Apparatus and method for the production of low mooney tetrapropylene fluoroelastomer based on a tubular reactor

Abstract

This invention discloses a device and method for preparing low Mooney PTFE rubber based on a tubular reactor, belonging to the field of rubber preparation technology. The device for preparing low Mooney PTFE rubber based on a tubular reactor includes two supports and a reaction tube disposed between the two supports. The reaction tube includes: a first support body, fixedly connected to one of the supports, with a driving structure inside; a tail support body, fixedly connected to the other support, with a rotating rod driven by the driving structure rotatably disposed between the tail support body and the first support body; and a movable tube, rotatably disposed between the first and tail supports. This invention achieves a continuous, uniform, and controllable polymerization reaction through a combination of the rotation of the movable tube and the axial reciprocating motion of the spiral scraper, combined with efficient dynamic heat exchange. This solves the technical problems existing in the preparation of PTFE rubber using traditional reactors, such as uneven mixing, low heat transfer efficiency, easy wall adhesion and delamination, and large batch-to-batch differences.

Description

Technical Field

[0001] This invention relates to the field of rubber preparation technology, and in particular to an apparatus and method for preparing low Mooney tetrafluoroethylene rubber based on a tubular reactor. Background Technology

[0002] Tetrafluoropropylene rubber (Teflon) is a polymer material with excellent high-temperature resistance, chemical resistance, and steam resistance, and is widely used in high-end fields such as automotive, aerospace, and petrochemicals. Mooney viscosity is a key indicator for measuring its raw rubber processing performance; lower Mooney viscosity means better flowability and easier subsequent mixing, extrusion, and molding.

[0003] Currently, the industrial production of tetrafluoropropylene rubber (Teflon) mostly employs batch reactors. This process has several inherent drawbacks: First, uneven mixing of materials within the reactor easily leads to localized reaction hotspots and concentration gradients, resulting in an excessively wide polymer molecular weight distribution, causing high and fluctuating Mooney viscosity and poor product stability. Second, the polymerization reaction is highly exothermic, and the batch reactor has a small surface area and low heat transfer efficiency, making it difficult to quickly and uniformly remove the heat of reaction. The lag and fluctuation in temperature control affect the regularity of the polymer molecular chains, further increasing the Mooney viscosity. Third, batch-to-batch variations in batch production make it difficult to guarantee product consistency.

[0004] To overcome the shortcomings of intermittent production, continuous tubular reactors are considered a promising alternative. However, their direct application to high-viscosity rubber polymerization systems faces significant challenges: Firstly, as polymerization proceeds, the material viscosity rises sharply, easily adhering to the tube wall to form an insulating layer. Due to gravity, the material accumulates in the lower half of the tube, while a gas phase space easily forms in the upper part, leading to a sharp drop in heat transfer efficiency and frequent localized overheating (hot spots), severely impacting product quality. Secondly, the parabolic flow pattern within traditional tubular reactors results in severe backmixing, causing a wide distribution of material residence time, which is also unfavorable for obtaining low Mooney viscosity products with uniform molecular weight distribution. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art, and to propose an apparatus and method for preparing low Mooney tetrafluoroethylene rubber based on a tubular reactor.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An apparatus for preparing low Mooney tetrafluoropropylene rubber based on a tubular reactor includes two supports and a reaction tube disposed between the two supports, the reaction tube comprising:

[0008] The first seat body is fixedly connected to one of the supports and has a driving structure inside it;

[0009] The tailstock body is fixedly connected to another support, and a rotating rod driven by a driving structure is rotatably provided between the tailstock body and the headstock body.

[0010] A movable tube, which is rotatably disposed between the first seat body and the tail seat body, is used for the reaction and mixing of materials;

[0011] The inlet and outlet structure is located at both ends of the movable tube and is used for material to enter and exit the reaction tube;

[0012] The rotating rod is equipped with a scraping component for assisting in the mixing of materials.

[0013] Preferably, the first seat body includes a main body fixedly connected to one of the supports, a connecting ring fixedly connected to the main body, and a connecting plate fixedly connected to the connecting ring. The rotating rod is rotatably mounted on the connecting plate, and the inner side wall of the movable tube is rotatably mounted to the outer side wall of the connecting plate.

[0014] The drive structure includes a drive motor fixed on the main body, a drive rod fixedly connected to the output shaft of the drive motor, a drive gear set on the drive rod, a movable gear rotatably set between the main body and the connecting plate via a rotating shaft, and a driven gear fixed on the inner wall of the movable tube and meshing with the movable gear. One end of the rotating rod is fixedly connected to the end of the drive rod away from the drive motor.

[0015] Preferably, the scraping assembly includes a connector mounted on a rotating rod and a spiral blade connected to the end of the connector away from the rotating rod. The edge of the spiral blade is provided with a rubber scraper that moves against the inner wall of the movable tube.

[0016] Preferably, the connecting member includes a fixed rod connected to the rotating rod, a collar disposed at the end of the fixed rod, and a connecting rod fixedly connected to the collar, wherein the end of the connecting rod away from the collar is fixedly connected to the helical blade;

[0017] A guide rod is fixed between the connecting plate and the tailstock body, and the collar is slidably connected to the guide rod;

[0018] The outer wall of the rotating rod is provided with a spiral track groove, and a slider that is fixedly connected to the fixed rod is slidably connected in the spiral track groove. The inner wall of the spiral track groove is provided with an arc surface with the opening facing outward.

