Liquid crystal polymer solid phase polycondensation reaction device

Abstract

The utility model relates to a liquid crystal polymer solid phase polycondensation reaction device and belongs to the technical field of industrial production devices. The reaction device comprises an electric heating solid phase polycondensation reactor, the electric heating solid phase polycondensation reactor comprises a horizontal cylinder and a stirrer, the stirrer is arranged along the axis of the cylinder, the cylinder comprises an inner cylinder and an outer cylinder which are coaxially arranged in a sleeved mode, and a heat preservation area and a heating area are sequentially arranged between the inner cylinder and the outer cylinder from outside to inside. An air supply chamber is arranged at the bottom of the inner side of the outer barrel, and a plurality of air supply holes communicated with the air supply chamber are formed in the barrel wall of the bottom of the inner barrel. According to the liquid crystal polymer solid phase polycondensation reaction device, a heating device and a reaction device are integrated, so that the timeliness of reaction temperature control is ensured, and energy conservation and consumption reduction are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial production equipment, in particular to a liquid crystal polymer solid phase polycondensation reaction device. Background Art

[0002] Liquid crystal polymers (LCPs) are a new type of material developed in the 1960s. They possess excellent heat resistance, dielectric properties, mechanical properties, creep resistance, radiation resistance, and chemical stability, as well as superior mechanical properties and processability. They are widely used in aviation, aerospace, transportation, chemical equipment, and the electronics industry. Liquid crystal polymers can be categorized as thermotropic and lyotropic, with thermotropic types being more widely used. Thermotropic liquid crystal polymers have high melting points and high melt viscosities. Their synthesis typically begins with melt polymerization of a low-molecular-weight prepolymer. This is then followed by solid-state polycondensation and viscosity enhancement through esterification or transesterification reactions in equipment such as rotary drums or fluidized beds at temperatures 20-40°C below the melting point, under vacuum or inert gas, to produce a high-molecular-weight product. Polymer particles enter from the top of the fluidized bed reactor and slowly fall into the bed. High-temperature inert gas enters from the bottom of the fluidized bed reactor and moves upward in countercurrent to form fluidizing wind, which drives the polymer particles to fluidize while transferring heat and mass. The small molecular by-products produced by the condensation reaction are transferred from the polymer particles to the fluidizing gas and are carried out of the reactor.

[0003] When using a fluidized bed for solid-phase polycondensation and viscosity increase, a high fluidizing gas velocity and a large fluidizing space are required to fluidize the polymer particles. This results in a large space requirement for the fluidized bed equipment and high production costs. Furthermore, a large amount of fluidizing gas increases the operating load of the subsequent tail gas treatment section, further increasing the investment in the equipment. Furthermore, the large equipment volume also increases heat loss and energy consumption. After being heated in a heat exchanger, the fluidizing gas enters the fluidized bed. Heat exchanger equipment is large and requires high investment. Higher fluidizing wind speeds increase the load on the fan and consume more energy. Furthermore, the fluidized bed polymerization process has a large overall equipment volume, requiring a large amount of insulation during construction. Furthermore, the polymer particles tumble up and down in the reactor, and the particles constantly collide and rub against each other, the inner wall of the reactor, and the fluidizing gas, leading to significant solids loss and reduced yield of qualified products. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, this utility model patent designs a liquid crystal polymer solid phase polycondensation reaction device to solve the problems of high energy consumption and large investment in the existing liquid crystal polymer solid phase polycondensation reaction in a fluidized bed.

[0005] The technical solution adopted by the utility model patent is as follows: the reaction device includes an electric heating solid-phase polycondensation reactor, the electric heating solid-phase polycondensation reactor includes a horizontal cylinder and a stirrer, the stirrer is arranged along the axis of the cylinder, the cylinder includes an inner cylinder and an outer cylinder that are coaxially sleeved, the inner cylinder and the outer cylinder are between a heating zone, an air supply chamber is provided at the inner bottom of the outer cylinder, the inner cylinder is provided with a plurality of fluidizing gas holes on the bottom cylinder wall that are connected to the air supply chamber, a plurality of air inlet pipes are connected to the bottom cylinder wall of the outer cylinder, the front end top of the inner cylinder is connected to a feed pipe, the rear end top is connected to an air outlet pipe, the feed pipe and the air outlet pipe respectively pass through the outer cylinder outward, and the bottom of the rear end face of the inner cylinder is connected to a discharge pipe.

