Water-phase polymerization termination reactor for PAN precursor

Abstract

The invention relates to the field of PAN precursor production equipment, in particular to a PAN precursor water-phase polymerization termination reactor which comprises a barrel of a split structure and a power device installed at the upper end of the barrel, a top cover at the upper end of the barrel is provided with a feeding port and a terminator port, a discharging port is formed in the lower portion of the barrel, a hydraulic lifting device is arranged on one side of the barrel, and the hydraulic lifting device is arranged on the other side of the barrel. The lower end of the hydraulic lifting device is fixed to the lower half portion of the barrel, the upper end of the hydraulic lifting device is connected with the upper half portion of the barrel, a stirring baffle and a center stirring shaft are arranged in the barrel, and the center stirring shaft is driven by a power device, provided with a center stirring device and connected with a planetary stirring device. The central stirring device stirs materials in the axis direction of the central stirring shaft, and the planetary stirring device rotates around the axis direction of the central stirring shaft and can conduct autorotation stirring and material scraping. The termination reactor is convenient for raw material cleaning, equipment maintenance and full mixing, and prevents the raw materials from adhering to the inner wall of the cylinder body.

Description

Technical Field

[0001] The invention relates to the field of PAN precursor production equipment, and in particular to a PAN precursor precursor water phase polymerization termination reactor. Background Art

[0002] Precursor is the key initial raw material fiber for the preparation of polyacrylonitrile (PAN) carbon fiber, and PAN precursor is prepared by spinning polyacrylonitrile raw material. The spinning raw material is generated by polymerizing acrylonitrile (AN) monomer, and then PAN precursor is obtained by wet or dry-wet spinning. After pre-oxidation, carbonization and graphitization, the linear polyacrylonitrile polymer undergoes a series of chemical reactions such as oxidation, pyrolysis, cross-linking, and cyclization to form graphite carbon fiber.

[0003] After the PAN precursor is polymerized in the aqueous phase in the polymerization reactor, the polymerization reaction needs to be terminated by introducing an appropriate amount of terminator. This operation process places strict requirements on the amount of terminator added, mixing uniformity, and temperature control of the reaction process.

[0004] In order to improve the precise control of the termination process of the polymerization reaction, it is necessary to design a termination reaction equipment with a relatively simple structure, convenient operation, and easy maintenance and cleaning. The reaction device needs to achieve continuous termination reaction and storage and transportation of raw materials through a combined structure. The structural design and configuration of the equipment has also become the focus of researchers on carbon fiber production equipment. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a PAN precursor aqueous phase polymerization termination reactor, which is equipped with a hydraulic lifting device, and can separate the upper half of the cylinder by hydraulic power, which is convenient for cleaning the raw materials in the cylinder and equipment maintenance. At the same time, a central stirring device, a planetary stirring device and a stirring baffle are provided inside the cylinder to ensure the full reaction of the raw materials and the terminator and prevent the raw materials from adhering to the inner wall, thereby stabilizing the polymerization termination process.

[0006] The technical solution provided by the present invention is as follows: The invention provides a PAN precursor aqueous phase polymerization termination reactor, comprising a cylinder with a split structure and a power device installed on the upper end of the cylinder, the upper end top cover of the cylinder is provided with a feed inlet and a terminator inlet, the lower part of the cylinder is provided with a discharge port, one side of the cylinder is provided with a hydraulic lifting device, the lower end of the hydraulic lifting device is fixed to the lower half of the cylinder, and the upper end is connected to the upper half of the cylinder, a stirring baffle and a central stirring shaft are arranged in the cylinder, the central stirring shaft is driven by the power device, a central stirring device is installed on the central stirring shaft and is connected with a planetary stirring device, the central stirring device stirs materials along the axial direction of the central stirring shaft, and the planetary stirring device rotates around the axial direction of the central stirring shaft and can perform self-rotation stirring and scrape materials.

[0007] Furthermore, the planetary stirring device includes a plurality of planetary gears and a central gear plate fixedly mounted on the inner wall of the lower half of the cylinder, a planetary shaft is fixed at the bottom of the plurality of planetary gears, a spiral belt stirring head or scraper is provided on the planetary shaft, the central stirring shaft and the planetary shaft are connected by an axial positioning ring, the central stirring shaft is located at the center of the central gear plate, and the plurality of planetary gears are respectively meshed with the central gear plate.

[0008] Furthermore, U-shaped brackets are arranged around the central gear plate, and the inner side wall of the lower part of the cylinder is provided with a slot that cooperates with the U-shaped bracket.

