Moisture content dynamic monitoring device for benzethonium chloride decompression crystallization
By incorporating a scraper and rinsing system into the infrared probe device, the problem of crystal film coverage in the detection window was solved, enabling accurate and continuous monitoring of moisture content during the crystallization process of benzyl chloride, thus ensuring the stability and precision of the detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-14
- Publication Date
- 2026-04-07
AI Technical Summary
During the vacuum crystallization process of benzyl chloride, the detection window of the infrared probe is easily covered by the crystal film, resulting in inaccurate moisture content monitoring and signal interruption, which is difficult to solve effectively with existing technologies.
Design a device that includes a scraper and an infrared detection probe. The scraper is driven by a geared motor to rotate around a rotating shaft to remove the crystal film layer on the detection window, and the probe is rinsed in real time through the liquid inlet and liquid outlet to ensure the cleanliness of the detection end.
It achieves accurate and continuous moisture content monitoring, prevents crystal adhesion, improves detection precision and stability, and extends the service life of the device.
Smart Images
Figure CN121805151A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of moisture detection technology, specifically to a dynamic monitoring device for the moisture content of benzyl chloride crystallization under reduced pressure. Background Technology
[0002] Near-infrared spectroscopy has the advantages of rapid response, no sampling required, and simultaneous detection of multiple components. It has been applied to the moisture monitoring of the benzyl chloride crystallization process. When detecting moisture, the fiber optic probe is directly inserted into the crystallization slurry through the flange on the side wall of the reactor. A quantitative model is established by utilizing the characteristic absorption of water molecules in the near-infrared region, thereby realizing the dynamic monitoring of moisture content.
[0003] However, in actual production processes, during the reduced-pressure crystallization of benzyl chloride using near-infrared spectroscopy, benzyl chloride crystals readily undergo heterogeneous nucleation and adhesion growth on the sapphire detection window surface of the near-infrared probe. This is especially true during the stage where reduced-pressure evaporation leads to solvent removal and increased supersaturation. The probe window area often becomes a preferential precipitation site for crystals due to localized flow stagnation or a slightly lower temperature than the bulk material. As the crystallization process progresses, the adhered crystals gradually accumulate, forming an opaque or semi-transparent dense crystalline film. This crystalline film exhibits strong scattering and absorption effects on near-infrared light, preventing the incident light from being absorbed. While the probe can effectively penetrate the window to reach deeper materials, the reflected or transmitted spectral signals received by the probe are also severely interfered with by the crystal film layer. This causes a continuous attenuation of the infrared spectral signal intensity and irreversible baseline drift. The quantitative model established based on the clean window becomes completely ineffective, ultimately leading to a significant deviation of the moisture content monitoring value from the true value, or even signal interruption and inability to obtain effective readings. This forces operators to frequently interrupt the crystallization process to disassemble the probe for manual cleaning, which not only disrupts the stability of the crystallization process but also makes it difficult for online monitoring technology to play its due process control value in actual production. Summary of the Invention
[0004] The purpose of this invention is to provide a dynamic monitoring device for the moisture content of benzyl chloride crystallization under reduced pressure, in order to solve the problem that when using an infrared probe for moisture detection, benzyl chloride crystals easily form an opaque or semi-transparent crystal film on the probe's detection window. The crystal film layer attached to the window scatters and absorbs incident light, resulting in insufficient light intensity reaching the deeper material and thus inaccurate moisture content detection results.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A dynamic monitoring device for the moisture content of benzyl chloride during vacuum crystallization includes a mounting flange, a mounting block, and an infrared detection probe for moisture content monitoring. The mounting block is coaxially fixedly connected to the mounting flange, and the mounting block completely seals the inner hole of the mounting flange. A mounting hole is provided inside the mounting block, and the infrared detection probe is fixedly installed in the mounting hole, with the detection end of the infrared detection probe flush with the front face of the mounting block. An insertion hole is coaxially provided on the mounting block, and a rotating shaft is rotatably connected to the insertion hole. Both ends of the rotating shaft extend to the outer sides of the mounting block, respectively. A scraper is fixedly installed at the end of the rotating shaft extending to the front side of the mounting block, and the scraper is in contact with the mounting block on the side facing the mounting block. A geared motor is fixedly connected to the mounting flange, and the output shaft of the geared motor is powered by a gear connecting to the side of the rotating shaft extending to the rear side of the mounting block. When the infrared detection probe detects moisture content, the geared motor drives the scraper to rotate, and the front and rear projections of the detection end of the infrared detection probe are located within the rotation area of the scraper.
