter cake is vacuum dried under a vacuum degree of -0.08 to -0.095 MPa for 2-4 hours. Step 3: The dried 1,4-dihydroxyanthraquinone solid is crushed to a particle size of 50-150 mesh by a crushing device, and then conveyed to the finished product silo by a screw conveyor.

[0007] A continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone includes a filtration unit, a drying unit, and a pulverizing unit connected in sequence. The filtration unit and the drying unit are seamlessly connected via a connecting channel, and the drying unit and the pulverizing unit are seamlessly connected via a feeding channel. The filtration unit includes a filter box, with a feed pipe connected to the left side of the filter box. A solenoid valve is installed outside the feed pipe, and a delivery pump is connected to the end of the feed pipe. A filter plate is horizontally arranged inside the filter box, and a horizontally movable pushing mechanism is configured inside the filter box. A first partition is vertically slidably connected to the right side wall of the filter box, and a third hydraulic cylinder is connected to the first partition. The third hydraulic cylinder is mounted on the filter box via a first bracket. A filtrate collection chamber is correspondingly provided below the filter plate, and the bottom of the collection chamber is connected to a filtrate outlet. The drying unit includes a drying box, with support legs installed below the drying box. A heating frame is provided on the inner wall of the drying box. A circulating pump is connected to the top, with its inlet end connected to the drying chamber and its outlet end connected to a connecting pipe. A heater is installed outside the connecting pipe, and an air supply head is installed above the heater outside the connecting pipe. The bottom end of the connecting pipe is connected to the drying chamber. A vacuum pump is connected to the top of the drying chamber, and a material guiding mechanism is provided on the back of the drying chamber. A second partition is slidably connected inside the connecting channel, and a fourth hydraulic cylinder is connected to the second partition. The fourth hydraulic cylinder is mounted on the connecting channel via a second bracket. A third partition is slidably connected inside the right side wall of the drying chamber, and a fifth hydraulic cylinder is connected to the third partition. The fifth hydraulic cylinder is mounted on the drying chamber via a third bracket. The pulverizing device includes a pulverizing chamber, on which a second drive motor is installed. The output shaft of the second drive motor is connected to a rotating shaft, and pulverizing blades are installed outside the rotating shaft. A screen is provided below the pulverizing blades, and a screw conveyor is connected to the bottom of the pulverizing chamber to the finished product hopper.

[0008] As a further explanation of the technical solution: a pressure cylinder is connected to the filter box, a piston plate is slidably connected inside the pressure cylinder, a second hydraulic cylinder is installed on the piston plate, the second hydraulic cylinder is installed on the pressure cylinder, an air hole is opened on the pressure cylinder, and two pressure sensors are installed on the drying box.

[0009] As a further explanation of the technical solution: the filter plate adopts a multi-layer composite structure, consisting of an upper filter layer, a middle support layer, and a lower flow guiding layer; the filter layer is made of 316L stainless steel powder sintered at high temperature, with an average pore size controlled at 0.5-2μm and a porosity of 35%-45%, ensuring that it can both retain 1,4-dihydroxyanthraquinone solid particles (particle size usually greater than 5μm) and ensure the smooth passage of filtrate under an operating pressure of 0.3-0.6MPa; the middle support layer is woven from 50-100 mesh stainless steel wire mesh with a thickness of 2-3mm, which can withstand the weight of the filter cake and the operating pressure, preventing the filter layer from deforming due to pressure; the lower flow guiding layer is designed with a honeycomb structure with a honeycomb pore size of 5-8mm, used to quickly collect the filtrate passing through the filter layer, reducing flow resistance, and its bottom is connected to the filtrate collection chamber to achieve efficient filtrate discharge. The edges of the filter plates are sealed to the inner wall of the filter box with fluororubber sealing rings to ensure that the material will not leak from the side. The spacing between the filter plates is set to 15-20cm to facilitate the formation of filter cake and subsequent pushing operations.

[0010] As a further explanation of the technical solution: the pushing mechanism includes a push plate that can move horizontally, a scraper is installed at the lower edge of the push plate, the scraper is made of rubber, two first guide rods are connected to the left side of the push plate, the first guide rods pass through and slide inside the filter box, and a first hydraulic cylinder is connected to the left side of the push plate, the first hydraulic cylinder is installed on the left side of the filter box.

[0011] As a further explanation of the technical solution: the drying oven is provided with a support plate; the support plate has connecting holes; the support plate is equipped with extension strips; guide plates installed on the inner wall of the drying oven are connected to both sides of the support plate; the heating frame is serpentine; the position of the interval notch of the heating frame corresponds to the position of the connecting holes; the position of the solid part of the heating frame corresponds to the position of the extension strips.

[0012] As a further explanation of the technical solution: photoelectric sensors are installed on both the upper and lower sides of the heating frame, and a pressure control valve is installed outside the connecting pipe.

[0013] As a further explanation of the technical solution: two adjacent connecting holes are staggered and inclined towards the side wall of the heating frame, with an inclination angle of 3-8°.

[0014] As a further explanation of the technical solution: a first horizontal plate and a second horizontal plate are installed inside the heating frame. A gap is left between the first horizontal plate and the front end face of the inner wall of the heating frame, and a gap is left between the second horizontal plate and the rear end face of the inner wall of the heating frame. The first horizontal plate and the second horizontal plate are interlaced. An oil outlet pipe and an oil inlet pipe are respectively connected to the upper and lower sides of the two end faces of the heating frame.

