A seamless steel tube hot rolling post cooling bed uniform cooling system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DAYE SPECIAL STEEL CO LTD
- Filing Date
- 2023-12-21
- Publication Date
- 2026-07-21
Smart Images
Figure CN117583406B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of seamless steel pipe processing technology, and in particular to a uniform cooling bed system for hot-rolled seamless steel pipes. Background Technology
[0002] On a steel pipe production line, the cooling bed is an indispensable piece of production equipment and one of the most important pieces of equipment besides the main machine. It is used in both hot rolling lines and heat treatment lines for seamless steel pipes. Its function is to allow the hot-rolled or furnace-exited seamless steel pipes to gradually cool naturally or be externally cooled (according to specific requirements) during a slow lateral movement before being transferred to the next process. The lateral movement of the steel pipes on the cooling bed is generally achieved through the movement of the cooling bed surface itself, and the cooling effect is related to the type of cooling bed and the cooling method.
[0003] In existing technologies, the fans are usually stationary, blowing cold air along the axial direction of the seamless steel pipe to cool it. This often results in uneven cooling of the seamless steel pipe on the cooling bed. When the seamless steel pipe is cooled on the cooling bed, due to the different pipe diameters and wall thicknesses of different models, the stationary fans blowing cold air along the axial direction of the seamless steel pipe cannot achieve uniform cooling of the steel.
[0004] Therefore, there is a need for a uniform cooling system for seamless steel pipes after hot rolling, which can achieve uniform cooling of seamless steel pipes. Summary of the Invention
[0005] The purpose of this invention is to provide a uniform cooling system for hot-rolled seamless steel pipes. The method involves passing the hot-rolled seamless steel pipe through a first cooling bed and a second cooling bed for cooling. By combining the thermal conductivity of different seamless steel pipe components and the stress release characteristics of the seamless steel pipe during the cooling process, the blowing angle of the first axial flow fan and the height of the second axial flow fan are adjusted, along with the reverse chain running speed V, to achieve uniform cooling of the seamless steel pipe after hot rolling.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] A uniform cooling system for a seamless steel pipe after hot rolling includes a first conveyor roller, a second conveyor roller, a first cooling bed, and a second cooling bed. The first conveyor roller is connected to the inlet of the first cooling bed, and the second conveyor roller is connected to both the outlet of the first cooling bed and the inlet of the second cooling bed. After hot rolling, the seamless steel pipe is transported to the first cooling bed for cooling using the first conveyor roller, and after being cooled on the first cooling bed, the seamless steel pipe is transported to the second cooling bed for cooling using the second conveyor roller.
[0008] Furthermore, the above-mentioned uniform cooling system for the hot-rolled seamless steel pipe also includes a collection frame, a first axial flow fan, and a second axial flow fan. The collection frame is located at the outlet of the second cooling bed, and the seamless steel pipe cooled by the second cooling bed enters the collection frame. The first axial flow fan is located outside the first conveyor roller, and the second axial flow fan is located outside the second cooling bed. Preferably, a temperature measuring gun is provided at the second conveyor roller.
[0009] Furthermore, in the aforementioned uniform cooling system for the hot-rolled seamless steel pipe, the first cooling bed and the second cooling bed are arranged side by side on a frame. Both the first cooling bed and the second cooling bed are bidirectional chain cooling beds. The bed body of the bidirectional chain cooling bed is composed of multiple forward chains and multiple reverse chains, which are alternately arranged. Each forward chain is driven by a forward chain drive motor, and each reverse chain is driven by a reverse chain drive motor. The forward direction of the forward chain is consistent with the movement direction of the seamless steel pipe, and the forward direction of the reverse chain is opposite to the movement direction of the seamless steel pipe. Each reverse chain is provided with a flat support plate, on which the seamless steel pipe is placed. Several columns are provided on the forward chain, which are evenly distributed along the length of the forward chain. The height of the forward chain is lower than that of the reverse chain. One end of each column is connected to the forward chain, and the other end of each column extends above the flat support plate.
