A cold bending steel pipe heat treatment device and heat treatment method

Abstract

The application discloses a cold-bending steel pipe heat treatment device and heat treatment method, relates to the technical field of cold-bending steel pipe heat treatment, and comprises a treatment tank, symmetrically fixed supports are arranged at the bottom of the treatment tank, an inlet for the cold-bending steel pipe to pass through is arranged at the upper end of the treatment tank, a cover plate is slidably connected to the inlet, the cover plate penetrates through one side of the inlet and is slidably connected with the inlet, a pull ring is fixedly connected to the end of the cover plate extending out of the inlet, the motor is started, the output shaft of the motor slowly rotates with the rotating drum, the partition fan fixedly connected to the outer side of the rotating drum slowly rotates, the steel pipe can be directly conveyed to the inlet through conveying equipment after cold-bending treatment, then directly enters the treatment tank through the inlet to be heat treated, heat treatment can be immediately carried out after one steel pipe is cold-bended, and heat treatment does not need to be carried out after a batch of steel pipes are cold-bended, so that the quality of the cold-bending and heat treatment of the steel pipe can be ensured.

Description

Technical Field

[0001] This invention relates to the field of heat treatment technology for cold-formed steel pipes, specifically to a heat treatment apparatus and method for cold-formed steel pipes. Background Technology

[0002] Cold-formed steel pipes, as an important pipe component, are widely used in various industries such as construction, machinery manufacturing, pipeline transportation, and steel structures. After cold bending, residual stress is generated inside, and the metallographic structure of the pipe will be distorted. If standardized heat treatment is not carried out in time, it is easy to cause problems such as deformation, cracking, and reduced corrosion resistance during subsequent use of the steel pipe. Therefore, the heat treatment process after cold bending is a key link to ensure the quality and performance of cold-formed steel pipe products.

[0003] In existing technologies, the heat treatment of cold-formed steel pipes often adopts a batch-based centralized processing mode. This means that after processing a batch of cold-formed steel pipes, they are all transported to heat treatment equipment for heating, holding, and cooling. This method has significant technical drawbacks: Firstly, there is a time interval between the completion of cold-formed steel pipe processing and the start of heat treatment, allowing residual stress to relax and redistribute locally. This can lead to insufficient repair of the pipe's metallographic structure, making it difficult to guarantee the stress relief effect after heat treatment and affecting the dimensional accuracy and structural strength of the steel pipe. Secondly, during batch processing, a large number of cold-formed steel pipes are stacked into the heat treatment tank, which can easily cause the pipes to stick together and become clogged. This results in uneven heating of the pipes, with some areas failing to reach the optimal heat treatment temperature, while other areas experience overheating and coarsening of the microstructure, significantly reducing the overall quality of the heat treatment.

[0004] Therefore, the present invention proposes a heat treatment device and heat treatment method for cold-bent steel pipes. Summary of the Invention

[0005] The purpose of this invention is to provide a heat treatment apparatus and method for cold-bent steel pipes to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a heat treatment device for cold-bent steel pipes, comprising a treatment tank, wherein supports are symmetrically and fixedly connected to the bottom of the treatment tank, and an inlet for the passage of cold-bent steel pipes is provided at the upper end of the treatment tank, a cover plate is slidably connected to the inlet, and the cover plate extends through and is slidably connected to the inlet, a pull ring is fixedly connected to one end of the cover plate extending through the inlet, an integrated control console is fixedly connected to the upper end of one side of the treatment tank, and a heating element is provided inside the treatment tank; Preferably, a rotating drum extends through and rotatably connects to the processing tank. A motor is fixedly connected to one end of the rotating drum extending through the processing tank. The motor is electrically connected to the integrated control console. Multiple partition fans are fixedly connected in a ring at equal intervals on the outer wall of the rotating drum. A temperature sensor is embedded and fixedly installed in the inner wall of the processing tank. The temperature sensor is electrically connected to the integrated control console. The partition fans are made of 310S stainless steel.

[0007] Preferably, the heating element includes a heating tube, which is sleeved inside the rotating drum. One end of the heating tube extending out of the rotating drum passes through the processing tank and is fixedly connected to the processing tank. The inner wall of the heating tube has multiple air outlets arranged in a ring at equal intervals. Each air outlet is adjacent to a heater, which is ring-shaped and fixedly connected to the side wall of the heating tube. The multiple heaters are electrically connected to each other by heat-insulating wires. The heaters are electrically connected to an integrated control console. Each partition has multiple heating chambers arranged at equal intervals, and each partition has a U-shaped channel connected to the heating chambers.

[0008] Preferably, heat outlet holes are densely arranged on the side walls of both the heating chamber and the U-shaped channel.