[0015] As a further explanation of the technical solution: the material guiding mechanism includes an inclined plate slidably connected to the back of the drying chamber, a threaded seat installed under the inclined plate, a lead screw threadedly connected to the threaded seat, a first drive motor fixedly connected to the end of the lead screw, the first drive motor being installed on the back of the drying chamber, two sliding seats installed under the inclined plate, a second guide rod slidably connected to the sliding seats, and the second guide rod being installed on the back of the drying chamber.

[0016] The beneficial effects of this invention are as follows: 1. In this invention, the continuous filtration and drying process integrates filtration, drying, and pulverization into a single unit, enabling continuous production of 1,4-dihydroxyanthraquinone from reactants to finished products. The multi-layer sintered metal filter plate design ensures efficient solid-liquid separation, while precise control of operating pressure and filter cake thickness lays a solid foundation for subsequent drying processes. During drying, the synergistic effect of heating frame heating and nitrogen purging, combined with a vacuum environment and nitrogen purging agitation, effectively improves drying efficiency and uniformity, shortens drying time, and ensures controllable particle size of the pulverized material. Furthermore, the entire process is conducted in a closed environment, and the use of 316L stainless steel maximizes product purity and quality, reduces manual intervention, and improves production efficiency, making it suitable for large-scale continuous industrial production.

[0017] 2. In this invention, during the filtration stage, the method continuously pumps the reactant material containing 1,4-dihydroxyanthraquinone into the filter box via a delivery pump, allowing it to flow from top to bottom through multiple horizontally arranged metal sintered filter plates. Simultaneously, the controller drives the second hydraulic cylinder to extend, causing the piston plate to move downward and compressing the gas above the filter plates to form a controllable positive pressure. This pressure is monitored in real time by a pressure sensor and adjusted to a set range before the hydraulic cylinder stops operating. Under the continuous pressure, the reactant material accelerates through the filter plates and quickly collects at the bottom of the filter box, thereby significantly improving the filtration speed and collection efficiency of the 1,4-dihydroxyanthraquinone-containing material and providing a stable and reliable material basis for subsequent processes.

[0018] 3. In this invention, during the filter cake drying stage, the controller starts the circulating pump, drawing nitrogen from the top of the drying chamber and reintroducing it from the bottom, forming an upward circulating airflow. This airflow passes through the support plate and its connecting holes, blowing the filter cake on the plate upward and distributing it evenly between the serpentine heating frames. Simultaneously, the pressure control valve adjusts the flow rate of the input gas at a fixed frequency, dynamically changing the purging force on the filter cake, thus allowing it to float up and down within the heating frame area. During this process, the filter cake is continuously heated, gradually removing moisture and reducing its weight. When the nitrogen blows the filter cake higher than the heating frame range, the photoelectric sensor above detects a signal, and the controller immediately adjusts the pressure control valve to reduce the gas pressure, weakening the purging force and thus stabilizing the filter cake's floating range within the heating frame area. This method, through the synergistic effect of dynamic nitrogen purging and heat transfer oil heating, causes the filter cake to continuously tumble during the drying process, achieving efficient and uniform heating and drying, effectively shortening the drying time, and improving overall process efficiency and product quality stability. Attached Figure Description

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a three-dimensional cross-sectional structural diagram of the present invention; Figure 3 This is a rear-view stereoscopic structural schematic diagram of the present invention; Figure 4 This is a three-dimensional structural diagram of the material guiding mechanism in this invention; Figure 5 This is a frontal cross-sectional view of the present invention; Figure 6 This is the present invention. Figure 5 Enlarged structural diagram of section A; Figure 7 This is the present invention. Figure 5 Enlarged structural diagram of section B; Figure 8 This is a schematic diagram of the three-dimensional cross-sectional structure of the heating frame in this invention; Figure 9 This is a schematic diagram of the three-dimensional cross-sectional structure of the support plate in this invention; Figure 10 This is a schematic diagram of the three-dimensional separation structure of the filter plate in this invention; In the diagram: 1. Filter box; 2. Feed pipe; 3. Conveyor pump; 4. Solenoid valve; 5. Filter plate; 6. Push plate; 7. First guide rod; 8. First hydraulic cylinder; 9. Pressure cylinder; 10. Piston plate; 11. Second hydraulic cylinder; 12. Air port; 13. Pressure sensor; 14. First partition; 15. Third hydraulic cylinder; 16. First support; 17. Drying oven; 18. Second partition; 19. Fourth hydraulic cylinder; 20. Second support; 21. Vacuum pump; 22. Heating frame; 23. First horizontal plate; 24. Second horizontal plate; 25. Support plate; 26. Extension strip; 27. Connecting hole 28. Guide plate; 29. ​​Support leg; 30. Material guiding mechanism; 301. Inclined plate; 302. Threaded seat; 303. Lead screw; 304. First drive motor; 305. Sliding seat; 306. Second guide rod; 31. Circulating pump; 32. Connecting pipe; 33. Pressure control valve; 34. Air supply head; 35. Discharge channel; 36. Third partition; 37. Fifth hydraulic cylinder; 38. Third bracket; 39. Crushing cylinder; 40. Second drive motor; 41. Rotating shaft; 42. Crushing blade; 43. Screen; 44. Photoelectric sensor; 45. Connecting channel; 46. Heater. Detailed Implementation