[0006] By setting a scraper at the front end of the mounting block, when the infrared detection probe detects moisture content, the geared motor synchronously drives the scraper to make a circular motion around the rotating shaft. Since the front and rear projections of the detection end of the infrared detection probe are always within the coverage area of the scraper's rotation trajectory, the outer edge of the rear side of the scraper continuously sweeps the surface of the detection window during the rotation process. When benzyl chloride crystals form heterogeneous nuclei on the surface of the detection window, the edge of the scraper mechanically removes the newly formed crystal nuclei in real time, avoiding the formation of a crystal film. This solves the problem of monitoring failure caused by crystal adhesion during the crystallization of benzyl chloride by the infrared detection probe, ensuring the accuracy and continuity of moisture content monitoring.
[0007] Preferably, the rotating shaft has a liquid inlet hole coaxially formed on it, the liquid inlet hole does not penetrate the front end of the rotating shaft, the scraper has a drain hole coaxially formed inside it, the drain hole is connected to the liquid inlet hole, and the drain hole does not penetrate the end of the scraper away from the rotating shaft, the scraper has a groove facing the mounting block, and the groove is formed in the positive direction of the scraper's rotation, the groove penetrates 1 / 4 of the drain hole to form a drain outlet, and the drain outlet faces the front end of the mounting block.
[0008] By setting an inlet hole on the rotating shaft and a groove, drain hole, and outlet on the scraper, solvent or purified water is injected into the rotating shaft through the inlet hole when the device is running. The liquid flows to the groove through the drain hole and is sprayed out of the groove from the outlet. When the scraper rotates to the infrared detection probe, the high-pressure water discharged from the outlet sprays onto the detection end of the infrared detection probe, thereby rinsing the detection end and thoroughly removing tiny crystal particles or residues adhering to it. This effectively prevents secondary adhesion and accumulation of crystals on the detection end surface, ensuring that the detection end remains clean at all times, thus improving the accuracy and stability of moisture content detection. Furthermore, the discharged liquid forms a liquid film between the scraper and the front face of the mounting block, which acts as a lubricant, reducing frictional resistance during scraper rotation, reducing wear, and extending the service life of the device. At the same time, it ensures that the scraper can continuously and stably perform its scraping function, guaranteeing the accuracy and reliability of moisture content monitoring.
[0009] Preferably, the scraper includes a rigid part and a scraping blade part, the drain hole is opened on the rigid part, the scraping blade part is fixedly connected to the rear end of the rigid part, and the rear end of the scraping blade part is in contact with the front end face of the mounting block.
[0010] The scraper is designed as a combination of a rigid section and a scraping blade. The rigid section provides a stable support frame for the scraper, ensuring that it will not deform or break during high-speed rotation, thus guaranteeing the unobstructed drainage holes and the normal functioning of the drainage. The scraping blade is made of a highly wear-resistant material and fits snugly against the front end of the mounting block. It can scrape away newly formed crystal nuclei and tiny crystal particles on the surface of the detection window. At the same time, the scraping blade is made of a material softer than the infrared detection probe, thereby reducing damage to the surface of the detection window caused by the scraping blade and avoiding scratches that could affect the detection accuracy of the infrared detection probe, further ensuring the accuracy of moisture content monitoring.
[0011] Preferably, the rear end of the rotating shaft extends to the rear side of the mounting flange, and a pressure spring is coaxially connected to one side of the rotating shaft extending to the rear side of the mounting flange. Both ends of the pressure spring are coaxially fixedly connected to connecting rings. A fixing ring is coaxially provided at the rear end of the rotating shaft, and the connecting rings at the front and rear ends are rotatably connected to the mounting flange and the fixing ring, respectively.
[0012] By installing a pressure spring and a connecting ring at the rear end of the rotating shaft, when the rotating shaft undergoes axial displacement due to temperature changes or mechanical vibration during operation, the pressure spring can absorb and buffer the axial force through its own elastic deformation, keeping the rotating shaft in a stable axial position and preventing the axial movement of the rotating shaft from affecting the rotation accuracy and scraping function of the scraper. Furthermore, the connecting ring adopts a rotating connection method, which not only ensures a reliable connection between the pressure spring and the mounting flange and the fixed ring, but also reduces the frictional resistance during rotation, ensuring that the rotating shaft can rotate smoothly, thereby ensuring the stable operation of the entire device and the accuracy of moisture content monitoring.
