A production apparatus for preparing lignin-based carbon fibers by meltblowing.

Abstract

This utility model discloses a production apparatus for preparing lignin-based carbon fiber by meltblowing, comprising: a workbench with a support assembly mounted on its bottom surface and a conveyor belt mounted on its top; a spinning mechanism including side plates symmetrically fixed to the top surface of the workbench, a lifting frame vertically slidably connected between the side plates, a spinning plate mounted at the bottom of the lifting frame, and a lifting assembly mounted on the side plates; a cooling mechanism including two sets of vertical plates symmetrically fixed to the top surface of the workbench, an air cooler fixed between the two sets of vertical plates, the air cooler being positioned above the conveyor belt, an annular baffle rotatably connected between the two sets of vertical plates, a partition plate being provided on the inner side of the annular baffle, and a transmission assembly mounted on one set of vertical plates; and a control system. This utility model is adaptable to the production of lignin-based carbon fiber of different specifications, has strong adaptability, and reduces the equipment investment costs for enterprises producing multiple product categories.

Description

Technical Field

[0001] This utility model relates to the field of carbon fiber preparation technology, and in particular to a production apparatus for preparing lignin-based carbon fibers by meltblowing. Background Technology

[0002] Carbon fiber, as a new type of high-strength, low-density, high-performance fiber material, has become a key basic material in strategic emerging fields such as aerospace, high-end equipment manufacturing, new energy vehicles, and energy storage devices due to its excellent mechanical properties, corrosion resistance, and high-temperature resistance. Traditional carbon fiber is mostly prepared from raw materials such as polyacrylonitrile (PAN) and pitch, with PAN-based carbon fiber accounting for more than 90%. However, the high cost of PAN raw materials, the complex synthesis process, and the reliance on non-renewable fossil resources result in high overall production costs for carbon fiber, limiting its large-scale application in the civilian sector.

[0003] Meltblowing, as a highly efficient fiber forming process, boasts advantages such as high production efficiency, relatively simple equipment structure, and the ability to achieve continuous production, and has been widely used in nonwoven fabrics, microfiber preparation, and other fields. Introducing meltblowing technology into the preparation of lignin-based carbon fibers allows for the high-temperature melting of lignin raw materials, high-speed extrusion through a spinneret to form fibers, followed by cooling, shaping, and subsequent carbonization processes to obtain carbon fiber products. However, existing meltblowing equipment suffers from poor cooling and shaping effects when adapted for lignin-based carbon fiber preparation. Lignin meltblown fibers require rapid and uniform cooling after extrusion to complete shaping; otherwise, fiber adhesion, shrinkage, and deformation can easily occur, directly affecting the fiber strength in subsequent carbonization processes. Existing cooling mechanisms mostly employ a single, fixed air-cooling structure, with unadjustable airflow and cooling range. This prevents dynamic adjustment of cooling intensity based on the diameter of the lignin fibers and production speed, resulting in uneven cooling and poor fiber shaping in some areas.

[0004] In summary, given the process characteristics of meltblown lignin-based carbon fiber preparation, developing a production device with flexible adjustable spinneret height, dynamic adaptation to cooling intensity, and integrated control is a key requirement for promoting the industrialization and large-scale production of lignin-based carbon fiber. Utility Model Content

[0005] The purpose of this invention is to provide a production apparatus for preparing lignin-based carbon fibers by melt-blowing, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, this utility model provides the following solution: This utility model provides a production apparatus for preparing lignin-based carbon fibers by meltblowing, comprising:

[0007] A workbench, the bottom surface of which is equipped with a support assembly, and the top surface of which is equipped with a conveyor belt;

[0008] The spinning mechanism includes side plates symmetrically fixed to the top surface of the workbench, a lifting frame vertically slidably connected between the two side plates, a spinning plate installed at the bottom of the lifting frame, and a lifting assembly installed on the side plates. The lifting assembly is used to control the lifting of the lifting frame.

[0009] A cooling mechanism includes two sets of vertical plates, which are symmetrically fixed to the top surface of the workbench and located in front of the vertical plates. An air cooler is fixed between the two sets of vertical plates and is located above the conveyor belt, with its air outlet corresponding to the top surface of the conveyor belt. An annular baffle is rotatably connected between the two sets of vertical plates and is sleeved on the outside of the air cooler. A partition is provided on the inner side of the annular baffle, dividing it into four areas. Each of the four areas has ventilation holes of different densities on its sidewall. A transmission assembly is installed on one set of vertical plates and engages with the annular baffle.