[0019] Preferably, the feeding and discharging structure includes a feeding assembly and a discharging assembly. The feeding assembly includes a feeding ring disposed on a support connected to one end of the first seat body and a feeding port fixed on the feeding ring. One end of the movable tube is provided with a feeding groove that cooperates with the feeding port. The discharging assembly includes a discharging ring disposed on a support connected to one end of the tail seat body and a discharging port fixed on the discharging ring. The other end of the movable tube is provided with a discharging groove that cooperates with the discharging port.

[0020] Preferably, a sleeve is fixed between the feed ring and the discharge ring, and a temperature regulating cavity for the flow of heat-conducting liquid is formed between the inner wall of the sleeve and the outer wall of the movable tube. The feed ring has an inlet hole that communicates with the temperature regulating cavity, and the discharge ring has an outlet hole that communicates with the temperature regulating cavity.

[0021] Preferably, a rotating shaft is rotatably arranged inside the temperature regulating cavity, and a plurality of material-pulling blades are arranged on the rotating shaft;

[0022] One end of the rotating shaft passes through the feed ring and the support connected thereto, and is connected to a first synchronous pulley. The output shaft of the drive motor is connected to a second synchronous pulley, and a synchronous belt is provided between the first synchronous pulley and the second synchronous pulley.

[0023] Preferably, a movable tube is slidably connected to the outer side of the rotating shaft, and a push rod is provided at both ends of the movable tube. A ball bearing is provided at the end of the push rod. An abutment block is provided on the outer wall of the feeding ring and the discharging ring of the temperature regulating chamber. An extrusion slope with parallel inclined surfaces is provided on the two abutment blocks. A number of guide plates inclined towards the inner wall of the sleeve and the outer wall of the movable tube are provided on the movable tube.

[0024] Preferably, the feeding plate is rotatably mounted on a rotating shaft via a pin, and a hinge plate is movably arranged between the moving tube and the feeding plate.

[0025] This invention also discloses a method for preparing low Mooney tetrafluoropropylene rubber based on a tubular reactor, which is carried out using the aforementioned tubular reactor-based low Mooney tetrafluoropropylene rubber preparation apparatus, and includes the following steps:

[0026] S1: Heat-conducting liquid at a predetermined temperature is introduced into the temperature-regulating chamber through the liquid inlet hole and flows out from the liquid outlet hole to form a circulation;

[0027] Start the drive motor and run it under no-load for a while to confirm that the moving tube, rotating rod, spiral blades and the stirring mechanism in the temperature control chamber are running smoothly and without jamming.

[0028] S2: The prepared reaction materials are continuously fed into the device from the feed port through a metering pump, while the drive motor is kept running.

[0029] S3: The material moves forward inside the moving tube, and the rotating rod rotates under the drive of the drive motor;

[0030] Since the slider is embedded in the spiral track groove of the rotating rod, when the rotating rod rotates, the slider is forced to slide along the track groove, thereby driving the entire connecting piece and the spiral blade to make axial reciprocating motion along the guide rod;

[0031] The drive gear on the drive rod drives the movable gear, which in turn meshes with and drives the driven gear fixed to the inner wall of the movable tube, thereby causing the movable tube to rotate slowly around its axis.

[0032] The combined motion of the spiral blades reciprocating axially relative to the guide rod and rotating relative to the movable tube mixes the materials and scrapes the inner wall, preventing material stratification.

[0033] S4: When the drive rod rotates, it drives the rotating shaft and the feeding plate to rotate in the temperature control chamber through the synchronous belt and synchronous pulley. When the rotating shaft rotates, it drives the moving tube to rotate synchronously. The balls at the ends of the push rods at both ends of the moving tube roll on the extrusion inclined surface fixed to the abutment block. Due to the inclined surface, the moving tube will generate axial reciprocating motion while rotating. The moving tube pushes the feeding plate through the hinge plate, causing it to swing around the pin shaft. This adds angular swing on the basis of rotation and stirring, forming turbulence in the whole area without dead zones, ensuring that the reaction heat is carried away in time.

[0034] The guide plate on the moving tube moves with it, continuously guiding the heat-conducting liquid in the middle of the temperature-regulating cavity to the inner wall of the sleeve and the outer wall of the moving tube, directly flushing the boundary layer that may be formed, and enhancing the heat transfer at the wall surface.

[0035] S5: The low Mooney tetrafluoropropylene rubber compound that has completed the reaction is continuously discharged from the outlet;

[0036] By adjusting the speed of the drive motor, the material residence time and mixing intensity can be changed;

[0037] The reaction temperature is precisely controlled by adjusting the temperature and flow rate of the heat-conducting liquid;

[0038] S6: Finally, stop feeding, wait for the material in the pipe to be emptied, then introduce solvent for cleaning, and then stop the drive motor and temperature control system.

[0039] Compared with the prior art, the present invention provides an apparatus and method for preparing low Mooney tetrafluoroethylene rubber based on a tubular reactor, which has the following beneficial effects:

[0040] 1. In this invention, the movable tube rotates under gear drive, while the helical blades with scrapers rotate and reciprocate axially under the drive of the rotating rod and helical track groove, applying an extremely strong shear and tensile flow field to the material. This ensures uniform mixing and reaction of the reaction components at the microscale, effectively narrowing the molecular weight distribution of the polymer and avoiding irregular growth of molecular chains caused by local overheating. As a result, tetrafluoroethylene propylene rubber with significantly reduced Mooney viscosity and regular molecular structure is stably prepared, ensuring product quality. Compared with traditional batch reactors, this invention increases production efficiency by more than 40%, reduces the product Mooney viscosity fluctuation range by 60%, and reduces the frequency of wall cleaning by 80%.

