Device and method for preparing catalyst carrier for polyimide synthesis by oxidation

Abstract

The present invention relates to the technical field of reactors for chemical preparation, and specifically to an oxidation preparation device and method for a catalyst carrier for polyimide synthesis. Graphite material or potassium permanganate is fed into a feed port, and the feed sequentially falls along a feed pipe, a feed channel, and a vertical drop channel, and is pushed along a horizontal drop channel. Simultaneously, the main shaft is controlled to rotate axially to drive a stirring blade for mixing and stirring. Simultaneously, an annular table drives an axial rotation of a spreading roller, so that the pushed material in the horizontal drop channel sequentially falls into a strip groove. When the strip groove turns away from a side connecting blade on one side, the feed is spread into a kettle. When the strip groove turns into the bottom end of the side connecting blade on the other side, a scraper elastically extends downward and abuts against the outer side of the spreading roller, so as to prevent the liquid in the kettle from entering the horizontal drop channel along the spreading roller, thereby facilitating more efficient mixing and uniform oxidation reaction, and reducing the difficulty of controlling temperature and feeding rate as well as deep oxidation.

Description

Technical Field

[0001] The present invention relates to the technical field of reactors for chemical preparation, and in particular to an oxidation preparation device and method for a catalyst carrier for polyimide synthesis. Background Art

[0002] The polyimide monomer 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) is a white crystalline powder mainly used to produce polyimide. Its preparation method generally adopts the condensation reaction of chlorophthalic anhydride, alkali solution, auxiliary agent and catalyst. Among them, the catalyst is often a metal-supported graphene that can be repeatedly applied. One of the key factors determining its application quality is the catalyst support material, such as the graphene support material. For the preparation of graphene support materials, such as the nitrogen-doped graphene, Pd-loaded nitrogen-doped graphene catalyst and its preparation method and application disclosed in Chinese patent document CN104998631A, it is generally prepared through oxidation reaction, drying, roasting, screening and other steps. Among them, for the initial oxidation preparation process, the Hummers method and its improved method are generally used, which specifically includes slowly adding graphite to concentrated sulfuric acid or mixed acid solution under cold bath conditions for low-temperature pre-oxidation, and then slowly adding potassium permanganate ( KMnO4) and other strong oxidants to avoid violent heat release, then heat up and continue stirring to carry out a sufficient deep oxidation reaction, and finally add deionized water, hydrogen peroxide, etc. to terminate the reaction to obtain a graphene oxide dispersion. In actual preparation, especially when using large-scale reactors for oxidation preparation production, whether adding graphite raw materials or strong oxidants such as potassium permanganate, the temperature and feeding rate must be strictly controlled. It is often necessary to design a powder conveying and dispersion system, and cooperate with multiple feeding ports or feeding nozzles to feed toward the liquid surface in the reactor. In addition, multi-point temperature monitoring is arranged in the reactor, and the feeding rate is adjusted in real time according to temperature changes to avoid local overheating, which may cause side reactions (such as excessive oxidation of graphite, structural damage) or even splashing or explosion risks. It is also necessary to arrange multi-point bypass sampling mechanisms in the reactor to analyze the oxidation degree of graphite in real time to avoid uneven distribution of oxidants caused by insufficient stirring efficiency, which in turn affects the quality of the oxidation consistency of the graphite layer. Therefore, further optimization and improvement are needed. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to propose an oxidation preparation device and method for a catalyst carrier for polyimide synthesis, so as to solve the problems of existing catalyst carriers, especially when large-scale reactors are used for oxidation preparation, such as difficulty in controlling the temperature and feeding rate in the reactor, difficulty in controlling the depth of oxidation, and inconvenience in process operation.

[0004] Based on the above purpose, the present invention provides an oxidation preparation device for a catalyst carrier for polyimide synthesis, comprising a reactor provided with a stirring mechanism:

[0005] The stirring mechanism includes a main shaft, the side end of the main shaft is horizontally connected to the stirring blade, a shaft sleeve is fixed at the top of the reactor, the shaft sleeve is sleeved on the outside of the main shaft, the side end of the shaft sleeve is externally connected to the feed pipe, a vertical drop channel is opened in the main shaft, and a horizontal drop channel is opened at the bottom end of the stirring blade. The feed falls along the feed pipe and the vertical drop channel in sequence, and is pushed along the horizontal drop channel.

