Polyvinylpyrrolidone crosslinking polymerization stirring device

Abstract

The present application relates to polyvinyl alcohol polymerization stirring technical field, specifically speaking is polyvinyl alcohol crosslinking polymerization stirring device, including box, the outer wall of box is equipped with cooling water jacket, the upper end of the inside of box is movably connected with upper stirring shaft, the outer wall of upper stirring shaft is provided with multiple upper stirring rods with circle center array, the lower end of upper stirring shaft is equipped with upper annular ratchet part, the lower end of the inside of box is movably connected with lower stirring shaft, the outer wall of lower stirring shaft is provided with multiple lower stirring rods with circle center array, and upper stirring rod and lower stirring rod are one-to-one corresponding contact settings;The present application breaks through the heat exchange bottleneck brought by low thermal conductivity of powder by extending the built-in paraffin fan-shaped bag in powder stage and directly extending the heat exchange surface into the inside of powder accumulation layer;Using the constant temperature latent heat characteristics of paraffin phase change, the core temperature of powder can be clamped below the deterioration threshold, effectively avoiding quality problems such as crosslinking abnormality, swelling performance decline and carbonization black spot, and improving product batch uniformity.

Description

Technical Field

[0001] This invention relates to the field of polyvinyl chloride polymerization stirring technology, specifically to a polyvinyl chloride crosslinking polymerization stirring device. Background Technology

[0002] Cross-linked povidone, also known as cross-linked polyvinylpyrrolidone (PVPP), is a water-insoluble homopolymer obtained by cross-linking polymerization of N-vinyl-2-pyrrolidone. As a pharmaceutical excipient listed in pharmacopoeias of various countries, it is one of the most widely used superdisintegrants in the field of solid dosage forms. Through the capillary action formed by the three-dimensional cross-linked network and its rapid water absorption and swelling properties, cross-linked povidone can significantly accelerate the disintegration rate of tablets, granules, and capsules, promoting the dissolution and release of active pharmaceutical ingredients. Its cross-linking uniformity, swelling performance, and purity level directly determine the clinical efficacy stability and medication safety of the formulation.

[0003] Currently, the industrial production of cross-linked polyvinylpyrrolidone mostly employs solution cross-linking polymerization. Under a nitrogen-inert protective atmosphere, sodium hydroxide solution is used as an initiator to induce free radical cross-linking polymerization of N-vinylpyrrolidone (NVP) monomers. This reaction process is accompanied by obvious phase transformation characteristics: in the early stage of the reaction, the system is a homogeneous liquid, and the monomer and initiator can be uniformly mixed through fluid convection; as the polymerization reaction continues, the molecular chains continuously extend and gradually form a three-dimensional cross-linked network, and the viscosity of the system continuously increases, transitioning from a liquid state to a viscous paste state; in the middle and late stages of the reaction, the system completes the liquid-solid phase transformation, forming a powdery cross-linked homopolymer crude product, which is then further processed through centrifugal dehydration, spray drying, sieving and grading to obtain the finished cross-linked polyvinylpyrrolidone.

[0004] Crosslinking polymerization is an exothermic reaction. In the production process, the conventional temperature control scheme of "external cooling water jacket + mechanical stirring" is usually adopted: the stirring mechanism continuously agitates the material in the reactor, so that the material particles are in full contact with the inner wall of the reactor. The circulating cooling water in the cooling water jacket on the outside of the reactor removes the exothermic reaction through heat conduction, and maintains the system temperature within the process setting range.

[0005] However, the aforementioned temperature control scheme has significant technical limitations after the reaction enters the powder stage. The thermal conductivity of cross-linked polyvinyl acetate powder in its packed state is only 0.1~0.2 W / (m・K), making it a poor conductor of heat. The resistance to heat conduction within the powder pack is extremely high. After the reaction enters the powder stage, the unreacted residual monomers continue to release the heat of polymerization. This heat is difficult to conduct through the low thermal conductivity powder layer to the heat exchange surface of the reactor wall, and thus accumulates rapidly within the powder pack, forming local hot spots with temperatures far exceeding the set value of the reactor wall.