[0010] Furthermore, in the above-mentioned uniform cooling system of the cooling bed after hot rolling of seamless steel pipe, multiple first axial flow fans are arranged sequentially at the inlet of the first cooling bed. The lower end of the first axial flow fan is connected to an angle adjustment motor, which can adjust the blowing angle of the first axial flow fan. The first axial flow fan blows air radially towards the seamless steel pipe.
[0011] Furthermore, in the aforementioned uniform cooling system of the cooling bed after hot rolling of seamless steel pipe, the first cooling bed is inclined, the height of the inlet of the first cooling bed is lower than the height of the outlet, and the inclination angle of the first cooling bed is 5°~20°; the distance L1 between the first axial flow fan and the inlet of the first cooling bed is 0.2m~1m; the distance h1 between the axis of the seamless steel pipe near the inlet of the first cooling bed and the ground is 0.5m~2m; and the distance h2 between the axis of the first axial flow fan and the ground is 0.5m~1.5m.
[0012] Furthermore, in the aforementioned uniform cooling system for the hot-rolled seamless steel pipe, the blowing angle of the first axial flow fan is adjusted according to the effective heat exchange area of the seamless steel pipe; the effective heat exchange area of the seamless steel pipe is calculated according to Formula 1:
[0013] F = Q / 0.9 * K * △tm (Formula 1)
[0014] In Formula 1, F is the effective heat exchange area, Q is the total heat exchange, K is the heat transfer coefficient, and Δtm is the average temperature difference.
[0015] The blowing angle of the first axial flow fan is calculated according to formula 2:
[0016] arctan[(h1-rr*sin6°-h2) / (r+r*sin6°+L1)] Formula 2
[0017] In Formula 2, h1 is the distance between the axis of the seamless steel pipe near the entrance of the first cooling bed and the ground, r is the radius of the seamless steel pipe, 6° is the tilt angle of the first cooling bed, and L1 is the distance between the first axial flow fan and the entrance of the first cooling bed.
[0018] Furthermore, in the aforementioned uniform cooling system of the cooling bed after hot rolling of seamless steel pipe, the operating frequency of the reverse chain is adjusted according to the effective heat exchange area of the seamless steel pipe; the operating frequency of the reverse chain is calculated according to Formula 3:
[0019] N = V / 100 = 2πrf (Formula 3)
[0020] In Formula 3, N is the operating frequency of the reverse chain, V is the linear velocity of the seamless steel pipe, r is the radius of the seamless steel pipe, and f is the frequency coefficient.
[0021] Furthermore, in the aforementioned uniform cooling system for the seamless steel pipe after hot rolling, the second cooling bed is horizontally arranged, and two sets of second axial flow fans are provided. Each set of second axial flow fans has multiple second axial flow fans. The second axial flow fans blow air axially toward the seamless steel pipe. The two sets of second axial flow fans are arranged opposite each other on both sides of the second cooling bed. One set of second axial flow fans is arranged from the inlet of the second cooling bed to the middle of the second cooling bed, and the other set of second axial flow fans is arranged from the outlet of the second cooling bed to the middle of the second cooling bed. The axis of the second axial flow fans is located on the same plane as the upper surface of the second cooling bed.
[0022] Furthermore, in the aforementioned uniform cooling system for the hot-rolled seamless steel pipe on the cooling bed, the second axial flow fan is mounted on a base, and a hydraulic lifting cylinder is located below the base. Sliding screws are located at both ends of the base, with one end connected to the base and the other end connected to the ground. The hydraulic lifting cylinder can drive the base to rise or fall, and this rise or fall can adjust the height of the second axial flow fan. By adjusting the height of the second axial flow fan, the axis of the second axial flow fan can be aligned with the axis of the seamless steel pipe on the second cooling bed.
