A steam heated drying roll, dryer

Abstract

This invention provides a steam-heated drying roller and a dryer, relating to the field of carbon fiber technology, to solve one of the technical problems of poor uniformity in the densification degree of dried carbon fiber precursor and unstable precursor quality. The steam-heated drying roller is used for drying carbon fiber precursor. The drying roller includes a roller cylinder and a roller shaft for driving the roller cylinder to rotate. The roller cylinder includes a cylindrical body and a first end cap and a second end cap located at both ends of the cylindrical body. The second end cap has a through hole for the roller shaft to pass through. One end of the roller shaft is located outside the cylindrical body, and the other end of the roller shaft extends through the through hole into the interior of the cylindrical body. The drying roller also includes a steam generator and a rotary joint. The roller shaft is connected to the steam generator through the rotary joint. The roller shaft has an axially extending steam channel, which communicates with the steam generator through the steam channel of the rotary joint. This steam-heated drying roller can improve the uniformity of the densification degree of dried carbon fiber precursor.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber technology, and in particular to a steam-heated drying roller and a dryer. Background Technology

[0002] In the production of carbon fiber precursor, after the precursor is oiled, it must undergo drying and densification to dry the oil before entering the steam drawing chamber for high-ratio drawing. To ensure that the carbon fiber precursor is fully dried, the dryer mostly uses steam heating, and the steam-heated drying roller is the core component of the dryer.

[0003] The temperature uniformity of the steam-heated drying roller directly determines the consistency of the moisture content of the raw yarn, which ultimately leads to different degrees of drying and densification of each bundle of raw yarn. This can cause yarn breakage during high-ratio drawing and has a significant impact on the stable operation of the raw yarn. Summary of the Invention

[0004] The purpose of this invention is to provide a steam-heated drying roller and a dryer to solve one of the technical problems of poor uniformity in the degree of densification of carbon fiber precursor and unstable precursor quality.

[0005] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, embodiments of the present invention provide a steam-heated drying roller for drying carbon fiber filaments. The drying roller includes a roller and a roller shaft for driving the roller to rotate. The roller includes a cylindrical body and a first end cap and a second end cap covering both ends of the cylindrical body. The second end cap has a through hole through which the roller passes, one end of the roller is located outside the cylinder, and the other end of the roller extends through the through hole into the interior of the cylinder.

[0006] According to at least one embodiment of the present invention, the drying roller further includes a steam generator and a rotary joint, and the roller shaft is connected to the steam generator via the rotary joint.

[0007] According to at least one embodiment of the present invention, the roller has an axially extending steam passage that communicates with the steam generator via the rotary joint.

[0008] According to at least one embodiment of the present invention, the roller also has at least one radially extending steam port, through which the steam channel communicates with the cavity of the cylinder.

[0009] According to at least one embodiment of the present invention, the number of steam ports is multiple, and the multiple steam ports are arranged circumferentially along the roller shaft.

[0010] According to at least one embodiment of the present invention, the drying roller further includes a siphon tube.

[0011] According to at least one embodiment of the present invention, the siphon tube has a first tube segment and a second tube segment connected together; The end of the first pipe segment furthest from the second pipe segment is close to the inner wall surface of the cavity; The end of the second pipe segment furthest from the first pipe segment passes through the steam passage and extends to the outside of the cavity.

[0012] According to at least one embodiment of the present invention, the first pipe segment is perpendicular to the second pipe segment.

[0013] According to at least one embodiment of the present invention, the end of the first pipe segment away from the second pipe segment faces the bottom wall surface of the cavity.

[0014] According to at least one embodiment of the present invention, the drying roller further includes a partition disposed in the cylinder body, the partition dividing the cavity of the cylinder body into a first cavity segment and a second cavity segment distributed along the axial direction; one end of the roller shaft is welded to the partition, and the partition is welded to the cylinder body; The first cavity segment and the second cavity segment have the same axial length.

[0015] According to at least one embodiment of the present invention, at least one notch adjacent to the inner wall surface of the cylinder is provided on the partition plate; There are multiple gaps, which are arranged circumferentially along the partition.

[0016] According to at least one embodiment of the present invention, the steam port is located on the roller near the partition and in the second cavity section.

