Roller heat treatment device and treatment method

Abstract

The present application relates to the technical field of roller heat treatment, and discloses a roller heat treatment device and a treatment method. The roller heat treatment device comprises a kiln main body, a loading trolley for carrying the roller and entering and leaving a heat treatment chamber, and a heat treatment mechanism for heating the heat treatment chamber; the heat treatment mechanism comprises a plurality of heating units, a gas supply unit, a temperature sensing unit and a control unit; the plurality of heating units are linearly, uniformly and equidistantly distributed along the length direction of the kiln main body. The present application realizes accurate regulation and control of the three-dimensional temperature field in the furnace by means of the three-layer layout of the top first heating nozzle part, the side wall second heating nozzle part with adjustable angle and the bottom third heating nozzle part, and the dynamic angle adjustment of the second heating nozzle part, the main flow field formed by the top nozzle, the dynamic compensation of the local temperature difference by the side wall adjustable nozzle and the compensation of the low-temperature area caused by the heat absorption of the trolley by the bottom nozzle, so that the temperature difference in the working area of the furnace can be greatly reduced, and the hardness deviation of the roller surface can be reduced.

Description

Technical Field

[0001] This invention relates to the field of heat treatment technology for rolling mill rolls, and more specifically, to a heat treatment apparatus and method for rolling mill rolls. Background Technology

[0002] Rolls are crucial components of rolling mills, and the quality of their heat treatment directly affects their service life and the surface quality of the rolled products. Car-type heat treatment kilns are commonly used equipment for roll heat treatment, employing burners to heat, hold, and cool the rolls.

[0003] In existing technologies, traditional roll heat treatment kilns typically use fixed-angle burners for heating. However, while fixed-angle burners can meet most processing requirements, they still have certain shortcomings in practical use. For example, they cannot adapt to the heating needs of rolls with different diameters, and the hot airflow is prone to creating blind spots, resulting in large temperature differences within the working area of ​​the furnace, which in turn leads to uneven heating of the roll body, roll neck, and roll head. In addition, since the optimal heat flow direction differs in each stage of heat treatment—heating, holding, and cooling—traditional fixed burners cannot adjust the airflow direction according to the process, failing to eliminate dynamic temperature deviations and easily causing localized overheating or underheating problems.

[0004] Therefore, there is an urgent need for a heat treatment device and method for rolls that can improve the uniformity of the temperature field inside the furnace during the heat treatment of rolls and achieve precise temperature control for rolls of different specifications and at different process stages. Summary of the Invention

[0005] The purpose of this invention is to provide a heat treatment apparatus and method for rolling mill rolls to solve the aforementioned technical problems.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions: This invention provides a heat treatment apparatus for rolling mill rolls, comprising: a kiln body, a loading trolley for carrying rolling mill rolls and moving them into and out of a heat treatment chamber, and a heat treatment mechanism for heating the heat treatment chamber. The heat treatment mechanism includes multiple heating units, gas supply units, temperature sensing units, and control units; Multiple heating units are linearly and uniformly distributed along the length of the kiln body. Each heating unit includes a first heating nozzle, two second heating nozzles, and two third heating nozzles. The first heating nozzle is installed on the top of the inner wall of the heat treatment chamber. The two second heating nozzles and the two third heating nozzles are symmetrically installed on two opposite side walls of the heat treatment chamber, and the third heating nozzle is located below the second heating nozzle on the same side. The second heating nozzle includes a nozzle body rotatably mounted on the side wall of the kiln body, a drive structure for driving the nozzle body to rotate, and an angle detection element for real-time detection of the current angle of the nozzle body. The temperature sensing unit is used to collect temperature data in the heat treatment chamber and surface temperature data of the rolls in real time. The control unit is communicatively connected to the drive structure, the angle detection element, and the temperature sensing unit, and is configured to: receive temperature data collected by the temperature sensing unit and the current angle fed back by the angle detection element; determine the target adjustment angle based on the preset heat treatment process curve and the received temperature data; and send a control command to the drive structure according to the target adjustment angle to drive the nozzle body to rotate to the target position.

[0007] Preferably, the drive structure includes a servo motor installed on the outside of the kiln body and a heat-insulating sealing sleeve fitted on the nozzle body, and the output end of the servo motor is connected to the nozzle body through a connecting rod.

[0008] Preferably, the heat-insulating sealing sleeve is a high-temperature resistant metal bellows, and the inner wall of the bellows is provided with multiple layers of flexible ceramic fiber sealing gaskets.

[0009] Preferably, the temperature sensing unit includes multiple thermocouples distributed in different spatial positions within the heat treatment chamber and at least one infrared pyrometer for collecting surface temperature data of the roll.

