A mixed methylnaphthalene precision rectification separation and purification device

Abstract

The application discloses a mixed methylnaphthalene precision rectification separation and purification device, and belongs to the technical field of coal chemical industry and fine chemical industry. The device comprises a rectification tower body, a spraying disc located at the top of the rectification tower body, and a steam inlet pipe arranged in the sidewall of the bottom of the rectification tower body. A plurality of layers of sieve trays are sequentially arranged in the rectification tower body from top to bottom, and adjacent two layers of the sieve trays are connected and communicated through downcomers. The first scraper with a V-shaped structure is arranged at the top of each layer of the sieve trays, and is matched with a swing mechanism composed of an arc-shaped cover plate, a rotating shaft, a leaf plate, a transmission bin and a multi-stage bevel gear. The impact force of liquid flowing from the downcomers is used as a power source to drive the first scraper to stably reciprocate and scrape on the top of the tray, so that the device does not need external power driving when in use, can adapt to the environment in the rectification tower, avoids the risk of vacuum degree damage caused by dynamic seal failure, and reduces equipment energy consumption and maintenance cost.

Description

Technical Field

[0001] This invention relates to a separation and purification apparatus, and more particularly to a precision distillation separation and purification apparatus for mixed methylnaphthalene, belonging to the fields of coal chemical and fine chemical technology. Background Technology

[0002] Currently, the separation and purification of mixed methylnaphthalene typically employs precision distillation technology. High-purity α-methylnaphthalene and β-methylnaphthalene products are obtained through vacuum distillation. However, in actual industrial production, the mixed methylnaphthalene feedstock inevitably contains a certain amount of unsaturated hydrocarbons, polycyclic aromatic hydrocarbons, and heteroatom-containing compounds, which are highly reactive components. Under the high-temperature, long-term operating environment of the distillation column, these substances are prone to thermal polymerization and condensation reactions, generating high molecular polymers and coke-like substances. These coke deposits preferentially adhere to the top surface of the sieve trays and the edges of the sieve holes, gradually forming a dense coke layer. As the operating time increases, the coke layer thickens, leading to a significant decrease in the effective opening rate of the tray sieve holes. This obstructs the upward steam flow, causes a continuous increase in tray pressure drop, and reduces gas-liquid contact efficiency. Ultimately, this results in the purity of the products at the top and bottom of the column failing to meet standards, severely restricting the long-term stable operation of the unit.

[0003] While existing technologies include designs for online cleaning using mechanical scraping, these scraping mechanisms generally rely on independent electric drive systems, which are unsuitable for the environment of vacuum distillation towers. They also increase energy consumption and affect the stable operation of the equipment. Furthermore, the collection and cleaning of impurities is inconvenient.

[0004] To address this issue, a precision distillation and purification apparatus for mixed methylnaphthalene was designed to optimize the aforementioned problem. Summary of the Invention

[0005] The main objective of this invention is to provide a precision distillation and purification apparatus for mixed methylnaphthalene to solve the problems mentioned in the background art.

[0006] The objective of this invention can be achieved by adopting the following technical solution: A precision distillation separation and purification device for mixed methylnaphthalene includes a distillation column, a spray tray located at the top of the distillation column, and a steam inlet pipe opened on the bottom side wall of the distillation column. The interior of the distillation column is provided with multiple layers of screen trays from top to bottom, and adjacent layers of screen trays are connected by downcomers. Each layer of the screen tray is provided with a first scraper at the top, and the downcomer is provided with a swing mechanism inside. The first scraper is connected to the swing mechanism in a transmission manner. The swing mechanism is driven by the liquid flowing through the downcomer and is used to drive the first scraper to swing back and forth at the top of the screen tray. The bottom of the distillation column is provided with a collection and filtration mechanism, which includes a filter barrel. The inlet of the filter barrel is connected to the outlet of the bottom downcomer. A drain pipe is provided at the bottom of the filter barrel. A centrifugal drive assembly is provided at the outlet of the steam inlet pipe. The centrifugal drive assembly is connected to the filter barrel for driving the liquid in the filter barrel to perform centrifugal filtration.