[0017] According to at least one embodiment of the present invention, the first pipe segment is located in the first cavity segment, and the diameter of the second pipe segment is smaller than the diameter of the steam passage.

[0018] According to at least one embodiment of the present invention, a first end cap is detachably mounted on the cylinder.

[0019] According to at least one embodiment of the present invention, there are two partitions, which divide the cavity of the cylinder into a first cavity segment, a second cavity segment, and a third cavity segment distributed along the axial direction. One end of the roller passes through the partition separating the second and third cavities and is connected to the partition separating the first and second cavities.

[0020] According to at least one embodiment of the present invention, the first pipe section is located in the first cavity section, and multiple sets of steam ports are located in the second cavity section and the third cavity section, respectively.

[0021] In a second aspect, embodiments of the present invention provide a steam-heated dryer, including a steam generator, a rotary joint, and the drying roller described in the first aspect; The drying roller is connected to the steam generator via the rotary joint.

[0022] In one or more technical solutions provided in the exemplary embodiments of the present invention, at least one of the following beneficial effects can be achieved.

[0023] An exemplary embodiment of the present invention provides a steam-heated drying roller, comprising a roller and a roller shaft for driving the roller to rotate. The roller includes a cylindrical body and a first end cap and a second end cap covering both ends of the cylindrical body. The second end cap has a through hole for the roller shaft to pass through. One end of the roller shaft is located outside the cylindrical body, and the other end of the roller shaft extends through the through hole into the interior of the cylindrical body. The cavity of the cylindrical body is divided into a first cavity segment and a second cavity segment by a partition. The end of the roller shaft located inside the cavity is welded to the partition. The axially extending steam channel of the roller shaft introduces steam into the first cavity segment through an opening in the partition and introduces steam into the second cavity segment through a steam port located in the second cavity segment, thereby performing secondary distribution of steam to ensure temperature uniformity. At the same time, the notch in the partition allows steam to form a dynamic equilibrium flow between the first cavity segment and the second cavity segment, effectively suppressing the temperature gradient.

[0024] Furthermore, when the notch on the partition rotates to the lowest point, it serves as a condensate connection channel between the first and second chambers, allowing the condensate to flow out in a timely manner. When the notch rotates to other phases, it becomes a dynamic pressure equalization channel for steam exchange between the first and second chambers, effectively balancing the pressure of the two chambers and suppressing the thermal stress concentration caused by uneven steam distribution, thereby significantly reducing the temperature difference on the surface of the roller.

[0025] Furthermore, the connection between the partition and the cylinder is refined into a welded connection, and radial reinforcing ribs are added at the weld between the partition and the cylinder to evenly distribute the thermal expansion stress along the ribs. The welded connection between the partition and the cylinder forms a rigid integrated structure, which significantly suppresses thermal bulging in the middle of the cylinder. This ensures that the dimensional deviation between the middle and the two ends of the cylinder is controlled within the required range under long-term high temperature and high pressure working conditions, thereby ensuring that the subsequent drawing quality of the carbon fiber precursor meets the consistency requirements. Attached Figure Description

[0026] The accompanying drawings illustrate exemplary embodiments of the invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0027] Figure 1 This is a schematic cross-sectional view of a drying roller according to an embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of the AA cross-sectional structure; Figure 3 yes Figure 1Enlarged view of section B; Figure 4 This is a schematic diagram of the cross-sectional structure of a sliding bearing according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of a drying roller in related technologies.

[0028] Figure label: 10. Cylinder body; 11. First cavity section; 111. First end cap; 12. Second cavity section; 121. Second end cap; 20. Roller shaft; 21. Steam passage; 22. Steam inlet; 30. Rotary joint; 31. First pipe section; 32. Second pipe section; 40. Partition; 41. Notch; 42. Sliding bearing. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0030] Example 1 In the production of PAN-based carbon fiber, in order to ensure that the carbon fiber precursor is fully dried, the surface temperature of the heating roller must reach above 180℃, and the surface temperature uniformity of the heating roller must be high (required to be less than ±0.5℃).