[0010] A control system is used to regulate the operation of the overall control device.

[0011] According to the production apparatus for preparing lignin-based carbon fiber by meltblowing provided by this utility model, the lifting assembly includes a vertically arranged screw, a vertically opened groove on the side plate, a T-shaped slider slidably connected in the groove, the T-shaped slider being fixedly connected to the lifting frame, the screw being vertically rotatably connected to the side of the worktable, the screw passing through the T-shaped slider and threadedly connected to the T-shaped slider, a lifting motor being fixed to the side of the worktable, and the lifting motor being axially connected to the screw.

[0012] According to the production apparatus for preparing lignin-based carbon fibers by meltblowing provided by this utility model, the transmission component includes a transmission motor, the transmission motor is fixed on the top surface of the vertical plate, the output shaft of the transmission motor is fixed with a gear, and an external gear ring is fixed on the outer wall of the annular baffle, the external gear ring meshing with the gear.

[0013] According to the production apparatus for preparing lignin-based carbon fibers by meltblowing provided by this utility model, a temperature sensor is installed on the vertical plate, and the temperature sensor is connected to the control system.

[0014] According to the production apparatus for preparing lignin-based carbon fibers by meltblowing provided by this utility model, the bottom of the workbench is equipped with casters, and the casters are arranged in several sets.

[0015] According to the production apparatus for preparing lignin-based carbon fibers by meltblowing provided by this utility model, the support assembly is provided in several sets at the bottom of the workbench. The support assembly includes a support bolt and a base. The support bolt is vertically threaded to the bottom of the workbench, and the base is fixed to the bottom of the support bolt.

[0016] According to the production apparatus for preparing lignin-based carbon fibers by melt-blowing method provided by this utility model, the conveyor belt is arranged with several comb teeth.

[0017] The present invention discloses the following technical effects:

[0018] The spinneret mechanism adopts an adjustable structure of "lifting frame + lifting components". Combined with the precise control of the control system, it can finely adjust the distance between the spinneret and the conveyor belt in real time according to the viscosity and flowability changes of the lignin melt (the adjustment accuracy can reach the millimeter level). This solves the problem of large fiber diameter fluctuations caused by fixed spinnerets or manual adjustment in existing equipment.

[0019] The cooling mechanism switches between different densities of ventilation holes by rotating the annular baffle. Combined with the air volume adjustment of the air cooler, the cooling intensity and coverage can be flexibly adjusted according to the fiber diameter (coarse / fine) and conveying speed (fast / slow): high-density ventilation holes are suitable for rapid cooling of coarse fibers, while low-density ventilation holes are suitable for comprehensive cooling of high-speed conveyed fibers. The baffle design further ensures cooling uniformity and effectively reduces defects such as fiber adhesion, shrinkage and deformation.

[0020] The overall structure of the device is based on the workbench, with modular integration of the spinning and cooling mechanisms. It occupies a small area and can be adapted to the production of lignin-based carbon fibers of different specifications by replacing the spinning plates with different orifice diameters and adjusting the density of the ventilation holes in the annular baffle. It has strong adaptability and reduces the equipment investment costs for enterprises to produce multiple products. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a cross-sectional view of the main view of the production apparatus for preparing lignin-based carbon fibers by meltblowing method according to the present invention.

[0023] Figure 2 This is a left view of the main view of the production apparatus for preparing lignin-based carbon fibers by meltblowing according to the present invention.

[0024] The components include: 1. Workbench; 2. Conveyor belt; 3. Side plate; 4. Lifting frame; 5. Vertical plate; 6. Air cooler; 7. Annular baffle; 8. Partition plate; 9. T-shaped slider; 10. Screw; 11. Lifting motor; 12. Drive motor; 13. Gear; 14. External gear ring. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Reference Figures 1-2 This utility model provides a production apparatus for preparing lignin-based carbon fibers by meltblowing, comprising:

[0028] Workbench 1, with a support assembly installed on the bottom surface of workbench 1 and a conveyor belt 2 installed on the top of workbench 1;

[0029] The spinning mechanism includes side plates 3 symmetrically fixed on the top surface of the workbench 1. A lifting frame 4 is vertically slidably connected between the two side plates 3. A spinning plate is installed at the bottom of the lifting frame 4. A lifting assembly is installed on the side plates 3. The lifting assembly is used to control the lifting of the lifting frame 4.