[0009] Furthermore, there are four planetary gears, which are evenly arranged on the inner side of the central gear disk along the circumference. There are two scrapers and two screw-belt stirring heads, which are relatively arranged. The axial positioning ring includes a main shaft ring and four radially symmetrical side shaft rings connected to it. The main shaft ring is sleeved on the central stirring shaft sleeve, and the side shaft rings are sleeved on the planetary shaft.

[0010] Furthermore, the central stirring device includes a middle four-blade agitator and a middle planetary agitator located in the middle and bottom of the central stirring shaft, and the middle four-blade agitator, the bottom four-blade agitator and the planetary stirring device are staggered and do not contact each other.

[0011] Furthermore, the upper and lower parts of the cylinder are both provided with stirring baffles, the stirring baffles adopt a raised streamlined structure, the interior of the baffles is hollow, and the ratio of the raised top height to the fixed end length of the stirring baffle is in the range of 5:1 to 10:1.

[0012] Furthermore, a heat exchange medium is introduced into the hollow area inside the stirring baffle, and the thickness of the stirring baffle is 0.5-2 mm.

[0013] Furthermore, a cooling jacket is arranged outside the cylinder, a heat exchange medium is introduced into the cooling jacket, the jacket inlet is located below the cooling jacket, the jacket outlet is located above the cooling jacket, and the angle between the jacket inlet and the jacket outlet is 180°.

[0014] Furthermore, an emergency discharge port is provided in the middle of the bottom of the cylinder, and a water inlet, a vent, a helium port, a pressure gauge port, a quick outlet and a sight glass are provided on the top cover of the cylinder.

[0015] Furthermore, control valves are provided inside the discharge port and the emergency discharge port.

[0016] Beneficial Effects

[0017] 1. The termination reactor is provided with a split cylinder structure and a hydraulic lifting device, which can separate the upper and lower cylinders by hydraulic power, making it easier to clean the raw materials in the reactor and overhaul the equipment.

[0018] 2. The termination reactor is equipped with a central stirring device to ensure uniform mixing and full reaction of the precursor raw materials and the terminator, and to ensure continuous and precise control of the termination reaction process.

[0019] 3. A special combined planetary stirring device is set up to achieve full mixing of the raw materials; through the linkage of the central stirring device and the planetary stirring device, all-round mixing of the polymerization raw materials is achieved in the three-dimensional space of a single polymerization reaction unit device to ensure full mixing of the raw materials.

[0020] 4. The termination reactor is provided with a stirring baffle with a convex streamlined structure on the inner wall of the barrel to prevent the polymerization raw materials from adhering to the inner wall of the reactor during stirring and centrifugal mixing. At the same time, the stirring baffle structure ensures that there is no stirring dead angle at the connection with the inner wall of the barrel, and ensures that the raw materials form a uniform and steady flow state during the continuous stirring process, thereby achieving uniform and sufficient mixing of the raw materials.

[0021] 5. The termination reactor is equipped with a jacketed cylinder, into which circulating water can be introduced to meet different heating or cooling requirements and effectively control and adjust the temperature during the reaction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a front view of a PAN precursor aqueous phase polymerization termination reactor according to the present invention.

[0023] Figure 2 It is a schematic cross-sectional view of the upper end cover of the cylinder of a PAN precursor aqueous phase polymerization termination reactor of the present invention.

[0024] Figure 3 It is a structural schematic diagram of a planetary stirring device of a PAN precursor water phase polymerization termination reactor of the present invention.

[0025] Figure 4 It is a bottom view of a planetary stirring device of a PAN precursor water phase polymerization termination reactor of the present invention.

[0026] Description of the reference numerals: 1. Jacket elliptical head; 2. Cylinder elliptical head; 3. Cooling jacket; 4. Cylinder; 5. Stirring baffle; 6. Ear support; 7. Nameplate; 8. Power device; 9. Hydraulic lifting device; 10. Middle four-blade agitator; 11. Bottom four-blade agitator; 12. Cylindrical support leg; 13. Stirring baffle; 14. Center stirring shaft; 15. Fixing device; 16. Center gear plate; 17. Shaft core positioning ring; 18. Planetary shaft; 19. Planetary gear; 20. Ribbon stirring head; 21, scraper; N1, feed port; N2, terminator port; N3, water inlet; N4, vent port; N5, helium port; N6, pressure gauge port; N7, first jacket outlet, N9, second jacket inlet; N8, first jacket outlet; N10, second jacket inlet; N11. Emergency discharge port; N12, discharge port; M, quick discharge port; S, sight glass. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0030] Example 1