[0007] Preferably, the first scraper has a V-shaped structure, and the bottom of the first scraper is in contact with the top surface of the screen tray.

[0008] The V-shaped structure can bidirectionally push and disturb the liquid layer during reciprocating oscillation, improving cleaning efficiency.

[0009] Preferably, the oscillating mechanism includes an arc-shaped cover plate fixedly installed on the inner wall of the downcomer, a rotating shaft rotatably installed inside the arc-shaped cover plate, a blade plate fixedly installed on the rotating shaft, the blade plate being positioned directly opposite the liquid falling direction of the downcomer, a transmission assembly being provided at the middle position of the arc-shaped cover plate, the input end of the transmission assembly being connected to the rotating shaft, and the output end of the transmission assembly being connected to the first scraper.

[0010] The falling liquid concentrates and impacts the blade area. After being impacted, the blade transmits power to the first scraper through the transmission assembly, enabling online cleaning of the tower tray without the need for external power drive.

[0011] Preferably, the transmission assembly includes a transmission chamber fixedly installed on the outer wall of the downcomer. One end of the rotating shaft extends into the transmission chamber and is fixedly installed with a first bevel gear. A connecting shaft is rotatably installed inside the transmission chamber. A second bevel gear and a third bevel gear are fixedly installed at both ends of the connecting shaft, respectively. The first bevel gear meshes with the second bevel gear. A support shaft is rotatably installed inside the transmission chamber. A fourth bevel gear is fixedly installed at the top of the support shaft. The fourth bevel gear meshes with the third bevel gear. A turntable is coaxially and horizontally fixed at the top of the fourth bevel gear. A lever is fixedly provided at the eccentric position of the turntable. A first drive shaft is rotatably mounted on the screen tray. A rectangular frame plate is fixedly mounted on the bottom end of the first drive shaft. The toggle block is slidably engaged inside the rectangular frame plate. The first scraper is fixedly mounted on the top end of the first drive shaft.

[0012] By using two forward reversals and speed reduction to increase torque through a four-stage bevel gear, the continuous rotation of the shaft is converted into the reciprocating oscillation of the first scraper. The transmission structure is compact and reliable, requires no electric drive, and is suitable for harsh environments with high vacuum and high temperature inside the tower.

[0013] Preferably, the collection and filtration mechanism further includes a drainage pipe and an annular spray pipe. One end of the drainage pipe is connected to the drain port of the bottommost downcomer pipe, and the other end of the drainage pipe is connected to the annular spray pipe, which is disposed inside the filter barrel.

[0014] The solid-containing liquid is evenly distributed around the circumference of the filter barrel through the annular nozzle, avoiding the concentrated impact of liquid on local areas that would lead to uneven filtration. This is beneficial for the solid impurities to adhere evenly to the inner wall of the filter barrel under the action of centrifugal force during the subsequent centrifugal filtration process, thereby improving the filtration effect.

[0015] Preferably, the centrifugal drive assembly includes an open-faced mask fixedly installed at the outlet end of the steam inlet pipe. A second drive shaft is rotatably installed inside the open-faced mask. An impeller is fixedly installed on the second drive shaft. The impeller is positioned facing the steam ejection direction of the steam inlet pipe. The bottom end of the second drive shaft extends into the interior of the filter barrel and is fixedly installed with a cone block. A baffle is fixedly installed on the outer wall of the cone block.

[0016] The distillation column itself uses its own vapor pressure to drive the high-speed rotation of the baffle plate to produce a centrifugal filtration effect, eliminating the need for an additional electrically driven centrifuge, making it energy-saving and safe.

[0017] Preferably, a crossbar is fixedly installed on the second drive shaft, and a second scraper is fixedly installed at the end of the crossbar, the second scraper being attached to the inner wall of the filter barrel.

[0018] When the second drive shaft rotates, it simultaneously drives the second scraper to scrape against the inner wall of the filter barrel in a circular motion, continuously scraping off the impurities attached to the inner wall of the filter screen, effectively preventing filter screen blockage and ensuring the stable filtration effect of the filter barrel under long-term operation.

[0019] Preferably, the bottom of the filter barrel has a funnel-shaped structure, and the drain pipe is located at the lowest point of the filter barrel.