[0023] Furthermore, in the above-mentioned uniform cooling system of the cooling bed after hot rolling of seamless steel pipe, when exiting the first cooling bed, the temperature difference of the entire length and batch of the seamless steel pipe is ≤50℃; when exiting the second cooling bed, the temperature difference between the inner and outer surfaces of the seamless steel pipe is ≤50℃, and the temperature of the seamless steel pipe at the end of the cooling process is ≤80℃; preferably, it also includes an infrared positioning device and a PLC program control component.
[0024] Analysis reveals that this invention discloses a uniform cooling system for seamless steel pipes after hot rolling. This system utilizes the heat exchange principle between the outer and inner surfaces of the seamless steel pipe and the characteristic that the outer surface of the seamless steel pipe dissipates heat quickly while the inner surface dissipates heat slowly. By setting a first axial flow fan that blows air radially onto the seamless steel pipe in the first cooling bed, the outer surface of the seamless steel pipe is uniformly cooled. By setting a second axial flow fan that blows air axially onto the seamless steel pipe in the second cooling bed, the inner surface of the seamless steel pipe is uniformly cooled. This achieves uniform cooling of the inner and outer surfaces of the seamless steel pipe after hot rolling, thereby maintaining the straightness of the seamless steel pipe, improving the product qualification rate of the seamless steel pipe, and greatly reducing the time and cost of subsequent process remediation. Attached Figure Description
[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:
[0026] Figure 1 This is a schematic diagram of a structure according to an embodiment of the present invention.
[0027] Figure 2 This is a schematic diagram of the structure of the first cooling bed and the first axial flow fan in one embodiment of the present invention.
[0028] Figure 3 This is a schematic diagram of the structure of the second cooling bed and the second axial flow fan in one embodiment of the present invention.
[0029] Figure 4 This is another structural schematic diagram of the first cooling bed and the first axial flow fan in one embodiment of the present invention.
[0030] Figure 5 This is another structural schematic diagram of the cooperation between the second cooling bed and the second axial flow fan according to an embodiment of the present invention.
[0031] Explanation of reference numerals in the attached drawings: 1 First conveyor roller; 2 Second conveyor roller; 3 First cooling bed; 4 Second cooling bed; 5 Seamless steel pipe; 6 Collection frame; 7 Forward chain; 8 Reverse chain; 9 Column; 10 First axial flow fan; 11 Second axial flow fan; 12 Angle adjustment motor; 13 Base; 14 Hydraulic lifting cylinder; 15 Sliding screw; 16 Frame. Detailed Implementation
[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. Indeed, those skilled in the art will recognize that modifications and variations can be made to the invention without departing from its scope or spirit. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the invention encompass such modifications and variations falling within the scope of the appended claims and their equivalents.
[0033] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected," "linked," and "set up" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a direct connection or an indirect connection through intermediate components; a wired connection, a radio connection, or a wireless communication signal connection. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.
[0034] The accompanying drawings illustrate one or more examples of the invention. The detailed description uses numerals and letters to refer to features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to refer to similar or analogous parts of the invention. As used herein, the terms “first,” “second,” and “third,” etc., are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.
[0035] like Figures 1 to 5 As shown, according to an embodiment of the present invention, a uniform cooling bed system for hot-rolled seamless steel pipes is provided, such as... Figure 1As shown, the cooling system includes a first conveyor roller 1, a second conveyor roller 2, a first cooling bed 3, and a second cooling bed 4. The first conveyor roller 1 is connected to the inlet of the first cooling bed 3, and the second conveyor roller 2 is connected to both the outlet of the first cooling bed 3 and the inlet of the second cooling bed 4. The seamless steel pipe 5 after hot rolling is transported to the first cooling bed 3 for cooling using the first conveyor roller 1. After being cooled by the first cooling bed 3, the seamless steel pipe 5 is transported to the second cooling bed 4 for cooling using the second conveyor roller 2.