[0031] An embodiment of the present invention provides a PAN precursor aqueous phase polymerization termination reactor, comprising a cylinder 4 with a split structure and a power device 8 installed on the upper end of the cylinder 4, the upper end cover of the cylinder 4 is provided with a feed port N1 and a terminator port N2, a discharge port N12 is provided below the cylinder 4, a hydraulic lifting device 9 is provided on one side of the cylinder 4, the lower end of the hydraulic lifting device 9 is fixed to the lower half of the cylinder 4, and the upper end is connected to the upper half of the cylinder 4, a central stirring shaft 14 is provided in the cylinder 4, the central stirring shaft 14 is driven by the power device 8, a central stirring device is installed on the central stirring shaft 14 and is connected to a planetary stirring device, the central stirring device stirs the material along the axial direction of the central stirring shaft 14, the planetary stirring device rotates around the axial direction of the central stirring shaft 14 and can perform self-rotation stirring and scrape the material.

[0032] The polymerization termination reactor of this embodiment uses a hydraulic lifting device to separate the upper and lower parts of the cylinder, which is convenient for maintenance and cleaning. At the same time, combined with a central stirring device and a planetary stirring device, the stirring efficiency and material mixing uniformity are improved. The internal stirring baffle can prevent the raw materials from adhering to the inner wall of the cylinder.

[0033] Example 2

[0034] like Figure 1 The present embodiment provides a PAN precursor aqueous phase polymerization termination reactor structure including a split-type cylinder 1, a hydraulic lifting device 9, a central stirring shaft 14 and a power device 8. The power device 8 is located above the cylinder 4, and the power device 8 is connected to the central stirring shaft 14 through a coupling and drives it. The cylinder 4 is divided into two parts, the upper and lower parts. The hydraulic lifting device 9 is located on the left side of the cylinder 4, the lower end of which is fixed to the lower half of the cylinder 4, and the upper end is connected to the upper half of the cylinder 4, which plays the role of lifting the upper half of the cylinder 4, and is convenient for equipment maintenance and raw material cleaning in the two-part cylinder 4.

[0035] The cooling jacket 3 is annularly wrapped outside the cylinder 4 (both the upper and lower parts are wrapped), the first jacket inlet N8 of the upper part of the cylinder is located below the cooling jacket 3 of the upper part of the cylinder, the jacket outlet N7 of the upper part of the cylinder is located above the cooling jacket 3 of the upper part of the cylinder, the second jacket inlet N10 of the lower part of the cylinder is located below the cooling jacket 3 of the lower part of the cylinder, and the jacket outlet N9 of the lower part of the cylinder is located above the cooling jacket 3 of the upper part of the cylinder, the jacket inlet and the jacket outlet are at an angle of 180°, and the temperature in the cylinder 4 is controlled by the annular flow of water. The cylinder 4 is sealed and fixed by the cylinder elliptical head 2 and the jacket elliptical head 1.

[0036] like Figure 2As shown, the top cover of the upper end of the cylinder 4 is provided with a feed port N1, a terminator port N2, a water inlet N3, a vent port N4, a helium port N5, a pressure gauge port N6, a quick outlet port M and two sight glasses S. The feed port N1 and the quick outlet port M are spaced 90° apart, and the two sight glasses S are spaced 120-150° apart, 125° in this embodiment, and the sight glasses S are provided to better observe the stirring of the material in the polymerization unit. The upper half of the cylinder 4 is provided with an ear-type support and a nameplate, the ear-type support is provided on both sides for the movement and fixation of the termination reactor on the external rack, and the nameplate is located at the side position, and the specific position can be flexibly adjusted.

[0037] An emergency discharge port N11 and a discharge port N12 are provided below the cylinder 4. Specifically, the discharge port N12 is located at the side of the cylinder 4, and the emergency discharge port N11 is located at the center of the bottom of the cylinder 4. Control valves are provided inside the discharge port N12 and the emergency discharge port N11. The emergency discharge port N11 is provided at the bottom of the termination reactor so that the material can be discharged from the equipment simply and quickly by relying on the inertia or gravity of the material movement.