[0020] The scraped-off solid impurities automatically converge to the lowest point along the slope of the funnel under the action of gravity, and are periodically discharged through the sewage pipe. There is no need for manual entry into the tower body for cleaning, which reduces the difficulty of maintenance and the risk of operation.

[0021] Preferably, the dial block is cylindrical in shape, and the through groove inside the rectangular frame plate is adapted to the diameter of the dial block.

[0022] The cylindrical lever slides smoothly within the through groove of the rectangular frame plate, reducing frictional resistance, avoiding impact and noise caused by excessive gaps, and ensuring transmission accuracy and smooth movement.

[0023] Preferably, the outer wall of the filter barrel is fixedly connected to the inner wall of the distillation column by a fixing rod, and multiple fixing rods are evenly arranged along the circumference of the filter barrel.

[0024] Ensure that the filter canister does not shift or shake during operation and that the force is evenly distributed, so that the liquid distribution from the annular nozzle and the centrifugal force from the deflector plate are evenly distributed around the circumference of the filter canister, thus maintaining the stability of the filtration effect.

[0025] The beneficial effects of this invention are as follows: This invention provides a precision distillation separation and purification device for mixed methylnaphthalene. By setting a V-shaped first scraper at the top of each sieve tray and cooperating with an oscillating mechanism composed of an arc-shaped cover, a rotating shaft, blades, a transmission chamber, and multi-stage bevel gears, the device utilizes the impact force of the liquid falling from the downcomer as a power source to drive the first scraper to perform stable reciprocating oscillation scraping at the top of the tray. This eliminates the need for external power during operation and allows the device to adapt to the environment inside the distillation column, avoiding the risk of vacuum failure due to dynamic seal failure, and reducing equipment energy consumption and maintenance costs. In addition, the reciprocating oscillation of the first scraper can create continuous mechanical disturbance on the tray surface, effectively breaking up large bubbles formed by rising vapor, increasing the gas-liquid contact area and extending the contact time, thereby enhancing mass and heat transfer efficiency. Thus, while ensuring the permeability of the sieve tray, it significantly improves the separation and purification effect of α-methylnaphthalene and β-methylnaphthalene with similar boiling points. By installing a funnel-shaped filter barrel at the bottom of the distillation column, the solid-containing liquid discharged from the bottom downcomer is evenly introduced into the filter barrel through a guide pipe and annular spray pipe for screening and filtration. This effectively intercepts scraped-off coke particles and other solid impurities, preventing them from entering the reboiler and causing scaling on the heat exchanger tube walls and a decrease in heat transfer efficiency. At the same time, a centrifugal drive assembly consisting of an open mask, a second drive shaft, an impeller, a cone, and a baffle is installed at the end of the steam inlet pipe. The high-pressure steam discharged from the top of the distillation column is used as a cleaning power source to drive the solid-liquid mixture in the filter barrel for high-speed centrifugal filtration, improving the filtration rate. When the second drive shaft rotates, it also drives the second scraper connected by a crossbar to rotate against the inner wall of the filter barrel, continuously scraping off the impurities attached to the inner wall of the filter screen. Combined with the funnel-shaped bottom structure, these impurities are periodically discharged through a drain pipe, effectively preventing filter screen blockage and ensuring the stability and filtration effect of the filter barrel under long-term operation, providing a reliable guarantee for the reboiling circulation of the liquid at the bottom of the column. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the internal structure of the distillation column of the present invention; Figure 2 This is a schematic cross-sectional view of the internal structure of the distillation column of the present invention; Figure 3 This is a diagram of the screen tray and bottom filtration and collection mechanism of the present invention; Figure 4 This is a schematic diagram of the internal structure of the downcomer of the present invention; Figure 5This is a schematic cross-sectional view of the screen tray and downcomer of the present invention. Figure 6 This is a schematic diagram of the overall transmission mechanism of the present invention; Figure 7 This is a schematic diagram of the top of the turntable of the present invention; Figure 8 This is a schematic diagram of the bottom structure of the V-shaped scraper of the present invention; Figure 9 This is a schematic diagram of the filtration and collection mechanism of the present invention.