[0006] In the industry, the critical temperature range in which the quality indicators of cross-linked povidone exceed pharmaceutical standards after heating is generally defined as the product degradation threshold. This threshold is not a single fixed temperature point, but a dynamically changing graded range that varies with the duration of heating. It is mainly divided into three levels: The first level is the initial threshold for performance degradation, usually 55~60℃ (continuous heating for more than 2 hours). Within this temperature range, the cross-linking reaction that has not been completely terminated will proceed excessively, causing the product cross-linking to deviate from the qualified range and the water absorption and swelling rate to decrease, directly weakening its core function as a disintegrant. Moreover, there are no visible changes in appearance at this stage, which is a hidden quality defect and is also the most likely quality control blind spot to occur in production management. The first level is the appearance and purity degradation threshold, usually 80~100℃ (continuous heating for more than 1 hour). At this temperature, the polymer undergoes thermal oxidative degradation, generating colored low-molecular-weight byproducts, and the product's appearance turns yellow. At the same time, purity indicators such as soluble matter and peroxides are likely to exceed pharmacopoeia limits. The third level is the severe degradation threshold, usually above 130℃. When local hot spots reach this temperature, it will cause deep carbonization of the polymer, forming visible carbon black spots, causing the entire batch of products to be scrapped directly. When the temperature is further raised to 160~170℃, it will also cause the polymer main chain to break down and decompose, releasing nitrogen-containing volatile byproducts, which will bring production safety hazards. Summary of the Invention

[0007] To address the problems in the prior art, the present invention provides a stirring device for crosslinking polymerization of polyvinyl chloride.

[0008] The technical solution adopted by the present invention to solve its technical problem is: a polyvinyl ketone crosslinking polymerization stirring device, including a box body, a cooling water jacket provided on the outer wall of the box body, an upper stirring shaft movably connected to the upper end of the box body, a plurality of upper stirring rods arranged in a circular array on the outer wall of the upper stirring shaft, an upper annular ratchet part provided at the lower end of the upper stirring shaft, a lower stirring shaft movably connected to the lower end of the box body, a plurality of lower stirring rods arranged in a circular array on the outer wall of the lower stirring shaft, and the upper stirring rods and lower stirring rods are arranged in a one-to-one correspondence and contact arrangement, and a lower annular ratchet part that meshes with the upper annular ratchet part is provided at the upper end of the lower stirring shaft; A cooling assembly is provided between the upper stirring rod and the lower stirring rod. The cooling assembly includes a rotating shaft rotatably connected to the side wall of the lower stirring rod via a connecting block. A fan-shaped bag is wound on the rotating shaft. The fan-shaped bag has a cavity inside, and the cavity contains solid paraffin wax. A torsion spring is symmetrically provided on the rotating shaft, and the two ends of the torsion spring are fixedly connected to the side wall of the lower stirring rod and the rotating shaft, respectively. The upper part of the housing is equipped with a drive assembly for driving the upper and lower stirring shafts to rotate.

[0009] Specifically, the drive assembly includes a servo motor mounted on the upper end of the housing via a mounting bracket. The servo motor is connected to a drive shaft via a worm gear reducer, and the drive shaft is movably inserted into an upper stirring shaft with a hollow internal structure. Multiple strip-shaped limiting blocks are arranged in a circular array on the inner wall of the upper stirring shaft, and multiple limiting grooves are arranged in a circular array on the outer wall of the drive shaft. The strip-shaped limiting blocks are correspondingly arranged in the limiting grooves.

[0010] Specifically, the lower end of the lower stirring shaft moves through the housing, and a ratchet is fixedly connected to the end of the lower stirring shaft. A pawl is engaged with the ratchet, and a telescopic rod is fixedly connected to the other end of the pawl. The telescopic rod is fixedly connected to a fixed block at the lower end of the housing, and a spring that wraps around the telescopic rod is fixedly connected between the pawl and the fixed block.

[0011] Specifically, an elastic wear-resistant sleeve is provided between the lower end of the mounting bracket and the upper end of the upper stirring shaft, and the elastic wear-resistant sleeve is movably mounted on the drive shaft.

[0012] Specifically, a sealing sleeve is bonded to the upper end of the lower stirring shaft, and the upper end of the sealing sleeve wraps around the lower end of the upper stirring shaft.

[0013] Specifically, the lower end of the pawl is provided with a handle.

[0014] Specifically, the upper end of the box is provided with a feeding funnel, and the lower end of the box is provided with a feeding pipe.