[0021] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0022] like Figures 1 to 10 As shown, a continuous filtration and drying method for 1,4-dihydroxyanthraquinone includes the following steps: Step 1: The reactant containing 1,4-dihydroxyanthraquinone is continuously fed into the filtration area of ​​the integrated filtration and drying device through a pump 3. The filtration area is equipped with multi-layer metal sintered filter plates 5 with a pore size of 0.5-2μm. The material is pressurized and filtered under an operating pressure of 0.3-0.6MPa. The filter cake thickness is controlled at 3-8cm. The filtrate is collected by the filter plates 5 and continuously discharged from the filtrate outlet, thus achieving preliminary solid-liquid separation. Step 2: After filtration, the filter cake is pushed to the drying area by the built-in filter cake pushing mechanism. The drying area uses a combination of heating frame 22 and nitrogen purging. Heat transfer oil at 120-150℃ is introduced into the heating frame 22, and nitrogen gas preheated to 80-100℃ is introduced from the bottom of the drying area at a flow rate of 0.5-1.2 m³ / h. The filter cake is vacuum dried under a vacuum degree of -0.08 to -0.095 MPa for 2-4 hours. During the drying process, the filter cake is turned over by nitrogen purging to ensure uniform drying. Step 3: The dried 1,4-dihydroxyanthraquinone solid is pulverized to a particle size of 50-150 mesh by a pulverizing device, and then conveyed to the finished product silo by a screw conveyor. Throughout the process, the equipment is kept under a slight positive pressure to prevent external impurities from entering, and all parts in contact with the material are made of 316L stainless steel to avoid material contamination.

[0023] This continuous filtration and drying method integrates filtration, drying, and pulverization processes into a single unit, enabling continuous production of 1,4-dihydroxyanthraquinone from reactants to finished product. The multi-layer sintered metal filter plate 5 ensures efficient solid-liquid separation, while precise control of operating pressure and filter cake thickness lays a solid foundation for subsequent drying processes. During drying, the synergistic effect of heating frame 22 and nitrogen purging, combined with a vacuum environment and nitrogen purging agitation, effectively improves drying efficiency and uniformity, and shortens drying time. The particle size of the pulverized material is controllable, and the entire process is conducted in a closed environment. The use of 316L stainless steel maximizes product purity and quality, reduces manual intervention, and improves production efficiency, making it suitable for large-scale continuous industrial production.

[0024] A continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone includes a filtration unit, a drying unit, and a pulverizing unit connected in sequence. The filtration unit and the drying unit are seamlessly connected via a connecting channel 45, and the drying unit and the pulverizing unit are seamlessly connected via a feeding channel 35. The filtration unit includes a filter box 1, with a feed pipe 2 connected to the left side of the filter box 1. A solenoid valve 4 is installed outside the feed pipe 2, and a conveying pump 3 is connected to the end of the feed pipe 2. Filter plates 5 are horizontally arranged inside the filter box 1, and a filter plate that can move horizontally is also provided inside the filter box 1. The push mechanism for directional movement has a first partition 14 vertically slidably connected to the right side wall of the filter box 1. A third hydraulic cylinder 15 is connected to the first partition 14 and is mounted on the filter box 1 via a first bracket 16. A filtrate collection chamber is provided below the filter plate 5, and the bottom of the collection chamber is connected to the filtrate outlet. The drying device includes a drying box 17, with a support leg 29 installed below it. A heating frame 22 is provided on the inner wall of the drying box 17. A circulation pump 31 is connected to the drying box 17, and the air inlet of the circulation pump 31 is connected to the drying box 17. The outlet of pump 31 is connected to a connecting pipe 32. A heater 46 is installed outside the connecting pipe 32. An air supply head 34 is installed above the heater 46 outside the connecting pipe 32. The bottom end of the connecting pipe 32 is connected to the drying chamber 17. A vacuum pump 21 is connected to the top of the drying chamber 17. A material guiding mechanism 30 is provided on the back of the drying chamber 17. A second partition 18 is slidably connected inside the connecting channel 45. A fourth hydraulic cylinder 19 is connected to the second partition 18. The fourth hydraulic cylinder 19 is mounted on the connecting channel 45 via a second bracket 20. The right side of the drying chamber 17... A third partition 36 is slidably connected to the inner side wall, and a fifth hydraulic cylinder 37 is connected to the third partition 36. The fifth hydraulic cylinder 37 is mounted on the drying chamber 17 via a third bracket 38. The crushing device includes a crushing chamber 39, on which a second drive motor 40 is installed. The output shaft of the second drive motor 40 is connected to a rotating shaft 41. A crushing blade 42 is installed outside the rotating shaft 41. A screen 43 is provided below the crushing blade 42. The screen 43 has a mesh size corresponding to a particle size requirement of 50-150 mesh. A screw conveyor is connected to the bottom of the crushing chamber 39 to lead to the finished product silo.

