Non-contact correction device and method of correction thereof

Abstract

The application discloses a non-contact correcting device and a correcting method thereof, and belongs to the technical field of material processing. The device is composed of a feeding roller way, a heating and heat-preserving furnace, a discharging roller way, a sectional cooling device and a control system, and can perform continuous non-contact correcting treatment on materials in a traveling mode. According to the thermal expansion (or negative thermal expansion) characteristics of the materials and the internal thermal stress action principle of the materials, the cooling sequence of each part of the materials is controlled in the material cooling process, the internal thermal stress generated due to the temperature gradient in the materials is utilized, the materials are deformed by cooling on one side, the original deformation defects of the materials are offset through the cooling deformation, the non-contact correcting purpose is achieved, the correcting rollers are not needed, and the shape, position and size precision and the surface quality of the materials can be improved simultaneously. The application can also realize the synchronization of the solid solution quenching heat treatment and the non-contact correcting process of the materials.

Description

Technical Field

[0001] This invention belongs to the field of materials processing technology, specifically relating to a non-contact correction device and its correction method. Background Technology

[0002] In the field of materials processing, deformation of materials during processing and forming is inevitable. In particular, when metal materials are subjected to external stress during production, they will produce shape defects such as dents and bends, making them unusable or unable to proceed to the next production process. Therefore, correcting deformed materials is extremely important in the field of materials manufacturing.

[0003] Traditional straightening processes involve applying external force to materials through contact straightening using equipment such as straightening rollers and stretching machines. These methods can easily cause irreversible damage to the material's surface quality. Straightening rollers create surface defects such as unevenness, scratches, and roller marks, while stretching machines cause severe clamping marks at the material's clamping ends. This is particularly problematic for materials with excessively high or low yield strength, or excessively thick or thin walls. Even if surface damage is caused, the internal stress within the material cannot be completely eliminated, making straightening impossible. Furthermore, external force stretching and straightening can alter the material's cross-sectional area. Improper control of the stretching rate can result in an excessively small cross-sectional area, rendering the entire material unusable, increasing the difficulty of straightening, and reducing the yield rate.

[0004] The following existing literature on material orthopedics was retrieved:

[0005] 1. Quenching and straightening machine; CN201210055132.5; A quenching and straightening machine, belonging to the field of billet processing machinery. It includes a lower and upper machine base, the lower machine base being mounted on the ground or a support frame, with a set of columns on one side of the lower machine base, and the upper machine base fixed to the set of columns; a set of lower straightening rollers mounted on one side of the lower machine base; a set of upper straightening rollers mounted on one side of the upper machine base; a set of upper straightening roller adjustment mechanisms mounted on the upper machine base; lower and upper straightening roller drive mechanisms respectively mounted on the ground; and a water spraying mechanism including a water inlet pipe and a set of nozzles, the inlet end of the water inlet pipe being connected to a water source pipeline, the set of nozzles being connected to a branch pipe of the water inlet pipe, with a nozzle corresponding to each adjacent lower straightening roller, each nozzle forming a nozzle cavity, and each nozzle forming a jacket, with spray holes opened on the wall of the jacket. Advantages: Improved production efficiency; reduced equipment investment and space occupation in production areas; energy conservation; labor conservation; improved straightening and quenching quality of steel billets; ensured quenching quality.

[0006] 2. Quenching apparatus and quenching method, and method for manufacturing steel plate; CN201980070242.9; Provides a quenching apparatus and quenching method capable of suppressing shape defects generated in a metal plate during quenching, and capable of preventing uneven cooling rate in the width direction of the metal plate while suppressing the reduction of the cooling rate of the metal plate. A quenching apparatus is a quenching apparatus for immersing a high-temperature metal plate in a liquid for cooling, characterized in that it comprises a tank containing the liquid immersing the metal plate, a spraying device partially disposed in the liquid in the tank and having two or more nozzles for spraying the liquid onto the metal plate, and a constraint roller disposed between the inlet side end and the outlet side end of the spraying device and clamping the metal plate from both sides, wherein in the spraying device, the nozzle adjacent to the constraint roller is inclined from the horizontal plane toward the constraint roller, the opening of the nozzle adjacent to the constraint roller is slit-shaped, and the opening width of the opening gradually decreases from the center of the opening in the length direction to the end in the length direction.