[0041] 2. In this invention, a continuous material reaction channel is formed by the inlet, the moving tube and the outlet. The material continuously enters from the inlet, completes the reaction in the moving tube and is continuously discharged from the outlet, realizing true continuous production. This structure completely eliminates the batch interval inherent in intermittent operation. For large-scale production, continuous production brings many benefits such as increased output, reduced energy consumption and labor saving.

[0042] 3. In this invention, an active enhanced heat transfer system is constructed from the inside out. Inside, the rotating moving tube and reciprocating scraper work together to completely destroy the thermal boundary layer on the material side. In the outer jacket (temperature control chamber), the rotating shaft driven by the synchronous belt drives the material-pushing blade to rotate, generating basic agitation. At the same time, through the cooperation of the push rod and the extrusion inclined surface, the moving tube drives the guide plate to move axially and pushes the material-pushing blade to swing, realizing variable angle, full-domain turbulent agitation and active wall scouring of the heat transfer fluid. This reduces the thermal resistance on both the material side and the heat transfer fluid side to extremely low levels, doubles the heat transfer efficiency, and can remove the reaction heat in a timely and uniform manner, achieving precise control of the reaction temperature and fundamentally eliminating local overheating. This provides a crucial guarantee for obtaining low Mooney viscosity products.

[0043] 4. In this invention, the rubber scraper at the end of the spiral blade dynamically scrapes the inner wall of the moving tube without dead angles through a combination of rotation and reciprocating motion, keeping the inner wall clean at all times and ensuring heat transfer efficiency. Secondly, the rotation of the moving tube itself ensures that no area of ​​its circumference remains at the bottom. Combined with the vigorous stirring of the spiral blade, the tendency of materials to settle and stratify due to gravity is completely destroyed, ensuring that the entire reaction space is uniformly filled with materials, achieving no stagnation zone in the reactor. All materials experience the same thermal and shear history, with an extremely narrow residence time distribution and extremely high reaction uniformity, thereby ensuring the uniformity and stability of product quality. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0045] Figure 2This is a cross-sectional structural diagram of the present invention;

[0046] Figure 3 for Figure 2 Enlarged structural diagram of section A in the middle;

[0047] Figure 4 for Figure 2 Enlarged structural diagram of section B;

[0048] Figure 5 This is a schematic diagram of the separation structure of the support and reaction tube of the present invention;

[0049] Figure 6 This is a schematic cross-sectional view of the end of the reaction tube of the present invention;

[0050] Figure 7 for Figure 6 Enlarged structural diagram of section C;

[0051] Figure 8 for Figure 6 Enlarged structural diagram of section D in the middle;

[0052] Figure 9 This is a schematic diagram of the cross-sectional structure of the first body of the present invention;

[0053] Figure 10 This is a schematic diagram of the connector of the present invention;

[0054] Figure 11 This is a schematic diagram of the external structure of the rotating shaft of the present invention;

[0055] Figure 12 This is a schematic diagram of the structure of the push rod and the abutment block of the present invention.

[0056] In the diagram: 1. Support; 2. Reaction tube; 201. First seat body; 2011. Main body; 2012. Connecting ring; 2013. Connecting plate; 202. Tail seat body; 203. Movable tube; 2031. Feed trough; 2032. Discharge trough; 3. Rotating rod; 4. Feeding ring; 401. Feed inlet; 402. Liquid inlet; 5. Discharge ring; 501. Discharge outlet; 502. Liquid outlet; 6. Drive motor; 601. Drive rod; 602. Drive gear; 603. Movable... 604 Driven gear; 7 Connector; 701 Fixed rod; 702 Collar; 703 Connecting rod; 704 Guide rod; 8 Helical blade; 801 Rubber scraper; 9 Helical track groove; 10 Sleeve; 1001 Temperature regulating chamber; 11 Rotating shaft; 111 Material feeding plate; 12 Synchronous belt; 13 Moving tube; 131 Push rod; 1311 Ball bearing; 132 Guide plate; 14 Abutting block; 141 Extrusion inclined surface; 15 Hinge plate. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0058] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0059] like Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, this embodiment proposes a preparation apparatus for low Mooney tetrafluoroethylene rubber based on a tubular reactor, including two supports 1 and a reaction tube 2 disposed between the two supports 1. The reaction tube 2 includes: a first support body 201, a last support body 202, a movable tube 203, and an inlet / outlet structure. The first support body 201 and the last support body 202 are respectively fixed on the two supports 1, forming the static end cap structure of the reaction tube 2. The movable tube 203 serves as the main reaction vessel, and its two ends are rotatably supported between the first support body 201 and the last support body 202 through bearings or sealed rotary joints, etc., so that the movable tube 203 can be rotatably supported between the first support body 201 and the last support body 202. The tube 203 can rotate around its own axis; the first seat 201 is fixedly connected to one of the supports 1, and a driving structure is provided inside it; the tail seat 202 is fixedly connected to the other support 1, and a rotating rod 3 driven by the driving structure is rotatably arranged between the tail seat 202 and the first seat 201; the movable tube 203 is rotatably arranged between the first seat 201 and the tail seat 202 for the reaction mixing between materials; the inlet and outlet structures are arranged at both ends of the movable tube 203 for the material to enter and exit the reaction tube 2; wherein, a scraping component for assisting material mixing is provided on the rotating rod 3;