[0015] Specifically, the upper and lower ends of the outer wall of the housing are provided with inlet and outlet pipes that connect to the cooling water jacket.

[0016] Specifically, a controller is provided on the outer wall of the housing, and the servo motor is electrically connected to the controller.

[0017] The beneficial effects of this invention are as follows: This invention can eliminate local hot spots inside the powder at the source, significantly improving temperature control accuracy and uniformity. Unlike traditional external cooling water jackets that can only exchange heat from the reactor wall, this device can directly unfold and insert a fan-shaped bag containing paraffin wax into the core area of ​​the powder accumulation layer after the reaction enters the powder stage. This significantly shortens the heat exchange path from "powder accumulation layer—reactor wall—cooling water" to "powder—bag wall—paraffin wax," completely overcoming the thermal resistance bottleneck caused by the low thermal conductivity of the powder. Utilizing the isothermal latent heat characteristics of the solid-liquid phase change process of paraffin wax, the internal temperature of the powder can be precisely clamped within a safe range below the product degradation threshold, effectively avoiding quality problems such as abnormal cross-linking degree, decreased swelling performance, product yellowing, and carbonization black spots caused by local overheating. At the same time, there is no need to passively control the temperature by reducing the reaction rate and extending the reaction cycle. It can maintain a normal reaction rate while ensuring product quality, significantly improving production efficiency. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 A schematic diagram of the structure of the polyvinyl chloride crosslinking polymerization stirring device provided by the present invention. Figure 1 ; Figure 2 A schematic diagram of the structure of the polyvinyl chloride crosslinking polymerization stirring device provided by the present invention. Figure 2 ; Figure 3 The povidone crosslinking polymerization stirring device provided by the present invention Figure 2 Enlarged structural diagram at point A in the middle; Figure 4 Schematic cross-sectional view of the stirring device for cross-linking polymerization of polyvinyl chloride provided by the present invention. Figure 1 ; Figure 5 The povidone crosslinking polymerization stirring device provided by the present invention Figure 4 Enlarged structural diagram at point B; Figure 6 The povidone crosslinking polymerization stirring device provided by the present invention Figure 4 Enlarged structural diagram at point C; Figure 7 Schematic cross-sectional view of the stirring device for cross-linking polymerization of polyvinyl chloride provided by the present invention. Figure 2 ; Figure 8 The povidone crosslinking polymerization stirring device provided by the present invention Figure 7 Enlarged structural diagram at point D; Figure 9 A schematic diagram showing the disassembled structure of the servo motor, upper stirring shaft, and lower stirring shaft of the polyvinyl ketone crosslinking polymerization stirring device provided by the present invention; Figure 10 This is a cross-sectional view of the fan-shaped bag of the polyvinyl chloride crosslinking polymerization stirring device provided by the present invention.

[0020] In the diagram: 1. Housing; 11. Cooling water jacket; 12. Feeding funnel; 13. Feeding pipe; 14. Water inlet pipe; 15. Water outlet pipe; 2. Upper stirring shaft; 21. Upper stirring rod; 22. Upper annular ratchet part; 23. Strip-shaped limiting block; 3. Lower stirring shaft; 31. Lower stirring rod; 32. Lower annular ratchet part; 4. Cooling assembly; 41. Rotating shaft; 42. Fan-shaped bag; 421. Paraffin wax; 43. Torsion spring; 5. Drive assembly; 51. Servo motor; 52. Drive shaft; 521. Limiting groove; 6. Ratchet; 7. Pawl; 71. Telescopic rod; 72. Fixing block; 73. Spring; 74. Handle; 8. Elastic wear-resistant sleeve; 9. Sealing sleeve; 10. Controller. 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 1-10 As shown, the povidone crosslinking polymerization stirring device of the present invention includes a housing 1, a cooling water jacket 11 on the outer wall of the housing 1, an upper stirring shaft 2 movably connected to the upper end of the housing 1, a plurality of upper stirring rods 21 arranged in a circular array on the outer wall of the upper stirring shaft 2, and an upper annular ratchet portion 22 at the lower end of the upper stirring shaft 2. A lower stirring shaft 3 movably connected to the lower end of the housing 1, a plurality of lower stirring rods 31 arranged in a circular array on the outer wall of the lower stirring shaft 3, with the upper stirring rods 21 and the lower stirring rods 31 corresponding to each other in contact. The upper end of the lower stirring shaft 3 is provided with a part that corresponds to the upper annular ratchet portion 22. 2. Engaging lower annular ratchet portion 32; A cooling component 4 is provided between the upper stirring rod 21 and the lower stirring rod 31. The cooling component 4 includes a rotating shaft 41 rotatably connected to the side wall of the lower stirring rod 31 via a connecting block. A fan-shaped bag 42 is wound on the rotating shaft 41. The inside of the fan-shaped bag 42 is provided with a cavity, and the cavity is provided with solid paraffin wax 421. A torsion spring 43 is symmetrically provided on the rotating shaft 41, and the two ends of the torsion spring 43 are fixedly connected to the side wall of the lower stirring rod 31 and the rotating shaft 41, respectively. A drive component 5 for driving the upper stirring shaft 2 and the lower stirring shaft 3 to rotate is provided at the upper end of the housing 1.