[0010] Preferably, the angle detection element is an absolute encoder connected to the nozzle body.

[0011] Preferably, the first heating nozzle is a fixed high-speed nozzle with its opening vertically downward, and the third heating nozzle is a fixed small-diameter nozzle with its opening facing the loading trolley bearing surface.

[0012] Preferably, the gas supply unit is connected to each heating unit through a gas pipeline, and each gas pipeline is equipped with a flow regulating valve.

[0013] Secondly, the present invention also provides a method for heat treatment of rolls based on the aforementioned device, comprising the following steps: Step S1: Obtain the specification parameters of the roll to be processed and the preset heat treatment process curve; Step S2: Set the initial spray angle of each second heating nozzle according to the specifications of the roll. Step S3: During the heat treatment process, the temperature data inside the heat treatment chamber and the surface temperature data of the roll are collected in real time. Step S4: Based on the deviation between the real-time collected temperature data and the target temperature in the heat treatment process curve, and the current heat treatment process stage, calculate the target adjustment angle of each second heating nozzle in real time, and drive the nozzle body to rotate to the target adjustment angle. Step S5: Repeat steps S3 and S4 until the heat treatment process is complete.

[0014] Preferably, in step S4, the target adjustment angle is calculated using the following adaptive adjustment algorithm: Calculate temperature deviation ,in The target temperature for the process, The actual temperature of the target area; Calculate the single angle adjustment amount using the following formula. :

[0015] in, This is a correction factor for the process stage. C1 is the safety limiting factor, C2 is the temperature deviation sensitivity factor, C3 is the spatial position correction factor, C4 is the integral compensation factor, H is the vertical height difference between the center of the nozzle body and the center of the roll, and L is the horizontal distance from the center of the nozzle body to the center of the roll. The integral term accumulates the temperature deviation over a period of time. Based on the single angle adjustment amount and current angle Calculate the target adjustment angle and to Perform a safety limit within the range of 0° to 60°.

[0016] Preferably, while adjusting the angle of the nozzle body, the control unit also simultaneously adjusts the gas flow rate and combustion air flow rate of the corresponding heating unit to maintain a preset air-fuel ratio.

[0017] The beneficial effects of this invention are as follows: This invention achieves precise control of the three-dimensional temperature field inside the furnace by setting up a three-layer layout of a top first heating nozzle, a side wall adjustable angle second heating nozzle, and a bottom third heating nozzle, combined with the dynamic angle adjustment of the second heating nozzle. The top nozzle forms the main temperature field, the side wall adjustable nozzle dynamically compensates for local temperature differences, and the bottom nozzle compensates for the low temperature zone caused by the heat absorption of the trolley. This can significantly reduce the temperature difference in the working area inside the furnace, thereby reducing the surface hardness deviation of the rolls. In addition, the control unit set in this invention dynamically calculates the target angle of the second heating nozzle based on real-time collected temperature data and preset process curves through an adaptive adjustment algorithm, so that the heat flow direction is automatically adjusted with the process stage, which solves the defect that traditional fixed burners cannot dynamically respond to temperature changes and achieves high-precision temperature control. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the overall structure of a heat treatment device for rolling mills according to the present invention; Figure 2 This is a side view of a heat treatment apparatus for rolling mills according to the present invention; Figure 3 This is the present invention. Figure 2 Cross-sectional view of plane AA; Figure 4 This is the present invention. Figure 3 A magnified view of a portion of point a; Figure 5 This is a block diagram showing the module connection of the control system in an embodiment of the present invention; Figure 6 This is a schematic flowchart of the heat treatment method for rolling mill rolls provided in an embodiment of the present invention.

[0019] In the diagram: 10. Kiln body; 101. Heat treatment chamber; 20. Loading trolley; 30. Heat treatment mechanism; 301. First heating nozzle; 302. Second heating nozzle; 3021. Nozzle body; 3022. Servo motor; 3023. Heat insulation sealing sleeve; 3024. Connecting rod; 3025. Thermocouple; 3026. Infrared pyrometer; 3027. Absolute encoder; 303. Third heating nozzle. Detailed Implementation

[0020] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0021] Example 1 Firstly, please refer to the following: Figures 1 to 5 The present invention provides a heat treatment device for rolling mill rolls, comprising: a kiln body 10, a loading trolley 20, and a heat treatment mechanism 30.

[0022] The kiln body 10 has a heat treatment chamber 101 inside, which is used to accommodate the rolls to be treated. The loading trolley 20 is used to carry the rolls and can move in and out of the heat treatment chamber 101 along the track. The bearing surface of the loading trolley 20 can adopt a low heat storage honeycomb ceramic support structure to reduce the contact thermal resistance with the rolls.