[0025] The reactants containing 1,4-dihydroxyanthraquinone are continuously pumped into the filter box 1 from the feed pipe 2 via the delivery pump 3. The reactants then pass from top to bottom through at least three horizontally arranged parallel metal sintered filter plates 5 (the pore size of the filter plates 5 is 0.5-2 μm). During this process, the liquid passes through the filter plates 5 and enters the corresponding filtrate collection chamber below, and is continuously discharged from the filtrate outlet at the bottom of the collection chamber, achieving preliminary solid-liquid separation. The thickness of the resulting filter cake is controlled at 3-8 cm. After filtration is complete, the controller controls the first hydraulic cylinder 8 and the fourth hydraulic cylinder 19 to shorten. The first hydraulic cylinder 8 moves the first partition 14 upwards to above the connecting channel 45, and the fourth hydraulic cylinder 19 moves the second partition 18 upwards to above the connecting channel 45. Then, the controller controls the pushing mechanism (which can move horizontally) to start, precisely docking with the outlet end of the filter plate 5 of the filter device, and smoothly pushing the filter cake into the drying mold device. After entering the drying unit, the controller controls the extension of the first hydraulic cylinder 8 and the fourth hydraulic cylinder 19. The first hydraulic cylinder 8 moves the first partition 14 downward to its limit position, and the fourth hydraulic cylinder 19 moves the second partition 18 upward to its limit position. Then, the controller controls the heating frame 22 to start working. Heat transfer oil at 120-150℃ is introduced into the heating frame 22 for heating. At the same time, nitrogen gas is introduced into the heater 46 through the gas supply head 34. After being preheated to 80-100℃ by the heater 46, it enters the drying chamber 17 through the connecting pipe 32, and then the controller controls the extension of the first hydraulic cylinder 19. The vacuum pump 21 is started to maintain a vacuum level of -0.08 to -0.095 MPa inside the drying chamber 17. Then, the circulation pump 31 is started to draw nitrogen from the top of the drying chamber 17 and introduce it from the bottom, allowing the nitrogen to circulate from bottom to top inside the drying chamber 17. The filter cake is slowly turned over and vacuum-heated and dried under the upward flow of nitrogen. The drying time is controlled at 2-4 hours. The dried 1,4-dihydroxyanthraquinone solid is conveyed from the discharge port of the drying device to the inlet of the pulverizing device through the material guiding mechanism 30. Inside the pulverizing device, the high-speed rotating pulverizing blades 42 pulverize the material. The pulverized material is screened through the grading screen 43 below, which corresponds to the particle size requirement of 50-150 mesh. The material that meets the particle size requirement falls to the bottom of the pulverizing device and is conveyed to the finished product silo by the screw conveyor at the bottom of the pulverizing device. Throughout the entire operation, the equipment maintains a slight positive pressure inside. All parts that come into contact with the materials are made of 316L stainless steel. The various devices are seamlessly connected through material channels with sealed doors, effectively preventing external impurities from entering and ensuring product purity.

[0026] The device adopts a frame structure. The shells of each functional device and the push plates 6 and crushing chambers that come into contact with materials are all precision machined from 316L stainless steel. The device also maintains a slightly positive pressure environment through a pressure control system to ensure the airtightness and safety of the production process.

[0027] like Figure 2 As shown, a pressure cylinder 9 is connected to the filter box 1, and a piston plate 10 is slidably connected inside the pressure cylinder 9. A second hydraulic cylinder 11 is installed on the piston plate 10. The second hydraulic cylinder 11 is installed on the pressure cylinder 9. An air hole 12 is opened on the pressure cylinder 9. Two pressure sensors 13 are installed on the drying box 17.

[0028] The reactant material containing 1,4-dihydroxyanthraquinone is continuously pumped into the filter box 1 from the feed pipe 2 via the delivery pump 3. It passes from top to bottom through at least three horizontally arranged parallel metal sintered filter plates 5 inside the filter device. Simultaneously, the controller controls the extension of the second hydraulic cylinder 11, which drives the piston plate 10 downwards. This downward movement compresses the gas, increasing the pressure in the space above the filter plates 5. The pressure sensor 13 detects the pressure value inside the filter box 1 and adjusts it to a specified range. The controller then stops the second hydraulic cylinder 11, allowing the air pressure to act on the reactant material on the filter plates 5 from top to bottom. This allows the reactant material to quickly pass through the filter plates 5 and fall to the bottom of the filter box 1, ensuring rapid filtration of the reactant material containing 1,4-dihydroxyanthraquinone and guaranteeing efficient filtration and collection.

[0029] like Figure 10 As shown, filter plate 5 adopts a multi-layer composite structure, consisting of an upper filter layer, a middle support layer, and a lower flow guiding layer. The filter layer is made of 316L stainless steel powder sintered at high temperature, with an average pore size controlled at 0.5-2μm and a porosity of 35%-45%. This ensures that under an operating pressure of 0.3-0.6MPa, it can both retain 1,4-dihydroxyanthraquinone solid particles (typically larger than 5μm) and guarantee the smooth passage of filtrate. The middle support layer is woven from 50-100 mesh stainless steel wire mesh with a thickness of 2-3mm. It can withstand the weight of the filter cake and the operating pressure, preventing the filter layer from deforming under pressure. The lower flow guiding layer is designed with a honeycomb structure with a honeycomb pore size of 5-8mm. It is used to quickly collect the filtrate passing through the filter layer, reducing flow resistance. Its bottom is connected to the filtrate collection chamber, realizing efficient discharge of filtrate. The edges of the filter plates 5 are sealed to the inner wall of the filter box 1 by fluororubber sealing rings to ensure that the material will not leak from the side. The spacing between the filter plates 5 is set to 15-20cm to facilitate the formation of filter cake and subsequent pushing operations.