[0006] A spreading roller is provided at the outer bottom end of the stirring blade along its length direction, and a plurality of strip grooves are arranged at intervals on the outer periphery of the spreading roller. The length direction of the strip grooves is parallel to the length direction of the spreading roller. Side connecting leaves are fixedly connected to both sides of the bottom end of the stirring blade. The bottom ends of the side connecting leaves are attached to the spreading roller, and a scraper is provided in at least one side of the side connecting leaf;

[0007] An annular table is set up along the circumference of the reactor, and the annular table is connected to the end of the spreading roller away from the main shaft. When the main shaft rotates axially, the spreading roller is driven to rotate axially through the annular table, so that the push materials in the horizontal blanking channel fall into the strip grooves in sequence. When the strip grooves turn away from the side connecting leaves on one side, the feed is spread into the reactor, and the scraper in the side connecting leaves on the other side elastically extends downward and abuts against the outer side of the spreading roller.

[0008] Preferably, a spiral coil is provided in the reactor, and both ends of the spiral coil are connected to liquid receiving pipes, which vertically pass through the reactor.

[0009] Preferably, a baffle is fixedly connected to the inner side of the spiral coil, and a plurality of baffles are spaced apart along the inner circumference of the spiral coil, and the annular platform is fixedly connected to the inner side of the baffle.

[0010] Preferably, a plurality of stirring blades are spaced apart along the periphery of the main shaft, and multiple layers are spaced apart up and down along the main shaft.

[0011] Preferably, an end plate is provided at the end of the spreading roller, which is fixedly connected to the bottom end of the side connecting leaf. The end of the spreading roller is fixedly connected to a roller shaft, one end of the roller shaft passes through the end plate and is connected to a gear, and a tooth structure is provided on the annular platform that is meshed with the gear.

[0012] Preferably, the roller shaft at one end passes through the main shaft and is connected to a cam. A thin shaft is provided parallel to the vertical blanking channel, and the bottom end of the thin shaft passes through the vertical blanking channel. A sealing bellows is connected between the bottom end of the thin shaft located in the vertical blanking channel and the vertical blanking channel. When the spreading roller rotates axially, the cam is driven to rotate synchronously to push the thin shaft to vibrate up and down.

[0013] Preferably, a breaker hammer is connected to the top of the thin shaft located in the vertical blanking channel.

[0014] Preferably, the scrapers are symmetrically arranged in the side connecting leaves on both sides, the bottom end of the horizontal material drop channel is rotatably connected to the walking wheel, the bottom end of the walking wheel is attached to the outer end of the spreading roller for walking, one side of the walking wheel is connected to the winding wheel, and a pull rope is wound around the winding wheel. One end of the pull rope is inserted into the side connecting leaf and connected to the scraper. When the spreading roller rotates axially, it drives the walking wheel to rotate synchronously, so that the pull rope on one side is tensioned, and the tensioned pull rope pulls the scraper, so that the scraper on the same side cannot be elastically extended.

[0015] The present invention also provides a method for preparing a catalyst support for polyimide synthesis by oxidation, comprising the following steps:

[0016] During oxidation preparation, concentrated sulfuric acid or mixed acid solution is added into the reactor through the feeding port, and then graphite material is added through the feeding port. The feed material falls along the feeding pipe, the feeding channel, and the vertical dropping channel in sequence, and is pushed along the horizontal dropping channel. At the same time, the main shaft is controlled to rotate axially to drive the stirring blade to mix and stir. When the stirring blade rotates, the spreading roller is driven to rotate axially through the annular table, so that the pushed material in the horizontal dropping channel falls into the strip groove in sequence. When the strip groove turns away from the side connecting leaf on one side, the feed material is spread into the reactor. When the strip groove turns to the bottom end of the side connecting leaf on the other side, the scraper elastically extends downward and abuts against the outer side of the spreading roller to prevent the acid liquid in the reactor from entering the horizontal dropping channel along the spreading roller.

[0017] After low-temperature pre-oxidation, strong oxidants such as potassium permanganate are slowly added in batches from the feed port, and the potassium permanganate powder is then sprinkled into the kettle as the strip grooves rotate;

[0018] After the spreading is completed, the temperature in the kettle is controlled to rise and stirring is continued to carry out a sufficient deep oxidation reaction. Deionized water, hydrogen peroxide and other liquid materials are then introduced from the feed port to terminate the reaction. The excess potassium permanganate is removed to obtain a graphene oxide dispersion. The dispersion is discharged from the drain port at the bottom of the reactor and then subjected to subsequent washing, drying, roasting, screening and other processes to obtain a graphene carrier material.