[0007] 3. A strip steel quenching and straightening machine and its usage method; CN202010784907.7; A strip steel quenching and straightening machine and its usage method. The strip steel quenching and straightening machine includes a drive device and a pressure quenching section, a warm straightening section, and a roller quenching section sequentially fixed on the frame along the strip steel's travel direction. The pressure quenching section includes multiple first rolling devices spaced apart inside it and one or more pressure quenching spray devices. The warm straightening section includes second rolling devices spaced apart inside it. The roller quenching section includes multiple third rolling devices spaced apart inside it and multiple roller quenching spray devices. The drive device is connected to the rolling devices and drives them to roll. The pressure quenching section, warm straightening section, and roller quenching section are integrated to meet the different equipment and functional requirements of cooling rate, microstructure transformation, and strip shape at different temperature drop stages in the strip steel quenching process, improving strip flatness, making the microstructure fine and uniform, and distributing residual stress evenly, thereby improving strength and toughness.

[0008] 4. A method for leveling aluminum alloy thick plates after quenching; CN202111232647.3; This invention belongs to the field of aluminum alloy processing technology and aims to solve the plate shape problems such as bending, warping, dead bending, and excessive flatness that easily occur in aluminum alloy thick plates after quenching. The leveling method includes: 1. Insulating and quenching the aluminum alloy thick plate; 2. Measuring the flatness of the quenched aluminum alloy plate; 3. Applying different plate shape correction methods to the leveled quenched aluminum alloy plate according to its thickness and flatness. This invention uses three methods—rolling mill straightening, straightening machine straightening, and stretching—to level the plate shape of the quenched aluminum alloy thick plate. The treated plate does not have plate shape problems such as bending, warping, dead bending, and excessive flatness. The flatness problem is solved by reducing the number of rolling mill passes. After the leveling method of this invention, the lateral unevenness of the aluminum alloy sheet is ≤3mm / full width, the lateral unevenness after stretching is ≤3mm / full width, and the longitudinal unevenness after stretching is ≤3mm / full length.

[0009] 5. An integrated method for controlling the shape of quenched steel plates; CN201910106745.9; An integrated method for controlling the shape of quenched steel plates, comprising the following steps: (1) incoming material shape control; (2) shot blasting of the steel plate; (3) heating and quenching based on temperature uniformity; (4) high-intensity cold straightening, thus completing the control of the shape of the quenched steel plate. This invention conducts an extended study on the control of the shape of ultra-thin, ultra-high strength, and wide-specification quenched plates, combined with actual on-site production conditions and the plate shape generation mechanism. Taking into account the influencing factors such as shot blasting process, quenching process, water volume model, and other processes, a comprehensive study and on-site application are carried out.

[0010] All of the above material straightening methods are contact straightening methods, which will cause damage to the material surface and cannot completely eliminate the internal stress in the material. Summary of the Invention

[0011] The purpose of this invention is to provide a non-contact straightening device and its straightening method, which can achieve material straightening without using rigid straightening equipment to contact the material to be straightened, thus achieving the purpose of non-contact straightening, avoiding damage to the material surface, and can synergistically improve the dimensional accuracy and surface quality of the material. This invention can also realize the simultaneous performance of solution quenching heat treatment and non-contact straightening process.

[0012] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0013] A non-contact correction device includes a heating and heat preservation furnace, the outlet of which is connected to a segmented cooling device. The segmented cooling device includes a first cooling channel, a second cooling channel, and a third cooling channel. Each cooling channel has several air nozzles, mist nozzles, or water nozzles arranged in the upper, lower, left, and right directions inside its cavity.

[0014] The amount of cooling medium sprayed from the air nozzle, mist nozzle, or water nozzle can be independently adjusted by the flow valve in the pipeline.

[0015] Depending on the material composition, size, thickness, and deformation, the segmented cooling device selects one or more of the following methods—air cooling, mist cooling, and water cooling—to cool the material, controlling the cooling rate at the initial, middle, and later stages of cooling. When the material characteristics change, the cooling correction parameters can be rapidly adjusted through the control system.

[0016] The inlet of the heating and heat preservation furnace is connected to the inlet roller conveyor, the outlet of the segmented cooling device is connected to the air drying device, and the other end of the air drying device is connected to the outlet roller conveyor.