[0030] The reactant material containing 1,4-dihydroxyanthraquinone on filter plate 5 first contacts the upper filter layer. This filter layer is made of 316L stainless steel powder sintered at high temperature, with an average pore size precisely controlled between 0.5-2μm. This pore size design effectively traps 1,4-dihydroxyanthraquinone solid particles in the reactant material, which typically have a particle size greater than 5μm, while ensuring that the filtrate can smoothly pass through the filter layer. Its 35%-45% porosity provides a guarantee for high-efficiency filtration. The middle support layer below the filter layer is woven from 50-100 mesh stainless steel wire mesh, with a thickness of 2-3mm. It acts like a sturdy skeleton, steadily bearing the weight of the filter cake above and the operating pressure, effectively preventing the filter layer from collapsing under pressure. Deformation occurs under force, ensuring stable filtration. The filtrate passing through the filter layer then enters the lower guide layer, which is designed with a honeycomb structure with a pore size of 5-8mm. This special structure greatly increases the flow area of ​​the filtrate, enabling it to quickly collect the filtrate that has passed through the filter layer. This significantly reduces the flow resistance of the filtrate during the discharge process, allowing it to quickly flow to the bottom and enter the connected filtrate collection chamber, ultimately achieving efficient discharge of the filtrate. The edge of filter plate 5 is tightly sealed to the inner wall of the equipment through a fluororubber sealing ring. This detailed design ensures that materials will not leak from the side of filter plate 5 during filtration, guaranteeing the effect of solid-liquid separation and the cleanliness of the operating environment.

[0031] like Figure 2 and Figures 5 to 6 As shown, the pushing mechanism includes a push plate 6 that can move horizontally. A scraper is installed at the lower edge of the push plate 6. The scraper is made of rubber. Two first guide rods 7 are connected to the left side of the push plate 6. The first guide rods 7 pass through and slide inside the filter box 1. A first hydraulic cylinder 8 is connected to the left side of the push plate 6. The first hydraulic cylinder 8 is installed on the left side of the filter box 1.

[0032] The size of the pusher plate 6 matches the horizontal projected area of ​​the filter plate 5. The first hydraulic cylinder 8 is controlled by the controller. When the first hydraulic cylinder 8 extends, the moving speed of the pusher plate 6 can be precisely controlled to 0.1-0.3m / s, ensuring that the filter cake is pushed smoothly and without damage into the drying chamber 17. The scraper is made of fluororubber with a Shore hardness of 70-80 degrees, which not only ensures good sealing with the surface of the filter plate 5 and prevents material residue, but also avoids scratching the metal sintered filter plate 5 during long-term use due to its good wear resistance and flexibility, thus protecting the filtration performance and service life of the filter plate 5. The scraper and the pusher plate 6 are detachably connected, which is convenient for replacement after wear.

[0033] like Figure 2As shown, a support plate 25 is provided inside the drying oven 17; a connection hole 27 is provided on the support plate 25; an extension strip 26 is installed on the support plate 25; guide plates 28 installed on the inner wall of the drying oven 17 are connected to both the left and right sides of the support plate 25; the heating frame 22 is designed in a serpentine shape, and the solid part of the heating frame 22 corresponds to the position of the extension strip 26.

[0034] When the filter cake enters the drying chamber 17 for drying, the controller controls the heating frame 22 to start working. Heat transfer oil at 120-150℃ is introduced into the heating frame 22 for heating. At the same time, nitrogen gas is introduced into the heater 46 through the gas supply head 34. After being preheated to 80-100℃ by the heater 46, it enters the drying chamber 17 through the connecting pipe 32. Then, the controller controls the vacuum pump 21 to start, so that the vacuum degree in the drying chamber 17 is maintained at -0.08 to -0.095MPa. The filter cake is slowly turned and enters the space between the serpentine heating frames 22 under the upward flow of nitrogen, so that the filter cake is in the interval part of the heating frame 22. The heat transfer oil in the serpentine heating frame 22 heats the filter cake. Under the synergistic effect of the upward blowing of preheated nitrogen and the heating of the heating frame 22, the filter cake is constantly turned and evenly heated, thereby significantly improving the heating and drying efficiency and realizing the high-efficiency operation of the entire filtration and drying process.

[0035] like Figures 1-2 As shown, photoelectric sensors 44 are installed on both the upper and lower sides of the heating frame 22, and a pressure control valve 33 is installed on the outside of the connecting pipe 32.

[0036] During filter cake drying, the circulation pump 31 is controlled by the controller to operate. The circulation pump 31 draws nitrogen from the top of the drying chamber 17 and introduces it from the bottom of the drying chamber 17, causing the nitrogen to circulate from bottom to top within the drying chamber 17. At this time, the nitrogen flows upward through the support plate 25 and the connecting hole 27, thereby blowing the filter cake on the support plate 25 upward, causing the filter cake to float into the serpentine heating frame 22. The pressure control valve 33 controls the amount of gas introduced into the drying chamber 17 through the connecting pipe 32 to vary at a fixed frequency, thereby continuously changing the purging force on the filter cake within the heating frame 22, thus causing the filter cake to undergo [further drying / drying]. The filter cake floats up and down, allowing the nitrogen purging and heating frame 22 to work together to turn and heat the filter cake. As the filter cake continues to heat, the moisture content inside the filter cake gradually decreases, thus reducing the weight of the filter cake. At this point, the nitrogen blows the filter cake upwards beyond the height of the heating frame 22. The photoelectric sensor 44 on the upper side detects that the filter cake has exceeded the height of the heating frame 22, and the controller controls the pressure range of the pressure control valve 33 to decrease, thereby reducing the purging force of the blown nitrogen on the filter cake. This keeps the up-and-down floating range of the filter cake within the area of ​​the heating frame 22, ensuring that the filter cake remains within the area of ​​the heating frame 22 throughout the drying process, thus ensuring the drying efficiency of the filter cake.