[0006] Furthermore, the agitator includes a stirring shaft, and a number of stirring blades are evenly distributed and staggered along the axial direction on the outer periphery of the stirring shaft. The two ends of the stirring shaft are rotatably connected to the end covers at both ends of the cylinder through bearings, and the front end of the stirring shaft passes through the front end of the cylinder to connect to the variable frequency motor.

[0007] Furthermore, the interior of the stirring shaft is hollow, and temperature sensors are respectively provided at one-third and two-thirds of the axial length of the internal cavity of the stirring shaft.

[0008] Furthermore, a heat-insulating layer is integrally provided between the inner side of the outer cylinder and the heating zone, and the air supply chamber is located between the heat-insulating layer and the inner cylinder.

[0009] Furthermore, the air supply chamber is arranged along the axial direction of the bottom of the cylinder, and the multiple air inlet pipes are also evenly distributed along the axial direction.

[0010] Furthermore, support legs are connected to both sides of the bottom surface of the outer cylinder, and a reinforcing pad is provided at the connection between the support legs and the outer cylinder.

[0011] Furthermore, the air inlet pipe is connected to a heating air supply device, and the air outlet pipe is connected to an exhaust gas purification device.

[0012] Furthermore, the air outlet of the exhaust gas purification device is connected to the air inlet of the heating and air supply device to form an exhaust gas recycling system.

[0013] Furthermore, the exhaust gas recycling system includes a cyclone dust collector, a filter, a circulating fan and a heating unit connected in sequence by pipelines. The air inlet end of the cyclone dust collector is connected to the air outlet pipe of the electric heating solid phase condensation reactor, and the air outlet end of the heating unit is connected to the air inlet pipe of the electric heating solid phase condensation reactor.

[0014] Furthermore, a circulating gas discharge valve is provided on the air outlet pipeline of the circulating fan to connect to the exhaust gas emission treatment device, and a pressure transmitter is provided on the air inlet pipeline; a system circulating gas supply valve is provided on the air inlet pipeline of the heating unit to connect to the gas source, and a temperature transmitter is provided on the air outlet pipeline; the feed pipe of the electric heating solid phase condensation reactor is provided with a reactor feed valve to connect to the feeding pipeline, and the discharge pipe is connected to the reactor discharge valve.

[0015] Compared with the existing technology, the advancement of the liquid crystal polymer solid phase polycondensation reaction device designed by this utility model is that

[0016] The solid-phase polycondensation reactor is divided into two compartments: an inner cylinder and an outer cylinder. An electric heater is installed between the inner and outer cylinders, and the inner cylinder forms the material reaction zone, integrating the heating and reaction devices. This integrated design is energy-efficient and reduces on-site insulation work. Furthermore, the integrated design minimizes temperature control lag time and ensures more accurate temperature control.

[0017] By dividing the inner and outer cylinders and optimizing the structure, the volume of the reactor is greatly reduced, which reduces equipment investment and floor space, thereby reducing heat loss in the device and improving the economic benefits of the system.

[0018] After the liquid crystal polymer particles fall into the inner drum, they are continuously stirred by the agitator, ensuring uniform heating of the material. To ensure more even distribution of the material within the reactor, the agitator is driven by a variable frequency motor, periodically rotating forward and reverse to achieve uniform heating. A gap exists between the agitator blades and the inner drum wall. To prevent the material at the bottom of the drum from being adequately stirred, a fluidizing plenum is installed at the bottom of the drum. Heated shielding gas first enters the fluidizing plenum and then is blown into the reactor through fluidizing ports, fluidizing the small amount of material at the bottom and preventing accumulation. Since only the material at the bottom of the reactor needs to be partially fluidized, the required fluidizing air volume is significantly reduced, eliminating the need for high fluidizing gas velocities, reducing gas usage, energy consumption, and fan load. This also reduces collisions and friction between the materials, minimizing material loss.

[0019] The core of the stirring shaft is provided with a cavity, and two temperature sensors are arranged along the cavity, so that the temperature sensors enter the interior of the reactor and can directly detect the heating temperature inside the reactor, making the control and adjustment of the heating temperature of the reactor more timely and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the front cross-sectional structure of a liquid crystal polymer solid phase polycondensation reaction device.

[0021] Figure 2It is a schematic diagram of the side cross-sectional structure of a liquid crystal polymer solid phase polycondensation reaction device.