[0023] Specifically, the drive assembly 5 includes a servo motor 51 mounted on the upper end of the housing 1 via a mounting bracket. The servo motor 51 is connected to a drive shaft 52 via a worm gear reducer, and the drive shaft 52 is movably inserted into an upper stirring shaft 2 with a hollow internal structure. Multiple strip-shaped limiting blocks 23 are arranged in a circular array on the inner wall of the upper stirring shaft 2, and multiple limiting grooves 521 are arranged in a circular array on the outer wall of the drive shaft 52. The strip-shaped limiting blocks 23 are correspondingly positioned within the limiting grooves 521. In the polyvinyl chloride crosslinking polymerization process, such as... Figure 4 and Figure 5 As shown, the servo motor 51 is started, which drives the drive shaft 52 to rotate clockwise. Due to the limiting effect of the strip-shaped limiting block 23 and the limiting groove 521, the upper stirring shaft 2 is driven to rotate clockwise in sync. Due to the meshing connection between the upper annular ratchet part 22 and the lower annular ratchet part 32, the lower stirring shaft 3 is driven to rotate synchronously in the same direction. The upper stirring rod 21 and the lower stirring rod 31 stir the material in the box 1, thereby increasing the efficiency of the polyvinyl chloride crosslinking polymerization reaction.

[0024] Specifically, the lower end of the lower stirring shaft 3 moves through the housing 1, and a ratchet 6 is fixedly connected to the end of the lower stirring shaft 3. A pawl 7 is engaged with the ratchet 6, and a telescopic rod 71 is fixedly connected to the other end of the pawl 7. The telescopic rod 71 is fixedly connected to a fixing block 72 set at the lower end of the housing 1, and a spring 73 that wraps around the telescopic rod 71 is fixedly connected between the pawl 7 and the fixing block 72. During the synchronous clockwise rotation of the lower stirring shaft 3, the pawl 7 reciprocates with the ratchet 6 under the action of the telescopic rod 71 and the spring 73, without affecting the rotation of the lower stirring shaft 3. When the polyvinyl chloride crosslinking polymerization reaction in the box 1 produces powder, the servo motor 51 rotates 90 degrees counterclockwise. Since the ratchet 6 is engaged and stuck on the ratchet 6, the ratchet 6 and the lower stirring shaft 3 cannot rotate counterclockwise. Consequently, the drive shaft 52 only drives the upper stirring shaft 2 to rotate counterclockwise, fully unfolding the fan-shaped bag 42. Through multiple fan-shaped bags 42 located inside the powder, the powder is cooled by the heat absorption and melting of the paraffin wax 421, thus preventing the powder from carbonizing.

[0025] Specifically, an elastic wear-resistant sleeve 8 is provided between the lower end of the mounting bracket and the upper end of the upper stirring shaft 2, and the elastic wear-resistant sleeve 8 is movably mounted on the drive shaft 52. During the counterclockwise rotation of the upper stirring shaft 2, the upper annular ratchet 22 will squeeze the lower annular ratchet 32, causing the upper annular ratchet 22 to rise slightly and squeeze the elastic wear-resistant sleeve 8. Furthermore, when the upper stirring shaft 2 rotates 90 degrees to fully open the fan-shaped bag 42, the upper annular ratchet 22 will re-engage with the lower annular ratchet 32 ​​under the elastic force of the elastic wear-resistant sleeve 8.