[0060] Specifically, the drive structure located at the first body 201 is activated, which drives the rotating rod 3 to rotate. Subsequently, the reactants, such as tetrafluoroethylene, propylene monomer, solvent, initiator, etc., are continuously pumped into the moving tube 203 through the inlet / outlet structure at one end. The materials move from the inlet end to the outlet end within the moving tube 203. During this process, the high-speed rotating rod 3 drives the scraping component on it to strongly stir and shear the materials, ensuring thorough mixing and polymerization. At the same time, the moving tube 203 itself begins to slowly rotate around the rotating rod 3 under the indirect or direct drive of the drive structure. The rotation of the moving tube 203 causes its inner wall to no longer be in a fixed position. While the scraping component rotates and stirs the materials, it generates relative motion with the rotating inner wall, thereby effectively scraping or disturbing the materials that may adhere to the inner wall and preventing scaling. The combination of "moving wall" and "moving paddle" ensures that the materials are heated and the degree of reaction is highly uniform. After the reaction is completed, the generated adhesive is continuously discharged from the inlet / outlet structure at the other end, achieving uninterrupted production.

[0061] The rotating rod 3 drives the scraping assembly to rotate at high speed in the moving tube 203, generating strong shearing and mixing action on the material, ensuring the uniformity of the reaction components, laying the foundation for obtaining polymers with narrow molecular weight distribution and regular structure. At the same time, the setting of the feeding and discharging structure allows the material to be fed and discharged continuously, upgrading the batch batch reactor reaction to a continuous tubular reaction, significantly improving production efficiency and eliminating batch-to-batch quality differences.

[0062] The rotation of the movable tube 203 drives the movement of the entire material bed inside it, breaking the tendency of the material to settle or stratify due to gravity, such as the stratification phenomenon of high viscosity material at the bottom and gas phase at the top. This allows the entire circumferential wall of the movable tube 203 to participate in heat exchange equally, and the material temperature and concentration distribution above and below the tube cross-section is more uniform. This ensures that all materials have similar reaction residence time and thermal history, and the Mooney viscosity and other indicators of the final product are more uniform and stable.

[0063] like Figure 1 , Figure 2 , Figure 3 , Figure 6 , Figure 7 and Figure 9As shown, in a preferred embodiment, based on the above method, the first seat body 201 further includes a main body 2011 fixedly connected to one of the supports 1, a connecting ring 2012 fixedly connected to the main body 2011, and a connecting plate 2013 fixedly connected to the connecting ring 2012. The main body 2011 is used to fix to the support 1 and provide main support, the connecting ring 2012 plays a connecting and spatial transition role, and the connecting plate 2013 serves as the mounting base for the internal core components; the rotating rod 3 is rotatably mounted on the connecting plate 2013, and the inner side wall of the movable tube 203 is rotatably mounted to the outer side wall of the connecting plate 2013.

[0064] The drive structure includes a drive motor 6 fixed on the main board 2011, a drive rod 601 fixedly connected to the output shaft of the drive motor 6, a drive gear 602 set on the drive rod 601, a movable gear 603 rotatably set between the main board 2011 and the connecting plate 2013 via a rotating shaft, and a driven gear 604 fixed on the inner wall of the movable tube 203 and meshing with the movable gear 603. One end of the rotating rod 3 is fixedly connected to the end of the drive rod 601 away from the drive motor 6.

[0065] Specifically, when the drive motor 6 is started, its output shaft directly drives the drive rod 601 to rotate synchronously. Since the rotating rod 3 is fixedly connected to the end of the drive rod 601, the rotation of the drive rod 601 directly drives the rotating rod 3 to rotate at the same speed, thereby driving the scraping component on it to work. At the same time, the drive rod 601 drives the drive gear 602 on it to rotate. The drive gear 602 transmits power to the movable gear 603 that meshes with it. The movable gear 603 then transmits power to the driven gear 604 that meshes with it and is fixed on the inner wall of the movable tube 203. Through the transmission of this gear pair, the power is transmitted to the movable tube 203, causing it to start rotating around its own axis. By adjusting the speed of the drive motor 6, the mixing requirements of materials with different viscosities can be adapted.

[0066] The rotation of the rotating rod 3 and the movable tube 203 are achieved by a single drive motor 6, making the device structure very compact, reducing external transmission components, lowering the complexity and manufacturing cost of the equipment, while ensuring the efficiency and reliability of power transmission. The speed ratio between the two is determined by the gear ratio of the drive gear 602, the movable gear 603 and the driven gear 604, forming a fixed motion relationship. This avoids the control asynchrony problem that may occur when using two independent motors, and provides a fundamental guarantee for the repeatability of the reaction process and the stability of product quality.

[0067] like Figure 2 , Figure 3 , Figure 6 , Figure 9 and Figure 10As shown, in a preferred embodiment, based on the above method, the scraping assembly further includes a connector 7 disposed on the rotating rod 3 and a spiral blade 8 connected to the end of the connector 7 away from the rotating rod 3. The edge of the spiral blade 8 is provided with a rubber scraper 801 that moves against the inner wall of the movable tube 203. The rubber scraper 801 is provided so that it always keeps in contact with the tube wall during rotation, but the contact is flexible and non-rigid. The scraper material should be a high-temperature resistant and solvent-resistant elastic material, such as high-performance perfluoroether rubber.

[0068] Furthermore, the connecting member 7 includes a fixed rod 701 connected to the rotating rod 3, a collar 702 disposed at the end of the fixed rod 701, and a connecting rod 703 fixedly connected to the collar 702. The end of the connecting rod 703 away from the collar 702 is fixedly connected to the spiral blade 8.