[0009] Preferably, an inverted conical ring is fixedly connected to the outer wall of the rotating drum, and the slope of the inverted conical ring is inclined towards the center of the rotating drum with the direction away from the motor as a reference. A bucket is detachably connected to the upper end of the processing tank near the integrated control console.

[0010] Preferably, each of the air outlets is fixedly connected to an air guide ring inside the heating tube, and the diameter of the hollow ring opening inside the multiple air guide rings decreases sequentially with respect to the direction away from the motor.

[0011] Preferably, the rotating drum has a turning hole on the side near the motor, and the processing tank has an air outlet channel. The turning hole is used to connect the air outlet channel and the heating pipe, and a sealing block is detachably connected to the bottom of the air outlet channel.

[0012] Preferably, the processing tank has an irregularly shaped cavity, the lower end of which is connected to the air outlet channel, and an air inlet is provided on the side wall between the irregularly shaped cavity and the inlet.

[0013] Preferably, slides are provided on both sides of the entrance, and guide rails are fixedly connected to both sides of the cover plate. The guide rails extend through the slides and are slidably connected to the slides.

[0014] Preferably, a heat treatment method for cold-bent steel pipes is a method of using a heat treatment device for cold-bent steel pipes.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention involves connecting the end of the heating tube furthest from the motor to the fan duct during heat treatment of cold-bent steel pipes. The buttons on the integrated control panel are adjusted to put the treatment tank into heat treatment mode. In heat treatment mode, the heater starts, emitting heat that enters the heating chamber through the air outlet and then into the treatment tank through the heat outlet hole. The temperature inside the treatment tank gradually rises, and the temperature sensor detects the temperature in real time and transmits it to the display screen of the integrated control panel. This means that the optimal heat treatment temperature can be adjusted in a timely manner according to the different models of cold-bent steel pipes required, facilitating better heat treatment results. Once the temperature inside the treatment tank reaches the specified temperature, the cover plate is moved a corresponding distance by pulling the pull ring according to the size of the cold-bent steel pipe being placed inside, matching the size of the exposed inlet to the size of the cold-bent steel pipe. In other words, the inlet size can be adjusted according to the size of the cold-bent steel pipe to be heat-treated, effectively reducing heat loss inside the treatment tank, promoting energy conservation, maintaining thermal balance inside the treatment tank, and thus ensuring the quality of heat treatment of the cold-bent steel pipes. 2. This invention starts a motor, and the output shaft of the motor drives the drum to rotate slowly. The partition fan fixedly connected to the outside of the drum rotates slowly. After the steel pipe is cold-bent, it can be directly transported to the inlet by the conveying equipment, and then directly enter the processing tank for heat treatment. It can perform heat treatment immediately after cold bending a steel pipe, instead of waiting for a batch of cold-bent steel pipes to be heat-treated in a concentrated manner, which can ensure the quality of cold bending and heat treatment of steel pipes. 3. This invention divides the space inside the processing tank into several rotatable and movable spaces using partitioned fans. When a cold-bent steel pipe falls into the processing tank, it will fall into one of the spaces partitioned by the fans. As the fans rotate, they carry the cold-bent steel pipe away from this space. Under the action of the inverted conical ring, the cold-bent steel pipe slides downwards due to its own weight, eventually falling to the other side of the processing tank. Then, the next cold-bent steel pipe will fall into the space partitioned by the fans, and so on. This process prevents the cold-bent steel pipes from accumulating and blocking the entrance of the processing tank; it also prevents large collisions between the cold-bent steel pipes, thus preventing stress damage; and it can automatically transport the cold-bent steel pipes to places inside the processing tank that cannot be directly accessed, thereby saving space and making it practical and efficient. 4. The present invention, through the design of the partition fan made of 310S stainless steel, can facilitate the conduction of heat and facilitate better heat treatment of cold-bent steel pipes. 5. The present invention uses multiple heaters connected in series with insulated wires to effectively and quickly dissipate heat. Each heater is provided with an air outlet, which can more efficiently send heat into the heating chamber through the air outlet. 6. The present invention uses a fan to slowly blow air into the heating tube. The airflow moves inside the heating tube and, under the action of the air guide ring, carries heat through the air outlet and sends it into the heating chamber, so as to facilitate rapid heat transfer to the partition fan. 7. The present invention, through the design of the loop channel, can connect multiple heating chambers, thereby making the heat in the multiple heating chambers more uniform. The loop channel itself can also promote the rapid heat transfer of the partition fan, so that the cold-bent steel pipes in each section of the partition fan are heated to the same degree, and all of them are at the optimal heat treatment temperature of this type of cold-bent steel pipe. 8. The present invention, through the design of the heat outlet hole, can slowly dissipate the hot air through the heat outlet hole under the action of the airflow sent by the fan, which can ensure that there is always appropriate heat in the treatment tank, and can carry the heat to the cold pipe steel pipe cylinder position that rotates with the partition fan, which can further promote the heat treatment effect of cold-bent steel pipe, making it more practical and efficient. 9. This invention uses a design where the diameter of the hollow openings inside multiple air guide rings decreases sequentially with respect to the direction away from the motor. This means that as the airflow moves into the heating tube, the diameter of the openings inside the heating tube decreases sequentially along the direction of the airflow. In other words, the area of ​​the air guide rings inside the heating tube increases as the airflow moves along the direction of the airflow. As the airflow flows inside the heating tube, the air guide rings sequentially intercept the same portion of the airflow, carrying heat through the air outlet into the heating chamber, which can promote thermal balance in each area of ​​the partition fan. 10. By removing the sealing block, the airflow flows inside the heating tube and is sequentially intercepted by multiple air guide rings. The remaining small amount of airflow carrying heat will enter the air outlet channel through the turning hole and flow downwards, eventually flowing downwards out of the air outlet channel. This guides the airflow carrying heat to the bottom of the device, preventing burns to nearby staff and making it safer. 11. After heat treatment, the cold-bent steel pipe needs to be cooled to ensure sufficient microstructure transformation and eliminate secondary stress. At this time, the treatment tank is adjusted to the post-heat treatment cooling mode by controlling the buttons on the integrated control console. In the post-heat treatment cooling mode, the motor starts normally, the air outlet is closed by the sealing block, the heater is turned off and not started, and the inlet can be opened to a greater distance by pulling the pull ring as needed to accelerate heat dissipation. The fan forces air into the heating pipe, and the strong airflow is sent into the heating chamber and the return channel through the air guide ring and then sprayed out through the heat outlet hole, thereby forcibly cooling the heat-treated cold-bent steel pipe as the partition fan rotates. The cooling effect is determined by controlling the wind force of the airflow sent by the fan. Attached Figure Description