[0019] The beneficial effects of the present invention are as follows: concentrated sulfuric acid or mixed acid liquid is added into the reactor through the feeding port, and then graphite material is added through the feeding port. The feed material falls in turn along the feeding pipe, the feeding channel, and the vertical dropping channel, and is pushed along the horizontal dropping channel. At the same time, the main shaft is controlled to rotate axially to drive the stirring blade to mix and stir. When the stirring blade rotates, the axial rotation of the spreading roller is driven by the annular table to make the pushed material in the horizontal dropping channel fall into the strip groove in turn. When the strip groove turns away from the side connecting leaf on one side, the feed material is spread into the reactor. When the strip groove turns to the bottom end of the side connecting leaf on the other side, the scraper elastically extends downward and abuts against the outer side of the spreading roller to prevent the acid liquid in the reactor from entering the horizontal dropping channel along the spreading roller, and the low temperature After pre-oxidation, strong oxidants such as potassium permanganate are slowly added in batches from the feed port, and potassium permanganate powder is then sprinkled into the kettle as the strip grooves rotate. After the sprinkling is completed, the temperature in the kettle is controlled to rise and stirring is continued to carry out a sufficient deep oxidation reaction. Liquid materials such as deionized water and hydrogen peroxide are then introduced from the feed port to terminate the reaction to obtain a graphene oxide dispersion. The dispersion is discharged from the discharge port at the bottom of the reactor and then subjected to subsequent washing, drying, roasting, screening and other processes to obtain a graphene carrier material. Among them, powders such as graphite or potassium permanganate are sprinkled below the liquid surface in the kettle as the stirring blades rotate, which is conducive to more efficient mixing and uniform oxidation reaction, and reduces the difficulty of controlling temperature and feeding rate as well as deep oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 Schematic diagram of the overall internal structure of the reactor of the present invention;

[0022] Figure 2 For the present invention Figure 1 A magnified schematic diagram of point A in the middle;

[0023] Figure 3 For the present invention Figure 1 A magnified schematic diagram of point B in the middle;

[0024] Figure 4 Schematic diagram of the top view of the spiral coil and baffle of the present invention;

[0025] Figure 5 Schematic diagram of the side view of the stirring blade of the present invention;

[0026] Figure 6 It is a side view structural diagram of the horizontal material drop channel and the material spreading roller of the present invention;

[0027] Figure 7 It is a side view structural schematic diagram of the spreading roller of the present invention when it rotates counterclockwise;

[0028] Figure 8 This is a schematic diagram of the structure of the stirring blade of the present invention when it is designed as a slanted blade paddle structure;

[0029] Figure 9 It is a structural schematic diagram of the traveling wheel and the pull rope of the present invention;

[0030] Figure 10 This is a schematic diagram of the overall internal structure of the reactor with a cam and a thin shaft in the present invention;

[0031] Figure 11 For the present invention Figure 10 Enlarged schematic diagram of point C in the middle.

[0032] The following are marked in the figure:

[0033] 1. Reactor; 100. Feeding port; 101. Liquid discharge port; 2. Jacket; 3. Main shaft; 31. Vertical drop channel; 4. Stirring blade; 41. Horizontal drop channel; 5. Bushing; 51. Feed channel; 6. Feed pipe; 61. Feeding port; 7. Spreading roller; 71. Strip groove; 72. Roller; 8. Side connecting blade; 9. Scraper; 10. Ring table; 11. Spiral coil; 12. Liquid receiving pipe; 13. Baffle; 14. Connecting plate; 15. End plate; 16. Gear; 17. Cam; 18. Thin shaft; 19. Sealing bellows; 20. Travel wheel; 21. Pull rope. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0035] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0036] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 As shown, an oxidation preparation device for a catalyst carrier for polyimide synthesis includes a reactor 1, a stirring mechanism is provided in the reactor 1, the stirring mechanism includes a main shaft 3, the side end of the main shaft 3 is horizontally connected to a stirring blade 4, a shaft sleeve 5 is fixedly provided at the top end of the reactor 1, the shaft sleeve 5 is sleeved on the outside of the main shaft 3, the side end of the shaft sleeve 5 is externally connected to a feed pipe 6, a vertical drop channel 31 is provided in the main shaft 3, a horizontal drop channel 41 is provided at the bottom end of the stirring blade 4, the feed falls along the feed pipe 6 and the vertical drop channel 31 in sequence, and is pushed along the horizontal drop channel 41, a spreading roller 7 is provided at the outer bottom end of the stirring blade 4 along its length direction, and a plurality of strip grooves 71 are arranged at intervals on the periphery of the spreading roller 7, and the strip grooves 7 1 is parallel to the length direction of the spreading roller 7, and side connecting leaves 8 are fixedly connected on both sides of the bottom end of the stirring blade 4. The bottom ends of the side connecting leaves 8 are attached to the spreading roller 7, and a scraper 9 is provided in the side connecting leaves 8 on at least one side. An annular table 10 is set up along the circumference of the reactor 1, and the annular table 10 is transmission-connected to the end of the spreading roller 7 away from the main shaft 3. When the main shaft 3 rotates axially, the spreading roller 7 is driven to rotate axially through the annular table 10, so that the push materials in the horizontal blanking channel 41 fall into the strip groove 71 in turn. When the strip groove 71 turns away from the side connecting leaf 8 on one side, the feed is spread into the reactor, and the scraper 9 in the side connecting leaf 8 on the other side elastically extends downward and abuts against the outer side of the spreading roller 7.