[0069] A guide rod 704 is fixed between the connecting plate 2013 and the tailstock body 202. The collar 702 is slidably connected to the guide rod 704, allowing the entire connecting piece 7 and the spiral blade 8 to slide axially under the constraint of the guide rod 704, but not to rotate.

[0070] The outer wall of the rotating rod 3 is provided with a spiral track groove 9. A slider that is fixedly connected to the fixed rod 701 is slidably connected in the spiral track groove 9. The inner wall of the spiral track groove 9 is provided with an arc surface with the opening facing outward. The arc surface allows the material entering the spiral track groove 9 to slide out of the groove smoothly when pushed by the slider, instead of being squeezed and stuck. Structurally, this greatly reduces the risk of slag accumulation and jamming, avoids hindering the stable operation of the connecting part 7. At the same time, the arc surface reduces the contact stress between the slider and the groove wall, reduces the risk of wear and jamming, and improves the service life and smoothness of the mechanism.

[0071] Specifically, the drive structure drives the rotating rod 3 to rotate around its axis. Since the slider is embedded in the fixed spiral track groove 9, when the rotating rod 3 rotates, the groove wall of the spiral track groove 9 will exert a force on the slider. Since the slider is restricted by the guide rod 704 through the fixed rod 701 and the collar 702 and cannot rotate, this force forces the slider to drive the entire connecting piece 7 to make axial reciprocating motion along the guide rod 704. The axial motion of the connecting piece 7 drives the spiral blade 8 at its end to make synchronous axial reciprocating motion. At the same time, since the drive structure drives the movable tube 203 to rotate through the meshing between gears, the rubber scraper 801, under the combined action of the rotation of the movable tube 203 and its own axial reciprocating motion, thoroughly scrapes the inner wall of the movable tube 203. This allows the relatively compact spiral blade 8 to cover the entire inner wall length of the movable tube 203 through axial movement, achieving continuous, dynamic, and dead-angle-free cleaning of the tube wall. This fundamentally prevents the formation of wall adhesion and insulation layers, and its cleaning effect is far superior to that of a scraper that only makes rotational motion.

[0072] The axial reciprocating motion of the spiral blade 8 not only has a rotational shearing effect on the material, but also produces a strong axial folding and stretching effect. The complex flow field can effectively break up material clumps, promote micro-mixing, and ensure uniform reaction. At the same time, the reciprocating motion can continuously disturb the low-speed zone or dead zone near the pipe wall, completely preventing the retention of high-viscosity materials in any part, ensuring that all materials have similar reaction times, thereby ensuring the processing effect.

[0073] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, in a preferred embodiment, based on the above method, the feeding and discharging structure further includes a feeding assembly and a discharging assembly. The feeding assembly includes a feeding ring 4 disposed on a support 1 connected to one end of the first seat body 201 and a feeding port 401 fixed on the feeding ring 4. One end of the movable tube 203 is provided with a feeding groove 2031 that cooperates with the feeding port 401. The discharging assembly includes a discharging ring 5 disposed on a support 1 connected to one end of the tail seat body 202 and a discharging port 501 fixed on the discharging ring 5. The other end of the movable tube 203 is provided with a discharging groove 2032 that cooperates with the discharging port 501.

[0074] Specifically, reactants such as monomers and solvents are continuously pumped into a fixed inlet 401 via an external conveying system such as a metering pump. After passing through the inlet 401, the material enters the feed trough 2031, which is connected to the inlet 401 and located at the end of the rotating movable tube 203, thus smoothly entering the internal reaction chamber of the movable tube 203. The material undergoes a polymerization reaction inside the movable tube 203 and moves from the feed end to the discharge end under its own pressure. After the reaction is completed, the resin reaches the discharge end of the movable tube 203 and flows out through the discharge trough 2032 at its end, entering a fixed discharge port 501. Finally, it is continuously discharged through the discharge port 501 and enters the subsequent processing steps.

[0075] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6 and Figure 8 As shown, in a preferred embodiment, based on the above method, a sleeve 10 is fixed between the feed ring 4 and the discharge ring 5. A temperature regulating cavity 1001 for the flow of heat-conducting liquid is formed between the inner wall of the sleeve 10 and the outer wall of the movable tube 203. The feed ring 4 is provided with a liquid inlet hole 402 that communicates with the temperature regulating cavity 1001, and the discharge ring 5 is provided with a liquid outlet hole 502 that communicates with the temperature regulating cavity 1001.

[0076] Specifically, the heat transfer fluid from external temperature control equipment such as a mold temperature controller can be heat transfer oil. It is pumped into the temperature control chamber 1001 through the inlet port 402 via a pipeline. The heat transfer fluid fills the temperature control chamber 1001 and flows within it, exchanging heat fully with the outer wall of the movable tube 203, which serves as the inner wall of the reactor. If the reaction is exothermic, the heat transfer fluid absorbs heat and cools the reaction zone. If heating is required, high-temperature heat transfer fluid is introduced to heat the reaction zone. After completing the heat exchange, the heat transfer fluid flows out from the other end of the temperature control chamber 1001 through the outlet port 502 and returns to the external temperature control equipment for temperature regulation, thus forming a continuous circulation loop.

[0077] like Figure 6 , Figure 8 and Figure 11 As shown, in a preferred embodiment, based on the above method, a rotating shaft 11 is rotatably arranged inside the temperature regulating cavity 1001, and a plurality of material-pulling plates 111 are arranged on the rotating shaft 11.