[0031] Figure 5 This is a schematic cross-sectional view of a drying roller in related technologies. For example... Figure 5 As shown, in related technologies, steam-heated drying rollers generally use a rotary joint 30 to introduce steam into the roller cavity, transferring the heat energy of the steam to the surface of the roller body 10. Since the steam enters from the end cap on one side of the roller body 10, although the steam is in a turbulent state after entering the roller body 10, the temperature on the steam inlet side of the roller body 10 is significantly higher than the temperature on the other side, causing the temperature uniformity of the surface of the roller body 10 to exceed the requirements for use, which affects the degree of densification of the raw yarn during drying.

[0032] Figure 1 This is a schematic cross-sectional view of a drying roller according to an embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of the AA cross-sectional structure. Combined with... Figure 1 and Figure 2 As shown, the steam-heated drying roller provided in the exemplary embodiment of the present invention is used for drying carbon fiber filaments. The drying roller includes a roller and a roller shaft 20 for driving the roller to rotate. The roller includes a cylinder 10 and a first end cap 111 and a second end cap 121 covering both ends of the cylinder 10. The second end cap 121 has a through hole for the roller shaft 20 to pass through. One end of the roller shaft 20 is located outside the cylinder 10, and the other end of the roller shaft 20 extends through the through hole into the interior of the cylinder 10.

[0033] To address the technical problem of poor temperature uniformity caused by a significantly higher temperature on the steam inlet side of the steam-heated drying roller cylinder 10 compared to the other side, the drying roller also includes a partition 40 disposed within the cylinder 10. The partition 40 divides the cavity of the cylinder 10 into a first cavity segment 11 and a second cavity segment 12 distributed along the axial direction. One end of the roller shaft 20 is welded to the partition 40, and the partition 40 is welded to the cylinder 10.

[0034] For example, the partition 40 has at least one notch 41 adjacent to the inner wall surface of the cylinder 10.

[0035] The roller 20 has an axially extending steam passage 21, which is connected to a steam generator via a rotary joint 30. The roller 20 also has at least one radially extending steam port 22, which is connected to the cavity of the cylinder 10 via the steam passage 21.

[0036] In actual use, the roller 20 continuously drives the cylinder 10 to rotate under the drive of the drive device. The hot steam generated by the steam generator enters the cavity of the cylinder 10 through the rotary joint 30, the steam channel 21 of the roller 20 and the radially extending steam port 22.

[0037] Specifically, the cavity of the cylinder 10 is divided into a first cavity section 11 and a second cavity section 12 by a partition plate 40. The end of the roller 20 located in the cavity is welded to the partition plate 40. The axially extending steam channel 21 of the roller 20 introduces steam into the first cavity section 11 through the opening on the partition plate 40, and introduces steam into the second cavity section 12 through the steam port 22 located in the second cavity section 12, thereby distributing the steam in a secondary manner to ensure temperature uniformity.

[0038] At the same time, the notch 41 on the partition 40 allows steam to flow dynamically and evenly between the first chamber 11 and the second chamber 12, effectively suppressing the temperature gradient.

[0039] For example, the number of notches 41 on the partition 40 can be multiple, and they are evenly distributed along the circumference of the partition 40, so that the steam flow path between the first chamber section 11 and the second chamber section 12 is symmetrical.

[0040] For example, the number of steam ports 22 can also be multiple, and they are evenly distributed along the circumference of the roller shaft 20, so that the steam diffuses evenly in the first chamber section 11 and the second chamber section 12, further improving the heat exchange efficiency. When the roller rotates, the notch 41 automatically adjusts the pressure difference between the first chamber section 11 and the second chamber section 12 and the condensate discharge path according to the position change, so that the temperature fluctuation under high temperature conditions is less than ±0.5℃.

[0041] Continue as Figure 2As shown, when the notch 41 on the partition 40 rotates to the lowest point, it serves as a condensate water connection channel between the first chamber 11 and the second chamber 12, allowing the condensate water to flow out in a timely manner. When the notch 41 rotates to other phases, it becomes a dynamic pressure equalization channel for steam exchange between the first chamber 11 and the second chamber 12, effectively balancing the pressure of the two chambers and suppressing the thermal stress concentration caused by uneven steam distribution, thereby significantly reducing the surface temperature difference of the roller body 10.