[0038] The middle and bottom of the central stirring shaft 14 are equipped with a middle four-blade stirrer 10 and a bottom four-blade stirrer 11. The central stirring shaft 14 is also connected to a planetary stirring device. The middle four-blade stirrer 10 and the bottom four-blade stirrer 11 are connected to the central stirring shaft 14 through a mechanical seal. The middle four-blade stirrer 10 and the bottom four-blade stirrer 11 are connected in a ring shape with four stirring blades spaced 90 degrees apart. The planetary stirring device and the bottom four-blade stirrer 11 and the middle four-blade stirrer 10 are arranged at a certain distance to ensure that the four-blade stirring paddle of the four-blade stirrer and the stirring paddle and scraper of the planetary stirring device do not contact each other during the stirring process.

[0039] like Figure 3-4 As shown, the planetary stirring device is a special stirring structure for the termination reactor, and its structure includes: a central gear plate 16, a shaft core positioning ring 17, two sets of planetary stirring blades and two sets of side wall scrapers.

[0040] The planetary stirring paddle comprises: a stirring paddle shaft, namely a planetary shaft 18 , a planetary gear 19 and a spiral ribbon stirring head 20 .

[0041] The side wall scraper comprises: a side wall scraper shaft, namely a planetary shaft 18 , a planetary gear 19 and a scraper 21 .

[0042] The central gear plate 16 is fixed in the slot of the inner wall of the lower half of the cylinder 4 by four sets of U-shaped brackets spaced 90 degrees apart. The central stirring shaft 14 passes through the center hole of the central gear plate 16 , and the central gear plate 16 does not rotate with the central stirring shaft 14 .

[0043] Specifically, the axis positioning ring 17 includes a main axis ring and four radially symmetrical side axis rings connected thereto. The main axis ring of the axis positioning ring 17 is fixedly sleeved on the central stirring shaft 14, and its side axis rings ensure that the stirring paddle shaft and the side wall scraper shaft are connected in a certain array manner.

[0044] The planetary gear 19 of the planetary stirring paddle forms a mechanical engagement with the central gear disk 16. When the central stirring shaft 14 is driven by the power device 8, the shaft core positioning ring 17 drives multiple groups of stirring paddle shafts and side wall scraper shafts to rotate around the central stirring shaft 14. At the same time, the gear meshing action formed by the planetary gear 19 and the central gear disk 16 realizes the self-rotation of the spiral ribbon stirring head 20 and the scraper 21.

[0045] The central gear plate 16 and the planetary gear 19 of the planetary stirring device are both detachable structures, and the diameter and number of teeth of the two can be flexibly adjusted according to the stirring speed.

[0046] The stirring paddle shaft and the spiral ribbon stirring head 20 of the planetary stirring device are both detachable structures, wherein the length of the stirring paddle shaft and the type of the spiral ribbon stirring head 20 at the shaft end can be flexibly adjusted according to the stirring design requirements.

[0047] Specifically, the bottom end of the central stirring shaft 14 is connected to the stirring paddle shafts of two sets of planetary stirring paddles and two sets of side wall scraper shafts through four sets of 90° spaced shaft core positioning rings 17, and the planetary gear 19 at the upper end of the stirring paddle forms a mechanical meshing action with the central gear disk 16 fixed in the groove of the inner wall of the lower half of the cylinder 4 through four sets of U-shaped brackets spaced 90° apart to form self-rotation, and at the same time, the two sets of planetary stirring paddles and the two sets of side wall scrapers form revolution around the central stirring shaft 14.

[0048] The upper and lower parts of the cylinder 4 are both provided with stirring baffles 13, the surface of the stirring baffle adopts a convex streamlined structure, the interior of the baffle is hollow, and the ratio of the top height of the convexity to the width of the baffle at the fixed end of the inner cylinder is controlled in the range of 5:1 to 10:1.

[0049] The hollow inside of the stirring baffle 13 can be filled with cooling water or liquid nitrogen or other cooling media, and the thickness of the baffle body is controlled within the range of 0.5-2 mm.

[0050] Specifically, a plurality of stirring baffles 13 at the upper and lower parts of the cylinder 4 can be provided in an up-and-down arrangement and do not conflict with the planetary stirring device.

[0051] The number of the cylindrical legs 14 is 4 to 6, which are arranged symmetrically to provide support for the termination reactor.