[0017] The inner cavity of the heating and heat preservation furnace is sequentially equipped with lifting roller conveyor A, translation chain and lifting roller conveyor B according to the material movement direction, wherein lifting roller conveyor A is connected to the feeding roller conveyor and lifting roller conveyor B is connected to the inner roller conveyor of the segmented cooling device.

[0018] The overall control system of the equipment includes a computer, a PLC and necessary connecting wires. The control system controls the lifting roller conveyor, heating and heat preservation furnace, feeding and discharging roller conveyor, segmented cooling device and air drying device. The PLC can store and recall historical correction parameters.

[0019] The heating and heat preservation furnace contains several temperature control zones, each equipped with a heating device, a circulating fan, and a temperature-controlled thermocouple. The heating device heats the air, and the circulating fan circulates hot air longitudinally to heat the material. When the temperature-controlled thermocouple detects a certain temperature, the heating device stops heating, while the circulating fan continues to circulate hot air to maintain a uniform temperature throughout the material.

[0020] The movement process of the material to be corrected in the heating and holding furnace is as follows: Lifting roller A is raised by a cylinder or hydraulic cylinder and kept at the same height as the feeding roller. The material enters the lifting roller A from the feeding roller. Lifting roller A descends, and the material is then supported by a translation chain. The translation chain consists of multiple sets of teeth interlaced and alternately arranged. Multiple sets of translation chains realize the lateral movement of the material. When the material is about to reach the last station, lifting roller B descends and the material enters the area. Lifting roller B is raised, and the material is then supported by lifting roller B and transferred to the segmented cooling device.

[0021] A vertical limiting roller is installed at the outlet of the segmented cooling device. The vertical limiting roller guides the corrected material into the drying device to remove moisture.

[0022] A vertical limiting roller is installed at the discharge port of the air-drying device. The air-dried material is guided and enters the discharge roller conveyor, waiting to be hoisted and framed.

[0023] Several vertical guide rollers are installed on the outer sides of the lifting roller conveyors A and B. These vertical guide rollers are used to prevent materials from falling off the equipment during lateral conveying, thus preventing safety accidents.

[0024] The non-contact orthodontic device's correction method includes the following steps:

[0025] S1. Measure the deformation data of the material to be corrected at room temperature to determine the parts, dimensions and correction amount that need to be corrected;

[0026] S2. Check the coefficient of thermal expansion of the material and determine whether the material is a thermally expanding material or a negatively expanding material;

[0027] S3. Based on the material properties and coefficient of thermal expansion determined in step S2, determine the cooling sequence and cooling medium flow rate parameters for each part of the material.

[0028] S4. The material is conveyed from the feed roller conveyor 1 to the heating and holding furnace;

[0029] S5. The material moves towards the station near the lifting roller conveyor B via the transverse transfer device, and is simultaneously heated and kept warm to the preset temperature.

[0030] S6. The heated material from step S5 is output to the segmented cooling device via the lifting roller conveyor B.

[0031] S7. Based on the parameters determined in step S3, perform a traveling non-contact cooling correction on the material in the cooling device.

[0032] S8. After the straightening is completed, the material is sent out through the roller conveyor and the drying device is used to continue cooling the material to room temperature and drying it to obtain the straightened material.

[0033] The non-contact straightening process is carried out simultaneously with the solution quenching heat treatment of the material. Since the non-contact straightening process is a pure cooling process, its effect is similar to that of solution quenching heat treatment. The simultaneous execution of the two processes greatly simplifies the process and improves production efficiency.

[0034] The working principle of this invention is as follows:

[0035] The material to be corrected is continuously fed into the heating and holding furnace through the feed roller conveyor for heating and holding, and then continuously output to the segmented cooling device through the discharge roller conveyor for online motion cooling, and the cooling sequence of each part of the material is controlled.

[0036] For thermally expanding (thermal expansion and contraction) materials, in the initial cooling stage (first cooling channel), the deformation side A of the material is controlled to cool and contract first, causing the material to deform towards the deformation side A; in the middle cooling stage (second cooling channel), the opposite deformation side B of the material is controlled to cool and contract later, causing the material to deform towards the opposite deformation side B and thus return to the initial state before correction; in the later cooling stage (third cooling channel), the opposite deformation side B of the material is controlled to continue cooling and contracting, causing the material to continue deforming towards the opposite deformation side B, thereby offsetting the original deformation of the material;