[0030] The cooling mechanism includes two sets of vertical plates 5, which are symmetrically fixed on the top surface of the workbench 1 and located in front of the vertical plates 5. A fan cooler 6 is fixed between the two sets of vertical plates 5. The fan cooler 6 is located above the conveyor belt 2, and the air outlet of the fan cooler 6 corresponds to the top surface of the conveyor belt 2. An annular baffle 7 is rotatably connected between the two sets of vertical plates 5. The annular baffle 7 is sleeved on the outside of the fan cooler 6. A partition 8 is provided on the inner side of the annular baffle 7, which divides the annular baffle 7 into four areas. The side walls of the four areas are provided with ventilation holes of different densities. A transmission component is installed on one set of vertical plates 5, and the transmission component is in transmission cooperation with the annular baffle 7.

[0031] The control system is used to regulate the operation of the overall control device.

[0032] Before starting the device, the process parameters are initialized through the control system: based on the molecular weight distribution, melt viscosity and other characteristics of the lignin raw material, the conveying speed of the conveyor belt 2, the initial height of the spinneret, and the initial air volume of the air cooler 6 are preset. At the same time, the initial position of the annular baffle 7 is adjusted through the transmission component so that the area of ​​the ventilation holes of the corresponding density is aligned with the air outlet of the air cooler 6 to ensure that the cooling intensity matches the initial process requirements.

[0033] The pretreated lignin raw material is fed into a matching melting device. After being melted at high temperature to form a uniform lignin melt, the melt is conveyed to the spinneret of the spinneret mechanism. At this time, if the spinning effect needs to be adjusted during production, the control system can drive the lifting component on the side plate 3, causing the lifting frame 4 to slide vertically along the side plate 3, precisely adjusting the distance between the spinneret and the conveyor belt 2 below (for example, appropriately increasing the distance when the viscosity increases to avoid fiber accumulation; decreasing the distance when the viscosity decreases to ensure uniform fiber diameter). The melt is ejected at high speed through the spinneret holes of the spinneret, forming continuous lignin meltblown fibers above the conveyor belt 2. The ejected lignin meltblown fibers are conveyed forward with the conveyor belt 2 and enter the working area of ​​the cooling mechanism. At this time, the air cooler 6 is started, and cold air is blown onto the fibers on the conveyor belt 2 through the ventilation holes on the annular baffle 7, completing the initial cooling and shaping. If the cooling intensity needs to be adjusted during production (e.g., increased cooling is required for larger fiber diameters, or the cooling range needs to be expanded for faster conveying speeds), the control system can activate the transmission components on the vertical plate 5, causing the annular baffle 7 to rotate around the vertical plate 5. This switches the areas of ventilation holes with different densities to align with the air outlet: the high-density ventilation hole area enhances the penetration of cold air (suitable for rapid cooling of coarse-diameter fibers), while the low-density ventilation hole area expands the cooling coverage (suitable for high-speed conveyed fibers). The partition 8 prevents airflow interference between ventilation holes in different areas, ensuring uniform cooling and effectively preventing fiber adhesion, shrinkage, and deformation. After cooling and shaping, the lignin fibers are continuously conveyed to the end of the device by the conveyor belt 2, directly entering subsequent drawing, carbonization, and other processes, achieving continuous connection of the entire lignin-based carbon fiber preparation process. During production, the control system collects parameters such as spinneret height, airflow of the air cooler 6, and conveyor belt speed in real time, and dynamically adjusts each mechanism through a preset algorithm to ensure stable operation throughout the entire process.

[0034] The design is further optimized. The lifting assembly includes a vertically arranged screw 10, a vertically opened slide groove on the side plate 3, a T-shaped slider 9 slidably connected in the slide groove, the T-shaped slider 9 is fixedly connected to the lifting frame 4, the screw 10 is vertically rotatably connected to the side of the worktable 1, the screw 10 passes through the T-shaped slider 9 and is threadedly connected to the T-shaped slider 9, and a lifting motor 11 is fixed on the side of the worktable 1, the lifting motor 11 is axially connected to the screw 10.