[0023] The heat treatment mechanism 30 is used to heat the heat treatment chamber 101, and includes multiple heating units, a gas supply unit, a temperature sensing unit, and a control unit.

[0024] Multiple heating units are linearly and uniformly distributed at equal intervals along the length of the kiln body 10. In this embodiment, the number of heating units is six, but in actual applications, it can be set to four, five or more depending on the kiln length and production capacity requirements, all of which fall within the protection scope of this invention.

[0025] Each heating unit includes a first heating nozzle 301, two second heating nozzles 302, and two third heating nozzles 303. The first heating nozzle 301 is installed on the top of the inner wall of the heat treatment chamber 101, with its opening vertically downward, to form the main heating flow field inside the furnace. In this embodiment, the first heating nozzle 301 is a fixed high-speed nozzle, which can generate high-speed airflow and enhance convective heat transfer inside the furnace.

[0026] Two second heating nozzles 302 and two third heating nozzles 303 are symmetrically mounted on two opposite side walls of the heat treatment chamber 101. Specifically, each side wall has one second heating nozzle 302 and one third heating nozzle 303, with the third heating nozzle 303 located below the second heating nozzle 302 on the same side. The third heating nozzle 303 is a fixed-diameter nozzle with its opening facing the bearing surface of the loading trolley 20 after entering the heat treatment chamber 101, and is used to directly heat the loading trolley 20 to compensate for heat loss caused by heat absorption by the trolley and eliminate the low-temperature zone at the bottom.

[0027] The second heating nozzle component 302 includes a nozzle body 3021, a drive structure, and an angle detection element.

[0028] The nozzle body 3021 is rotatably mounted on the side wall of the kiln body 10 through a hinge connection structure, and can achieve angle adjustment within the range of 0° to 60° (0° is horizontal towards the inside of the kiln, and downward tilt is the positive direction).

[0029] The drive structure is used to drive the nozzle body 3021 to rotate. In this embodiment, the drive structure includes a servo motor 3022 installed on the outside of the kiln body 10. The output end of the servo motor 3022 is connected to the nozzle body 3021 via a connecting rod 3024. By adopting the transmission method of the servo motor 3022 and the connecting rod 3024, the drive mechanism is arranged in the ambient temperature zone outside the furnace, avoiding damage to electrical components from high temperatures and facilitating daily maintenance. The servo motor 3022 has a built-in precision planetary reducer to ensure smooth start-up and shutdown and adjustment accuracy.

[0030] An angle detection element is used to detect the current angle of the nozzle body 3021 in real time. In this embodiment, the angle detection element is an absolute encoder 3027 connected to the nozzle body 3021, which can directly feed back the absolute angular position of the nozzle body 3021 to achieve closed-loop position control.

[0031] To ensure sealing during nozzle rotation, this embodiment also includes a heat-insulating sealing sleeve 3023 fitted onto the nozzle body 3021. Specifically, the heat-insulating sealing sleeve 3023 is fitted onto the portion of the nozzle body 3021 that extends beyond the side wall of the kiln body 10. In this embodiment, the heat-insulating sealing sleeve 3023 is made of a high-temperature resistant metal bellows, and the inner wall of the bellows is provided with multiple layers of flexible ceramic fiber sealing gaskets. This structure not only satisfies the rotational freedom of the nozzle body 3021 within the range of 0° to 60°, but also completely blocks the leakage of high-temperature flue gas inside the furnace, significantly reducing heat leakage loss.

[0032] The temperature sensing unit is used to collect real-time temperature data within the heat treatment chamber 101 and surface temperature data of the rolls. In this embodiment, the temperature sensing unit includes multiple thermocouples 3025 and at least one infrared pyrometer 3026.

[0033] Multiple thermocouples 3025 are distributed in different spatial positions within the heat treatment chamber 101. For example, 8 to 12 K-type armored thermocouples 3025 are arranged along the length direction (front, middle, and rear) and the height direction (upper, middle, and lower), with a temperature resistance of ≥1300℃, to construct the basic data for the three-dimensional temperature field inside the furnace.

[0034] An infrared pyrometer 3026 is installed on the inner wall of the kiln body 10 for non-contact real-time acquisition of surface temperature data of the rolls, especially the temperature of the middle and end necks of the roll body. In this embodiment, a dual-color infrared pyrometer 3026 is used to directly provide feedback on the heating status of the workpiece.