[0037] The deformation principle is as follows: During the cooling and shrinkage process of the deformation side A, its shrinkage process is restricted due to the restraint of the rest of the material, resulting in a smaller amount of cooling and shrinkage than the normal shrinkage amount when the material is uniformly cooled; During the cooling and shrinkage process of the deformation-opposite side B, its shrinkage process is promoted due to the compressive force applied during the cooling and shrinkage of the deformation side A, resulting in a larger amount of cooling and shrinkage than the normal shrinkage amount when the material is uniformly cooled; Finally, because the shrinkage amount of the deformation-opposite side B after the material cools to room temperature is greater than the shrinkage amount of the deformation side A, the material deforms towards the deformation-opposite side B during the correction process, thereby offsetting the original deformation of the material and achieving the purpose of non-contact correction.

[0038] For materials with negative thermal expansion (thermal contraction and cold expansion), in the initial stage of cooling (first cooling channel), the deformation-opposite side B of the material is controlled to cool and expand first, causing the material to deform towards the deformation side A; in the middle stage of cooling (second cooling channel), the deformation-opposite side A of the material is controlled to cool and expand later, causing the material to deform towards the deformation-opposite side B, thus restoring it to its initial state before correction; in the later stage of cooling (third cooling channel), the deformation-opposite side A of the material is controlled to continue cooling and expanding, causing the material to continue deforming towards the deformation-opposite side B, thereby offsetting the original deformation of the material.

[0039] The deformation principle is as follows: During the initial cooling and expansion of the opposite side B, the expansion process is restricted due to the constraint of the rest of the material, resulting in a smaller amount of cooling and expansion than the normal expansion during uniform cooling. During the subsequent cooling and expansion of the opposite side A, the expansion process is promoted due to the tensile force applied during the initial cooling and expansion of the opposite side B, resulting in a larger amount of cooling and expansion than the normal expansion during uniform cooling. Ultimately, because the expansion of the opposite side A after the material cools to room temperature is greater than the expansion of the opposite side B, the material deforms towards the opposite side B during the correction process, thereby offsetting the original deformation of the material and achieving the purpose of non-contact correction.

[0040] The beneficial effects of this invention are:

[0041] 1. This invention utilizes a segmented cooling device. Based on the thermal expansion (or negative thermal expansion) characteristics of the material and the principle of internal thermal stress, it controls the cooling sequence of different parts of the material during the cooling process. By utilizing the internal thermal stress generated by the temperature gradient within the material, the material undergoes cooling deformation to one side. This cooling deformation counteracts the original deformation defects of the material, achieving non-contact straightening. It eliminates the need for external clamping or pressure equipment such as straightening rollers, avoiding damage to the material caused by traditional straightening clamping and pressure equipment. The straightening efficiency is high, and the dimensional accuracy and surface quality of the straightened material are guaranteed.

[0042] 2. The correction process of this invention is a continuous correction, which can realize continuous production and dynamic monitoring. It has high correction production efficiency and high degree of automation. By adjusting the flow rate of the nozzle, it utilizes the characteristic that the spraying intensity is proportional to the cooling intensity to complete the non-contact correction of materials with different thermal expansion coefficients. It has a wide range of applications and is particularly suitable for the non-contact correction of aluminum alloy plates and strips of various alloy series.

[0043] 3. For heat-treatable materials, the present invention can also perform solution quenching treatment simultaneously during the straightening process, thereby reducing processing steps, improving processing efficiency, and reducing energy consumption.

[0044] 4. In the traditional aluminum sheet and strip profile production process, offline or online stretching and straightening equipment is usually set up. When the flatness and straightness of the sheet and strip profile are insufficient, it is necessary to hoist or transfer it to the stretching and straightening equipment for clamping and stretching. After stretching, the clamping part (the surface has been scratched by the clamping jaws) must be sawn off, resulting in extremely low production efficiency. After using this invention, the investment in stretching and straightening equipment can be reduced or eliminated, saving a lot of equipment costs for aluminum material production and processing enterprises.

[0045] 5. This invention also avoids the consequences of scrapping due to improper setting of the stretching ratio in the traditional stretching and straightening process, thus improving the yield of the straightened product. Attached Figure Description

[0046] Figure 1 This is a flowchart of the non-contact orthodontic process;

[0047] Figure 2 This is a plan view of the non-contact correction device of the present invention;

[0048] Figure 3 This is a plan view of the internal structure of the non-contact correction device of the present invention.