[0036] Furthermore, it also includes a collection frame 6, a first axial flow fan 10, and a second axial flow fan 11. The collection frame 6 is located at the outlet of the second cooling bed 4. The seamless steel pipe 5, after being cooled by the second cooling bed 4, enters the collection frame 6. The first axial flow fan 10 is located outside the first conveyor roller 1, and the second axial flow fan 11 is located outside the second cooling bed 4. A temperature measuring gun is installed at the second conveyor roller 2, which is used to measure the lower temperature of the seamless steel pipe 5 on the first cooling bed 3.
[0037] Furthermore, the first cooling bed 3 and the second cooling bed 4 are arranged side by side on the frame 16. Both the first cooling bed 3 and the second cooling bed 4 are bidirectional chain cooling beds. The bed body of the bidirectional chain cooling bed is composed of multiple forward chains 7 and multiple reverse chains 8, which are arranged alternately. The multiple forward chains 7 are driven by forward chain drive motors, and the multiple reverse chains 8 are driven by reverse chain drive motors. The forward direction of the forward chain 7 is the same as the movement direction of the seamless steel pipe 5, and the forward direction of the reverse chain 8 is opposite to the movement direction of the seamless steel pipe 5. Each reverse chain 8 is equipped with a flat support plate, on which the seamless steel pipe 5 is placed. On the pallet, several columns 9 are set on the forward chain 7. The columns 9 are evenly distributed along the length of the forward chain 7. The height of the forward chain 7 is lower than that of the reverse chain 8. One end of the column 9 is connected to the forward chain 7, and the other end of the column 9 extends to the top of the flat pallet. When the reverse chain drive motor runs, the reverse chain 8 drives the flat pallet to move synchronously. The movement of the flat pallet causes the seamless steel pipe 5 to rotate at the column 9. The forward chain 7 pushes the seamless steel pipe 5 to move through the column 9. The seamless steel pipe 5 rolls forward under the combined action of the forward chain 7 and the reverse chain 8. By intermittently starting and stopping the forward chain 7, the seamless steel pipe 5 can advance one or more material positions each time.
[0038] Furthermore, multiple first axial flow fans 10 are arranged sequentially at the inlet of the first cooling bed 3, such as... Figure 2As shown, an angle-adjusting motor 12 is connected to the lower end of the first axial flow fan 10. The angle-adjusting motor 12 can adjust the blowing angle of the first axial flow fan 10, which blows air radially towards the seamless steel pipe 5. The first axial flow fan 10 blows air onto the surface of the seamless steel pipe 5, and the angle-adjusting motor 12 adjusts the blowing angle of the axial flow fan to ensure that the surface cooling area of the seamless steel pipe 5 is maximized. The hot-rolled seamless steel pipe 5 is conveyed to the first cooling bed 3 by the first conveyor roller 1. The first cooling bed 3 is a climbing cooling bed. At the entrance of the first cooling bed 3, a certain number of first axial flow fans 10 are added and connected to the angle adjustment motor 12. According to the different diameters of the seamless steel pipe 5, the blowing angle of the first axial flow fan 10 is adjusted so that the original blowing surface of the first axial flow fan 10 is perpendicular to the radial direction of the seamless pipe. Then, the angle is finely adjusted according to the lower temperature of the seamless steel pipe 5 in the first cooling bed 3 to ensure that the surface of the seamless steel pipe 5 is cooled to the maximum uniformity and improve the surface cooling efficiency of the seamless steel pipe 5.
[0039] Furthermore, such as Figure 4 As shown, the first cooling bed 3 is inclined, with the height of the inlet of the first cooling bed 3 being lower than the height of the outlet. The inclination angle α of the first cooling bed 3 is 5°~20°. This setting can prevent seamless steel pipes 5 with different outer diameters and different curvatures from shaking at the material level due to the operation of the reverse chain 8, and avoid the seamless steel pipes 5 from being misaligned in the first cooling bed 3. The distance L1 between the first axial flow fan 10 and the inlet of the first cooling bed 3 is 0.2m~1m. The distance h1 between the axis of the seamless steel pipe 5 near the inlet of the first cooling bed 3 and the ground is 0.5m~2m. The distance h2 between the axis of the first axial flow fan 10 and the ground is 0.5m~1.5m.