[0022] Figure 3 It is a schematic diagram of the application structure of a liquid crystal polymer solid phase polycondensation reaction device.

[0023] Description of Reference Numerals

[0024] In the figure, 1 is an electric heating solid phase polycondensation reactor, 2 is an agitator, 3 is a supporting foot, 4 is a temperature sensor, 5 is a cyclone dust collector, 6 is a filter, 7 is a circulating fan, 8 is a heating unit, 11 is an outer cylinder, 12 is an inner cylinder, 13 is an insulation layer, 14 is a heating zone, 15 is an air supply chamber, 16 is a sealed bearing, 111 is an air inlet pipe, 121 is a feed pipe, 122 is an air outlet pipe, 123 is a discharge pipe, 124 is a fluidizing air hole, 21 is a stirring shaft, 22 is a stirring blade, and 23 is a frequency conversion motor. DETAILED DESCRIPTION

[0025] The present invention is further described below with reference to the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the present invention are clearly and completely described. The embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0026] like Figure 1 、 2 As shown, this utility model patent designs an embodiment of a liquid crystal polymer solid-phase polycondensation reaction device. In this embodiment, the reaction device includes an electric heating solid-phase polycondensation reactor 1, which includes a horizontal cylinder and a stirrer 2. The stirrer 2 is arranged along the axis of the cylinder.

[0027] The cylinder comprises a coaxially sleeved inner cylinder 12 and outer cylinder 11. Between the inner cylinder 12 and the outer cylinder 11, from the inside out, are an electrically heated heating zone 14 and an insulation layer 13. An air supply chamber 15 is integrally disposed axially within a 50 cm wide range, clinging to the bottom of the inner cylinder 12. The insulation layer 13 covers the outside of the air supply chamber 15. The inner cylinder 11 has a number of fluidizing air holes 124 evenly distributed axially on its bottom wall, communicating with the air supply chamber 15. Multiple air inlet pipes 111 are evenly distributed axially on the bottom wall of the outer cylinder 11, connecting to the internal air supply chamber 15. The outer ends of the air inlet pipes 111 are connected to a heating and air supply device. The front end top of the inner cylinder 12 is connected to the feed pipe 121, and the rear end top is connected to the air outlet pipe 122. The feed pipe 121 and the air outlet pipe 122 respectively pass through the outer cylinder 11 outwards and are used to connect the feeding device and the exhaust gas treatment device. A discharge port is opened at the bottom of the rear end face of the inner cylinder 12, and is connected to the discharge pipe 123. In addition, support legs 3 are assembled or welded on both sides of the bottom surface of the outer cylinder 11 by bolts, and a layer of reinforcing pads is provided at the connection between the top of the support legs 3 and the outer cylinder 11. A reactor feed valve is provided at the feed pipe 111 of the electric heating solid phase polycondensation reactor 1 to connect the feeding pipeline, and the discharge pipe 123 is connected to the reactor discharge valve to facilitate the control of unloading.

[0028] The agitator 2 includes an agitator shaft 21, the outer periphery of which is evenly and staggered along the axial direction with a plurality of agitator blades 22 connected thereto. The two ends of the agitator shaft 21 are rotatably connected to the end caps at both ends of the barrel of the electrically heated solid-phase polycondensation reactor 1 via sealed bearings 16. The front end of the agitator shaft 21 extends from the front end of the barrel and is connected to the power output end of the variable frequency motor 23. The variable frequency motor 23 is fixedly connected to the front end cap of the barrel via a bracket. The variable frequency motor 23 can adjust the speed and can rotate in both forward and reverse directions. A cavity is provided inside the agitator shaft 21 along the axis. Temperature sensors 4 are provided in the cavity of the agitator shaft 21 at one-third and two-thirds of the axial length, respectively. The temperature sensor 4 protrudes outward from the agitator shaft 21. The temperature sensor 4 uses an existing wireless temperature transmitter and rotates synchronously with the agitator shaft 21.