[0027] In the diagram: 1. Distillation column body; 101. Spray tray; 102. Steam inlet pipe; 2. Screen tray; 3. Downcomer; 4. First scraper; 5. Swinging mechanism; 501. Arc-shaped cover plate; 502. Rotating shaft; 503. Blade plate; 504. Transmission chamber; 505. First bevel gear; 506. Second bevel gear; 507. Connecting shaft; 508. Third bevel gear; 509. Support shaft; 510. Fourth bevel gear; 511. Turntable; 512. Pulley block; 513. First drive shaft; 514. Rectangular frame plate; 6. Collection and filtration mechanism; 601. Filter barrel; 602. Drainage pipe; 603. Annular nozzle; 604. Sewage pipe; 605. Open mask; 606. Second drive shaft; 607. Impeller; 608. Cone block; 909. Baffle plate; 910. Crossbar; 911. Second scraper. Detailed Implementation

[0028] To enable those skilled in the art to more clearly understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0029] Example 1: As Figures 1-9 As shown, this embodiment provides a precision distillation separation and purification device for mixed methylnaphthalene, including a distillation column 1, a spray plate 101 located at the top of the distillation column 1, and a steam inlet pipe 102 opened on the bottom side wall of the distillation column 1. The interior of the distillation column 1 is provided with multiple layers of screen trays 2 from top to bottom, and adjacent layers of screen trays 2 are connected by downcomers 3. Each layer of screen tray 2 is equipped with a first scraper 4 at the top, and a swing mechanism 5 is installed inside the downcomer 3. The first scraper 4 is connected to the swing mechanism 5 through a transmission. The swing mechanism 5 is driven by the liquid flowing through the downcomer 3 and is used to drive the first scraper 4 to swing back and forth at the top of the screen tray 2. A collection and filtration mechanism 6 is provided at the bottom of the distillation column body 1. The collection and filtration mechanism 6 includes a filter barrel 601. The inlet of the filter barrel 601 is connected to the outlet of the bottom downcomer 3. A drain pipe 604 is provided at the bottom of the filter barrel 601. A centrifugal drive assembly is provided at the outlet of the steam inlet pipe 102. The centrifugal drive assembly is connected to the filter barrel 601 for driving the liquid in the filter barrel 601 to perform centrifugal filtration.

[0030] During operation, the mixed methylnaphthalene feedstock enters the interior of the distillation column 1 and flows down layer by layer along the screen tray 2. At the same time, steam enters the interior of the distillation column 1 through the steam inlet pipe 102 and passes through each layer of screen tray 2 from bottom to top to carry out gas-liquid contact and mass transfer with the flowing liquid. The light components are enriched at the top of the column, and the heavy components are enriched at the bottom of the column.

[0031] During the distillation process, as the liquid flows from the upper screen tray 2 to the lower screen tray 2 via the downcomer 3, the height difference of the falling liquid drives the oscillating mechanism 5 inside the downcomer 3 to operate. The oscillating mechanism 5 converts the linear motion of the falling liquid into the reciprocating oscillating motion of the first scraper 4, so that the first scraper 4 continuously scrapes and cleans the top surface of the screen tray 2, preventing coke deposits from adhering and accumulating on the surface of the screen tray 2 and the edges of the sieve holes, and ensuring the permeability of the vapor. At the same time, the reciprocating oscillation of the first scraper 4 continuously disturbs the liquid layer on the surface of the tray, breaking up large bubbles, increasing the gas-liquid contact area, and enhancing the mass and heat transfer effect.

[0032] Liquid containing coke particles is discharged into the filter tank 601 of the collection and filtration mechanism 6 through the bottom downcomer 3. It is centrifugally filtered under the drive of the centrifugal drive component. The filtered clear liquid is discharged from the filter tank 601 and enters the reboiler for recycling. The intercepted impurities are periodically discharged through the drain pipe 604, realizing solid-liquid separation and impurity collection.

[0033] Example 2: The solution in Example 1 will be further described below with reference to its specific working method. See the description below for details: In this embodiment, the first scraper 4 has a V-shaped structure, and the bottom of the first scraper 4 is in contact with the top surface of the screen tray 2.