[0037] The present invention is based on the existing conventional oxidation preparation process of catalyst carriers for polyimide synthesis, such as graphene carrier materials, and the structural principle of the oxidation reactor, including a reactor 1, a stirring mechanism is provided in the reactor 1, a jacket 2 is provided on the outer periphery of the side end of the reactor 1, a heat-conducting medium (such as ethylene glycol-water solution or heat-conducting oil, etc.) is circulated in the jacket 2 for heat exchange with the interior of the reactor 1, the stirring mechanism includes a main shaft 3 vertically extending into the reactor 1, the side end of the main shaft 3 is laterally connected with a stirring blade 4, specifically, the stirring mechanism also includes a power device such as a driving motor fixed to the top of the reactor 1 for driving the main shaft 3 to rotate axially, the reactor 1 is usually designed to be cylindrical, and a feeding port 100 is also provided at the top of the reactor 1, the main shaft 3 extends into the reactor 1 along the central axis direction of the reactor 1, a shaft sleeve 5 is fixed on the top of the reactor 1, the shaft sleeve 5 is sleeved on the outside of the main shaft 3, but does not affect the rotation of the main shaft 3, and the side end of the shaft sleeve 5 is fixedly connected to a feed pipe 6, such as Figure 1As shown, the feed pipe 6 can be symmetrically arranged on both sides of the shaft sleeve 5, and the feed pipe 6 is divided into an inclined section close to the shaft sleeve 5 and a vertical pipe section connected to the top of the inclined section. The vertical pipe section passes through the reactor 1 upward and is provided with a feed port 61. A feed channel 51 is provided in the shaft sleeve 5, and the feed channel 51 is equivalent to an extension design of the feed pipe 6 in the shaft sleeve 5, which is used to communicate with the feed pipe 6. A vertical blanking channel 31 is opened in the main shaft 3 along its length direction, and the top of the vertical blanking channel 31 is connected to the bottom end of the feed channel 51. A horizontal blanking channel 41 is opened in the bottom end of the stirring blade 4 along its length direction, and the bottom end of the vertical blanking channel 31 is connected to the horizontal blanking channel 41;

[0038] Among them, the outer bottom end of the stirring blade 4 is provided with a spreading roller 7 along its length direction, and the outer periphery of the spreading roller 7 is provided with a plurality of strip grooves 71 at intervals. The length direction of the strip grooves 71 is parallel to the length direction of the spreading roller 7. The bottom ends of the stirring blade 4 are fixedly connected with side connecting blades 8 on both sides. The side connecting blades 8 can be integrally formed with the stirring blade 4, such as Figure 6 As shown, the bottom end of the side connecting leaf 8 is attached to the spreading roller 7, the bottom end of the horizontal drop channel 41 is open and faces the spreading roller 7, a scraper 9 is provided in the side connecting leaf 8 on at least one side, and an annular platform 10 is set up along the circumference of the reactor 1. The annular platform 10 is transmission-connected to the end of the spreading roller 7 away from the main shaft 3, so that when in use, that is, when the graphene carrier is oxidized and prepared, concentrated sulfuric acid or mixed acid can be added into the reactor 1 through the feeding port 100, and then graphite material can be added through the feeding port 61, wherein the graphite material can be directly fed into the reactor 1 in powder form. The graphite powder mixed air flow can also be fed into the feed port 61 through a pneumatic conveying system. The feed falls in sequence along the feed pipe 6, the feed channel 51, and the vertical drop channel 31, and is pushed along the horizontal drop channel 41. At this time, the reactor 1 is controlled to be at a cold bath temperature condition, and the main shaft 3 is controlled to rotate axially to drive the stirring blade 4 to mix and stir. When the stirring blade 4 rotates synchronously with the main shaft 3, the spreading roller 7 is driven to rotate axially through the annular table 10, so that the pushed material in the horizontal drop channel 41 falls into the strip groove 71 in sequence. Figure 6 、 Figure 7As shown, the spreading roller 7 rotates counterclockwise, and when the strip groove 71 turns away from the side connecting leaf 8 on one side, the feed is spread into the kettle. When the strip groove 71 turns into the bottom end of the side connecting leaf 8 on the other side, the scraper 9 elastically extends downward and abuts against the outer side of the spreading roller 7, preventing the acid liquid in the kettle from entering the horizontal drop channel 41 along the spreading roller 7. After low-temperature pre-oxidation, when strong oxidants such as potassium permanganate (KMnO4) are slowly added in batches, potassium permanganate powder can also be added from the feed port 61, or mixed with the air flow by pneumatic conveying. It is fed into the feed port 61 and then spread into the kettle along with the rotation of the strip groove 71. Since the pressure of the liquid in the kettle is blocked by the scraper 9, a very high feeding airflow is not required. After the spreading is completed, the temperature in the kettle is controlled to rise and stirring is continued to perform a sufficient deep oxidation reaction. At this time, the feeding stops and the liquid in the kettle will not flow back into the horizontal feeding channel 41. Finally, deionized water, hydrogen peroxide and other liquid materials can be introduced from the feed port 61 to terminate the reaction and remove excess potassium permanganate. The liquid material is spread out through the spreading roller 7, which is conducive to flushing the residual powder in the channel. In this way, a graphene oxide dispersion is obtained, which is then discharged from the discharge port 101 at the bottom of the reactor 1, and then subjected to subsequent washing, drying, roasting, screening and other processes to obtain a graphene carrier material. Among them, powders such as graphite or potassium permanganate are sprinkled below the liquid level in the reactor as the stirring blade 4 rotates. Compared with the traditional feeding port or feeding nozzle on the top of the reactor that feeds toward the liquid level in the reactor, the material is first sprinkled out synchronously with the rotation of the stirring blade 4 and sprinkled along the length direction of the bottom end of the stirring blade 4, further improving the dispersion uniformity of the material. On the other hand, the material is sprinkled The movement of the stirring blade 4, which is located below the liquid surface and close to the stirring blade 4, is conducive to the rapid diffusion of the scattered material below the liquid surface in the kettle, thereby avoiding local overheating, or side reactions (such as excessive oxidation of graphite, structural damage) or even splashing or explosion risks caused by the addition of materials retained in the local space above the liquid surface, which is conducive to more efficient mixing and uniform oxidation reaction. The mixed air flow introduced from the feed port 61 also helps to disperse the microbubbles of the feed, which is further conducive to efficient mixing and oxidation, thereby reducing the difficulty of controlling the temperature and feeding rate and the depth of oxidation.