[0026] Specifically, a sealing sleeve 9 is bonded to the upper end of the lower stirring shaft 3, and the upper end of the sealing sleeve 9 covers the lower end of the upper stirring shaft 2. The sealing sleeve 9 seals and protects the upper annular ratchet portion 22 and the lower annular ratchet portion 32, preventing material from entering between the upper annular ratchet portion 22 and the lower annular ratchet portion 32 and affecting the transmission.

[0027] Specifically, the lower end of the pawl 7 is provided with a handle 74. After material discharge and internal rinsing of the box 1, by pulling the handle 74, the pawl 7 is disengaged from the ratchet 6, releasing the lock on the ratchet 6. Then, under the tension of the torsion spring 43, the friction and elasticity of the elastic wear-resistant sleeve 8 are overcome, and the lower stirring shaft 3 rotates 90 degrees counterclockwise. The drive shaft 52 is limited by the worm gear reducer and cannot rotate under friction, so that the fan-shaped bag 42 is rewound onto the rotating shaft 41 for the next polyvinyl chloride crosslinking polymerization stirring.

[0028] Specifically, the upper end of the housing 1 is provided with a feeding funnel 12, and the lower end of the housing 1 is provided with a feeding pipe 13. The feeding funnel 12 is used for adding materials; and a valve is installed on the feeding pipe 13 to feed the powder after the cross-linking polymerization reaction of polyvinyl ketone through the feeding pipe 13.

[0029] Specifically, the upper and lower ends of the outer wall of the housing 1 are provided with an inlet pipe 14 and an outlet pipe 15 that connect to the cooling water jacket 11; a controller 10 is provided on the outer wall of the housing 1, and the servo motor 51 is electrically connected to the controller 10. The controller 10 is used to control the start, stop and forward / reverse rotation of the servo motor 51.

[0030] Specifically, firstly, the power supply is connected and the servo motor 51 is started to run clockwise through the controller 10. After the worm gear reducer reduces the speed and increases the torque, it drives the drive shaft 52 to rotate clockwise. The limiting groove 521 on the outer wall of the drive shaft 52 is engaged with the strip-shaped limiting block 23 on the inner wall of the upper stirring shaft 2 to form a spline transmission structure that is circumferentially locked and axially sliding, thereby driving the upper stirring shaft 2 to rotate clockwise synchronously. The upper annular ratchet 22 at the lower end of the upper stirring shaft 2 is fully engaged with the lower annular ratchet 32 ​​at the upper end of the lower stirring shaft 3. The ratchet pair is in the transmission engagement state in the clockwise direction and in the slip disengagement state in the counterclockwise direction. Therefore, when rotating clockwise, the upper stirring shaft 2 drives the lower stirring shaft 3 to rotate synchronously and in the same direction through the ratchet engagement.

[0031] The ratchet 6 at the bottom of the housing 1 rotates clockwise synchronously with the lower stirring shaft 3. The pawl 7 slides back and forth along the tooth surface of the ratchet 6 under the support of the spring 73 and the telescopic rod 71, without constraining the rotation of the lower stirring shaft 3 and without interfering with the synchronous stirring action. Furthermore, the fan-shaped bag 42 of the cooling component 4 is rolled up on the rotating shaft 41 under the pre-tightening force of the torsion spring 43, and is stored in the gap between the closed stirring rods, without occupying additional stirring space or interfering with the stirring flow field of the liquid system. The system in this stage is liquid / paste-like, and the material has a strong convective heat transfer capacity. The heat generated by the reaction can be quickly transferred to the inner wall of the tank 1 through the material flow, and then carried away by the circulating cooling water in the outer wall cooling water jacket 11. The cooling water is introduced through the inlet pipe 14 and flows out through the outlet pipe 15, continuously maintaining a stable reaction temperature.

[0032] Then, through the transparent observation window (not shown in the figure) on the outer wall of the box 1, when the reaction enters the powder stage, the controller 10 controls the servo motor 51 to rotate 90 degrees counterclockwise; at this time, the pawl 7 is engaged in the tooth groove of the ratchet 6 under the push of the spring 73, and the ratchet and pawl pair is locked in the counterclockwise direction. The lower stirring shaft 3 is completely restricted from circumferential rotation and cannot rotate counterclockwise synchronously with the upper stirring shaft 2, forming a relative motion state of "the lower stirring shaft 3 is fixed and the upper stirring shaft 2 rotates alone".