[0034] When the first scraper 4, which has a V-shaped structure, swings back and forth with the first drive shaft 513, the inclined sides of its V-shape can push and disturb the liquid layer in different directions. The bottom of the first scraper 4 is attached to the top surface of the screen tray 2, ensuring that the dense coke layer attached to the surface of the screen tray 2 can be effectively removed during scraping.

[0035] In this embodiment, the swing mechanism 5 includes an arc-shaped cover plate 501 fixedly installed on the inner wall of the downcomer 3. A rotating shaft 502 is rotatably installed inside the arc-shaped cover plate 501. A blade 503 is fixedly installed on the rotating shaft 502. The blade 503 is positioned directly opposite the liquid falling direction of the downcomer 3. A transmission component is provided at the middle position of the arc-shaped cover plate 501. The input end of the transmission component is connected to the rotating shaft 502, and the output end of the transmission component is connected to the first scraper 4.

[0036] As the liquid flows downward from the upper screen tray 2 through the downcomer 3, it accelerates and falls under the influence of gravity, impacting the blade 503 positioned directly in the direction of descent. The impact of the liquid on the blade 503 causes the rotating shaft 502 to rotate inside the arc-shaped cover plate 501. The rotating shaft 502 transmits the rotational torque to the input end of the transmission assembly, which then outputs it from its output end, driving the first scraper 4 to reciprocate.

[0037] In this embodiment, the transmission assembly includes a transmission chamber 504 fixedly installed on the outer wall of the downcomer 3. One end of the rotating shaft 502 extends into the transmission chamber 504 and is fixedly installed with a first bevel gear 505. A connecting shaft 507 is rotatably installed inside the transmission chamber 504. A second bevel gear 506 and a third bevel gear 508 are fixedly installed at both ends of the connecting shaft 507, respectively. The first bevel gear 505 meshes with the second bevel gear 506. A support shaft 509 is rotatably installed inside the transmission chamber 504. A fourth bevel gear 510 is fixedly installed at the top of the support shaft 509. The fourth bevel gear 510 meshes with the third bevel gear 508. A turntable 511 is coaxially and horizontally fixed at the top of the fourth bevel gear 510. A toggle block 512 is fixedly provided at the eccentric position of the turntable 511. A first drive shaft 513 is rotatably mounted on the screen tray 2. A rectangular frame plate 514 is fixedly mounted on the bottom end of the first drive shaft 513. A toggle block 512 is slidably engaged inside the rectangular frame plate 514. A first scraper 4 is fixedly mounted on the top end of the first drive shaft 513.

[0038] When the rotating shaft 502 rotates, it drives the first bevel gear 505 to rotate synchronously. The first bevel gear 505 transmits power to the second bevel gear 506 that meshes with it. The second bevel gear 506 drives the third bevel gear 508 to rotate synchronously through the connecting shaft 507. The third bevel gear 508 transmits power to the fourth bevel gear 510 that meshes with it. After two positive reversals and deceleration and torque increase of the four-stage bevel gears, the power is transmitted to the turntable 511 at the top of the fourth bevel gear 510, driving the turntable 511 to rotate continuously around the axis of the support shaft 509.

[0039] When the turntable 511 rotates, the eccentrically positioned lever 512 moves in a circular motion with the turntable 511. Since the lever 512 is slidably engaged in the through groove inside the rectangular frame plate 514, the circular motion of the lever 512 is constrained by the linear through groove of the rectangular frame plate 514, transforming it into the reciprocating oscillation of the rectangular frame plate 514 around the axis of the first drive shaft 513. The rectangular frame plate 514 drives the first drive shaft 513 to reciprocate and rotate on the screen tray 2, and the first scraper 4 at the top of the first drive shaft 513 subsequently performs reciprocating scraping and cleaning and liquid layer disturbance on the surface of the screen tray 2.

[0040] In this embodiment, the collection and filtration mechanism 6 further includes a drainage pipe 602 and an annular nozzle 603. One end of the drainage pipe 602 is connected to the drain port of the bottom downcomer 3, and the other end of the drainage pipe 602 is connected to the annular nozzle 603. The annular nozzle 603 is disposed inside the filter barrel 601.