[0016] Figure 1 This is an overall structural diagram of the present invention; Figure 2 This is an overall sectional view of the present invention; Figure 3 This is a partial cross-sectional view of the present invention; Figure 4 This is an overall bottom view of the present invention; Figure 5 This is a view of the external shape of the inverted conical ring of the present invention; Figure 6 This is an external view of the heating element of the present invention; Figure 7 This is a cross-sectional view of the heating element of the present invention; Figure 8 For the present invention Figure 2 A magnified view of a section at point A in the middle; Figure 9 For the present invention Figure 1 A magnified view of a section at point B.

[0017] In the picture: 1. Processing tank; 11. Support; 12. Inlet; 13. Cover plate; 14. Pull ring; 15. Integrated control console; 2. Motor; 21. Rotary drum; 22. Zoned fan; 23. Temperature sensor; 3. Heating tube; 31. Air outlet; 32. Heater; 33. Insulated wire; 34. Heating chamber; 35. U-shaped channel; 4. Heat outlet hole; 5. Inverted cone ring; 51. Inverted bucket; 6. Air guide ring; 7. Turning hole; 71. Air outlet channel; 72. Sealing block; 8. Irregular cavity; 81. Air inlet; 9. Guide rail; 91. Slide rail. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1 to 9 The present invention provides a technical solution: A heat treatment device for cold-bent steel pipes includes a treatment tank 1. A support 11 is symmetrically fixedly connected to the bottom of the treatment tank 1. An inlet 12 for the cold-bent steel pipe to pass through is opened at the upper end of the treatment tank 1. A cover plate 13 is slidably connected to the inlet 12, and the cover plate 13 extends through and extends out of the inlet 12 and is slidably connected to the inlet 12. A pull ring 14 is fixedly connected to one end of the cover plate 13 extending out of the inlet 12. An integrated control console 15 is fixedly connected to the upper end of one side of the treatment tank 1. A heating element is provided inside the treatment tank 1.