[0049] Figure 4 This is a schematic diagram illustrating the process of thermal expansion material correction of material changes.

[0050] Figure 5A schematic diagram illustrating the process of correcting material changes using a negative thermal expansion material.

[0051] The markings in the diagram are: 1-feed roller conveyor; 2-heating and heat preservation furnace; 21-lifting roller conveyor A; 22-translation chain; 23-lifting roller conveyor B; 3-discharge roller conveyor; 4-segmented cooling device; 41-first cooling channel; 42-second cooling channel; 43-third cooling channel; 5-drying device; 51-guide roller. Detailed Implementation

[0052] Example 1

[0053] A non-contact correction device includes a heating and heat preservation furnace 2. The outlet of the heating and heat preservation furnace 2 is connected to a segmented cooling device 4. The segmented cooling device 4 includes a first cooling channel 41, a second cooling channel 42, and a third cooling channel 43. Each cooling channel has several air nozzles, mist nozzles, or water nozzles arranged in the up, down, left, and right directions inside its cavity.

[0054] The amount of cooling medium sprayed from the air nozzle, mist nozzle, or water nozzle can be independently adjusted by the flow valve in the pipeline.

[0055] The inlet of the heating and heat preservation furnace 2 is connected to the feed roller 1, the outlet of the segmented cooling device 4 is connected to the air drying device (5), and the other end of the air drying device 5 is connected to the discharge roller 3.

[0056] The inner cavity of the heating and heat preservation furnace 2 is sequentially equipped with lifting roller conveyor A21, translation chain 22 and lifting roller conveyor B23 according to the material movement direction. Lifting roller conveyor A21 is connected to the feeding roller conveyor 1 and lifting roller conveyor B23 is connected to the inner roller conveyor of the segmented cooling device 4.

[0057] The heating and heat preservation furnace 2 contains several temperature control zones, each of which is equipped with a heating device, a circulating fan, and a temperature control thermocouple.

[0058] The segmented cooling device 4 is equipped with a vertical limiting roller at the discharge port.

[0059] A vertical limiting roller is installed at the discharge port of the air-drying device 5.

[0060] Several vertical baffle rollers are provided on the outer sides of the lifting roller conveyor A21 and lifting roller conveyor B23.

[0061] The non-contact orthodontic device's correction method includes the following steps:

[0062] S1. Measure the deformation data of the material to be corrected at room temperature to determine the parts, dimensions and correction amount that need to be corrected;

[0063] S2. Check the coefficient of thermal expansion of the material and determine whether the material is a thermally expanding material or a negatively expanding material;

[0064] S3. Based on the material properties and coefficient of thermal expansion determined in step S2, determine the cooling sequence and cooling medium flow rate parameters for each part of the material.

[0065] S4. The material is conveyed from the feed roller conveyor 1 to the heating and holding furnace;

[0066] S5. The material moves towards the station near the lifting roller conveyor B via the transverse transfer device, and is simultaneously heated and kept warm to the preset temperature.

[0067] S6. The heated material from step S5 is output to the segmented cooling device via the lifting roller conveyor B.

[0068] S7. Based on the parameters determined in step S3, perform a traveling non-contact cooling correction on the material in the cooling device.

[0069] S8. After the straightening is completed, the material is sent out through the roller conveyor and the drying device is used to continue cooling the material to room temperature and drying it to obtain the straightened material.

[0070] The non-contact straightening process is carried out simultaneously with the solution quenching heat treatment of the material.

[0071] Application Examples:

[0072] The following is a detailed explanation using a specific example, taking a 10mm thick and 450mm wide 7175 aluminum alloy sheet as an example:

[0073] (1) The deformation data of the board at room temperature is: the bottom of the board cross section deforms upward by 3mm. The part, size and amount of correction to be determined are: the entire cross section of the board is corrected downward to a plane.

[0074] (2) The coefficient of thermal expansion of 7175 aluminum alloy sheet is 23.6 x 10⁻⁶. -6 / ℃, belongs to thermal expansion materials.