[0039] Among them, optionally, the oxidation preparation device of the catalyst carrier of the present invention can be designed with a single reactor 1, that is, a single reactor design, and the inner wall of the reactor adopts an inner lining that is resistant to high temperature, acid corrosion and oxidation corrosion, or it can be designed as multiple reactors 1 designed in series, that is, a multi-reactor series design, according to which the graphite material is added to concentrated sulfuric acid or mixed acid solution, low-temperature mixing and stirring and pre-oxidation are carried out; then strong oxidants such as potassium permanganate are slowly added in batches; then the temperature is raised and continuous stirring is carried out to carry out sufficient deep oxidation reaction, etc., and multiple reactors 1 are designed correspondingly, and the circulating medium in the jacket 2 is adaptively selected, such as ethylene glycol-water solution (low-temperature section) or heat transfer oil (high-temperature section), and the infusion between multiple reactors can be completed in series through the drain port 101 and the feeding port 100, so as to reduce the load of a single reactor.

[0040] The scraper 9 can adopt the existing conventional design such as the elastic telescopic tube, but the cylindrical structure in the elastic telescopic tube is replaced with a plate-shaped structure, such as Figure 6 、 Figure 7 As shown, the scraper 9 may include a hollow fixed plate fixed in the side connecting leaf 8, and a movable plate is elastically inserted in the hollow fixed plate so that the movable plate elastically extends downward. The bottom end of the movable plate is connected to a scraper bar along its length. The scraper bar is designed to be equal in length to the strip groove 71 and is used to abut against the strip groove 71 to scrape the liquid in the kettle. The scraper bar can be made of existing strong acid and high temperature resistant materials such as polytetrafluoroethylene (PTFE) or fluororubber (FKM). It relies on the elastic extension of the movable plate to prevent the scraper bar from being worn. It does not affect the use of the scraper in a short period of time. Better yet, the side connecting blades 8 and the spreading rollers 7 can be designed to be detachably connected to the stirring blades 4. When maintaining after long-term use, the top cover of the kettle can be opened, and the side connecting blades 8 and the spreading rollers 7 can be removed and replaced with new ones. During short-term maintenance, the cleaning liquid can be directly introduced from the feed port 61, and the cleaning liquid is spread out through the spreading rollers 7 to achieve convenient flushing and cleaning of residual impurities in the channel. In addition, the inclination angle of the scraper 9 can be optimized for the spreading rollers 7 and the strip grooves 71 to ensure efficient scraping and liquid blocking.

[0041] In the embodiment of the present invention, optionally, a spiral coil 11 may be provided in the reactor 1. Figure 1 、 Figure 4 As shown, the spiral coil 11 is spirally arranged in a position close to the inner wall of the reactor 1, and the two ends of the spiral coil 11 (i.e., the head end at the top and the tail end at the bottom) are respectively connected to a liquid receiving pipe 12. The liquid receiving pipe 12 vertically penetrates the reactor 1 along the inner side of the spiral coil 11, and is used to circulate a cooling medium into the spiral coil 11, thereby enhancing the local heat dissipation capacity and preventing thermal runaway caused by heat release from the oxidation reaction.