[0041] After the liquid containing coke particles is discharged from the drain outlet of the bottom downcomer 3, it is transported through the guide pipe 602 to the annular spray pipe 603 inside the filter barrel 601. The annular spray pipe 603 sprays the solid-liquid mixture evenly into the interior of the filter barrel 601 along the circumference, so that the solid-liquid mixture forms a uniform annular liquid distribution in the filter barrel 601. This avoids the liquid from concentrating and impacting local areas, which would cause uneven filtration. At the same time, it is beneficial for solid impurities to be evenly attached to the inner wall of the filter barrel 601 under the action of centrifugal force during the subsequent centrifugal filtration process.

[0042] In this embodiment, the centrifugal drive assembly includes an open mask 605 fixedly installed at the outlet end of the steam inlet pipe 102. A second drive shaft 606 is rotatably installed inside the open mask 605. An impeller 607 is fixedly installed on the second drive shaft 606. The impeller 607 is positioned facing the steam ejection direction of the steam inlet pipe 102. The bottom end of the second drive shaft 606 extends into the filter barrel 601 and a cone block 608 is fixedly installed thereon. A baffle plate 909 is fixedly installed on the outer wall of the cone block 608.

[0043] During distillation, high-pressure steam is ejected from the outlet end of the steam inlet pipe 102 and sprayed directly onto the impeller 607. The open-face mask 605 collects the steam flow in the area where the impeller 607 is located, improving the impact efficiency of the steam on the impeller 607. After being impacted by the steam, the impeller 607 drives the second drive shaft 606 to rotate continuously inside the open-face mask 605. The second drive shaft 606 transmits the rotational power to the cone block 608 inside the filter barrel 601. The cone block 608 drives the baffle plate 909 on its outer wall to rotate synchronously. The baffle plate 909 rotates at high speed inside the filter barrel 601, stirring the solid-liquid mixture inside the filter barrel 601 to produce a centrifugal effect, accelerating the liquid to pass through the filter screen and discharge, while throwing solid impurities toward the inner wall of the filter barrel 601, realizing high-speed centrifugal separation of solid and liquid.

[0044] In this embodiment, a crossbar 910 is fixedly installed on the second drive shaft 606, and a second scraper 911 is fixedly installed at the end of the crossbar 910. The second scraper 911 is attached to the inner wall of the filter barrel 601.

[0045] When the second drive shaft 606 rotates, it synchronously drives the crossbar 910 to rotate around the axis of the second drive shaft 606. The second scraper 911 at the end of the crossbar 910 then scrapes the inner wall of the filter barrel 601 in a circular motion. During the centrifugal separation process, the coke particles and other solid impurities adhering to the inner wall of the filter barrel 601 are detached from the inner wall of the filter barrel 601 under the continuous scraping of the second scraper 911. They slide down the inner wall of the bottom of the funnel-shaped filter barrel 601, collect at the lowest point of the filter barrel 601, and are periodically discharged through the drain pipe 604, effectively preventing the filter screen from clogging and maintaining the long-term filtration capacity of the filter barrel 601.

[0046] In this embodiment, the bottom of the filter bucket 601 has a funnel-shaped structure, and the drain pipe 604 is located at the lowest point of the filter bucket 601.

[0047] The bottom of the funnel-shaped filter barrel 601 allows solid impurities scraped off by the second scraper 911 to automatically converge to the lowest point along the slope of the funnel under the action of gravity. The drain pipe 604 is set at this lowest point. When the drain pipe 604 valve is opened, the accumulated impurities can be smoothly discharged with a small amount of liquid without the need for manual entry into the tower body for cleaning, thus reducing maintenance difficulty and operational risks.

[0048] In this embodiment, the toggle block 512 is cylindrical in shape, and the through groove inside the rectangular frame plate 514 is adapted to the diameter of the toggle block 512.

[0049] This allows the paddle block 512 to slide smoothly within the through groove of the rectangular frame plate 514 as it moves in a circular motion with the turntable 511, reducing frictional resistance and avoiding impact and noise caused by excessive gaps. This ensures transmission accuracy and smooth movement, and keeps the reciprocating oscillation frequency and amplitude of the first scraper 4 stable.