[0020] As an embodiment of the present invention, as shown in the figure, a rotating cylinder 21 extends through and is rotatably connected to the processing tank 1. A motor 2 is fixedly connected to one end of the rotating cylinder 21 extending through the processing tank 1. The motor 2 is electrically connected to the integrated control console 15. Multiple partition fans 22 are fixedly connected in a ring at equal intervals on the outer wall of the rotating cylinder 21. A temperature sensor 23 is embedded and fixedly installed in the inner wall of the processing tank 1. The temperature sensor 23 is electrically connected to the integrated control console 15. The partition fans 22 are made of 310S stainless steel. The partition fan 22 divides the space inside the processing tank 1 into several rotatable and movable spaces. When a cold-bent steel pipe falls into the processing tank 1, it will fall into one of the spaces divided by the partition fan 22. Then, as the partition fan 22 rotates, it will carry the cold-bent steel pipe away from that space. Under the action of the inverted cone ring 5, the cold-bent steel pipe will slide downwards due to its own gravity and eventually fall to the other side of the processing tank 1. Then, the next cold-bent steel pipe will fall into the space divided by the partition fan 22, and so on. This can prevent the cold-bent steel pipes from being concentrated and blocked at the entrance 12 of the processing tank 1 when they fall into the processing tank 1; it can also prevent large collisions between the cold-bent steel pipes, thereby preventing stress damage to the cold-bent steel pipes; and it can automatically transport the cold-bent steel pipes to places inside the processing tank 1 that the cold-bent steel pipes cannot fall into, thus saving space and being practical and efficient. The partition fan 22 is made of 310S stainless steel (06Cr25Ni20Si2), which facilitates heat conduction and allows for better heat treatment of cold-bent steel pipes. The thermal conductivity of 310S stainless steel increases with temperature (reaching 21.5 W / (m・K) at 500℃), complementing the heat transfer of the hot air in the heating chamber 34. This allows for rapid heat transfer from the chamber to the fan surface, achieving contact heat transfer with the cold-bent steel pipe and improving heat treatment efficiency. 310S stainless steel can also operate stably at temperatures below 800℃ for extended periods, fully covering the heat treatment temperature requirements of the cold-bent steel pipe, and exhibits no significant thermal deformation during temperature cycling. As an austenitic chromium-nickel stainless steel, the austenitic structure provides excellent impact resistance, allowing it to withstand minor impacts from the cold-bent steel pipe. Furthermore, a dense chromium oxide protective film easily forms on the surface, providing oxidation and corrosion resistance and preventing oxide scale from falling off and contaminating the cold-bent steel pipe. Compared to nickel-based alloys, 310S stainless steel is more cost-effective, meeting the industrial production needs of cold-bent steel pipes. It also has good machinability, allowing for precise fabrication of the heating chamber 34, the U-shaped channel 35, and the heat outlet hole 4.

[0021] During operation, motor 2 is started, and the output shaft of motor 2 drives the rotating drum 21 to rotate slowly. The partition fan 22 fixedly connected to the outside of the rotating drum 21 rotates slowly. After the steel pipe is cold-bent, it can be directly transported to the inlet 12 through the conveying equipment, and then directly enter the processing tank 1 through the inlet 12 for heat treatment. Heat treatment can be carried out immediately after cold bending a steel pipe, instead of waiting for a batch to be cold-bent and then carrying out heat treatment in a concentrated manner, which can ensure the quality of cold bending and heat treatment of steel pipes.

[0022] As an embodiment of the present invention, as shown in the figure, the heating element includes a heating tube 3, which is sleeved inside a rotating cylinder 21. One end of the heating tube 3 extends out of the rotating cylinder 21 and passes through the processing tank 1 and is fixedly connected to the processing tank 1. The inner wall of the heating tube 3 has multiple air outlets 31 arranged in an annular pattern at equal intervals. Each air outlet 31 is adjacent to a heater 32. The heater 32 is annular and fixedly connected to the side wall of the heating tube 3. The multiple heaters 32 are electrically connected to each other by heat-insulating wires 33. The heaters 32 are electrically connected to an integrated control console 15. Each partition fan 22 has multiple heating chambers 34 arranged at equal intervals, and each partition fan 22 has a loop-shaped channel 35 connected to the heating chambers 34.

[0023] During operation, multiple heaters 32 are connected in series through insulated wires 33, which can effectively and quickly dissipate heat. Each heater 32 is provided with an air outlet 31, which can more efficiently send heat into the heating chamber 34 through the air outlet 31. When the fan is working, it slowly blows air into the heating tube 3. The airflow moves inside the heating tube 3 and, under the action of the air guide ring 6, carries the heat through the air outlet 31 and sends it into the heating chamber 34 so as to facilitate rapid heat transfer to the partition fan 22. The design of the U-shaped channel 35 can connect multiple heating chambers 34, thereby making the heat in the multiple heating chambers 34 more uniform. The U-shaped channel 35 itself can also promote the rapid heat transfer of the partition fan 22, so that the cold-bent steel pipes in each section of the partition fan 22 are heated to the same degree, and all of them are at the optimal heat treatment temperature of this type of cold-bent steel pipe.