[0042] Example 2 To address the problem of reduced heat transfer efficiency caused by condensation after steam enters the cavity and undergoes heat exchange, the exemplary embodiment of this invention adds a siphon tube structure based on embodiment two.

[0043] The condensate formed after heat transfer is discharged through a siphon pipe installed on the rotary joint 30, or discharged from the first end cap 111 side of the cylinder 10 through a siphon pipe.

[0044] For example, the siphon tube has a first tube segment 31 and a second tube segment 32 connected together; the end of the first tube segment 31 away from the second tube segment 32 is close to the inner wall of the cavity; the end of the second tube segment 32 away from the first tube segment 31 passes through the steam passage 21 and extends to the outside of the cavity.

[0045] The first pipe segment 31 is perpendicular to the second pipe segment 32, wherein the end of the first pipe segment 31 furthest from the second pipe segment 32 faces the bottom wall of the cavity. That is, the open end of the first pipe segment 31 always faces downward.

[0046] This structure ensures that the siphon opening is always at the lowest point of the cavity. No matter what angle the roller rotates to, the condensate will always flow to the siphon along the shortest path under the action of gravity, avoiding water accumulation that could lead to local temperature anomalies. The phase control of the notch 41 is coupled with the roller speed to form an adaptive thermal management mechanism, which can maintain a surface temperature difference within ±0.5℃ under different operating conditions.

[0047] For example, the first section 31 of the siphon is located in the first cavity 11, and the second section 32 of the siphon passes through the steam channel 21 of the roller 20 and extends to the outside of the rotary joint 30; the inner diameter of the second section 32 is equal to the inner diameter of the first section 31, and the outer diameter of the second section 32 is smaller than the inner diameter of the steam channel 21, so that an annular channel is formed between the siphon and the steam channel 21, so that steam continuously enters the first cavity 11 through the annular channel and enters the second cavity 12 through the steam port 22 in the second cavity 12, thereby realizing synchronous steam supply to the first cavity 11 and the second cavity 12.

[0048] Figure 3 yes Figure 1 Enlarged view of section B; Figure 4This is a schematic cross-sectional view of the sliding bearing 42 according to an embodiment of the present invention. (Combined with...) Figures 1-4 As shown, one end of the second pipe section 32 is mounted on the rotary joint 30, and the other end is connected to the part of the roller shaft 20 near the partition plate 40 via a sliding bearing 42. The sliding bearing 42 has four fan-shaped steam channels 21, allowing steam to enter the first chamber section 11. Based on this, the opening of the first pipe section 31 always faces downwards during the rotation of the roller shaft 20.

[0049] To facilitate the installation and maintenance of the siphon tube, the first end cap 111 is detachably mounted on the cylinder 10. For example, the first end cap 111 can be quickly attached to the cylinder 10 via bolt connection. This detachable structure also facilitates the periodic cleaning of deposits on the inner wall of the siphon tube, ensuring that the siphon efficiency does not decrease during long-term operation.

[0050] Example 3 Under the combined effects of high temperature and pressure, after a period of use, the diameter of the middle part of the cylinder 10 will be slightly larger than that of other parts of the cylinder 10, which will cause the draw ratio of the carbon fiber filament in the middle part to be different from that in other parts, and will also affect the quality of the filament.

[0051] To address the issue of uneven diameter of the cylinder 10 affecting the quality of carbon fiber precursor, based on Embodiment 1 or Embodiment 2, this invention further refines the connection between the partition plate 40 and the cylinder 10 into a welded connection, and adds radial reinforcing ribs at the weld between the partition plate 40 and the cylinder 10. This allows thermal expansion stress to be evenly distributed along the ribs, and the welded connection between the partition plate 40 and the cylinder 10 forms a rigid integrated structure, significantly suppressing thermal bulging in the middle of the cylinder 10. This ensures that the dimensional deviation between the middle and both ends of the cylinder 10 is controlled within the required range under long-term high-temperature and high-pressure working conditions, thereby ensuring that the subsequent drawing quality of the carbon fiber precursor meets the consistency requirements.

[0052] Optionally, there are two partitions 40, which divide the cavity of the cylinder 10 into a first cavity section 11, a second cavity section 12, and a third cavity section distributed along the axial direction. One end of the roller 20 passes through the partition 40 separating the second cavity section 12 and the third cavity section and is connected to the partition 40 separating the first cavity section 11 and the second cavity section 12. The first pipe section 31 is located in the first cavity section 11, and the steam port 22 is located in the second cavity section 12.