[0040] Furthermore, the blowing angle of the first axial flow fan 10 is adjusted according to the effective heat exchange area of the seamless steel pipe 5; the effective heat exchange area of the seamless steel pipe 5 is calculated according to Formula 1:
[0041] F = Q / 0.9 * K * △tm (Formula 1)
[0042] In Formula 1, F is the effective heat exchange area, Q is the total heat exchange, K is the heat transfer coefficient, Δtm is the average temperature difference, and 0.9 is the adjustment compensation value.
[0043] The blowing angle of the first axial flow fan 10 is calculated according to formula 2:
[0044] arctan[(h1-rr*sin6°-h2) / (r+r*sin6°+L1)] Formula 2
[0045] In Formula 2, h1 is the distance between the axis of the seamless steel pipe 5 near the entrance of the first cooling bed 3 and the ground, r is the radius of the seamless steel pipe 5, 6° is the tilt angle of the first cooling bed 3, and L1 is the distance between the axis of the first axial fan 10 and the entrance of the first cooling bed 3.
[0046] Furthermore, the operating frequency of the reverse chain 8 is adjusted according to the effective heat exchange area of the seamless steel pipe 5; the operating frequency of the reverse chain 8 is calculated according to formula 3:
[0047] N = V / 100 = 2πrf (Formula 3)
[0048] In Formula 3, N is the operating frequency of the reverse chain 8, V is the linear velocity of the seamless steel pipe 5, r is the radius of the seamless steel pipe 5, and f is the frequency coefficient (the frequency coefficient f is calculated as 1).
[0049] Preferably, the specific operating speed of the reverse chain 8 is adjusted according to the outer diameter of the steel. When the outer diameter of the seamless steel pipe 5 is <150mm, the frequency of the reverse chain 8 is 3Hz, and when the outer diameter of the seamless steel pipe 5 is ≥150mm, the frequency of the reverse chain 8 is 5Hz.
[0050] After calculating the effective heat exchange area of the seamless steel pipe 5 according to Formula 1, the blowing angle of the first axial flow fan 10 is calculated according to Formula 2, and the operating frequency of the reverse chain 8 is calculated according to Formula 3. The blowing angle of the first axial flow fan 10 is adjusted by the angle-adjusting motor 12. After the angle of the angle-adjusting motor 12 is fixed, the operating frequency of the reverse chain 8 is adjusted. The operating speed of the reverse chain 8 is adjusted according to the size of the seamless steel pipe 5, such as the outer diameter, so that the surface of the seamless steel pipe 5 is maximized by radial wind force, thereby controlling uniform cooling heat exchange and ensuring that the outer surface of the seamless steel pipe 5 can achieve uniform and controllable cooling speed on the first cooling bed 3.
[0051] Furthermore, such as Figure 3 As shown, the second cooling bed 4 is horizontally arranged, and there are two sets of second axial flow fans 11. Each set of second axial flow fans 11 has multiple second axial flow fans 11. The second axial flow fans 11 blow air axially towards the seamless steel pipe 5. The two sets of second axial flow fans 11 are arranged opposite each other on both sides of the second cooling bed 4. One set of second axial flow fans 11 is arranged from the inlet of the second cooling bed 4 to the middle of the second cooling bed 4, and the other set of second axial flow fans 11 is arranged from the outlet of the second cooling bed 4 to the middle of the second cooling bed 4. The axis of the second axial flow fans 11 is located on the same plane as the upper surface of the second cooling bed 4.