[0050] In this embodiment, the outer wall of the filter barrel 601 is fixedly connected to the inner wall of the distillation column 1 by a fixing rod, and multiple fixing rods are evenly arranged along the circumference of the filter barrel 601.

[0051] Multiple fixing rods securely suspend the filter barrel 601 in the bottom internal space of the distillation column 1, ensuring that the filter barrel 601 does not shift or shake during operation.

[0052] The solutions in Embodiment 1 and Embodiment 2 will be further described below with reference to their specific working methods. During operation, the mixed methylnaphthalene feedstock is conveyed into the tower body and flows downwards layer by layer along the screen trays 2. At the same time, high-pressure steam enters the tower body through the steam inlet pipe 102 on the bottom side wall of the distillation tower body 1, and passes through the sieve holes of each screen tray 2 from bottom to top. It has sufficient gas-liquid contact and mass transfer exchange with the downward flowing liquid on the surface of each screen tray 2. The light components gradually accumulate to the top of the tower, and the heavy components gradually accumulate to the bottom of the tower, so as to achieve precise separation of α-methylnaphthalene and β-methylnaphthalene in the mixed methylnaphthalene.

[0053] During the distillation process, as the liquid flows from the upper screen tray 2 through the downcomer 3 to the lower screen tray 2, the height difference of the falling liquid impacts the blades 503, driving the oscillating mechanism 5 to operate. When the rotating shaft 502 rotates, it drives the first bevel gear 505 to rotate synchronously. The first bevel gear 505 transmits power to the meshing second bevel gear 506. The second bevel gear 506 drives the third bevel gear 508 to rotate synchronously through the connecting shaft 507. The third bevel gear 508 transmits power to the meshing third bevel gear 508. The fourth bevel gear 510, after two positive reversals and deceleration and torque increase of the four-stage bevel gear, transmits power to the turntable 511 at the top of the fourth bevel gear 510, driving the turntable 511 to rotate continuously around the axis of the support shaft 509. The eccentric block 512 pushes the rectangular frame plate 514 to swing back and forth, which in turn drives the V-shaped first scraper 4 to scrape and clean the coke on the top of the screen tray 2 through the first drive shaft 513 and disturb the liquid layer, ensuring the permeability of the screen tray 2 and enhancing the gas-liquid mass transfer effect.

[0054] After the liquid containing coke particles is discharged through the bottom downcomer 3, it is evenly introduced into the filter barrel 601 through the guide pipe 602 and the annular spray pipe 603. At the same time, the high-pressure steam sprayed from the steam inlet pipe 102 impacts the impeller 607, driving the second drive shaft 606 to rotate. This causes the baffle plate 909 to rotate at high speed inside the filter barrel 601, generating a centrifugal separation effect. The clear liquid passes through the filter screen and is discharged into the reboiler for recycling, while solid impurities are intercepted on the inner wall of the filter barrel 601. The second drive shaft 606 also drives the crossbar 910 and the second scraper 911 to rotate, continuously scraping off the impurities adhering to the inner wall of the filter barrel 601. Combined with the funnel-shaped bottom structure, the impurities are periodically discharged through the drain pipe 604, achieving efficient solid-liquid separation and continuous sewage discharge.

[0055] The above description is merely a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A precision distillation separation and purification apparatus for mixed methylnaphthalene, comprising a distillation column (1), a spray plate (101) located at the top of the distillation column (1), and a steam inlet pipe (102) opened on the bottom side wall of the distillation column (1), wherein multiple layers of screen trays (2) are arranged sequentially from top to bottom inside the distillation column (1), and adjacent layers of screen trays (2) are connected by downcomers (3), characterized in that: Each layer of the screen tray (2) is provided with a first scraper (4) at the top. The downcomer (3) is provided with a swing mechanism (5). The first scraper (4) is connected to the swing mechanism (5) in a transmission. The swing mechanism (5) is driven by the liquid flowing through the downcomer (3) and is used to drive the first scraper (4) to swing back and forth at the top of the screen tray (2). The bottom end of the distillation column body (1) is provided with a collection and filtration mechanism (6), which includes a filter barrel (601). The inlet of the filter barrel (601) is connected to the outlet of the bottom downcomer (3). The bottom of the filter barrel (601) is provided with a drain pipe (604). The outlet end of the steam inlet pipe (102) is provided with a centrifugal drive assembly. The centrifugal drive assembly is connected to the filter barrel (601) for driving the liquid in the filter barrel (601) to perform centrifugal filtration.

2. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 1, characterized in that: The first scraper (4) has a V-shaped structure, and the bottom of the first scraper (4) is in contact with the top surface of the screen tray (2).

3. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 1, characterized in that: The swing mechanism (5) includes an arc-shaped cover plate (501) fixedly installed on the inner wall of the downcomer (3). A rotating shaft (502) is rotatably installed inside the arc-shaped cover plate (501). A blade (503) is fixedly installed on the rotating shaft (502). The blade (503) is positioned directly opposite the liquid falling direction of the downcomer (3). A transmission component is provided at the middle position of the arc-shaped cover plate (501). The input end of the transmission component is connected to the rotating shaft (502), and the output end of the transmission component is connected to the first scraper (4).

4. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 3, characterized in that: The transmission assembly includes a transmission chamber (504) fixedly installed on the outer wall of the downcomer (3). One end of the rotating shaft (502) extends into the transmission chamber (504) and is fixedly installed with a first bevel gear (505). A connecting shaft (507) is rotatably installed inside the transmission chamber (504). A second bevel gear (506) and a third bevel gear (508) are fixedly installed at both ends of the connecting shaft (507). The first bevel gear (505) meshes with the second bevel gear (506). A support shaft (509) is rotatably installed inside the transmission chamber (504). A fourth bevel gear (510) is fixedly installed at the top of the support shaft (509). The fourth bevel gear (510) meshes with the third bevel gear (508). A turntable (511) is coaxially and horizontally fixed at the top of the fourth bevel gear (510). A lever (512) is fixedly provided at the eccentric position of the turntable (511). A first drive shaft (513) is rotatably mounted on the screen tray (2). A rectangular frame plate (514) is fixedly mounted on the bottom end of the first drive shaft (513). The paddle block (512) is slidably engaged inside the rectangular frame plate (514). The first scraper (4) is fixedly mounted on the top end of the first drive shaft (513).

5. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 1, characterized in that: The collection and filtration mechanism (6) further includes a drainage pipe (602) and an annular nozzle (603). One end of the drainage pipe (602) is connected to the drain port of the bottommost downcomer (3), and the other end of the drainage pipe (602) is connected to the annular nozzle (603). The annular nozzle (603) is located inside the filter barrel (601).

6. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 1, characterized in that: The centrifugal drive assembly includes an open mask (605) fixedly installed at the outlet end of the steam inlet pipe (102). A second drive shaft (606) is rotatably installed inside the open mask (605). An impeller (607) is fixedly installed on the second drive shaft (606). The impeller (607) is positioned facing the steam ejection direction of the steam inlet pipe (102). The bottom end of the second drive shaft (606) extends into the filter barrel (601) and a cone block (608) is fixedly installed thereon. A baffle plate (909) is fixedly installed on the outer wall of the cone block (608).

7. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 6, characterized in that: A crossbar (910) is fixedly installed on the second drive shaft (606), and a second scraper (911) is fixedly installed at the end of the crossbar (910). The second scraper (911) is attached to the inner wall of the filter barrel (601).

8. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 1, characterized in that: The bottom of the filter barrel (601) has a funnel-shaped structure, and the drain pipe (604) is located at the lowest point of the filter barrel (601).

9. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 4, characterized in that: The dial block (512) is cylindrical in shape, and the through groove inside the rectangular frame plate (514) is adapted to the diameter of the dial block (512).

10. The mixed methylnaphthalene precision distillation separation and purification apparatus according to claim 1, characterized in that: The outer wall of the filter barrel (601) is fixedly connected to the inner wall of the distillation column (1) by a fixing rod, and multiple fixing rods are evenly arranged along the circumference of the filter barrel (601).

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