[0053] The partition 40 separating the first cavity 11 and the second cavity 12 is defined as the first partition 40, and the partition 40 separating the second cavity 12 and the third cavity is defined as the second partition 40. The first partition 40 is welded to the roller shaft 20. The second partition 40 has a through hole in the center for the roller shaft 20 to pass through. The roller shaft 20 has a set of steam ports 22 in the second cavity 12 and another set of steam ports 22 in the third cavity. The steam channel 21 of the roller shaft 20 has an opening on the first partition 40 that communicates with the first cavity 11.

[0054] The first section 31 of the siphon extends to the bottom of the first cavity section 11, and the second section 32 passes through the steam channel 21 of the roller 20 to the outside of the cylinder 10.

[0055] With the design of the first and second partition plates 40 dividing the chambers and the dual steam inlets 22, steam can be injected into the first chamber 11, the second chamber 12, and the third chamber simultaneously to achieve uniform heating in three sections. At the same time, the notches 41 on the first and second partition plates 40 are set one-to-one. When the two notches 41 are rotated to the lowest point, they form a condensate guide channel connecting the three chambers to ensure that the condensate in each chamber is discharged synchronously. When the notches 41 are in other phases, they serve as steam interconnection fine-tuning ports to dynamically balance the pressure difference between the three chambers and further achieve uniform heat distribution.

[0056] Meanwhile, the rigid support structure formed by welding the first partition 40 and the second partition 40 to the cylinder 10 effectively suppresses the bulging deformation in the middle of the cylinder 10 caused by thermal expansion; the three-chamber coordinated heating and dynamic pressure balance mechanism improves the temperature uniformity of the cylinder 10, thereby achieving consistent drying of carbon fiber precursor and improving the quality of carbon fiber precursor.

[0057] Example 4 An exemplary embodiment of the present invention also provides a steam-heated dryer, including a steam generator, a rotary joint 30, and any one of the drying rollers in Embodiments 1 to 3; The drying roller is connected to the steam generator via a rotary joint 30.

[0058] The aforementioned light steam heating dryer has the same technical advantages over existing technologies as the aforementioned drying roller, and will not be repeated here.

[0059] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A steam-heated drying roller, characterized in that, For drying carbon fiber precursor, the drying roller includes a roller and a roller shaft for driving the roller to rotate. The roller includes a cylinder and a first end cap and a second end cap covering both ends of the cylinder. The second end cap has a through hole through which the roller passes, one end of the roller is located outside the cylinder, and the other end of the roller extends through the through hole into the interior of the cylinder.

2. The drying roller according to claim 1, characterized in that, The drying roller also includes a steam generator and a rotary joint, and the roller shaft is connected to the steam generator through the rotary joint.

3. The drying roller according to claim 2, characterized in that, The roller has an axially extending steam channel, which is connected to the steam generator via the rotary joint.

4. The drying roller according to claim 3, characterized in that, The roller also has at least one radially extending steam port, through which the steam channel communicates with the cavity of the cylinder.

5. The drying roller according to claim 4, characterized in that, The number of steam ports is multiple, and the multiple steam ports are arranged circumferentially along the roller shaft.

6. The drying roller according to claim 5, characterized in that, The drying roller also includes a siphon tube.

7. The drying roller according to claim 6, characterized in that, The siphon tube has a first tube segment and a second tube segment connected together. The end of the first pipe segment furthest from the second pipe segment is close to the inner wall surface of the cavity; The end of the second pipe segment furthest from the first pipe segment passes through the steam passage and extends to the outside of the cavity.

8. The drying roller according to claim 7, characterized in that, The first pipe segment is perpendicular to the second pipe segment.

9. The drying roller according to claim 7, characterized in that, The end of the first pipe segment furthest from the second pipe segment faces the bottom wall of the cavity.

10. A steam-heated dryer, characterized in that, Includes a steam generator, a rotary joint, and a drying roller as described in any one of claims 1-9; The drying roller is connected to the steam generator via the rotary joint.

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