[0052] Furthermore, such as Figure 3As shown, each group of second axial flow fans 11 is mounted on a base 13. A hydraulic lifting cylinder 14 is located below the base 13. Sliding screws 15 are located at both ends of the base 13; one end of each screw is connected to the base 13, and the other end is connected to the ground. The hydraulic lifting cylinder 14 can drive the base 13 to rise or fall, and this rising or falling of the base 13 can adjust the height of the second axial flow fan 11. Figure 5 As shown, by adjusting the height of the second axial flow fan 11, the axis of the second axial flow fan 11 can be made to lie on the same plane as the axis of the seamless steel pipe 5 on the second cooling bed 4. By setting the same number of second axial flow fans 11 on both sides of the second cooling bed 4, and cooperating with the hydraulic lifting cylinder 14, the second axial flow fans 11 can be moved up and down, ensuring that the inner surface of seamless steel pipes 5 of different diameters can be uniformly cooled.
[0053] Furthermore, when the seamless steel pipe 5 exits the first cooling bed 3, the temperature difference along the entire length of the seamless steel pipe 5 and the batch temperature difference are ≤50℃ (the temperature difference between the two ends of the seamless steel pipe 5 of the same specification and steel grade is ≤50℃); when the seamless steel pipe 5 exits the second cooling bed 4, the temperature difference between the inner and outer surfaces of the seamless steel pipe 5 is ≤50℃, and the temperature of the seamless steel pipe 5 at the end of the cooling line is ≤80℃.
[0054] After the seamless steel pipe 5 is cooled to a certain temperature by the first cooling bed 3, it is transferred to the second cooling bed 4 by the second conveyor roller 2. Before entering the second cooling bed 4, the surface temperature of the seamless steel pipe 5 is detected by a temperature measuring gun at the second conveyor roller 2. Based on the average surface temperature data, the elevation angle of the first axial flow fan 10 is slightly adjusted (≤5°) to ensure that the temperature difference of the entire length and batch of the seamless steel pipe 5 is ≤50° when it is placed on the first cooling bed 3. Then, the pipe is placed on the second cooling bed 4 by the turning hook. The original positions of the second axial flow fans 11 on both sides of the second cooling bed 4 are parallel and in contact with the second cooling bed 4. Based on the outer diameter D of the seamless steel pipe 5 on the second cooling bed 4, the optimal angle for uniform cooling of the inner surface of the seamless steel pipe 5 is calculated. The second axial flow fan 11 lifts the base 1 through the hydraulic lifting cylinder 14. 3. The base 13 is raised to half the outer diameter D of the seamless steel pipe 5, aligning the center of the second axial flow fan 11 with the axis of the seamless steel pipe 5. This ensures that the inner wall of the seamless steel pipe 5 maintains a uniform cooling rate. The heat exchange area of the inner surface of the seamless steel pipe 5 can be calculated using the formula F=Q / 0.8*K*△tm (since the heat dissipation area of the inner wall of the seamless steel pipe 5 is small, the heat exchange coefficient is reduced from 0.9 in formula 1 to 0.8). This achieves uniform cooling of the inner surface of the seamless steel pipe 5. By adjusting the forward chain speed, it is ensured that the temperature difference between the inner and outer surfaces of the seamless steel pipe 5 is ≤50℃ when it is taken off the second cooling bed 4. This also controls the overall temperature of the hot-rolled seamless steel pipe 5 when it is taken off the line, ensuring that the temperature is ≤80℃.
[0055] This system utilizes the heat exchange principle between the outer and inner surfaces of the seamless steel pipe 5, and the characteristic that the outer surface of the seamless steel pipe 5 dissipates heat quickly while the inner surface dissipates heat slowly. The first cooling bed 3 is designed as a climbing cooling bed, which facilitates a smooth heat exchange process on the outer surface of the seamless steel pipe 5. Simultaneously, the second cooling bed 4 is designed as a horizontal structure, allowing the inner circle of the seamless steel pipe 5 to form a concentric circle with the second axial flow fan 11, facilitating uniform cooling of the inner surface of the seamless steel pipe 5. The combination of the first cooling bed 3 and the second cooling bed 4 achieves uniform cooling of the seamless steel pipe 5 after hot rolling, thereby maintaining the straightness of the seamless steel pipe 5, improving the product qualification rate of the seamless steel pipe 5, and significantly reducing the time and cost of subsequent rework.