[0078] One end of the rotating shaft 11 passes through the feed ring 4 and the support 1 connected thereto and is connected to the first synchronous pulley. The output shaft of the drive motor 6 is connected to the second synchronous pulley. A synchronous belt 12 is provided between the first synchronous pulley and the second synchronous pulley. The mechanical synchronous belt 12 transmission ensures that the rotational speed between the internal stirring and the external liquid stirring is kept in a strict fixed ratio, realizing the synchronization of the two systems and contributing to the stability and coordination of the entire reaction system.

[0079] Specifically, when the drive motor 6 starts, its output shaft drives the second synchronous pulley to rotate. The second synchronous pulley transmits power to the first synchronous pulley via the synchronous belt 12. The first synchronous pulley drives the rotating shaft 11 to rotate synchronously. Multiple feed plates 111 on the rotating shaft 11 then rotate within the temperature control chamber 1001, generating strong agitation, shearing, and pumping effects on the heat-conducting liquid within the chamber. This effectively breaks down the laminar boundary layer that may form during the flow of the heat-conducting liquid, especially effectively eliminating the "stagnant zone" or "dead zone" formed near the outer wall of the reaction tube 2 and the inner wall of the sleeve 10 due to low liquid flow velocity. The heat-conducting liquid is always in a highly turbulent state, which greatly improves the convective heat transfer coefficient between the liquid and the outer wall of the moving tube 203. This ensures that the heat generated by the reaction can be removed in a timely, efficient and uniform manner, fundamentally eliminating the problem of local overheating of the reaction tube 2 due to poor heat transfer. This provides a crucial temperature guarantee for the preparation of tetrafluoroethylene rubber with regular structure and low and uniform Mooney viscosity. At the same time, stirring also accelerates the mixing rate of the heat-conducting liquid itself. When heat-conducting liquids of different temperatures are introduced, their temperature can be quickly homogenized, thereby improving the response speed of the entire temperature control system to changes in the heat of reaction.

[0080] like Figure 2 , Figure 6 , Figure 8 , Figure 11 and Figure 12 As shown, in a preferred embodiment, based on the above method, a moving tube 13 is further slidably connected to the outer side of the rotating shaft 11. Both ends of the moving tube 13 are provided with push rods 131, and the ends of the push rods 131 are provided with balls 1311. The provision of balls 1311 reduces wear during movement. The temperature regulating chamber 1001 is provided with abutment blocks 14 on the outer walls of the feed ring 4 and the discharge ring 5. The two abutment blocks 14 are provided with parallel inclined extrusion slopes 141. The moving tube 13 is provided with several guide plates 132 inclined towards the inner wall of the sleeve 10 and the outer wall of the movable tube 203. The purely mechanical linkage makes the power transmission direct, the response speed strictly synchronized with the spindle speed, and the operation reliable. It can automatically adjust the stirring intensity according to the host speed without adding additional control, thus achieving a unity of high efficiency and high reliability.

[0081] Furthermore, the material feeding plate 111 is rotatably mounted on the rotating shaft 11 via a pin, and a hinge plate 15 is movably arranged between the moving tube 13 and the material feeding plate 111.

[0082] Specifically, the drive motor 6 drives the rotating shaft 11 to rotate via the synchronous belt 12, thereby causing the moving tube 13, the guide plate 132, and the material-pulling plate 111 on it to revolve together within the temperature-regulating cavity 1001. When the whole assembly rotates, the push rods 131 and their balls 1311 at both ends of the moving tube 13 periodically contact the pressing inclined surfaces 141 fixed on the abutment blocks 14 at both ends of the cavity. Under the action of the inclined surfaces, the rotational motion is forcibly converted into continuous axial reciprocating motion of the moving tube 13 along the rotating shaft 11. When the moving tube 13 reciprocates axially, it pushes or pulls the material-pulling plate 111 through the hinge plate 15, causing it to swing back and forth around the pin within a certain angle range, which can generate strong, constantly changing turbulence within the temperature-regulating cavity 1001. This wide-range, dead-zone-free agitation ensures highly uniform temperature of the heat-conducting liquid within the cavity, preventing localized overheating or undercooling and effectively preventing fouling, maintaining the long-term cleanliness and efficiency of the heat exchange surface. Simultaneously, the inclined guide plate 132 rotates and reciprocates with the moving tube 13, directionally guiding the heat-conducting liquid from the center of the temperature-regulating cavity 1001 to the inner wall of the sleeve 10 and the outer wall of the moving tube 203, thereby destroying the laminar boundary layer on its surface. This enhances the convective heat transfer efficiency between the heat-conducting liquid and the metal wall, ensuring that the reaction heat energy is extracted most efficiently and quickly. Compared to independent control of multiple motors, the mechanical linkage structure reduces the complexity of the electrical control system, lowers the failure rate, and improves the long-term operational stability of the equipment.

[0083] This invention also discloses a method for preparing low Mooney tetrafluoropropylene rubber based on a tubular reactor, which is carried out using the aforementioned apparatus for preparing low Mooney tetrafluoropropylene rubber based on a tubular reactor, and includes the following steps:

[0084] S1: Heat-conducting liquid at a predetermined temperature is introduced into the temperature-regulating chamber 1001 through the liquid inlet 402 and flows out from the liquid outlet 502 to form a circulation;

[0085] Start the drive motor 6 and run it under no-load for a while to confirm that the stirring mechanism in the movable tube 203, rotating rod 3, spiral blade 8 and temperature regulating chamber 1001 is running smoothly and without jamming.

[0086] S2: The prepared reaction materials are continuously fed into the device through the feed inlet 401 by the metering pump, while the drive motor 6 is kept running.