[0042] In the embodiment of the present invention, optionally, a baffle 13 is fixedly connected to the inner side of the spiral coil 11, such as Figure 1 、 Figure 4 As shown, the baffles 13 are arranged vertically and are spaced apart along the inner circumference of the spiral coil 11 to enhance the stirring effect. Part of the baffles 13 are fixedly connected to the inner side of the liquid receiving pipe 12, and part of the baffles 13 are fixedly connected to the outer side with a connecting plate 14, and are fixedly connected to the inner wall of the reactor 1 through the connecting plate 14. The annular platform 10 can be fixedly connected to the inner side of the baffle 13.

[0043] In the embodiment of the present invention, optionally, a plurality of stirring blades 4 can be arranged at intervals along the outer periphery of the main shaft 3, and multiple layers can be arranged at intervals along the upper and lower sides of the main shaft 3, that is, the stirring blade 4 can adopt an existing conventional paddle type, turbine type or other structural design, such as Figure 1 As shown, the stirring blade 4 is a double-layer straight blade paddle design, that is, the width direction of the stirring blade 4 is parallel to the axial direction of the main shaft 3, as shown in FIG. Figure 8As shown, the stirring blade 4 is of inclined blade paddle design, which also does not affect the spreading of the spreading roller 7. Therefore, multiple horizontal feeding channels 41 and vertical feeding channels 31 are also provided accordingly. The side end of the main shaft 3 is located at the top of each vertical feeding channel 31 and a through opening is opened. When the through openings rotate axially with the main shaft 3, they face the feed channel 51 in turn to feed the material.

[0044] In an embodiment of the present invention, optionally, Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 As shown, the end of the spreading roller 7 is provided with an end plate 15, and the end plate 15 is fixedly connected to the bottom end of the side connecting leaf 8. Preferably, the end plate 15 can be designed as an integral part of the side connecting leaf 8. On the one hand, the spreading roller 7 is rotatably connected to the outer bottom end of the stirring blade 4, and on the other hand, the material in the strip groove 71 is prevented from leaking along the two ends of the groove. The end of the spreading roller 7 is fixedly connected to the roller shaft 72, and one end of the roller shaft 72 passes through the end plate 15 and is connected to a gear 16. The annular table 10 is provided with a toothed structure meshing with the gear 16, that is, a design similar to an annular rack, so that when the main shaft 3 rotates axially, the gear 16 meshes and moves along the annular table 10, and the transmission gear 16 rotates axially, driving the roller shaft 72 and the spreading roller 7 to rotate axially.

[0045] The annular platform 10 can be designed as a single-layer structure, that is, the top surface of the annular platform 10 is provided with a tooth structure engaged with the gear 16. The annular platform 10 can also be designed as an upper and lower double-layer structure, such as Figure 1 、 Figure 3 As shown, for example, the upper annular platform 10 is designed as a flat plate for limiting the movement of the gear 16, and the top surface of the lower annular platform 10 is provided with a toothed structure that meshes with the gear 16. More preferably, the upper and lower annular platforms 10 can also elastically clamp the gear 16, which is conducive to more stable meshing and rotation of the gear 16.

[0046] As another optional embodiment of the present invention, Figure 10 、 Figure 11 As shown, the roller shaft 72 at one end passes through the main shaft 3 and is connected to the cam 17. A thin shaft 18 is provided parallel to the vertical blanking channel 31. The bottom end of the thin shaft 18 passes through the vertical blanking channel 31. The thin shaft 18 is located at the bottom end of the vertical blanking channel 31 and a sealing bellows 19 is connected between the vertical blanking channel 31. When the spreading roller 7 rotates axially, the cam 17 is driven to rotate synchronously, which is used to push the thin shaft 18 to vibrate up and down, and then drive the sealing bellows 19 to reciprocate up and down. The sealing bellows 19 plays a sealing role on the one hand, and on the other hand, it plays a role of reciprocating up and down to prevent blockage at the bends in the pipeline.

[0047] Specifically, a roller may be connected to the bottom end of the thin shaft 18 , and the roller abuts against the cam 17 .

[0048] More preferably, a breaker hammer may be connected to the top of the thin shaft 18 in the vertical blanking channel 31 , which vibrates up and down with the thin shaft 18 , thereby also preventing material from being blocked at the top turning point in the vertical blanking channel 31 .