[0056] Furthermore, the system also includes an infrared locator and a PLC program control component. The infrared locator is a high-temperature monitoring device with an infrared illumination reference finding function. The infrared locator is set in the middle of the second cooling bed 4 to monitor the temperature of the seamless steel pipe 5 on the second cooling bed 4. The PLC program control component adjusts the angle of the second axial flow fan 11 according to the temperature detected by the infrared locator, following the principle of lower angle for higher temperatures and higher angle for lower temperatures.
[0057] The following is a comparative test of cooling the hot-rolled seamless steel pipe 5 (wall thickness S≤30) and thick-walled (S≥50) seamless steel pipes using the cooling system of this invention and the existing technology (fixed fan blowing cold air along the axis of the seamless pipe to cool the seamless steel pipe) for cooling:
[0058] Table 1: Material Selection
[0059]
[0060] Table 2: Performance Comparison of Cooling for Thin-Walled Tubes with 16MnA Billet Grade Using the Invention and Existing Technologies
[0061]
[0062] Table 3: Comparison of the bending degree of thin-walled tubes with billet grade 16MnA cooled using the present invention and existing technologies.
[0063]
[0064] Table 4: Performance comparison of cooling for thick-walled tubes of billet grade 45 using the present invention and existing technologies.
[0065]
[0066] Table 5: Comparison of the bending degree of thick-walled tubes with billet grade 45 cooled using the present invention and existing technologies respectively.
[0067]
[0068] Two representative specifications with different wall thicknesses after hot rolling (16MnA composition specification 108×16; 45 composition specification 194×50) were produced using the cooling bed operation mode of this invention and existing technologies. The full-length cross-sectional performance of the two groups of hot-rolled seamless steel pipes was compared, along with the overall curvature. The comprehensive performance parameters and curvature comparisons are shown in Tables 2, 3, 4, and 5. It can be seen that the comprehensive parameters and performance uniformity of the hot-rolled seamless steel pipes produced using this invention are superior to those produced using existing technologies.
[0069] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:
[0070] A uniform cooling system for hot-rolled seamless steel pipes is disclosed. This system utilizes the heat exchange principle between the outer and inner surfaces of the seamless steel pipe 5, as well as the characteristic that the outer surface of the seamless steel pipe 5 dissipates heat quickly while the inner surface dissipates heat slowly. By setting a first axial flow fan 10 in the first cooling bed 3 to blow air radially onto the seamless steel pipe 5, the outer surface of the seamless steel pipe 5 is uniformly cooled. By setting a second axial flow fan 11 in the second cooling bed 4 to blow air axially onto the seamless steel pipe 5, the inner surface of the seamless steel pipe 5 is uniformly cooled. This achieves uniform cooling of the inner and outer surfaces of the seamless steel pipe 5 after hot rolling, thereby maintaining the straightness of the seamless steel pipe 5, improving the product qualification rate of the seamless steel pipe 5, and greatly reducing the time and cost of subsequent process remediation.