[0037] like Figure 9As shown, two adjacent connecting holes 27 are staggered and inclined toward the side wall of the heating frame 22 at an angle of 3-8°.

[0038] When drying the filter cake, the circulation pump 31 is controlled by the controller to operate. At this time, the circulation pump 31 draws nitrogen from the top of the drying chamber 17 and discharges it, and introduces it from the bottom of the drying chamber 17, so that the nitrogen circulates from bottom to top in the drying chamber 17. At this time, the nitrogen flows upward through the support plate 25 and the connecting hole 27. When the nitrogen flows upward along the inclined connecting hole 27, it blows the filter cake up and hits it obliquely on the side wall of the heating frame 22, thereby avoiding the filter cake from hitting the lower surface of the heating frame 22 when it is blown up. This allows the filter cake to be smoothly blown into the area between the heating frames 22. This design effectively avoids the filter cake from directly hitting the lower surface of the heating frame 22 when it is blown up vertically, and guides the filter cake smoothly into the area between the heating frames 22, thereby ensuring the efficient heating and drying of the filter cake by the heating frame 22.

[0039] like Figure 2 and Figure 8 As shown, a first horizontal plate 23 and a second horizontal plate 24 are installed inside the heating frame 22. A gap is left between the first horizontal plate 23 and the front end face of the inner wall of the heating frame 22, and a gap is left between the second horizontal plate 24 and the rear end face of the inner wall of the heating frame 22. The first horizontal plate 23 and the second horizontal plate 24 are interlaced. An oil outlet pipe and an oil inlet pipe are respectively connected to the upper and lower sides of the two end faces of the heating frame 22.

[0040] The first horizontal plate 23 and the second horizontal plate 24 divide the internal space of the heating frame 22 into a continuous serpentine channel. When the filter cake is heated and dried in the heating chamber, heat transfer oil at 120-150℃ is introduced into the heating frame 22 through the oil inlet pipe. The heat transfer oil gradually fills the heating frame 22 from the bottom through the serpentine channel, and finally flows out through the oil outlet pipe. Combined with nitrogen gas introduced from bottom to top, the nitrogen gas blows the filter cake to float between the heating frames 22. The pressure control valve 33 controls the amount of gas introduced into the drying chamber 17 through the connecting pipe 32 to change at a fixed frequency, so that the blowing force on the filter cake in the heating frame 22 changes continuously, and the filter cake floats up and down in the heating frame 22. When the filter cake is at the same horizontal level in the area of ​​the heating frame 22, and the heating... The heat field distribution on the surface of frame 22 is highly uniform, ensuring consistent heating of all material particles on the same layer and guaranteeing uniform drying in the horizontal direction. Furthermore, as the filter cake floats up and down, the particles repeatedly pass through the vertical temperature gradient region formed by the structure of heating frame 22 and the hot airflow. This dynamic movement effectively breaks the static boundary layer on the material surface, allowing heat to quickly penetrate into the filter cake. This not only accelerates the moisture evaporation rate but also ensures balanced heating of the filter cake in the thickness direction, thus achieving efficient and uniform drying in the vertical direction. The synergistic effect of horizontal suspension heating and vertical tumbling gradient greatly improves the uniformity and efficiency of filter cake drying, thereby significantly increasing the overall production efficiency of 1,4-dihydroxyanthraquinone.

[0041] like Figure 2 and Figure 4 As shown, the material guiding mechanism 30 includes an inclined plate 301 slidably connected to the back of the drying chamber 17. A threaded seat 302 is installed under the inclined plate 301. A lead screw 303 is threadedly connected to the threaded seat 302. A first drive motor 304 is fixedly connected to the end of the lead screw 303. The first drive motor 304 is installed on the back of the drying chamber 17. Two sliding seats 305 are installed under the inclined plate 301. A second guide rod 306 is slidably connected to the sliding seat 305. The second guide rod 306 is installed on the back of the drying chamber 17.

[0042] After the filter cake is dried by the drying device, the first drive motor 304 is first controlled by the controller to run. At this time, the first drive motor 304 drives the lead screw 303 to rotate, thereby causing the lead screw 303 to move the threaded seat 302 and the inclined plate 301 forward. At the same time, the circulating pump 31 continuously controls the nitrogen to flow upward on the drying chamber 17. At this time, the nitrogen carries the dried filter cake and gradually accumulates on the inclined plate 301 that extends into the drying chamber 17 until the inclined plate 301 moves to fit against the inner wall of the drying chamber 17. At this time, the circulating pump 31 and the first drive motor 304 are stopped. Then, the fifth hydraulic cylinder 37 is controlled by the controller to shorten. At this time, the fifth hydraulic cylinder 37 drives the third partition 36 to move upward until it passes the lower part of the chamber. The filter cake on the surface of the inclined plate 301 slides down the feed channel 35 under gravity and enters the crushing device. At this time, the controller controls the second drive motor 40 to work. The second drive motor 40 drives the crushing blade 42 to crush the material. The crushed material is screened by the grading screen 43 below, which corresponds to the particle size requirement of 50-150 mesh. The material that meets the particle size requirement falls to the bottom of the crushing device and is transported to the finished product silo by the screw conveyor at the bottom of the crushing device. This completes the continuous and automated production process of raw materials from drying and closed discharge to fine crushing and grading collection, effectively avoiding secondary pollution of materials during the transfer process and ensuring the uniformity and quality of the final product particle size.