[0033] During the unfolding process of the fan-shaped bag 42, the lower stirring shaft 3 remains stationary, while the upper stirring shaft 2 rotates counterclockwise independently under the drive of the drive shaft 52. The upper stirring rod 21 and the lower stirring rod 31, which were originally side by side, gradually develop a relative angle. The free end of the fan-shaped bag 42 is fixed to the side wall of the upper stirring rod 21, and the winding end is sleeved on the rotating shaft 41 of the lower stirring rod 31. As the angle between the two rods increases, the fan-shaped bag 42 is continuously pulled and unfolded. The rotating shaft 41 overcomes the elastic force of the torsion spring 43 and rotates synchronously. Finally, the fan-shaped bag 42 is fully unfolded into a fan-shaped sheet structure and is evenly inserted into the powder accumulation layer. During the relative rotation of the upper stirring shaft 2, the inclined surfaces of the upper annular ratchet 22 and the lower annular ratchet 32 ​​press against each other, generating an axial force that pushes the upper stirring shaft 2 to slide slightly upward along the drive shaft 52, compressing the elastic wear-resistant sleeve 8 at the top to provide clearance for the ratchet to "climb"; when the upper stirring shaft 2 rotates 90 degrees and the fan-shaped bag 42 is fully unfolded, the ratchet falls back into the tooth groove under the rebound thrust of the elastic wear-resistant sleeve 8 to complete the meshing, ensuring the circumferential stability of the stirring structure. The sealing sleeve 9 at the upper end of the lower stirring shaft 3 always covers the meshing area of ​​the upper and lower ratchets, preventing powder materials from entering the tooth surface gap and avoiding material jamming that could cause transmission failure and accelerated wear.

[0034] During the paraffin phase change cooling process, the unfolded fan-shaped bag 42 is directly immersed in the powder accumulation layer. The solid paraffin 421 encapsulated inside the bag exchanges heat with the high-temperature powder through the bag wall. When the internal temperature of the powder rises to the phase change temperature of paraffin 421 (48~52℃), the solid paraffin begins to transform from solid to liquid. It continuously absorbs the polymerization reaction heat inside the powder by utilizing the latent heat of solid-liquid phase change of about 210J / g. During the melting process, the temperature of the paraffin remains basically constant, which can clamp the temperature of the surrounding powder below the product degradation threshold, thus avoiding abnormal cross-linking, decreased swelling performance, and carbonization black spots caused by excessively high local temperatures. Compared with traditional external jacket heat exchange, the fan-shaped bag 42 arranges the heat exchange surface directly in the core area of ​​the powder, shortening the heat exchange path from "powder accumulation layer → vessel wall → cooling water" to "powder → bag wall → paraffin", completely eliminating the low thermal resistance of the powder accumulation layer.

[0035] Finally, after the polymerization reaction is completed, open the valve of the feed pipe 13 to discharge the finished powder and clean the inside of the box 1; then manually pull the handle 74 at the lower end of the pawl 7 to overcome the elastic force of the spring 73 and drive the pawl 7 outward to disengage from the tooth groove of the ratchet 6, thereby releasing the rotation lock on the lower stirring shaft 3.