[0029] Combine Figure 3As shown, when the electric heating solid phase polycondensation reactor 1 of the liquid crystal polymer solid phase polycondensation reaction device is used, since the fluidizing air used is an inert gas such as nitrogen as a protective gas, which is relatively expensive, the outlet end of the exhaust gas treatment device connected to the outlet pipe 122 is connected to the inlet end of the heating air supply device connected to the inlet pipe 111, forming an exhaust gas recycling system, including a cyclone dust collector 5, a filter 6, a circulating fan 7 and a heating unit 8 connected in sequence by pipelines. The inlet end of the cyclone dust collector 5 is connected to the outlet pipe 122 of the electric heating solid phase polycondensation reactor 1, and the outlet end of the heating unit 8 is connected to the inlet pipe 111 of the electric heating solid phase polycondensation reactor 1. In addition, a circulating gas discharge valve PV-208 is provided on the outlet end pipeline of the circulating fan 7 to connect to the exhaust gas discharge treatment device, which can discharge the exhaust gas. The inlet end pipeline of the heating unit 8 is provided with a system circulating gas supply valve PV-209 to connect to the protective gas source, which can supply gas to the reaction device. In order to better monitor the operation process of the reaction device, a pressure transmitter PT-203 is installed on the air inlet pipe of the circulation fan 7 to monitor the air inlet pressure of the circulation fan in real time, and the protective gas pressure in the circulation system is controlled by interlocking the circulation gas discharge valve PV-208 and the circulation gas supply valve PV-209; a temperature transmitter TT-204 is installed on the air outlet pipe of the heating unit 8 to monitor the air inlet temperature of the reaction device in real time.

[0030] The specific process steps for producing the liquid crystal polymer solid phase polycondensation reaction device disclosed in this utility model patent are as follows:

[0031] (1) Liquid crystal polymer feeding: First, the protective gas is turned on. The heated air supply device enters the air supply chamber 15 through the air inlet pipe 111, and then enters the inner side of the inner cylinder 12 through the fluidizing air hole 124, where the air inside is discharged, completing the gas replacement. The feed valve XV-206 at the feed pipe 121 is opened, and the liquid crystal polymer particles obtained from the granulation section enter the electrically heated solid phase polycondensation reactor 1 through the feed pipe 121.

[0032] (2) Liquid crystal polymer solid phase polycondensation reaction: The variable frequency motor 23 of the electric heating and stirrer 2 is turned on. After the liquid crystal polymer particles fall into the inner cylinder, they are constantly turned under the action of the stirrer. The stirrer 2 is driven by the variable frequency motor 23 and periodically rotates forward and reverse to achieve the purpose of uniform heating of the material. There is a gap between the stirring blade 22 of the stirrer 2 and the wall of the inner cylinder 12. The material at the bottom of the inner cylinder 12 cannot be fully turned. The heated protective gas from the air supply chamber 15 fluidizes the small amount of material at the bottom to avoid material aggregation. Since only part of the material at the bottom of the reactor needs to be fluidized, the required fluidizing air volume is greatly reduced, reducing the load of the heating unit and the fan. The two temperature sensors TT-201 and TT-202 on the stirring shaft 21 measure the temperature inside the reactor in real time and upload the data to control the heating temperature inside the reactor.

[0033] (3) Closed-loop gas circulation: After the protective gas is heated by the heating unit 8, it is sent into the reactor through the air inlet pipe 111 at the bottom of the reactor's outer cylinder 11, blowing the material at the bottom of the reactor to partially fluidize it, thereby avoiding the accumulation of the material and providing part of the heat for the polycondensation reaction. The protective gas rises in the reactor and is discharged from the air outlet 122 at the top of the rear end of the reactor. It enters the cyclone dust collector 5, captures the liquid crystal polymer powder entrained by the protective gas, and then enters the filter 6 to filter out the fine solid particles. The clean gas after filtration enters the circulating fan 7, which provides the circulation power of the protective gas and sends the protective gas back to the heating unit 8 to realize the closed-loop circulation of the protective gas. The polymer powder captured by the cyclone dust collector 5 enters the discharge hopper below through the gate valve XV-205. The pressure transmitter PT-203 at the inlet of circulating fan 7 is controlled by a split-range mechanism. When the pressure is above the set value, the circulating gas supply valve PV-209 opens to zero, the circulating gas discharge valve PV-208 opens wider, and exhaust gas is discharged. When the pressure is below the set value, the circulating gas discharge valve PV-208 opens to zero, and the circulating gas supply valve PV-209 opens wider to replenish gas. During the reactor's operational preparation phase, the circulating gas supply valve PV-209 opens at a fixed value, and the circulating gas discharge valve PV-208 automatically adjusts according to the set value of the pressure transmitter PT-203 to complete the system's gas replacement.