[0075] (3) The cooling sequence of each part of the material is determined as follows: In the early stage of cooling, the deformation side (bottom) of the plate is controlled to cool and shrink first, so that the plate deforms to the deformation side (bottom); in the middle stage of cooling, the opposite side (top) of the material is controlled to cool and shrink later, so that the material deforms to the opposite side (top) and thus returns to the initial state before correction; in the later stage of cooling, the opposite side (top) of the material is controlled to continue to cool and shrink, so that the material continues to deform to the opposite side (top) and thus offsets the original deformation of the material; the cooling correction parameters are: the heating and heat preservation furnace is set at 470℃ and heat preservation for 30 minutes; the segmented cooling device 4 uses water cooling for the front section 41-, and the nozzle water volume parameters are 20% for the top, 80% for the bottom, 0% for the left, and 0% for the right; the middle section 4-2 uses water cooling, and the nozzle water volume parameters are 80% for the top, 20% for the bottom, 0% for the left, and 0% for the right; the rear section 4-3 uses water cooling, and the nozzle water volume parameters are 60% for the top, 40% for the bottom, 0% for the left, and 0% for the right.

[0076] (4) The sheet material is continuously conveyed from the feed roller conveyor 1 to the heating and heat preservation furnace 2.

[0077] (5) Heat and keep the board at a temperature of 470℃ for 30 minutes.

[0078] (6) The sheet material is continuously output to the segmented cooling device 4 through the discharge roller conveyor 3, with a roller conveyor output speed of 5m / min.

[0079] (7) Perform continuous non-contact cooling correction on the plate according to the nozzle water volume parameters determined in (3) above.

[0080] (8) Use the air drying device 5 to continue cooling the board to room temperature and blow it dry to obtain a board with a flat cross-section after correction.

Claims

1. A non-contact correction method, characterized in that: The non-contact correction device includes a heating and heat preservation furnace (2), the outlet of which is connected to a segmented cooling device (4). The segmented cooling device (4) includes a first cooling channel (41), a second cooling channel (42), and a third cooling channel (43). Each cooling channel has several air nozzles, mist nozzles, or water nozzles installed in the upper, lower, left, and right directions. The inner cavity of the heating and heat preservation furnace (2) is provided with lifting roller A (21), translation chain (22) and lifting roller B (23) in sequence according to the material movement direction. Lifting roller A (21) is connected to the feeding roller (1), and lifting roller B (23) is connected to the roller in the segmented cooling device (4). The correction process of the non-contact correction device is carried out simultaneously with the solution quenching heat treatment of the material; The correction method using a non-contact orthodontic device includes the following steps: S1. Measure the deformation data of the material to be corrected at room temperature to determine the parts, dimensions and correction amount that need to be corrected; S2. Check the coefficient of thermal expansion of the material and determine whether the material is a thermally expanding material or a negatively expanding material; S3. Based on the material properties and coefficient of thermal expansion determined in step S2, determine the cooling sequence and cooling medium flow rate parameters for each part of the material. S4. The material is conveyed from the feed roller conveyor to the heating and holding furnace; S5. The material moves towards the station near the lifting roller conveyor B via the translation chain, and is simultaneously heated and kept warm to the preset temperature. S6. The heated material from step S5 is output to the segmented cooling device via the lifting roller conveyor B. S7. Based on the cooling medium flow parameters determined in step S3, perform non-contact cooling correction on the material in a segmented cooling device. S8. After the straightening is completed, the material is sent out through the roller conveyor and the drying device is used to continue cooling the material to room temperature and drying it to obtain the straightened material.

2. The non-contact correction method according to claim 1, characterized in that: The amount of cooling medium sprayed from the air nozzle, mist nozzle, or water nozzle can be independently adjusted by the flow valve in the pipeline.

3. The non-contact correction method according to claim 1, characterized in that: The inlet of the heating and heat preservation furnace (2) is connected to the feed roller conveyor (1), the outlet of the segmented cooling device (4) is connected to the air drying device (5), and the other end of the air drying device (5) is connected to the discharge roller conveyor (3).

4. The non-contact correction method according to claim 1, characterized in that: The heating and heat preservation furnace (2) contains several temperature control zones, each of which is equipped with a heating device, a circulating fan and a temperature control thermocouple.

5. The non-contact correction method according to claim 1, characterized in that: The segmented cooling device (4) is equipped with a vertical limiting roller at the discharge port.

6. The non-contact correction method according to claim 3, characterized in that: The air-drying device (5) is equipped with a vertical limiting roller at the discharge port.

7. The non-contact correction method according to claim 1, characterized in that: Several vertical baffles are provided on the outer sides of the lifting roller conveyor A (21) and the lifting roller conveyor B (23).

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