[0036] After the lock is released, the rotating shaft 41 rotates in the opposite direction under the rebound force of the torsion spring 43, rewinding the fan-shaped bag 42 onto the rotating shaft 41. During the winding process, the fan-shaped bag 42 pulls the upper stirring rod 21 to rotate relative to the lower stirring rod 31, causing the lower stirring shaft 3 to rotate 90 degrees counterclockwise synchronously, so that the upper stirring rod 21 and the lower stirring rod 31 are restored to their aligned state. Since the worm gear reducer connected to the upper end of the drive shaft 52 has a reverse self-locking characteristic, the drive shaft 52 will not rotate with the rotation of the lower stirring shaft 3. The reset process only involves the lower stirring shaft 3 resetting by idling, without affecting the state of the drive end. After the reset is completed, the device returns to its initial state, and the feeding funnel 12 can be used to feed the next batch of reaction materials, directly entering the next production cycle.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A stirring device for crosslinking polymerization of polyvinyl chloride, comprising a housing (1), wherein a cooling water jacket (11) is provided on the outer wall of the housing (1), characterized in that: The upper end of the box (1) is movably connected to an upper stirring shaft (2). Multiple upper stirring rods (21) are arranged in a circular array on the outer wall of the upper stirring shaft (2). The lower end of the upper stirring shaft (2) is provided with an upper annular ratchet part (22). The lower end of the box (1) is movably connected to a lower stirring shaft (3). Multiple lower stirring rods (31) are arranged in a circular array on the outer wall of the lower stirring shaft (3). The upper stirring rods (21) and the lower stirring rods (31) are arranged in a one-to-one correspondence. The upper end of the lower stirring shaft (3) is provided with a lower annular ratchet part (32) that meshes with the upper annular ratchet part (22). A cooling assembly (4) is provided between the upper stirring rod (21) and the lower stirring rod (31). The cooling assembly (4) includes a rotating shaft (41) rotatably connected to the side wall of the lower stirring rod (31) via a connecting block. A fan-shaped bag (42) is wound on the rotating shaft (41). The fan-shaped bag (42) has a cavity inside, and the cavity contains solid paraffin wax (421). Torsion springs (43) are symmetrically provided on the rotating shaft (41), and the two ends of the torsion springs (43) are fixedly connected to the side wall of the lower stirring rod (31) and the rotating shaft (41) respectively. The upper end of the housing (1) is provided with a drive assembly (5) for driving the upper stirring shaft (2) and the lower stirring shaft (3) to rotate.

2. The polyvinyl chloride crosslinking polymerization stirring device according to claim 1, characterized in that: The drive assembly (5) includes a servo motor (51) mounted on the upper end of the housing (1) via a mounting bracket. The servo motor (51) is connected to a drive shaft (52) via a worm gear reducer. The drive shaft (52) is movably inserted into an upper stirring shaft (2) with a hollow internal structure. Multiple strip-shaped limiting blocks (23) are arranged in a circular array on the inner wall of the upper stirring shaft (2). Multiple limiting grooves (521) are arranged in a circular array on the outer wall of the drive shaft (52). The strip-shaped limiting blocks (23) are correspondingly arranged in the limiting grooves (521).

3. The polyvinyl chloride crosslinking polymerization stirring device according to claim 1, characterized in that: The lower end of the lower stirring shaft (3) moves through the box (1), and a ratchet (6) is fixedly connected to the end of the lower stirring shaft (3). A pawl (7) is engaged on the ratchet (6), and a telescopic rod (71) is fixedly connected to the other end of the pawl (7). The telescopic rod (71) is fixedly connected to a fixing block (72) at the lower end of the box (1), and a spring (73) that wraps around the telescopic rod (71) is fixedly connected between the pawl (7) and the fixing block (72).

4. The polyvinyl ketone crosslinking polymerization stirring device according to claim 2, characterized in that: The lower end of the mounting bracket is provided with an elastic wear-resistant sleeve (8) between the upper end of the upper stirring shaft (2) and the upper end of the mounting bracket. The elastic wear-resistant sleeve (8) is movably mounted on the drive shaft (52).

5. The polyvinyl ketone crosslinking polymerization stirring device according to claim 1, characterized in that: The upper end of the lower stirring shaft (3) is bonded with a sealing sleeve (9), and the upper end of the sealing sleeve (9) wraps around the lower end of the upper stirring shaft (2).

6. The polyvinyl chloride crosslinking polymerization stirring device according to claim 3, characterized in that: The pawl (7) has a handle (74) at its lower end.

7. The polyvinyl ketone crosslinking polymerization stirring device according to claim 1, characterized in that: The upper end of the box (1) is provided with a feeding funnel (12), and the lower end of the box (1) is provided with a feeding pipe (13).

8. The polyvinyl chloride crosslinking polymerization stirring device according to claim 1, characterized in that: The upper and lower ends of the outer wall of the box (1) are provided with an inlet pipe (14) and an outlet pipe (15) that connect to the cooling water jacket (11).

9. The polyvinyl chloride crosslinking polymerization stirring device according to claim 2, characterized in that: The outer wall of the housing (1) is provided with a controller (10), and the servo motor (51) is electrically connected to the controller (10).

Images