[0024] As an embodiment of the present invention, as shown in the figure, heat outlet holes 4 are densely arranged on the side walls of the heating cavity 34 and the U-shaped channel 35.

[0025] When heat-treating cold-bent steel pipes during operation, first connect the end of the heating tube 3 away from the motor 2 to the fan duct, and adjust the buttons on the integrated control panel 15 to put the treatment tank 1 into heat treatment mode. In heat treatment mode, heater 32 is activated, emitting heat that enters the heating chamber 34 through the air outlet 31 and then enters the treatment tank 1 through the heat outlet 4. The temperature inside the treatment tank 1 gradually increases, and temperature sensor 23 senses the temperature in real time and transmits it to the display screen of the integrated control console 15. This means that the optimal heat treatment temperature can be adjusted in a timely manner according to the different models of cold-bent steel pipes, so as to achieve better heat treatment results for the cold-bent steel pipes. After the temperature inside the treatment tank 1 reaches the specified temperature, the cover plate 13 is moved a corresponding distance by pulling ring 14 according to the size of the cold-bent steel pipe, so that the size of the exposed inlet 12 matches the size of the cold-bent steel pipe. In other words, the size of the inlet 12 can be adjusted according to the size of the cold-bent steel pipe to be heat-treated, which can effectively reduce the heat loss inside the treatment tank 1, facilitate energy saving and maintain the thermal balance inside the treatment tank 1, thereby ensuring the heat treatment quality of the cold-bent steel pipe. The design of the heat outlet 4 allows the hot air to be slowly dissipated through the heat outlet 4 under the action of the airflow sent by the fan, which can ensure that there is always appropriate heat in the treatment tank 1, and can carry the heat to the cold pipe steel pipe that rotates with the partition fan 22 to perform heat treatment, which can further promote the heat treatment effect of cold-bent steel pipe, making it more practical and efficient.

[0026] As an embodiment of the present invention, as shown in the figure, an inverted cone ring 5 is fixedly connected to the outer wall of the rotating drum 21. The slope of the inverted cone ring 5 is inclined towards the center of the rotating drum 21 with the direction away from the motor 2 as a reference. The upper end of the processing tank 1 is detachably connected to the side near the integrated control console 15.

[0027] Each of the air outlets 31 is fixedly connected to an air guide ring 6 inside the heating tube 3. The diameter of the hollow ring opening inside the multiple air guide rings 6 decreases sequentially with respect to the direction away from the motor 2.

[0028] During operation, the diameter of the hollow openings inside the multiple air guide rings 6 decreases sequentially with respect to the direction away from the motor 2. This means that as the airflow moves into the heating tube 3, the area inside the heating tube 3 decreases sequentially along the direction of the airflow. In other words, the area of ​​the air guide rings 6 inside the heating tube 3 increases as the airflow moves along the direction of the airflow. When the airflow flows inside the heating tube 3, the air guide rings 6 will successively intercept the same portion of the airflow, carrying heat through the air outlet 31 into the heating chamber 34, which can promote the thermal balance of each area in the zone fan 22.

[0029] As an embodiment of the present invention, as shown in the figure, the rotating drum 21 has a turning hole 7 on the side near the motor 2, and the processing tank 1 has an air outlet channel 71. The turning hole 7 is used to connect the air outlet channel 71 and the heating tube 3. The bottom of the air outlet channel 71 is detachably connected to a sealing block 72.

[0030] When in operation, the sealing block 72 is removed, and the airflow flows inside the heating tube 3. After being intercepted by multiple air guide rings 6 in sequence, the remaining small amount of airflow carrying heat will enter the air outlet channel 71 through the turning hole 7 and flow downwards, and finally flow downwards out of the air outlet channel 71. This guides the airflow carrying heat to the bottom of the equipment, which can prevent burns to nearby staff and make it safer.

[0031] As an embodiment of the present invention, as shown in the figure, the processing tank 1 has a shaped cavity 8, the lower end of the shaped cavity 8 is connected to the air outlet channel 71, and an air inlet 81 is provided on the side wall between the shaped cavity 8 and the inlet 12.