[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A uniform cooling bed system for hot-rolled seamless steel pipes, characterized in that, It includes a first conveyor roller, a second conveyor roller, a first cooling bed, and a second cooling bed, wherein, The first conveyor roller is connected to the inlet of the first cooling bed. The second conveyor roller is connected to both the outlet of the first cooling bed and the inlet of the second cooling bed. After hot rolling, the seamless steel pipe is transported to the first cooling bed by the first conveyor roller for cooling. After cooling on the first cooling bed, the seamless steel pipe is transported to the second cooling bed by the second conveyor roller for cooling. It also includes a collection frame, a first axial flow fan, and a second axial flow fan. The collection frame is located at the outlet of the second cooling bed, and the seamless steel pipe, after being cooled by the second cooling bed, enters the collection frame. The first axial flow fan is located outside the first conveyor roller, and the second axial flow fan is located outside the second cooling bed. Multiple first axial flow fans are arranged sequentially at the inlet of the first cooling bed. The lower end of each first axial flow fan is connected to an angle adjustment motor, which can adjust the blowing angle of the first axial flow fan. The first axial flow fan blows air radially toward the seamless steel pipe. The second cooling bed is horizontally positioned, and two sets of the second axial flow fans are provided, with each set containing multiple second axial flow fans. The second axial flow fan blows air axially onto the seamless steel pipe. Two sets of the second axial flow fans are arranged opposite each other on both sides of the second cooling bed; One set of second axial flow fans is arranged from the inlet of the second cooling bed to the middle of the second cooling bed, and another set of second axial flow fans is arranged from the outlet of the second cooling bed to the middle of the second cooling bed; The axis of the second axial flow fan is located in the same plane as the upper surface of the second cooling bed. The second axial flow fan is mounted on a base, and a hydraulic lifting cylinder is located below the base. Sliding screws are located at both ends of the base, with one end of the sliding screw connected to the base and the other end connected to the ground. The hydraulic lifting cylinder can drive the base to rise or fall, and the rising or falling of the base can adjust the height of the second axial flow fan. By adjusting the height of the second axial flow fan, the axis of the second axial flow fan can be made to lie on the same plane as the axis of the seamless steel pipe on the second cooling bed.
2. The uniform cooling system for seamless steel pipes after hot rolling on a cooling bed according to claim 1, characterized in that, A temperature measuring gun is installed at the second conveyor roller.
3. The uniform cooling system for seamless steel pipes after hot rolling on a cooling bed according to claim 1, characterized in that, The first cooling bed and the second cooling bed are arranged side by side on the frame. Both the first cooling bed and the second cooling bed are bidirectional chain cooling beds. The bed body of the bidirectional chain cooling bed is composed of multiple forward chains and multiple reverse chains. The multiple forward chains and multiple reverse chains are arranged alternately. The multiple forward chains are driven by forward chain drive motors, and the multiple reverse chains are driven by reverse chain drive motors. The forward direction of the forward chain is the same as the movement direction of the seamless steel pipe, and the forward direction of the reverse chain is opposite to the movement direction of the seamless steel pipe. Each of the reverse chains is provided with a flat support plate, on which the seamless steel pipe is placed. Several columns are provided on the forward chain, which are evenly distributed along the length of the forward chain. The height of the forward chain is lower than that of the reverse chain. One end of the column is connected to the forward chain, and the other end of the column extends above the flat support plate.
4. The uniform cooling system for the hot-rolled seamless steel pipe cooling bed according to claim 1, characterized in that, The first cooling bed is tilted, with the height of the inlet of the first cooling bed being lower than the height of the outlet, and the tilt angle of the first cooling bed is 5°~20°; The distance L1 between the first axial flow fan and the inlet of the first cooling bed is 0.2m to 1m; The distance h1 between the axis of the seamless steel pipe near the entrance of the first cooling bed and the ground is 0.5m to 2m; The distance h2 between the axis of the first axial flow fan and the ground is 0.5m to 1.5m.
5. The uniform cooling system for seamless steel pipes after hot rolling on a cooling bed according to claim 1, characterized in that, When the seamless steel pipe leaves the first cooling bed, the temperature difference along its entire length and in batches is ≤50℃. When the seamless steel pipe exits the second cooling bed, the temperature difference between the inner and outer surfaces is ≤50℃, and the temperature at which the seamless steel pipe exits the cooling bed is ≤80℃.
6. The uniform cooling system for the hot-rolled seamless steel pipe cooling bed according to claim 1, characterized in that, It also includes an infrared locator and a PLC program control component.