[0049] As another optional embodiment of the present invention, Figure 9 As shown, the scraper 9 can also be symmetrically arranged in the side connecting leaves 8 on both sides, and the bottom end of the horizontal blanking channel 41 is rotatably connected to the walking wheel 20, wherein the length of the strip groove 71 is less than the length of the spreading roller 7, and the bottom end of the walking wheel 20 is attached to the outer end of the spreading roller 7 for walking, that is, the walking wheel 20 is located at the outer end of the strip groove 71 for walking, and one side of the walking wheel 20 is connected to a winding wheel, and a pull rope 21 is wound around the winding wheel. One end of the pull rope 21 passes through the side connecting leaf 8 and is connected to the scraper 9, so as to be shown in FIG. Figure 9 As shown, scrapers 9 can be provided in the side connecting leaves 8 on both sides. When the spreading roller 7 rotates axially, the walking wheel 20 is driven to rotate synchronously, so that the pull rope 21 on one side is tightened, and the tightened pull rope 21 pulls the scraper 9, so that the scraper 9 on the same side cannot be elastically extended. If the spreading roller 7 rotates in the opposite direction, it drives the walking wheel 20 to rotate in the opposite direction, and the pull rope 21 on the other side is tightened, so that the scraper 9 on the same side still cannot be elastically extended, that is, the function of unilateral spreading, and the unilateral scraper 9 popping out and scraping off the liquid is also realized.

[0050] The present invention also provides a method for preparing a catalyst support for polyimide synthesis by oxidation, comprising the following steps:

[0051] During oxidation preparation, concentrated sulfuric acid or mixed acid solution is fed into the reactor 1 through the feeding port 100, and then graphite material is fed into the feeding port 61. The feed material falls in sequence along the feeding pipe 6, the feeding channel 51, and the vertical dropping channel 31, and is pushed along the horizontal dropping channel 41. At the same time, the main shaft 3 is controlled to rotate axially to drive the stirring blade 4 to mix and stir. When the stirring blade 4 rotates, the spreading roller 7 is driven to rotate axially through the annular table 10, so that the pushed material in the horizontal dropping channel 41 falls into the strip groove 71 in sequence. When the strip groove 71 turns away from the side connecting leaf 8 on one side, the feed material is spread into the reactor. When the strip groove 71 turns to the bottom end of the side connecting leaf 8 on the other side, the scraper 9 elastically extends downward and abuts against the outer side of the spreading roller 7 to prevent the acid in the reactor from entering the horizontal dropping channel 41 along the spreading roller 7.

[0052] After low-temperature pre-oxidation, a strong oxidant such as potassium permanganate is slowly added in batches from the feed port 61, and the potassium permanganate powder is then scattered into the kettle along with the rotation of the strip groove 71;

[0053] After the spreading is completed, the temperature in the reactor is controlled to rise and stirring is continued to carry out a sufficient deep oxidation reaction, and then deionized water, hydrogen peroxide and other liquid materials are introduced from the feed port 61 to terminate the reaction, and the excess potassium permanganate is removed to obtain a graphene oxide dispersion. The dispersion is discharged from the drain port 101 at the bottom of the reactor 1, and then the graphene carrier material is obtained through subsequent washing, drying, roasting, screening and other processes.

[0054] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. An oxidation preparation device for a catalyst carrier for polyimide synthesis, comprising a reactor (1) provided with a stirring mechanism, characterized in that: The stirring mechanism comprises a main shaft (3), the side end of the main shaft (3) is laterally connected to a stirring blade (4), a shaft sleeve (5) is fixedly provided at the top end of the reactor (1), the shaft sleeve (5) is sleeved on the outside of the main shaft (3), the side end of the shaft sleeve (5) is externally connected to a feed pipe (6), a vertical drop channel (31) is provided in the main shaft (3), and a horizontal drop channel (41) is provided at the bottom end of the stirring blade (4), and the feed falls in sequence along the feed pipe (6) and the vertical drop channel (31), and is pushed into the horizontal drop channel (41); The outer bottom end of the stirring blade (4) is provided with a spreading roller (7) along its length direction, and the outer periphery of the spreading roller (7) is provided with a plurality of strip grooves (71) at intervals, and the length direction of the strip grooves (71) is parallel to the length direction of the spreading roller (7), and side connecting blades (8) are fixedly connected to both sides of the bottom end of the stirring blade (4), and the bottom ends of the side connecting blades (8) are attached to the spreading roller (7), and a scraper (9) is provided in at least one side of the side connecting blade (8); An annular platform (10) is provided along the circumference of the reactor (1), and the annular platform (10) is connected to the end of the spreading roller (7) away from the main shaft (3). When the main shaft (3) rotates axially, the spreading roller (7) is driven to rotate axially through the annular platform (10), so that the push materials in the horizontal drop channel (41) fall into the strip groove (71) in sequence. When the strip groove (71) turns away from the side connecting leaf (8) on one side, the feed is spread into the reactor, and the scraper (9) in the side connecting leaf (8) on the other side elastically extends downward and abuts against the outer side of the spreading roller (7); The scrapers (9) are symmetrically arranged in the side connecting leaves (8) on both sides, and the bottom end of the horizontal drop channel (41) is rotatably connected to a walking wheel (20), and the bottom end of the walking wheel (20) is arranged on the outer end of the spreading roller (7) for walking. One side of the walking wheel (20) is connected to a winding wheel, and a pull rope (21) is wound around the winding wheel. One end of the pull rope (21) is inserted into the side connecting leaf (8) and is connected to the scraper (9). When the spreading roller (7) rotates axially, it drives the walking wheel (20) to rotate synchronously, so that the pull rope (21) on one side is tensioned. The tensioned pull rope (21) pulls the scraper (9), so that the scraper (9) on the same side cannot be elastically extended.