[0043] During operation, the reactants containing 1,4-dihydroxyanthraquinone are continuously pumped into the filter box 1 from the feed pipe 2 via the delivery pump 3. The reactants then pass from top to bottom through at least three horizontally arranged parallel metal sintered filter plates 5 (filter plate 5 pore size 0.5-2μm) inside the filter device. During this process, the liquid passes through the filter plates 5 into the corresponding filtrate collection chamber below and is continuously discharged from the filtrate outlet at the bottom of the collection chamber, achieving preliminary solid-liquid separation. The thickness of the resulting filter cake is controlled at 3-8cm. After filtration is complete, the controller controls the first hydraulic cylinder 8 and the fourth hydraulic cylinder 19 to shorten. The first hydraulic cylinder 8 moves the first partition 14 upwards to above the connecting channel 45, and the fourth hydraulic cylinder 19 moves the second partition 18 upwards to above the connecting channel 45. Then, the controller controls the pushing... The mechanism (which can move horizontally) is activated and precisely docks with the outlet end of the filter plate 5 of the filter device, smoothly pushing the filter cake into the drying mold device. After entering the drying device, the controller controls the extension of the first hydraulic cylinder 8 and the fourth hydraulic cylinder 19. The first hydraulic cylinder 8 drives the first partition 14 to move downward to the limit position, and the fourth hydraulic cylinder 19 drives the second partition 18 to move upward to the limit position. Then, the controller controls the heating frame 22 to start working. Heat transfer oil at 120-150℃ is introduced into the heating frame 22 for heating. At the same time, nitrogen gas is introduced into the heater 46 from the gas supply head 34. After being preheated to 80-100℃ by the heater 46, it enters the drying chamber 17 through the connecting pipe 32. Then, the controller controls the vacuum pump 21 to start, so that the temperature inside the drying chamber 17 is maintained at -0.08 to -0℃.A vacuum of 0.95 MPa is established, and then the circulation pump 31 is controlled to operate. The circulation pump 31 draws nitrogen from the top of the drying chamber 17 and discharges it, while introducing it from the bottom of the drying chamber 17, causing the nitrogen to circulate from bottom to top within the drying chamber 17. The filter cake is slowly turned over and vacuum-heated and dried under the upward flow of nitrogen. The drying time is controlled to be 2-4 hours. After the filter cake is dried, the controller first controls the first drive motor 304 to run. At this time, the first drive motor 304 drives the lead screw 303 to rotate, thereby causing the lead screw 303 to move the threaded seat 302 and the inclined plate 301 forward. At the same time, the circulation pump 31 continuously controls the upward flow of nitrogen on the drying chamber 17. At this time, the nitrogen carrying the dried filter cake gradually accumulates on the inclined plate 301 that extends into the drying chamber 17, until the inclined plate 301 moves to the position of the drying chamber 17. The inner wall of box 17 is closed. At this time, the circulating pump 31 and the first drive motor 304 stop working. Then, the controller controls the fifth hydraulic cylinder 37 to shorten. At this time, the fifth hydraulic cylinder 37 drives the third partition 36 to move upward until it passes over the feeding channel 35. The filter cake on the surface of the inclined plate 301 slides down by gravity and passes through the feeding channel 35 into the crushing device. At this time, the controller controls the fifth hydraulic cylinder 37 to extend. The fifth hydraulic cylinder 37 drives the third partition 36 downward to close the feeding channel 35. Inside the crushing device, the second drive motor 40 drives the crushing blade 42 to crush the material. The crushed material is screened by the grading screen 43 below, which corresponds to the particle size requirement of 50-150 mesh. The material that meets the particle size requirement falls to the bottom of the crushing device and is transported to the finished product silo by the screw conveyor at the bottom of the crushing device.

[0044] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A continuous filtration and drying method for 1,4-dihydroxyanthraquinone, characterized in that, Includes the following steps: Step 1: The reactant containing 1,4-dihydroxyanthraquinone is continuously fed into the filtration area of ​​the integrated filtration and drying device through a pump (3). The filtration area is equipped with a filter plate (5) with a pore size of 0.5-2μm. The material is pressurized and filtered under an operating pressure of 0.3-0.6MPa. The filter cake thickness is controlled at 3-8cm. The filtrate is collected by the filter plate (5) and continuously discharged from the filtrate outlet to achieve preliminary solid-liquid separation. Step 2: After filtration, the filter cake is pushed to the drying area by the built-in filter cake pushing mechanism of the equipment. The drying area adopts a combination of heating frame (22) heating and nitrogen purging. Heat transfer oil at 120-150℃ is introduced into the heating frame (22), and nitrogen gas preheated to 80-100℃ is introduced from the bottom of the drying area. The nitrogen gas flow rate is 0.5-1.2m³ / h, so that the filter cake is vacuum dried under the condition of vacuum degree of -0.08 to -0.095MPa. The drying time is controlled at 2-4 hours. Step 3: The dried 1,4-dihydroxyanthraquinone solid is crushed to a particle size of 50-150 mesh by a crushing device, and then conveyed to the finished product silo by a screw conveyor.