[0013] Preferably, the connecting ring includes a metal ring and a graphite ring, and the metal rings on both sides of the connecting ring are fixedly connected to the pressure spring.
[0014] The connecting ring is designed as a combination of a metal ring and a graphite ring. The metal ring provides sufficient structural strength and rigidity to ensure that the connecting ring will not deform or be damaged when subjected to the force of the pressure spring, thus guaranteeing a stable connection between the pressure spring and the mounting flange and the fixed ring. The graphite ring has self-lubricating properties, which can effectively reduce friction between the connecting ring and the mounting flange and the fixed ring, reduce energy loss during rotation, make the shaft rotate more smoothly, and reduce the heat generated by friction, avoiding the impact of temperature rise on the performance of the device, and further improving the stability and reliability of the device operation.
[0015] Preferably, the front end of the mounting flange is coaxially connected to a fixed flange, and the axis of the fixed flange is inclined at an angle to the horizontal plane. The inclined angle is located above the horizontal plane, and the value range of the inclined angle is 10° to 20°.
[0016] By setting a 10°–20° angle between the axis of the fixed flange and the horizontal plane, the entire monitoring device is installed at a certain angle. This design allows the crystal particles and liquid scraped off by the scraper to flow naturally downwards under gravity during rotation, preventing accumulation on the front face of the mounting block and the scraper surface, thus preventing secondary adhesion and crystallization. At the same time, the inclined design also facilitates the formation of a uniform liquid film on the front face of the mounting block, further enhancing the lubrication effect, reducing friction between the scraper and the mounting block, reducing wear, extending the service life of the device, and ensuring the continuous stability and accuracy of moisture content monitoring.
[0017] Preferably, the rigid part is provided with an elastic plate, the elastic plate is the same length as the groove, one end of the elastic plate is fixedly connected to the rigid part, and the other end is in a free state. When there is no liquid pressure in the drain hole, the elastic plate completely closes the drain hole.
[0018] When no liquid is injected into the drain hole or the liquid pressure is insufficient, the elastic plate completely covers and seals the drain hole with its own elastic force, effectively preventing external crystal particles or impurities from entering the drain hole and causing blockage. At the same time, it prevents liquid from the front face of the mounting block from flowing back into the drain hole through the drain hole when not flushing, ensuring that the inside of the drain hole is clean and unobstructed. When liquid enters the drain hole through the inlet hole and reaches a certain pressure, the liquid pressure overcomes the elastic resistance of the elastic plate, lifting the free end of the elastic plate and opening the drain hole. The liquid is then sprayed out from the drain hole at high speed, achieving flushing of the detection end of the infrared detection probe. Through the automatic opening and closing function of the elastic plate, the dynamic sealing and opening of the drain hole are realized, ensuring both effective liquid spraying during flushing and the sealing of the drain hole when not flushing, thus improving the reliability and stability of the device.
[0019] Preferably, the rigid part is provided with a reinforcing rib, which is located on the side away from the groove and is triangular in shape.
[0020] Triangular reinforcing ribs are set on the rigid part and arranged on the side away from the groove opening. The triangular reinforcing ribs enhance the structural strength and rigidity of the rigid part. During the high-speed rotation of the scraper, they can effectively resist the stress generated by centrifugal force, liquid impact force, etc., prevent the rigid part from deforming or breaking, ensure the stability of the overall scraper structure, and ensure the smooth flow of the drain hole and the normal realization of the drain function.
[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention solves the problem of monitoring failure caused by crystal adhesion in the crystallization process of benzyl chloride ammonium by setting a scraper at the front end of the mounting block, and the front and rear projection of the infrared detection probe is always within the coverage of the rotation trajectory of the scraper. When the scraper rotates, its rear outer edge continuously sweeps the surface of the detection window to avoid the formation of crystal film. This ensures the accuracy and continuity of moisture content monitoring.
[0022] 2. This invention provides a liquid inlet hole on the rotating shaft and a groove, drain hole, and drain outlet on the scraper. This allows the device to inject solvent or pure water through the liquid inlet hole during operation. The liquid flows through the drain hole to the groove and is sprayed out from the drain outlet, providing real-time rinsing of the infrared detection probe's detection end. This thoroughly removes tiny crystal particles or residues, effectively preventing secondary crystal adhesion. The discharged liquid forms a lubricating film between the scraper and the front end face of the mounting block, thereby improving the accuracy and stability of moisture content detection.