[0032] During operation, the air outlet duct 71 and the irregular cavity 8 are connected. When the airflow carrying heat flows downward in the air outlet duct 71, a negative pressure is generated in the irregular cavity 8 above the air outlet duct 71. This causes the heat from the side of the inlet 12 to enter the irregular cavity 8 through the air inlet 81 and finally flow out through the air outlet 71. This can reduce the temperature at the inlet 12 and prevent heat loss to the conveying equipment above when it is transported by the conveying equipment, or burns to the staff when it is transported manually. It is practical and efficient. After heat treatment, the cold-bent steel pipe needs to be cooled to ensure sufficient microstructure transformation and eliminate secondary stress. At this time, the processing tank 1 is adjusted to the cooling mode after heat treatment by controlling the button on the integrated control console 15. In the cooling mode after heat treatment, the motor 2 starts working normally. The air outlet channel 71 is closed by the sealing block 72, and the heater 32 is turned off and not started. The inlet 12 can be opened to a greater distance by pulling the pull ring 14 as needed to accelerate heat dissipation. The fan forces air into the heating pipe 3, and the strong airflow is sent into the heating chamber 34 and the return channel 35 through the air guide ring 6 and then sprayed out through the heat outlet hole 4, thereby forcibly cooling the heat-treated cold-bent steel pipe as the partition fan 22 rotates. The cooling effect is determined by controlling the wind force of the airflow sent by the fan.

[0033] As an embodiment of the present invention, as shown in the figure, slides 91 are provided on both sides of the inlet 12, and guide rails 9 are fixedly connected to both sides of the cover plate 13. The guide rails 9 extend through the slides 91 and are slidably connected to the slides 91.

[0034] A heat treatment method for cold-bent steel pipes, wherein the method is a method of using a heat treatment device for cold-bent steel pipes.