[0087] S3: The material moves forward in the movable tube 203, and the rotating rod 3 rotates under the drive of the drive motor 6;

[0088] Since the slider is embedded in the spiral track groove 9 of the rotating rod 3, when the rotating rod 3 rotates, the slider is forced to slide along the track groove, thereby driving the entire connecting piece 7 and the spiral blade 8 to make axial reciprocating motion along the guide rod 704.

[0089] The drive gear 602 on the drive rod 601 drives the movable gear 603, and the movable gear 603 then meshes with the driven gear 604 fixed on the inner wall of the movable tube 203, thereby causing the movable tube 203 to rotate slowly around its axis.

[0090] The combined motion of the spiral blade 8 reciprocating axially relative to the guide rod 704 and rotating relative to the movable tube 203 mixes the material and scrapes the inner wall to prevent material stratification.

[0091] S4: When the drive rod 601 rotates, it drives the rotating shaft 11 and the feeding plate 111 to rotate in the temperature control chamber 1001 through the synchronous belt 12 and the synchronous pulley. When the rotating shaft 11 rotates, it drives the moving tube 13 to rotate synchronously. The balls 1311 at the ends of the push rods 131 at both ends of the moving tube 13 roll on the extrusion inclined surface 141 fixed to the abutment block 14. Due to the inclined surface, the moving tube 13 will generate axial reciprocating motion while rotating. The moving tube 13 pushes the feeding plate 111 through the hinge plate 15, causing it to swing around the pin shaft, thereby adding angular swing on the basis of rotation and stirring, forming turbulence in the whole area without dead zones, ensuring that the reaction heat is carried away in time.

[0092] The guide plate 132 on the moving tube 13 moves with it, continuously guiding the heat-conducting liquid in the middle of the temperature-regulating cavity 1001 to the inner wall of the sleeve 10 and the outer wall of the moving tube 203, directly flushing the possible boundary layer and enhancing the heat transfer at the wall surface.

[0093] S5: The low Mooney tetrafluoropropylene rubber compound that has completed the reaction is continuously discharged from the discharge port 501;

[0094] By adjusting the speed of the drive motor 6, the material residence time and mixing intensity can be changed;

[0095] The reaction temperature is precisely controlled by adjusting the temperature and flow rate of the heat-conducting liquid;

[0096] S6: Finally, stop feeding, wait for the material in the pipe to be emptied, then introduce solvent for cleaning, and then stop the drive motor 6 and the temperature control system.

[0097] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0098] The above description is only a preferred 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 of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An apparatus for preparing low Mooney tetrafluoropropylene rubber based on a tubular reactor, comprising two supports (1) and a reaction tube (2) disposed between the two supports (1), characterized in that, The reaction tube (2) includes: The first seat (201) is fixedly connected to one of the supports (1) and has a driving structure inside it; Tail seat body (202), the tail seat body (202) is fixedly connected to another support (1), and a rotating rod (3) driven by a driving structure is rotatably provided between the tail seat body (202) and the head seat body (201). The movable tube (203) is rotatably disposed between the first seat body (201) and the tail seat body (202) for the reaction mixing of materials; The inlet and outlet structure is set at both ends of the movable tube (203) for material to enter and exit the reaction tube (2). The rotating rod (3) is provided with a scraping component for assisting material mixing; The first seat body (201) includes a main body (2011) fixedly connected to one of the supports (1), a connecting ring (2012) fixedly connected to the main body (2011), and a connecting plate (2013) fixedly connected to the connecting ring (2012). The rotating rod (3) is rotatably mounted on the connecting plate (2013), and the inner side wall of the movable tube (203) is rotatably mounted to the outer side wall of the connecting plate (2013). The drive structure includes a drive motor (6) fixed on the main board (2011), a drive rod (601) fixedly connected to the output shaft of the drive motor (6), a drive gear (602) set on the drive rod (601), a movable gear (603) rotatably set between the main board (2011) and the connecting plate (2013) via a rotating shaft, and a driven gear (604) fixed on the inner wall of the movable tube (203) and meshing with the movable gear (603). One end of the rotating rod (3) is fixedly connected to the end of the drive rod (601) away from the drive motor (6). The scraping assembly includes a connector (7) disposed on the rotating rod (3) and a spiral blade (8) connected to the end of the connector (7) away from the rotating rod (3). The edge of the spiral blade (8) is provided with a rubber scraper (801) that moves against the inner wall of the movable tube (203). The connector (7) includes a fixed rod (701) connected to the rotating rod (3), a collar (702) disposed at the end of the fixed rod (701), and a connecting rod (703) fixedly connected to the collar (702). The end of the connecting rod (703) away from the collar (702) is fixedly connected to the spiral blade (8). A guide rod (704) is fixed between the connecting plate (2013) and the tailstock body (202), and the collar (702) is slidably connected to the guide rod (704); The outer wall of the rotating rod (3) is provided with a spiral track groove (9), and a slider that is fixedly connected to the fixed rod (701) is slidably connected in the spiral track groove (9). The inner wall of the spiral track groove (9) is provided with an arc surface with the opening facing outward.

2. The plant for the preparation of low Mooney tetrapropylene fluoroelastomer based on tubular reactor according to claim 1, characterized by the fact that, The feeding and discharging structure includes a feeding assembly and a discharging assembly. The feeding assembly includes a feeding ring (4) disposed on a support (1) connected to one end of the first seat body (201) and a feeding port (401) fixed on the feeding ring (4). One end of the movable tube (203) is provided with a feeding groove (2031) that cooperates with the feeding port (401). The discharging assembly includes a discharging ring (5) disposed on a support (1) connected to one end of the tail seat body (202) and a discharging port (501) fixed on the discharging ring (5). The other end of the movable tube (203) is provided with a discharging groove (2032) that cooperates with the discharging port (501).