[0023] 3. By setting an elastic plate inside the rigid part, the present invention achieves dynamic sealing and opening of the drain port through the automatic opening and closing function of the elastic plate, effectively preventing blockage by crystal particles or impurities and backflow of liquid, further improving the reliability and stability of the device, and ensuring the continuous accuracy and reliability of moisture content monitoring. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the dynamic monitoring device for moisture content of benzyl chloride for vacuum crystallization according to the present invention; Figure 2 This is a left view of the device for dynamically monitoring the moisture content of benzyl chloride during vacuum crystallization according to the present invention. Figure 3 for Figure 2 View B in the middle; Figure 4 for Figure 3 Full sectional view of CC; Figure 5 for Figure 4 A magnified view of a section at point E in the middle; Figure 6 A diagram showing the deformation of the elastic sheet caused by the liquid pressure generated inside the drain hole; Figure 7 for Figure 3 Full sectional view of DD; Figure 8 for Figure 7 A magnified view of a section at point F in the middle; Figure 9 for Figure 7 A magnified view of a section at point G.
[0025] In the diagram: 1. Mounting flange; 2. Mounting block; 201. Mounting hole; 202. Insertion hole; 3. Infrared detection probe; 4. Rotating shaft; 401. Liquid inlet; 5. Scraper; 501. Rigid part; 5011. Drain hole; 5012. Groove; 5013. Drain outlet; 502. Scraper blade; 6. Gear motor; 7. Pressure spring; 8. Connecting ring; 801. Metal ring; 802. Graphite ring; 9. Fixing ring; 10. Fixing flange; 11. Elastic plate; 12. Reinforcing rib; A. Inclined angle. Detailed Implementation
[0026] Please see Figures 1 to 9 This invention provides a device for dynamically monitoring the moisture content of benzyl chloride during vacuum crystallization, the technical solution of which is as follows: Please refer to the following: A dynamic monitoring device for the moisture content of benzyl chloride during vacuum crystallization. Figures 1 to 5The system includes a mounting flange 1, a mounting block 2, and an infrared detector 3 for moisture content monitoring. A fixed flange 10 is coaxially connected to the front end of the mounting flange 1. The axis of the fixed flange 10 has an inclined angle A with the horizontal plane, which is above the horizontal plane and has a range of 15°. The mounting block 2 is coaxially fixedly connected inside the mounting flange 1, completely sealing the inner hole of the mounting flange 1. A mounting hole 201 is provided inside the mounting block 2. The infrared detector 3 is fixedly installed inside the mounting hole 201, with the detection end of the infrared detector 3 flush with the front end face of the mounting block 2. An insertion hole 202 is coaxially provided on the mounting block 2. A rotating shaft 4 is rotatably connected inside the insertion hole 202. Both ends of the rotating shaft 4 extend to the sides of the mounting block 2, and the rotating shaft 4 extends to the front side of the mounting block 2. A scraper 5 is fixedly installed at one end, and the scraper 5 is attached to the mounting block 2 on the side facing the mounting block 2. A geared motor 6 is fixedly connected to the mounting flange 1. The output shaft of the geared motor 6 and the rotating shaft 4 extend to the rear side of the mounting block 2 and are connected by gears. When the infrared detection probe 3 detects the moisture content, the geared motor 6 drives the scraper 5 to rotate. The front and rear projections of the detection end of the infrared detection probe 3 are located in the rotation area of the scraper 5. The scraper 5 includes a rigid part 501 and a scraping blade part 502. The drain hole 5011 is opened on the rigid part 501. The scraping blade part 502 is fixedly connected to the rear end of the rigid part 501. The rear end of the scraping blade part 502 is attached to the front end face of the mounting block 2. A reinforcing rib 12 is provided on the rigid part 501. The reinforcing rib 12 is located on the side away from the groove 5012. The reinforcing rib 12 is triangular.