[0035] The lifting assembly uses screw 10 for precise adjustment. When the spinneret height needs to be adjusted, the control system drives the lifting motor 11 to operate, and the motor output shaft drives the screw 10 to rotate synchronously. Since the T-shaped slider 9 is threadedly connected to the screw 10, and the T-shaped slider 9 is restricted to the groove of the side plate 3 and cannot rotate, the rotational motion of the screw 10 is converted into the vertical linear motion of the T-shaped slider 9. The T-shaped slider 9 is rigidly connected to the lifting frame 4, which in turn drives the lifting frame 4 and the spinneret at the bottom to rise and fall stably along the groove, ultimately achieving precise control of the distance between the spinneret and the conveyor belt 2 (the adjustment accuracy is controlled by the screw pitch of the screw 10 and the motor speed).

[0036] Wear-resistant sliders (such as those made of polytetrafluoroethylene) are added to the contact area between the slide groove and the T-shaped slider 9 to reduce the increase in gap caused by long-term friction and reduce noise during lifting. Guide columns and guide sleeves can be added between the two sides of the lifting frame 4 and the side plate 3 to further improve the stability of the lifting process.

[0037] Mechanical limit blocks (such as rubber buffer blocks) are installed at both ends of the chute, and photoelectric sensors are provided. When the T-shaped slider 9 approaches the limit position, the control system automatically cuts off the power to the lifting motor 11 to prevent mechanical damage caused by overtravel.

[0038] The ordinary lifting motor 11 can also be upgraded to a servo motor, and with the encoder, height closed-loop control can be achieved, so that the height adjustment accuracy of the spinneret can be improved from the millimeter level to the 0.1 millimeter level, to meet more refined process requirements.

[0039] Further optimization of the scheme: the transmission component includes a transmission motor 12, which is fixed on the top surface of the vertical plate 5. The output shaft of the transmission motor 12 is fixed with a gear 13, and an external gear ring 14 is fixed on the outer wall of the annular baffle 7. The external gear ring 14 meshes with the gear 13.

[0040] The transmission assembly uses gear 13 to adjust the angle of the annular baffle 7. When the cooling intensity needs to be switched, the control system starts the transmission motor 12, and the motor output shaft drives the gear 13 to rotate. The gear 13 meshes with the outer toothed ring 14 on the outer wall of the annular baffle 7, transmitting the rotational motion of the motor to the annular baffle 7, causing the annular baffle 7 to rotate around the axis between the vertical plates 5. By controlling the forward and reverse rotation and the rotation angle of the motor, the areas of ventilation holes with different densities on the annular baffle 7 can be precisely switched to align with the air outlet of the air cooler 6, thereby achieving rapid switching of cooling intensity.

[0041] A planetary reducer is added between the drive motor 12 and the gear 13 to reduce the output speed while increasing the torque, avoid rotational jamming caused by the large weight of the annular baffle 7, and improve the angle adjustment accuracy (which can be controlled within ±1°).

[0042] A positioning detection device is set up: four positioning protrusions are set on the edge of the annular baffle 7, corresponding to the four ventilation hole areas. A proximity switch is installed on the upright plate 5. When the protrusion triggers the proximity switch, the control system confirms the current area position, achieves accurate positioning, and avoids the tediousness of manual calibration.

[0043] The design was further optimized by installing a temperature sensor on the vertical plate 5, which is connected to the control system.

[0044] Temperature sensors on the vertical plate 5 collect the air temperature and surface temperature of the lignin fiber in the cooling area in real time, and convert the temperature signal into an electrical signal and transmit it to the control system. The control system compares the measured temperature with the preset process temperature (set according to parameters such as fiber diameter and conveying speed). If the temperature deviation exceeds the threshold, it automatically adjusts the air volume of the air cooler 6 (increases the air volume when the temperature is too high and decreases the air volume when the temperature is too low) or switches the ventilation hole density of the annular baffle 7 through the transmission component (such as switching to a high-density hole area to enhance heat dissipation when the temperature is high), forming a closed-loop temperature control to ensure stable cooling and shaping effect.

[0045] Three sets of temperature sensors (inlet, middle, and outlet) are installed on the vertical plate 5 along the running direction of the conveyor belt 2 to monitor the temperature of the fibers entering the cooling zone, during the cooling process, and when leaving the cooling zone, forming a temperature gradient curve to provide a more comprehensive adjustment basis for the control system.

[0046] The design was further optimized by installing casters at the bottom of workbench 1, with several sets of casters.