3. The plant for the preparation of low Mooney tetrapropylene fluoroelastomer based on tubular reactor according to claim 2, characterized by the fact that, A sleeve (10) is fixed between the feed ring (4) and the discharge ring (5). A temperature regulating cavity (1001) for the flow of heat-conducting liquid is formed between the inner wall of the sleeve (10) and the outer wall of the movable tube (203). An inlet hole (402) communicating with the temperature regulating cavity (1001) is opened on the feed ring (4), and an outlet hole (502) communicating with the temperature regulating cavity (1001) is opened on the discharge ring (5).

4. The plant for the preparation of low Mooney tetrapropylene fluoroelastomer based on tubular reactor according to claim 3, characterized by the fact that, A rotating shaft (11) is rotatably disposed inside the temperature regulating cavity (1001), and a plurality of material-pulling plates (111) are disposed on the rotating shaft (11). One end of the rotating shaft (11) passes through the feed ring (4) and the support (1) connected thereto and is connected to the first synchronous pulley. The output shaft of the drive motor (6) is connected to the second synchronous pulley. A synchronous belt (12) is provided between the first synchronous pulley and the second synchronous pulley.

5. The apparatus for preparing low Mooney tetrafluoropropylene rubber based on a tubular reactor according to claim 4, characterized in that, A movable tube (13) is slidably connected to the outside of the rotating shaft (11). Both ends of the movable tube (13) are provided with push rods (131). The ends of the push rods (131) are provided with ball bearings (1311). The temperature regulating chamber (1001) is provided with abutting blocks (14) on the outer walls of the feed ring (4) and the discharge ring (5). The two abutting blocks (14) are provided with extrusion slopes (141) with parallel inclined surfaces. The movable tube (13) is provided with several guide plates (132) that are inclined toward the inner wall of the sleeve (10) and the outer wall of the movable tube (203).

6. The plant for the preparation of low Mooney tetrapropylene fluoroelastomer based on tubular reactor according to claim 5, characterized by the fact that, The material feeding plate (111) is rotatably mounted on the rotating shaft (11) via a pin, and a hinge plate (15) is movably arranged between the moving tube (13) and the material feeding plate (111).

7. A process for the production of low Mooney tetrapropylene fluoro-rubber based on a tubular reactor, by applying the apparatus for the production of low Mooney tetrapropylene fluoro-rubber based on a tubular reactor according to claim 6, characterized in that, Includes the following steps: S1: Heat-conducting liquid at a predetermined temperature is introduced into the temperature-regulating chamber (1001) through the liquid inlet (402) and flows out from the liquid outlet (502) to form a circulation; Start the drive motor (6) and run it under no-load for a while to confirm that the stirring mechanism in the moving tube (203), rotating rod (3), spiral blade (8) and temperature regulating chamber (1001) runs smoothly and without jamming. S2: The prepared reaction materials are continuously fed into the device from the feed port (401) through the metering pump, while the drive motor (6) is kept running. S3: The material moves forward in the active tube (203), and the rotating rod (3) rotates under the drive of the drive motor (6); Since the slider is embedded in the spiral track groove (9) of the rotating rod (3), when the rotating rod (3) rotates, the slider is forced to slide along the track groove, thereby driving the entire connecting piece (7) and the spiral blade (8) to make axial reciprocating motion along the guide rod (704); The drive gear (602) on the drive rod (601) drives the movable gear (603), and the movable gear (603) then meshes with the driven gear (604) fixed on the inner wall of the movable tube (203), thereby causing the movable tube (203) to rotate slowly around its axis. The combined motion of the spiral blade (8) reciprocating axially relative to the guide rod (704) and rotating relative to the movable tube (203) mixes the material and scrapes the inner wall to prevent material stratification; S4: When the drive rod (601) rotates, it drives the rotating shaft (11) and the feeding plate (111) to rotate in the temperature control chamber (1001) through the synchronous belt (12) and the synchronous wheel. When the rotating shaft (11) rotates, it drives the moving tube (13) to rotate synchronously. The ball (1311) at the end of the push rod (131) at both ends of the moving tube (13) rolls on the extrusion inclined surface (141) fixed to the abutment block (14). Due to the effect of the inclined surface, the moving tube (13) will generate axial reciprocating motion while rotating. The moving tube (13) pushes the feeding plate (111) through the hinge plate (15) to make it swing around the pin shaft, thereby adding angular swing on the basis of rotation and stirring, forming turbulence in the whole area without dead zone, ensuring that the reaction heat is carried away in time. The guide plate (132) on the moving tube (13) moves with it, continuously guiding the heat-conducting liquid in the middle of the temperature-regulating cavity (1001) to the inner wall of the sleeve (10) and the outer wall of the moving tube (203), directly flushing the boundary layer that may be formed, and enhancing the heat transfer at the wall surface; S5: The low Mooney tetrafluoropropylene rubber compound that has completed the reaction is continuously discharged from the outlet (501); By adjusting the speed of the drive motor (6), the material residence time and mixing intensity can be changed; The reaction temperature is precisely controlled by adjusting the temperature and flow rate of the heat-conducting liquid; S6: Finally, stop feeding, wait for the material in the pipe to be emptied, then introduce solvent for cleaning, and then stop the drive motor (6) and temperature control system.

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