[0035] Working principle: When heat treatment is to be performed on cold-bent steel pipes, first connect the end of the heating tube 3 away from the motor 2 to the fan duct, and adjust the buttons on the integrated control panel 15 to put the treatment tank 1 into heat treatment mode. In heat treatment mode, heater 32 is activated, emitting heat that enters the heating chamber 34 through the air outlet 31 and then enters the treatment tank 1 through the heat outlet 4. The temperature inside the treatment tank 1 gradually increases, and temperature sensor 23 senses the temperature in real time and transmits it to the display screen of the integrated control console 15. This means that the optimal heat treatment temperature can be adjusted in a timely manner according to the different models of cold-bent steel pipes, so as to achieve better heat treatment results for the cold-bent steel pipes. After the temperature inside the treatment tank 1 reaches the specified temperature, the cover plate 13 is moved a corresponding distance by pulling ring 14 according to the size of the cold-bent steel pipe, so that the size of the exposed inlet 12 matches the size of the cold-bent steel pipe. In other words, the size of the inlet 12 can be adjusted according to the size of the cold-bent steel pipe to be heat-treated, which can effectively reduce the heat loss inside the treatment tank 1, facilitate energy saving and maintain the thermal balance inside the treatment tank 1, thereby ensuring the heat treatment quality of the cold-bent steel pipe. Temperature sensor 23 is used to detect the temperature field inside the processing tank 1. The axial and radial temperature difference inside the tank can be controlled within ±5℃. Compared with the traditional batch heat treatment device, the temperature difference is reduced by more than 60%. The heating consistency of each part of the cold-bent steel pipe is greatly improved, effectively avoiding local overheating or insufficient heat treatment. The uniformity of metallographic structure and the effect of residual stress elimination are significantly improved. Start motor 2. The output shaft of motor 2 drives the rotating drum 21 to rotate slowly. The partition fan 22 fixedly connected to the outside of the rotating drum 21 rotates slowly. After the steel pipe is cold-bent, it can be directly transported to the inlet 12 through the conveying equipment. Then it can directly enter the processing tank 1 through the inlet 12 for heat treatment. It can perform heat treatment immediately after cold bending a steel pipe, instead of waiting for a batch of cold-bent steel pipes to be concentrated for heat treatment. This can ensure the quality of cold bending and heat treatment of steel pipes. The partition fan 22 divides the space inside the processing tank 1 into several rotatable and movable spaces. When a cold-bent steel pipe falls into the processing tank 1, it will fall into one of the spaces divided by the partition fan 22. Then, as the partition fan 22 rotates, it will carry the cold-bent steel pipe away from that space. Under the action of the inverted cone ring 5, the cold-bent steel pipe will slide downwards due to its own gravity and eventually fall to the other side of the processing tank 1. Then, the next cold-bent steel pipe will fall into the space divided by the partition fan 22, and so on. This can prevent the cold-bent steel pipes from being concentrated and blocked at the entrance 12 of the processing tank 1 when they fall into the processing tank 1; it can also prevent large collisions between the cold-bent steel pipes, thereby preventing stress damage to the cold-bent steel pipes; and it can automatically transport the cold-bent steel pipes to places inside the processing tank 1 that the cold-bent steel pipes cannot fall into, thus saving space and being practical and efficient. The partition fan 22 is made of 310S stainless steel (06Cr25Ni20Si2), which facilitates heat conduction and allows for better heat treatment of cold-bent steel pipes. The thermal conductivity of 310S stainless steel increases with temperature (reaching 21.5 W / (m・K) at 500℃), complementing the heat transfer of the hot air in the heating chamber 34. This allows for rapid heat transfer from the chamber to the fan surface, achieving contact heat transfer with the cold-bent steel pipe and improving heat treatment efficiency. 310S stainless steel can also operate stably at temperatures below 800℃ for extended periods, fully covering the heat treatment temperature requirements of the cold-bent steel pipe, and exhibits no significant thermal deformation during temperature cycling. As an austenitic chromium-nickel stainless steel, the austenitic structure provides excellent impact resistance, allowing it to withstand minor impacts to the cold-bent steel pipe. Furthermore, a dense chromium oxide protective film easily forms on the surface, providing oxidation and corrosion resistance and preventing oxide scale from detaching and contaminating the cold-bent steel pipe. Compared to nickel-based alloys, 310S stainless steel is more cost-effective, meeting the industrial production needs of cold-bent steel pipes. It also has good machinability, allowing for precise fabrication of the heating chamber 34, the U-shaped channel 35, and the heat outlet hole 4. By reducing heat loss through adjustable inlet 12, realizing waste heat recycling through irregular cavity structure 8, and enhancing heat conduction through 310S stainless steel partition fan 22, the overall unit product energy consumption is reduced by more than 35%, the heating speed is increased by more than 20%, and the energy-saving effect is outstanding. Multiple heaters 32 are connected in series through insulated wires 33, which can effectively and quickly dissipate heat. Each heater 32 is provided with an air outlet 31, which can more efficiently send heat into the heating chamber 34 through the air outlet 31. When the fan is working, it slowly blows air into the heating tube 3. The airflow moves inside the heating tube 3 and, under the action of the air guide ring 6, carries the heat through the air outlet 31 and sends it into the heating chamber 34 so as to facilitate rapid heat transfer to the partition fan 22. The design of the U-shaped channel 35 can connect multiple heating chambers 34, thereby making the heat in the multiple heating chambers 34 more uniform. The U-shaped channel 35 itself can also promote the rapid heat transfer of the partition fan 22, so that the cold-bent steel pipes in each section of the partition fan 22 are heated to the same degree, and all of them are at the optimal heat treatment temperature of this type of cold-bent steel pipe. The design of the heat outlet 4 allows the hot air to be slowly dissipated through the heat outlet 4 under the action of the airflow sent by the fan, which can ensure that there is always appropriate heat in the treatment tank 1, and can carry the heat to the cold pipe steel pipe cylinder position that rotates with the partition fan 22, which can further promote the heat treatment effect of cold-bent steel pipe, making it more practical and efficient. The diameter of the hollow ring openings inside the multiple air guide rings 6 decreases sequentially with respect to the direction away from the motor 2. That is, when the airflow moves into the heating tube 3, the area inside the heating tube 3 decreases sequentially along the direction of the airflow. In other words, the ring area of ​​the air guide rings 6 inside the heating tube 3 increases as the airflow moves along the direction of the airflow. When the airflow flows in the heating tube 3, the air guide rings 6 will successively intercept the same portion of the airflow, carrying heat through the air outlet 31 into the heating chamber 34, which can promote the thermal balance of each area in the partition fan 22. After removing the sealing block 72, the airflow flows inside the heating tube 3. After being intercepted by multiple air guide rings 6 in sequence, the remaining small amount of airflow carrying heat will enter the air outlet channel 71 through the turning hole 7 and flow downwards, and finally flow downwards out of the air outlet channel 71. This guides the airflow carrying heat to the bottom of the equipment, which can prevent burns to nearby staff and make it safer. The air outlet duct 71 and the irregular cavity 8 are connected. When the airflow carrying heat flows downward in the air outlet duct 71, a negative pressure is generated in the irregular cavity 8 above the air outlet duct 71. This causes the heat from the side of the inlet 12 to enter the irregular cavity 8 through the air inlet 81 and finally flow out through the air outlet duct 71. This can reduce the temperature at the inlet 12 and prevent heat loss to the conveying equipment above when it is transported by the conveying equipment, or burns to the staff when it is transported manually. It is practical and efficient. After heat treatment, the cold-bent steel pipe needs to be cooled to ensure sufficient microstructure transformation and eliminate secondary stress. At this time, the processing tank 1 is adjusted to the cooling mode after heat treatment by controlling the button on the integrated control console 15. In the cooling mode after heat treatment, the motor 2 starts working normally. The air outlet channel 71 is closed by the sealing block 72, and the heater 32 is turned off and not started. The inlet 12 can be opened to a greater distance by pulling the pull ring 14 as needed to accelerate heat dissipation. The fan forces air into the heating pipe 3, and the strong airflow is sent into the heating chamber 34 and the return channel 35 through the air guide ring 6 and then sprayed out through the heat outlet hole 4, thereby forcibly cooling the heat-treated cold-bent steel pipe as the partition fan 22 rotates. The cooling effect is determined by controlling the wind force of the airflow sent by the fan.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A heat treatment apparatus for cold-bent steel pipes, comprising a treatment tank (1), characterized in that: The bottom of the treatment tank (1) is symmetrically fixedly connected with a bracket (11). The upper end of the treatment tank (1) is provided with an inlet (12) for cold-bent steel pipes to pass through. A cover plate (13) is slidably connected to the inlet (12), and the cover plate (13) extends through and extends out of the inlet (12) and is slidably connected to the inlet (12). A pull ring (14) is fixedly connected to one end of the cover plate (13) extending out of the inlet (12). An integrated control console (15) is fixedly connected to the upper end of one side of the treatment tank (1). A heating element is provided inside the treatment tank (1).