[0034] (4) Discharge of reaction products: When the materials in the reactor reach the solid phase polycondensation reaction time, the variable frequency motor 23 of the agitator 2 rotates forward, and the discharge valve XV-207 at the discharge pipe 123 of the reactor is opened to discharge the solid phase polycondensation products from the reactor.

[0035] The above contents are merely preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. That is, any simple equivalent changes and modifications made in accordance with the claims and description of the present invention are still within the scope of the present invention.

Claims

1. A liquid crystal polymer solid phase polycondensation reaction device, characterized in that: The reaction device includes an electric heating solid-phase condensation reactor, which includes a horizontal cylinder and an agitator. The agitator is arranged along the axis of the cylinder. The cylinder includes an inner cylinder and an outer cylinder that are coaxially sleeved. The inner cylinder and the outer cylinder are provided with a heating zone. An air supply chamber is provided at the bottom inner side of the outer cylinder. The inner cylinder has a plurality of fluidizing gas holes on the bottom cylinder wall that are connected to the air supply chamber. A plurality of air inlet pipes are connected to the bottom cylinder wall of the outer cylinder. The front end top of the inner cylinder is connected to a feed pipe, and the rear end top is connected to an air outlet pipe. The feed pipe and the air outlet pipe respectively pass through the outer cylinder outward, and the bottom of the rear end face of the inner cylinder is connected to a discharge pipe.

2. The liquid crystal polymer solid phase polycondensation reaction device according to claim 1, characterized in that: The agitator includes a stirring shaft, and a plurality of stirring blades are evenly and staggeredly connected to the outer circumference of the stirring shaft along the axial direction. The two ends of the stirring shaft are rotatably connected to the end covers at both ends of the cylinder through bearings, and the front end of the stirring shaft passes through the front end of the cylinder to connect to the variable frequency motor.

3. The liquid crystal polymer solid phase polycondensation reaction device according to claim 2, characterized in that: The interior of the stirring shaft is hollow, and temperature sensors are respectively provided at one-third and two-thirds of the axial length of the interior cavity of the stirring shaft.

4. The liquid crystal polymer solid phase polycondensation reaction device according to claim 3, characterized in that: A heat-insulating layer is integrally provided between the inner side of the outer cylinder and the heating zone, and the air supply chamber is located between the heat-insulating layer and the inner cylinder.

5. The liquid crystal polymer solid phase polycondensation reaction device according to claim 4, characterized in that: The air supply chamber is arranged along the axial direction of the bottom of the cylinder, and a plurality of air inlet pipes are evenly distributed along the axial direction.

6. The liquid crystal polymer solid phase polycondensation reaction device according to claim 5, characterized in that: Support legs are connected to both sides of the bottom surface of the outer cylinder respectively, and a reinforcing pad is provided at the connection between the support legs and the outer cylinder.

7. The liquid crystal polymer solid phase polycondensation reaction device according to claim 6, characterized in that: The air inlet pipe is connected to a heating air supply device, and the air outlet pipe is connected to an exhaust gas purification device.

8. The liquid crystal polymer solid phase polycondensation reaction device according to claim 7, characterized in that: The air outlet end of the exhaust gas purification device is connected to the air inlet end of the heating and air supply device to form an exhaust gas recycling system.

9. The liquid crystal polymer solid phase polycondensation reaction device according to claim 8, characterized in that: The tail gas recycling system includes a cyclone dust collector, a filter, a circulating fan and a heating unit connected in sequence by pipelines. The air inlet end of the cyclone dust collector is connected to the air outlet pipe of the electric heating solid phase polycondensation reactor, and the air outlet end of the heating unit is connected to the air inlet pipe of the electric heating solid phase polycondensation reactor.

10. The liquid crystal polymer solid phase polycondensation reaction device according to claim 9, characterized in that: The air outlet pipeline of the circulating fan is provided with a circulating gas discharge valve connected to the exhaust gas emission treatment device, and the air inlet pipeline is provided with a pressure transmitter; the air inlet pipeline of the heating unit is provided with a system circulating gas supply valve connected to the gas source, and the air outlet pipeline is provided with a temperature transmitter; the feed pipe of the electric heating solid phase condensation reactor is provided with a reactor feed valve connected to the feeding pipeline, and the discharge pipe is connected to the reactor discharge valve.

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