2. A continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone, applicable to the filtration and drying method described in claim 1, characterized in that: The filtration and drying device includes a filtration device, a drying device, and a pulverizing device connected in sequence; the filtration device and the drying device are seamlessly connected through a connecting channel (45); the drying device and the pulverizing device are seamlessly connected through a feeding channel (35); the filtration device includes a filter box (1); a feed pipe (2) is connected to the left side of the filter box (1); a solenoid valve (4) is provided outside the feed pipe (2); a conveying pump (3) is connected to the end of the feed pipe (2); a filter plate (5) is horizontally arranged inside the filter box (1); a pushing mechanism that can move horizontally is configured inside the filter box (1); the filter box (1) A first partition (14) is vertically slidably connected to the inside of the right side wall; a third hydraulic cylinder (15) is connected to the first partition (14); the third hydraulic cylinder (15) is mounted on the filter box (1) via a first bracket (16); a filtrate collection chamber is provided below the filter plate (5); the bottom of the collection chamber is connected to the filtrate outlet; the drying device includes a drying box (17); a support leg (29) is installed under the drying box (17); a heating frame (22) is provided on the inner wall of the drying box (17); a circulation pump (31) is connected to the drying box (17); the air inlet of the circulation pump (31) is connected to the drying box (17); the circulation pump (31) A connecting pipe (32) is connected to the air outlet; a heater (46) is installed outside the connecting pipe (32); an air supply head (34) is installed above the heater (46) outside the connecting pipe (32); the bottom end of the connecting pipe (32) is connected to the drying box (17); a vacuum pump (21) is connected to the top of the drying box (17); a material guiding mechanism (30) is provided on the back of the drying box (17); a second partition (18) is slidably connected inside the connecting channel (45); a fourth hydraulic cylinder (19) is connected to the second partition (18); the fourth hydraulic cylinder (19) is installed in the connecting channel (45) via a second bracket (20). 5) The drying chamber (17) is slidably connected to the right side wall of the drying chamber (17); a fifth hydraulic cylinder (37) is connected to the third partition (36); the fifth hydraulic cylinder (37) is mounted on the drying chamber (17) via a third bracket (38); the crushing device includes a crushing chamber (39); a second drive motor (40) is installed on the crushing chamber (39); the output shaft of the second drive motor (40) is connected to a rotating shaft (41); a crushing blade (42) is installed outside the rotating shaft (41); a screen (43) is provided below the crushing blade (42); a screw conveyor is connected to the bottom of the crushing chamber (39) to lead to the finished product silo.

3. The continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone according to claim 2, characterized in that: The filter box (1) is connected to a pressure cylinder (9); a piston plate (10) is slidably connected inside the pressure cylinder (9); a second hydraulic cylinder (11) is installed on the piston plate (10); the second hydraulic cylinder (11) is installed on the pressure cylinder (9); an air hole (12) is opened on the pressure cylinder (9); two pressure sensors (13) are installed on the drying box (17).

4. The continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone according to claim 3, characterized in that: The filter plate (5) adopts a multi-layer composite structure; it consists of an upper filter layer, a middle support layer and a lower flow guide layer; the filter layer is made of 316L stainless steel powder sintered at high temperature; the middle support layer is woven from 50-100 mesh stainless steel wire mesh; the lower flow guide layer is designed as a honeycomb structure; the edge of the filter plate (5) is sealed to the inner wall of the filter box (1) by a fluororubber sealing ring.

5. The continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone according to claim 4, characterized in that: The pushing mechanism includes a push plate (6) that can move horizontally; a scraper is installed at the lower edge of the push plate (6); the scraper is made of rubber; two first guide rods (7) are connected to the left side of the push plate (6); the first guide rods (7) pass through and slide inside the filter box (1); a first hydraulic cylinder (8) is connected to the left side of the push plate (6); the first hydraulic cylinder (8) is installed on the left side of the filter box (1).

6. The continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone according to claim 5, characterized in that: The drying oven (17) is provided with a support plate (25); the support plate (25) is provided with a connection hole (27); an extension strip (26) is installed on the support plate (25); guide plates (28) installed on the inner wall of the drying oven (17) are connected to both the left and right sides of the support plate (25); the heating frame (22) is designed in a serpentine shape; the position of the interval notch of the heating frame (22) corresponds to the position of the connection hole (27); the solid part of the heating frame (22) corresponds to the position of the extension strip (26).

7. The continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone according to claim 6, characterized in that: Photoelectric sensors (44) are installed on both the upper and lower sides of the heating frame (22); a pressure control valve (33) is installed on the outside of the connecting pipe (32).

8. The continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone according to claim 7, characterized in that: The two adjacent connecting holes (27) are staggered and inclined toward the side wall of the heating frame (22); the inclination angle is 3-8°.

9. A continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone according to claim 8, characterized in that: The heating frame (22) is equipped with a first horizontal plate (23) and a second horizontal plate (24); a gap is left between the first horizontal plate (23) and the front end face of the inner wall of the heating frame (22); a gap is left between the second horizontal plate (24) and the rear end face of the inner wall of the heating frame (22); the first horizontal plate (23) and the second horizontal plate (24) are interlocked; an oil outlet pipe and an oil inlet pipe are respectively connected to the upper and lower sides of the two end faces of the heating frame (22).

10. A continuous filtration and drying apparatus for 1,4-dihydroxyanthraquinone according to claim 9, characterized in that: The material guiding mechanism (30) includes an inclined plate (301) slidably connected to the back of the drying chamber (17); a threaded seat (302) is installed under the inclined plate (301); a lead screw (303) is threadedly connected to the threaded seat (302); a first drive motor (304) is fixedly connected to the end of the lead screw (303); the first drive motor (304) is installed on the back of the drying chamber (17); two sliding seats (305) are installed under the inclined plate (301); a second guide rod (306) is slidably connected to the sliding seat (305); the second guide rod (306) is installed on the back of the drying chamber (17).

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