[0047] Further optimization of the scheme: several sets of support components are set at the bottom of the workbench 1. The support components include support bolts and bases. The support bolts are vertically threaded to the bottom of the workbench 1, and the bases are fixed to the bottom of the support bolts.

[0048] The design was further optimized by arranging several comb teeth on conveyor belt 2.

[0049] Several comb teeth on the conveyor belt 2 are evenly distributed along the width direction of the conveyor belt 2. When the lignin meltblown fiber falls on the conveyor belt 2, the comb teeth can separate the continuous fiber layer into several independent fiber bundles, avoiding the formation of clumps due to mutual adhesion during the conveying process. At the same time, the comb teeth can comb the fiber arrangement direction, so that the fiber is neatly distributed along the running direction of the conveyor belt 2, reducing the problem of uneven cooling caused by fiber stacking during subsequent cooling, and laying the foundation for uniform heating in the carbonization stage.

[0050] A brush roller is installed on the return section (below) of conveyor belt 2, which contacts the comb teeth and automatically cleans the fiber debris entangled between the comb teeth as the conveyor belt 2 rotates, thus avoiding long-term accumulation that affects the performance.

[0051] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0052] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A production apparatus for producing a lignin-based carbon fiber by a melt-blowing method, characterized by comprising: a lignin-based carbon fiber production device; and a lignin-based carbon fiber collection device. include: A workbench (1) is provided with a support assembly on its bottom surface and a conveyor belt (2) is provided on its top surface. The spinning mechanism includes side plates (3) symmetrically fixed on the top surface of the workbench (1), a lifting frame (4) is vertically slidably connected between the two side plates (3), a spinning plate is installed at the bottom of the lifting frame (4), and a lifting assembly is installed on the side plates (3). The lifting assembly is used to control the lifting of the lifting frame (4). The cooling mechanism includes two sets of vertical plates (5), which are symmetrically fixed on the top surface of the workbench (1) and located in front of the vertical plates (5). A fan cooler (6) is fixed between the two sets of vertical plates (5). The fan cooler (6) is located above the conveyor belt (2), and the air outlet of the fan cooler (6) corresponds to the top surface of the conveyor belt (2). An annular baffle (7) is rotatably connected between the two sets of vertical plates (5). The annular baffle (7) is sleeved on the outside of the fan cooler (6). A partition (8) is provided on the inner side of the annular baffle (7). The partition (8) divides the annular baffle (7) into four areas, and ventilation holes of different densities are opened on the side walls of the four areas respectively. A transmission component is installed on one set of vertical plates (5), and the transmission component is in transmission cooperation with the annular baffle (7). A control system is used to regulate the operation of the overall control device.

2. The production device for preparing lignin-based carbon fibers by melt-blowing according to claim 1, characterized in that, The lifting assembly includes a vertically arranged screw (10), a vertically opened groove on the side plate (3), a T-shaped slider (9) slidably connected in the groove, the T-shaped slider (9) being fixedly connected to the lifting frame (4), the screw (10) being vertically rotatably connected to the side of the workbench (1), the screw (10) passing through the T-shaped slider (9) and being threadedly connected to the T-shaped slider (9), and a lifting motor (11) being fixed on the side of the workbench (1), the lifting motor (11) being axially connected to the screw (10).

3. The production device for preparing lignin-based carbon fibers by melt-blowing according to claim 1, characterized in that, The transmission assembly includes a transmission motor (12), which is fixed to the top surface of the vertical plate (5). The output shaft of the transmission motor (12) is fixed with a gear (13), and the outer wall of the annular baffle (7) is fixed with an external gear ring (14), which meshes with the gear (13).

4. The production apparatus for preparing lignin-based carbon fibers by meltblowing according to claim 1, characterized in that, A temperature sensor is installed on the upright plate (5), and the temperature sensor is connected to the control system.

5. The production device for preparing lignin-based carbon fibers by melt-blowing according to claim 1, characterized in that, The bottom of the workbench (1) is equipped with casters, and the casters are arranged in several sets.

6. The production device for preparing lignin-based carbon fibers by melt-blowing according to claim 1, characterized in that, The support assembly is provided in several groups at the bottom of the workbench (1). The support assembly includes a support bolt and a base. The support bolt is vertically threaded to the bottom of the workbench (1), and the base is fixed to the bottom of the support bolt.

7. The production device for preparing lignin-based carbon fibers by melt-blowing according to claim 1, characterized in that, The conveyor belt (2) is equipped with several comb teeth.

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