2. The heat treatment apparatus for cold-bent steel pipes according to claim 1, characterized in that: A rotating drum (21) extends through and is rotatably connected to the processing tank (1). A motor (2) is fixedly connected to one end of the rotating drum (21) extending through the processing tank (1). The motor (2) is electrically connected to the integrated control console (15). Multiple partition fans (22) are fixedly connected in a ring at equal intervals on the outer wall of the rotating drum (21). A temperature sensor (23) is embedded in the inner wall of the processing tank (1). The temperature sensor (23) is electrically connected to the integrated control console (15). The partition fans (22) are made of 310S stainless steel.

3. The heat treatment apparatus for cold-bent steel pipes according to claim 2, characterized in that: The heating element includes a heating tube (3), which is sleeved inside a rotating drum (21). One end of the heating tube (3) extends out of the rotating drum (21) and passes through the processing tank (1) and is fixedly connected to the processing tank (1). The inner wall of the heating tube (3) is provided with multiple air outlets (31) at equal intervals in an annular shape. Each air outlet (31) is adjacent to a heater (32). The heater (32) is annular and fixedly connected to the side wall of the heating tube (3). The multiple heaters (32) are electrically connected to each other by heat-insulating wires (33). The heaters (32) are electrically connected to the integrated control console (15). Each partition fan (22) is provided with multiple heating chambers (34) at equal intervals, and each partition fan (22) is provided with a loop channel (35). The loop channel (35) is connected to the heating chamber (34).

4. The heat treatment apparatus for cold-bent steel pipes according to claim 3, characterized in that: Heat outlet holes (4) are densely arranged on the side walls of the heating chamber (34) and the U-shaped channel (35).

5. The heat treatment apparatus for cold-bent steel pipes according to claim 4, characterized in that: An inverted cone ring (5) is fixedly connected to the outer wall of the rotating drum (21). The slope of the inverted cone ring (5) is inclined towards the center of the rotating drum (21) with the direction away from the motor (2) as the reference. A bucket (51) is detachably connected to the upper end of the processing tank (1) near the integrated control console (15).

6. The heat treatment apparatus for cold-bent steel pipes according to claim 5, characterized in that: Each of the air outlets (31) is fixedly connected to an air guide ring (6) inside the heating tube (3). The diameter of the hollow ring opening inside the multiple air guide rings (6) decreases sequentially with respect to the direction away from the motor (2).

7. The heat treatment apparatus for cold-bent steel pipes according to claim 6, characterized in that: The rotating drum (21) has a turning hole (7) on the side near the motor (2), and the processing tank (1) has an air outlet channel (71). The turning hole (7) is used to connect the air outlet channel (71) and the heating tube (3). The bottom of the air outlet channel (71) is detachably connected to a sealing block (72).

8. The heat treatment apparatus for cold-bent steel pipes according to claim 7, characterized in that: The processing tank (1) has an irregular cavity (8) inside, the lower end of the irregular cavity (8) is connected to the air outlet channel (71), and an air inlet (81) is provided on the side wall between the irregular cavity (8) and the inlet (12).

9. The heat treatment apparatus for cold-bent steel pipes according to claim 1, characterized in that: The entrance (12) has slides (91) on both sides, and the cover plate (13) has guide rails (9) fixedly connected to both sides. The guide rails (9) extend through the slides (91) and are slidably connected to the slides (91).

10. A heat treatment method for cold-formed steel pipes, applied to the heat treatment apparatus for cold-formed steel pipes as described in any one of claims 1-9, characterized in that, The method described is the usage method of the heat treatment device for cold-bent steel pipes.

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