[0052] The power device 8 and the cylinder 4, the upper and lower parts of the cylinder 4, the hydraulic lifting device 9 and the cylinder 4 are all connected by a fixing device, which is connected and positioned at a 180° angle to form a circular array arrangement. The fixing device is connected by a flange, and the flange is combined and connected and positioned by a swing bolt and a lifting eye nut with a pin and a swing bolt ear plate, and the connection is sealed with an O-ring. When it is necessary to clean the raw materials in the reactor and overhaul the equipment, first open the bolts and nuts connecting and positioning the fixing device, then separate the upper and lower parts of the cylinder 4 by the hydraulic lifting device 9, and disassemble the stirring devices and stirring baffles 13 in the lower half of the cylinder 4; then clean the raw materials and clean the barrel. After cleaning and cleaning of the detachable parts, reassemble, and complete the overall closure by the hydraulic lifting device 9, and then restore the fixing and positioning device.

[0053] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A PAN precursor aqueous phase polymerization termination reactor, characterized in that: It includes a split-structured cylinder and a power device installed on the upper end of the cylinder. The upper end cover of the cylinder is provided with a feed inlet and a terminator inlet, the lower part of the cylinder is provided with a discharge port, and one side of the cylinder is provided with a hydraulic lifting device. The lower end of the hydraulic lifting device is fixed to the lower half of the cylinder, and the upper end is connected to the upper half of the cylinder. A stirring baffle and a central stirring shaft are arranged in the cylinder. The central stirring shaft is driven by the power device. A central stirring device is installed on the central stirring shaft and is connected to a planetary stirring device. The central stirring device stirs the material along the axial direction of the central stirring shaft, and the planetary stirring device rotates around the axial direction of the central stirring shaft and can perform self-rotation stirring and scrape the material.

2. The PAN precursor aqueous phase polymerization termination reactor according to claim 1, characterized in that: The planetary stirring device includes a plurality of planetary gears and a central gear plate fixedly mounted on the inner wall of the lower half of the cylinder body, a planetary shaft is fixed at the bottom of the plurality of planetary gears, a spiral belt stirring head or a scraper is arranged on the planetary shaft, the central stirring shaft and the planetary shaft are connected by an axial positioning ring, the central stirring shaft is located at the center of the central gear plate, and the plurality of planetary gears are respectively meshed with the central gear plate.

3. The PAN precursor aqueous phase polymerization termination reactor according to claim 2, characterized in that: U-shaped brackets are arranged around the central gear plate, and a slot cooperating with the U-shaped bracket is arranged on the inner side wall of the lower half of the cylinder.

4. The PAN precursor aqueous phase polymerization termination reactor according to claim 3, characterized in that: There are four planetary gears, which are evenly arranged on the inner side of the central gear disk along the circumference. There are two scrapers and two spiral-belt stirring heads, which are relatively arranged. The axial positioning ring includes a main shaft ring and four radially symmetrical side shaft rings connected thereto. The main shaft ring is sleeved on the central stirring shaft sleeve, and the side shaft rings are sleeved on the planetary shaft.

5. The PAN precursor aqueous phase polymerization termination reactor according to claim 2, characterized in that: The central stirring device comprises a middle four-blade stirrer and a bottom four-blade stirrer located in the middle and bottom of the central stirring shaft. The middle four-blade stirrer, the bottom four-blade stirrer and the planetary stirring device are staggered and do not contact each other.

6. The PAN precursor aqueous phase polymerization termination reactor according to claim 1, characterized in that: The upper and lower parts of the cylinder are both provided with stirring baffles, the stirring baffles adopt a raised streamlined structure, the inside of the baffles is hollow, and the ratio of the top height of the raised part to the length of the fixed end of the stirring baffle is in the range of 5:1 to 10:

1.

7. The PAN precursor aqueous phase polymerization termination reactor according to claim 6, characterized in that: A heat exchange medium is introduced into the hollow area inside the stirring baffle, and the thickness of the stirring baffle is 0.5-2 mm.

8. The PAN precursor aqueous phase polymerization termination reactor according to claim 1, characterized in that: A cooling jacket is arranged outside the cylinder, a heat exchange medium is introduced into the cooling jacket, the jacket inlet is located below the cooling jacket, the jacket outlet is located above the cooling jacket, and the angle between the jacket inlet and the jacket outlet is 180°.

9. The PAN precursor aqueous phase polymerization termination reactor according to claim 1, characterized in that: An emergency discharge port is arranged at the middle position of the bottom of the cylinder, and a water inlet, a vent port, a helium port, a pressure gauge port, a quick outlet port and a sight glass are arranged on the top cover of the upper end of the cylinder.

10. The PAN precursor aqueous phase polymerization termination reactor according to claim 9, characterized in that: Control valves are arranged inside the discharge port and the emergency discharge port.

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