[0035] The control unit uses a conventional industrial PLC with a built-in adaptive adjustment algorithm program, and communicates with the drive structure, angle detection element and temperature sensing unit respectively.

[0036] The control unit is configured to perform the following core functions: It receives temperature data collected by the temperature sensing unit and the current angle fed back by the angle detection element; Based on the preset heat treatment process curve and the received temperature data, the target adjustment angle is determined; According to the target adjustment angle, a control command is sent to the drive structure to drive the nozzle body 3021 to rotate to the target position.

[0037] The gas supply unit is connected to each heating unit via gas pipelines. Each gas pipeline is equipped with a flow regulating valve to independently control the gas flow and combustion air flow of each heating nozzle, thereby achieving zoned combustion control.

[0038] Example 2 like Figure 6 As shown, based on the above-described apparatus, the present invention also provides a method for heat treatment of rolling mill rolls, comprising the following steps: Step S1: Obtain the specification parameters of the roll to be processed and the preset heat treatment process curve.

[0039] Operators input specifications such as diameter, length, and material of the roll to be processed through a human-machine interface, and retrieve the corresponding heat treatment process curve (including target temperature, holding time, heating rate, etc.) from the process database.

[0040] Step S2: Set the initial spray angle of each second heating nozzle 302 according to the specifications of the roll.

[0041] Based on the roll diameter D, the control unit automatically calculates the vertical height difference H between the center of the nozzle body 3021 and the center of the roll (which can be calculated given the burner installation height and the roll diameter), and assigns an initial spray angle to each second heating nozzle 302 through a preset spatial position correction model; for example, for small-diameter rolls, the initial angle is smaller, so that the heat flow is directly aligned with the roll; for large-diameter rolls, the initial angle is larger, so that the heat flow covers a wider range.

[0042] Step S3: During the heat treatment process, the temperature data inside the heat treatment chamber 101 and the surface temperature data of the roll are collected in real time.

[0043] The control unit collects temperature data from all thermocouples 3025 and infrared pyrometers 3026 in a cyclical manner according to a set period, and performs filtering to eliminate on-site interference.

[0044] Step S4: Based on the deviation between the real-time collected temperature data and the target temperature in the heat treatment process curve, as well as the current heat treatment process stage, calculate the target adjustment angle of each second heating nozzle 302 in real time, and drive the nozzle body 3021 to rotate to the target adjustment angle.

[0045] In this step, the control unit uses an adaptive adjustment algorithm to calculate the target adjustment angle, specifically: First, calculate the temperature deviation. ,in The target temperature for the process (determined based on the process curve and the current time). The actual temperature of the target area (which can be determined based on the data from the infrared pyrometer 3026 or the corresponding thermocouple 3025).

[0046] Secondly, calculate the single angle adjustment amount according to the following formula. :

[0047] The physical meaning and values ​​of each parameter in the formula are shown below: This is a correction factor for each process stage. It is set to 1.2 for the heating stage, 0.8 for the holding stage, and 0.5 for the cooling stage, to match the adjustment range required for different stages.

[0048] The safety limiting factor is fixed at 0.9 to limit the maximum adjustment amount in a single instance and prevent system oscillation.

[0049] C1 is the temperature deviation sensitivity coefficient, the field calibration value, with an initial recommendation of 0.8 and a range of 0.5~1.0.

[0050] C2: Spatial position correction factor, field calibration value, initial recommendation 0.4, range 0.3~0.5.

[0051] C3: Integral compensation coefficient, used to eliminate steady-state error, initial recommended value is 0.05, range is 0.02~0.1.

[0052] H is the vertical height difference between the center of the nozzle body 3021 and the center of the roll, which is calculated from the roll diameter and the burner installation position.

[0053] L is the horizontal distance from the center of the nozzle body 3021 to the center of the roll, which is a fixed value of the furnace structure.

[0054] This is the integral term, which accumulates the temperature deviation over a past period.

[0055] Then, calculate the target adjustment angle. ,in The current angle (feedback from the angle detection element). Finally, for Apply a safety limit within the range of 0° to 60° to ensure that the mechanical travel is not exceeded.

[0056] While adjusting the angle of the nozzle body 3021, the control unit also simultaneously adjusts the gas flow rate and combustion air flow rate of the corresponding heating unit to maintain the preset air-fuel ratio and ensure combustion efficiency and flame stability.

[0057] Step S5: Repeat steps S3 and S4 until the heat treatment process is complete.

[0058] The system continuously performs closed-loop control of data acquisition, calculation, adjustment, and feedback until the heat treatment time ends, thus completing the entire heat treatment process.