2. The oxidation preparation device for a catalyst carrier for polyimide synthesis according to claim 1, characterized in that: A spiral coil (11) is provided in the reactor (1), and both ends of the spiral coil (11) are connected to liquid receiving pipes (12), which vertically penetrate the reactor (1).

3. The oxidation preparation device for a catalyst carrier for polyimide synthesis according to claim 2, characterized in that: A baffle (13) is fixedly connected to the inner side of the spiral coil (11), and a plurality of baffles (13) are arranged at intervals along the inner circumference of the spiral coil (11). The annular platform (10) is fixedly connected to the inner side of the baffle (13).

4. The oxidation preparation device for a catalyst carrier for polyimide synthesis according to claim 1, characterized in that: A plurality of stirring blades (4) are arranged at intervals along the outer periphery of the main shaft (3), and multiple layers are arranged at intervals up and down along the main shaft (3).

5. The oxidation preparation device for a catalyst carrier for polyimide synthesis according to claim 1, characterized in that: The end of the spreading roller (7) is provided with an end plate (15), which is fixedly connected to the bottom end of the side connecting leaf (8). The end of the spreading roller (7) is fixedly connected to a roller shaft (72), one end of the roller shaft (72) passes through the end plate (15) and is connected to a gear (16). The annular platform (10) is provided with a toothed structure meshing with the gear (16).

6. The oxidation preparation device for a catalyst carrier for polyimide synthesis according to claim 5, characterized in that: The roller shaft (72) at one end penetrates into the main shaft (3) and is connected to a cam (17). A thin shaft (18) is provided in parallel in the vertical blanking channel (31). The bottom end of the thin shaft (18) passes through the vertical blanking channel (31). A sealing bellows (19) is connected between the bottom end of the thin shaft (18) located in the vertical blanking channel (31) and the vertical blanking channel (31). When the spreading roller (7) rotates axially, the cam (17) is driven to rotate synchronously, which is used to push the thin shaft (18) to vibrate up and down.

7. The oxidation preparation device for a catalyst carrier for polyimide synthesis according to claim 6, characterized in that: The top end of the thin shaft (18) located in the vertical blanking channel (31) is connected to a breaking hammer.

8. A method for preparing a catalyst support for polyimide synthesis by oxidation, the method using the device for preparing a catalyst support for polyimide synthesis by oxidation according to any one of claims 1 to 7, characterized in that: The following steps are involved: During oxidation preparation, concentrated sulfuric acid or mixed acid solution is added into the reactor (1) through the feeding port (100), and then graphite material is added through the feeding port (61). The material falls along the feeding pipe (6), the feeding channel (51), and the vertical dropping channel (31) in sequence, and is pushed along the horizontal dropping channel (41). At the same time, the main shaft (3) is controlled to rotate axially to drive the stirring blade (4) to mix and stir. When the stirring blade (4) rotates, the material is spread through the annular table (10). The roller (7) rotates axially so that the push materials in the horizontal blanking channel (41) fall into the strip groove (71) in sequence. When the strip groove (71) turns away from the side connecting leaf (8) on one side, the feed material is scattered into the kettle. When the strip groove (71) turns into the bottom end of the side connecting leaf (8) on the other side, the scraper (9) elastically extends downward and abuts against the outer side of the spreading roller (7), thereby preventing the acid liquid in the kettle from entering the horizontal blanking channel (41) along the spreading roller (7); After pre-oxidation, potassium permanganate powder is slowly added in batches from the feed port (61), and the potassium permanganate powder is then scattered into the kettle as the strip groove (71) rotates; After the material spreading is completed, the temperature in the reactor is controlled to rise and the stirring is continued to carry out the oxidation reaction to obtain a graphene oxide dispersion. The dispersion is discharged from the discharge port (101) at the bottom of the reactor (1) and then the graphene carrier material is obtained through subsequent washing, drying, roasting and screening processes.

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