[0027] For further details, please refer to Figure 5 , Figures 7 to 9A liquid inlet hole 401 is coaxially formed on the rotating shaft 4. The liquid inlet hole 401 does not penetrate the front end of the rotating shaft 4. A liquid outlet hole 5011 is coaxially formed inside the scraper 5. The liquid outlet hole 5011 is connected to the liquid inlet hole 401, and the liquid outlet hole 5011 does not penetrate the end of the scraper 5 away from the rotating shaft 4. A groove 5012 is formed on the scraper 5 facing the mounting block 2, and the groove 5012 is formed in the positive direction of rotation of the scraper 5. The groove 5012 penetrates 1 / 4 of the liquid outlet hole 5011 to form a liquid outlet 5013. The liquid outlet 5013 faces the front end of the mounting block 2. An elastic plate 11 is provided on the rigid part 501. The elastic plate 11 has the same length as the groove 5012. One end of the 1 is fixedly connected to the rigid part 501, and the other end is in a free state. When there is no liquid pressure in the drain hole 5011, the elastic plate 11 completely closes the drain port 5013. The rear end of the rotating shaft 4 extends to the rear side of the mounting flange 1. A pressure spring 7 is coaxially connected to one side of the rotating shaft 4 that extends to the rear side of the mounting flange 1. Both the front and rear ends of the pressure spring 7 are coaxially fixedly connected to the connecting ring 8. The rear end of the rotating shaft 4 is coaxially provided with a fixing ring 9. The connecting rings 8 at the front and rear ends are rotatably connected to the mounting flange 1 and the fixing ring 9, respectively. The connecting ring 8 includes a metal ring 801 and a graphite ring 802. The metal rings 801 on both sides of the connecting ring 8 are fixedly connected to the pressure spring 7.
[0028] Working principle: Please refer to Figures 1 to 9During device operation, the geared motor 6 starts, driving the rotating shaft 4 to rotate via gear transmission. This, in turn, drives the scraper 5 to perform a circular motion on the front end face of the mounting block 2. Since the front and rear projections of the infrared detection probe 3 are always within the rotation trajectory coverage of the scraper 5, the outer rear edge of the scraper 5 continuously sweeps across the detection window surface as it rotates, promptly removing newly formed crystal nuclei and preventing the formation of a crystal film. This ensures that the infrared detection probe 3 can continuously and accurately monitor the moisture content. Simultaneously, solvent or pure water is injected into the rotating shaft 4 through the liquid inlet 401. The liquid flows through the drain hole 5011 to the slot 5012, and under the action of liquid pressure, it overcomes the elastic resistance of the elastic plate 11, lifting the free end of the elastic plate 11 and opening the drain port 5013. The liquid is then sprayed out at high speed from the drain port 5013, spraying onto the detection end of the infrared detection probe 3 for real-time rinsing. This thoroughly removes tiny crystal particles or residues adhering to the detection end, effectively preventing secondary crystal adhesion. The discharged liquid forms a uniform liquid film between the scraper 5 and the front end face of the mounting block 2, which serves as a lubricant, reduces frictional resistance during scraper 5 rotation, reduces wear, and extends the service life of the device. When the rotating shaft 4 experiences axial displacement due to temperature changes or mechanical vibration during device operation, the pressure spring 7 absorbs and buffers the axial force through its own elastic deformation, keeping the rotating shaft 4 in a stable axial position and preventing axial movement of the rotating shaft 4 from affecting the rotational accuracy and scraping function of the scraper 5. The graphite ring 802 in the connecting ring 8 has self-lubricating properties, which can effectively reduce friction between the connecting ring 8 and the mounting flange 1 and the fixing ring 9, reduce energy loss during rotation, and make the rotation of the rotating shaft 4 smoother. The triangular reinforcing ribs 12 provided on the rigid part 501 enhance the structural strength and rigidity of the rigid part 501. During the high-speed rotation of the scraper 5, they can effectively resist stress generated by centrifugal force, liquid impact force, etc., prevent deformation or breakage of the rigid part 501, ensure the stability of the overall structure of the scraper 5, ensure the unobstructed flow of the drain hole 5011, and ensure the normal realization of the draining function. When there is no liquid pressure or insufficient liquid pressure in the drain hole 5011, the elastic plate 11 completely covers and seals the drain port 5013 using its own elastic force. This effectively prevents external crystal particles or impurities from entering the drain hole 5011 through the drain port 5013 and causing blockage. Simultaneously, it prevents liquid from the front face of the mounting block 2 from flowing back into the drain hole 5011 through the drain port 5013 when not being flushed, ensuring that the inside of the drain hole 5011 is clean and unobstructed. Through the coordinated operation of these components, the device achieves dynamic and accurate monitoring of the moisture content during the vacuum crystallization process of benzyl chloride.
[0029] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.