[0059] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. A heat treatment apparatus for rolling mill rolls, characterized in that, include: The kiln body, the loading trolley for carrying the rolls and moving them in and out of the heat treatment chamber, and the heat treatment mechanism for heating the heat treatment chamber; The heat treatment mechanism includes multiple heating units, gas supply units, temperature sensing units, and control units; Multiple heating units are linearly and uniformly distributed along the length of the kiln body. Each heating unit includes a first heating nozzle, two second heating nozzles, and two third heating nozzles. The first heating nozzle is installed on the top of the inner wall of the heat treatment chamber. The two second heating nozzles and the two third heating nozzles are symmetrically installed on two opposite side walls of the heat treatment chamber, and the third heating nozzle is located below the second heating nozzle on the same side. The second heating nozzle includes a nozzle body rotatably mounted on the side wall of the kiln body, a drive structure for driving the nozzle body to rotate, and an angle detection element for real-time detection of the current angle of the nozzle body; the temperature sensing unit is used to collect temperature data in the heat treatment chamber and surface temperature data of the rolls in real time; the control unit is communicatively connected to the drive structure, the angle detection element, and the temperature sensing unit, and is configured to: receive temperature data collected by the temperature sensing unit and the current angle fed back by the angle detection element; and determine the target adjustment angle based on the preset heat treatment process curve and the received temperature data; Based on the target adjustment angle, control commands are sent to the drive structure to drive the nozzle body to rotate to the target position.

2. The heat treatment apparatus for rolling mill rolls according to claim 1, characterized in that, The drive structure includes a servo motor installed on the outside of the kiln body and a heat-insulating sealing sleeve fitted on the nozzle body. The output end of the servo motor is connected to the nozzle body through a connecting rod.

3. The heat treatment apparatus for rolling mill rolls according to claim 2, characterized in that, The heat-insulating sealing sleeve is a high-temperature resistant metal bellows, and the inner wall of the bellows is provided with multiple layers of flexible ceramic fiber sealing gaskets.

4. The heat treatment apparatus for rolling mill rolls according to claim 1, characterized in that, The temperature sensing unit includes multiple thermocouples distributed in different spatial positions within the heat treatment chamber and at least one infrared pyrometer for collecting surface temperature data of the rolls.

5. The heat treatment apparatus for rolling mill rolls according to claim 1, characterized in that, The angle detection element is an absolute encoder connected to the nozzle body.

6. The heat treatment apparatus for rolling mill rolls according to claim 1, characterized in that, The first heating nozzle is a fixed high-speed nozzle with its opening vertically downward, and the third heating nozzle is a fixed nozzle with its opening facing the loading trolley bearing surface.

7. The heat treatment apparatus for rolling mill rolls according to claim 1, characterized in that, The gas supply unit is connected to each heating unit through gas pipelines, and each gas pipeline is equipped with a flow regulating valve.

8. A method for heat treating rolls based on the apparatus according to any one of claims 1 to 7, characterized in that, Includes the following steps: Step S1: Obtain the specification parameters of the roll to be processed and the preset heat treatment process curve; Step S2: Set the initial spray angle of each second heating nozzle according to the specifications of the roll. Step S3: During the heat treatment process, the temperature data inside the heat treatment chamber and the surface temperature data of the roll are collected in real time. Step S4: Based on the deviation between the real-time collected temperature data and the target temperature in the heat treatment process curve, and the current heat treatment process stage, calculate the target adjustment angle of each second heating nozzle in real time, and drive the nozzle body to rotate to the target adjustment angle. Step S5: Repeat steps S3 and S4 until the heat treatment process is complete.

9. The method for heat treatment of rolls according to claim 8, characterized in that, In step S4, the target adjustment angle is calculated using the following adaptive adjustment algorithm: Calculate temperature deviation ,in The target temperature for the process, The actual temperature of the target area; Calculate the single angle adjustment amount using the following formula. : in, This is a correction factor for the process stage. C1 is the safety limiting factor, C2 is the temperature deviation sensitivity factor, C3 is the spatial position correction factor, C4 is the integral compensation factor, H is the vertical height difference between the nozzle body center and the roll center, and L is the horizontal distance between the nozzle body center and the roll center. The integral term accumulates the temperature deviation over a period of time. Calculate the target adjustment angle based on the single angle adjustment amount Δθ and the current angle θ0. and to Perform a safety limit within the range of 0° to 60°.

10. The method for heat treatment of rolls according to claim 8, characterized in that, In step S4, while adjusting the angle of the nozzle body, the control unit also simultaneously adjusts the gas flow rate and combustion air flow rate of the corresponding heating unit to maintain the preset air-fuel ratio.

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