Claims
1. A device for dynamically monitoring the moisture content of benzyl chloride during vacuum crystallization, characterized in that, The device includes a mounting flange (1), a mounting block (2), and an infrared detection probe (3) for moisture content monitoring. The mounting block (2) is coaxially fixedly connected to the mounting flange (1), and the mounting block (2) completely seals the inner hole of the mounting flange (1). The mounting block (2) has a mounting hole (201) inside, and the infrared detection probe (3) is fixedly installed in the mounting hole (201). The detection end of the infrared detection probe (3) is flush with the front end face of the mounting block (2). The mounting block (2) has a coaxial insertion hole (202), and a rotating shaft (4) is rotatably connected in the insertion hole (202). The two ends of the rotating shaft (4) are... Extending to both sides of the mounting block (2), the rotating shaft (4) extends to one end of the front side of the mounting block (2) and a scraper (5) is fixedly installed thereon. The scraper (5) is attached to the mounting block (2) on the side facing the mounting block (2). A geared motor (6) is fixedly connected to the mounting flange (1). The output shaft of the geared motor (6) is connected to the side of the rotating shaft (4) extending to the rear side of the mounting block (2) by a gear. When the infrared detection probe (3) detects the moisture content, the geared motor (6) drives the scraper (5) to rotate. The front and rear projections of the detection end of the infrared detection probe (3) are located in the rotation area of the scraper (5).
2. The device for dynamic monitoring of moisture content during vacuum crystallization of benzyl chloride according to claim 1, characterized in that, A liquid inlet hole (401) is coaxially provided on the rotating shaft (4). The liquid inlet hole (401) does not penetrate the front end of the rotating shaft (4). A drain hole (5011) is coaxially provided inside the scraper (5). The drain hole (5011) is connected to the liquid inlet hole (401). The drain hole (5011) does not penetrate the end of the scraper (5) away from the rotating shaft (4). A groove (5012) is provided on the scraper (5) facing the mounting block (2). The groove (5012) is located in the positive direction of rotation of the scraper (5). The groove (5012) penetrates 1 / 4 of the drain hole (5011) to form a drain outlet (5013). The drain outlet (5013) faces the front end of the mounting block (2).
3. The device for dynamic monitoring of moisture content in benzyl chloride crystallization under reduced pressure according to claim 2, characterized in that, The scraper (5) includes a rigid part (501) and a scraping blade part (502). The drain hole (5011) is opened on the rigid part (501). The scraping blade part (502) is fixedly connected to the rear end of the rigid part (501). The rear end of the scraping blade part (502) is in contact with the front end face of the mounting block (2).
4. The device for dynamic monitoring of moisture content in benzyl chloride crystallization under reduced pressure according to claim 1, characterized in that, The rear end of the rotating shaft (4) extends to the rear side of the mounting flange (1). A pressure spring (7) is coaxially connected to one side of the rotating shaft (4) extending to the rear side of the mounting flange (1). Both ends of the pressure spring (7) are coaxially fixedly connected to connecting rings (8). A fixing ring (9) is coaxially provided at the rear end of the rotating shaft (4). The connecting rings (8) at the front and rear ends are rotatably connected to the mounting flange (1) and the fixing ring (9), respectively.
5. The device for dynamic monitoring of moisture content in benzyl chloride crystallization under reduced pressure according to claim 4, characterized in that, The connecting ring (8) includes a metal ring (801) and a graphite ring (802), and the metal rings (801) on both sides of the connecting ring (8) are fixedly connected to the pressure spring (7).
6. The device for dynamic monitoring of moisture content in benzyl chloride crystallization under reduced pressure according to claim 1, characterized in that, The front end of the mounting flange (1) is coaxially connected to a fixed flange (10). The axis of the fixed flange (10) is provided with an inclined angle (A) between it and the horizontal plane. The inclined angle (A) is located above the horizontal plane, and the value range of the inclined angle (A) is 10° to 20°.
7. The device for dynamic monitoring of moisture content in benzyl chloride crystallization under reduced pressure according to claim 3, characterized in that, The rigid part (501) is provided with an elastic plate (11). The elastic plate (11) has the same length as the groove (5012). One end of the elastic plate (11) is fixedly connected to the rigid part (501), and the other end is in a free state. When there is no liquid pressure in the drain hole (5011), the elastic plate (11) completely closes the drain hole (5013).
8. The device for dynamic monitoring of moisture content in benzyl chloride crystallization under reduced pressure according to claim 3, characterized in that, The rigid part (501) is provided with a reinforcing rib (12), which is located on the side away from the groove (5012) and is triangular in shape.